System and method for controlling an economizer circuit
AssigneesJohnson Controls Technology Company, York International Corporation
InventorsCurtis Christian CRANE, Frank Highland HILL, Glenn Eugene NICKEY
Life of this patent
Estimating the term…
Abstract
A control algorithm for controlling an economizer circuit in a chiller system is provided. The control algorithm opens and closes a port valve in the economizer circuit in response to predetermined criteria to engage and disengage the economizer circuit. The predetermined criteria can include an operating parameter of a compressor and a level of liquid refrigerant in a flash tank.
Claims20
A method for controlling an economizer circuit in a chiller system, the method comprising the steps of:
- providing an economizer circuit for a chiller system having a flash tank, an inlet line to the flash tank and an outlet line from the flash tank connected to an economizer port of a compressor of the chiller system, the outlet line including a valve to control flow of refrigerant in the outlet line;
- determining whether a level of liquid in the flash tank is less than a predetermined level;
- determining whether an operating parameter of the compressor is greater than a first predetermined value related to the operating parameter of the compressor;
- and
- actuating the valve to engage the economizer circuit in response to a determination that the liquid level in the flash tank is less than the predetermined level and a determination that the operating parameter of the compressor is greater than the first predetermined value related to the operating parameter of the compressor.
A method for controlling an economizer circuit in a chiller system, the method comprising the steps of:
- providing an economizer circuit for a chiller system having a flash tank, an inlet line to the flash tank and an outlet line from the flash tank connected to an economizer port of a compressor of the chiller system, the outlet line including a valve to control flow of refrigerant in the outlet line;
- determining whether an outdoor ambient temperature is less than a predetermined temperature;
- determining whether an operating time for the compressor is less than a predetermined time period;
- determining whether a level of liquid in the flash tank is less than a predetermined level;
- and
- actuating the valve to engage the economizer circuit in response to a determination that the liquid level in the flash tank is less than the predetermined level and a determination that the outdoor ambient temperature is less than a predetermined temperature and a determination that the operating time for the compressor is less than a predetermined time period.
A chiller system comprising:
- a refrigerant circuit comprising a compressor, a condenser arrangement, an expansion valve and an evaporator arrangement connected in a closed refrigerant loop;
- an economizer circuit connected to the refrigerant circuit, the economizer circuit comprising a flash tank having a first outlet line in fluid communication with the expansion valve and a second outlet line in fluid communication with the compressor, the second outlet line comprising a valve to control flow of refrigerant from the flash tank to the compressor;
- and
- a control panel to control the valve to activate and deactivate the economizer circuit, the control panel being configured to open the valve to activate the economizer circuit in response to a liquid level in the flash tank being less than a predetermined level and an operating parameter of the compressor being greater than a first predetermined value related to the operating parameter of the compressor.
Dependencies are inferred from the claim text.