Optimization Control Software Development For Heating Ventilating And Air-Conditioning System

At present, the building energy consumption, along with industrial energy consumption and transport energy consumption, has become the energy consumption of the top three "energy-hungry". The building energy consumption accounts for about 30% of total energy consumption, of which HVAC energy consumption accounts for about 60%. In general, the design of HVAC system is based on the assumption that the system works on the rated loads which satisfies the rated load of the customers. The operation mode of fixed-point of work which is designed by the rated load is the key problem of causing the low EER (Ratio of Energy and Efficiency) of HVAC. It was a major problem about how to optimize HVAC system.Chiller is a complex heat exchange system, which is composed by the chilled water loop and cooling water loop through the Carnot cycle of compressor and Refrigerant circuit. The energy consumption of the chiller is the largest energy consumption equipment of HVAC, which is about 50 percent of the whole system. The key problem of reducing energy consumption is how to make the refrigeration capacity and the load of real-time changes match the best.In this paper, according to the operating process, the chiller's characteristics of energy consumption of various devices, the characteristics of different application object, chilled water supply temperature, cooling water supply temperature and cooling load, the energy consumption model of chiller are set up with the Least Square Method and the Grid modeling method. According to the different characteristics of energy consumption model and the application, chilled water temperature and load constraints for the HVAC, the optimization problem of HVAC refrigeration system with characteristics of non-linear, multivariable and strong coupling is completed by the grid search optimization method, polynomial method and the improved particle swarm optimization, which solves the optimization problem of work point. The software of optimize and control the work point of HVAC refrigeration on-line is developed on the basis of Visual C++ and SQL technology.Through verifying by the actual data, the experimental results show that the above two models can reveal the characteristics of energy consumption of chiller clearly; at the same time, all of the above three methods can achieve the objective that the work point optimization of condenser supply water temperature, condenser water supply flow, and cooling tower air flow on-line on HVAC refrigeration system at different loads, operating conditions and initial conditions. It achieves the goal of the refrigeration capacity and the load of real-time changes match the best, and the goal of reducing the energy consumption of HVAC refrigeration system.