Study On Characteristics Of Direct Expansion Heat Pump System For Solution Freezing Regeneration

This paper based on the difficulty and the problem of high energy consumption of the inverse when cooling tower in winter antifreeze solution regeneration, frozen regeneration solution scheme is put forward, and design to build a set of direct freezing regeneration system of heat pump solution device.Through direct freezing regeneration system of heat pump solution device the experimental study on the solution of frozen regeneration process.Through the understanding of the solution principle of freezing and melting ice, in the solution to the system of frozen regeneration process and tube inside and outside heat transfer characteristics in the process of melting ice and the concentration of the solution, the dynamic change of temperature are analyzed;From the fundamental equations of fluid mechanics, the thermal resistance network solution is established the dynamic model of the heat exchanger in the freezing and thawing process, on the basis of the combined heat pump cycle simulation model is established the whole straight frozen regeneration system dynamic simulation model of heat pump solution, and using MATLAB software to write the corresponding simulation program, through the experimental data and model, comparing the simulation results verify the accuracy of the model.Using the simulation model, the paper direct freezing expansion heat pump solution regeneration system of internal parameters (evaporation pressure, refrigerant flow, compressor power, etc.) and external parameters (solution concentration, solution temperature, the ice thickness, etc.) along with the change of time characteristics are analyzed, based on the initial concentration, solution temperature of solution effect the regeneration performance of the system are discussed in this paper, obtained the following results:From the inverse solution concentration on the winter cooling tower with the runtime security perspective, select the concentration of 15% at the end of sodium formate solution regeneration.By using the system simulation model simulation initial temperature 10 ℃, the initial concentration of 8%,10% and 12% respectively of sodium formate solution of frozen regeneration process.Results show that the rise of the initial concentration of the solution can greatly shorten the solution freezing of recycling to the end of time, reduce the system energy consumption;And through to the initial concentration of 12%, initial temperature of 10℃ ,4 ℃ respectively,2 ℃ - sodium formate solution freezing process simulation calculation, found that initial temperature for the solution of sodium formate solution to reach the time at the end of regeneration and the impact of system energy consumption is small.