EP-4741736-A1 - SELECTIVELY OPERABLE HEATING AND COOLING SYSTEM AND METHOD OF OPERATING THEREOF

EP4741736A1EP 4741736 A1EP4741736 A1EP 4741736A1EP-4741736-A1

Abstract

A heating and cooling system including a first heat transfer circuit that includes a first heat exchanger and a second heat exchanger; a second heat transfer circuit that includes a third heat exchanger and a fourth heat exchanger; a coolant loop; and a controller. The controller selectively operates the heating and cooling system in: a heating mode, in which the heating and cooling system is configured to operate the first heat transfer circuit and the second heat transfer circuit in a cascaded operation to heat a first process fluid via heat transfer with the first heat exchanger, and a cooling mode, in which the heating and cooling system is configured to operate the first heat transfer circuit and the second heat transfer circuit in parallel operation to both provide cooling to a second process fluid via heat transfer with the fourth heat exchanger and the second heat exchanger.

Inventors

KEMPER, Daniel S
KEYS, Daryl
GURU, Bhavana Depuru
GARBERS, Ben R

Assignees

Trane International Inc.

Dates

Publication Date: 20260513
Application Date: 20251111

Claims (15)

A heating and cooling system (100) comprising: a first heat transfer circuit (110, 210, 510), wherein the first heat transfer circuit comprises a first compressor (112), a first heat exchanger (114, 214, 514), and a second heat exchanger (118, 218, 518); a second heat transfer circuit (120, 220, 520), wherein the second heat transfer circuit comprises a second compressor (122), a third heat exchanger (124, 224, 524), and a fourth heat exchanger (128, 228, 528); a coolant loop (130, 230, 530) including a coolant, the coolant loop configured to thermally communicate thermal energy between the second heat exchanger of the first heat transfer circuit and the third heat exchanger of the second heat transfer circuit; and a controller (170), wherein the controller is configured to selectively operate the heating and cooling system in: a heating mode, wherein the heating and cooling system is configured to operate the first heat transfer circuit and the second heat transfer circuit in a cascaded operation to heat a first process fluid via heat transfer with the first heat exchanger, wherein the coolant loop is configured to thermally communicate the thermal energy between the third heat exchanger of the second heat transfer circuit and the second heat exchanger of the first heat transfer circuit, and a cooling mode, wherein the heating and cooling system is configured to operate the first heat transfer circuit and the second heat transfer circuit in parallel operation to both provide cooling to a second process fluid via heat transfer with the fourth heat exchanger and the second heat exchanger.
The heating and cooling system of claim 1, wherein the third heat exchanger of the second heat transfer circuit is configured to selectively receive cooling fluid in the cooling mode or the coolant from the coolant loop in the heating mode.
The heating and cooling system of any one of claims 1-2, wherein the first heat exchanger of the first heat transfer circuit is configured to selectively receive cooling fluid in the cooling mode or the first process fluid in the heating mode, or wherein the first heat exchanger of the first heat transfer circuit and/or the third heat exchanger of the second heat transfer circuit is a dual-bundled heat exchanger, or wherein the first heat exchanger of the first heat transfer circuit and/or the third heat exchanger of the second heat transfer circuit includes an auxiliary heat exchanger.
The heating and cooling system of any one of claims 1-3, wherein the coolant loop includes one or more valves for controlling a flow of the coolant through the coolant loop, and the controller is configured to operate the one or more valves to selectively provide either the coolant to the second heat exchanger in the heating mode or the second process fluid to the second heat exchanger in the cooling mode.
The heating and cooling system of any one of claims 1-4, wherein the heating and cooling system is a hydronic system, and the first process fluid is heating water and the second process fluid is chilled water.
The heating and cooling system of any one of claims 1-5, further comprising a cooling fluid loop including one or more valves, wherein the controller is configured to operate the one or more valves to supply cooling fluid to the first heat exchanger of the first heat transfer circuit and the third heat exchanger of the second heat transfer circuit in the cooling mode.
The heating and cooling system of any one of claims 1-6, wherein the coolant is at least one of: ethylene glycol, propylene glycol, water, and a brine solution.
