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• Installed demonstrator: high-temperature heat pump with mine thermal energy storage. • Proof of concept for a 2-stage 500 kW ammonia-butane heat pump that delivers 120°C. • Tests proved that the flooded mine is suitable for heated seasonal storage facility. • Heat pump factory tests with 70 K temperature lift showed high performance. • CO 2 emission reduction by means of a solar and geothermal integrated energy system. The research aims to prove that renewable energy sources in the heating sector can enable the energy transition towards European and German CO 2 reduction targets. To do so, at the premises of the Fraunhofer IEG Institute in Bochum a demonstrator for high-temperature heat pumps (HTHPs), coupled with seasonal high-temperature mine thermal energy storage (MTES), was developed. The goal is achieved by demonstrating the feasibility of the technology by connecting mine water present in a small flooded coal colliery (MTES) to solar parabolic trough collectors (SPTCs) and also to a HTHP system that serves the local district heating (DH) grid of Bochum south. The MTES, with an estimated water volume of approximately 20000 m3 is employed as seasonal storage for a 500 kW HTHP system that can reach a supply temperature of 120°C, as needed by the existing DH grid when the ambient temperature is lower or equal to -10°C. During the summer operation, the heat is injected into the MTES from the SPTCs to obtain a mine water temperature of 60°C; and in the winter operation, the heat is extracted through the HTHP until the mine water reaches the unheated temperature of 12°C at the end of the heating season. A literature review of the main components of the plant, the description of the installed system parts and performed tests are reported, along with the results of the successfully executed tests. [ABSTRACT FROM AUTHOR]

• Three parallel compressors more efficient than two variable speed compressors. • R452B versus R410A led to better efficiencies and compatibility at high ambient. • Reliable oil return of three parallel compressors having multiple capacity levels. • Three parallel centrifugal blowers led to improved air flow distribution. This study delineates a meticulous exploration of technologies to enhance the energy efficiency of rooftop air conditioning units, employing the DOE/ORNL heat pump design model for comprehensive engineering design and optimization. A baseline rooftop air conditioning unit, featuring a 13 ton (45.7 kW) cooling capacity and a 17.9 integrated energy efficiency ratio, served as the point of departure for substantive efficiency enhancements. Key modifications included the consolidation of two refrigerant circuits into one, integrating three parallel 2-stage (dual-speed) compressors, fan replacements with high-efficiency substitutes. Notably, a lower global warming potential refrigerant, R452B, was evaluated as a substitute for R-410A, demonstrating better performance in the lab prototype. The achieved measured integrated energy efficiency ratio of 21.4 in the lab prototype surpassed the baseline integrated energy efficiency ratio. Comparative evaluations between R410A and R452B indicated heightened efficiency with the latter, showcasing a lab-demonstrated integrated energy efficiency ratio of 22.4 at the rated capacity of 13.8 ton (48.5 kW) and 23.9 integrated energy efficiency ratio at the rated capacity of 10 ton (35.2 kW). This research underscores the successful development of a rigorous, energy efficient rooftop air conditioning unit prototype with noteworthy environmental and economic implications. [ABSTRACT FROM AUTHOR]

• The operating performances of a CASHP in LTS and HTS were tested. • Compressor speed plays opposite roles in LTS and HTS to affect the pressure ratio and COP. • Changes of the compressor speed in LTS failed to improve the COP of a CASHP unit. • Empirical models predicting COP in LTS and HTS were established. Previous studies on cascade air source heat pumps (CASHPs) mainly focused on overall performances, while impacts of the low temperature stage (LTS) and high temperature stage (HTS) on overall performances were paid less attention to. Therefore, operating performances of a CASHP in LTS and HTS were investigated in this paper, to provide a solution for the optimization of the CASHP. A CASHP unit with a variable speed compressor in LTS and a constant speed compressor in HTS was adopted, and its operating performances were investigated under 26 cases. Results showed that the pressure ratio and COP in LTS and HTS were affected differently by the compressor speed. Specifically, as the speed of the compressor in LTS increased from 30 rps to 90 rps, P rL increased by 151 % ∼ 178 %, and P rH reduced by 38 % ∼ 54 %. Meanwhile, COP in LTS reduced by 21 % ∼ 52 %, but the COP in HTS rose by 54 % ∼ 96 %. Besides, it was found that adjustments of the compressor speed in LTS could improve heating performances of the CASHP. However, when the ambient air temperature and the supply water temperature were consistent, COP changes of the CASHP were limited, only by 0.3 % ∼ 9 %. Furthermore, empirical models of the COP in LTS and HTS were established to predict the COP of the CASHP on different operating conditions. Results of this study were helpful in promoting the configurations and operation control optimization of CASHPs. [ABSTRACT FROM AUTHOR]

Passive ultra-low energy buildings represent an effective strategy for energy conservation and emission reduction within the global building industry. The prolonged and cold winters in severely cold regions of China necessitate substantial heating energy consumption. The study utilized a combination of overall surveys and long-term tracking surveys to evaluate the indoor environment and energy consumption in a passive office building situated in severely cold region under different heating modes over 2 years. The results show that the average temperature and indoor air quality (IAQ) can meet the standards at most moments. However, the average relative humidity tends to fall below the specified lower limit. Nevertheless, the Predicted Mean Vote (PMV) index suggests that the indoor environment provides a comfortable thermal experience for humans. The heat pump air conditioning (HPAC) system operation revealed that when the outdoor air temperature fell below −7°C, the coefficient of performance (COP) of the air source heat pump units would deteriorate. Implementing intermittent heating during the second year can reduce heating energy consumption by 13.4 kWh/(m2·a), resulting in 38.9% energy savings. These findings will serve as a valuable reference for the design and operation of heating systems in passive buildings in severely cold regions. [ABSTRACT FROM AUTHOR]

Combining mine exhaust waste heat with existing heat pump technology is a promising technical route to realise the efficient extraction and scientific use of low-grade waste heat resources in mines and to solve the problem of insufficient heat supply in remote mining areas. This study proposes a new type of mine-exhaust-air heat exchange coupled with heat-pump waste-heat-utilisation system based on deep enthalpy heat extraction. Using a mining area in Northwest China as a representative case, this study establishes a systematic exergy analytical model and a thermo-economic model. Through an in-depth analysis of the different evaporation temperatures and condensing temperatures, the system's energy efficiency ratio (COP) reaches its optimal performance, with the total exergy efficiency surpassing 90%. The minimum efficiency of the subsystem return air heat exchanger is 35%. The unit thermal costs of the mine exhaust air waste heat utilisation system and a conventional coal-fired boiler system are 0.1291 and 0.1573 million RMB/kW·h, respectively. This is a thermal economics cost saving of 21%. The studied system demonstrates great economic viability and the potential for energy saving throughout its life cycle. [ABSTRACT FROM AUTHOR]

