Design And Simulation Of Sewage-Source Heat Pump System With Multilevel Sprinkling Heat Exchanger

A new sewage-source heat pump system is presented based on the sewage treatment of a drug plant in Harbin. The system is designed for bringing the heat from the sewage that has been treated to the fore-sewage in order to meet the request of the sewage temperature, especially presents the suitability in cold district and cold months.In order to improve the previous system for being adjusted better, the multi-grade sprinkling heat exchanger is divided to three parts that are connected to three compressors each. The parameters for sprinkling equipment are calculated in detail. The larger heat transfer coefficient leads the worse heat transfer. Modeling is presented with the software MATLAB. The curve of the compressor sample is fitted. The models of condenser, expanding valve and evaporator are established by using subarea concentrated parameters method and concentrated parameters method. Conservation of mass law, conservation of momentum law and conservation of energy law are used with the Sequential Modular method for modeling.The performance of the sewage-source heat pump system with multi-grade heat exchanger is simulated. Based on the simulation results, the structural parameter is revised in detail. The effects how the systemic parameters such as sewage flow, temperature of sewage at the inlets of condenser and evaporator impact on the systemic performance are analysis. When the systemic conditions change a lot, the regulations and static performance of system are studied.The system is changed based on the result of simulation in order to improve the performance. The three systems run with different evaporate temperature and the way of every evaporator connected into each system is changed. The performance of the new system that is improved is simulated and the optimized system is given.