| Energy and environment have become the two major themes today, the development of energy-saving technology and use of clean energy has gained more and more attention. With the improving of people’s living standards, our requirement for indoor air quality is more and more strict, the use of air conditioning got popularity. Data show that energy consumption of air-conditioning in China accounted for 55% of the total building energy consumption, and the pressure on the environment is also growing. As gas heat pump energy has relatively high utilization rate, good partial load characteristic, less pollution to the environment, especially it has better effect in the case of heating, and it can be used to adjust balance of power peak. It has been widely used in Europe and the United States, in our country it is gradually paid more attention to.Compared with the ordinary gas heat pump system, the hybrid-power gas heat pump can make the engine work in the economic area, the main research of this paper is a continuous transmission ratio of the hybrid gas heat pump system, by changing the transmission ratio of gas heat pump, the speed of the gas pump is not affected by the restrictions of the compressor, the gas engine could work in a more efficient state, the main contents of this paper include the following aspects:(1)The gas heat pump system which has variable transmission is designed.This paper presents a hybrid gas heat pump system which has continuous transmission, the system mainly includes three parts:driving system, transmission system and heat pump. The system will release the speed of gas engine and the motor from the compressor, he hybrid heat pump system has four operation modes:gas engine driven mode, motor driven mode, gas engine driven and charging mode, the gas engine and motor drive mode, we take a detailed analysis of the energy flow process of four modes.(2) Establish the mathematical model of hybrid gas heat pump systemThe model of gas heat pump hybrid system mainly includes three parts:the drive system model, transmission model and heat pump system model. The drive system model includes the model of gas engine, motor and battery. In this paper experimental modeling and universal curve model of gas engine is established, the charge discharge efficiency model of the battery is established in this paper using experimental modeling method.The model of heat pump system mainly comprises a compressor, a condenser, an evaporator, a throttle valve and other parts of the heat pump. The transmission is a bridge to link the heat pump system and drive system, this paper builds a mathematical model of the transmission according to the relationship between input and output transmission.(3) The logic threshold control strategyThe logic threshold control strategy is to establish reasonable logic rules to change and adjust working condition of the drive system, make the engine run in the vicinity of the optimal fuel consumption curve, as to achieve high efficiency and low emission. The power demand of the drive system of the compressor is set as the threshold value, according to the SOC of accumulator, we choose reasonable working point of the motor and gas engine. According to the external load of the system, we set up the simulation platform based on Matlab/Simulink, and take the simulation in a cycle.(4) The instantaneous optimization control strategyInstantaneous optimization refers to in a current external load demand, how to get reasonable allocation of power between gas engine and electric motor in order to reach the best operation state instantaneous system, the instantaneous optimization control strategy requires a optimization parameter, in this paper we choose the equivalent instantaneous gas consumption as optimization parameter, compared with the logic threshold control strategy in the same conditions, results show that the instantaneous optimization control strategy with respect to the logic threshold control strategy has a good energy-saving effect. |
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