Carbon capture and storage can reduce the carbon emission directly and effectively. Absorption carbon capture (ACC) is currently the most promising way to remove CO2 from coal-fired power plant, yet the main drawback is the excessive thermal energy consumption for the regeneration process. In this study, a new ACC system that utilizing the low-grade waste heat to generate steam has been proposed, in which system the steam is compressed to increase the saturation temperature to satisfy the thermal energy grade demand of the absorbent regeneration. Heat pump is introduced to increase the inlet pressure and enhance the energy and economic effect of vapor compression and R245fa is found suitable for the system. The vapor generating work can be controlled below 200 kWh t−1 when Twh is higher than 60°C, and COPvg can be higher than 3.5 for situations of Ttag,sat not exceeding 130°C. The energy performance and economic analysis of the proposed ACC system driven by the new vapor generation method is analyzed. Off-peak operation by ASS shows good economic effect, the operating cost for the regeneration process of carbon capture is only 69.70 CNY t−1 CO2 under the worst condition and far below the traditional heating method. The new heat supply method for carbon capture presents reasonable energy and economic performance, which is shown suitable for peak shifting of the power grid. [ABSTRACT FROM AUTHOR]

A novel methanol steam reforming system is proposed to enhance the utilization efficiency of waste heat in hydrogen production from methanol. The system is integrated with a monoethanolamine carbon capture system and a two-stage compression heat pump system. In this integrated system, the high-temperature products of the methanol steam reforming system exchange heat with the feedstock and undergo gas-liquid separation. The low-temperature gas produced is pre-compressed and utilized for heating the feedstock. Furthermore, a two-stage heat pump uses the low-temperature lean solution from the carbon capture system as a heat source for feedstock heating. The analysis is conducted based on a hydrogen production capacity of 200 kg/h, revealing an enhanced energy and exergy efficiency of 5.4% and 3.5%, respectively, compared to the reference system. Additionally, waste heat utilization efficiency increases from 62.1% to 92.0%. The cost of hydrogen production is reduced from 3.089 $/kg to 2.054 $/kg, which is very close to the cost of hydrogen production without carbon capture. The exergoeconomic analysis indicates that the introduction of energy levels enhances the value of high-temperature steams, and the hydrogen production unit exergy of cost rate is elevated from 3.443 $/kWh to 4.411 $/kWh. The proposed system can readily harness low-grade waste heat and exhibits high thermodynamic efficiency, presenting a promising approach for low-energy-consumption methanol-hydrogen production. • A low-energy, low-carbon methanol-based hydrogen production system is introduced. • Waste heat utilization of the integrated system is enhanced from 62.1% to 92.0%. • The overall energy and exergy efficiencies of the system reach 86.7% and 77.3%, respectively. • Hydrogen production cost is reduced from 3.089 $/kg to 2.054 $/kg by recovering waste heat. [ABSTRACT FROM AUTHOR]

We have designed a separation process of isobutyl alcohol (52.0 mol%) and isobutyl acetate (48.0 mol%) mixture using conventional extractive distillation (ED) and extractive dividing‐wall column (E‐DWC) with the solvent dimethyl sulfoxide (DMSO). The binary mixture exhibits a minimum boiling azeotrope that is sensitive to pressure. Thermodynamic analyses have shown that the vacuum pressures work better compared to the atmospheric pressure when DMSO is the solvent. Based on the separation with a purity of 99.9 mol%, the E‐DWC process has resulted in 9.6 % and 4.8 % reductions in the total annual cost and CO2 emission rates, respectively, in comparison to the conventional method. After further intensification using the heat pump technique, the E‐DWC process with the solvent DMSO has provided more than 40.0 % reduction in energy consumption compared to the ED systems studied in the literature using the solvents butyl propionate and dimethylformamide. [ABSTRACT FROM AUTHOR]

Introduction: In Switzerland, heating accounts for 70% of a building’s energy consumption, mostly fueled by fossil sources. Recently, cantonal regulations have mandated the use of renewable energy in heating, making heat pumps more significant. This study examines how public and private actors can create or transform a business ecosystem to facilitate heat pump adoption in multifamily houses and which business models, resources, and activities are most effective to support this transformation. Methods: We conducted a literature review and 13 semi-structured interviews with experts in heat pumps and contracting business models. The interviews were analyzed using an ecosystem framework. Results: Our findings revealed three primary barriers to the adoption of heat pumps in MFHs: technical challenges, lack of expertise, and regulatory issues. In terms of contracting business models, high transaction costs and customer acceptance are significant obstacles. Additionally, we discovered that in Switzerland, contracting is predominantly offered by public-oriented organizations with ready access to capital. Discussion: The study emphasizes the necessity for collaboration among various actors to facilitate the implementation of contracting solutions with the goal of accelerating the adoption of heat pumps in multifamily housing. Key activities include generating the necessary expertise and standardizing large heat pumps in MFHs, central government efforts to harmonize and facilitate HP regulations across cantons, as well as active communication and sensitization of building owners and users. [ABSTRACT FROM AUTHOR]

Aiming at the problem of excessive energy consumption in the thermal regeneration system of a rectisol process in a certain petrochemical engineering company, process improvement is carried out. A closed heat pump distillation model was proposed, using NRTL thermodynamic model with annual total cost and thermodynamic efficiency as objective functions. Process parameters were optimized and their economic and environmental benefits were analyzed under different compression ratios. The research results show that closed heat pump distillation can effectively reduce the use of superheated steam and condensate when the compression ratio is 1.8, and the total energy consumption is reduced by 62.71% . When the investment payback period are 5 years and 8 years, annual total cost is reduced by 15.64% and 32.79%, respectively. The thermodynamic efficiency has been improved from the original 8.78% to 20.96%, which has excellent economic and environ-mental benefits, and the results of the study are expected to provide guidance for the development and design of advanced heat pump distillation technology. [ABSTRACT FROM AUTHOR]

Large scale heat pumps (LSHP) have seen a rapid proliferation in recent years, with projects and initiatives aimed at integrating electrically driven LSHP into existing district heating networks (DHN). The financial advantages have driven most LSHP installations to be powered by electricity generated by on-site cogeneration (CHP), given CHP's dominant role in DHN. This LSHP + CHP combination poses the question, to what extent ecological improvements, measured as a reduction in specific CO2 emissions through LSHP operation can be achieved, contingent on the source of electricity and heat source employed. In this paper, the LSHP + CHP combination was generally analysed under usage of exergy analysis and a 2nd law derived method is presented. This method allows to evaluate the magnitude of CO2 reduction through LSHP operation across all common heat sources in 1st to 4th generation DHNs in conjunction with CHP. Results show, that in LSHP + CHP combination, heat from LSHP using either of the 2 heat sources ambient air or surfaced water, inevitably comes with higher specific CO2 emissions over the CHP heat. Only when using a sufficiently hot and emissions-free heat source, the LSHP heat from a LSHP + CHP combination can yield to an annual best case of half the CO2 emissions of the CHP. Importantly, the choice of power source has a far more significant impact, as LSHP powered by electricity from renewable energy sources achieve more than an eight-fold reduction in emissions compared to the LSHP + CHP combination. Therefore, power consumption with sufficiently low specific CO2 emissions out of external source is imperative to fully realize the ecological benefit of LSHP in DHN, underlining that the successful heat transition through LSHP relies heavily on the transformation of the electricity supply. Highlights: Based on the 2nd law a methodology is derived around exergy analysis, that enables a universal assessment of the ecological benefit of LSHP powered by CHP (Chapter 3). Graphs to determine every possible combination are presented (Chapter 4). Results are drawn for the most common CHP & LSHP including the most common types of heat source to grasp the scope of the discussed problematic. Ecological impact of LSHP in DHN are shown for comparison for most common types of CHP and LSHP- heat sources. [ABSTRACT FROM AUTHOR]

