Design Of Heating System Research Articles

Computational Fluid Dynamics Modeling of a Broiler House Microclimate in Summer and Winter.

Simple SummaryMicroclimate conditions in broiler housing are significant for maximizing poultry production and ensuring the welfare of the birds. In the present study, we modeled summer and winter microclimates in a mechanically ventilated broiler house. Validation of the simulated values was accomplished through comparison to field measurements. In visual simulations, the results were used to reconstruct microclimate conditions such as stagnant and stress zones of broiler houses. In conclusion, simulation techniques can be used as an alternative method for analyzing poultry house indoor environments.Appropriate microclimate conditions in broiler housing are critical for optimizing poultry production and ensuring the health and welfare of the birds. In this study, spatial variabilities of the microclimate in summer and winter seasons in a mechanically ventilated broiler house were modeled using the computational fluid dynamics (CFD) technique. Field measurements of temperature, relative humidity, and airspeeds were conducted in the house to compare the simulated results. The study identified two problems of high temperature in summer, which could result in bird heat stress and stagnant zones in winter, and simulated possible alternative solutions. In summer, if an evaporative cooling pad system was used, a decrease in temperature of approximately 3 °C could be achieved when the mean air temperature rose above 25 °C in the house. In winter, adding four 500-mm circulation fans of 20-m spacing inside the house could eliminate the accumulation of hot and humid air in the stagnant zones in the house. This study demonstrated that CFD is a valuable tool for adequate heating, ventilation, and air conditioning system design in poultry buildings.

Optimization of the solar space heating system with thermal energy storage using data-driven approach

The employment of solar space heating is a significant measure to achieve carbon neutrality. However, the design of the solar space heating system usually leads to the dilemma of a trade-off between the economic benefit and environmental protection, which cannot be solved by single-objective optimization. In this work, in order to design a solar space heating system of a bungalow equipped with radiant floor heating, multi-objective optimization of the solar collector area and the volume of the water thermal energy storage (TES) tank is performed by coupling TRNSYS simulation, machine learning and genetic algorithm (GA). Simulation for the entire winter operation of the solar space heating system is conducted in TRNSYS, and a database with various combinations of the design variables are generated, based on which an artificial neural network (ANN) is constructed to capture the mapping of the design variables and the system performance indicators. After proper training and validation, the ANN model with satisfactory forecasting precision is utilized as the objective function for optimizing the system. GA is employed for searching the solutions of the multi-objective optimizations. This data-driven approach combining ANN and GA is helpful to achieve the optimal solutions. For the solar space heating system, the CO2 emission reduction can benefit most from the enlargement of the solar collector area and the TES tank volume, while the payback period reaches its minimum when both the solar collector area and the TES tank volume are small. By comparing single-objective with multi-objective optimizations, it is found that the single-objective optimization cannot reveal the interactions among the CO2 emission reduction, annualized life cycle cost (ALCC) and payback period (PBP) and that the optimization focusing on a single objective probably leads to apparent defects and inapplicability in reality. Better balance among the CO2 emission reduction, ALCC and PBP can be achieved from the Pareto optimums of the multi-objective optimization rather than the single-objective optimization. According to the TOPSIS evaluation, the most appropriate design scheme is obtained from the multi-objective optimization and has the potential to reduce the carbon emission by 5480.6 kgCO2eq/year while the ALCC and payback period are only 33.40 ¥/(m2·year) and 3.70 years, respectively.

Utilization of biodegradable novel insulating materials for developing indigenous solar water heater for hill climates

Conventional flat plate collector based solar water heating systems use glass or ceramic wool as insulating materials to minimize the heat losses. The utilization of these inorganic insulating materials, is associated with risk in the industrial workplace activities, manufacturing, and installation depending on the exposure to the material. Thus, it is important to use and develop biodegradable organic insulating materials which are easily available, low cost and environment friendly. This study presents the design and fabrication of a flat plate collector solar water heating system using biodegradable forest and agriculture wastes as insulating material. The utilization of pine needles and rice husk as thermal insulation for the fabrication of solar water heaters is the novelty of the study. The innovative solar water heater is tested under different outdoor climatic conditions. Maximum hot water temperatures between 52 °C and 55 °C were observed with an average efficiency of 52% and 57% with rice husk and pine needles as insulating materials respectively. Experimental analysis is performed using 40 mm, 60 mm and 80 mm pine needle insulation. The optimum pine needles insulation thickness is found to be 60 mm with a maximum hot water temperature of 64 °C for the indigenously developed flat plate collector based solar water heater for hill climates. Follow-up research areas are also identified.

