Variable air volume air conditioning system total air volume control method based on operation curve

Abstract

The invention provides a variable air volume air conditioning system total air volume control method based on an operation curve. The control method comprises the following steps that S1, a resistancecharacteristic curve a of a pipeline system is obtained, the mathematical expression of the resistance characteristic curve a is P=Sa.Q<2>, wherein P represents the pipeline resistance, the unit of the pipeline resistance is Pa, Sa represents a pipeline resistance coefficient, Q represents the air volume, and the unit of the air volume is m<3> / h; S2, characteristic curves of a fan at various rotating speeds are obtained, the characteristic curves comprise a P-Q curve and an Ng'-Q curve, wherein P represents the fan pressure head, the unit of the fan pressure head is Pa, Q represents the air volume, the unit of the air volume is m<3> / h, Ng' represents input powers of the fan at various rotating speeds, and the unit of the input powers is kW; S3, the operation curve c of the fan is solved;S4, an Ng'-f curve is determined, wherein f represents the operation frequency of the fan, and the unit of the operation frequency is Hz; and S5, the total air volume adjustment control is carried outaccording to the operation curve c of the fan. The method is simpler than static pressure control in control form, belongs to partial feed-forward control, and is relatively rapid and stable in adjustment.

Description

technical field [0001] The invention relates to a variable air volume control method for a central air conditioner, in particular to a total air volume control strategy for a variable air volume (VAV) air conditioning system. Background technique [0002] The central air-conditioning variable air volume system refers to an air-conditioning system in which the air-conditioning system automatically adjusts the air supply volume according to regional load changes and requirements. The variable air volume system can overcome that the constant air volume air-conditioning system only uses one air supply parameter, which cannot meet the requirements of different rooms or different areas. The problem of different indoor air environment requirements can also avoid the intolerable problems of indoor ceiling condensate and mold pollution that are often accompanied by fan coil systems. For large air-conditioning systems, it can effectively save operating costs. [0003] There are three...

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Problems solved by technology

However, the air volume control method in the prior art inevitably uses a pressure detection device, or the valve position signal and air volume value of the terminal device, thus facing the problems of pressure fluctuation and turbulent flow in the air duct that are often encountered in static pressure measurement, and adjusting The hysteresis problem is relatively complicated in the control form, and has some approximate assumptions, and belongs to feedback control and pressure control, the adjustment speed is slow and not smooth enough, and the control accuracy is not high

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