AbstractIn order to solve the problems of low drying efficiency and poor drying quality existing in the current closed heat pump drying system (CHPD), a closed carbon dioxide heat pump drying system (CHPRD) with the function of combining rotor dehumidification was designed. This study investigates the drying kinetics and quality characteristics of CHPRD in low-temperature drying processes using mango as the drying material through experimental studies and theoretical analysis. The experimental results showed that the drying rate of CHPRD increased by 29% and 17.8%, the moisture removal rate per unit energy (SMER) by 14.2% and 12.5%, and the coefficient of performance (COP) by 17.3% and 12.0%, respectively, compared with that of CHPD in the low-temperature drying process with loading amounts of 400 and 450 g, respectively. In terms of drying quality, the rehydration factor (Rf) of CHPRD-dried mango slices increased by 6.0% and 5.0%, the ascorbic acid content increased by 15.0% and 14.4%, and the color difference (ΔE) was lower by 11.0% and 5.6%, respectively. These improvements indicate that CHPRD provides better drying kinetics and higher quality of dried material. Based on the experimental data, simulation fitting was conducted, revealing that the two-term model is the best mathematical model to simulate the drying characteristics of CHPRD for mango. [ABSTRACT FROM AUTHOR]

Methods and instrumentation for measuring grout quality in heat pump boreholes, including the measurement of groundwater flow through boreholes outside partly grouted borehole exchanger pipes, have been developed in the Czech Republic. A Semtex charge has also been developed to repair rock massifs, which reliably disconnects borehole exchanger pipes without severely harming the surrounding rock environment or buildings. The resulting hole can then be used for regrouting, thus preventing undesirable vertical water flow through the borehole. [ABSTRACT FROM AUTHOR]

Drying has been widely used to provide a longer shelf life for various agricultural products. The moisture content can be reduced to prevent the spoilage of harvested agricultural products, in order to inhibit the growth of bacteria, yeasts, and molds. Among them, the drying system of solar-assisted air source heat pumps has drawn much attention in recent years, due to excellent energy saving and high dried quality of products. However, solar energy can be badly wasted, when the water tank temperature cannot meet the drying requirement, because of the high drying temperature during the middle and last drying stage. In this study, a solar-assisted multi-heat source heat pump (SMSHP) drying system was proposed to incorporate a watersource evaporator into the existing solar-assisted air source heat pump drying system, in order to improve the economic, and environmental benefit and the utilization rate. The fuzzy analytic hierarchy process was used to develop the optimization model of the SMSHP drying system. The optimization variables were selected as the collector inclination Angle, collector area, water tank volume, heat pump power, water pump flow rate, and airflow rate. The economy, system performance, and energy efficiency were chosen as the optimization objectives of the model. After that, the multi-objective optimization function of the SMSHP drying system was established to obtain a total of 25 groups of optimal combinations after the orthogonal test. Moreover, the simulation model of the SMSHP drying system was developed using the TRNSYS software. The accuracy of the model was verified, according to the experimental platform. Then the 25 groups of optimal combination parameters were introduced into the TRNSYS simulation model of the SMSHP drying system. The optimal parameter group was obtained with the highest system performance. Finally, the optimal and original parameter sets were compared and analyzed to verify the practicability and reliability of the model. The results showed that only 20 groups of 25 optimization parameters met the requirements of the drying process. The relative humidity of the air in the drying room was too high to meet the system requirements in the rest 5 groups. The economy, system performance, and energy efficiency were compared on the 25 groups' optimization. The optimization objective function of the 10th group was the lowest, indicating the optimal objective function. In addition, the TRNSYS simulation also showed that the optimal combination of parameters met the requirement of the drying process. The optimization parameter group 10 was the optimal one. The optimal parameters were obtained: the collector inclination angle was 35 °, the collector area was 40 m², the water tank volume was 1.5 m³, the heat pump power was 10 kW, the water pump flow rate was 2700 kg/h, and the airflow rate was 3500 m³ /h. Compared with the TRNSYS simulation of the original and the optimal parameters, the cost of the SMSHP drying system was reduced by 4.78%, whereas, the system performance and energy saving were improved by 17.08%, and 9.41%, respectively. All indicators were comprehensively improved by 6.27%. The multi-objective optimization of the solar multi-heat source heat pump drying system was carried out using a fuzzy analytic hierarchy process and TRNSYS simulation analysis. The finding has an important guiding significance to improve the performance of solar combined heat pump drying systems. [ABSTRACT FROM AUTHOR]

Ground heat pump systems (GHPSs) are esteemed for their high efficiency within renewable energy technologies, providing effective solutions for heating and cooling requirements. These GHPSs operate by utilizing the relatively constant temperature of the Earth's subsurface as a thermal source or sink. This feature allows them to perform greater energy transfer than traditional heating and cooling systems (i.e., heating, ventilation, and air conditioning (HVAC)). The GHPSs represent a sustainable and cost-effective temperature-regulating solution in diverse applications. The ground heat exchanger (GHE) technology is well known, with extensive research and development conducted in recent decades significantly advancing its applications. Improving GHE performance factors is vital for enhancing heat transfer efficiency and overall GHPS performance. Therefore, this paper provides a comprehensive review of research on various factors affecting GHE performance, such as soil thermal properties, backfill material properties, borehole depth, spacing, U-tube pipe properties, and heat carrier fluid type and velocity. It also discusses their impact on heat transfer efficiency and proposes optimal solutions for improving GHE performance. [ABSTRACT FROM AUTHOR]

It is now widely confirmed by scientific evidence that greenhouse gas emissions must be reduced to counteract the effects of global warming. The production of heat for industrial purposes is responsible for 36.8% of world energy-related emissions due to the widespread use of fossil fuels. Heat pumps are a key technology in the transition towards more sustainable industrial processes. In this paper, a systematic review of the literature produced in the last 5 years in international journals regarding the integration of heat pumps in industrial processes is presented. Firstly, papers presenting innovative configurations for high temperature heat pumps (HTHP), i.e., heat pumps delivering temperatures in the range between 100 °C and 200 °C, suitable for many industrial processes but still under development, are reviewed. Then, papers reporting innovative solutions for the integration of heat pumps in specific industrial processes and sectors (e.g., distillation, drying, desalination, etc.) are analyzed. Finally, the literature about alternative low-GWP refrigerants for industrial heat pumps, both pure compounds and mixtures, is described. It is concluded that many progresses have been realized in the last 5 years (2020–2024) regarding the identification of innovative heat pumps for industrial applications, but further research is certainly required. [ABSTRACT FROM AUTHOR]

The uptake of low-carbon domestic heating systems is a significant strategy towards global targets of reducing greenhouse emissions and mitigating climate change. Pre-1900 hard-to-treat houses will still be existing in the next 25 years, and they have the greatest potential for improved energy-efficiency. This study investigates the potential of fabric retrofit to prepare an older, hard-to-treat house type for heat pump use. The house type was modelled in DesignBuilder and validated using the Ulster University test house. The wall, loft and floor insulation, as well as glazing upgrades can yield up to 50% reduction in heating demand for a hard-to-treat house type, thereby preparing it for heat pump installation. Additionally, upgrading insulation and glazing in line with the current building standards was cost-effective, with a net present value of approximately GBP 12,000. [ABSTRACT FROM AUTHOR]

