| Solar-air source heat pump systems usually use dual heat sources to meet the needs of building hot water and heating,but currently solar-air source heat pump systems generally have imbalance of building heat demands and system heating energy supply due to regional and climatic differences.The imbalance in demand in terms of energy matching has led to the problems of large errors and inaccurate energy matching relationships in the energy supply research of the system that is usually used in static analysis.This paper builds solar-air source heat pump systems in Kunming and Shangri-La respectively.Experimental research has been conducted and the system transient heat balance model has been established,the applicability of the transient model in different weather conditions has been verified and analyzed.The dynamic analysis method is used to study the influence of environmental factors on the system heating-storage-heating room process,and the system energy consumption,building heat utilization rate and other indicators were evaluated,finally the heat of the system heating and building heat demand Matching relationship was derived.The main research work includes:?1?Experiments were carried out in solar-air source heat pump systems with evacuated tube solar collector and air source heat pump as dual heat sources for heating,and hot water storage tanks as heat storage devices were built in warm region?Kunming?and cold region?Shangri-La?,TRNSYS simulation model was established for the built system,and put forward related system evaluation indicators.Taking the physical heating building as the experimental object,the heat demand for hot water supply and cold heating season throughout the year was calculated,and the balance between system heating and building heat demand based on the system heating-storage-heating room process under transient heat balance model was established.The heating modes of the system in sunshine time and non-sunshine time are solar-heat pump dual heat source heating and heat pump single heat source heating respectively,and the heat flow of each part was determined by different modes.?2?Energy supply models for complex working conditions such as sunny weather,partly cloudy weather,rain and snow weather were established,and model verification for different weather conditions were carried out to evaluate the applicability of the model.The results show that the heating capacity of heat collectors,heat pumps,and building heat demand in sunny weather are the most stable,with an average relative error of less than 10%;short-term occlusion of the cloud cover under low water temperature in sunny and cloudy weather will cause the heating capacity of the collector,the relative error increases about 5.1%,and the actual heating capacity of the collector decreases;when the outlet water temperature of the collector is?45?,the cloud cover blocks the system heating cycle.The ambient temperature fluctuation in rain and snow weather is less than 5?.The main reason for the heating error of the air source heat pump is the reduction of the evaporation temperature.The relative error ranges of heating are 4.414.4%.The maximum error range of building heat demand is 4.2%.The verification under various working conditions shows that the main reason for the fluctuation of the system heating and building heat balance is the instantaneous changes in solar irradiance and ambient temperature.?3?An experimental analysis of the system's heating-storage-heating room process under instantaneous solar irradiance and ambient temperature fluctuations was conducted,and obtained the changes of environmental factors and system performance.The heating capacity of the collector is in the range of 3.0218.11 MJ,for every 1 m2 of effective heat collection area,the heating capacity of the heat pump needs to be increased by 5.75 MJ at the same time.For sunny weather and partly cloudy weather,the heating capacity of the collector increases by 5 MJ,The energy consumption of the heat pump is reduced by 0.54 kWh;the decrease in the ambient temperature during non-sunshine hours will cause indoor heat loads to increase by14.7%and 23.9%in warm area?Kunming?and cold area?Shangri-La?,respectively.?4?Combining with the annual energy consumption of the system and the heat utilization rate of the building,the matching relationship between the heating capacity of the solar-air source heat pump system and the heat demand of the building was calculated and analyzed,and the"full load characteristic of solar air-energy dual heat source-hot water heating"has 3 modes:collector can not meet the demand for hot water throughout the day Qc<Qw,collector can meet the demand for hot water throughout the day but not the heating demand during sunshine time Qw?Qc<Qssh,collector can meet the demand for hot water and sunshine time heating demand Qssh?Qc.The effective average heat collection area of heat collectors corresponding to the three modes of Shangri-La and Kunming and the average daily cumulative heating capacity of heat pumps required per unit building area are:1.Qc<Qw,effective heat collection area 2.352.72 m2,2.212.51 m2,heat pump heating capacity 6.426.87 MJ·m-2,4.154.63 MJ·m-2;2.Qw?Qc<Qssh,effective heat collecting area 5.116.05 m2,3.744.21 m2,heat pump heating capacity 3.954.48MJ·m-2,2.763.18 MJ·m-2;3.Qssh?Qc,effective heat collecting area>10.33 m2,>7.48 m2,heat pump heating capacity 2.993.33 MJ·m-2,1.692.17 MJ·m-2.The research work in this paper summarizes the matching relationship between the system heating capacity and building heat demand in the solar-air source heat pump system,and achieves the effective use of energy from the perspective of transient heat balance,provides a certain theoretical analysis value and practical technical application reference for the efficient and stable operation of the system. |
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