Improved MFAC (Model Free Adaptive Control) based data driving energy conservation control system and method of refrigerating system

Abstract

The invention discloses an improved MFAC (Model Free Adaptive Control) based data driving energy conservation control system and method of a refrigerating system. The system comprises a constant freezing water supplying temperature control loop and a variational minimization superheat degree control loop, wherein the constant freezing water supplying temperature control loop consists of a PID controller and a transducer; the variational minimization superheat degree control loop comprises a model free adaptive algorithm controller, an electronic expansion valve and an evaporator. The method is characterized in that the frequency of a compressor is adjusted through the PID controller according to the variation of the system load in order to enable constant freezing water supplying temperature, and as a result, the refrigerating capacity fits the heat load; a relation curve between the system load and the minimum stabile superheat degree of the evaporator is acquired through experiment, thus the load of the system can be calculated in real time, and the minimum stable superheat degree corresponding to the load can be calculated through a linear difference method according to the relation curve; the minimum stable superheat degree corresponding to the refrigerating load is treated as the superheat degree setting value in the variational minimization superheat degree control loop; and the superheat degree of the evaporator is controlled by an MFAC control algorithm with retardation time limitation through the electronic expansion valve.

Description

technical field [0001] The invention relates to an energy-saving control method of an MFAC refrigeration system with a lag time constraint, and belongs to the field of optimal control of an air-conditioning system. Background technique [0002] With the continuous acceleration of my country's urbanization process, a large number of office buildings, hotels, shopping malls and other buildings have been built, and these buildings are equipped with central air-conditioning systems. With the improvement of people's living standards, air-conditioning facilities have been used in urban residential buildings and even houses in villages and towns. At present, my country's building energy consumption accounts for about 30% of the total energy consumption, of which air-conditioning energy consumption accounts for 50% to 70%, and air-conditioning energy consumption even accounts for 1 / 3 of the total urban electricity load during the peak electricity consumption period in summer. Most ...

AI Technical Summary

Problems solved by technology

This method adds the input change rate constraint item with lag time into the control rate calculation process, which can better solve the large time lag problem and greatly improve the response speed of the refrigeration system; and this method is based on the controlled system The input and output data of the controlled system does not need to establish a mathematical model of the controlled system, the amount of calculation is small, it is easy to implement, and it can avoid problems such as poor control effects that may be caused by inaccurate system models

Images