Temperature control device for refrigerated or frozen storage cabinets

Abstract

This device includes: a compressor, multiple freezers, and a main controller. Each of the multiple freezers includes: an electronic expansion valve, an evaporator, and a controller. The controller is electrically connected to the electronic expansion valve, a low-pressure side barometer of the gaseous refrigerant, an evaporator temperature sensor, a freezer temperature sensor, and a freezer temperature setting interface, and is also electrically connected to the compressor, a high-pressure side barometer of the gaseous refrigerant, and the multiple controllers. The multiple freezers are arranged in parallel. The main controller executes a multi-machine collaborative control path to select a current freezer and executes a steady-state determination module. When it is confirmed that the current freezer has not reached thermal equilibrium, a nonlinear adaptive control path is executed; otherwise, a steady-state energy-saving control path is executed, causing the current freezer to enter a cruise operation control state.

Claims

1. A freezer temperature control device, comprising: a shared unit including a compressor; a heat dissipation condenser connected to an outlet of the compressor; and a high-pressure side pressure gauge for gaseous refrigerant connected to the outlet of the compressor; a plurality of freezers, each of the plurality of freezers comprising: an electronic expansion valve connected to an outlet of the heat dissipation condenser; an evaporator connected to an outlet of the electronic expansion valve; a freezer temperature sensor for sensing the freezer temperature of any one of the plurality of freezers; a freezer temperature setting interface; and a controller electrically connected to the electronic expansion valve, the freezer temperature sensor, and the freezer temperature setting interface; and a main controller electrically connected to the compressor, the high-pressure side pressure gauge for gaseous refrigerant, and the controller of any one of the plurality of freezers; wherein the plurality of freezers are arranged in parallel, such that each of the plurality of freezers forms a refrigerant circuit via a refrigerant pipeline, the compressor, and the heat dissipation condenser; The main controller executes a multi-machine collaborative control path to select a current freezer, which is the freezer to be prioritized among the multiple freezers; the main controller executes a steady-state determination module to confirm whether the current freezer has reached thermal equilibrium. When the current freezer has not reached thermal equilibrium, the main controller executes a nonlinear adaptive control path; when the current freezer has reached thermal equilibrium, the main controller executes a steady-state energy-saving control path to enable the current freezer to enter a cruise operation control state.

2. The freezer temperature control device as claimed in claim 1, wherein any one of the plurality of freezers further comprises: a gaseous refrigerant low-pressure side barometer connected to an outlet of the evaporator; and an evaporator temperature sensing rod for sensing the temperature at the outlet of the evaporator; the controller is further electrically connected to the gaseous refrigerant low-pressure side barometer and the evaporator temperature sensing rod, respectively.

3. The freezer temperature control device as described in claim 1 or 2, wherein when the current freezer enters the cruise operation control state, the main controller sets the current freezer as a steady-state freezer, and then executes an actuator drive module to adjust the opening degree of the electronic expansion valve and the speed of the compressor of the current freezer, and then the main controller executes the multi-machine cooperative control path.

4. The temperature control device for the freezer cabinet as described in claim 3, wherein, The multi-machine collaborative control path sets the "queueing order" of the freezers corresponding to the steady-state freezer to the lowest priority, so that the steady-state determination module will prioritize processing the freezers that have not been set as steady-state freezers among the plurality of freezers.

5. The freezer temperature control device as described in claim 1 or 2, wherein the multi-machine collaborative control path includes a collaborative control manager and a plurality of independent decision programs, the plurality of independent decision programs corresponding one-to-one with the plurality of freezers, the collaborative control manager can launch the plurality of independent decision programs in a decentralized manner, such that the plurality of independent decision programs first evaluate the real-time thermal saturation point and real-time refrigerant flow requirement of their respective freezers, and then, based on the state of their respective freezers, collaboratively determine the "queueing order" of the plurality of freezers, and select the freezer with the highest priority in the "queueing order" as the current freezer.

6. The temperature control device for a freezer cabinet as described in claim 1 or 2, wherein the nonlinear adaptive control path comprises: a nonlinear interval determination module, a modulation feature selector, a pulse controller (PWM) connected in series, and a "thermal feedback feature acquisition and parameter adaptive path".

7. The freezer temperature control device as described in claim 6, wherein the nonlinear interval determination module configures the difference between the current real-time "freezer temperature value" and the "set freezer temperature" and the change trend of the current real-time "evaporator pressure value" of the freezer into one of a preset plurality of discrete logic sensing intervals; the modulation feature selector dynamically loads a pulse width and frequency combination most suitable for the current freezer state according to the configured logic sensing interval; the pulse controller generates a corresponding precise control signal according to the pulse width and frequency combination, and transmits the corresponding precise control signal to an actuator drive module, so as to drive the controller of the current freezer through the actuator drive module to directly adjust the opening of the electronic expansion valve and the speed of the compressor of the current freezer.

8. The freezer temperature control device as described in claim 6, wherein the main controller executes the "thermal feedback feature acquisition and parameter adaptive path", which includes: a thermal feedback feature acquisition step, a refrigerant discrimination module, and a parameter adaptive adjuster to simultaneously optimize and update the opening degree of the electronic expansion valve and the speed of the compressor for the current freezer.

9. The temperature control device for a freezer cabinet as described in claim 8, wherein, The thermal feedback feature acquisition step monitors in real time the "superheat" and "pressure feedback rate" of the electronic expansion valve of the current freezer after valve operation; the refrigerant identification module automatically identifies the type of refrigerant in the refrigerant pipeline; the parameter adaptive adjuster updates the opening degree of the electronic expansion valve and the speed of the compressor of the current freezer in real time.

10. The freezer temperature control device as claimed in claim 6, wherein the main controller receives and, based on an evaporator temperature value, a freezer temperature value, an evaporator pressure value, and a set freezer temperature transmitted from the controllers of the plurality of freezers, calculates the difference between the "freezer temperature value" and the "set freezer temperature" of each of the plurality of freezers, their respective real-time refrigerant flow characteristics, and their respective superheat, and calculates and generates an expansion valve control command for each of the electronic expansion valves and a compressor control command for each of the compressors.

11. The freezer temperature control device as claimed in claim 10, wherein the main controller transmits expansion valve control commands for each of the plurality of freezers to their respective controllers and converts them into expansion valve control signals to control the opening degree of the electronic expansion valves of each of the plurality of freezers, and the main controller transmits compressor control commands to the compressor to control the speed of the compressor.

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