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As the most widely used power semiconductor devices, insulated gate bipolar transistor (IGBT) modules are normally composed of parallel IGBT chips to achieve the desired current capability. However, the electro-thermal behavior of each chip is significantly different due to the asymmetric layout, increasing the overheating risk of single chip. Therefore, this paper proposes a novel approach to describe the thermal safe operation area (TSOA) of multichip IGBT modules in the inverter application, considering the uneven temperature distribution among parallel chips. The novelty of the approach is that it applied the proposed analytical model describing the uneven electro-thermal behavior, thus avoiding the traditional averaging process. Comprehensive investigation has been made to reveal the deep mechanism of the inconsistent temperature distribution, which are the uneven dynamic current sharing and thermal cross-coupling effects. Correspondingly, the analytical model of the uneven switching loss and the standard form of thermal resistance matrix related to cooling performance, are proposed and further verified, respectively. Based on the proposed approach, the recommended operation area of different rated devices is fully described. The contribution of this paper enables more well-founded device selection to achieve a safe and cost-efficient design for the inverter application.

The objective of the paper is to evaluate the Engine cooling performance of the light commercial vehicle by data acquisition. The data acquisition is done following Indian standard, IS: 14557:1998. Sometimes, the ambient temperature conditions and actual vehicle parameters may differ, then as mentioned in standard, thus making it necessary to go beyond standard conditions. The methodology of testing is to acquire data and compare the thermal behaviour in five different vehicle configurations. In the first case, a subjected vehicle was operated with a conventional fixed fan that is permanently engaged and a smaller radiator, which more or less resulted in overheating of the vehicle. Then in the second case, data is acquired with a viscous fan, bigger core radiator, fresh air cleaner. The viscous fan operates only when the coolant temperature goes beyond a specified limit. It gives a better cooling performance, lower cabin noise, and higher fuel efficiencies. In the third case, a fresh air cleaner is replaced with a clogged air cleaner, to simulate extreme dusty, off-road conditions like mining, where power and torque demand is maximum and the vehicle operates at lower vehicle speeds. In the fourth and fifth cases, experiments were conducted to check the actual performance of the vehicle on plain roads and hilly routes for a better driving simulation. The specific finding of the paper is that a vehicle may clear the cooling performance according to the standard requirements, but it may fail in the actual field conditions. So, a factor of safety must be considered while designing an engine cooling system, which makes it fit for worse field applications. Finally, the gathered data is used to upgrade the engine cooling management system.

The degradation of the electrical contact in a gas insulated switchgear (GIS) is closely related to overheating at the contact. However, the disconnector contact is one of the hot contacts in GIS. Therefore, in this paper, the finite element method was used to solve the three-dimensional multiphysics coupling temperature rise field and flow field in the Single Phase in One Tank (SPIOT) type GIS disconnector under different operating conditions. From the perspective of temperature rise field and flow field, this paper analyzed the temperature rise characteristics under different working conditions and explored the feasibility of the direct application of air, CO2 and C4F7N/CO2 mixed gas to an electrical device. The disconnector temperature rise experiment platform was then built to verify the simulation. The results showed that the temperature rise field and the flow field distribution were similar in four gas environments. SF6 gas had the smallest temperature rise, followed by C4F7N/CO2 mixed gas, and the temperature rise of CO2 and air was relatively large. Therefore, from the perspective of the temperature rise field and flow field, it was feasible to directly apply C4F7N/CO2 mixed gas to an electrical device in order to meet insulation requirements.

Solar greenhouses are currently the most energy-intensive agricultural sector. In literature, there is no worldwide mapping of solar greenhouse performance under different climate scenarios. This study analyzes the performance of a Venlo solar greenhouse for 48 localities around the world. Solar greenhouses are mainly made of a transparent envelope and the effect of the direct and diffuse component of solar radiation impacts the internal plant well-being. This study aims to identify the best solution of a transparent envelope on locations with different latitudes and evenly distributed around the globe. The simulations are carried out using TRNsys, considering different thermal phenomena three-dimensional shortwave and longwave radiative exchange, airflow exchanges, presence of lamps with their exact 3D position, ground, plant evapotranspiration, and convective heat transfer coefficients. A total of 336 simulations are performed in the free-floating regime. A new index for the identification of the best glass solutions based on annual average deviation is defined. For all climates, the best glass solutions work better in winter than in summer. The optimal choice of the glass must be combined with effective scheduling of openings for natural ventilation to avoid internal overheating phenomena.

This work presents the steps for validating a new topology of magnetic coupling with direct application in automotive water pumps. Starting from analytical studies, a model in two dimensions for simulation by finite elements was created, whose effectiveness was proven with the performance measured by the construction of a prototype. Based on the eddy current coupling technology, the amount of power transferred can be adjusted according to the desired engine operating temperature. This technology consumes less electrical current in comparison with a motor-driven water pump since the primary pumping power source is the combustion engine. Another advantage is the residual torque operating mode that uses the magnetism generated by permanent magnets in the absence of electrical power, which is an important function to protect the engine against overheating in the case of an electrical failure. The results presented here validate the concept regarding the controllability of the device and highlight points to improve the machine’s performance, thus facilitating new developments and future work.

Sunlight Concentrated and transmission for daylighting via optical fibers is a booming technology of direct utilization of solar energy. It uses optical fibers to introduce sunlight deep into building interior. In this work, a sunlight concentrating and transmitting system via plastic optical fibers was developed and tested. This study addressed the cooling problem of the plastic optical fibers under highly irradiation. Polymethylmethacrylate (PMMA) plastic fibers have a strong absorption effect on infrared light, which means that plastic fibers heat up so much when they transmit focused sunlight that they burn. In this study, a comprehensive cooling approach was developed to solve the overheating problem of plastic optical fibers, which consists of an infrared filter, cooling water and a homogenizer. The transmission efficiency of the system was measured to be about 15%. Experiments show that the comprehensive cooling measures developed can ensure that PMMA plastic optical fibers are in a safe temperature range. This shows that it is feasible to use low-cost plastic optical fibers instead of expensive silica fiber to transmit high flux for daylighting.

In countries, such as Korea, where climate change is clear due to the four seasons, some of the collected energy must be released in the summer season, and these measures for heat dissipation fail to be very effective, thus causing system overload and defects frequently. In this study, we devised an overheating prevention system for the solar hot water and heating system using the variation of the shadow caused by the solar altitude angle that changes every hour, and for this purpose, a solar power generation module was placed over the solar collector. By using simulations, the system was designed in such a way that direct sunlight would be naturally blocked from reaching the solar collector due to the high solar altitude in the summer and that 100% of direct sunlight could reach the collector due to the low solar altitude in the winter. It was confirmed that the designed conditions were also satisfied in the actual test bed. In order to predict the performance of the system through simulations, the temperature of the solar thermal storage tank was calculated every hour after modifying the energy equation used in a previous study, and as a result of determining whether the system is overheated afterwards, it is expected that the degree of system overheating can be reduced. The shading did not affect the system efficiency in the season in which an actual heating and hot water load was needed.

