Abstract: The present application discloses a control method for an HVAC system in a relatively large spatial place and the HVAC system. The HVAC system comprises an air handling unit, and the air handling unit is provided with a valve through which a fluid medium passes and a fan; and the method comprises: monitoring a return air temperature of air circulated back to the air handling unit; providing a return air temperature setpoint of the HVAC system; and performing decoupling adjustment on one of the fan and the valve, and then adjusting the other of the fan and the valve so that the return air temperature is close to the return air temperature setpoint. According to the present application, the HVAC system can operate in a steady and energy-saving way.

Abstract: The present application discloses a control method for an HVAC system in a relatively large spatial place and the HVAC system. The HVAC system comprises an air handling unit, and the air handling unit is provided with a valve through which a fluid medium passes and a fan; and the method comprises: monitoring a return air temperature of air circulated back to the air handling unit; providing a return air temperature setpoint of the HVAC system; and performing decoupling adjustment on one of the fan and the valve, and then adjusting the other of the fan and the valve so that the return air temperature is close to the return air temperature setpoint. According to the present application, the HVAC system can operate in a steady and energy-saving way.

Abstract: A refrigeration system, a fault diagnosis system and a fault diagnosis method for the refrigeration system, a controller and a storage medium. The fault diagnosis method includes: receiving a fault alarm sent by an associated refrigeration system, and acquiring a fault cause list associated with the fault alarm; determining whether to run a fault diagnosis system associated with the fault alarm; and when the fault diagnosis system associated with the fault alarm is run, checking the associated refrigeration system sequentially according to the fault cause list, and acquiring a fault cause and a repair means list associated with the fault cause.

Abstract: A refrigeration system, a fault diagnosis system and a fault diagnosis method for the refrigeration system, a controller and a storage medium. The fault diagnosis method includes: receiving a fault alarm sent by an associated refrigeration system, and acquiring a fault cause list associated with the fault alarm; determining whether to run a fault diagnosis system associated with the fault alarm; and when the fault diagnosis system associated with the fault alarm is run, checking the associated refrigeration system sequentially according to the fault cause list, and acquiring a fault cause and a repair means list associated with the fault cause.