US 12,405,022 B2
Energy efficient heat pump with counterflow heat transfer arrangement
Andrew Leroy Hjortland, Stoughton, WI (US)
Assigned to TYCO FIRE & SECURITY GMBH, Neuhausen am Rheinfall (CH)
Filed by Johnson Controls Tyco IP Holdings LLP, Milwaukee, WI (US)
Filed on Apr. 26, 2023, as Appl. No. 18/307,668.
Claims priority of provisional application 63/336,173, filed on Apr. 28, 2022.
Prior Publication US 2023/0349581 A1, Nov. 2, 2023
Int. Cl. F24F 11/67 (2018.01); F24F 1/10 (2011.01); F25B 1/00 (2006.01)
CPC F24F 11/67 (2018.01) [F24F 1/10 (2013.01); F25B 1/00 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A heat pump for a heating, ventilation, and air conditioning (HVAC) system, comprising:
a compressor system configured to direct a working fluid along a working fluid circuit of the heat pump, wherein the compressor system comprises:
a first compressor configured to direct the working fluid along a first portion of the working fluid circuit comprising a first expansion device to operate the heat pump in a cooling mode; and
a second compressor configured to direct the working fluid along a second portion of the working fluid circuit comprising a second expansion device to operate the heat pump in a heating mode;
a heat exchanger disposed along the working fluid circuit, wherein the second compressor is configured to direct, during operation of the heat pump in the heating mode, the working fluid through two or more passes of the heat exchanger in a first sequential order to place the working fluid in a counterflow heat transfer arrangement with a supply air flow directed across the two or more passes of the heat exchanger in a second sequential order opposite the first sequential order, and the heat exchanger is configured to heat the supply air flow during operation of the heat pump in the heating mode;
a first solenoid valve disposed along the working fluid circuit upstream of the first compressor relative to flow of the working fluid along the working fluid circuit, wherein the first solenoid valve is configured to control flow of the working fluid into the first compressor;
a second solenoid valve disposed along the working fluid circuit upstream of the second compressor relative to flow of the working fluid along the working fluid circuit, wherein the second solenoid valve is configured to control flow of the working fluid into the second compressor; and
a controller communicatively coupled to the first compressor, the second compressor, the first solenoid valve, and the second solenoid valve, wherein the controller is configured to:
open the first solenoid valve, close the second solenoid valve, operate the first compressor, and suspend operation of the second compressor in the cooling mode; and
open the second solenoid valve, close the first solenoid valve, operate the second compressor, and suspend operation of the first compressor in the heating mode,
wherein the heat pump is configured to discharge the supply air flow toward a conditioned space.