US 11,781,792 B2
Air-cooled chiller with heat recovery system
Geoffrey Lutz, Montluel (FR); and Alexis Guy, Montluel (FR)
Assigned to CARRIER CORPORATION, Palm Beach Gardens, FL (US)
Filed by Carrier Corporation, Palm Beach Gardens, FL (US)
Filed on Dec. 16, 2021, as Appl. No. 17/552,430.
Claims priority of application No. 20215623 (EP), filed on Dec. 18, 2020.
Prior Publication US 2022/0196301 A1, Jun. 23, 2022
Int. Cl. F25B 41/20 (2021.01); F25B 13/00 (2006.01)
CPC F25B 41/20 (2021.01) [F25B 13/00 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An air-cooled chiller comprising:
a compressor;
a cooler;
a heat recovery heat exchanger, wherein the heat recovery heat exchanger is connected between an output of the compressor and an input header of an air heat exchanger;
the air heat exchanger comprising:
a first coil and a second coil;
wherein the input header is connected to respective inlets of the first and second coils;
wherein an output header is connected to respective outlets of the first and second coils;
a solenoid valve located in the input header to divide the input header into a first portion and a second portion, wherein the first coil inlet is connected to the first portion and the second coil inlet is connected to the second portion, wherein the solenoid valve selectively controls refrigerant flow into the second portion, such that when the solenoid valve is open, refrigerant is allowed to flow through both the first and second coils in parallel and, when the solenoid valve is closed, refrigerant is prevented from flowing into the second coil;
a controller configured to control the solenoid valve; and
a second valve located in the output header to divide the output header into a first portion and a second portion, wherein the first coil outlet is connected to the first portion and the second coil outlet is connected to the second portion, and wherein the second valve is configured to prevent refrigerant flow from the first portion into the second portion of the outlet header;
wherein the first portion of the input header is configured to receive fluid from the compressor output, via the heat recovery heat exchanger; and the first portion of the outlet header is connected to one or more lines for returning fluid to the compressor.
 
10. A two-circuit air-cooled chiller comprising
a first circuit and a second circuit, each comprising an air-cooled chiller according to claim 1; and
wherein the two-circuit air-cooled chiller is configured such that the or each solenoid valve in the inlet header of the first circuit is controllable independently of the or each solenoid valve in the inlet header of the second circuit.
 
11. A method of operating the air-cooled chiller according to claim 1, the method comprising:
flowing a refrigerant through the air heat exchanger;
detecting a fluid temperature of a fluid flow flowing out of the heat recovery heat exchanger; and
when the temperature of the fluid flowing out of the heat recovery heat exchanger is below a predetermined threshold, using the controller to close at least one solenoid valve in the inlet header to prevent refrigerant flow through at least one of the coils.
 
13. A method of retrofitting a serial concept air-cooled chiller to provide the air cooled chiller according to claim 1, wherein the serial concept air-cooled chiller comprises an inlet header, an outlet header, and at least first and second coils connected between the inlet header and outlet header, the method comprising:
installing a solenoid valve in the inlet header at a location between an inlet of the first coil and an inlet of the second coil, such that the solenoid valve may selectively control refrigerant flow to the inlet of the second coil;
installing a second valve in the outlet header at a location between an outlet of the first coil and an outlet of the second coil; and
connecting a controller to the solenoid valve to control the solenoid valve.