Control method of cooling tower water outlet temperature of central air-conditioning system

Abstract

The invention discloses a control method of cooling tower water outlet temperature of a central air-conditioning system. The central air-conditioning system comprises a control device, a cooling tower set, a cooling pump set and a cold water unit; the inlet side of the cooling pump set is connected with the water tank side of the cooling tower set, the outlet side of the cooling pump set is connected with a water inlet in the cooling side inlet of the cold water unit, a water outlet of the cooling side of the cold water unit is connected with the spraying side of the cooling pump set, and the control device is connected with the cooling tower set and the cooling pump set. The control method includes the steps that the control device achieves the aim that the cooling tower water outlet temperature reaches or is close to the outdoor wet ball temperature by controlling the number of cooling towers putting into operation and / or controlling the number and / or frequency of draught fans of the cooling towers putting into operation. By means of the control method, the cooling tower water outlet temperature can reach or be close to the outdoor wet ball temperature, and the central air-conditioning system has the character of finding the wet ball temperature by itself.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a method for controlling the outlet water temperature of a cooling tower of a central air conditioning system. Background technique [0002] In the central air-conditioning system, the return water temperature on the cooling side of the chiller (that is, the outlet water temperature of the cooling tower) has a great influence on the energy consumption of the unit. For example, when the return water temperature on the cooling side increases by 1 °C, the COP of the unit may decrease by 3. %. Regardless of the performance of the cooling tower itself, the outlet water temperature of the cooling tower is affected by the outdoor wet bulb temperature, that is to say, the higher the outdoor wet bulb temperature, the higher the lower limit temperature of the outlet water of the cooling tower. [0003] However, the outdoor wet bulb temperature changes with time and climate. Alth...

AI Technical Summary

Problems solved by technology

Although the outdoor wet bulb temperature can be measured by a wet bulb temperature sensor or a temperature and humidity sensor, it is often impossible to accurately measure the wet bulb temperature around the cooling tower due to the limited installation position of the sensor, resulting in large measurement errors

In addition, the measurement accuracy of the wet bulb temperature sensor or the temperature and humidity sensor will also drift over time

Therefore, it is often inaccurate to control the outlet water temperature of the cooling tower based on the wet bulb temperature measured by the outdoor wet bulb temperature sensor or the temperature and humidity sensor

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