Design Of Heating System Research Articles

Building Energy Simulations Based on Weather Forecast Meteorological Model: The Case of an Institutional Building in Greece

The vision of decarbonization creates the need to design and construct even more energy-efficient buildings. This current target is even more compelling and challenging. The main issue when designing energy-efficient buildings is to identify present and future building energy requirements. A trending method for solving this problem is dynamic building energy simulation. One of the main inputs during energy simulation is weather data. However, the real problem lies in the fact that standard weather data are good at defining the present situation, and they help in designing buildings that behave efficiently under current climate conditions. To achieve the goal of constructing climate proof buildings, the Weather Research and Forecast meteorological model (WRF) was used to predict future climate scenarios. At first, data from previous years (2006–2010) were used to represent the current climate. The model was used to generate future climate data. Thus, results were produced for 5 year periods 2046–2050 and 2096–2100. These data were used for the energy simulation of an office building in Thessaloniki, Greece. The simulation results showed a reduction in heating loads by approximately 20% in the long term and a simultaneous impressive increase in cooling loads by 60%, highlighting the inadequacy of the existing building shell, as well as the heating, ventilation, and air-conditioning (HVAC) system design.

Specifying boundary conditions for the operation of pipe heating systems with impact on the building energy balance

Unaddressed boundary conditions in the design of heating systems affect the energy balance of buildings, especially in buildings with very low energy consumption. Buildings with very low energy consumption are very sensitive to any heat flow and neglecting realistic heating water parameters affects their energy balance. Two simulation models of the end part of the heating system have been developed. The first simulation model shows the effect of the inaccuracy of the designed heating element on the calculated room temperature. The second model shows the hydraulic behaviour of the connection pipes of the designed heating element.

Distribution characteristics of particles in room with capillary radiant floor heating system

Based on discrete phase model (DPM) and Euler-Lagrange method, a heat transfer model is established for capillary radiant floor coupled with indoor particle diffusion in this paper. The distribution is analyzed for the temperature in surface of floor and particles in indoor room. The concentration distribution characteristics of indoor particle in different sizes are further analyzed under the condition of different floor finishing layers. The results show that many particles are deposited around human body and the wall, and the diffusion height of particles in different sizes increases with the increase of floor surface temperature. Meanwhile, the 2.5 μm particles are more greatly affected by temperature difference and diffuses broader compared with 10 μm particles. The concentration of 10 μm particles decreases more obviously in height direction than that of 2.5 μm particles. In addition, the concentration of particles is the highest at the height of 0.6 m children breathing height. The results are significant for improving the design of capillary radiant floor heating system.

Demand response with heat pumps: Practical implementation of three different control options.

Three case studies of different heat pump demand response control strategies in real homes are presented. All three households reduced their electricity consumption during a peak period but delivered unintended consequences where the heat pump's logic did not correspond to the demand response requirements. This study highlights that the implementation of heat pump demand response to support electricity system operation requires a clear definition of electricity system need as well as practical demand response mechanisms to be integrated into heating system design.

Winter indoor thermal environment and heating demand of low-quality centrally heated houses in cold climates

In northern China, district heating systems without terminal control typically serve thousands of end-users, thus inevitably some users suffer from insufficient warmth and others are overheated indoors due to hydraulic imbalances. This paper aimed to understand the indoor thermal conditions and the actual heating demand in low-quality centrally heated dwellings. The driving force of heating demand was analyzed based on a smartphone survey of 233 households in cold climates, and field measurements of winter indoor thermal environment and AC supplemental heating behavior were conducted in a sample of 13 cool dwellings. Logistic regression and heteroskedasticity-robust Ordinary Least Squares were adopted to assess AC usage patterns and driving forces of heating demand, respectively. New knowledge has been gathered regarding average temperatures of 17.4 ℃ and 16.8 °C in cool housing living rooms and bedrooms, respectively, outside the human thermal comfort zone. Simultaneously, intermittent and partial AC usage patterns induced by time and air temperature were observed in these cool end-users for the comfort. The average daily running time of AC devices was 2.0 h for the living room and 1.8 h for the bedroom. There were statistically significant base linking occupants' heating demands to education level, household income, tenure type, presence of children, thermal experience and heating system. However, it was not a significant factor for household size. In addition, a rebound effect of building energy efficiency improvements on the interior temperature was also noticed. The results of this study shed light on better and target-oriented residential internal temperature or heating system design for both thermal comfort requirements and energy-savings.

