【作者】 王景刚；

【导师】 马一太；

【作者基本信息】 天津大学 ， 工程热物理， 2003， 博士

【摘要】 本文以自然工质热泵循环性能和地源热泵运行特性为研究对象，从工质和热源的角度，开展了资源与环境可持续发展的热泵基础理论研究和实验研究，重点研究和分析了CO₂地源热泵和R22地源热泵的基本特点和运行规律。主要研究内容包括：1．自然工质热泵循环性能分析对自然工质CO₂、氨、碳氢化合物、水作为热泵工质的特点进行了评价与分析，重点对CO₂跨临界热泵循环性能的主要特征和影响因素进行了理论分析和研究。提出了CO₂跨临界热泵循环主要工况参数的确定方法和原则，运用当量冷凝温度，对不同工质热泵的循环性能进行了分析比较，指出在中高温热泵应用领域，CO₂热泵可以取得和传统工质热泵相竞争的优势。通过对双级压缩带膨胀机CO2跨临界热泵循环的研究，探讨了旨在提高CO2跨临界循环热泵效率的途径与措施。开展了水压缩式热泵的理论研究，指出以水为工质的热泵循环，应采用三级或多级压缩的方式。对丙烷和异丁烷热泵的循环特征进行了理论分析与总结。2．地源热泵运行特性理论分析针对以土壤为热源和热汇的特点，运用热力学的方法，对R22涡旋压缩式地源热泵和CO₂地源热泵的运行变化规律进行了理论研究，提出了CO₂地源热泵机组型式的确定方法，研究和探讨了地源热泵运行参数和运行控制策略的确定方法，指出CO₂地源热泵宜根据气体冷却器进水温度进行压力控制和容量调节，并提出了具体的运行压力控制公式。根据CO₂热泵的实验结果，拟合出了CO₂压缩机等熵效率公式，对影响CO2热泵实验样机效率的因素进行了分析和研究。3．地源热泵实验研究建立起具有两眼120m深埋管井和4眼测温辅井的地源热泵实验装置，热泵机组采用R22涡旋压缩机，ARI标定工况制冷量为21.8 kW。实验系统工艺流程和数据采集与处理系统，可以满足不同季节、不同运行条件下的地源热泵实验要求。开展了R22地源热泵的冬季工况和夏季工况的运行特性实验研究，重点对地下温度场变化规律、地下埋管换热器特性和地源热泵系统循环性能的实验结果进行了总结和分析。<WP=4>4. 地源热泵模拟方法与模型验证在地源热泵运行特性理论研究和实验研究的基础上，依据圆柱源理论，建立起了变热流条件下，耦合地面热泵机组和地下埋管换热器特性的R22和CO₂地源热泵系统的模拟模型，该模型可用于地源热泵系统的逐时运行特性模拟和全年能耗分析。模型验证结果表明，模拟结果与实验数据具有较高的吻合程度，表明所建模型可用于地源热泵系统的方案规划、运行控制和全年能耗分析等方面。5．地源热泵运行特性模拟与能耗分析运用所建模型，对R22地源热泵系统的全年运行特性进行了模拟研究，开展了不同土壤、不同回填材料、不同埋管长度和不同负荷容量比例的地源热泵系统的模拟研究和能耗分析，指出地源热泵的节能和安全可靠运行，必须建立在经过有效性和可靠性验证的模拟基础之上。CO2地源热泵的模拟研究结果表明，自然工质CO2应用于以土壤为热源的热泵系统时，完全可取得和R22地源热泵相接近的运行节能效果。更多还原

【Abstract】 The dissertation investigates the coefficient of performance (COP) of heat pump with natural refrigerants and operating characteristics of the ground source heat pump theoretically and experimentally. The study considers the influence of refrigerants and heat source from the view of point of sustainable development. The work focuses on the research on the basic characteristics and performance of the heat pump using CO2 and R22 as working fluids. And the main contents are as following.1. Research of the coefficient of performance of the heat pump with natural refrigerants The properties of natural working fluids such as carbon dioxide, ammonia, hydrocarbon and water as heat pump refrigerants are analyzed and evaluated. The further analysis on basic properties of the coefficient of performance of CO2 transcritical cycle heat pump and the main effect factors are presented. The methods and the principles to confirm the main operation condition of CO2 transcritical heat pump cycle are proposed. Through comparisons on the coefficients of performance of heat pumps with different refrigerants based on the equivalent condensation temperature, the analysis indicates that there are some advantages for CO2 heat pump to compete to the conventional refrigerant heat pump in the condition of the middle and high temperature application. Two-stage compression CO2 transcritical heat pump cycle with an expander is studied in order to find the ways and measures to improve the efficiency of the CO2 heat pump. Meanwhile the compression type heat pump cycle with water as a refrigerant is analyzed theoretically and the results indicate that the three-stage or multi-stage compression type may be a good option when the heat pump with water as a refrigerant is applied. The properties of coefficients of performance of heat pumps with propane and isobutene are summarized. 2. Analysis of the Operating Performance of the Ground Source Heat PumpAccording to the characteristics of the soil as the heat source and sink, the operation rules are studied on the ground source heat pump with scroll compressor and R22 as a coolant and the one with CO2 as a refrigerant based on the thermodynamics. The methods are brought forward and discussed to make certain the type of the CO2 ground source heat pump unit, the operation parameters and the control maneuvers of performance of the ground source heat pump. The analysis shows that the capacity regulation and the pressure control based on the inlet temperature of the gas cooler can be a better control method for CO2 ground source heat pump and the pressure formula for operation control is also proposed. According to the experimental results of CO2 heat pump, the correlation of isentropic efficiency of the CO2 compressor is given and the main factors that affect the efficiency of the prototype of the CO2 heat pump are analyzed.<WP=6>3.Experimental Research of the Ground Source Heat PumpThe experimental ground source heat pump system has been set up, which consists of two wells with U-tubes inserted into 120m deep boreholes and four assistant wells for temperature test. The cooling capacity of the heat pump unit with R22 scroll compressor is 21.8kW at the ARI standard condition. The technical maneuvers of the experimental system, the data acquisition and manage systems can meet the demands of the ground source heat pump experiments at different seasons and various operation conditions. Experiments on operation property of the ground source heat pump with R22 were conducted at the winter condition and the summer condition respectively. The experimental results on the change of ground temperature profile, the characteristics of U-tube ground heat exchanger and the coefficient of performance of the ground source heat pump cycle are analyzed and summarized in special. 4. Establishment and Validity of the Ground Source Heat Pump System ModelAccording to the column source theory and with the help of existing theoretical and experimental researches of the ground source heat pump, the simulat更多还原