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In this study, intensive calculations were performed to investigate the behavior of the low-temperature excess heat capacity of Cu50Zr50 ultrathin film metallic glasses. Our results show that there is a well-defined boson peak in the film metallic glasses and that the boson peak height exhibits an obvious size-dependent feature. Furthermore, there is a critical thickness dc in the curves between the boson peak height and the thickness, where the boson peak height changes abruptly. Through structural analysis, we found that the low-temperature excess heat capacity of the film metallic glasses is correlated with the density layering structure near the surface. The structural parameter S is defined by atomic density and it was found that the boson peak height is highly correlated with S. Our investigation of ultrathin film metallic glasses provides a deeper understanding about the structural origin of the boson peak in metallic glasses.

Lagos, Nigeria, is rapidly urbanizing and is one of the fastest-growing cities in the world, with a population that is increasing at almost 500 000 people per year. Yet the impacts on Lagos’s local climate via its urban heat island (UHI) have not been well explored. Considering that the tropics already have year-round high temperatures and humidity, small changes are very likely to tip these regions over heat-health thresholds. Using a well-established model, but with an extended investigation of uncertainty, we explore the impact of Lagos’s recent urbanization on its UHI. Following a multiphysics evaluation, our simulations, against the background of an unusually warm period in February 2016 (during which temperatures regularly exceeded 36°C), show a 0.44°C ensemble-time-mean increase in nighttime UHI intensity between 1984 and 2016. The true scale of the impact is seen spatially as the area over which ensemble-time-mean UHIs exceed 1°C was found to increase steeply from 254 km2 in 1984 to 1572 km2 in 2016. The rate of warming within Lagos will undoubtedly have a high impact because of the size of the population (12+ million) already at risk from excess heat. Significant warming and modifications to atmospheric boundary layer heights are also found in rural areas downwind, directly caused by the city. However, there is limited long-term climate monitoring in Lagos or many similarly expanding cities, particularly in the tropics. As such, our modeling can only be an indication of this impact of urbanization, and we highlight the urgent need to deploy instrumentation.

Industry accounts for about 30% of the final energy demand in Germany. Of this, 75% is used to provide heat, but a considerable proportion of the heat is unused. A recent bottom-up estimate shows that up to 13% of the fuel consumption of industry is lost as excess heat in exhaust gases. However, this estimate only quantifies a theoretical potential, as it does not consider the technical aspects of usability. In this paper, we also estimate the excess heat potentials of industry using a bottom-up method. Compared to previous estimates, however, we go one step further by including the corrosiveness of the exhaust gases and thus an important aspect of the technical usability of the excess heat contained in them. We use the emission declarations for about 300 production sites in Baden-Württemberg as a data basis for our calculations. For these sites, we calculate a theoretical excess heat potential of 2.2 TWh, which corresponds to 12% of the fuel consumption at these sites. We then analyse how much this theoretical potential is reduced if we assume that the energy content of sulphur-containing exhaust gases is only used up to the sulphuric acid dew point in order to prevent corrosion. Our results show that 40% of the analysed excess heat potential is corrosive, which reduces the usable potential to 1.3 TWh or 7% of fuel consumption. In principle, it is possible to use the energy of the excess heat from sulphur-containing exhaust gases even below the dew point, but this is likely to involve higher costs. This therefore represents an obstacle to the full utilisation of the available excess heat. Our analysis shows that considering corrosion is important when estimating industrial excess heat potentials.

In this work, the new set of the data on the excess heat capacity (CPE ), density (ρ) and excess volumes (VE) for binary system n-propanol + water in the temperature range 278.15–358.15 K are presented. The concentration dependence of CPE was correlated using Redlich–Kister equation. Obtained experimental data of CPE were used to calculate excess enthalpies at various temperatures.

Psoriasis is an inflammatory disease that changes plasma composition, and it is detectable by differential scanning calorimetry (DSC). Besides the general change in plasma, the aim of the study was to demonstrate which components are changing and how the anti-psoriatic drug treatment affects back all this. Retrospectively, blood plasma DSC data were analyzed from patients, who have different severities of symptoms and who received steroids (n = 10), or retinoids (n = 10), or biological drug treatment (n = 10). Complex curves were deconvoluted in several individual transitions (Tm1–Tm5), modeling each individual transition. In the examined psoriasis stages, the thermodynamic parameters excess heat capacity and enthalpy of the transitions in proportion corresponded to the targeted treatment and the degree of disease severity, as well as the numbers of transitions were determined from the calorimetric profiles. In conclusion, deconvoluted plasma DSC profiles showed similarities but exhibited marked differences in the thermal denaturation on different treated psoriasis stages. This examination has shown that drug therapy affects the composition of plasma proteins, which should be always considered for the evaluation of DSC results in similar studies.

In Sweden, over 50% of building heating requirements are covered by district heating. Approximately 8% of the heat supply to district heating systems comes from excess heat from industrial processe ...

Phase change material (PCM) can be integrated into floor heating system to store excess heat, releasing it when needed, thus effectively reducing the mismatch between energy supply and demand. In this study, a double pipe PCM floor heating system with three independent heating modules was proposed for clean energy heating in rural China. A 26-day experimental study was conducted to study the operation effect of the system under four different strategies. Strategy 1: partial power operation strategy; Strategy 2: daytime energy storage strategy; Strategy 3: nocturnal energy storage strategy; and Strategy 4: phased energy storage strategy. In the early stage of heating, the average temperature of experiment room was 18.9 °C and the daily temperature fluctuation was controlled within 2.1 °C, which showed an effective guarantee of indoor comfort under Strategy 1. In the late stage of heating, the differences in indoor temperature fluctuations could be caused by changes in outdoor climate and operation strategies. And operating strategy had less impact on indoor temperature distribution. Moreover, the experiment results revealed that the system could provide a comfortable indoor thermal environment while adjusting operational strategies. And the 3 °C average daily temperature fluctuation confirmed the feasibility of creating a comfortable environment with gentle temperature fluctuations via the PCM floor intermittent heating.

