| Heat source tower heat pump system is a high-efficiency and energy-saving cold-heat source design which can be used to get cold with high efficiency in summer and avoid no use of equipment and frost problem in contrast to air source heat pump in winter.lt is based on the full building heat load to design the heat source tower heat pump,so as to let the heat pump system run under less than 60% load in more than 80% running time.Entransy theory has been widely used in many areas including the heat exchange process, thermal power conversion process and the heat and mass transfer process and achieved great success.In order to match the best operation condition,the paper combined numerical simulation with experimental study to analyze the performance and optimization of heat source tower heat pump system in winter condition based on entransy theory.The paper verified the feasibility of the entransy theory to the heat source tower heat pump,derived the ralation formula bewteen the system entransy increase and energy ratio,established the math model of heat pump and set up the entransy-analysis model based on maths model.Build a heat source tower heat pump system experiment platform based on the established entransy-analysis model.the paper made simulations and experiment study of the relations between the operation parameters including compressor frequency,solution flow rate,air flow rate to find out that the relative error could not exceed by 15% verify the accuracy of the model according to the data of simulation and experiment.The results showed that the entransy increase changed oppositely to the energy ratio which is in agreement with the theoretical analysis. So the paper introduced the entransy as a new evaluation index of the system performance and contrast the effect of different operation parameters to system performance. The results showed the compressor,solution pump,heat water pump and fan play important roles in system performance.Based on major factors which have large effect on system performance, two kinds of schemes are used to optimize system operation.One is to change compressor frequency, solution flow rate, air flow rate and the other is to change compressor frequency, solution flow rate, water flow system. The author choosed the minimum value of system entransy increase as the evaluation index to achieve the best operation scheme and contrast the optimization operation with regular operation scheme to find out that scheme proposed in this paper has the biggest entransy increase rate of 25.1% and can save 28.5% energy at most. The results of this study provides a new way for the application and the reformation of heat source tower heat pump system. |
