Control method and device of refrigeration system

Abstract

The invention provides a control method and device of a refrigeration system. The control method comprises the following steps that a first temperature difference delta T1 between an inlet end temperature and an outlet end temperature of an evaporator is compared with a first target temperature difference value T10; if delta T1 is larger than T10 plus n, a PID controller is adjusted to reduce theoutput amount; if delta T1 is smaller than T10 minus n, the PID controller is adjusted to increase the output amount; the output amount is continuously adjusted to obtain N groups of first temperaturedifference delta T1 until delta T1 is larger than T10 minus n and smaller than T10 plus n, and the output amount is kept unchanged; a second temperature difference delta T2 between the evaporation temperature of the refrigerant and a set value is compared with a second target temperature difference value T20; if delta T2 is larger than T20 plus m, the PID controller is adjusted to reduce the output amount; if delta T2 is smaller than T20 minus m, the PID controller is adjusted to increase the output amount; the output amount is continuously adjusted to obtain M groups of second temperature difference delta T2 until delta T2 is larger than T20 minus m and smaller than T20 plus m, and the output amount is kept unchanged; the small output amount in the two steps is selected as the final output amount; and based on the final output amount, the opening degree of a throttling element is controlled. According to the control method, the temperature intelligence and continuity adjustment of the refrigeration system can be realized.

Description

technical field [0001] The invention relates to the technical field of refrigeration system control, in particular to a method and device for controlling a refrigeration system. Background technique [0002] The statements in this section only provide background information related to the present disclosure and may not constitute prior art. [0003] At present, the traditional PID algorithm based on temperature deviation has serious drawbacks in the application of mechanical refrigeration. Specifically, the traditional PID algorithm judges the output according to the difference between the temperature set point (SP) and the temperature actual value (PV). For example, in a schematic scenario, if it is desired to reduce the cooling temperature from the current 150°C to -70°C (the temperature drop reaches 220°C), the PID algorithm determines that the output is 100%. At this time, the capillary is opened with the maximum flux, and the Freon flow increases sharply in order to r...

AI Technical Summary

Problems solved by technology

[0005] However, the above solutions need to be adjusted manually, and the intelligence needs to be further improved

Moreover, increasing or decreasing the number of refrigeration pipelines can easily lead to a jump in the refrigeration temperature, and it is difficult to achieve continuous temperature adjustment.

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