District heating systems already play an important role in increasing the sustainability of the heating sector and decreasing its environmental impact. However, a high share of these systems is old and inefficient and therefore needs to change towards the 4th generation district heating, which will incorporate various energy sources, including renewables and excess heat of different origins. Especially excess heat from industrial and service sector facilities is an interesting source since its potential has already been proven to be highly significant, with some researches showing that it could cover the heat demand of the entire residential and service sector in Europe. However, most analyses of its utilisation in district heating are not done on the hourly level, therefore not taking into account the variability of its availability. For that reason, the main goal of this work was to analyse the integration of industrial excess heat into the district heating system consisting of different configurations, including the zero fuel cost technologies like solar thermal. Furthermore, cogeneration units were a part of every simulated configuration, providing the link to the power sector. Excess heat was shown to decrease the operation of peak load boiler and cogeneration, that way decreasing the costs and environmental effect of the system. However, since its hourly availability differs from the heat demand, thermal storage needs to be implemented in order to increase the utilisation of this source. The analysis was performed on the hourly level in the energyPRO software

Strategic spatial planning is important for developing long-termvisions and strategies towards regional and local sustainability.This paper explores if and how strategic spatial planning could beuseful for overcoming some barriers related to new sustainableways of heating residential areas, using district heating systemsbased on industrial excess heat. This longitudinal study builds oninterviews with municipal and private actors in six Swedishmunicipalities. It highlights that important barriers can beovercome by influencing the design and location of residentialdistricts and industrial activities. Further, it identifies missedopportunities in local spatial planning practice as stakeholders areinvolved late in the planning when much is set, leaving littlespace for stakeholders to have an impact. Consequently, theremight be a lack of knowledge and expertise in how such issuescould enhance planning. Strategic spatial planning could facilitateconditions for excess heat-based systems of district heating as itimplies a broader systems perspective which could enhance abroader planning scope. Plan programs could bring about morestrategic spatial planning processes as these require earlystakeholder involvement. If taking stakeholder involvement onestep further to stakeholder collaboration or co-production, aneven broader planning scope would be achieved.

Small-scale steam methane reforming units produce more than 12% of all the CO2-equivalent emissions from hydrogen production and, unlike large-scale units, are usually not integrated with other processes. In this article, the authors examine the hitherto under-explored potential to utilise the excess heat available in the small-scale steam methane reforming process for partial carbon dioxide capture. Reforming temperature has been identified as a critical operating parameter to affect the amount of excess heat available in the steam methane reforming process. Calculations suggest that reforming the natural gas at 850 °C, rather than 750 °C, increases the amount of excess heat available by about 28.4% (at 180 °C) while, sacrificing about 1.62% and 1.09% in the thermal and exergetic efficiency of the process, respectively. Preliminary calculations suggest that this heat could potentially be utilised for partial carbon capture from reformer flue gas, via structured adsorbents, in a compact capture unit. The reforming temperature can be adjusted in order to regulate the amount of excess heat, and thus the carbon capture rate.

The traditional air distribution and supply devices in ventilated rooms are not always able to effectively remove excess heat from the space. Therefore, chilled beams, especially the active systems ...

This work deals with the mapping of industrial excess heat recovery through district heating. In this paper a methodology to estimate industrial waste heat recovery in a given territory is presented and applied. The method is particularly suitable for a relatively large, but limited, geographical region, with a significant number of industrial facilities. The multiplicity of available methodologies to calculate heat recovery from industrial energy consumptions and the related input data variety generate a wide range of results. The intent is to handle the variety of results and to include the uncertainty related to input data quality thanks to the application of Multicriteria Decision Analysis techniques. The presented methodology is then applied to a real case study of new district heating project in Italy. The plan is to connect the city of Milano to a large CHP plant 25 km far, which is currently wasting 80% of its rejected heat. The aim of the case study is to quantify the industrial excess heat that could be recovered along the new district heating. The elaborated methodology has been applied to estimate the recoverable heat potential in five alternative paths and to find the one allowing maximum recovery.

District heating companies have ambitious targets for lowering carbon emissions in production. Large heat pumps offer an interesting alternative for district heating production allowing utilization of various heat sources. The primary objective of this study is to examine the viability of large heat pumps in existing district heating systems. The study uses three types of systems to simulate how increasing the share of heat pump production influences district heating systems when optimized for the lowest production costs. The second objective of this study is to understand the district heating companies’ perspective on increasing amounts of heat pumps in their systems. Based on the simulations, the largest potential for heat pumps is in small district heating systems, where they reduce the use of fossil fuels. In medium and large systems with economical combined heat and power production, the potential of heat pumps is smaller. The findings of the simulations together with insights from the interviews imply that the viable amount of heat pump based heat production in DH systems would be around 10–25% in Finland, which is much higher than the current 3%.

In this paper we describe the approach of effective modification the substrate elements contributing to expansion of operating conditions of electronic devices. A method of local laser surfacing of heat-conducting materials on the surface of metal housings and substrates of radio-electronic products for obtaining the heat-transfer structures was used. The proposed method helps to reduce a thermal load on structural elements exposed to strong heating. The proposed approach is effective in cases where the usage of hinged heat sink elements or radiators are complicated by the design features or operating conditions of the device. In the work the materials and equipment used, the results of metallographic studies of the obtained structures and calculations of the thermal load of the electronic device are presented. The graphic material demonstrating an effectiveness of the approach of obtaining the heat-sinkregions for removing excess heat from the heated components of the device formed on the external metallic housing constructions ispresented.

Spark plasma sintering technique was used to consolidate solid solution of graphite–Ti (C0.9, N0.1) using ultrafine size of graphite and titanium carbonitride powder with carbon to nitrogen composition of 90:10 at 2000 oC for 5 mins. The densification of the sintered graphite (0-1 wt. %) –Ti (C0.9, N0.1) was 98-99% at 2000 oC in the matrix. The carbide rich and Ti rich were the two distinct solid solution phases observed, although Graphite –Ti (C0.9, N0.1) solid solution as a solitary phase was attained at 2000 oC. This could be attributed to changes in the parameters with in the lattice site due to excess heat and causing the solid solutions phases to favour the carbide and titanium phases, respectively. The graphite–Ti (C0.9, N0.1) solid solution upon the application of different load the value of the hardness decreases as the load increases for unreinforced and reinforced Ti (C0.9, N0.1). Furthermore, the fracture toughness (KIC ) was within the range of (1.04 – 7.99) in MPa m1/2.