Failure mode and reliability study for dynamic confinement and conditioning of the IFMIF-DONES radiological areas

The reference engineering design of the IFMIF-DONES nuclear Heating, Ventilation, and Air Conditioning system (HVAC) has been analyzed in terms of potential failure modes and consequences as well as life-cycle reliability and availability. The HVAC system performs the safety function of preventing lithium fire and uncontrolled releases of radioactive materials from the radiological areas. The results of the Reliability, Availability, Maintainability and Inspectability (RAMI) analysis are of high practical importance for future activities on the system optimization and safety demonstration. This paper proposes a unified approach to the Failure Mode and Effects Analysis (FMEA) that can be applied to the plant systems evaluation in terms of the failure frequency, severity, and detectability. The reliability and availability calculation has been performed for two sets of data, the U.S. NRC collection representing the industry standards of fission power plants, and the fusion-specific data gathered from several sources and integrated by Monte Carlo-based method. Inherent availability of above 99.4% has been reached for the HVAC system based on the fusion-specific data. The use of reliability data from the commercial fission plants increased the system availability to nearly 99.8%, thus indicating the potential for allocation of higher availability requirements to the HVAC functions.

Portfolio optimization in district heating: Merit order or mixed integer linear programming?

Long-term portfolio optimization is commonly used to find the most cost-effective design and operation of a district heating system, subject to technical, financial, and environmental restrictions. Optimizing a district heating system is not trivial and demands high accuracy and high computational speed. However, existing methods addressing this problem offer one or the other but not both at the same time. The state-of-the-art method for portfolio optimization is mixed integer linear programming (MILP), which is extensively used in industry and academia but can be computing and resource-intensive for large portfolio models. This limitation has motivated the development of various options to reduce the computation time while maintaining the accuracy to a large extent. An alternative method to MILP is the merit order (MO) method, which has been used especially for power generation applications due to its simplicity and faster computation but somewhat reduced accuracy. The aim of this paper is to investigate the potential advantages and disadvantages of MO models compared to MILP models in the context of optimizing the portfolio of assets supplying a district heating network. As a study case, we analyze a large portion of the district heating network in Berlin. Four MO model variants with different levels of complexity are proposed and compared to a reference MILP model. Results suggest that MO models variants including heat storage and describing CHP plants with significant detail have the potential to reduce calculation time by nearly three orders of magnitude compared to the reference MILP model, without significantly sacrificing accuracy. In fact, differences in heat generation and net present value (NPV) between the most accurate MO model and the reference MILP model account for ±4% and −6%, respectively. Moreover, results show that combining MO and MILP models is advantageous and offers high computational speed and at the same time high accuracy, especially when a large number of runs might be necessary. MO models could thus be used prior to MILP models to perform a pre-evaluation, an exploration of sensitivities, or for downsizing the initial optimization problem. Combining MO and MILP models could result in faster and more robust decision-making, which could otherwise not be attained with any of the two options individually.

New Heuristic Methods for Sustainable Energy Performance Analysis of HVAC Systems

Energy-efficient buildings have attracted vast attention as a key component of sustainable development. Thermal load analysis is a pivotal step for the proper design of heating, ventilation, and air conditioning (HVAC) systems for increasing thermal comfort in energy-efficient buildings. In this work, novel a methodology is proposed to predict the cooling load (LC) of residential buildings based on their geometrical characteristics. Multi-layer perceptron (MLP) neural network was coupled with metaheuristic algorithms to attain its optimum hyperparameter values. According to the results, the LC pattern can be promisingly captured and predicted by all developed hybrid models. Nevertheless, the comparison analysis revealed that the electrostatic discharge algorithm (ESDA) achieved the most powerful MLP model. Hence, utilizing the proposed methodology would give new insights into the thermal load analysis method and bridge the existing gap between the most recently developed computational intelligence techniques and energy performance analysis in the sustainable design of energy-efficient residential buildings.

Battery lifetime extension through optimal design and control of traction and heating systems in hybrid drivetrains

In this paper, we investigate the optimal design and control of an integrated energy and thermal management system (IETMS) of a battery-assisted trolley bus that is subject to minimum battery lifetime requirements. Therefore, we jointly optimize both the control trajectories of the traction and the heating systems and the design of the thermal energy buffer. We further analyze the resulting Pareto fronts which characterize the trade-off between the battery lifetime and the energy consumption. This holistic approach fills a gap in the literature published, namely the formulation of an optimization problem that combines component sizing with a battery-health-aware IETMS. While the model derived allows the formulation of a convex optimal control problem for a given vehicle design, the combined design and control problem is non-convex. Therefore, we perform grid searches within a reasonable subset of the design space and show that the problem is smooth, has only one stationary point, and that the solver converges to the optimal solution even for the simultaneous, non-convex problem formulation. We further present a case study showing that, if an IETMS is used, a realistic bus service life without battery replacement can be achieved with a reduction of energy consumption of up to 7% on some driving missions, compared to a heuristic heating strategy. If the design of the thermal system is co-optimized, battery lifetime can be extended further by up to 15% without affecting the amount of energy consumed. In summary, our study reveals a potential to make electric transportation more efficient in terms of both energy and costs based on a holistic consideration of battery-health-aware IETMS with optimized component dimensioning.

