Heating System In Winter Research Articles

Dynamic performance forecast analysis of MHP-PV/T-IDXSAHP system during heating season

MHP-PV/T is a novel PV/T with phase change heat transfer, uniform flow of working medium and good anti-freeze performance. The excellent year-round performance of MHP-PV/T has been demonstrated in previous studies and is more suitable for winter heating in northern China. In this work, we further combine MHP-PV/T with dual source heat pump to form an experimentally validated indirect expansion-solar assisted heat pump (IDX-SAHP) system and simulates the overall performance of the heating system in winter based on TRNSYS in Lanzhou, China. The component type50b of TRNSYS was modified to make it closer to the actual results of MHP-PV/T. Research shown that the thermal efficiency of MHP-PV/T heat pump system can be maintained well throughout the heating season at the SAHP/ASHP switching temperature is 7 ℃ in winter. The net system energy efficiency ratio (NSEER) during heating season is range from 3.28 to 5.42, which can achieve highly efficient and low cost heating. For this system, the photovoltaic power generation is sufficient to meet the operation of three water pumps. By connecting surplus electricity to the grid, a total of 1806.25 ¥ of electricity revenue can be obtained around the year. The PEUR of the system is 72.26 %, the DPP taking 5.133 years, and the annual CO2 emission reduction is 13486.5 kg. Significant energy, economic, and environmental benefits of the system. This study demonstrates the application prospects of PV/T heat pumps and provides a reference basis for subsequent research on MHP-PV/T heat pump systems in cold regions.

DESIGN AND IMPLEMENTATION OF A HOT WATER HEATING SYSTEM

The heating system in winter is very necessary, especially in cold areas, and there are several ways, including the use of fuel, and because of the increase in the use of fossil fuel energy and the high cost, and the risks of toxic gases resulting from fuel combustion, and this negatively affects human health. Where a heating system was designed based on the domestic heater instead of a boiler and the use of a radiator heat exchanger, a fan that enhances the air temperature distribution system in the room, and a water pump to push water into the system with an electronic control, a system equipped with digital sensors to measure the temperature. After operating the system, the temperature of the hot water ranged from 80°C to 90°C, and the atmosphere inside the test room ranged from 17°C, the finding are good from where of energy consumption and heating in a record time at an average of 25.8°C.

Modeling the Household Electricity Usage Behavior and Energy-Saving Management in Severely Cold Regions

Accurate simulation and prediction of occupants’ energy use behavior are crucial in building energy consumption research. However, few studies have focused on household energy use behavior in severely cold regions that have unique energy use patterns because of the low demand of cooling in summer and the use of central heating system in winter. Thus, we developed an agent-based model to simulate the household electricity use behavior in severely cold regions, according to data for Harbin, China. The model regards apartments, residents, household appliances, and energy-management departments as agents and generates the household electricity consumption with respect to time, temperature, and energy-saving events. The simulation parameters include basic information of the residents, their energy-saving awareness, their appliance use behaviors, and the impact of energy-saving management. Electricity use patterns are described by decision-making mechanisms and probabilities obtained through a questionnaire survey. In the end, the energy-saving effects of different management strategies are evaluated. The results indicate that the model can visually present and accurately predict the dynamic energy use behavior of residents. The energy-saving potential of household electricity use in severely cold regions is mainly concentrated in lighting and standby waste, rather than cooling and heating, since the cooling demand in summer is low and the heating in winter mainly relies on central heating system of the city, not on household electricity appliances. Energy-saving promotion can significantly reduce the amount of energy waste (41.89% of lighting and 97.79% of standby energy consumption), and the best frequency of promotional events is once every four months. Residents prefer incentive policies, in which energy-saving effect is 57.7% larger than that of increasing electricity prices. This study realized the re-presentation of the changes of energy consumption in a large number of households and highlighted the particularity of household energy-saving potential in severely cold regions. The proposed model has a simple structure and high output accuracy; it can help cities in severely cold regions formulate energy-saving management policies and evaluate their effects.

