CN-122015311-A - Cascade heating/cooling system with intermediate loop heat exchange

Abstract

A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a first heat transfer loop, a second heat transfer loop, a fluid loop, a heat exchanger, and a controller. The fluid circuit is located between the first heat transfer circuit and the second heat transfer circuit, and the heat exchanger is connected to the fluid circuit. The controller is configured to determine an operating parameter of the HVACR system, and control a heat exchanger to remove heat from the fluid circuit when the operating parameter is above a first threshold.

Inventors

• Li R. Klein
• Darryl Keith

Assignees

• 特灵国际有限公司

Dates

Publication Date

20260512

Application Date

20251111

Priority Date

20241111

Claims (20)

1. 1. A heating, ventilation, air conditioning, and refrigeration (HVACR) system, the HVACR system comprising: A first heat transfer circuit; a second heat transfer circuit; A fluid circuit located between the first heat transfer circuit and the second heat transfer circuit; A heat exchanger connected to the fluid circuit, and The controller is used for controlling the operation of the controller, The controller is configured to: determining an operating parameter of the system, and When the operating parameter is above a first threshold, the heat exchanger is controlled to remove heat from the fluid circuit.
2. 2. The HVACR system of claim 1, wherein the controller is further configured to control the heat exchanger to add heat to the fluid circuit when the operating parameter is below a second threshold.
3. 3. The HVACR system of claim 1 wherein the first heat transfer circuit includes a fluid inlet configured to receive fluid from the fluid circuit and a fluid outlet for flowing fluid out to the fluid circuit, The first heat transfer circuit is configured to add heat to the fluid circuit.
4. 4. The HVACR system of claim 3 further comprising a cooling circuit configured to add heat to the fluid circuit via the first heat transfer circuit, the cooling circuit being a heat source of the HVACR system.
5. 5. The HVACR system of claim 1 wherein the second heat transfer circuit includes a fluid inlet configured to receive fluid from the fluid circuit and a fluid outlet for flowing fluid out to the fluid circuit, The second heat transfer circuit is configured to remove heat from the fluid circuit.
6. 6. The HVACR system of claim 5, further comprising: A heating circuit configured to remove heat from the fluid circuit via the second heat transfer circuit, the heating circuit being a heat reservoir of the HVACR system.
7. 7. The HVACR system of claim 1, further comprising a flow control device, The controller is further configured to control the flow control device to direct fluid flow from the fluid circuit to the heat exchanger when the operating parameter is above the first threshold.
8. 8. The HVACR system of claim 7, wherein the controller is further configured to control the flow control device to direct fluid flow from the fluid circuit to the heat exchanger when the operating parameter is below a second threshold.
9. 9. The HVACR system of claim 8, wherein the controller is further configured to control the flow control device to block fluid flow from the fluid circuit to the heat exchanger when the operating parameter is equal to or below the first threshold and equal to or above the second threshold.
10. 10. The HVACR system of claim 1, wherein the operating parameter is a temperature of a fluid flow downstream of the first heat transfer circuit and upstream of the second heat transfer circuit.
11. 11. A method of operating a heating, ventilation, air conditioning, and refrigeration (HVACR) system including a first heat transfer circuit, a second heat transfer circuit, a fluid circuit between the first heat transfer circuit and the second heat transfer circuit, a heat exchanger connected to the fluid circuit, and a controller, the method comprising: Determining operating parameters of the HVACR system, and When the operating parameter is above a first threshold, the heat exchanger is controlled to remove heat from the fluid circuit.
12. 12. The method of claim 11, the method further comprising: the heat exchanger is controlled to add heat to the fluid circuit when the operating parameter is below a second threshold.
13. 13. The method of claim 11, wherein the first heat transfer circuit comprises a fluid inlet configured to receive fluid from the fluid circuit and a fluid outlet for flowing fluid out to the fluid circuit, The first heat transfer circuit is configured to add heat to the fluid circuit.
14. 14. The method of claim 13, wherein the HVACR system further comprises a cooling circuit configured to add heat to the fluid circuit via the first heat transfer circuit, the cooling circuit being a heat source of the HVACR system.
15. 15. The method of claim 11, wherein the second heat transfer circuit comprises a fluid inlet configured to receive fluid from the fluid circuit and a fluid outlet for flowing fluid out to the fluid circuit, The second heat transfer circuit is configured to remove heat from the fluid circuit.
16. 16. The method of claim 15, wherein the HVACR system further comprises a heating circuit configured to remove heat from the fluid circuit via the second heat transfer circuit, the heating circuit being a heat reservoir of the HVACR system.
17. 17. The method of claim 11, wherein the HVACR system further comprises a flow control device, The method further includes controlling the flow control device to direct fluid flow from the fluid circuit to the heat exchanger when the operating parameter is above the first threshold.
18. 18. The method of claim 17, further comprising controlling the flow control device to direct fluid flow from the fluid circuit to the heat exchanger when the operating parameter is below a second threshold.
19. 19. The method of claim 18, further comprising controlling the flow control device to block fluid flow from the fluid circuit to the heat exchanger when the operating parameter is at or below the first threshold and at or above the second threshold.
20. 20. The method of claim 11, wherein the operating parameter is a temperature of a fluid flow downstream of the first heat transfer loop and upstream of the second heat transfer loop.