4 E analysis of DG set based micro combined heat and power (CHP) system and its employment for shelter heating in high altitude areas

Modern spectrum of combat and warfare calls for increased flexibility in operations of military bases through sustainable and adaptable designs churned out of various technological advancements. Micro CHP system is a niche technology which can be employed to reduce usage of fossil fuel for space heating in military bases and forward areas. Micro CHP systems improve energy efficiency, reduce CO2 emissions, and help to reduce cost of fuel burnt for space heating thereby reducing burden on huge logistic supply chain employed for maintenance of forward logistic bases and isolated posts. Considering their huge cumulative contribution in energy conservation and environment protection such systems have immense potential to be used not only in defence but across the nation in energy sector to help us achieve, goal of “ATMA-NIRBHAR BHAARAT” simultaneously ensuring achievement of national Sustainable Development Goals (SDGs).This paper highlights results of theoretical and experimental analysis carried out on DG set based Micro-CHP system at College of Military Engineering, Pune. It covers Energy, Exergy, Environment and Economic analysis of the system when employed for space heating of military shelters. It includes discussion on design of radiant heating system for military shelters using waste heat energy produced from DG set based Micro-CHP system in high altitude areas. 4E analysis reveals that efficiency of 62.5 kVA DG set is 31 % which after retro-modification into Micro-CHP system increases to 45 %. Exergy efficiency of DG set is 29.9 % which after retro-modification into micro-CHP system increases to 38.9 %. Employment of DG set post retro-modification into micro-CHP system for space heating results in 24 % reduction in carbon dioxide emissions and will lead to savings to the tune of INR 5.6 lacs annually on account of cost of fuel consumed in Bukharies/Kero-heaters used in high altitude areas for heating of military shelters.

Optimal Planning of Future District Heating Systems—A Review

This article provides the state-of-the-art on the optimal planning and design of future district heating (DH) systems. The purpose is to provide practical information of first-step actions for countries with a low DH market share for heating and cooling supply. Previous research showed that for those countries, establishing a heat atlas with accurate geographical data is an essential prerequisite to promote the development of DH systems. In this review, essential techniques for building a high-quality heat atlas are elaborated. This includes a review of methodologies for district thermal energy demand prediction and the status of the integration of sustainable resources in DH systems. In the meanwhile, technical barriers for the implementation of various sustainable heat sources are identified. Furthermore, technologies for the optimal planning of DH systems are discussed. This includes the review of current approaches for the optimal planning of DH systems, discussions on various novel configurations which have been actively investigated recently, and common upgrading measures for existing DH systems.

Feasibility Study of the CO2 Regenerator Parameters for Oxy-Fuel Combustion Power Cycle

The atmosphere carbon dioxide content grows subsequently due to anthropogenic factors. It may be considerably mitigated by the development of thermal power plants with near zero emissions. A promising way is the transition to the semi-closed oxy-fuel combustion power cycles with carbon dioxide and water vapor mixture as a working fluid. However, their wide implementation requires reduction of the metal consumption for the highly efficient regeneration system. This paper discloses the results of feasibility study for the regeneration system of the prospective oxy-fuel combustion power plant. The effect of operating parameters on the cycle energy efficiency, overall dimensions, and the cost of the regenerator was determined. Underheating increase in the regenerator by 1 °C leads to the net efficiency factor drop of the oxy-fuel combustion power cycle by 0.13% at average and increases fuel costs by 0.28%. Increase of pressure drop in the hot channel by 1% leads to efficiency drop by 0.14%. The optimum set of design and operating parameters of the feed heating system has been determined, which ensures the best technical and economic indicators of electrical power generation: the minimum cumulative costs are achieved when underheating in the regenerator is 20 °C and pressure drop in the hot channel is 4%, under the use of S-shaped fins channels.

