Introduction  In order to adapt to the demand of the original thermal power units for new energy power consumption, improving its peak regulating capacity is one of the key factors. The heat storage system is an important way of "thermoelectric decoupling" of coal-fired thermal power units, so it has engineering reference value to evaluate its parameter matching.

  Method  A method of coupling heat storage device was used to increase the depth peak regulation capacity of coal-fired unit. Combined with the power curve of heat load and electric load, the influence law of heat storage device parameters was systematically studied.

  Result  The results show that with the regional load curve as a typical case, when the heat storage capacity and charging and releasing rate parameters of the heat storage tank increase, the heat load regulation capacity of the unit reaches 112.75 MW and 129 37 MW·min respectively, and the depth peak regulation parameter is about 110 MW. Besides, the heat storage capacity and the heat charging and discharge rate match, and the bottleneck factors will directly restrict the depth peak regulation performance of the system.

  Conclusion  By integrating the boundary situation of heat storage and heat discharge, the role of the heat storage tank in the auxiliary peak regulation process is accurately demonstrated. Combined with the optimization design of its operation strategy, the parameter matching relationship of the heat storage auxiliary peak regulation system can be further analyzed to provide a reference for the parameter design of the coupled thermal storage system of thermal power units.