Occupants’ on-demand control of individual heating devices in rural residential buildings: An experimental scheme and on-site study

A better understanding of actual heating demands is crucial for optimizing operational heating systems, because disparities between expected load and actual demand are key factors in inefficient heating system design, implementation, and corresponding energy loss. Additionally, the discrete, energy consumption-based billing systems applied to freestanding rural residential buildings encourages reductions in energy waste but produces spatially and temporally distinct heating patterns. Conventional heating systems have only basic controls and slow response times that cannot reflect actual user demand. Hence, this paper presents an experimental scheme for measuring room-wise heating demands, and thus, the actual heating demand patterns of rural residential buildings. A case study was conducted on a typical rural residential building in Beijing to validate the method’s feasibility. Real-world usage patterns were obtained using indoor environment sensors and independently-controlled heating devices that collected the operational parameters of each room over three years, in a long-term non-intervention study design. Clustering analysis and various indicators were used to characterize heating demand for each room: heating patterns, usage intensity, and temporal variation. In most case, the occupants heated only a few rooms, rather than the whole building. These results have potential real-word implications for predicting occupant heating behavior and energy conservation.

Design and thermo-energetic evaluation of a solar building heating system

This paper presents the design, construction and thermo-energetic evaluation of a solar building heating system consisting of a double-pass counter-current solar air heating collector with porous matrix and a water-bed heat storage unit connected to a prototype building located at the National University of Salta, Argentina. The experimental study determined that the solar collector has an average daily efficiency of 37 % while the storage unit has an average daily efficiency of 38 %. The overall daily efficiency of the complete system is 18 %. During the test period, the night-time discharge of the storage unit ensured that the temperature of the room to be heated was always above 20 °C when the outside temperature was between 10 and 15 °C.

Study of the thermal characteristics of the aluminum radiator ROYAL Thermo Evolution

The use of aluminum radiators in heating systems began with the foreign companies products such as Fondital Group, Global Radiatori, Ferroli, etc. There are now Russian aluminum radiators companies that adhere to European standards, for example ROYAL Thermo, Rifar. The thermal characteristics of radiators are usually specified by the manufacturer. However, they are not always confirmed in practice. This is due to the fact that radiator connecting method is not taken into account. In some technical data sheets, the power reduction factors are given depending on the difference between the average coolant temperature and the air temperature in the room. Therefore, the study of the influence of aluminium heating appliances connecting on its thermal characteristics is an actual task. The article presents the results of research of radiator of the ROYAL Thermo Evolution type, it was made on request from company specialising in heating systems design. It was found that the actual thermal power of one section varies in the range of 135 … 225 W, depending on the connection method of the radiator, the thermal power of the section declared by the manufacturer corresponds only to the diagonal «top-bottom» connection, the thermal power of the eight-section radiator with one-sided «top-bottom» connection is 12% higher than with a diagonal one. Studies show, when designing heating systems, it is necessary to take into account the connection method and the number of device sections.

Evaluation of thermal performance of air source heat pump heating system based on electricity equivalent

Thermal performance assessment and optimization for energy conversion and utilization systems are of high significance in building energy efficiency. Generally speaking, the evaluation of actual thermodynamic system performance is mainly based on the First law of thermodynamics, with emphasis on the quantity of energy consumption, while ignoring the energy quality. Thus, it results in a one-sided evaluation in the analysis of system energy saving. In this paper, the electricity equivalent is used to analyse and evaluate the air source heat pump heating system under the different working conditions. Moreover, the dynamic thermal performances of three typical space heating devices (radiator, fan coil, and radiant floor) are investigated and compared by weighing both energy quantity and quality. The results show that the COP of radiator, fan coil, and radiant floor are 3.00, 3.82, and 4.76, and coefficient of energy quality are 48.32%, 51.43%, and 50.57%, respectively. However, the robustness of its thermal performance is lower than that of radiator and fan coil. This work can provide reference for energy systems assessment and guidance for practical design of building heating systems.