The goal of this research is to investigate the effect of utilizing selective liquids as absorption filters to prevent PV module overheating by blocking the undesirable part of the spectrum (long wavelength) while allowing the beneficial part of the spectrum (visible light and near infrared) to pass through. The fluids were evaluated on two different panels, and their results were compared to those of a control panel. In this work, two liquids were used and tested: copper sulfate solution (CuSO4·5H2O) and distilled water as absorption filter; each was arranged in such a way that it flows evenly over the surface of a PV module through a cavity mounted on the top side of the PV module. In addition, a standard PV panel was employed as a comparison. The average power produced by the PV when pure was used as an optical filter is 31.3%, while it was 11.3% when copper sulfate solution was used compared with base unit. Furthermore, the cooling effect of pure water on the PV was more efficient than that of copper sulfate solution, with an average PV temperature drop of 15% compared with 7.5% when copper sulfate is used compared with the base unit panel’s performance improved by an average of 31.3% when distilled water was used as the absorption filter, compared to the reference panel’s performance, while the copper sulfate solution improved the panel’s performance by an average of 11.3% compared to the reference panel’s performance.

With the innovation of electronics industry and the advancement in 5G technology, the overheating problem has become an urgent obstacle to further realize the high performance and multi-function of electronic devices. Thus, it is essential to develop efficient thermal management materials to realize timely and effective heat dissipation. The thermal management systems based on phase change materials (PCMs) have received extensive attention in recent years. In this work, composite PCMs with a high phase change enthalpy of 149.56 J g−1, multiple phase change characteristics, a high thermal conductivity of 1.28 Wm−1 K−1, and excellent shape stability were fabricated by the means of cross-linked polymer swelling strategy. When the as-prepared composite PCMs were directly attached to the heating plate or served as thermal interface materials (TIMs) to dissipate heat, the temperature of heating plate can be reduced by 5.8 °C and 18.8 °C, respectively, revealing great potential in the thermal management application of electronic devices.

Owing to the impact of global warming, the weather becomes hotter than the past. Responding to the hot–humid climate, the Taiwan government intends to install air-conditioning in classrooms to provide comfort study environment. The thermal management of school buildings is separated into naturally ventilated and air-conditioning seasons based on the strategies of reducing energy use while maintaining thermal comfort. In this paper, the school buildings located in northern and southern Taiwan (Taipei and Kaohsiung) are selected as study objectives to simulate cooling load, thermal comfort, and the natural ventilation potential to discuss the parameters related to building envelope design. Through regression analysis of the 360 simulation cases, the Overall Thermal Transfer Value (OTTV) for Taipei and Kaohsiung are established. Besides, the coefficient of azimuth correction factor and area ratio correction factor are clarified for equivalent ventilation area. Through coupled analysis, the Pareto ranking method is used to obtain numerical solution sets corresponding to the index including OTTV and equivalent ventilation area. Consequently, a school building envelope design criteria for balancing the energy use and thermal comfort is proposed. According to the analysis results and the intersection of OTTV and equivalent ventilation area at Pareto front, it is confirmed that the restriction of the OTTV index is 20 W/m2 in Taipei and Kaohsiung; the equivalent ventilation area which guarantees no overheating risk during natural ventilation season is determined as 9.5 m2 in Taipei and 14.3 m2 in Kaohsiung. Furthermore, the influence level of the parameters is clarified that the area and shading performance of windows make a major influence on sensible cooling load; comparing to external shading, the window insulation performance is considerably less important. Overall, this study seeks the balance between energy use and thermal comfort then provide the efficient strategies at the initial design stage through the proposed criteria.

High temperature superconductors have zero resistance under critical temperature and the HTS tapes have low thermal conductivity. The China Fusion Engineering Test Reactor(CFETR) project requires current leads with current carrying capacity up to 100 kA, making high temperature superconducting current leads the ideal choice. The main work of this paper is the theoretical analysis and optimization design of the 100 kA HTS current lead. Current leads are designed to minimize heat leakage to the cryogenic system and to reduce the mass flow of cooling gas. In this paper, some important design parameters are introduced firstly, and then one dimensional thermal analysis is carried out for the heat exchanger and high temperature superconductor parts. The LOFA time and overheating time of the current lead were calculated through simulation, and it was verified that the design meets the requirements of the project. Finally, the factors that have great influence on the performance of current leads are analyzed. In view of the four influencing factors, which are joint resistance, GHe inlet temperature, hPw and RRR, we respectively produced an optimized design.

During the operation of high-power proton exchange membrane (PEM) fuel cell, huge heat is generated in the chemical reaction, which need be removed by efficient cooling design. To solve the problem of local overheating during PEMFC, a novel multi-input and multi-output (MIMO) cooling flow field is proposed. The maximum temperature, temperature uniformity and pressure drop characteristics of the U-shaped and Z-shaped cooling flow fields with different MIMO channels configurations are researched by computational fluid dynamics (CFD) method. The results demonstrate that comparing with U-shaped cooling flow field, Z-shaped design can provide better temperature distribution with the same MIMO channel configuration. Moreover, the serpentine cooling flow field provides better cooling performance than parallel cooling flow field, but leads to higher pressure loss. Compared to other cases, Z-shaped serpentine MIMO channel presents the best cooling performance, reducing the maximum temperature value to 322.7 K.

Building ventilation accounts for up to 30% of the heat loss in commercial buildings and 25% in industrial buildings. To effectively aid the reduction of energy consumption in the building sector, the development of demand-driven control systems for heating ventilation and air-conditioning (HVAC) is necessary. In countries with temperate climates such as the UK, many buildings depend on natural ventilation strategies such as openable windows, which are useful for reducing overheating prevalence during the summer. The manual opening and adjustment of windows by occupants, particularly during the heating season, can lead to substantial heat loss and consequent energy consumption. This could also result in the unnecessary or over ventilation of the space, or the fresh air is more than what is required to ensure adequate air quality. Furthermore, energy losses build up when windows are left open for extended periods. Hence, it is important to develop control strategies that can detect and recognise the period and amount of window opening in real-time and at the same time adjust the HVAC systems to minimise energy wastage and maintain indoor environment quality and thermal comfort. This paper presents a vision-based deep learning framework for the detection and recognition of manual window operation in buildings. A trained deep learning model is deployed into an artificial intelligence-powered camera. To assess the proposed strategy's capabilities, building energy simulation was used with various operation profiles of the opening of the windows based on various scenarios. Initial experimental tests were conducted within a university lecture room with a south-facing window. Deep learning influenced profile (DLIP) was generated via the framework, which uses real-time window detection and recognition data. The generated DLIP were compared with the actual observations, and the initial detection results showed that the method was capable of identifying windows that were opened and had an average accuracy of 97.29%. The results for the three scenarios showed that the proposed strategy could potentially be used to help adjust the HVAC setpoint or alert the occupants or building managers to prevent unnecessary heating demand. Further developments include enhancing the framework ability to detect multiple window opening types and sizes and the detection accuracy by optimising the model.

