Variable pressure difference control device, method and system for air-conditioner

The invention discloses a variable pressure difference control method for an air-conditioner. According to the opening degree Vmax of a chilled water valve of worst end equipment of an air-conditioner system, setup parameters of frequency converting control of a chilled water pump are dynamically adjusted, and namely, variable pressure difference energy-conservation control is achieved through the set value of the pressure difference delta Pset of a main water supply pipe and a main water return pipe. The invention further discloses a variable pressure difference control device and system for the air-conditioner. The device comprises an intelligent controller, an industrial computer, a frequency converter and the like and can achieve collection and feedback of parameters of a central air-conditioner. The intelligent controller is in data communication with a corresponding energy-conservation control device. By adopting the variable pressure difference control device, method and system for the air-conditioner, operation energy consumption of a chilled water system is reduced, an energy-conservation strategy meeting the user requirement is provided, and social benefits and economic benefits are remarkable for improving the utilization efficiency of the energy.