Energy-intensive industries across the EU-28 release unused heat into the environment. This excess heat can be utilized for district heating systems. However, this is the exception today, and the potential contribution to the decarbonization of district heating is not well quantified. An estimation of excess heat, based on industrial processes, and spatial matching to district heating areas is necessary. We present a georeferenced industrial database with annual production and excess heat potentials at different temperature levels matched with current and possible district heating areas. Our results show a total potential of 960 PJ/a (267 TWh/a) of excess heat when the exhaust gases are cooled down to 25 °C, with 47% of the 1.608 studied industrial sites inside or within a 10 km distance of district heating areas. The calculated potentials reveal that currently 230 PJ/a (64 TWh/a) of excess heat is available for district heating areas, about 17% of today’s demand of buildings for district heating. In the future, widespread and low-temperature district heating areas increase the available excess heat to 258 PJ/a (72 TWh/a) at 55 °C or 679 PJ/a (189 TWh/a) at 25 °C. We show that industrial excess heat can substantially contribute to decarbonize district heating, however, the major share of heat will need to be supplied by renewables.

Ice and swimming halls annually consume lots of energy and produce significant amount of potential waste heat in Finland. In this paper, utilization of four possible waste heat sources (ice refrigeration, dehumidification of air, Gray water and exhaust air) is studied by simulating combined energy system of ice and swimming halls locating in Helsinki. Four cases were simulated including the reference case, one case with waste heat recovery and two cases with both waste heat recovery and two different exhaust air heat pumps. In addition, thermal energy storage tanks are used to store the excess waste heat from the ice hall, while the high temperature exhaust air heat pumps can raise the waste heat temperatures for all heat demands. The results show that up to 99% of the purchased district heat can be replaced by the waste heat in the ice hall at the cost of only 9% purchased electricity increase. The combined utilization of excess heat transferred from the ice hall and the waste heat from the swimming hall canresult in 72% reduction of purchased district heat and 37% electricity demand increase in the swimming hall. In the combined energy system of the studied ice and swimming hall, altogether 77% waste heat is utilized, bringing in 82% purchased district heat decrease and 25% electricity increase, while the total consumed energy reduced by 42%. In addition, the total annual energy cost savings reach 133 k€ (-29%), while the saving of the energy cost of the combined system can make up the maximum cost of the profitable investment. During three repayment periods (7, 10 and 15 years), the energy cost savings and maximum cost of profitable investment for the ice hall alone and combined ice and swimming halls are between 510 k€ and 970 k€ and between 700 k€ and 1 580 k€, respectively.

For any thermoelectric effects to be achieved, a thermoelectric material must have hot and cold sides. Typically, the hot side can be easily obtained by excess heat. However, the passive cooling method is often limited to convective heat transfer to the surroundings. Since thermoelectric voltage is proportional to the temperature difference between the hot and cold sides, efficient passive cooling to increase the temperature gradient is of critical importance. Here, we report simultaneous harvesting of radiative cooling at the top and solar heating at the bottom to enhance the temperature gradient for a transverse thermoelectric effect which generates thermoelectric voltage perpendicular to the temperature gradient. We demonstrate this concept by using the spin Seebeck effect and confirm that the spin Seebeck device shows the highest thermoelectric voltage when both radiative cooling and solar heating are utilized. Furthermore, the device generates thermoelectric voltage even at night through radiative cooling which enables continuous energy harvesting throughout a day. Planar geometry and scalable fabrication process are advantageous for energy harvesting applications., Graphical abstract

District heating is a well-established system for providing energy efficient space and domestic hot water heating in dwellings in particularly in temperate and cold climate zones. Research has shown that going from the current 3rd generation district heating (3GDH) systems towards 4th generation district heating (4GDH) systems can facilitate a better integration between energy sectors, reduce grid losses and assist the integration of renewable energy sources. This article investigates the economic and energy effects of going from 3GDH to 4GDH for the specific case of Aalborg Municipality, Denmark based on overall hourly energy systems simulations. The analyses include effects from changes in excess heat potentials, changes in grid losses, and changes in efficiencies of conversion units in the district heating. Altogether, the analyses of the Aalborg case reveal that going from 3GDH to 4GDH decreases the primary energy consumption of the entire energy system by around 4.5% and the costs of the system by 2.7%.

HT-ATES (high-temperature aquifer thermal energy storage) systems are a future option to shift large amounts of high-temperature excess heat from summer to winter using the deep underground. Among others, water-bearing reservoirs in former hydrocarbon formations show favorable storage conditions for HT-ATES locations. This study characterizes these reservoirs in the Upper Rhine Graben (URG) and quantifies their heat storage potential numerically. Assuming a doublet system with seasonal injection and production cycles, injection at 140 °C in a typical 70 °C reservoir leads to an annual storage capacity of up to 12 GWh and significant recovery efficiencies increasing up to 82% after ten years of operation. Our numerical modeling-based sensitivity analysis of operational conditions identifies the specific underground conditions as well as drilling configuration (horizontal/vertical) as the most influencing parameters. With about 90% of the investigated reservoirs in the URG transferable into HT-ATES, our analyses reveal a large storage potential of these well-explored oil fields. In summary, it points to a total storage capacity in depleted oil reservoirs of approximately 10 TWh a−1, which is a considerable portion of the thermal energy needs in this area.

ANSYS study is conducted for ball bearing thermal performance such as temperature distribution, total heat flux and directional heat flux for maintain the recrystallization temperature. Because if the temperature continuously increases means it affects the various parameters such as oil viscocity, increases the friction at mating parts and catastrophic machinery failure occurs. In our project we make a design and analysis of the ball bearing with three different materials. Presently the bearing are made by the material of stainless steel, this project we are testing the same load under high chrome and metal matrix materials to determine mkthe thermal performance. If temperature increases means oil viscocity will decreases drastically then the lubrication between the mating parts will become very poor and there is no result in heat reduction. Excess heat could decreases the effectiveness of the lubricating oil and it separate from the thickness. The temperature acting on the inner surface of the bearing is applied and analysis is carried out by using ansys software and determine the total heat flux with directional heat flux.