A heating, ventilation, air conditioning, and refrigeration (HVACR) system (200, 500) comprising: a hydronic system comprising a first process fluid and a second process fluid for conditioning one or more spaces; a first heat transfer circuit (110, 210, 510), wherein the first heat transfer circuit comprises a first compressor (112), a first heat exchanger (114, 214, 514), and a first chiller (218, 518), wherein the first heat exchanger is configured to selectively exchange heat with the first process fluid, wherein the first process fluid further exchanges heat with a heating load (240) in the one or more spaces, or exchanges heat with cooling fluid; a second heat transfer circuit (120, 220, 520), wherein the second heat transfer circuit comprises a second compressor (122), a cascade heat exchanger (224, 524), and a second chiller (228, 528); wherein the second chiller is configured to exchange heat between the second process fluid, wherein the second process fluid further exchanges heat with a cooling load (250); a coolant loop (130, 230, 530) including a coolant, the coolant loop configured to thermally communicate thermal energy between the first chiller of the first heat transfer circuit and the cascade heat exchanger of second heat transfer circuit; and a controller (170), wherein the controller is configured to selectively operate the HVACR system in: a heating mode, wherein the HVACR system is configured to operate the first heat transfer circuit and the second heat transfer circuit in a cascaded operation to heat the first process fluid via heat transfer with the first heat exchanger, wherein the coolant loop is configured to thermally communicate the thermal energy between the cascade heat exchanger of the second heat transfer circuit and the first chiller of the first heat transfer circuit, and a cooling mode, wherein the HVACR system is configured to operate the first heat transfer circuit and the second heat transfer circuit in a parallel operation to provide cooling to the second process fluid via heat transfer with the first chiller and the second chiller, wherein the first heat exchanger is configured to exchange heat with the cooling fluid.
The HVACR system of claim 8, wherein the cascade heat exchanger of the second heat transfer circuit is configured to selectively receive the cooling fluid or the coolant from the coolant loop.
The HVACR system of any one of claims 8-9, wherein the first heat exchanger of the first heat transfer circuit and/or the cascade heat exchanger of the second heat transfer circuit is a dual-bundled heat exchanger, or wherein the first heat exchanger of the first heat transfer circuit and/or the cascade heat exchanger of the second heat transfer circuit includes an auxiliary heat exchanger.
The HVACR system of any one of claims 8-10, wherein the coolant is at least one of: ethylene glycol, propylene glycol, water, and a brine solution.
The HVACR system of any one of claims 8-11, wherein the cooling fluid is provided via a cooling fluid loop including one or more valves, wherein the controller is configured to operate the one or more valves to supply the cooling fluid to the first heat exchanger of the first heat transfer circuit and the cascade heat exchanger of the second heat transfer circuit in the cooling mode.
The HVACR system of any one of claims 9-12, wherein the coolant loop includes one or more valves for controlling a flow of the coolant through the coolant loop, and the controller is configured to operate the one or more valves to selectively provide either the coolant to the first chiller in the heating mode or the second process fluid to the first chiller in the cooling mode.
A method for heating and/or cooling a system, the system comprising a first heat transfer circuit, wherein the first heat transfer circuit comprises a first compressor, a first heat exchanger, and a second heat exchanger; a second heat transfer circuit, wherein the second heat transfer circuit comprises a second compressor, a third heat exchanger, and a fourth heat exchanger; a coolant loop including a coolant; and a controller, the method comprising selectively operating the system in either one of the following modes: operating the system in a heating mode by operating the first heat transfer circuit and the second heat transfer circuit in a cascaded operation to heat a first process fluid via heat transfer with the first heat exchanger, wherein the operating the system in the heating mode includes thermally communicating, via the coolant loop, thermal energy from the third heat exchanger of the second heat transfer circuit and the second heat exchanger of the first heat transfer circuit; or operating the system in a cooling mode by operating the first heat transfer circuit and the second heat transfer circuit in parallel operation to provide cooling to a second process fluid, wherein the operating the system in the cooling mode includes providing the second process fluid to the fourth heat exchanger and the second heat exchanger.
The method of claim 14, further comprising selectively controlling flow of the coolant through the coolant loop to provide either the coolant to the second heat exchanger of the first heat transfer circuit in the heating mode or the second process fluid to the second heat exchanger in the cooling mode.

