Expansion valve control
AssigneeCarrier Corporation
InventorsArthur F. Friday, Richard E. Ginn, Edward F. Wright, Jr.
Life of this patent
Estimating the term…
Abstract
A control for the expansion valve of an air conditioning system interrupts a decision to deactivate one or more stages of compression and proceeds to calculate a new expansion valve position based upon the amount of capacity to be lost by the deactivated stages of compression. The expansion valve is commanded to the calculated position before the compressors are deactivated.
Claims6
In an air conditioning system having a plurality of stages of compression for processing refrigerant flowing through an expansion valve, a process for controlling the valve position of the expansion valve when one or more stages of compression are to be deactivated, said process comprising the steps of:
- sensing when one or more stages are to be deactivated;
- interrupting the deactivation of the stages;
- calculating a new valve position for the expansion valve based on the number of stages to be deactivated;
- and
- commanding the expansion valve to move to the new valve position before releasing said step of interrupting the deactivation of the stages.
The process of claim 6 wherein each stage has a defined cooling capacity so that current air conditioning system capacity is equal to the total of all the defined heating or cooling capacities of the currently active stages and wherein said step of calculating new position for the expansion valve comprises the steps of:
- determining the fractional amount of current air conditioning system capacity to be affected by deactivating the stages;
- reading the current valve position of the expansion valve;
- adjusting the read valve position of the expansion valve by an amount equal to a minimum valve open position;
- and
- multiplying the determined fractional amount of affected capacity times the adjusted, read valve position.
Dependencies are inferred from the claim text.