A photovoltaic thermal panel (PV/T) is an integrated module that harnesses both photovoltaic and solar thermal technologies to convert solar energy into electricity and heat, thereby enhancing overall energy efficiency. This paper aims to explore the suitability of PV/T solar heat pump systems across various climate zones and assess their potential for widespread application. By analyzing the operating principles of an indirect expansion PV/T solar heat pump system in conjunction with the climate characteristics of different regions, MATLAB R2019b/Simulink software was employed to evaluate the photoelectric performance of PV and PV/T systems in representative cities across five distinct climate zones in China during typical winter days. Key metrics, such as power generation, hot water storage tank temperature, indoor temperature, and system COP, were chosen to assess the heating performance of the PV/T solar heat pump system. The findings indicate that the winter ambient temperature significantly affects the photoelectric efficiency of both the PV and PV/T systems. While higher latitudes with lower ambient temperatures yield greater photoelectric efficiency, the southern regions exhibit higher power generation during winter. The winter heating effectiveness of the PV/T solar heat pump system is mainly influenced by indoor and water tank temperatures, with Harbin's system performing the poorest and failing to meet heating demands, whereas Nanjing's system shows the best results. [ABSTRACT FROM AUTHOR]

The accurate optimisation of absorption chillers is often impeded by idealised models that overlook system interactions and machine complexities. This study introduces a validated mathematical description for predicting the primary indicators of non-idealised absorption chillers, accounting for factors such as the electrical work of the Solution Circulation Pump, entropy changes within the refrigerant cycle, and exergy losses. Validation against 13 years of data (2008–2021) from the University of Debrecen's absorption chiller indicated close agreement, with deviations within acceptable limits. The use of a solution heat exchanger shifted cooling indicators towards their minima. Sensitivity analyses indicated that a 2.5% reduction in condenser temperature increased COP by 41.3% and Cooling Exergetic Efficiency by 15.5%, while a 2.5% reduction in the Heat Fraction Factor improved both by 34%. Adjusting absorber temperature and Heat Fraction Factor down by 2.5%, alongside a 2.5% rise in generator temperature, resulted in a 100.8% increase in COP and a 52.8% boost in Cooling Exergetic Efficiency. These insights provide a solid foundation for future optimisation strategies in real-life absorption chiller systems. [ABSTRACT FROM AUTHOR]

The performance of heat pump systems for heating and cooling heavily relies on the thermal conditions of their reservoirs. This study introduces a novel thermal reservoir, detailing a 2017 project where the Municipality of Stavanger installed a heat exchanger system on the wall of a main wastewater tunnel beneath the city center. It provides a comprehensive account of the system's design, installation, and performance, and presents an Artificial Neural Network (ANN) model that predicts heat pump capacity, electricity consumption, and outlet temperature across seasonal variations in wastewater temperatures. By integrating domain knowledge with the ANN, this study demonstrates the model's capability to detect anomalies in heat pump operations effectively. The network also confirms the consistent performance of the heat exchangers from 2020 to 2024, indicating minimal fouling impacts. This study establishes wastewater heat exchangers as a safe, effective, and virtually maintenance-free solution for heat extraction and rejection. [ABSTRACT FROM AUTHOR]

Integration of heat pumps combined with thermal energy storage provides a key pathway to decarbonizing the energy supply in the industry when the processes are not operated continuously. Yet, this integration of such novel systems introduces control challenges due to added dependencies between different process streams. This work investigates the control problem of heat pumps coupled to stratified thermal energy storage that is integrated into non-continuous industrial processes. A two-layer control strategy is proposed, where, in the higher level, a model predictive controller is developed for energy management using a linear model of the non-linear process. The resulting optimization problem is a mixed integer quadratic program. The low-level control layer is defined with standard industry controllers. The overall system is tested using a dynamic simulation model for the entire process, demonstrating its performance in three different cases. The control strategy optimizes heat recovery while ensuring system operability. The study demonstrates successful disturbance rejection and cold starts, wherein 100% of the targeted heat recovery can be confirmed under nominal conditions. Further evaluation in laboratory or field trials is recommended, and alternative, yet-to-be-defined, control concepts may be compared to the proposed approach. [ABSTRACT FROM AUTHOR]

The energy sector in Poland is primarily based on fossil fuels, mainly coal. Hard coal mining is one of the most important industries in Poland. Hard coal deposits in Poland are found in three basins, but mining is currently carried out in the Upper Silesian Coal Basin (USCB) and the Lublin Coal Basin (LCB). The Upper Silesian Coal Basin is Poland's central hard coal basin, with the most significant coal production extending across Poland and the Czech Republic. Approximately 80% of proven hard coal resources in Poland are found in the Upper Silesian Coal Basin (USCB). There is a tremendous amount of water in active and abandoned hard coal mines, which must be drained daily. Relatively high temperatures characterize mine water. This study analyzed the geological and hydrogeological conditions of the Upper Silesian Coal Basin and determined the potential for the use of mine waters for energy purposes. Depending on the location of the mine, the volume of mine water inflow ranges from 1 to 60 m3/min. The temperature of the pumped water is between 13 and 25 °C. In Poland, several such pilot installations have already been created; it is worth taking a closer look at the following examples. Heat recovery from mine drainage water can significantly reduce atmospheric emissions, which is particularly important in mining areas affected by low emissions. Therefore, Poland must raise the issue of using mined water for energy purposes, especially when making decisions related to decommissioning mines and developing post-mining areas. [ABSTRACT FROM AUTHOR]

BACKGROUND: Goji berries, renowned for their nutritional benefits, are traditionally dried to extend shelf life and preserve quality. However, conventional drying methods often result in uneven drying, color loss and reduced rehydration capacity. This study investigates an innovative hybrid strategy combining ultrasonic–ethyl oleate (US+AEEO) pretreatment with heat pump drying (HPD) to enhance the drying process of Goji berries. RESULTS: Fresh Goji berries underwent US+AEEO pretreatment, which significantly disrupted the waxy layer, enhancing drying efficiency and water infiltration during rehydration. Compared to freeze drying (FD), HPD combined with US+AEEO pretreatment resulted in higher retention of total polyphenol content (TPC) and total flavonoid content (TFC) in the Goji soaking soup. Specifically, the HPD‐US+AEEO samples exhibited the highest TPC and TFC levels, significantly outperforming FD samples. Additionally, the DPPH and ABTS antioxidant assays demonstrated higher scavenging activities in HPD‐US+AEEO samples. The rehydration kinetics revealed that HPD samples had a superior rehydration rate and final moisture content compared to FD samples. Low‐field nuclear magnetic resonance and magnetic resonance imaging analyses confirmed enhanced water distribution and higher mobility in HPD‐US+AEEO samples. Scanning electron microscopy indicated a more porous structure in US+AEEO‐treated samples, facilitating better water absorption and functional component retention. CONCLUSION: The combination of US+AEEO pretreatment with HPD significantly improves the drying process of Goji berries, enhancing nutrient retention, color preservation and rehydration properties. This innovative drying method offers a promising solution for producing high‐quality dried Goji berries, benefiting both the food industry and health‐conscious consumers. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Confluent, a company based in Scottsdale, Arizona, has announced a partnership with ATI to invest over $50 million in expanding ATI's Nitinol melt and materials conversion infrastructure. This investment aims to meet the growing demand for medical Nitinol in various device markets. Furukawa Electric in Japan has announced the reorganization of its metal wire business to maximize synergy effects and increase corporate value. Liebherr-Aerospace in Germany has inaugurated a new building for surface treatment, equipped with state-of-the-art technology for coating processes. NEOTech, a leading provider of electronic manufacturing services, has acquired advanced 3D Computed Tomography equipment to enhance its process validation and failure analysis capabilities. Finally, Oerlikon has established an advanced coating technology center in New York to accelerate the development of high-temperature materials and coatings for the aerospace and gas turbine industries. [Extracted from the article]