European Building Codes have transitioned towards Net Zero Energy Building (NZEB) requirements in new constructions, demanding high levels of insulation and airtightness derived from research and standards developed in Northern and Central Europe. The use of these principles in Southern Europe, where solar radiation is greater and building typologies and user behaviour are different, may have had a negative impact in Thermal Comfort and Energy Demand and Consumption. In this study, six dwellings located in a 2018 27-storey Passivhaus-certified building were monitored for a period of 9&ndash, 18 months in 2019 and 2020. In the spirit of a complete Post-Occupancy Evaluation, a User Comfort Survey was carried out. The obtained data were analysed and fixed-limit and adaptative comfort models were used to assess the compliance of several European Comfort Standards, namely, EN ISO 7730, EN 15251, CIBSE TM:52, CIBSE TM:59 and CIBSE Guide A. Experimental results confirmed the issues reported by occupants in the Comfort Survey, making evident a severe overheating problem which we were able to quantify. In addition to presenting the obtained data and its analysis, this paper discusses the plausible causes and health-related implications of excess heat in NZEB Housing in the Northern Spanish climate.

District heating (DH) is an important technology in future smart energy systems as it allows for an efficient implementation of various renewable energy sources. As DH develops towards lower temperatures and renewable electricity production increases, new types of heat sources become relevant. Thus, the aim of this article is to assess the potential for utilizing four unconventional excess heat (UEH) sources in DH systems, namely: Data centers, wastewater treatment, metros and service sector buildings. The main method used to assess the UEH potentials is an energy system analysis focusing on the availability and economic feasibility of utilizing the UEH sources in national contexts. The analysis consists of 2015 and 2050 scenarios for Germany, Spain and France. The results show a potential for utilizing the UEH potentials in all three countries, both in 2015 and 2050 systems. The potentials are highest in the 2050 scenarios, primarily due to larger DH shares. Furthermore, the potentials are limited by competition with other heat supply sources, conjunction with heat demands and feasible heat pump operation. In conclusion, the four UEH sources could impact the local DH systems, but in a national energy system context they are expected to play a minor role.

© 2020 Elsevier Ltd Myanmar's territory mostly experiences tropical monsoon climate, where temperatures are normally not extreme, but humidity can increase discomfort. In response, vernacular architecture strategies have evolved to deal with excess heat and humidity. One of the most prominent of these strategies is the use of high multistage roofs with ventilation. Over the years, many of the traditional buildings were altered but the use of multistage roof design has remained remarkably resilient in Myanmar. Nevertheless, little is known about their contribution to thermal comfort and their vulnerability to overheating risks due to the pervasive threat of the climate crisis. In the work presented here, a thorough review of multistage roof typologies was followed by an investigation of their performance when building parameters including form, ventilation and materials were varied. Twenty-four dynamic simulations were performed using three building typologies and thirty-two computational fluid dynamic simulations were performed using two building typologies. In all cases, indoor volumes were kept the same. The results suggest that with the use of a typical light-weight permeable envelope, the indoor temperatures follow outdoor ambient temperature closely; although a heavier-weight set of materials did not impact significantly on the maximum air temperatures, it has made a different with regard to the lowest temperatures and overall comfort. The variable that impacted the most on the results was roof ventilation mode, with the best results being 3.5 % of a year better than the worst. The multistage roof was found to help reduce heat gains form solar radiation. The findings showed that Myanmar's vernacular buildings with multistage roofs offer an opportunity to improve indoor comfort in tropical climates and therefore its ability to moderate indoor temperatures through the use of simple building physics and geometry should be honoured.

A new set of underwear and protective clothing with phase change materials (PCM) for mine rescuers has been developed in order to increase their safety of work. It includes PCM pouches absorbing excess heat from the body. In order to evaluate thermal load of mine rescuers, physiological tests were carried out for three variants of possible use of the developed set of clothing: for mine rescuers wearing only the underwear with PCM, for a set of underwear and protective clothing, and for a complete set of clothing with closed-circuit compressed oxygen breathing apparatus. Tests were performed in difficult microclimate conditions, reflecting the typical working conditions of rescuers that cause a significant thermal load. The use of outer clothing shortened safe time of exposure to such conditions by about 36%, while the addition of respiratory protective device to this set further shortened this time to a lesser extent (by another 13%).

Urban waste heat recovery, in which low temperature heat from urban sources is recovered for use in a district heat network, has a great deal of potential in helping to achieve 2050 climate goals. For example, heat from data centres, metro systems, public sector buildings and waste water treatment plants could be used to supply 10% of Europe’s heat demand. Despite this, at present, urban waste heat recovery is not widespread and is an immature technology. Based on interviews with urban waste heat stakeholders, investors interested in green investments, and experience from demonstrator projects, a number of recommendations are made. It is suggested that policy raising awareness of waste heat recovery, encouraging investment and creating a legal framework should be implemented. It is also recommended that pilot projects should be promoted to help demonstrate technical and economic feasibility. A pilot credit facility is suggested aimed at bridging the gap between potential investors and heat recovery projects.

It is now known that cold fusion effects are produced mainly by certain palladium materials made under special conditions. Most palladium materials do not produce any excess heat, and no helium production is observed. The palladium used in our first 6 months of cold fusion experiments in 1989 at the China Lake Navy laboratory never produced any measurable cold fusion effects. Therefore, our first China Lake results were listed with CalTech, MIT, Harwell, and other groups reporting no excess heat effects in the DOE-ERAB report issued in November 1989. However, later research using special palladium made by Johnson-Matthey produced excess heat in every China Lake D2O-LiOD electrolysis experiment. Further experiments showed a correlation of excess heat with helium-4 production. Two additional sets of experiments over several years at China Lake verified these measurements. This correlation of excess heat and helium-4 production has now been verified by cold fusion studies at several other laboratories. Theoretical calculations using a new equation show that the amounts of helium-4 appearing in the electrolysis gas stream are in the parts-per-billion (ppb) range. The experimental amounts of helium-4 in our experiments gave reasonable agreement with the theoretical amounts. The helium-4 detection limit of 1 ppm (1000 ppb) reported by CalTech and MIT was far too insensitive for such measurements. Unusually large excess powers leading to the boiling of the electrolyte would be required in electrochemical cold fusion experiments to even reach a detection limit of 1000 ppb helium-4 in the electrolysis gas stream.