There is growing concern that global warming will change the building’s performance pattern in the future. This paper investigates the effects of climate changes on the heating and cooling energy demand, the overall energy performance and the overheating risk of typical residential buildings (existing and refurbished) in the biggest city of the most populated Italian climatic zone, Milan. The widely used morphing methodology was adapted for creating future weather data for different scenarios. Energy performance analysis was carried out using dynamic simulation for the near term (2021–2040)​ and the long term (2081–2099) periods. The results show decreases in heating energy demand up to 30.9%, intense increases in cooling energy demand, up to 255.1% and significant increases of overheating risk up to 155%. In addition, the effect of refurbishment on each parameter is also analysed and reported. The research demonstrates that climate change causes a paradigm shift in the building energy performance, while the magnitude of climate change impact is not equal for different building types, time periods, insulation levels, and future weather scenarios. Therefore, climate change must be considered for future energy performance assessment of buildings.

Turn-to-turn faults between primary windings due to insulation degradation are a major cause of distribution transformer failure, and occur due to high levels of stress such as overloading and overheating. An additional consequence of these faults is an increased voltage on the transformer secondary due to effective change in turns ratio. This paper develops a novel method for early detection of insulation degradation and subsequent inter-turn winding failure by monitoring the transformer secondary voltage. The algorithm is based on a cumulative sum (CUSUM) statistic and compares voltages on neighbouring transformers to flag degrading assets. Results obtained from simulation as well as experimental data show that smart meter measurements can be utilized to achieve very high detection accuracy while keeping costs low. The paper also demonstrates the validity of the algorithm in the presence of measurement noise, residential solar power injection etc.

PurposeAccurate values for infiltration rate are important to reliably estimate heat losses from buildings. Infiltration rate is rarely measured directly, and instead is usually estimated using algorithms or data from fan pressurisation tests. However, there is growing evidence that the commonly used methods for estimating infiltration rate are inaccurate in UK dwellings. Furthermore, most prior research was conducted during the winter season or relies on single measurements in each dwelling. Infiltration rates also affect the likelihood and severity of summertime overheating. The purpose of this work is to measure infiltration rates in summer, to compare this to different infiltration estimation methods, and to quantify the differences.Design/methodology/approachFifteen whole house tracer gas tests were undertaken in the same test house during spring and summer to measure the whole building infiltration rate. Eleven infiltration estimation methods were used to predict infiltration rate, and these were compared to the measured values. Most, but not all, infiltration estimation methods relied on data from fan pressurisation (blower door) tests. A further four tracer gas tests were also done with trickle vents open to allow for comment on indoor air quality, but not compared to infiltration estimation methods.FindingsThe eleven estimation methods predicted infiltration rates between 64 and 208% higher than measured. The ASHRAE Enhanced derived infiltration rate (0.41 ach) was closest to the measured value of 0.25 ach, but still significantly different. The infiltration rate predicted by the “divide-by-20” rule of thumb, which is commonly used in the UK, was second furthest from the measured value at 0.73 ach. Indoor air quality is likely to be unsatisfactory in summer when windows are closed, even if trickle vents are open.Practical implicationsThe findings have implications for those using dynamic thermal modelling to predict summertime overheating who, in the absence of a directly measured value for infiltration rate (i.e. by tracer gas), currently commonly use infiltration estimation methods such as the “divide-by-20” rule. Therefore, infiltration may be overestimated resulting in overheating risk and indoor air quality being incorrectly predicted.Originality/valueDirect measurement of air infiltration rate is rare, especially multiple tests in a single home. Past measurements have invariably focused on the winter heating season. This work is original in that the tracer gas technique used to measure infiltration rate many times in a single dwelling during the summer. This work is also original in that it quantifies both the infiltration rate and its variability, and compares these to values produced by eleven infiltration estimation methods.

The Internet of Things asserts that several applications, such as smart cities or intelligent agriculture, can be based on various embedded systems programmed to do different tasks, by transferring data over a network from sensors to a server, where the information is stored and treated, supporting the decision-making process. In this context, LoRaWAN is an accurate network topology based on a wireless technology called LoRa that is capable of transmitting small data rates at a long range, using low-powered devices, making it ideal for the acquisition of climate variables, such as temperature and relative humidity. Applying this architecture to agriculture buildings can be very useful to guarantee indoor thermal comfort conditions. In this study, this technology is applied to a passive solar system composed by a high thermal inertia wall, defined as Trombe wall, with air vents provided in the massive wall to improve heat transfer by air convection, and an external shading device to avoid overheating during summer and heat losses during winter. It is intended to analyze the possibility to control the interiortemperature of a poultry brooding house given that, in the early stages of life, chickens need accurate climate conditions in order to enhance their growth and reduce their mortality rate. In brief, temperature values acquired by different sensors placed on the Trombe wall travel through a LoRaWAN wireless network and are received by an application that controls the actuators, in this case, the opening and closing of the Trombe wall air vents, while the external shading device is controlled locally.

This paper investigates the behaviour of two popular structural systems subjected to overheating and column removal cases, which may follow fire incidents. A typical 15–storey steel building is designed with two types of structural system framed-tube and moment-resisting frame. The nonlinear behaviour of these structures under different fire scenarios is investigated using OpenSees Software. The results indicate that deflection of heated beams is insignificant below 400 °C but after that, degrading mechanical properties of steel material leads to large deflection and runaway of heated beams at temperatures below 600 °C. Also, heating the beams of structures initially induces large axial forces in the beams due to restraints on thermal expansion. Thermal expansion of heated floors induces large horizontal displacement and consequently causes additional bending moments in the exterior column. So columns reach their elastic limit at the early stages of fire. Columns of the framed-tube system reach their elastic limit at lower temperatures (130 °C) but fail at higher temperatures (380 °C) compared to columns of the moment-resisting frame system (210 °C). In addition, the lower storey and interior columns are more vulnerable to progressive collapse and fail at lower temperatures (330 °C) due to carrying more gravity loads. In most fire scenarios, beams and columns of framed-tube systems fail at higher temperatures and perform well in the fire than moment-resisting frame systems. In column removal scenarios, mid-span displacement of the heated beam increases significantly, leading to downward movement of upper stories. Also, column removal in the framed-tube system is more destructive than in the moment-resisting frame system. In general, in both structural systems, column removal scenarios, which may follow fire, induce more damage to the structures than general temperature rise in considered fire scenarios.