The Impact of “Coal to Gas” Policy on Air Quality: Evidence from Beijing, China

Air pollution has become an increasingly serious environmental problem in China. Especially in winter, the air pollution in northern China becomes even worse due to winter heating. The “coal to gas” policy, which uses natural gas to replace coal in the heating system in winter, was implemented in Beijing in the year 2013. However, the effects of this policy reform have not been examined. Using a panel dataset of 16 districts in Beijing, this paper employs a first difference model to examine the impact of the “coal to gas” policy on air quality. Strong evidence shows that the “coal to gas” policy has significantly improved the air quality in Beijing. On average, the “coal to gas” policy reduced sulfur dioxide (SO2), nitrogen dioxide (NO2), particulate matter smaller than 10 µm (PM10), particulate matter smaller than 2.5 µm (PM2.5) and carbon monoxide (CO) by 12.08%, 4.89%, 13.07%, 11.94% and 11.10% per year, respectively. We find that the “coal to gas” policy is more effective in areas with less energy use efficiency. The finding of this paper suggests that the government should continue to implement the “coal to gas” policy, so as to alleviate the air pollution in Beijing, China.

Integration of a heat exchanger on the supply air with the ground-source heat pump in a passive house – case study

A ground-source heat pump (GSHP) system designed to cooperate with a low temperature heating system and hot water production was installed in a new passive house nearby the city of Poznan (Poland). The paper describes an integration of the GSHP system with a heat exchanger on the supply airflow in order to recover the waste heat from outside (fresh) ventilation air and store it in the ground during summer, as well as to heat the supply air in winter what prevents the recuperator from freezing. Analytical calculations to evaluate the energy, economy and environmental benefits of supplying the low heat reservoir with heat from fresh air were made. Chilled supply air compensates the heat gains from building and is exhausted, simultaneously overcoming a part of the cooling loads by using mechanical ventilation system. Heat taken in the heat exchanger by the glycol mixture is used in the evaporator of the heat pump, which produces hot water with increased energy efficiency – increased coefficient of performance (COP). After that glycol mixture is supplied to the ground. In the case of stagnation of the heat pump, glycol mixture exiting the heat exchanger is directed to the ground, where part of the delivered waste heat is stored. The results of calculation experiment indicated that heat recovered from the supply ventilation air during summer is increasing the Seasonal Performance Factor (SPF) of the heating system in winter, consequently significant energy savings can be achieved, what is a part of the idea of the Sustainable Development. Based on the simulations it has also been demonstrated that the proposed technical solution has a high application potential for micro and macro scale installations using GSHP.

Practical performance of a small PTC solar heating system in winter

The active solar house-heating in winter is a novel technology that is eco-friendly and economical. The performance of a small solar heating system composed of parabolic trough collector (PTC) and ventilation pipelines has been experimentally investigated in the current study. With an automatic solar-tracking device, the system adopted a PTC device of aperture area 2.407 m2. The air stream was heated in the tube collector and then driven into the test room. By examining the heat gain of the air stream passing through the PTC as well as the temperature distribution of the indoor air, the working characteristic of the solar-heating system in winter was evaluated practically. The experimental results showed that for the generally-insulated room that was located in 39.87°N latitude, the daily solar heating time reached to 6–7 h, and the thermal efficiency of the PTC device was above 60%. Supposing the heat loss is reduced effectively along the outdoor pipelines in the future, such active solar heating system will be a promising heating technology in regions that are not far north on the earth.

Application of Solar Air Collector and Floor Air Supply Heating System in Winter

In this paper, The utility model relates to a heating system which is composed of a traditional solar air collector, a floor air supply and a phase change heat storage air duct, which is used for heating the room in winter. Using Fluent software to simulate the whole system in winter. The results show that this system conforms to the standard of winter heating. The system needs to add an electric heating auxiliary heat source, which is used to heat the room in the night or rainy day.

Reduced LS-SVM을 이용한 지역난방 동절기 공동주택 난방부하의 모델링

A model of apartment heating load in a district heating system could be useful in the management and utilization of energy resources, since it could predict energy usage and so could assist in the efficient use of energy resources. The heating load in a district heating system varies in a highly nonlinear manner and is subject to many different factors, such as heating area, number of people living in that complex, and ambient temperature. Thus there are few published papers with accurate models of heating load, especially in domestic literature. This work is concerned with the modeling of apartment heating load in a district heating system in winter, using the reduced least square support vector machine (LS-SVM), and with the purpose of using the model to predict heating energy usage in domestic city area. We collected 23,856 pieces of data on heating energy usage over a 12-week period in winter, from 12 heat exchangers in five apartments. Half of the collected data were used to construct the heating load model, and the other half were used to test the model`s accuracy. The model was able to predict the heating energy usage pattern rather accurately. It could also estimate the usage of heating energy within of mean absolute percentage error. This implies that the model prediction accuracy needs to be improved further, but it still could be considered as an acceptable model if we consider the nonlinearity and uncertainty of apartment heating energy usage in a district heating system.