ИССЛЕДОВАНИЕ ФИЛЬТРОКОМПЕНСИРУЮЩЕЙ ФУНКЦИИ МНОГОФУНКЦИОНАЛЬНОГО ИНТЕГРИРОВАННОГО ЭЛЕКТРОМАГНИТНОГО КОМПОНЕНТА В СОСТАВЕ СИСТЕМЫ ИНДУКЦИОННОГО НАГРЕВА

Relevance The need for computer simulation is due to the modes of operation of induction heating systems and the high cost of the element base. This avoids the cost of expensive components. The use of a multifunctional integrated electromagnetic component is justified by the cost of individual discrete components that make up the induction heating system, as well as by the provision of the functionality of filter compensating devices. The use of a multifunctional electromagnetic component makes it possible to achieve a reduction in the resource intensity of the circuit, its cost, and to increase the reliability of the device. Aim of research This article discusses the design of an induction heating system with the function of a filter-compensating device, made on the basis of a multifunctional integrated electromagnetic component for an induction heating system that implements the technology of locally associated heating of an extended pipeline. The main task is to determine the electrical circuit of the filter-compensating device operating as part of an induction heating system of locally associated heating and the analytical calculation of the parameters of a multifunctional integrated electromagnetic component. Research methods In this study, the following methods were used: patent review, study of scientific literature, computer simulation performed in the ELCUT 6.4 software package. Results The authors have developed a scheme of an induction heating system with the function of a filter compensating device based on a multifunctional integrated electromagnetic component for an induction heating system that implements the technology of locally associated heating of an extended pipeline using functional integration methods. A study was made of the technology of locally associated thermal impact on an extended pipeline. In the ELCUT 6.4 software package, a computer model of the system was developed, and the efficiency of the filter-compensating device during the heating process was evaluated. As a result of the simulation, the characteristics of the magnetic field of the system were obtained and the thermal problem was solved, demonstrating the effectiveness of the technology of locally associated heating.

Visual design of heating systems

Visual design of heating systems

Integration of Phase Change Material in the Design of Solar Concentrator-Based Water Heating System.

Indonesia has been blessed with excellent solar heat distribution, which can be used as renewable energy to heat water. Various technologies have been developed to utilize these inexhaustible thermodynamic resources, in the form of photons arrays, converted into concentrated heat for daily use, i.e., solar water heater. This renewable-based water heating system can provide significant energy efficiency, benefit the environment, and reduce energy use costs. This experimental study attempts to harvest the energy from the sun using a cylindrical through collector (CTC) type solar concentrator. The CTC was made of the solar reflective film (SRF) affixed to concentrator collector surfaces which was then mounted on an adjustable angle frame of the concentrator collector support. The heat generated from the concentrator was stored in water, and phase change material is embedded in the system to retain the heat longer. The research was carried out in Langsa City, Aceh, Indonesia. The results showed that water heaters using CTC systems could produce 16 L of hot water retained at 40–60 °C for four hours. With the addition of beeswax, the water temperature of the same capacity can be maintained at 40–60 °C for around 5 h. This technology demonstrated an excellent result that produces as much as 60 L of water per day, increasing solar thermal energy efficiency. This technology presented a great potential for replication or even for further development on an industrial scale.

Design and Parametric Investigation of an Efficient Heating System, an Effort to Obtain a Higher Seasonal Performance Factor

The present work introduces an innovative yet feasible heating system consisting of a ground source heat pump, borehole thermal energy storage, an auxiliary heater, radiators, and ventilation coils. The concept is developed by designing a new piping configuration monitored by a smart control system to reduce the return flow temperature and increase the temperature differential between the supply and return flows. The radiators and ventilation heating circuits are connected in series to provide the heat loads with the same demand. The investigation of the proposed model is performed through developed Python code considering a case study hospital located in Norway. The article presents, after validation of the primary heating system installed in the hospital, a parametric investigation to evaluate the effect of main operational parameters on the performance metrics of both the heat pump and the total system. According to the results, the evaporator temperature is a significant parameter that considerably impacts the system performance. The parametric study findings show that the heat pumps with a thermal capacity of 400 kW and 600 kW lead to the highest heat pump and total seasonal performance factors, respectively. It is also observed that increasing the heat pump capacity does not affect the performance indicators when the condensation temperature is 40 °C and the heat recovery is 50%. Moreover, choosing a heat pump with a smaller capacity at the heat recovery of 75% (or higher) would be an appropriate option because the seasonal performance values are not varied by changing the heat pump capacity. The results reveal that reducing return temperature under a proper parameters selection results in substantially higher seasonal performance factors of the heat pump and total system. These outcomes are in-line with the United Nations sustainable development goals including Sustainable Cities and Communities.