Inadequate cold start capability impedes the diffusion of fuel cell vehicles in cold regions. While the isothermal cell commonly used in literature is valuable in examining failure mechanism, it is not suitable for exploring startup strategy and the associated degradation of polymer electrolyte fuel cells (PEFCs). A model cell capable of simulating the adiabatic thermal boundary conditions of central cells inside the stack is needed. Herein, we design an adiabatic cell as a model for the central cells in PEFC stack. The adiabatic thermal boundary condition is realized by utilizing thermal adjustment boards, thermocouples, and heating plates. The power of heating plates is adjusted by a feedback proportion-integration-differentiation controller in real time. The system is shown to be capable of providing an adiabatic thermal boundary condition with quick response rate and having no risk of overheating in successful starts with two kinds of strategies. This cell can work as a model system for reproducible and well-controlled study of cold start of PEFC stack.

General two-dimensional models were derived and solved numerically for the thermoacoustical convection that is generated in a compressible fluid by rapid heating of one of the vertical enclosing walls. In the cases considered, the left wall temperature is raised rapidly (impulsively or gradually) while the right wall is held at a specified temperature. The top and the bottom walls of the considered enclosure are thermally insulated. The numerical solutions of the full Navier–Stokes equations were obtained by employing a highly accurate flux-corrected transport algorithm for the convection terms and by a central differencing scheme for the viscous and diffusive terms. It is numerically established that the magnitude of the power of pressure waves associated with the thermoacoustic effect, and the resulting flow pattern is strongly influenced by the difference in wall temperatures (values of overheating) and the speed of the wall heating process.

The optimization of the installation characteristics of photovoltaic (PV) generators guarantee greater generation of electric energy and a better distribution of solar irradiation of the PV modules; on the other hand, to determine the sizing factor- SFI, one must take into account the saturation losses of the AC output during conditions of high irradiance and overheating of the inverters. Based on the behavior of the measured solar irradiance, there are several rapid oscillations, and over the days, most of the measured curves are superior to the clear sky model, caused by a transient effect of the atmospheric boundary layer. Two photovoltaics systems–SFCR, were analyzed using the same model and inverter power but with a different inverter design factor. The SFCR were installed in southern Brazil 30 km apart. According to the inverter operating temperature monitoring data, it was also possible to prove the occurrence of the overtemperature to which the inverter with lower SFI is subjected, reaching operating temperatures on the order of 80 °C. SFCR A had higher solar radiation of 4.2% over the year compared to SFCR B; however, SFCR B had a higher final yield of 11.86%. In this way, PV systems with undersized inverters will be losing electricity generation, in addition to reducing their useful life due to component stress, resulting in inverter changes over the life of the PV system.

Studies have shown that night-time ventilation can greatly reduce indoor overheating during hot spells. Yet the relevant literature is largely silent on which specific time resolved window ventilation behavior can be applied for investigations with building performance simulations. The aim of this article is to close this gap in knowledge. Specifically, a survey was carried out in two German cities Dresden and Erfurt regarding window ventilation behavior on hot (outside temperature > 30 °C) and average summer days to determine how, when and for how long ventilation is actually implemented in residential buildings. The results show that approximately 80 % of respondents ventilate their living rooms and bedrooms mainly at night and/or in the early morning on both hot and average summer days – although the individual window ventilation behavior may vary significantly. The details provided by the respondents were processed to create characteristic window ventilation profiles in order to reflect the individual user behavior more realistically in future studies, especially for overheating evaluations by building performance simulation

Insulation systems of electrical apparatus (fluid and solid) include transformer oil, insulating paper, glass, ceramic, mica and rubber. Normally, they are designed well to be stable at high temperatures and provide excellent electrical insulating properties in different operating loads. There is an increasing demand to modify the effectiveness and capabilities of these insulation systems to overcome various issues (e.g., overheating, overloading and short circuits). Moreover, they should match the new high voltage insulation requirements, safety, ultra-high voltage, and being environmentally friendly are some of them. Nanoparticles (NPs) are promising compensator materials that can be used to develop insulation systems with good thermophysical and dielectric properties. The results of many studies show marvelous enhancements in electrical and thermal properties. In this paper, the authors present a review that focuses on different NPs that are used in several aspects of insulation systems to improve the dielectric as well as the heat transfer properties of high voltage insulation applications. The review covers NPs types, the preparation methods, analysis approaches, different properties, performances and results, challenges, and the limitation of the use of NPs.

Aiming to an integrated starter generator (ISG) application with a compact dimension requirement, this article proposes an axial flux machine with the internal rotor (AFIR). Compared with the traditional AFIR, the proposed machine shows a 21% increase in torque density due to its excellent thermal performance, which is implemented by suppressing the rotor losses and enhancing the cooling capability of the stator. The rotor design adopts the segmented permanent magnets and the separated rotor covers to prevent overheating. The loss analysis is carried out through the three-dimensional finite-element method (FEM). The results indicate that the optimized rotor loss is 24% less than the original design. After that, an innovative cooling system with the cooling rings and modified assembly process are proposed. Based on the lumped parameter thermal network and FEM, the improvement of thermal performance is investigated in detail. Compared with the conventional cooling system, the proposed one reduces the temperature of the machine by more than 20 ○C. Finally, this article provides experimental verification based on a 100-kW prototype. The experimental results are in agreement with the analysis and indicate that the proposed AFIR is a promising candidate for the ISG.

The building sector is – directly or indirectly – the first pillar for application of technologies aimed at reducing energy wastes. To achieve sustainable growth goals, worldwide, the building stock needs to be re-developed from the energy viewpoint. This study focuses the attention on the building envelope, since it is the primary subsystem through which energy losses occur between inside and outside environments, by reviewing and discussing the most recent and cutting-edge researches in matter of double-skin and responsive facades for the building retrofit. Each study is investigated by characterizing the technology, the location (i.e., the climatic conditions) and season of analysis, the building intended use and the main findings. The objective is identifying potentialities and recurrent benefits related to the discussed retrofit solutions – such as reduction of energy consumption and CO2-equivalent emissions, exploitation of renewables, conceptual transformation of the building envelope – but also barriers and criticalities – such as overheating risk, lower efficiency of transparent photovoltaics compared to traditional ones, high cost of responsive elements – which have to be addressed and solved in the future. In this vein, a comprehensive snapshot of the evolution of building envelope retrofit solutions is provided with original insights into current and future trends with a view to low- (or zero-) energy buildings. Despite the critical aspects and barriers to overcome, the potential advantages make most of the addressed technologies an important tool to achieve the sustainable renovation of the existing building stock, and therefore their potentialities must be deeply investigated and understood.