Data centres (DCs) are expected to satisfy the rising demand for internet services. Denmark alone is expected to host several large-scale DCs, whose demand for electricity in 2040 may reach 33% of 2017 national electricity consumption. Understanding the operation and interactions of DCs with energy systems is key to understanding their impacts on installed capacities, costs and emissions. The present paper makes three contributions in this regard. First, we introduce a thermodynamic model that relates the power consumption of DCs to their production of excess heat (EH). Second, the results are scaled up to represent DCs in a national energy-system model for the analysis of different scenarios. Third, scenarios are generated and analysed to quantify the impact of DCs on the Danish energy system until 2050. The results show that DCs might have significant impacts on Denmark’s power and district heating (DH) sectors. First, the power demand from DCs translates into an additional 3–6 GW of offshore wind capacity. Second, EH from DCs is beneficial to the whole energy system, the entire quantity of EH being utilized in four out of five scenarios. EH recovery from DCs is economically beneficial, providing from 4% to 27% of Denmark’s DH after 2040.

Industrial Excess Heat (IEH) is an underutilised resource which could contribute to decarbonising the heat supply. It is particularly well suited for supplying district heat networks (DHN), thereby enabling the capture and distribution of excess energy from industries and incineration plants. However, as heat cannot be readily transported over long distances, there is a need to analyse the balance of supply and demand over time taking into account the geospatial constraints placed on the linking of IEH supplies and DHN demands. This work presents an analysis of the potential for the supply of DHN systems using high and low network temperatures by IEH in Switzerland. A spatial clustering method is used to link potential supplies and demands, and monthly supply and demand curves are used to calculate the potential for IEH supply subject to spatiotemporal constraints. A further analysis deals with the technical potential for seasonal storage to shift surplus IEH energy from summer to winter. A total resource of 12TWh/y of IEH was found, but spatial and temporal constraints limited its utilisation to between 7.7TWh/y and 10.5TWh/y depending the scenario considered. 17.4% of total heat demand could be supplied by IEH using low temperature DHN and seasonal storage.

Large-scale heat pumps (HPs), biomass CHPs and excess heat (EH) from industry and data centres are promising district heating (DH) sources. Electricity and thus power transformers (PTs) will be an important part of the future energy system, which opens the possibility to use the thermal losses occurring in PTs for DH. The present paper analyses high voltage PTs in Denmark as DH sources. First, we employ a thermodynamic model of PTs to determine the EH they produce. Subsequently, we analyse thermodynamic properties of heat exchangers and HPs necessary to utilise EH for DH. Finally, we perform a GIS analysis to link the PTs with specific DH networks. From the theoretical amount of excess heat from power transformers (EHPT) available for DH of 0.28 TWh per year, 0.12 TWh or 0.5% of Danish DH demand can reach the consumers. 0.07-0.21 GWh can reach the consumers below the average DH price. The entire EHPT potential can be utilised through HPs, working with an average COP of 4. The sensitivity analysis showed that the EHPT can supply up to 2.26% of the Danish DH demand. Therefore, EHPT is a relatively small DH source on the national scale but could be an important local option.

The coupling parameter series expansion (CPSE) is used to calculate coefficients a i ( i = 1,2,3,…7) of the high temperature series expansion (HTSE) for two hard sphere ＋ square well models and two hard sphere ＋ square well ＋ square shoulder models, the four sets of coefficients are used to construct 28 Pade approximant variants P n ∕ d for the four models. Based on the 28 Pade variants, six common thermodynamic functions for the four models are calculated and compared with corresponding results based on MC simulations reported in the literature and the HTSE truncated to seventh order in the present work, respectively. Several conclusions are generalized from the comparisons: (i) the commonly used rule of the minimum value for n − d to choose the best Pade approximation may not select the best one, which depends on the model and relevant parameters values and has to be determined in advance by reference to simulations. (ii) From the whole table of 28 Pade approximants, reliable (throughout the text, by “reliable” we mean the results are at least qualitatively correct) variants always can be singled out, which not only provides an improvement over the raw HTSE truncated at the optimal order but also is free of pole(s) and consequently applicable over reasonably wide phase space of interest; particularly, the improvement can be immense for most but not all of the models considered when the excess heat capacity is being considered. (iii) Among the reliable P n ∕ d approximations picked, some have high values of n + d indicating that the higher-order HTSE coefficients calculated by the CPSE provide important and reliable information for the unknown excess Helmholtz free energy, and the conventional Pade summation indeed provides an effective method to utilize the information. (iv) The Pade summation can be a resort in statistical mechanics perturbation theories of simple potential fluids because of its simplicity in the actual application and possibility in improving the raw HTSE; however, to ensure the use reliably, one comprehensive pre-research should be carried out.