Adjustments to the indicators of the heating and cooling degree-days for regions of the Republic of Uzbekistan

This paper identifies the indicators of the calculated heating and cooling degree-days for the territory of Uzbekistan. The revealed values of the maximum and average daily outside air temperature were taken into account based on the collection, processing and analysis of the latest archives of climatic data. These data was obtained from open sources of weather stations, suitable for servicing scientific data, in order to enter adjustments to forecasts in the design of heat and cold supply systems in buildings and structures, which, in turn, mitigate the effects of climate change.

Nonlinear heating system of modular-trigger and platform furnaces for firing bulk materials

The design of the suspended nonlinear heating system of modular-trigger and platform furnaces for firing vermiculite and other bulk materials is considered. Previously, the design of linear heating systems did not provide homogeneous heating of thermographed materials, the material in the clutch zones suffered sufficient thermal energy. In addition, overheating of the central zone increased the frequency of the impact of the heaters themselves, which affected the reliability of the furnace. The use of a nonlinear heating system has changed this distribution to the opposite. The power of the intuboxic heater exceeded the power of the central 1,2‒1,36 times depending on the ratio of the diameters of thin and thick (diameter of 4 mm) of the heaters. At the same time, not only their electrical power increased, but the heat radiation streams, falling onto the surface of the supply, which led to an increase in the temperature of the material being processed. The obtained values of the temperature of the vermiculite grains in the fitted zones of the firing module exceed the temperature of the vermiculite in the central zone by 26 %, while it is sufficient for high-quality material intimidation. Due to the use of nonlinear heating system, temperatures were redistributed on heated surfaces in favor of relatively cold previously intuition zones: the heat picture has changed to the opposite, that is, the cold cloth zones have become relatively hot. Ill. 8. Ref. 14.

Information model development for the quality assurance of technical equipment in small buildings

Ensuring energy quality, i.e. compliance with specified or standardised energy performance indicators of buildings over the entire life cycle, can reduce the climate impact of the building sector. In this work, the causes for quality deficiencies in small building services installations as well as the structure of actors interacting with building services were analysed. On this basis, we developed a solution approach in the form of an information model including a catalogue of all requirements and the necessary content to address and improve the quality assurance of HVAC in small buildings. This information model will serve as the basis for future digital tools that can perform (partially) automated heating load calculations and the design of heating systems, improve installation logistics and installation quality through providing information and the necessary processing, and enable improved hydraulic balancing and control.

Optimization design and operating parameters of induction heat-ing system for hardening

The paper deals with the problem of optimizing the design and operating parameters of an induction heating system for surface hardening of a steel stepped shaft. The problem of optimal design of an inductor is formulated based on a nonlinear two-dimensional numerical model of coupled electromagnetic and temperature fields, developed in the ANSYS Mechanical APDL software. Alternance method of parametric optimization of systems with distributed parameters is used to optimize induction hardening system. MATLAB software has been used for developing parametric optimization subroutine, which was incorporated into the numerical ANSYS model to simulate a process of induction heating. Commonly used a multi-turn solenoid-style coil fabricated from rectangular copper tubing has been used as a hardening inductor. Besides that, an application of profiled copper turns has been investigated. Optimization of induction hardening system described above allows one to substantially improve heating uniformity and enhance metallurgical characteristics of as-hardened stepped shaft. Localized temperature surplus at an upper diameter shoulder has been minimized. At the same time, sufficient austenitization in the fillet area near stepped region (diameter transition) has been obtained.