Although water heating accounts for 14% of residential electricity usage, the impacts of different water-heating technologies on greenhouse gas emissions are poorly quantified. This article compares carbon emissions from three water-heating technologies—including electric-resistance water heaters (ERWHs), heat-pump water heaters (HPWHs), and gas-fired boilers—by combining high-frequency measurements with physically based models. Models based on heat transfer principles are forced with measured hot-water demands from multi-unit residential buildings and then paired with spatially explicit marginal emissions data to compute carbon intensities. A technology warming potential analysis is then conducted to assess impacts over a 100-year period accounting for both site and source emissions. The use of real-world data at high temporal resolution reveals variations in emissions that are overlooked by studies that use precomputed factors. While, on average, ERWHs emit 1.9–2.2 times and 3.8–4.1 times more than gas-fired boilers and HPWHs, respectively, relative performance varies by season. Estimates of carbon emissions obtained using high-frequency data are found to be 8.9–9.6% higher than those obtained using average emissions factors, owing to alignment between marginal emissions and water demand peaks. These observations are discussed in the context of recent policy changes affecting water-heating technologies. [ABSTRACT FROM AUTHOR]

Refrigerants are a critical component of air conditioning and heat pump systems, but their high global warming potential has led to increasing concerns about their environmental impact. This research quantifies leakage from Schrader valves commonly used in air conditioning equipment. These valves serve as access points for refrigerant circuits and are often cited by service technicians as a source of leaks, contributing to greenhouse gas emissions. The study conducted laboratory testing of Schrader valves using an innovative experimental apparatus that tracked pressure and temperature of nitrogen gas contained by the valve over a 64-h test. The study found that 8 out of 61 used Schrader valves tested leaked at rates that would result in substantial refrigerant loss (M = 1,280 g/yr, SD = 3,168 g/yr, range = 9.4 to 9,117 g/yr). Gasketed caps were found to prevent refrigerant loss. Combining a Schrader valve with a gasketed cap significantly reduces the risk of leaks, and their use should be encouraged in air conditioning systems. The methodology developed for estimating leak rates from Schrader valves could be applied to other components in refrigeration systems, contributing to more comprehensive efforts to reduce refrigerant emissions. [ABSTRACT FROM AUTHOR]

• A novel parameter is introduced to refine the refrigerant leakage theory. • The refrigerant leakage process carries a higher oil content is confirmed. • The effect of leakage mass flow rate on oil content is investigated. • The oil content is highest when refrigerant leaks from the high-pressure pipe. Refrigerant leakage is a situation that often occurs in refrigeration equipment such as heat pumps. However, certain alternative refrigerants, while exhibiting superior environmental performance, possess varying levels of flammability. The leakage of flammable refrigerants into confined spaces can pose a significant risk of explosion. The amount of lubricant in the leaking refrigerant will undoubtedly affect the flammability characteristics of the refrigerant. In this paper, the content of PVE32 oil in the leaking refrigerant during the operation of a heat pump was investigated. The results showed that, under the five leakage rate scenarios set up in the experiment, the oil concentration was highest when the leakage occurred at the condenser inlet and lowest when the leakage was at the evaporator outlet. During the leakage process of the experiment, as the mass flow rate of the leakage increased, the oil content in the early stage of the leakage increased, but the oil content in the late stage of the leakage decreased. The reasons for the change in oil content were analyzed by the oil circulation rate and the degree of phase separation. The decrease of the oil circulation rate and the change of the degree of phase separation were the key factors affecting the magnitude of the oil content as the leakage proceeded. The results of the study reveal the leakage characteristics of lubricating oil with refrigerant leakage. [ABSTRACT FROM AUTHOR]

• The solubility of R1234ze(E) and R1336mzz(E) in two lubricants was tested and compared. • Experimental solubility data were correlated by the NTRL activity coefficient model. • The Henry's constants of R1234ze(E) and R1336mzz(E) in PAG and POE were obtained. Trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) and trans-1,1,1,4,4,4-hexafluorobut-2-ene (R1336mzz(E)) are environmentally friendly working fluids with low global warming potential (GWP) that can be used in compression refrigeration and heat pump systems. In this study, a solubility measurement system was established to assess the solubility of R1234ze(E) and R1336mzz(E) in polyalkylene glycol ether (PAG) and polyol ester (POE) at temperatures (283.15–323.15 K). The Henry's constants for four binary systems R1234ze(E)/PAG, R1336mzz(E)/PAG, R1234ze(E)/POE, and R1336mzz(E)/POE were analyzed and compared. Additionally, The non-random two liquid (NRTL) activity coefficient model was applied to correlate the solubility data in this study. The results indicate that R1234ze(E) exhibits higher solubility in PAG lubricant, while R1336mzz(E) is more easily dissolved in POE lubricant. Moreover, the solubility of R1336mzz(E) in both PAG and POE lubricants shows greater sensitivity to pressure and temperature changes compared to R1234ze(E). The results reported in this study can serve as a valuable guide for the choice of suitable lubricants for R1234ze(E) and R1336mzz(E) in different applications. [ABSTRACT FROM AUTHOR]

• Condensation of zeotropic mixtures in horizontal tube were experimentally studied. • The processes of temperature glide and composition shift were demonstrated quantitatively. • The heat and mass transfer resistances were discussed. • Effects of vapor quality, mass flux and saturation temperature on heat transfer were presented. Zeotropic refrigerant blends have attracted wide interest due to their promises to reduce global warming potential as well as their potential ability to improve the performance of heat pumps and air conditioners. The complex phenomenon of non-isothermal phase change complicates condensation of zeotropic refrigerant mixtures and merits extensive investigation to better understand their performance profiles. The present work experimentally studied condensation heat transfer of R407C and R448A – two R134a-based zeotropic refrigerant mixtures – in a horizontal smooth tube, condensed by counter-current water cooling. Measurements for mass flux were in the range of 120 to 320 kg m −2 s −1 and saturation temperature in the range of 42 to 64 °C. Variation in refrigerant temperature and composition shift during condensation were quantitatively presented. The experimental data showed the effects of mass flux and saturation temperature on the heat transfer coefficients of R407C and R448A in different vapor quality regions. The analysis of heat and mass transfer resistances related to the flow regimes and refrigerant thermophysical properties provides a deep understanding of the condensation heat transfer of zeotropic refrigerant mixtures. The experimental data presented in this work are of value for the design of condensers. [ABSTRACT FROM AUTHOR]

