Cooling water flow control method for optimizing total energy consumption of refrigerating machine and cooling water pump

Abstract

The invention belongs to the technical field of energy conservation of a central air-conditioning system, and particularly relates to a control method for optimizing cooling water flow of total energy consumption of a refrigeration apparatus and a cooling water pump. The method comprises the following steps: signal acquisition, signal treatment and conversion, primary control operation, secondary control operation, controlled quantity output and control of task execution. in the method, partial derivative of total power of the refrigeration apparatus and the cooling water pump to condensing pressure is taken as a parameter that represents whether the total power is in an approximately optimal sate or not, and the partial derivative of the total power of the refrigeration apparatus and the cooling water pump to the condensing pressure is calculate online by acquiring the parameter of the condensing pressure and parameters of temperature and flow rate of cooling water, and the flow rate of the cooling water is controlled according to the value of the partial derivative, thereby realizing that the total power of the refrigeration apparatus and the cooling water pump approaches minimum, at the time, the value of the partial derivative is close to zero, so that energy conservation effect of variable flow of the cooling water can be played to the utmost extent.

Description

technical field [0001] The invention belongs to the technical field of energy saving of a central air-conditioning system, and in particular relates to a cooling water flow control method for optimizing the total energy consumption of a refrigerator and a cooling water pump. Background technique [0002] During the operation of the central air-conditioning system, the air-conditioning load changes with the indoor and outdoor parameters and the frequency of use. The time to reach the design load in a year accounts for a small proportion of the total operating time. Multiplied by the safety factor, the capacity of the refrigerator is often too large. Therefore, the chiller runs at part load most of the time. Therefore, how to effectively control the system under partial load becomes the key to energy saving of air conditioners. The variable flow cooling water pump can change the cooling water flow according to the change of the air conditioning load, thereby reducing the ene...

AI Technical Summary

Problems solved by technology

The comprehensive energy-saving effect of the refrigerator and the cooling water pump is not ideal, and the energy-saving benefit of variable flow of cooling water is not reflected to the greatest extent.

In addition, due to the thermal inertia of the cooling water in the system, if the temperature difference or temperature is used as the controlled parameter, there will be serious hysteresis, and the adjustment quality is not high

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