Description

Cascade heating/cooling system with intermediate loop heat exchange Technical Field Embodiments described herein relate generally to systems and methods for thermal energy control for heating, ventilation, air conditioning, and refrigeration (HVACR) systems. More specifically, embodiments described herein relate to maintaining a desired temperature in an intermediate loop of a cascaded heating and/or cooling HVACR system under different modes of system operation. Background Heating, ventilation, air conditioning, and refrigeration (HVACR) systems may include one or more heat transfer circuits. The heat transfer circuit may include one or more compressors, condensers, evaporators, fans, filters, dampers, and various other devices. The one or more compressors, condensers, expansion devices, and evaporators are fluidly connected. The heat transfer circuit may be a heat pump, a chiller, or the like. Disclosure of Invention Features in embodiments disclosed herein may enable and/or extend the application of HVACR systems including cascaded heat transfer circuits, such as gas compression cooler units and/or heat pump units. Features in embodiments disclosed herein may also allow for reliable, and/or long-term system operation when the operating capacities of the primary and secondary units in the cascade system are not synchronized. Features in embodiments disclosed herein may facilitate different modes of system operation, such as system start-up, stable operation, and intentional capacity mismatch (e.g., cooling dominant system operation). Features in embodiments disclosed herein may maintain a desired temperature in an intermediate loop of a cascade heating and/or cooling system under different modes of system operation. The modes include, but are not limited to, system start-up, unit start-up(s), individual unit capacity change (e.g., loading, unloading, etc.), intentional cooling dominant operation, intentional heating dominant operation, unit shut-down(s), and/or system shut-down. Features in embodiments disclosed herein may prevent unacceptable temperature transitions from occurring (during one or more modes of operation), which may negatively impact system operation (e.g., supply of heating or cooling), resulting in unstable system and/or unit operation(s), and impact short-term or long-term reliability of the unit(s). In an example embodiment, a heating, ventilation, air conditioning, and refrigeration (HVACR) system is provided. The HVACR system includes a first heat transfer circuit, a second heat transfer circuit, a fluid circuit between the first heat transfer circuit and the second heat transfer circuit, a heat exchanger connected to the fluid circuit, and a controller. The controller is configured to determine an operating parameter of the system, and when the operating parameter is above a first threshold, control the heat exchanger to remove heat from the fluid circuit. In an example embodiment, a method of operating a heating, ventilation, air conditioning and refrigeration (HVACR) system is provided. The HVACR system includes a first heat transfer circuit, a second heat transfer circuit, a fluid circuit between the first heat transfer circuit and the second heat transfer circuit, a heat exchanger connected to the fluid circuit, and a controller. The method includes determining an operating parameter of the system, and controlling the heat exchanger to remove heat from the fluid circuit when the operating parameter is above a first threshold. Drawings The drawings illustrate various embodiments of the systems, methods, and illustrate embodiments of various other aspects of the present disclosure. Those of ordinary skill in the art will appreciate that the element boundaries (e.g., blocks, groups of blocks, or other shapes) illustrated in the figures represent one example of boundaries. It is possible that in some examples, one element may be designed as multiple elements, or multiple elements may be designed as one element. In some examples, elements shown as internal components of one element may be implemented as external components in another element, and vice versa. Non-limiting and non-exhaustive descriptions are described with reference to the following figures. The components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles. In the following "detailed description," examples are described merely as illustrations, as various changes and modifications may become apparent to those skilled in the art from the following "detailed description. FIG. 1 shows a schematic diagram of a controller subsystem arranged in accordance with at least some embodiments described herein. Fig. 2A illustrates a schematic diagram of a cascaded HVACR system arranged in accordance with at least some embodiments described herein. Fig. 2B illustrates a schematic diagram of a cascaded HVACR system arranged in accordance with at least some embodiments described