Cooling liquid constant thermal apparatus and control method thereof

Abstract

The present invention is a cooling liquid constant temperature device and its control method. The electric regulating valve of the device includes a flow distribution valve and a controlled motor. The flow distribution valve has a hot liquid inlet, a cold liquid inlet, a first and a second outlet, and a hot liquid inlet. It is directly communicated with the valve chamber, the inlet of the cold liquid and the second outlet are communicated with the flow channel, and the flow channel and the first outlet are communicated with the valve chamber through the opening and closing member. The opening and closing part is connected with the rotating shaft controlled by the motor. The liquid storage tank, the pump, the heating element, the electric regulating valve and the refrigerator are connected to form a loop. The control unit is connected to the two temperature sensors in the liquid storage tank and the refrigerator and the motor of the electric regulating valve. The control method is that the control unit rotates the opening and closing part of the regulating valve according to the liquid temperature in the liquid storage tank, opens or closes the first outlet and closes or opens the flow channel in the same proportion, changes the ratio of hot and cold liquid entering the liquid storage tank, and adjusts the temperature. . The control unit controls the start and stop of the refrigerator according to the temperature of the liquid in the refrigerator, and determines that the stop is greater than the safety interval before starting. The invention is simple, low in cost and can accurately control the liquid temperature.

Description

(1) Technical field [0001] The invention relates to a device for automatically adjusting temperature and a control method thereof, in particular to a cooling liquid constant temperature device and a control method thereof. (2) Background technology [0002] In many industrial application fields, constant temperature control of cooling fluid is required. For example, laser marking machine needs constant temperature control of cooling water to ensure stable laser output power and good beam quality. Commonly used coolant constant temperature control methods include window control and frequency conversion continuous adjustment. [0003] Window control type: measure the temperature of the coolant, start the refrigerator when the coolant temperature is higher than the set upper limit, and shut down the refrigerator when it is lower than the set lower limit, and the coolant temperature is controlled to change between the set upper and lower limits. Since the refrigerator is not su...

AI Technical Summary

Problems solved by technology

This scheme has high temperature control accuracy, but the controller cost is high and uneconomical, which affects its popularization and application

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