A major technical barrier of solar water heating systems for space heating and domestic water usage is the mismatch between the seasonal availability of solar energy and demand loads. The resulting low solar fraction in winter and high risk of overheating in summer reduces the competitiveness of this technology. Aiming to solve this problem, a novel collector module which combines asymmetric compound parabolic reflector with horizontally aligned evacuated tubular absorber is proposed in this paper. The special configuration enables the reflector to realize the seasonal dual function which performs as a concentrator in winter and a shading device in summer. This collector design can achieve high thermal performance during winter when demand is high and lower the efficiency in summer when demand is low. Based on the design principle, a prototype device was fabricated. Its photo-thermal behavior was investigated by the numerical approach as well as the experimental approach under real outdoor conditions on summer and winter days. Both theoretical and experimental results revealed that the prototype device has a high average optical efficiency on clear December days of 0.70, whereas it maintained low average optical efficiency of 0.39 on clear August days. In addition, the daily thermal efficiency remained above 0.5 for a large temperature difference between the fluid and ambient air at 77 K during the testing days around the winter solstice. These results confirmed that this solar unit achieves satisfactory performance in winter and also reduces the overheating risk in summer.

How should monetary policy respond to capital inflows that appreciate the currency, widen the current account deficit and cause domestic overheating? Using the workhorse open-macro monetary model, we derive a quadratic approximation of the utility-based global loss function in incomplete market economies, solve for the optimal targeting rules under cooperation and characterize the constrained-optimal allocation. The answer is sharp: the optimal monetary stance is contractionary if the exchange rate pass-through (ERPT) on import prices is incomplete, expansionary if ERPT is complete – implying that misalignment and exchange rate volatility are higher in economies where incomplete pass through contains the effects of exchange rates on price competitiveness.

As a thermal barrier coating (TBC) is exposed to elevated temperatures, oxidation proceeds at the interface between the top coat of the TBC and the bond coat/substrate. This aluminium-rich layer, in the case of the TBC studied in this work, produces an alumina thermally grown oxide (TGO) at the interface. This layer continues to grow as the exposure time increases and is prone to cracking. Failure of the TGO creates a debond which will affect the heat transfer through the system and lead to localised overheating. Samples of an IN6203DS substrate with a CoNiCrAlY bond coat and YSZ top coat have been thermally aged and a selection of these used to determine the morphology of cracking within the TGO. This quantitative information has subsequently been used to determine the effect on the heat transfer performance of the TBC system using a process of inverse modelling.

Due to the high power density characteristics of permanent magnet (PM) traction motors and the strict loading conditions of electric vehicle (EV) engine compartments, the excessive losses inside the motors can elevate rapidly the temperature rises, deteriorate the magnetic property of PMs, limit the output torques, and even cause the overheating damages of the machines. In order to guarantee the operational reliability, it’s of vital importance to research and develop the effective, reliable and economical cooling systems for improving the working performances of the PM traction motors. In this paper, the three-dimensional (3D) fluidic-thermal coupled model of a high power density interior PM traction motor is established based on the basic theory of computational fluid dynamics (CFD) and numerical heat transfer. The fluid flow and thermal distributions are analyzed based on finite volume method (FVM), and verified by experimental results. According to the heating characteristics of the motor, the external water frame structure of the motor shell is modified to improve the cooling efficiency. Taguchi method is used to optimize the cooling structural parameters, so as to reduce the steady-state temperature rise of the motor. The research work in this paper has certain reference significance for the design and development of high power density PM traction motors used in EV applications.

The paper investigates the basics for increasing the productivity of gas-phase catalytic oxidation processes effected in multi-tubular reactors due to their operation at more concentrated feedstock. Obviously, an increase in initial concentration of the oxidizable reagent seems very attractive, but it is associated with the need to modify the process parameters and/or technological chart in order to achieve the required performance figures. This often entails excessive formation of by-products and therefore overheating of the catalyst bed due to increased heat generation. The cumulative effect of many factors can prevent attaining an acceptably high conversion of feedstock and the yield of target products within a reasonable size of a multi-tubular reactor. The problems we studied are quite typical for highly exothermic catalytic oxidation processes, but are not widely discussed in the literature. On the example of nicotinic acid (NA) synthesis in multi-tubular reactor, we investigated the advantages of the process with elevated feed load (β-picoline), in comparison with the conventional conditions. On the basis of comprehensive process simulation supported by the experimental evidence, for the first time we have shown how the process should be operated to achieve a significant progress in the reactor performance and the target product yield. Our theoretical study showed that the rise in the initial β-picoline concentration from ∼0.8 to ∼3% accompanied by a relevant adjusting of the process parameters leads to a dramatic 1.5–2-fold gain in the specific productivity of catalyst; this could greatly improve the reactor capacity. Optionally, a given production capacity of multi-tubular reactor may be ensured by ∼2 times less number of tubes. Thus, the synthesis of NA at elevated initial feed of β-picoline shall be significantly enhanced in comparison with the conventional process.

The object of research is thermal processes in Langevin-type piezoceramic electroacoustic transducers (PET), taking into account the housing. The piezoceramic electroacoustic transducers heat up during operation. Overheating of the converter leads to negative consequences, accompanied by a change in the parameters, characteristics of the device, as well as the failure of the converter. Or limitation on the duration and mode of operation, output power, current, amplitude and speed of oscillation of the converter. The paper investigates the effect of the housing on the temperature field of a Langevin-type PET by the finite element method, using modeling in SolidWorks. The results of temperature reduction of such cooling methods are shown: –filling the housing cavity with electrical insulating liquid, gas, a mixture of thermal paste; –use of holes in the housing; –changing the shape of the rear cover to have radiator side fins, vertical radiator fins, cylindrical radiator fins; –heat-resistant layer; –use of active air cooling at three different speeds. The most efficient 53% and a uniform temperature field were found when filling with a mixture of thermal paste, but this solution is accompanied by additional experiments and a preparatory stage with the mixture. The cooling efficiency of 47% was provided by active cooling – blowing with air, and this method requires additional equipment. Filling with insulating liquid gave a cooling efficiency of 27% – an optimal result that does not require expensive investments. Slow blowing of the housing or adding only holes resulted in a decrease in the maximum heating temperature from 10 to 20%, therefore, if the PET design allows the presence of holes, then it is necessary to rationally place them. Changing the shape of the back plate, heat-absorbing element, filling the housing with gas gave an efficiency decrease in the maximum temperature by 6–8% compared to a closed housing with air. The research results make it possible to choose the optimal option for reducing the heating temperature of the Langevin-type PET to increase its efficiency and long-term trouble-free operation.

