Latent storage air-conditioning system

Claim 2

In a latent storage air-conditioning system including: an ice building storage tank; and a refrigeration system including a plurality of refrigerant evaporators in said tank, a compressor, a condenser, and control means for the compressor responsive to the compressor inlet pressure; the improvement comprising a plurality of ice building chambers disposed in said tank for the series flow of cooling liquid therethrough; an evaporator in each tank chamber disposed to form an ice bank therein surrounding the evaporator; an expansion valve for each evaporator for expanding liquid refrigerant therein; and the means associated with each expansion valve responsive to a predetermined temperature rise through said evaporator for controlling said expansion valve; a control valve in the refrigerant supply line for selectively controlling the flow of liquid refrigerant to the several evaporator expansion valves; and temperature responsive means mounted contiguous to one evaporator coil, disposed in a tank chamber between the inlet and outlet tank chambers; said temperature responsive means being responsive to the temperature of the ice or water immediately adjacent to said coil and to the temperature of refrigerant within the coil, to selectively open and close said refrigerant control valve.

Claim 3

An air-conditioning system as set forth in claim 1 including at least one fan means for flowing cooling air across said condenser; and the means responsive to a predetermined high pressure at the compressor inlet for shutting off one or more of said fan means to reduce the flow of air over said condenser.

Claim 4

An air-conditioning system as set forth in claim 1 including a second temperature responsive means mounted contiguous to one evaporator coil, disposed in a tank chamber between the inlet and outlet tank chambers; said second temperature responsive means being responsive to the temperature of the ice or water immediately adjacent to its respective coil and to the temperature of refrigerant within the coil, to selectively open and close the refrigerant control valve; said first named and said second temperature responsive means being responsive to different preselected temperatures; third temperature responsive means responsive to atmospheric temperature; and control means operated by said third temperature responsive means for alternatively connecting said first named and said second temperature responsive means to operate said refrigerant control valve.

Claim 5

An air-conditioning System as set forth in claim 1 wherein each of said expansion valves is a thermal expansion valve having a temperature responsive power element; and wherein said expansion valve temperature responsive means includes a temperature sensing bulb mounted contiguous to its respective evaporator coil adjacent to the suction end thereof.

Claim 6

An air-conditioning system as set forth in claim 1 a second control valve for selectively controlling the flow of liquid refrigerant to a sub-group of expansion valves, less than the total number of expansion valves, whereby refrigerant is expanded through only a portion of the evaporator coils; and pressure responsive control means, responsive to a predetermined high suction pressure for closing said second control valve, and responsive to a predetermined lower suction pressure for reopening said second control valve.

Claim 7

In a method for cooling a building structure where cooling loads fluctuate widely, including the steps: providing a plurality of local cooling units in said structure; providing a chilled water storage tank; circulating chilled water between said tank and the several local cooling units in response to demand from the respective local units; providing a refrigeration system including a plurality of refrigerant evaporators in said tank, a compressor, and a condenser for building ice in said tank; and controlling the normal operation of the refrigeration system compressor in response to the compressor inlet pressure; the improvement comprising: providing a plurality of individual evaporator coils in said storage tank; placing said evaporators in serially connected flow chambers within said storage tank; providing a separate expansion valve for each of said evaporator coils; controlling each expansion valve in response to the temperature rise of the refrigerant flowing through its respective evaporator coil; and controlling the flow of refrigerant to the several evaporator expansion valves in response to a control temperature which is a function of the medium immediately surrounding one evaporator coil in an intermediate one of said serially connected flow chambers and of the suction pressure of said one evaporator coil.

Claim 8

In a method for cooling a building structure where cooling loads fluctuate widely, including the steps: providing a plurality of local cooling units in said structure; providing a chilled water storage tank; circulating chilled water between said tank and the several local cooling units in response to demand from the respective local units; providing a refrigeration system including a plurality of refrigerant evaporators in said tank, a compressor, and a condenser for building ice in said tank; and controlling the normal operation of the refrigeration system compressor in response to the compressor inlet pressure; the improvement comprising: providing a plurality of individual evaporator coils in said storage tank; placing said evaporators in serially connected flow chambers within said storage tank; providing a separate expansion valve for each of said evaporator coils; controlling each expansion valve in response to the temperature rise of the refrigerant flowing through its respective evaporator coil; and controlling the flow of refrigerant to the several evaporator expansion valves in response to a control temperature which is a function of the medium immediately surrounding one evaporator coil in an intermediate one of said serially connected flow chambers and of the suction pressure of said one evaporator coil.

Claim 9

The method set forth in claim 6, including the steps: providing a first temperature responsive control for controlling the flow of refrigerant to said expansion valves responsive to a first predetermined control temperature spread at an evaporator coil; providing a second temperature responsive control for controlling the flow of refrigerant to said expansion valves responsive to a second predetermined control temperature spread at an evaporator coil; connecting said first and second temperature responsive controls alternatively to a flow control valve actuated through an alternating relay; and controlling the condition of said alternating relay in response to the temperature of the ambient atmosphere.

Claim 10

The method set forth in claim 6, including the steps: shutting off the flow of refrigerant to a portion of said evaporator coils in response to a predetermined pressure at the compressor inlet which is above the normal inlet pressure range for the compressor.

Claim 11

The method set forth in claim 6, including the steps: flowing the refrigerant through a heat exhanger placed within the water circulating in said storage tank prior to delivery to said expansion valves.

Claim 12

The method set forth in claim 6, including the steps: providing an air-cooled condenser; providing at least one forced air means for effecting the flow of air through said condenser; and rendering inoperative at least one of said forced air means in response to a predetermined compressor discharge pressure which is below the normal discharge pressure range for the compressor.