Control method for fast variable load of heat and power cogeneration units based on heat and power load conversion model

Abstract

The invention discloses a thermoelectricity cogeneration unit fast variable load control method based on a thermoelectric load conversion model, and belongs to the technical field of thermal power generating unit variable load control. The method is a control strategy combining heat supply and steam extraction adjustment with a traditional coordination control strategy, the load change in a varying duty early stage is mainly borne by the heat supply and steam extraction flow adjustment, the heat supply extraction flow begins to be reversely adjusted until an initial value is restored along with the gradual development of the adjusting action of a fuel amount; at a variable load control last stage, the control effect of the heat supply extraction flow adjustment on the load gradually disappears, and the load change is completely adjusted by the fuel amount; and through the combination with the heat supply and steam extraction heat storage adjustment and the machine furnace coordination,the response time of the system from the initial stage, the response speed of an intermediate transition stage and the adjustment precision of the final stabilization stage are both improved and optimized. According to the method, the operation safety of the unit can be ensured, the variable load characteristic of the unit can be improved, and the method plays an important role in access of a novel energy source and the improvement of the stability of a power grid.

Description

technical field [0001] The invention belongs to the technical field of variable load control of thermal power units, and in particular relates to a fast variable load control method for heat and power cogeneration units based on a thermoelectric load conversion model. Background technique [0002] In order to ensure the safe and stable operation of the power system, grid-connected generating units need to maintain the stability of grid frequency and the balance between supply and demand of grid energy at all times. Therefore, the generators need to continuously respond to the load command of the grid to meet the requirements of primary frequency regulation of the grid. In order to encourage units to quickly respond to grid dispatching requirements, my country's power grid companies have successively issued assessment rules to assess and reward and punish directly-regulated generator sets. Improving the variable load performance of units has become an important factor related ...

AI Technical Summary

Problems solved by technology

For cogeneration units that take into account both power generation and heat supply, the control strategy is more conservative when operating in the heat-constant power mode, and the load changing rate generally does not exceed 1% of the rated load, and some units even directly exit the coordinated control Change to manual control, it is difficult to meet the requirements of automatic generation control (Automatic Generation Control, AGC) of the grid

Images