Optimal Control Method With Variable Differential Pressure In Air Conditioning Chilled Water System Based On TRNSYS

The energy consumption of air conditioning system has a large proportion of the buildings’ energy consumption. The energy consumption of chilled-water pumps and chiller accounts for about 55% of the total energy consumption of central air conditioning systems. So, it is quite necessary to save energy consumption of air conditioning water systems. Optimal regulation and control of air-conditions water system has led an important role in energy saving implementation.The variable flow air conditioning chilled water system as the research object in this paper. To achieve the pump energy consumption reduction and efficiency improvement through the simulation to optimize the pressure setting value. Firstly building model is established by TRNSYS. The qualitative analysis shows that the correctness of the building model.Then through the pump logical relationship between the flow, head and impedance, the TRNSYS simulation platform is established. The TRNSYS simulation platform overcome the thermal performance of the system and neglect the hydraulic characteristics. Finally, through adjusting the valve opening and differential pressure setpoint in practical central air conditioning system. Measuring the actual data parameters. The feasibility of the simulation platform is verified by comparing of experimental data and simulation results. Because of the uncertainty of the adjustment of the valve opening and the pressure difference setpoint, the optimization method of the pressure difference between the supply and the return water is studied by the simulation platform.On the basis of the traditional differential pressure optimization method of the constant pressure, room load,outdoor temperature and vavle opening. The new optimization method is that joint control both the valve opening on the most unfavorable thermodynamic loop and the room load, which shows the superiority of the optimization method.Joint control both the room load and the most unfavorable thermodynamic loop valve opening show that more than 93% are in the most satisfactory range of valve opening and consume less energy consumption in the valve. Only 6.7% of the valve opening degree reached 100% that possibly appear the most unfavorable thermodynamic loop. The pump efficiency is greater than 0.5 is the lowest, although pump efficiency is the lowest. Comparing energy consumption of 6-8 months can be found n optimization method can save 76.8% energy consumption of the water pump.