Description

FIELD This disclosure relates generally to heating and cooling systems that are selectively operable in a cascaded operation or a parallel operation. More specifically, the disclosure relates to a heating, ventilation, air conditioning, and refrigeration (HVACR) system to condition a space and methods for operating heat transfer circuits in cascaded operation or parallel operation. BACKGROUND A heating and cooling system can be used to heat and cool one or more process fluids for a variety of applications. For example, the heating and cooling system can be used to heat a heating load and/or cool a cooling load for industrial processes, such as, heating and/or cooling gas or liquid flows to maintain reaction temperatures or temperature setpoints, cooling industrial waste, providing heat to replace gas boilers, providing refrigeration, or the like. The heating and cooling system can also be used to condition a space, for example, an HVACR system can be used to provide heating and/or provide cooling for the conditioned space. In some cases, the HVACR system can be a hydronic system that includes a heat transfer circuit to provide a liquid process fluid, for example, water, a brine solution, or a glycol solution, as a heat-transfer medium to condition a space in a building or occupied space. The HVACR system often includes a heat transfer circuit system that can include one or more compressors, expanders, a condenser, an evaporator, fans, filters, dampers, circulation pumps, and various other equipment, in which the compressor(s), the condenser, the expander, and the evaporator are fluidly connected. SUMMARY This disclosure relates generally to heating and cooling systems that are selectively operable in a cascaded operation or a parallel operation. More specifically, the disclosure relates to a heating, ventilation, air conditioning, and refrigeration (HVACR) system to condition a space and methods for operating heat transfer circuits in cascaded operation or parallel operation. The HVACR system can be a hydronic system in which thermal energy in a heat transfer circuit is exchanged with process fluid(s), e.g., ethylene glycol, propylene glycol, water, a brine solution, or the like, which is used to condition a space. For example, when providing heating to the conditioned space, the heat generated from the compression of a working fluid in the heat transfer circuit can be used to reject thermal energy into the process fluid that is circulated in a heating water circuit of the hydronic system to condition the space. Similarly, for providing cooling to the conditioned space, the HVACR system can extract heat from a second process fluid that is circulated in a chilled water circuit of the hydronic system to cool the process fluid to condition the space. In an embodiment, a heating and cooling system is provided. The heating and cooling system includes a first heat transfer circuit, in which the first heat transfer circuit includes a first compressor, a first heat exchanger, and a second heat exchanger; a second heat transfer circuit, in which the second heat transfer circuit includes a second compressor, a third heat exchanger, and a fourth heat exchanger; a coolant loop including a coolant, the coolant loop configured to thermally communicate thermal energy between the second heat exchanger of the first heat transfer circuit and the third heat exchanger of the second heat transfer circuit; and a controller. The controller is configured to selectively operate the heating and cooling system in: a heating mode, in which the heating and cooling system is configured to operate the first heat transfer circuit and the second heat transfer circuit in a cascaded operation to heat a first process fluid via heat transfer with the first heat exchanger, in which the coolant loop is configured to thermally communicate the thermal energy between the third heat exchanger of the second heat transfer circuit and the second heat exchanger of the first heat transfer circuit, and a cooling mode, in which the heating and cooling system is configured to operate the first heat transfer circuit and the second heat transfer circuit in parallel operation to both provide cooling to a second process fluid via heat transfer with the fourth heat exchanger and the second heat exchanger. In another embodiment, a heating, ventilation, air conditioning, and refrigeration (HVACR) system is provided. The HVACR system includes a hydronic system including a first process fluid and a second process fluid for conditioning one or more spaces; a first heat transfer circuit, in which the first heat transfer circuit comprises a first compressor, a first heat exchanger, and a first chiller, in which the first heat exchanger is configured to selectively exchange heat with the first process fluid, and the first process fluid further exchanges heat with a heating load in the one or more spaces, or exchanges heat with cooling fluid; a second heat transfer circu