Heat pumps (HPs) have become pivotal for heating and cooling applications, serving as sustainable energy solutions. Coupled with renewable energy sources (RES) to run the compressor, which is the major energy-consuming component, they contribute to eco-conscious practices. Notably, their adaptability to be supplied by either alternating (AC) or direct (DC) currents, facilitated through converters, makes them more flexible for versatile renewable energy (RE) applications. This paper presents a comprehensive review of converter topologies employed in various HP applications. The review begins by exploring previous applied photovoltaic (PV)-HP projects, focusing on the gaps in the literature concerning the employed converter topologies. Additionally, the review extends to include a broader examination of the converter topologies that could be employed on the source and load sides of a system powered by a mix of renewable energy sources, such as photovoltaics (PV), wind turbines (WTs), and energy storage systems (ESS), and analyzes their strengths and weaknesses. Special emphasis is given to understanding the various topologies of the power electronics converters in the context of HP applications. Finally, the paper concludes with a summary of the literature gaps, challenges, and directions for future research. [ABSTRACT FROM AUTHOR]

The Hewlett Packard Enterprise–Cray EX Frontier is the world's first and fastest exascale supercomputer, hosted at the Oak Ridge Leadership Computing Facility in Tennessee, United States. Frontier is a significant electricity consumer, drawing 8–30 MW; this massive energy demand produces significant waste heat, requiring extensive cooling measures. Although harnessing this waste heat for campus heating is a sustainability goal at Oak Ridge National Laboratory (ORNL), the 30 °C–38 °C waste heat temperature poses compatibility issues with standard HVAC systems. Heat pump systems, prevalent in residential settings and some industries, can efficiently upgrade low-quality heat to usable energy for buildings. Thus, heat pump technology powered by renewable electricity offers an efficient, cost-effective solution for substantial waste heat recovery. However, a major challenge is the absence of benchmark data on high-performance computing (HPC) heat generation and waste heat profiles. This paper reports power demand and waste heat measurements from an ORNL HPC data centre, aiming to guide future research on optimizing waste heat recovery in large-scale data centres, especially those of HPC calibre. [ABSTRACT FROM AUTHOR]

Frosting is a common phenomenon of the ASHP under the heating mode in winter, and the outdoor air flow rate flowing through the evaporator of the ASHP was always thought to be a major contributor. In order to validate its contribution, effects of outdoor fan airflow rate on the performance of air source heat pumps (ASHPs) were investigated under the winter heating condition. The experiment was conducted in a laboratory at the standard 2 °C air dry bulb temperature (DB)/ 1 °C air wet bulb temperature (WB) frosting condition, which enabled the analysis of the operating performance, frosting performance, and heating performance of the ASHP unit by changing the airflow rate of the outdoor fan. Results showed that as the airflow rate of the outdoor fan reduced from 100% to 36%, the operating performance decline and the elevated frosting-defrosting loss were observed. Meanwhile, both the frosting rate and the operating efficiency during frosting-defrosting cycles showed an increasing trend then followed by decreasing tendency. The maximum frosting rate and operating efficiency were 0.92 g/m².min and 2.92, respectively, which were observed at 74% airflow rate of the outdoor fan of the ASHP unit. The observation implied the existence of the "minimum frosting suppression airflow rate ". At 36% airflow rate of the outdoor fan of the ASHP unit, however, the performance of the ASHP unit was attenuated greatly, with the frosting-defrosting efficiency loss coefficient of 0.47, the heating capacity and COP reduction by 51.5 and 38.8%, respectively. These findings provided significant references to the optimization of ASHPs performance with variable airflow rate of the outdoor fan under frosting conditions. [ABSTRACT FROM AUTHOR]

This study proposes a novel onboard carbon capture system (OCCS) with reduced fuel consumption. The proposed system included a heat pump with an intermediate heat exchanger, a parallel compressor, and a steam compressor. The proposed system consumed 43% less fuel than the boiler for producing the same amount of steam, which was required for CO2 stripping. In addition, a blended solvent of amino methyl propanol (AMP) and piperazine (PZ) was applied to the OCCS. A rate-based process simulation indicated that this solvent resulted in 22% lower reboiler duty, compared to a monoethanolamine (MEA) solvent. Further, it was shown that the proposed OCCS with the heat pump and the AMP/PZ solvent achieved a reduction of approximately 50% in both fuel consumption and CO2 emissions along with 26.9 USD reduction for capturing one ton of CO2, compared to the OCCS with a boiler and MEA solvent. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of geothermal borehole heat exchangers (BHEs) in combination with ground-source heat pumps represents an important part of shallow geothermal energy production, which is already used worldwide and becoming more and more important. Different measurement techniques are available to examine a BHE field while it is in operation. In this study, a field with 54 BHEs up to a depth of 120 m below ground level was analyzed using fiber optic cables. A distributed temperature sensing (DTS) concept was developed by equipping several BHEs with dual-ended hybrid cables. The individual fiber optics were collected in a distributor shaft, and multiple measurements were carried out during active and inactive operation of the field. The field trial was carried out on a converted, partly retrofitted, residential complex, "Lagarde Campus", in Bamberg, Upper Franconia, Germany. Groundwater and lithological changes are visible in the depth-resolved temperature profiles throughout the whole BHE field. [ABSTRACT FROM AUTHOR]

The integration of renewable energy sources (RESs) is rapidly increasing within energy systems worldwide. However, this shift introduces intermittency and uncertainty on the supply side. To hedge against RES intermittency, demand-side flexibility introduces a practical solution. Therefore, further studies are required to unleash demand-side flexibility in power systems. This flexibility is relevant across various sectors of power systems, including residential, industrial, commercial, and agricultural sectors. This paper reviews the key aspects of demand-side flexibility within the residential sector. To achieve this objective, a general introduction to demand flexibility across the four sectors is provided. As a contribution of this paper, and in comparison with previous studies, household appliances are classified based on their flexibility and controllability. The flexibility potential of key residential demands, including heat pumps, district heating, electric vehicles, and battery systems, is then reviewed. Another contribution of this paper is the exploration of demand-side flexibility scheduling under uncertainty, examining three approaches: stochastic programming, robust optimization, and information-gap decision theory. Additionally, the integration of demand flexibility into short-term electricity markets with high-RES penetration is discussed. Finally, the key objective functions and simulation software used in the study of demand-side flexibility are reviewed. [ABSTRACT FROM AUTHOR]

This paper presents the results of the technical validation of an innovative prototype for drying alfalfa bales. It is based on a 4.1 kW Heat Pump (HP) that uses an advanced technology (optimized for extracting the humidity from the air) and is directly powered by a 6.6 kWp PV generator without grid or batteries support. The main technical challenges of this work were managing solar irradiance fluctuations due to cloud-passing and achieving good drying efficiency. The prototype has been validated for two consecutive drying campaigns in La Rioja (Spain). There were no abrupt stops generated by cloud-passing. The PRPV, which evaluates the performance of the PV system only during the periods when the PV energy can be used by the HP unit, presented values of 0.82 and 0.85, comparable to a well-performing grid-connected PV system. Although the bales' initial relative humidity (RH) ranged from 18 to 30%, all but one of them presented a final RH below 16%, which is the limit point to avoid fermentation. The drying times ranged from 1 to 5 h, and the specific energy consumption per liter of water extracted, from 0.7 to 1.46 kWh/L. These values are comparable to traditional diesel and grid-powered systems. It is worth noting that the agricultural drying market represented USD 1.7 billion in 2023. [ABSTRACT FROM AUTHOR]