This research aims to examine changes in heat waves (HWs) over Chile from 1961 to 2016 using daily maximum (TX) and minimum temperature (TN) data recorded at 13 weather stations. Based on three HW-definitions and five aspects for each definition some 15 indices were calculated and analyzed for the extended summer period (November-March). The three definitions of the HWs employed in this study were based on: (1) the TX exceeding the 90th percentile for at least three consecutive days, (2) the TN exceeding the 90th percentile for at least three consecutive days, and (3) the positive values of excess heat factor (EHF) maintaining for at least three consecutive days. The five aspects calculated for each of the definitions provided information related to the frequency, duration, and intensity of HWs. Trends (be them increasing or decreasing), magnitude (change per decade) and statistical significance (p

To achieve climate goals, the iron and steel industry needs to find energy efficient and cost saving pathways for implementing CO2 capture. This paper evaluates two integration alternatives of excess-heat powered CO2 capture at an integrated iron and steel plant using the concept of partial capture. The two sources of CO2 investigated were the blast furnace gas (BFG) and flue gas from the combined heat and power (CHP) plant, representing a high and low level integration alternative, respectively. An amine capture system was simulated in Aspen Plus, and optimized for low energy requirement. To analyze the effects on the iron and steel system and the level of available excess heat, an in-house model was used containing interlinked energy and mass balances of each process step available. The results show that high level integration of CO2 capture gives a lower specific heat demand and improves the overall energy efficiency of the steel plant, resulting in more available heat. For this reason, it is possible to capture 3% more from BFG without any extensive alterations to the plant to recover excess heat. The total available excess heat at the plant will sustain capture of up to 46% of the steel plants total CO2 emissions, and beyond that point steam has to be imported.

The paper analyses the possibilities to recover excess heat from CO 2 supermarket refrigeration plants for supply to district heating networks. It was analyzed to operate the refrigeration system at an increased gascooler pressure to directly supply heat and to install a cascade heat pump to recover the heat from lower temperatures. Increasing the gascooler pressure appeared promising during summer, while the cascade heat pump showed higher COPs during colder periods. The investment for the cascade heat pump could be compensated within 4 years at district heating prices above 37 €/MWh.

Anomalous heat effect by interaction of hydrogen isotope gas and metal nanocomposites supported by zirconia or by silica has been examined. Observed absorption and heat evolution at RT were not too large to be explained by some chemical processes. At elevated temperatures of 200–300 °C, most samples with binary metal nanocomposites produced excess power of 3–24 W lasting for up to several weeks. The excess power was observed not only in the D-Pd·Ni system but also in the H Pd·Ni system and H Cu·Ni system, while single-element nanoparticle samples produced no excess power. The Pd/Ni ratio is one of the keys to increase the excess power. The maximum phase-averaged excess heat energy exceeded 270 keV/D, and the integrated excess heat energy reached 100 MJ/mol-M or 90 MJ/mol-H. It is impossible to attribute the excess heat energy to any chemical reaction; it is possibly due to radiation-free nuclear process.

The low-temperature heat capacity of (U 1-y ,Am y )O 2− x solid solution with y = 0.0811 and 0.2005 and x = 0.01–0.03 was determined from a minimum of 12.52 K up to 297.1 K and from 9.77 K up to 302.3 K, respectively, using hybrid adiabatic relaxation calorimtry. The low temperature heat capacity results of the investigated system revealed the absence of the magnetic transition specific for UO 2 in the temperature region of 30 K. Since there are no experimental data available for AmO 2 in this temperature region, the results obtained for the intermediate compositions are validated based on the experimental data of UO 2 end-member and the low-temperature heat capacity computation of AmO 2 . In the measured temperature interval, excess heat capacity was observed for the two investigated intermediate compositions, which is concluded to be dominated by self-radiation effects at very low temperature.

The recovery of industrial excess heat for use in district heating systems can be characterised by great political interest, high potential, low utilisation and often high profitability. These char ...

In this study, excess molar enthalpies, H123E and molar heat capacities, (CP)123 of ternary [Bmim][BF4] (1) + [Emim][BF4] (2) + cyclopentanone or cyclohexanone (3) mixtures (as a potential solvent system for heat transfer processes) have been measured over the entire range of composition. The (CP)123 and H123E measurements have been carried out over temperature range 293.15 K to 308.15 K with 5 K interval and 298.15 K respectively. The observed (CP)123 data have been utilized to determine excess heat capacities, (CPE)123. While H123Evalues for investigated mixtures are negative, (CPE)123 are positive over entire mole fraction range of (1) and (2) components. The H123E and (CPE)123 data of the present mixtures have also been tested in terms of Graph theory. It has been observed that H123E and (CPE)123 values calculated by Graph theory are in comparison with the experimental data.

Industrial excess heat may often be utilised for district heating and thus replace existing expensive or CO2-emitting technologies. Previous works analysed the distribution of excess heat by temperature intervals and their geographical distribution relative to district heating areas. A more detailed analysis of the most suitable types of industries and the costs is required, allowing a targeted exploitation of this resource. This work extends the spatial and thermodynamic analysis, to account for the temporal match between industrial excess heat and district heating demands, as well as the costs for implementation and operation of the systems. This allows the determination of cost-effective district heating potentials, as well as the analysis of different industries and technological requirements. The results show that the temporal mismatch between excess heat and district heating demand and lack of demand, reduces the theoretical substitution potential by almost 30%. If heat storages are introduced, the total potential is reduced by only 10%. A majority of the excess heat can be utilised at socio-economic heating costs lower than the average Danish district heating price and the cost of solar district heating. Excess heat from oil refineries, building material and food production can be utilised at the lowest specific costs.

In the present investigations, the excess molar volumes, $$ V_{ijk}^{\text{E}} $$ , excess isentropic compressibilities, $$ \left( {\kappa_{S}^{\text{E}} } \right)_{ijk} $$ , and excess heat capacities, $$ \left( {C_{p}^{\text{E}} } \right)_{ijk} $$ , for ternary 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (i) + 1-butyl-3-methylimidazolium tetrafluoroborate (j) + 1-ethyl-3-methylimidazolium tetrafluoroborate (k) mixture at (293.15, 298.15, 303.15 and 308.15) K and excess molar enthalpies, $$ \left( {H^{\text{E}} } \right)_{ijk} $$ , of the same mixture at 298.15 K have been determined over entire composition range of x i and x j . Satisfactorily corrections for the excess properties $$ V_{ijk}^{\text{E}} $$ , $$ \left( {\kappa_{S}^{\text{E}} } \right)_{ijk} $$ , $$ \left( {H^{\text{E}} } \right)_{ijk} $$ and $$ \left( {C_{p}^{\text{E}} } \right)_{ijk} $$ have been obtained by fitting with the Redlich–Kister equation, and ternary adjustable parameters along with standard errors have also been estimated. The $$ V_{ijk}^{\text{E}} $$ , $$ \left( {\kappa_{S}^{\text{E}} } \right)_{ijk} $$ , $$ \left( {H^{\text{E}} } \right)_{ijk} $$ and $$ \left( {C_{p}^{\text{E}} } \right)_{ijk} $$ data have been further analyzed in terms of Graph Theory that deals with the topology of the molecules. It has also been observed that Graph Theory describes well $$ V_{ijk}^{\text{E}} $$ , $$ \left( {\kappa_{S}^{\text{E}} } \right)_{ijk} $$ , $$ \left( {H^{\text{E}} } \right)_{ijk} $$ and $$ \left( {C_{p}^{\text{E}} } \right)_{ijk} $$ values of the ternary mixture comprised of ionic liquids.