To study the transverse temperature uniformity with transverse flux induction heating (TFIH) during endless strip production (ESP) rolling, a coupled electromagnetic-thermal finite element model of transverse flux induction heating is established. The initial temperature distribution at the TFIH inlet is taken into consideration, which is the basis of subsequent numerical studies. Magnetic screens are designed to weaken the influence of edge overheating, and the influence of magnetic shielding amounts on temperature uniformity is discussed. Moreover, an evaluation criterion is provided to determine the temperature uniformity. Furthermore, the effect of different shielding amounts on the edge temperature is studied. An ideal temperature distribution at the TFIH outlet is obtained based on a model combining various shielding amounts, and the temperature standard deviation of this method is 2.01% lower than the traditional arrangement of magnetic shielding amounts. Actual data are collected to verify the results of the proposed model. The temperature deviation between the middle and edge is approximately 12°C, and the temperature uniformity is enhanced with the optimized combination of magnetic shielding amounts.

A compact 3D thermal model is developed for the quick and accurate thermal characterization of self-heating in Back-End-of-Line (BEoL) interconnect network for reliability assessment. The model offers a more accurate thermal tool compared to the currently used conservative 2D reduced models. Both 2D and 3D reduced models are developed and verified against numerical simulations of different configurations and further validated against thermoreflectance measurements of specially fabricated samples devices. The compact model ultimately provides quick thermal characterizations for vast ICT networks at a fraction of the analysis time and computational cost required for full numeric simulations, with improved accuracy that could reach 20 fold that of currently applied conservative reduced models. When integrated with electrical layout designs, the model would serve as a thermal check on VLSI and ULSI networks to identify thermally critical regions where overheating could lead to degradation and reliability issues.

The technology of direct extraction with nephras followed by the further miscella purification from the solvent and acid hydration (citric acid) is used to produce soybean oil. The miscella is cleared of solvent by passing through a range of heat exchangers and distillers. The final distillation unit is a 2-stage distillation apparatus operating at approximately absolute 400 mbar . A significant drawback of these installations is the irrational use of steam and its heat, the possibility of the finished product overheating and its quality deterioration, the process low speed, complex design and maintenance. To intensify the process of solvent evaporation from the miscella film in the structure of the troughs in the film chamber, it is advisable to install cylindrical or slotted holes through which free falling jets of miscella are formed sequentially from the overlying loop of the trough to the plane of the underlying one. In this case, the miscella film moving along the chute has a certain hydrodynamic instability at the points of flow and the fall of the jet on the plane of the chute. Directly in the jet, the liquid, as a rule, is turbulized, and there is no laminar film. This technique significantly intensifies the distillation process. An aeration system for supplying live steam, represented by a tubular bubbler, should be installed for intensification as well. The use of tubular aerators makes it possible to achieve an increase in the ratio of the aerated area to the total area of ??the section with the use of a smaller number of aeration elements and a reduction in the length of the pipelines (by 4 times on average ). As a result, the time and cost of installation are reduced significantly.

We devise an implicitly new design for boosting the light uniformity in the concentrated photovoltaics (CPV) system, whereby addressing the overheating issue of the PV cell and enhancing the electrical cell efficiency. Rather than using a well-known system of the Cassegrain concentrator design, consisting of double mirrors + a homogeniser, in this study, we mimic a structure of crustacean’s eyes for a design of homogeniser, consisting of an array of a mirror channel. Such proposed design allows making use of only a primary parabolic mirror + a homogeniser to concentrate and redistribute the sunlight, representing a large departure from virtually all of the previous studies. Specifically, such homogeniser can furcate the light beam into the small channels/trenches, redirect the light ray at the reflective plate and probably mix them to evolve a uniform version of light distribution. In general, the homogeniser can affect the uniformity and optical efficiency, which are good probes to assess the light performance, in a number of ways. We found that light performance depends sizably on the structural parameters such as the size and the number of channels of the homogeniser. The best structure displays a calculated uniformity of ~85% of the flux distribution on solar cell and a calculated optical efficiency of ~90% of the entire CPV system. We also assess the light performance against some scenarios of error in installation and operation processes such as tolerance and misalignment and compare well with the current design. The compelling of this proposed design is highly efficient light performance, compactness and inexpensive, which likely address virtually existing bottlenecks in the CPV system.

Required by the supercritical carbon dioxide (sCO2) coal-fired power cycle, sCO2 entering a boiler has a high temperature and can cause overheating of tubes. To eliminate the pressure drop penalty effect, the sCO2 boiler consists of several modules, each having different heat flux received from the furnace side (q) and different CO2 temperature in the cooling wall tube (Tf). We aim to search for the best matching strategy coupling furnace side and tube side to obtain the lowest temperature of tubes. By theoretically analyzing the wall temperature influenced by q, Tf and a comprehensive thermal resistance C, two matching methods are introduced: the heat flux-temperature matching (HTM) which matches higher q with lower Tf, and the heat flux-heat flux matching (HHM) that matches higher q with higher allowable-heat-flux at the temperature limit of tubes. HTM is a conventional method but HHM is newly proposed here. We show that, if C is identical for different modules, the two methods coincide; otherwise, HHM is recommended. For a sCO2 boiler driving 1000 MWe power plant, smaller cooling wall temperatures are obtained by HHM than HTM. Based on HHM, the mid-partition wall, heat transfer enhancement, and downward flow are comprehensively used, decreasing the wall temperature significantly.

The demand for miniaturised electronic devices has led to various challenges in microelectronic industries. One of the challenge is the removal of fans in some applications, which has led to increased heat retention, thereby causing overheating. In the assembly of electronic devices, thermal interface materials (TIMs) can be used for bonding the surface between the flip chip and a heat sink base or heat spreader. Lead-free solder (Sn-Ag-Cu) alloys are becoming more popular as TIMs in electronic assembly. Therefore, these lead-free solders could fail during operation at elevated temperatures over a period of time. The reliability of lead-free TIMs is vital in sustaining the life span of an electronic device. Three Sn-Ag-Cu (SAC) solders were considered for this investigation, namely, SAC305, SAC105, and SAC396. An ANSYS design modeller was used in the design and analysis of the microelectronic application investigated. Temperature loads ranging between 100°C and 200°C were applied over a period of time during the simulation of the electronic package. The findings from the research suggested that the SAC305 solder TIMs will outperform SAC105 and SAC396 during operation. This is because SAC305 can accommodate more stress, while the strain rate is low compared to SAC105 and SAC396. In addition, the fatigue life of SAC305 was higher than that of SAC105 and SAC396 in the different temperature ranges investigated. Therefore, SAC305 is recommended as a better thermal interface material compared to SAC105 and SAC396.

