Variable water temperature control system suitable for air conditioning secondary pump system

Abstract

The invention provides a variable water temperature control system suitable for an air conditioning secondary pump system, relates to the field of refrigeration control, and aims to improve the refrigerator power and hydraulic equilibrium adjusting accuracy of an air conditioning system and reduce energy consumption. The variable water temperature control system comprises a refrigerator device, a water supply / return pipeline, the air conditioning system and an equalizing pipeline. The air conditioning system comprises one or more air conditioning terminals, and the air conditioning terminals are of multiple types including fan coil pipes. A primary water pump and a secondary water pump are arranged on the water supply / return pipeline. The control system further comprises a refrigerator power preprocessing device, a refrigerator power control device and a secondary water pump variable-frequency control device, the refrigerator power preprocessing device is used for calculating the reflux ratio of the equalizing pipeline and the cold water temperature set value, and the refrigerator power control device is used for controlling the power of the refrigerator device. The secondary water pump variable-frequency control device is used for calculating the cold water equivalent valve position opening degree value of the fan coil pipes, and variable-frequency control is carried out over the secondary water pump according to the maximum valve position opening degree value in all air conditioning terminal cold water adjusting valves in the air conditioning system. The variable water temperature control system can be used for a frequency conversion technology in air conditioning.

Description

technical field [0001] The invention relates to the field of chiller control, in particular to a variable water temperature control system suitable for a secondary pump system of an air conditioner. Background technique [0002] At present, some chillers, especially large-scale central air-conditioning systems, use the frequency conversion technology of the first-level power frequency water pump and the second-level frequency conversion water pump. [0003] This is due to, as figure 1 As shown, the traditional primary water pump system is as follows: including chiller system (i.e. chiller device), primary water pump group, water supply pipeline and return water pipeline, wherein, the water supply pipeline includes water supply main pipe 5 and is arranged in parallel on the water supply main pipe Multiple water supply pipes 2 on 5, the return water pipeline includes a return water main pipe 6 and a plurality of return water pipes 3 arranged in parallel on the return water ma...

AI Technical Summary

Problems solved by technology

[0007] However, the air-conditioning load calculation value based on the above-mentioned chiller power control technology is usually calculated based on the water supply flow rate and the temperature difference between supply and return water. The reliability and accuracy of the flow meter is difficult to guarantee for long-term use, and it is also used for air-conditioning load calculation. The time difference between the supply water temperature and the return water temperature is obvious due to the different lengths and flow rates of the supply and return water pipelines, and the time difference is changing. The above factors often destroy the accuracy of the air conditioning load calculation, resulting in deviations in load adjustment and balance between supply and demand. It is difficult to really establish; and the above-mentioned hydraulic balance secondary pump frequency conversion control technology depends on the maximum valve opening at the end of the air conditioner, so it is only suitable for the application of the air conditioner end with a cold water valve whose stroke can be adjusted continuously, and cannot be applied to the two-way solenoid valve. Such as the air conditioner end of the fan coil type, so when facing the fan coil air conditioner end with a two-way solenoid valve, the hydraulic balance has the problem of poor adjustment accuracy or even difficult adjustment

[0008] To sum up, in the above-mentioned chiller power and hydraulic balance adjustment technology of the existing air-conditioning system, the above-mentioned technology has the problem of poor accuracy of chiller power and hydraulic balance adjustment

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