VAV system start up air flow balancing method and system

Abstract

The invention discloses a VAV system start up air flow balancing method. The method comprises the following steps: mounting a manual adjusting air valve at the position of a branch air duct of an inlet of each VAV terminal device; carrying out a debugging step before use, operating an air conditioning unit at industrial frequency, opening all the adjusting air valves of the VAV terminal devices on the premise of not receiving related instructions of temperature adjustment control, adjusting the manual adjusting air valves, and enabling the supply air volume of each VAV terminal device to be close to but not less than a design value; and carrying out a normal operating control step, running the air conditioning unit at the industrial frequency at first, opening all the adjusting air valves of the VAV terminal devices on the premise of not receiving the related instructions of temperature adjustment control, supplying air for the VAV terminal devices according to the supply air volume which is required to be distributed and obtained from the debugging step, when temperatures, which are detected by temperature sensors, of rooms corresponding to the VAV terminal devices reach the set temperature, receiving the related instructions of temperature adjustment control by using the adjusting air valves of the VAV terminal devices, adjusting the open degree values of the adjusting air valves, and meanwhile, receiving a frequency converting control instruction by using the air conditioning unit. By the VAV system start up air flow balancing method, a number of problems which exist in an existing VAV system can be solved, and the VAV system is easy to maintain in the later period.

Description

Technical field [0001] The invention relates to a variable air volume air conditioning system with a VAV terminal device, and in particular to a method for balancing the air volume of the system at the start-up stage. Background technique [0002] At this stage, the variable air volume system (VAV system) does not have a manual adjustment damper at the inlet branch duct of the VAV-BOX. The commonly used control method during the start-up phase is: During the start-up phase of the VAV system, the VAV-BOX damper is controlled by the room temperature. In the fully open state, after running for a period of time, when the room temperature reaches the room temperature setting value, the air valve of the VAV-BOX is gradually closed. In this control mode, all VAV-BOX dampers are fully open during the start-up phase, which will inevitably produce the phenomenon of "favorable loop overcurrent, unfavorable loop undercurrent", and the VAV-BOX air supply in the favorable loop area Too much, ...

AI Technical Summary

Problems solved by technology

In this control mode, since all the air valves of the VAV-BOX are fully open during the start-up phase, the phenomenon of "overflow in the favorable loop and underflow in the unfavorable loop" will inevitably occur. The air supply volume of the VAV-BOX in the favorable loop area Too much, but the VAV-BOX in the unfavorable circuit area has little or no air supply, resulting in that the room temperature in the unfavorable circuit area cannot reach the design value after a long time; because the VAV-BOX inlet branch air duct is not set manually Adjust the air valve, the air volume through the VAV-BOX is all adjusted by the VAV-BOX air valve, the VAV-BOX in a favorable circuit will have a phenomenon of excessive noise due to excessive inlet pressure

The existence of these problems seriously reduces the comfort of the room and affects the mood and work efficiency of the staff

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