Research Of Running Modes And Economy For Direct Radiant Floor Heating System With Air-source Heat Pump

Direct radiant floor heating system with air-source heat pump is anew way of heating, which combines the air source heat pump technologywhich is energy saving and radiant floor with refrigerant directly heatingtechnology which is high heat transfer efficiency. This system caneffectively improve the heating efficiency, and because of its goodeconomical and comfortable, it can make the system widely used in urbanand rural residential building. In addition, the system can set differentwork conditions of room temperature and the start and stop timeaccording to the users, achieve good comfort and energy saving effect. Inthe paper, the system in a residential building was installed a model bysoftware TRNSYS. Compared with the actual measured data, it wasproved to be accurate. On this basis, this paper put forward to threerunning modes: running of all day on, running of daytime on andnighttime off and running of daytime off and nighttime on. Using themodel simulation in the three operating modes, it can compare theircomfort and economy of the pros and cons. The research of the paper can be a theoretical guiding significance for the application andpopularization of the direct radiant floor heating system with air sourceheat pump system. Research contents and conclusions are as follows:1. The mathematical models of the part of direct radiant floorheating system with air-source heat pump system and building heat loadwere set up.2. Based on the actual measured value for the heating system whichwas installed in a building, it is proved that in operating modes of runningof daytime on and nighttime off, indoor temperature can basically reach20℃during daytime and16℃during nighttime. Through the comparisonof the outdoor temperature, dynamic measurement and Simulation ofdynamic average indoor temperature, solar radiation, the instantaneousvalue of indoor dynamic thermal load and test phase of the system powerconsumption, analysis of the causes of errors, proved that the model canreplace the actual condition, and achieved good simulation effect.3. By using the system model to the three operating modes toachieve the dynamic indoor temperature, dynamic comfort, daily averagecoefficient of performance of the system, daily power consumption, itwas concluded comprehensive comparative analysis that, although therunning of daytime off and nighttime on was good in economy whenimplementing off-peak electricity pricing applications, the thermalcomfort was poor. On the basic condition of thermal comfort, running of daytime on and nighttime off is better than running of all day on. Whenusing a unified price or the price ladder, running of daytime on andnighttime off was better in economy. when implementing off-peak price,running of all day on was better in economy.4. It used annual cost to calculate and analyze economy of directradiant floor heating system with air-source heat pump in detail, andcompared with some common heating methods in initial investment cost,operating cost and annual cost. From the specific data, direct radiant floorheating system with air-source heat pump is in the middle among theother heating methods. From the consumption of primary energy, theenergy saving of several heating modes is calculated and analyzed, andthe results show that the energy saving of direct radiant floor heatingsystem with air-source heat pump is the best. Comprehensiveconsideration of economic benefits, environmental benefits, socialbenefits and energy efficiency, direct radiant floor heating system withair-source heat pump is a better heating mode.