Design of a solar district heating system with seasonal storage in Italy

The residential sector is responsible for 26% of final energy consumption in the European Union. A key strategy to reduce household fossil fuel use is solar district heating with seasonal thermal energy storage. Although this technology has been widely applied in Northern Europe (Sweden, Denmark, and Germany), it has not been implemented in Italy. This research presents a new numerical tool, and applies it to the REPLICATE project in the Italian city of Florence, which is financed under the Horizon 2020 Smart Cities and Communities initiative. Our novel tool, which is based on a dynamic model coupled with the finite element method, has been developed to guide the design of the district heating plant and obtain a reliable estimation of performance, notably storage heat losses. The overall aim is to reduce the prediction inaccuracies that have characterized past projects. The final dynamic model is implemented in TRNSYS, and makes it possible to select the main plant parameters and define control strategies. It is linked to a detailed heat transfer model developed in COMSOL Multiphysics®, which can calculate storage heat losses and determine the optimal thickness of insulation material. Our in-depth parametric study determined the optimal volume of the hot water tank to be 3800 m3, and the size of the solar field to be 1000 m2. We also evaluated the effectiveness of the addition of a water–water heat pump. This analysis found that it is a crucial component as it can increase storage capacity and improve the performance of solar collectors by up to 124 MWh. Our results indicate that with an optimized configuration, the solar fraction of the system can reach up to 44%.

Development of a physical hydraulic modelling tool for District Heating systems

Network hydraulics play a major role in the design and operation stage of District Heating (DH) systems, considering further hydraulic complexities expected in the near future. This paper presents a mathematical solution procedure that computes the network hydraulics, tailored as unique to the principal basis behind the branched type of DH networks. The procedure makes use of simple input data (i.e., pipe-node list) to obtain the mathematical description of the network layout via detection algorithms for the incidence and the loop matrices (the pseudo-code given). The matrix-based solution procedure was formulised to detect the network flow and pressure distributions either by use of the Newton-Raphson or genetic algorithms, based on the conservations of mass and energy. The problem formulation was maintained as correcting the end-user flow rates that satisfy the energy conservation throughout the closed loops of the network, which sped up the convergence to a solution. The developed model was used in a case study consisting of 220 × 2 pipe segments (supply and return) and 214 end-users, the results being obtained in 35.5 s via the Newton-Raphson algorithm. Despite the sensitivity analysis, the genetic algorithm was found to have premature convergences under various trials.

Optimal design and integration of multiple-function solar water heating systems based on a co-adaptive matchmaking method

Many existing optimal solar-based hot water system design methods do not quantitatively consider the impact of energy mismatching, which leads to the overestimation of system performance and misleads the optimal design of the system. For addressing such mismatching problems, a solar-based hot water system optimization design method based on real-time energy balancing and co-adaptive matchmaking is proposed. It consists of three main parts: (1) establish a simplified solar hot water system model based on the real-time energy balance to simulate the dynamic energy performance of the system; (2) propose a co-adaptive matchmaking optimization method to minimize the energy mismatch between the supply and demand sides of the system; and (3) identify the scheme with the minimum life-cycle total cost as the optimum design. A multiple-function solar water heating system for the domestic hot water supply, space heating and air conditioning of a kindergarten building in Beijing was optimized based on the proposed optimization method. It was found that the energy mismatch degree between the supply and demand sides can be greatly reduced and leading to a maximum life-cycle saving cost up to 20.13% in the concerned case.

Influencing factors on thermal comfort and biosignals of occupant-a review

Thermal comfort has become one of the most important factors to be considered for the working efficiency and health of occupants in an indoor space. In addition, it is considered in the design of heating, ventilation, and air-conditioning systems for the management of building energy. In this study, the key factors influencing thermal comfort are briefly discussed, such as air temperature, air velocity, radiant temperature, relative humidity, insulation of clothes, and metabolic rate. These factors act in a complex manner, affecting people and causing physical and psychological changes. Also, human physical changes have a significant impact on the human body, including skin temperature, heart rate variability, and electroencephalogram measurements, and are modified by the surrounding thermal environment. In this article, the factors influencing thermal comfort and biosignals of humans are discussed, and recent related studies are introduced.

COMSOL Simulation for Design of Induction Heating System in VULCAN Facility

The experimental facility VULCAN was setup to study the fuel-coolant interaction (FCI) phenomena in a postulated severe accident of light water reactors. The heating system is important for the facility to prepare molten material in a crucible. This article is concerned with the design of the heating system, which applies electromagnetic induction heating method. The COMSOL code was employed to simulate the induction heating characteristics of a graphite crucible under different current and frequency of the work coil (inductor). Given a frequency, the relationship between the crucible’s average temperature and the inductor’s current is obtained, which is instrumental to select the power supply of the induction heating system. Meanwhile, the skin effect of induction heating is analyzed to guide the choice of frequency and inductor of the heating system. According to the simulation results, the induction heating system of frequency 47 kHz is suitable for the experiment, with a good agreement in temperature between the measured and the predicted.