Performance Improvement Of Radiant Heating Terminal With Low Temperature Hot Water In Chongqing Rural Dwelling

Low temperature hot water radiation heating is proliferated in foreign countries, with its good thermal comfort property high energy efficiency, reduced building space occupation and lower impact on indoor decoration. This technology also makes the advantage of using low temperature heat source. The temperature of indoor air may rise relatively slower by using buried pipe of radiation heating, in comparison to a form of convective heating by using room air conditioner. This is attributed by the relatively longer temperature response time to fulfill the demand of indoor thermal comfort because of heat storage property of the building envelope. At the same time, under the background of the rapid development of new rural reconstruction and heated discussion of heating in winter in hot summer and cold winter zone, people's requirements on the indoor thermal environment and comfort are also significantly improved in rural buidings. We need to seek a healthy, comfortable, efficient, social environment friendly way of heating to solve the contradiction between bad present situation of living environment and human health requirements, the growing demand for heating and energy saving and emission reduction in China. Therefore, this paper takes the low temperature hot water radiant heating terminal as the research object and inspects its applicability and performance optimization in the Chongqing rural dwelling.Firstly, the paper carried out an experimental study on the low temperature hot water radiant heating system based on experimental platform. Compared the indoor thermal environment, temperature response speed, heating capacity and energy consumption of capillary floor radiant heating and hot water floor radiant heating under different water supply temperature(35?, 40?, 45? and 50?). The experimental results show that the indoor temperature can reach 16.0 ? under different conditions, and the indoor temperature distribution is uniform. At the start stage of the system, the indoor temperature rising speed is about 0.5-0.6 ? /h when the radiant heating terminal is capillary floor, and the indoor temperature rising speed is about 0.2-0.3?/h when the radiant heating terminal is hot water floor.Secondly, combination terminal is adopted to optimiza indoor air temperature response speed of low temperature hot water radiant heating, namely through the experiment study to compare the indoor thermal environment, temperature response speed, heating capacity and energy consumption of capillary floor radiant heating and capillary combination radiant heating(capillary floor radiant heating+capillary wall radiant heating), hot water floor radiant heating and hot water floor combination radiant heating(hot water floor radiant heating+capillary wall radiant heating) respectively. The experimental results show that under the same experimental conditions, temperature rising speed of capillary combination radiant heating is about 1.5-3 times of capillary floor radiant heating and temperature rising speed of hot water floor combination radiant heating is about 3-8 times of hot water floor radiant heating.Finally, used variance analysis to analysis the influence factors of water supply temperature, outdoor temperature and radiant heating terminal on indoor temperature rising speed. And based on experimental results, indoor temperature change rules and characteristics on each stage was fitted. Combined it with the indoor temperature response speed and unit energy consumption, the action schedule was obtained under the premise of meeting the basic requirements of indoor comfort of low temperature water radiant heating. It can guide the start and stop time setting, water supply temperature setting and selection of radiant heating terminal forms of air source heat pump low temperature hot water radiant heating system. This provides a reference for application of low temperature hot water radiant heating system in Chongqing rural area.