Battery performance is affected by the problem of overheating which can cause mechanical damage to the battery and electronic components of the BMS (Battery Management System). With the need for an increase in battery charging time with fast capacity, the internal heat generated by the battery also increases so that the battery pack needs to be equipped with a cooling system. Currently, the cooling system in the battery pack uses a lot of cooling plate, cooling pipe, PCM (Phase Change Material) and cooling fluid. Combining cooling system design based on advantages and disadvantages to produce the best performance was tried using the cooling plate and PCM. The method used is to change the initial design of the battery pack without cooling to a cooling system by making a design and verifying the design. The process of thermal analysis is carried out in the process of charging the battery and removing the battery. The result of the research is the distribution of heat transfer that occurs during the battery charging process and the battery discharge is uniform and the temperature value obtained is the 43,2 ° C battery discharge process in the main cooling plate component and the maximum temperature in the charging process is 57,6 ° C . at BMS. Cooling using a cooling plate and PCM for a closed system is maximized. Keywords : baterai Litium-Ion, Heat Sink, PCM

THE PURPOSE. System efficiency and competitiveness assess of a new scheme for combining a nuclear power plant with a hydrogen complex based on additional heating of feed water and superheating of live steam in front of the high-pressure cylinder of a steam turbine. METHODS. Basic laws of thermodynamics were applied when developing and substantiating a new scheme for combining a nuclear power plants (NPP) with a hydrogen facility; theoretical regularities were applied of heat engineering; basic regularity were applied of fatigue wear of power equipment and assessment of its working resourse; basic regularities were applied for the assessment of operating costs and net present value (NPV). RESULTS. A new scheme is presented of the combination of a nuclear power plant with a hydrogen facility and a description of its operating principle on the example of a two-circuit nuclear power plant with a VVER-1000 reactor and a C-1000-60 / 1500 turbine. The data are presented on an increase in the productivity of steam generators at nuclear power plants with additional heating of feed water in the range of 235-250 ° C from its nominal value of 230 ° C. The temperature was estimated of live steam superheat depending on the temperature of the additional heating of the feed water. The results are presented of the calculation of the generated peak power by the power unit and the efficiency of conversion of the night off-peak power of the NPP into peak power, as well as the efficiency of the power unit of the NPP depending on the temperature of additional heating of the feed water. Main regularities are given for taking into account the fatigue wear of the main equipment of the hydrogen facility, including the rotor of the NPP turbine in the conditions of the stress-cyclic operation. The results are presented of assessing the cost of peak electricity NPP in combination with a hydrogen facility in comparison with a pumped storage power plant (PSPP) both for the current period and for the future until 2035. CONCLUSION. Hydrogen facility efficiency and competitiveness depends significantly on the intensity of the use of the main equipment in the conditions of the intense-cyclic operation. The hydrogen facility will competitiveness noticeably increase in comparison with the PSPP in the future. Efficiency of the NPP power unit and NPV is highest when the feed water is heated to 235 ° C and superheating of live steam in front of the high-pressure cylinder of the C-1000-60/1500 turbine up to 470°C.The hydrogen facility competes with the PSPP with her specific capital investment at the level of 660 USD / kW, provided that the boosting capabilities of the turbine are used with live steam overheating at 300 ° C and additional heating of feed water to 235°C on the current period. The PSPP does not compete with the hydrogen facility both for the current period and in the future with her specific capital investment of $ 1,500 / kW and above.

Variable Refrigerant Flow (VRF), also known as Variable Refrigerant Volume (VRV) refers to the ability of an air-conditioning (AC) system to control the amount of refrigerant flowing to multiple evaporators (indoor unit). This study evaluates the VRF system to its core, and how the system is more beneficial in terms of built environment than the traditional air-conditioning system. This type of type of system consists of a number of air handling units (possibly up to 48) connected to a modular external condensing unit. The refrigerant flow in the VRF system is varied using either an inverter-controlled variable speed compressor or multiple compressors of varying capacity in response to changes in the cooling or heating requirement within the air-conditioned space. With the help of these advanced compressor like the twin rotary compressor the metering device can be closed to controls the flow of refrigerant between the indoor and outdoor unit which helps in avoiding the overheating or overcooling of the space. VRF system also helps in covering the duct losses which is impossible to cover in traditional system as VRF system is ductless or minimum duct are used in the process.

Radio frequency (RF) microelectromechanical systems (MEMS) based on Al1-xScxN are replacing AlN-based devices because of their higher achievable bandwidths, suitable for the fifth-generation (5G) mobile network. However, overheating of Al1-xScxN film bulk acoustic resonators (FBARs) used in RF MEMS filters limits power handling and thus the phone's ability to operate in an increasingly congested RF environment while maintaining its maximum data transmission rate. In this work, the ramifications of tailoring of the piezoelectric response and microstructure of Al1-xScxN films on the thermal transport have been studied. The thermal conductivity of Al1-xScxN films (3-8 W m-1 K-1) grown by reactive sputter deposition was found to be orders of magnitude lower than that for c-axis-textured AlN films due to alloying effects. The film thickness dependence of the thermal conductivity suggests that higher frequency FBAR structures may suffer from limited power handling due to exacerbated overheating concerns. The reduction of the abnormally oriented grain (AOG) density was found to have a modest effect on the measured thermal conductivity. However, the use of low AOG density films resulted in lower insertion loss and thus less power dissipated within the resonator, which will lead to an overall enhancement of the device thermal performance.

Reduction gases are widely used in the metallurgical, chemical and other industries. In this paper, the possibility of higher-quality reduction gas production using a two-stage technology is considered. It is proposed to use air conversion of natural gas with cooling and drying of the obtained products at the first stage. At the second stage, gas mixture is heated, treated in the catalyst bed, quenched and dried. It is established that the temperature of heat treatment of the gas mixture at the second stage should be at least 850–950 °C. This allows to increase the ratio (CO − H2)/CO2 in the resulting reduction gas. The minimum gas treatment temperature at the second stage is calculated depending on the pressure in the system. By overheating the gas before it enters the catalyst bed in the second stage, it is possible to compensate for the heat required for chemical reactions in temperatures above 850 °C, the total thermal effect of chemical reactions is determined. The total heat effect of chemical reactions depending on the temperature of gas heat treatment at different pressure is defined.

Approximately 2.5 billion won can be saved every year by replacing existing induction motors, which are traction motors for urban railway vehicles, with permanent magnet motors. This paper presents a study on the structural design of a completely enclosed motor to commercialize an interior permanent-magnet synchronous motor (IPMSM) for the traction of urban railway vehicles. The proposed solution provides protection from an inflow of dust and magnetic powder into the rotor that can deteriorate the motor performance and cause burnout. In addition, unless it is a water-cooled or oil-cooled structure, cooling of an electric motor used in medium and large-sized equipment is not easily accomplished. However, completely enclosed motors are vulnerable to overheating; therefore, research into housing design is required to provide cooling. Additionally, the permissible current density through the stator winding must be considered in the design to prevent the occurrence of thermal demagnetization of permanent magnets. Furthermore, IPMSMs require a separate driver for operation and speed controls for a wide range of operating conditions such as rail traction. Thus, a study has been conducted on IPMSMs and other related driver and control technologies, and their suitability has been validated through performance tests.