As an efficient heating terminal, direct-condensation terminals are increasingly being applied. This study proposes novel direct-condensation heating panels with different aspect ratios, which have been optimized in structure and reduced in copper tube length. To quantify their thermal superiority, the proposed panels' thermal economic performance and system efficiencies are investigated. Compared with previous heating terminals, the vertical temperature difference provided by the proposed panels is reduced by 1.1 ± 0.2 °C, improving thermal comfort. Meanwhile, the system COP is competitive among existing direct-condensation heating terminals. The average heating capacity per cost of the proposed panels reaches 5.4 W/USD, which is 24.1%~46.3% higher than that of previous panels. In addition, the impact of the aspect ratio shows that the panel with a high ratio has advantages in thermal economic performance and system efficiencies. The annual running cost and the system task efficiency of the panel with a ratio of 2.22 are 74.81 USD and 48.5%, respectively, which are 4.7% lower and 0.9% higher than that with a ratio of 0.45, respectively. The developed direct-condensation heating panels help to optimize the heating technology of air source heat pumps, while the evaluation methodology and aspect ratio results are suitable for optimizing other heating terminals. [ABSTRACT FROM AUTHOR]

High energy consumption and operating costs have affected the development of green and efficient granary warehouses. In order to promote energy saving and emission reduction in the reconstruction of granaries, this paper proposes a special solar photovoltaic-ground source heat pump cooling system for grain warehouses. The study investigates the feasibility and energy-saving effects of this combined system in grain warehouses, aiming to achieve "zero energy consumption" and "zero emissions" for green storage. Bungalow warehouses are typically single-story buildings widely used in grain reservoir, characterised by large roof area and spacious room between building rows. These features facilitate installing both underground heat exchangers and solar photovoltaic panels. Compared with residential buildings, adquate space can enable the solar photovoltaic-ground source heat pump system to integrate more well with warehouse buildings, and provide more cooling and power capacity. In summer, the electricity generated by photovoltaic panels is primarily consumed by the ground source heat pume for grain warehouse cooling. Then, the electricity is transmitted to living and office buildings in the grain reservoir, meeting the lighting requirements. Finally, excess power is sold to the State Grid. During other seasons when cooling is not required, the generated electricity first supplies the living and office buildings, and extra power is sold to the State Grid, too. Therefore, operating costs can be reduced through the surplus electricity sale. To maximize the combined advantages of solar and geothermal energy technologies in low-temperature grain storage, it is essential to conduct thorough research and design focused on the function and structure characteristics of warehouse buildings. This study aims to achieve deeper energy savings in storage application with current technologies. Simulation software was used to analyze the operation characteristics of the proposed system. Firstly, according to the actual size and working conditions of a grain warehouse, a simulation model for an air source heat pump system was established using TRNSYS software, which was verified with test data, and the the temperature response mechanism used in later simulation was obtained. Then, a TRNSYS simulation model for the solar photovoltaic-ground source heat pump cooling system was developed, considering the temperature and humidity requirements for low-temperature grain storage. System performance was simulated by this model over short and long-term periods, computing its operational characteristics. Finally, the cooling system was evaluated according to operational performance, such as photovoltaic adaptability, economic efficiency, energy savings, and environmental benefits. The results show that after oneyear operation, the system maximum COP is 4.76 and the minimum value is 3.3; after ten-year running, the maximum COP is 3.96 and the minimum is 3.07. In one-year operation, the soil temperature around underground heat exchangers increased by 0.65℃, and after ten years, it increased by 5.4 ℃. Underground thermal balance is an important factor for long time working performance. To avoid continuous soil temperature rise, the system should include a cooling tower into the equipment or use the ground source heat pump for space heating in the office and living buildings during winter. The ratio of system annual power generation to consumption is 192% to 270% for the warehouse and the investment payback period is 7.8 years. With ground source heat pump system, the standard coal consumption for cooling grain is 1.2 kgce/(t·a), compared to 2.93 kgce/(t·a) for the air source heat pump system, resulting in an energy saving rate of 59%. Additionally, harmful emissions are reduced by 3,841 t/a annually. These findings indicate that the solar photovoltaic-ground source heat pump cooling system is more suitable for warehouses than traditional grain cooling methods. This research can be expected to provide theoretical support and design references for developing more efficient granary cooling systems. [ABSTRACT FROM AUTHOR]

This paper proposes a hybrid technique for optimizing Combined Cooling, Heating, and Power (CCHP) systems integrating a diverse set of components including geothermal heat pumps, gas turbines, absorption chillers/heaters, and photovoltaic/thermal collectors, along with storage units like batteries and water tanks. The innovation lies in combining the Capuchin Search Algorithm (CapSA) with the Wild Horse Optimizer (WHO) to concurrently optimize primary energy savings, cost reductions, and carbon dioxide emissions. Parametric distributions are used in probabilistic strategies to resolve uncertainty in solar radiation and building load. CapSA optimizes the CCHP system’s design, while WHO enhances its performance. The effectiveness of the proposed strategy is demonstrated through implementation in MATLAB, where it achieves an average ACSR (Average Comprehensive Saving Rate) enhancement of 5.48%. This numerical result highlights a substantial improvement over existing methodologies, showcasing the superior performance of the hybrid optimization approach in enhancing energy efficiency and environmental sustainability of CCHP systems. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, five drying methods (hot air drying [HD], light wave drying [LD], far infrared drying [FID], freeze drying [FD], and heat pump drying [HPD]) were applied to dry Sargassum fusiforme. The color, rehydration rate (RR), and volatile flavor substances of dried S. fusiforme were compared and analyzed, and the content, molecular weight (Mw), monosaccharide composition, and antioxidant activity of dried S. fusiforme crude polysaccharides (SFCPs) were analyzed. The results showed that S. fusiforme dried by different drying methods showed different colors. FD produced S. fusiforme with better RR (p < 0.05). The Mw of the SFCPs were 624.06, 534.86, 683.00, 1077.13, and 981.91 kDa, respectively, for HD, LD, FID, FD, and HPD. The Mw and DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) radical scavenging rates of SFCP‐FD were greater than those of the remaining four drying methods; however, the ABTS (2,2 ′‐azobis‐3‐ethylbenzothiazoline‐6‐sulfonic acid) and OH (hydroxyl) radical scavenging rates were highest in the SFCP‐HPD. GC‐IMS analysis showed that the drying method affected the content and composition of volatile flavor compounds. Principal component analysis (PCA) analysis indicated that the flavors of dried S. fusiforme were quite different from that of fresh S. fusiforme, and the flavors of HD, LD, and FID were similar, while the flavors of FD and HPD were similar. [ABSTRACT FROM AUTHOR]

Compared to conventional condensation dehumidification systems, a solar liquid desiccant air conditioning system (SLDAC) offers distinct advantages, enabling independent control of temperature and humidity while operating at low carbon levels. This paper proposes a low-carbon SLDAC thermal mass exchange model that uses an indirect evaporative cooling liquid dehumidifier and photovoltaic thermal and air source heat pump for combined driving of the solution regeneration process. The system simulation model was created using MATLAB and TRNSYS software. An experimental comparison was conducted between the dehumidification module and the regeneration module, and the system's performance was simulated with an airflow of 150 m3/h in the Tianjin area. The results indicate an average dehumidification efficiency of 44.03% and a regeneration efficiency of 40.80% throughout the cooling season. During the cooling season, the power generation of the system met the power demand and produced a surplus of 85.36 kWh, achieving overall self-sufficiency in power consumption. The optimized system's operating parameters were proposed, with regeneration temperatures of 57 °C in June and September and 65 °C in July and August. During the cooling season, the system's regeneration capacity exceeded its dehumidification capacity for 84.90% of the operating time. As a result of optimization, the system's carbon emissions were reduced by 59.35%. [ABSTRACT FROM AUTHOR]