A novel hybrid solar water heater system integrated with thermoelectric generators: Experimental and numerical analysis

This paper presents a full-scale experimental performance evaluation of a new design of a solar water heating system installed in the football pitches of the University of Tunis El Manar. Thermoelectric generators were incorporated into the heating system to utilize the wasted heat and use the temperature differences in water to generate electricity. To optimize system parameters, evaluate thermal efficiency, and predict long-term system performance for winter and summer operating weather conditions, a numerical model using the finite volume method and TRNSYS software was developed. For model validation, the simulation results are compared to the experimental data. The economic study was also presented, as well as the system's energy gain and lifetime energy savings. The thermal efficiency of the system was found to be 50 and 95 percent in January and July, respectively. Furthermore, the hybrid model reduced electrical consumption by 80%, and in areas with higher environmental temperatures, the reduction in the electrical bill could be up to 90%. The new hybrid solar system's energy savings over its lifetime are estimated to be $14400.

Design status of the ECRH system for CFETR

The China Fusion Engineering Test Reactor (CFETR) is the proposed next-generation fusion facility in China. During its two operational phases, a large fraction of externally driven current is foreseen to meet the scientific goals of the two operating scenarios for CFETR. As one of the key design activities of auxiliary heating mix for CFETR, the design of Electron Cyclotron Resonance Heating (ECRH) system is in progress considering the engineering and physical requirements. The conceptual design of the EC system, especially the launcher, will be presented in this paper. Based on the physical requirements and the technical availability, the frequency is chosen to be 170 GHz in order to draw on the technologies development with International Thermonuclear Experimental Reactor (ITER), and the Front Steering Antenna (FSA) is selected as an example to investigate the feasibility of the plant integration design. The beam tracing calculations have been performed to analyze the performance of power deposition and absorption from several launching points. The microwave and optical design of launcher has been carried out to evaluate the maximum power per port and minimize Breeding Blanket (BB) openings.

Hydraulic and thermal stability of independent systems of apartment heating

Introduction. Individual apartment heating has been used in the Russian Federation since 1998. More than two million wall-mounted gas boilers were installed in the apartments of apartment buildings, 99 percent of which are wall-mounted double-circuit convection boilers with atmospheric burners. Their hydraulic and thermal stability is a requirement of the current standards for the design of heating systems. The heat generator of independent heating systems is part of a single circulation circuit; it has its own hydraulic resistance. The circulation of coolant and transfer of thermal energy through the pipelines to heating appliances is performed by the circulation pump. Stability of an independent heating system, in contrast to the centralized one, depends on the regulatory parameters of energy supply (pressure, calorific value of gas, voltage of the electric network).
 Materials and methods. The authors studied the thermal capacity parameters of the gas burner and the circulation pump within the framework of current standards of variable supply of energy resources and their influence on the hydraulic and thermal stability of systems.
 Results. Quantitative results of the studied parameters were obtained. The authors identified the coefficient of heat power generation depending on gas pressure, range of pressure change and flow characteristics of circulation pumps, wall boiler hydraulic resistance, influence of thermostatic valves of heating appliances and the use of antifreezes.
 Conclusion. An independent heating system differs from a centralized one in that a heat generator and a circulation pump are its integral parts. The operating parameters of independent heating systems depend on standard parameters of energy resources supply. Hydraulic resistance does not determine thermal stability. When calculating the hydraulic resistance of the heating circuit, it is necessary to take into account the hydraulic resistance of the gas boiler. Thermal heads on heating appliances and antifreezes in the system of independent apartment heating contradict the concept of hydraulic stability of the heating circuit. Thermal stability of an apartment heating system should be checked taking into account the algorithms of the heat generator performance.

Design of the solar water heating system for local communities in Pakistan

Solar thermal energy has great importance in the improvement of active solar-powered systems. Performance evaluation of such systems is very complex due to the involvement of many operational factors. This study aims at evaluating the design of solar water heating systems (SWHS) for the residential sector. For a realistic estimation of design parameters, ASHRAE clear-sky-model is applied to assess solar energy potential, and then the SWHS performance is evaluated. The Scatter Search heuristic approach is applied to determine maximum solar thermal energy generation with the minimum possible total cost of the system, subject to several real-time constraints of the study area. The general-purpose optimization model is formulated, and here it is applied to the case study of a typical residential building of Islamabad, Pakistan. The results indicate the optimum system cost of 61000.14 PKR with a 6 m 2 collector area and 150 L TES tank. Maximum efficiency of 59.8% is possible to be achieved such that 6.68 kWh heat energy remains for the provision of hot water during non-sunshine hours. 150 L water would be available at the end of sun-shine hours at a temperature of 54.16 C o . The impact of mass flow rate, irradiation, and temperature on collector efficiency is performed through sensitivity analysis. Realistic estimations are important to attract the masses towards the venerated benefits of such innovated technologies and would be of great importance in selecting such systems for a particular residence having a specific load.