An experimental study of evaporating meniscus instability was performed for five capillary tube diameters ranging from 0.3 to 1.2 mm and three different volatile fluids ( n -pentane, ethanol and acetone). By heating the tubes above the meniscus, the meniscus was observed to destabilize, unless the capillary tube suffered a mechanical failure due to the excess heat load. The onset of instability was recorded as a meniscus height measurement. The temperature difference across the meniscus, or superheat, at the onset of instability was calculated using the measured height and a previously validated mathematical model. Of the menisci destabilized, the superheat values varied non-linearly with capillary tube diameter. The smaller capillary tubes required higher superheats for instability. Comparison of the calculated superheats with previously developed stability criteria proved unsuccessful. An empirical relation was observed when the instability heights were scaled by the capillary geometry. Additional comparison was drawn between the capillary tubes and channels, and it was found that tubes require a larger superheat to destabilize as compared to a channel of comparable geometry.

In the present study, molar heat capacities, $$\left( {C_{\text{P}}^{{}} } \right)_{123}$$ , at T/K = 293.15–308.15 K with 5 K interval and excess molar enthalpies, $$H_{ 1 2 3}^{\text{E}}$$ , at T/K = 308.15 for ternary tetrahydropyran (1) + piperidine (2) + cyclohexanone or cycloheptanone (3) and molar heat capacities, $$(C_{\text{P}}^{{}} )_{12}$$ , for binary tetrahydropyran (1) + piperidine (2) mixture at T/K = 293.15, 298.15, 303.15 and 308.15 have been determined as a function of composition using microdifferential scanning calorimeter. The $$\left( {C_{\text{P}}^{\text{E}} } \right)_{123}$$ , $$H_{123}^{\text{E}}$$ and $$(C_{\text{P}}^{\text{E}} )_{12}$$ data have been fitted to Redlich–Kister equation to predict ternary and binary adjustable parameters along with standard deviation in the measured properties. The observed $$\left( {C_{\text{P}}^{\text{E}} } \right)_{123}$$ , $$H_{123}^{\text{E}}$$ data have been tested in terms of graph theory which in turns deals with the topology of the constituent molecules. It has been observed that $$\left( {C_{\text{P}}^{\text{E}} } \right)_{123}$$ and $$H_{123}^{\text{E}}$$ values estimated by graph theory are comparable with the experimental data.

This paper quantifies experimentally the flame radiation fraction of facade fire ejected from opening of a compartment, which has not been quantified in the past. However, its value is essential for estimating the radiation impact to surroundings. A series of experiments were conducted by employing a cubic compartment with an opening attached by a vertical facade wall. The radiation heat flux under different compartment ventilation conditions (opening sizes) was measured by a radiometer placed at side direction (parallel to the facade wall). A new calculation method on flame radiation fraction of facade fire was proposed and it was found that the flame radiation fraction decreases with increasing excess heat release rate outside the opening. A non-dimensional correlation was proposed to describe its evolution for openings of various dimensions. The new findings and the proposed non-dimensional correlation provide a fundamental base for understanding essentially the flame radiation fraction of facade fire ejected from the opening of a fire compartment.

This article investigates possibilities for including prosumer structures in heating networks. Therefore, the performance of three different heating system scenarios for a new housing district is investigated. Low (60 °C) and ultra-low (20 °C) network temperatures are investigated. The case study includes about 100 different single-family and multi-family houses. Two scenarios contain networks with temperatures of 20 and 60 °C. The third scenario is extended with solar collectors and a supermarket as decentralised prosumers who supply heat to the network in times of surplus. The network can simulate bidirectional flows. Based on the principles of graph theory, a combined hydraulic and thermal model is developed and used for this study. The results show a heat loss reduction in ultra-low temperature networks due to lower network working temperatures (20 °C) of about 80% compared to a low-temperature network. The implementation of prosumers considerably reduces the demand from a central heat source. In this study, 20% of the total heating demand can be covered by excess heat of the prosumer supply.

In this work, the performance of an amine-based post-combustion carbon capture system using MEA (monoethanolamine) integrated to a Waste-to-Energy (WtE) plant is studied. WtE plants are affected by fluctuations at different time-scales, due to changes in waste properties as well as variations in district heat demand. A dynamic model of the combined plant is used to study the effect of flue gas fluctuations on capture plant operation, and the effect of integrating the capture plant into the WtE plant. When the two plants are considered separately, the heat requirement of the capture plant corresponds to 27% of the nominal thermal capacity of the WtE plant. When integrating the two plants, steam extraction from the boiler drum to provide the heat necessary to the capture plant reduces the power and district heat production of the WtE plant by 30% and 6% respectively, while extraction from the turbine causes a reduction of 8% and 12%. By modifying the condensers’ temperature, it is possible to maintain 96% of the original district heat production. By performing carbon capture only when excess heat is available, it is possible to capture 47% of the CO2 emitted by the WtE plant, while reducing the power production by only 5%.