The production of mushrooms is increasing at a rapid pace due to advanced production technologies and higher consumption throughout the world. The consumption of edible mushrooms has increased throughout the world due to its high nutritive value, texture and flavor. Mushroom cultivation in India is emerging as secondary agricultural based land independent enterprises with huge local and export market potential. The post harvest life of mushrooms is very limited due to high moisture content and water activity, microbial, enzymatic activity and biochemical reactions. Storage of fresh mushrooms is a major problem in Indian conditions due to the lack of a cold chain system in India. Preservation of mushroom is very essential for reducing post harvest loss and extending shelf life whilst maintaining nutritional and organoleptic qualities for consumer's acceptance and availability of products during off-season. Dehydration is the most popular and important technique to increase the shelf life of mushrooms by reducing moisture content up to a level at which undesirable charges are prevented. The drying techniques which have the great potential for the production of quality dried mushrooms and powders are solar drying, tray drying, vacuum drying, microwave-vacuum drying, freeze drying and heat pump drying. Pretreatment before drying seems to be an effective method of preservation of mushrooms with minimum changes in nutritional and sensory quality to increase consumer's acceptability and market potential of dehydrated mushrooms. This review gives the information on pretreatments, dehydration and quality of dehydrate mushrooms. [ABSTRACT FROM AUTHOR]

This work introduces two new thermally integrated pumped thermal energy storage (TIPTES) systems, including thermally integrated vapor compression heat pump (TIHP) as a charging cycle and dual‐pressure organic Rankine cycle (DPORC) and dual‐loop organic Rankine cycle (DLORC) as discharging cycles to investigate their capability of improving roundtrip efficiency compared with the basic ORC (BORC). The thermodynamic and economic performance of the proposed TIHP‐DPORC and TIHP‐DLORC are analyzed and compared with TIHP‐BORC using various working fluids. The multi‐objective multiverse optimization algorithm is conducted to ascertain the systems' optimum roundtrip efficiency and cost rate. Results indicate that at the same storage temperature, the TIHP‐DLORC gives the highest roundtrip and exergy efficiencies of 219.9% and 43.53% with R1233zd(E), indicating 6.69% and 8.04% improvements compared with the optimum TIHP‐BORC. Moreover, it shows the lowest levelized cost of storage (LCOS) and payback period (PP) of 0.160 $/kWh and 4.5 years, respectively, with a maximum net present value of 1.973 M$. Although the cost rate of TIHP‐DLORC is high, its excellent thermodynamic and economic performance compared with the existing TIPTES systems in the literature indicates that DLORC is a more appropriate candidate to be applied in the TIPTES systems. [ABSTRACT FROM AUTHOR]

This study investigates the usage of photovoltaic (PV) and thermal collectors separately to assist a heat pump for supplying domestic hot water (DHW). Usage of PV and thermal collectors together to assist a heat pump and experimentally validated simulation of an air source heat pump can be considered as novelty of this study. Firstly, experimental tests were performed in a climatic room to validate the developed simulation model. Four experimental parameters, namely the coefficient of performance of the air source heat pump, average tank temperature, and heat pump inlet and outlet temperatures have been used for the validation and the highest obtained deviation was 4.5%. Simulations were carried out by adding thermal collectors and photovoltaic panels in different combinations, with a maximum of three collectors to assist the heat pump that provides DHW. For scenarios with one and two solar components (PV or thermal), applying only thermal collectors was more efficient and economical for both with a payback of 3.9 years and 4.3 years, respectively. For the scenario with three solar components, although the system supported by one thermal and two photovoltaic collectors was the most efficient option, the system supported by three photovoltaic collectors was the most economical scenario with a payback period of 4.6 years. The study found that combining thermal and photovoltaic collectors can significantly reduce energy consumption for DHW. [ABSTRACT FROM AUTHOR]

This review aims to analyze recent advancements in heat pump dryers (HPDs) with a focus on improving energy efficiency and conservation in drying processes. The objective is to evaluate the components, structures, and refrigerants used in HPDs, examining their environmental impacts and system performance. The methodology includes a comprehensive comparison of various assisted HPD systems, such as infrared-, ultrasound-, and solar-assisted technologies, to assess their experimental benefits and limitations. By using key performance metrics, the paper evaluates the energy efficiencies of HPDs in comparison with traditional drying methods, discussing their applications across different industries. The study also explores the significance of integrating alternative energy sources to enhance the efficiency and economic viability of HPDs. Future research directions are proposed to further develop the technology for commercial use, emphasizing HPDs' potential to provide energy-efficient and high-quality drying solutions. In quantitative terms, the review notes that the coefficient of performance (COP) for HPDs ranges between 3.5 and 4.5, indicating a significant improvement over traditional drying methods. Specific moisture extraction rate (SMER) values for HPDs are reported to be between 0.8 and 1.2 kg kW−1 h−1, demonstrating superior efficiency in moisture removal. Additionally, specific energy consumption (SEC) for HPDs is found to be 0.5–0.7 kW h kg−1 of evaporated moisture, which is substantially lower compared to conventional dryers. These metrics underscore the energy-saving potential and enhanced performance of HPD technology. [ABSTRACT FROM AUTHOR]

Peltier cells are commonly used in low-power cooling applications, such as automotive refrigerators and electronics temperature regulation systems. These applications are typically low-energy in nature. There is currently a growing emphasis on energy conservation and waste heat utilization in the energy industry. This paper explores the possibility of improving the heating or cooling coefficient of performance (COP) of Peltier cells through intelligent serial and parallel connections. The purpose of this work is to raise the question of whether it would be possible to reconsider the concept of harnessing the "energy" potential of Peltier cells. The utilized model is in line with the current state of the art, and the case study is based on parameters measured on a commercially available Peltier cell. The resulting COP, when considering current materials, remains inferior to the COP of compressor-based heat pumps. For low-power devices, it can represent a technically and economically comparable solution. [ABSTRACT FROM AUTHOR]

The escalating utilisation of second homes has led to an extension in heating periods and, to a certain degree, renovations to elevate the standard, resulting in augmented energy and resource consumption. A comprehensive survey was conducted in Sweden, examining user patterns across different seasons, heating systems, and implemented energy efficiency measures. The results indicate that second homes are occupied for extended periods during the summer season and intermittently throughout the year. Over half of the second homes are heated even when unoccupied, with 12% maintaining a temperature above 16 °C. The predominant heating method is direct electricity (32.2%), followed by heat pumps (29.5%) and stoves (17.5%). A variety of renovations are undertaken, primarily to enhance the standard and technical performance, but also to implement energy efficiency measures such as window replacement, additional insulation, or heat pump installation. Based on the reported user and heating patterns, and the energy renovations carried out, the potential energy savings with different energy renovation strategies were estimated for the Swedish second home stock. The results show that though lowering the temperature when a second home is unoccupied emerges as the most efficient measure, both in terms of cost-effectiveness and climate impact, it needs to be complemented with intermittent heating or dehumidification to ensure that the relative humidity is below critical levels, to avoid the risk of damages caused by, for example, mould growth. Installing a heat pump is the second most energy- and cost-effective measure and has the advantage that the indoor temperature can be maintained at rather high levels. [ABSTRACT FROM AUTHOR]