Optimizing the solar-air hybrid source heat pump heating system based on the particle swarm algorithm

In order to deal with the increasingly severe energy situation and climate change, reducing global carbon emissions and developing new energy have become a universal consensus among countries in the world. The design of clean energy heating systems such as solar collectors (SC) and air source heat pumps (ASHP) has also received widespread attention. However, optimizing multiple parameters that interact with each other in the hybrid heating systems such as solar-air hybrid source heat pumps (HSHP) is still challenging, and the optimization of the parameters remains to be studied. By using the TRNSYS simulation platform, modify the performance parameters to decrease the system’s annual cost with particle swarm optimization (PSO) and coordinate search method (CSM), respectively. The results show that two algorithms can significantly enhance the system performance, where it is the easier for PSO to find global optimum, and the average performance index COPsys of the system is about 15% higher than that of the CSM, and the system’s annual power consumption could be lowered by 27.75%; In addition, the matching principle of the key parameters of the hybrid heating system is proposed and the sensitivity ranking of the optimized parameters is derived. These results offer theoretical foundations for optimal design of the solar-air HSHP heating system.

A hierarchical layout approach for underfloor heating systems in single-family residential buildings

The layout of an underfloor heating system determines its heating performance. Conventionally, the design is completed by qualified experts using professional software, but this method is inefficient and heavily relies on the experts’ previous experience. This paper proposes a hierarchical approach for the automatic design of underfloor heating systems aimed at residential buildings, and the underfloor heating layout problem is decomposed into a routing problem and coverage path planning problem. First, the routing problem is formulated as a shortest path problem in an appropriate routing graph and solved to provide the routing of pipes for further coverage. Subsequently, a depth-first layout algorithm is developed to recursively simplify the coverage path planning problem to obtain the basic rectangle layout, achieving uniform coverage of the given layout zone. Simulation results on two houses show that, unlike one popular commercial platform, the proposed approach generated feasible solutions in all 13 test instances. The new method improved the minimum temperature, average temperature, average percentage of nodes greater than 30 °C, and total energy efficiency by 3.18 °C, 0.79 °C, 3.23%, and 4.19%, respectively, with a lower variance on average. These improvements lead to a higher coverage rate, more even thermal distribution, and stronger robustness under flexible parameter selection.

Experimental and numerical study on a new floor heating system using carbon fiber tape embedded in cement mortar

A new design for a floor electrical heating system manufactured with commercially available carbon fiber tape (CFT) as heating source embedded in cement mortar is proposed in this study. The characterization on thermal performance of the system was then performed to analyze the heating efficiency, temperature change with spatial and temporal variations, and energy consumption. The experimental results showed that the temperature of the CFT surface could increase at a rate of 1.83 °C/min through the heating system, and the heating flux is 16.31W/m2. Numerical analysis was also conducted on the heating panel and its associated heating system. The temperature gradient in the vertical direction is much greater than that in the horizontal direction. The heating power of the CFT is stable at a constant voltage, and the reflective film and insulation board effectively minimize the heat transfer towards the bottom of the device, thus enhancing the heating efficiency. The automatic temperature control device can also decrease energy consumption. The temperature increase and power-on time of the device are affected by the ambient temperature. The temperature change and distribution obtained by FE thermal analysis are in good agreement with the experimental results. Finally, the number and spacing of CFT are optimized to improve the performance of the heating system, and more uniform temperature distribution can be achieved using more CFTs with the same power consumption.

Modeling, Analysis, Design, and Simulation of a Bidirectional DC-DC Converter with Integrated Snow Removal Functionality for Solar PV Electric Vehicle Charger Applications

Different factors affect solar photovoltaic (PV) systems by decreasing input energy and reducing the conversion efficiency of the system. One of these factors is the effect of snow cover on PV panels, a subject lacking sufficient academic research. This paper reviews and compares current research for snow removal in solar PV modules. Additionally, this paper presents the design, analysis and modelling of a smart heating system for solar PV Electric Vehicle (EV) charging applications. The system is based on a bidirectional DC-DC converter that redirects the grid/EV-battery power into heating of the solar PV modules, thus removing snow cover, as well as providing the function of MPPT when required to charge the EV battery pack. A control scheme for each mode of operation was designed. Subsequently, a performance evaluation by simulating the system under various conditions is presented validating the usefulness of the proposed converter to be used in solar PV systems under extreme winter conditions.