Control method, device and system for chiller

Abstract

The application provides a control method, device and system for a chiller. The control method is applied to a controller of an air-conditioning system. The air-conditioning system includes a cooling tower, a plate heat exchanger, a chiller and a controller. The chiller includes a condenser and an evaporator. . The lower tower header of the cooling tower is connected to the plate heat exchanger, the upper tower header of the cooling tower is connected to the chiller, the plate heat exchanger is connected to the chiller, and the controller is respectively connected to the temperature sensor at the inlet of the condenser and the temperature sensor at the inlet of the evaporator. Temperature sensor, cooling tower, plate heat exchanger connection. The controller obtains the inlet temperature values ​​of the evaporator and the condenser in real time, as well as the flow rate of the chiller side, and adjusts the inlet temperature of the chiller side by adjusting the valve on the cooling side of the plate heat exchanger, and by adjusting the cooling fan speed of the cooling tower, Adjust the inlet temperature of the cooling side of the chiller. The above method makes the load rate of the chiller not lower than the minimum load rate to ensure that the chiller does not surge.

Description

technical field [0001] The present application relates to the technical field of air conditioners, and in particular, to a control method, device and system for a chiller. Background technique [0002] In the occasions where cooling is required all the year round, for the air-conditioning system composed of chillers, plate heat exchangers, cooling towers, water pumps, etc., when the outdoor temperature drops, the chilled water can be partially cooled by the plate heat exchanger and cooling tower in advance. Then let the chilled water enter the chiller, and the chiller will lower the temperature of the chilled water to the set temperature. This operating mode is generally referred to as the semi-free cooling mode. [0003] In the semi-free cooling mode, in order to make the plate heat exchanger contribute more load, it is necessary to reduce the water temperature of the lower tower of the cooling tower, but the too low water temperature of the lower tower will not only reduc...

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Problems solved by technology

[0003] In the semi-free cooling mode, in order to make the plate heat exchanger contribute more load, it is necessary to reduce the water temperature of the lower tower of the cooling tower, but too low water temperature of the lower tower will not only reduce the load rate of the chiller to the minimum load rate, but also It will reduce the temperature of the water flowing into the condenser of the chiller to its limit value, which will cause the condensing pressure to be too low and prevent the chiller from working properly

[0004] At present, for the control of semi-free cooling conditions, manual debugging is used to ensure the minimum load rate of the chiller. There is no clear quantitative index for control, and the normal operation of the chiller cannot be fully guaranteed.

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