Analysis On Peak Regulation Capability Of Cogeneration Units With Absorption Heat Pump

The use of absorption heat pump recycle unit exhaust heat for district-heating system with the economic benefits and environmental benefits, which is identified as the main energy-saving technology in Cogeneration industry. These measures can effectively improve the efficiency of the thermoelectric cycle and enhance heat-supply capacity. The development of economy has changed the structure of electricity and electricity demand in China, and the power system has the characteristics of increasing the peak and valley difference and increasing the demand of peak shaving. Combined heat and power generating units are involved in peak shaving, which is an important way to solve the problem of peak and valley difference and wind power consumption.The thermal power units with absorption heat pumps is the main research object.The purpose of paper is to obtain the supply capacity of the CHP. The paper explore the influence of heat-supply and influence factors of peak regulation, and also establish principles of peak regulation range calculation. The specific contents are as follows:(1) The paper analyzes the circulation process of the heat pump, and establishes two models based on efficiency factor method and the actual cycle.Meanwhile, two models are compared and verified by the operation data. The application and selection baseis of the two models are determined.(2) The paper establishes a simulation model of thermal power units based on VOW mode parameters, and also sets up a correction method to improving the accuracy, based on the revise of compression control, the stage efficiency and steam loss of low pressure cylinder. Then two models simulation results are compared with the design parameters to verify the accuracy.(3) In order to evaluate the influence of external parameters on the heat supply,the model was used to analyze the changes of the external factors (circulating water,parameter of extraction steam and so on). In this paper, Extraction pressure and heating network temperature) on the heating coefficient COP of the absorption heat pump, which provides a reference for the stable heating load control during the actual peak load regulation.(4) The calculation principle of maximum load and minimum of CHP is established in this paper based on limiting factor of peak in CHP. With the of simulation model ,the thermoelectric shaving load is draw ,and we get relation formula of peak regulation limits, which can be used for the thermo - electric load dispatching and the guidance of the power plant. Taking into account the fact that the heat pumps are easily to be affected by many factors during peak shedding period, the paper analyzes the peak capacity influenced by COP. The heat pumps increase the performance of the unit peak load to 91% compared with traditional heart supply for design heat supply. The operation of the heat pump in the case of heating can significantly enhance the peak load shedding capacity, with the reduction of the heat pump COP.