The development of a natural heating technology for constructed wetlands in cold climates

Composting of different ratios of pig manure to reed straw was studied to be a natural heating technology of constructed wetlands (CWs) in winter. Among the mixtures of pig manure and reed straws in different ratios, the pure pig manure was the most suitable compost material for the heating system of CWs in cold climates and its life expectancy was about 40 days. The one-year validation test in real-scale CWs with composting of pure pig manure as natural heating system in winter proved that the heating system of CW with pure pig manure as compost material can work effectively and enhance the pollutants removal rate in winter. The water temperatures inside the CW with heating system in winter (15.7–21.7°C) were higher than that of CW without heating system (9.2–13.6°C). The mean areal load reduction of TN and of NH3-N in winter of CW with heating system was 1.008g/m2/d and 1.08g/m2/d, which was about 120% more than that of CW without heating system.

Coupling between Geothermal Energy and Solar Energy for Creation of New Energetic System &quotProduction of Electricity and Hydrogen&quot in Intelligent Buildings

paper describes a new technique coupling between two mains parts which are geothermal energy and solar energy in order to product electricity and to create a comfort in intelligent buildings. The first parts consists extraction of heat water from geothermal source at the temperature of 95°C (Guelma), for injecting it in solar panels in order to increase the temperature of the water until 600°C for production of electricity and hydrogen. Moreover, the selection of geothermal energy is for only two reasons. In one hand; is to generate heating system in winter and cooling system used by absorption machine in summer. In the other hand is to develop of the local production of electricity and hydrogen at the same time. Finally the principal objective is to provide energy efficiency in intelligent buildings and distribution of electricity in the grid. Another aim is to minimize loads during production of electricity.

Artificial neural network analysis of the performance characteristics of a reversibly used cooling tower under cross flow conditions for heat pump heating system in winter

This study deals with predicting the performance characteristics of a reversibly used cooling tower (RUCT) under cross flow conditions for heat pump heating system in winter using artificial neural network (ANN) technique. For this aim, extensive field experimental work has been carried out in order to gather enough data for training and prediction. After back-propagation (BP) training combined with principal component analysis, the three-layer ANN model with a tangent sigmoid transfer function at hidden layer with 11 neurons and a linear transfer function at output layer was obtained. The predictions agreed well with the experimental values with a satisfactory correlation coefficient in the range of 0.9249–0.9988, the absolute fraction of variance in the range of 0.8753–0.9976, and the mean relative error in the range of 0.0008–0.54%, moreover, the root mean square error values for the ANN training and predictions were very low relative to the range of the experiments. The results reveal that ANN model can be used effectively for predicting the performance characteristics of RUCT under cross flow conditions, then providing the theoretical basis on the research of heat and mass transfer inside RUCT, which is important for design and running control of the RUCT system.

The Study of Cooling Water Waste Heat Recovery in Chemical Plant by Heat Pump System

A large number of cooling water exists in chemical plant, use water source heat pump and lithium bromide absorption heat pump system to achieve water cooling instead of cooling tower, at the same time, extract heat for building cooling and heating. Respectively introduced the summer cooling system and winter heating system, and a feasibility analysis was carried out. The conclusion is get: water source heat pump system and lithium bromide absorption heat pump system for cooling water waste heat recovery is certain feasibility; the environment optimization can be achieved in chemical plant, at the same time, energy conservation and emission reduction is realized.

Analysis of indoor humidity environment in Chinese residential buildings

A high or low humidity environment is related closely to not only many health problems, but also has great influence on the construction durability and energy consumption. It is very important to control humidity level, in order to achieve a healthy and comfortable indoor environment. However, various problems of the air humidity in inhabited dwellings are not yet taken serious consideration in China. Moreover, there is hardly any information available regarding the actual humidity environment in Chinese residential houses. For this reason, it is difficult to select appropriate moderate moisture strategies to maintain a harmonious indoor humidity level. The current authors carried out a field measurement survey on indoor thermal environment in nine Chinese cities. Based on this investigation, the purpose of this present study is to develop a database of actual indoor humidity conditions for moisture moderate design, through which the characteristics of indoor humidity environment in Chinese residential houses can be identified and clarified. The results demonstrated that the indoor humidity level is too low with the relative humidity falls below 20% in some cities where residences equipped with central heating system in winter. On the other hand, indoor humidity is very high with the relative humidity beyond 80% in some cities where residences have inadequate heating and high outside humidity ratio in winter. The severe indoor humidity environment indicated that the moisture level in the residential houses of China should be mitigated and controlled in order to achieve a sustainable and healthy indoor environment.