In an air cooled chiller, a refrigerant pump and bypass valve connected in parallel feed refrigerant from the condenser to a receiver; the pump is activated in response to condenser pressure; and the bypass is used otherwise. The condenser fan is controlled based on power consumption by the air cooled chiller that varies with ambient conditions. An evaporator set point is reset to meet load conditions. An expansion valve for the evaporator is controlled based on chilled water temperature, Delta T, or information from an air handling unit. Feedback of valve setting or position, temperature of air, valve size, and/or importance of an air handling unit is used to control the flow of chilled water. A variable pressure curve or other relationship is used with the feedback to control flow of chilled water based on the load. Refrigerant temperature is controlled based on information from the air handling unit.
展开▼
