Study On Energy Saving Control Of Air Conditioning Chilled Water System In Subway Station

Subway as a convenient underground traffic mode, can ease the pressure on the ground traffic, has significant social and economic benefits. Ventilation and air conditioning system as the main energy consumption of the subway station, its power consumption accounts for about 25%-35% of the total electricity consumption of subway station. Chilled water system is an important part of air conditioning system in subway station. The operation state and the energy consumption of the system directly affect the running efficiency of the whole system.Due to the limitation of the original design, equipment selection and other problems, the 65% of the chilled water system is running under the maximum load of 90%, resulting in a large amount of energy wasted. Therefore, it is of great practical significance to study the energy saving optimization of air conditioning chilled water system in subway station.This topic takes the subway station air conditioning chilled water system as the research object, the different operation modes of the chilled water pump and the energy saving control strategy are studied in depth. The main research work includes:(1) Research the frequency conversion operation mode of chilled water primary pump, and put forward a control strategy of variable chilled water inlet temperature.Aiming at the problem of energy waste in the fixed frequency operation mode of air conditioning chilled water pump, research the feasibility of the variable frequency and variable flow operation mode of chilled water primary pump, and analyse the advantages and disadvantages of different frequency control strategies Based on the traditional temperature control strategy, propose a energy saving control strategy of variable chilled water inlet temperature, and give the concrete control flow and the realization method.(2) To build the subway station ventilation and air conditioning system simulation platform and simulation experiment researchUsing TRNSYS to build a subway station building model and analysis to verify the accuracy and reliability of the model, then built subway station ventilation and air conditioning system simulation platform, the chilled water pump fixed frequency and frequency two operation modes of simulation experiment results were compared to verify variable chilled water inlet temperature control strategy for the energy saving effect.(3) Verify the feasibility of the control strategy of variable chilled water inlet temperature and the effect of energy saving in the actual subway training platformIn Beijing, a college subway training platform for the transformation of chilled water system, compile the PLC control procedures, and development the data acquisition and monitoring system. Verify the feasibility and energy saving effect of variable chilled water inlet temperature control strategy by comparing the energy consumption of the water pump fixed frequency operation mode. The experimental results show that: compared with the current fixed frequency operation mode, the energy saving rate of the chilled water inlet temperature control strategy is up to 12.4%.