Effect of Phase Change Material (PCM) on electrical efficiency and operating temperature of PV panel is studied in this article. PCM is filled in rotatable shutters attached to the back side of PV panel. PCM filled rotatable shutters are used to ensure the complete solidification of PCM during non-sunshine hours. During sunshine hours PCM filled shutters are closed and absorb excess heat generated by PV panel. The absorbed heat is discharged by rotating the PCM filled shutters to ambient during non-sunshine hours. The modeling results revealed that conventional PV panel temperature without PCM can be as high as 64 °C that can be reduced to 42 °C using PCM filled shutters with melting temperature of 35 °C. Efficiency can be improved up to 9% during peak summer season for the PV panel working under hot humid climatic conditions. Maximum benefits of PCM in terms of temperature reduction and are observed during the summer season compared to the winter season. The study also suggested that states if the PCM melting temperature is approximately equal to the average of the maximum ambient temperature of all summer months, then maximum benefits in terms of efficiency improvement and temperature reduction can be achieved for the whole year.

In this paper, molar heat capacities (C P)123 data of 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, [Bmmim][BF4] (1) + 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF4] or 1-ethyl-3-methylimidazolium tetrafluoroborate, [Emim][BF4] (2) + cyclopentanone or cyclohexanone (3) mixtures have been reported over the entire range of composition at (293.15, 298.15, 303.15, 308.15) K using micro-differential scanning calorimeter (Model—μDSC 7 Evo). The results have been utilized to calculate excess heat capacities $$ \left( {C_{\text{P}}^{\text{E}} } \right)_{123} $$ values of the studied mixtures. The $$ \left( {C_{\text{P}}^{\text{E}} } \right)_{123} $$ data have been fitted to Redlich–Kister equation to obtain ternary coefficients and standard deviations. The Moelwyn–Huggins concept of interaction between the surfaces of constituents of binary mixtures (Huggins in J Phys Chem 74:371–378, 1970) containing ionic liquid as one of the component has been extended to obtain expression (Graph theory) for $$ \left( {C_{\text{P}}^{\text{E}} } \right)_{123} $$ of ternary mixtures. The comparison between experimental and estimated values (Graph theory) suggests that while 1-butyl-2,3-dimethylimidazolium tetrafluoroborate or 1-butyl-3-methylimidazolium tetrafluoroborate or 1-ethyl-3-methylimidazolium tetrafluoroborate exists as monomer, cyclopentanone or cyclohexanone exists as mixture of open and cyclic dimer. The results further support the various processes involved in the formation of present mixtures. The $$ \left( {C_{\text{P}}^{\text{E}} } \right)_{123} $$ values have also been tested in term of modified Flory’s theory.

The excess molar enthalpies, $$H^{\text{E}}$$ , of piperidine (1) + cyclopentanone or cyclohexanone or cycloheptanone (2) at 308.15 K and densities, ρ, speeds of sound, u, and molar heat capacities, $$C_{\text{P}}^{{}}$$ , of the same set of the mixtures have been measured as a function of composition at temperatures from 293.15 to 308.15 K. The measured ρ, u, and $$C_{\text{P}}^{{}}$$ data have been employed to determine excess molar volumes, $$V^{\text{E}}$$ , excess isentropic compressibilities, $$\kappa_{\text{S}}^{\text{E}}$$ , and excess heat capacities, $$C_{\text{P}}^{\text{E}}$$ . The thermodynamic properties have been fitted to Redlich–Kister equation to compute binary adjustable parameters and their standard deviations. The results have been analyzed in terms of Graph theory (which deals with the topology of the molecule) to correctly predict (1) state of the components in pure and mixed states, (2) to understand the nature and extent of molecular interactions existing in their mixtures, (3) $$V^{\text{E}}$$ , $$\kappa_{\text{S}}^{\text{E}}$$ , $$H^{\text{E}}$$ , and $$C_{\text{P}}^{\text{E}}$$ values. The analysis of $$V^{\text{E}}$$ data in terms of Graph theory suggests that while piperidine is characterized by hydrogen bonding and exists as associated molecular entity, cyclopentanone, cyclohexanone, and cycloheptanone exist as mixture of open and cyclic dimers. The estimated inter-nuclear distances among the interacting atoms using quantum mechanical calculations also support the existence of proposed molecular entities in pure and mixed states. It has been found that $$V^{\text{E}}$$ , $$\kappa_{\text{S}}^{\text{E}}$$ , $$H^{\text{E}}$$ and $$C_{\text{P}}^{\text{E}}$$ data predicted by Graph theory compare well with the their experimental data. The IR studies also support this view point.

The asymmetrical Double-sided Friction Stir Welding (DFSW) technique was applied to the fine-grained non-combustive AMX602 (Mg-6%Al-0.5%Mn-2%Ca) magnesium alloy in order to tailor the appropriate crystallographic texture in the joint and maintain its mechanical properties. The diverse material flows caused by the different welding parameters affected the macrostructure of the DFSW joints. As the travel speed increased, the larger flash and the internal cavity disappeared, and the prior interface residue composed by a linear array of Ca oxide and adjacent coarse grains with lacking of Ca solute, which is a kind of joint defect due to excess heat input, became shorter. The complicated material flows caused by the asymmetrical layout of the double-sided tools produced a relatively weaker texture in the DFSW joint. In addition, compared with the one-sided FSW joint, the asymmetrical DFSW joint shows a relative higher strength since the microstructure in the joints maintains a fine grained structure with slight crystallographic isotropy.

The densities, ρ , speeds of sound, u , and molar heat capacities, C P , of 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (1) + cyclopentanone or cyclohexanone (2) mixtures at 293.15, 298.15,303.15 and 308.15 K and excess molar enthalpies, H E of same mixtures at 298.15 K have been measured as a function of composition. The observed ρ , u , and C P values are used to determine excess molar volumes, V E , excess isentropic compressibilities, κ S E and excess heat capacities, C P E . The analysis of V E data in terms of Graph theory has suggested that while 1-butyl-2,3-dimethylimidazolium tetrafluoroborate exists as monomer; cyclopentanone and cyclohexanone exist as mixture of open and cyclic dimer. The analysis of inter-nuclear distances among interacting atoms (predicted by quantum mechanical calculations) also supports the presence of proposed molecular entities in pure and mixed states. It has been observed that V E , κ S E , C P E and H E estimated by Graph theory compare well with their experimental values.