The temperature at the end of the aluminum billet with a large radius is higher than that in the middle at the end of heating even the aluminum billet is heated by rotating with low velocity, which makes the aluminum billet have a risk of local melting and is bad for the quality of the product. In order to improve the axial temperature uniformity and avoid local melting, a new method based on a 1MW HTS DC induction heater has been proposed. In the method, the regulation of the magnetic flux density distribution in the heating area can be achieved by adding different barrel-shaped ferromagnetic blocks around the aluminum billet, and the resultant adjustment of the temperature distribution of the aluminum billet has also been investigated. The results show that the magnetic field is strengthened in the aluminum billet area covered by the ferromagnetic block and weakened in the remaining aluminum billet area, which is good for solving the overheating problem at the aluminum billet ends during the heating process. The magnetic flux density distribution in the heating area can be adjusted by changing the cross-sectional shape and the size of the ferromagnetic block. And the desired axial temperature uniformity of the aluminum billet can be obtained by using an appropriate ferromagnetic block. What is more, the heating time taken to heat the aluminum billet to a given temperature is shorter with a proper ferromagnetic block than without it, and the risk of local overheating can also be avoided.

This study introduces a developed, movable, and pilot-scale microwave drying equipment with an automatic control system for the treatment of solid organic waste. Based on a previous study, the structure of the reactor and the arrangement of the magnetron were improved to make the material absorb microwave energy more uniformly and efficiently. The equipment added the auxiliary hot plate and air extraction system, which effectively solved the influence of the occurrence condensate water in the microwave irradiation room on the drying efficiency and energy consumption. The microwave drying behavior of the existing constant-power mode was compared with the improved constant-temperature mode. The experimental results showed that the latter mode could effectively solve the partial overheating of the material caused by uneven heating. The constant-temperature mode was more advantageous in product quality, safety, and selectivity. The advantages and disadvantages of the equipment were analyzed by comparing it with the other existing pilot-scale microwave drying equipment. The proposed system showed good performance. Thus, the newly developed mobile microwave drying system has great potential for practical application.

Dissolved gas analysis is the most common and well-established method used in identifying internal faults of power transformers. However, an onsite analysis using this method accuracy still need to be improved while the laboratories analysis process takes longer time. New alternative onsite and online method are most urgently need to be studied. Power transformer faults identification based on extended application of polarization and depolarization current (PDC) measurement data on oil sample from in-service power transformer was investigated in this research. The changes in the molecular properties of the insulating oil due to different fault conditions found had influenced the initial time response of the PDC measurement (from 0 to 100 s). In this research, the unique characteristic pattern of each condition was determined by a single unique numerical dimensionless quantity known as depolarization ratio index (DRI). DRI is used to express the changes of depolarization current shape with different fault conditions. The ratio of depolarization current between 5/100 and 10/100 s was found to have a better correlation at least more than 90% on the incipient fault in power transformer. Indeed, the DRI at 5/100 also was observed has higher accuracy especially on units with normal, overheating and arcing condition. In addition, a graphical representation of DRI value at 5/100 and 10/100 s was proposed for fault recognition in power transformer. Both DRI and graphical representation are well validated, and the proposed interpretation techniques have accuracy of more than 90% and able to identify and classify the normal, overheating and arcing condition of the in-service power transformer.

The article discusses the need for the use of automated air conditioning systems in mobile complexes. It is due to the need placing the mobile complex in the place that allows work to be carried out, and such places can be located in uncomfortable for human’s conditions. The air conditioning system of the complex is investigated as an object of regulation, a generalized block diagram with the main input and output parameters, as well as components and processes occurring during air cooling and heating, is presented. The article provides an example of the implementation of automation of a single-zone air conditioner in a mobile complex by the method of performance adjustment. This method is realized by using a frequency inverter and is able to significantly reduce inrush currents, ensure efficient energy consumption and provide the highest level of component protection against unexpected accidents and breakdowns. The article describes in detail the main advantages of inverter performance control, and also shows the main elements of compressor protection using tuned automation. Considered in detail timing diagrams of fans speed in the process of inverter control of the air conditioning system. These diagrams show that in the inverter capacity control method, there can be quite a large number of operating speeds. Separately, a cyclogram of compressor overheating protection is given, which proves its high degree of protection. In the end of the article, gives conclusions and general results of the work that shown that inverter control is the only correct choice for mobile complexes air conditioning systems automatization.

The impact of low-carbon technologies, like renewable energies and electric vehicle (EV) charging stations, will be an additional strain in terms of voltage violation and current congestion on the low-voltage network, resulting in a reduced quality of supply and overheating assets. To avoid or defer the replacement of these traditional assets, the network of the future needs an intelligent solution such as smart transformers (STs) [1]. The ST is a solid-state transformer with smart control functionalities as proposed in [2].

Urban overheating (UO) may interact with synoptic-scale weather conditions. The association between meteorological parameters and UO has already been a subject of considerable research, however, the impact of synoptic-scale weather conditions on UO magnitude, particularly in a coastal city that is also near the desert landmass (Sydney) has never been investigated before. The present research examines the influence of synoptic-scale weather conditions on UO magnitude in Sydney by utilizing the newly developed gridded weather typing classification (GWTC). The diurnal, and seasonal variations in suburban-urban temperature contrast (ΔT) in association with synoptic-scale weather conditions, and ΔT response to synoptic air-masses during extreme heat events are investigated in three zones of Sydney. Generally, an exacerbation in UO magnitude was reported at daytime over the years, whereas the nocturnal UO magnitude was alleviated over time. The humid warm (HW), and warm (W) air-masses were found primarily responsible for exacerbated daytime UO during extreme heat events and in all other seasons, raising the mean daily maximum ΔT to 8–10.5 °C in Western Sydney, and 5–6.5 °C in inner Sydney. The dry warm (DW), and W conditions were mainly responsible for urban cooling (UC) at nighttime, bringing down the mean daily minimum ΔT to − 7.5 to − 10 °C in Western Sydney, and − 6 to − 7.5 °C in inner Sydney. The appropriate mitigation technologies can be planned based on this study to alleviate the higher daytime temperatures in the Sydney suburbs.

Building-integrated photovoltaics/thermal (BIPV/T) systems are capable of generating electricity and heat simultaneously. Several strategies have been proposed to integrate PV into a building structure to increase the efficiency of the whole system, provide indoor heating, and produce hot water. The purpose of this paper is to comprehensively review some new and efficient technologies being employed to benefit from BIPV/T systems for indoor heating. The integration of PV into the structure of buildings and the technology of thermal management have to be straightforward. Therefore, in the present work, temperature regulation of PV cells is comprehensively reviewed considering potential methods i.e. air-assisted cooling and the use of phase change material (PCM). In addition, this paper evaluates previous works on thermal management of BIPV/T—air-based and PCM based—for space heating. Special attention is given to the effects of various configurations on buildings’ thermal load, and the possible methods for system operation analysis. Furthermore, related issues such as PV and building overheating are discussed and recommendations are provided for future research studies.