HVAC system with bypass conduit

Patent metadata

Field	Value
Publication number	US-12429257-B2
Application number	US-202118029530-A
Country	US
Kind code	B2
Filing date	Sep 30, 2021
Priority date	Sep 30, 2020
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

A heating, ventilation, and/or air conditioning (HVAC) system includes a vessel configured to receive refrigerant from a condenser of the HVAC system, an evaporator configured to receive the refrigerant from the vessel, a first conduit configured to direct a first flow of the refrigerant to a first inlet of the evaporator, and a second conduit configured to direct a second flow of the refrigerant to a second inlet of the evaporator. The second inlet is above the first inlet relative to a vertical axis.

First claim

The invention claimed is:

1. A heating, ventilation, and/or air conditioning (HVAC) system, comprising:
a vessel configured to receive refrigerant from a condenser of the HVAC system;
an evaporator configured to receive the refrigerant from the vessel;
a first conduit configured to direct a first flow of the refrigerant to a first inlet of the evaporator, wherein the first inlet is disposed at a bottom section of the evaporator; and
a second conduit configured to direct a second flow of the refrigerant to a second inlet of the evaporator, wherein the second inlet is above the first inlet relative to a vertical axis.

2. The HVAC system of claim 1 , comprising a third conduit extending from the condenser to the vessel, wherein the third conduit comprises an expansion valve configured to reduce a pressure of the refrigerant directed from the condenser to the vessel to enable separation of the refrigerant into liquid refrigerant and vapor refrigerant within the vessel.

3. The HVAC system of claim 2 , comprising an outlet conduit extending from the vessel and configured to direct the liquid refrigerant from the vessel toward the evaporator, wherein each of the first conduit and the second conduit extends from the outlet conduit.

4. The HVAC system of claim 2 , comprising:
an outlet conduit configured to discharge the refrigerant from the condenser; and
an inlet conduit extending from the outlet conduit to the vessel,
wherein the first conduit extends from the outlet conduit to the evaporator to enable refrigerant bypass of the vessel, and the second conduit extends from the vessel to the evaporator.

5. The HVAC system of claim 1 , wherein the first conduit comprises a bypass valve, the HVAC system comprises a controller communicatively coupled to the bypass valve, and the controller is configured to operate the bypass valve based on an operating parameter indicative of a pressure differential within the HVAC system.

6. The HVAC system of claim 1 , wherein the evaporator is a hybrid falling film and flooded evaporator.

7. A heating, ventilation, and/or air conditioning (HVAC) system, comprising:
a vessel configured to receive refrigerant from a condenser and to separate the refrigerant received from the condenser into vapor refrigerant and liquid refrigerant;
a first conduit configured to direct a first flow of liquid refrigerant to a first inlet of an evaporator of the HVAC system, wherein the first conduit comprises a bypass valve, and the first inlet is disposed at a bottom section of the evaporator;
a second conduit configured to direct a second flow of liquid refrigerant to a second inlet of the evaporator, wherein the second inlet is above the first inlet relative to a vertical axis; and
a controller communicatively coupled to the bypass valve, wherein the controller is configured to operate the bypass valve to control a flow rate of the first flow of liquid refrigerant to the evaporator via the first conduit.

8. The HVAC system of claim 7 , comprising the evaporator, wherein the second conduit extends to a top section of the evaporator, and the controller is configured to close the bypass valve to operate the evaporator as a falling film evaporator.

9. The HVAC system of claim 7 , comprising the evaporator, wherein the second conduit comprises an expansion valve configured to reduce a pressure of the second flow of liquid refrigerant directed through the second conduit, and the controller is configured to close the expansion valve to operate the evaporator as a flooded evaporator.

10. The HVAC system of claim 7 , wherein the controller is configured to operate the bypass valve based on an operating parameter indicative of a level of the liquid refrigerant in the vessel, a liquid level of the refrigerant in the condenser, a liquid level of the refrigerant in the evaporator, a level of the second flow of liquid refrigerant in the second conduit, a pressure within the condenser, a pressure within the evaporator, a pressure within the vessel, a flow rate of the second flow of liquid refrigerant through the second conduit, a temperature within the condenser, a temperature within the evaporator, a temperature within the vessel, an ambient temperature, an amount of power supplied to a compressor of the HVAC system, a speed of the compressor, or any combination thereof.

11. The HVAC system of claim 7 , comprising the condenser and a compressor, wherein the compressor is configured to receive refrigerant from the evaporator, pressurize the refrigerant, and direct the refrigerant to the condenser.

12. The HVAC system of claim 11 , wherein the controller is configured to suspend operation of the compressor or operate the compressor at a reduced capacity based on a temperature within the condenser being below a threshold value.

13. The HVAC system of claim 11 , wherein the compressor is a first compressor configured to receive vapor refrigerant from the vessel, pressurize the vapor refrigerant, and direct the pressurized vapor refrigerant to the condenser, and the HVAC system comprises a second compressor configured to receive vapor refrigerant from the vessel, pressurize the vapor refrigerant, and direct the pressurized vapor refrigerant to the condenser.

14. A heating, ventilation, and/or air conditioning (HVAC) system, comprising:
a condenser;
an intermediate vessel configured to receive refrigerant from the condenser;
an evaporator configured to receive the refrigerant from the intermediate vessel;
a first conduit extending between the condenser and the intermediate vessel, wherein the first conduit comprises an expansion valve configured to reduce a pressure of the refrigerant directed through the first conduit to enable separation of the refrigerant into liquid refrigerant and vapor refrigerant within the intermediate vessel;
a second conduit extending between the intermediate vessel and a first inlet of the evaporator, wherein the second conduit is configured to direct the liquid refrigerant into the evaporator via the first inlet, and the first inlet is disposed at a bottom section of the evaporator; and
a third conduit extending between the intermediate vessel and a second inlet of the evaporator, wherein the second inlet is above the first inlet relative to a vertical axis, and the third conduit is configured to direct the liquid refrigerant into the evaporator via the second inlet.

15. The HVAC system of claim 14 , wherein the second conduit comprises a bypass valve configured to control a flow rate of the liquid refrigerant directed through the second conduit, and the third conduit comprises an additional expansion valve configured to reduce a pressure of the liquid refrigerant directed through the third conduit.

16. The HVAC system of claim 15 , comprising a controller communicatively coupled to the expansion valve, the additional expansion valve, and the bypass valve, wherein the controller is configured to control the expansion valve, the additional expansion valve, the bypass valve, or any combination thereof, based on an operating parameter indicative of a flow rate of the liquid refrigerant into the evaporator.

17. The HVAC system of claim 14 , comprising a fourth conduit configured to discharge the liquid refrigerant from the intermediate vessel, wherein each of the second conduit and the third conduit extends between the fourth conduit and the evaporator.

18. The HVAC system of claim 14 , wherein the first inlet is positioned beneath a tube bundle within the evaporator relative to the vertical axis, and the second inlet is positioned above

Assignees

• Johnson Controls Tyco IP Holdings LLP
• Tyco Fire & Security Gmbh

Inventors

• Bradshaw David Andrew
• Nelson Cameron Stuart
• Schreiber Jeb William
• Gladfelter Seth Kevin

Classifications

• F25B2600/2511

  Evaporator distribution valves · CPC title

• F25B2600/0253

  with variable speed · CPC title

• F25B2339/024

  Evaporators with refrigerant in a vessel in which is situated a heat exchanger · CPC title

• F25B2339/021

  Evaporators in which refrigerant is sprayed on a surface to be cooled · CPC title

• F25B39/028

  having distributing means · CPC title