Heat pump water heater

Patent metadata

Field	Value
Publication number	US-10914491-B2
Application number	US-201615084402-A
Country	US
Kind code	B2
Filing date	Mar 29, 2016
Priority date	Mar 29, 2016
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A heat pump water heater has a tank, a burner in communication with a fuel source, a flue, and a heat pump system. The heat pump system has a refrigerant path, at least a portion of which forms an evaporator in thermal communication with the flue. Another portion of the refrigerant path is in thermal communication with the water tank volume so that heat transfers from the refrigerant to the water tank volume.

First claim

What is claimed is:

1. A heat pump water heater, comprising:
a tank defining a water tank volume for retaining water;
a burner in communication with a fuel source and proximate the tank so that combustion of fuel from the source at the burner generates heat that transfers to the water tank volume;
a flue pipe defining a flue volume, the flue pipe having a first section extending from an area in which the burner is disposed to a top wall of the tank, a portion of the first section extending through the top wall of the tank, and a second section affixed to the portion of the first section extending through the top wall of the tank, the second section extending to an area ambient the tank so that the flue pipe conveys exhaust gas resulting from the combustion to the ambient area; and
a heat pump system comprising:
a refrigerant path having:
a first portion comprising a refrigerant conduit that is disposed between a pump and a condenser and configured to transfer refrigerant from the pump to the condenser, wherein at least a portion of the first portion is a coil wrapped around the second section of the flue pipe such that a wall of the coil is in direct contact with an outer surface of the second section of the flue pipe such that the portion of the first portion is in thermal communication with the second section of the flue pipe to transfer heat from the exhaust gas in the flue volume to the refrigerant flowing through the portion of the first portion, and
a second portion in thermal communication with the tank so that heat transfers from the refrigerant flowing through the second portion to the water tank volume when the refrigerant flows through the second portion and the water tank volume retains water,

wherein the pump is disposed in the refrigerant path between an evaporator and the coil of the first portion and is actuatable to move the refrigerant through the refrigerant path.

2. The heat pump water heater as in claim 1 , having an energy factor greater than 1.0.

3. The heat pump water heater as in claim 1 , wherein the second portion comprises the condenser of the heat pump.

4. The heat pump water heater as in claim 1 , further comprising an expansion valve in the refrigerant path, and wherein the pump is disposed in the refrigerant path between the expansion valve and at least a portion of the first portion.

5. A heat pump water heater, comprising:
a tank defining a water tank volume for retaining water;
a burner in communication with a fuel source and proximate the tank so that combustion of fuel from the source at the burner generates heat that transfers to the water tank volume;
a flue pipe defining a flue volume, the flue pipe having a first section extending from an area in which the burner is disposed to a top wall of the tank, a portion of the first section extending through the top wall of the tank, and a second section affixed to the portion of the first section extending through the top wall of the tank, the second section extending to an area ambient the tank so that the flue pipe conveys exhaust gas resulting from the combustion to the ambient area; and
a heat pump system comprising:
a fan actuatable to move air in an air flow path,
a refrigerant path having:
a first portion that passes through the air flow path,
a second portion comprising a refrigerant conduit that is disposed between a pump and a condenser and configured to transfer refrigerant from the pump to the condenser, wherein at least a portion of the second portion is a coil wrapped around the second section of the flue pipe such that a wall of the coil is in direct contact with an outer surface of the second section of the flue pipe such that the portion of the second portion is in thermal communication with the second section of the flue pipe to transfer heat from the exhaust gas in the flue volume to refrigerant flowing through the portion of the second portion, and
a third portion comprising the condenser that is in thermal communication with the tank so that heat transfers from the refrigerant flowing through the third portion to the water tank volume when the refrigerant flows through the third portion and the water tank volume retains water,

wherein the pump is disposed in the refrigerant path between the first portion and the coil of the second portion and is actuatable to move refrigerant through the refrigerant path.

6. The heat pump water heater as in claim 5 , having an energy factor greater than 1.0.

7. The heat pump water heater as in claim 5 , wherein the first portion serves as an evaporator of the heat pump.

8. The heat pump water heater as in claim 5 , wherein the first portion comprises a tubing coil of an evaporator that is disposed within the air flow path, and wherein the refrigerant path comprises an expansion valve through which refrigerant flows to the evaporator.

9. The heat pump water heater as in claim 5 , wherein the third portion is adjacent an exterior surface of the tank.

10. The heat pump water heater as in claim 9 , wherein the third portion is a section of tubing wrapped around the exterior surface of the tank.

11. A heat pump water heater, comprising:
a housing having a first portion including a tank defining a water tank volume for retaining water and a second portion;
a burner in communication with a fuel source and proximate the tank so that combustion of fuel from the source at the burner generates heat that transfers to the water tank volume;
a flue pipe defining a flue volume extending from an area in which the burner is disposed to an area ambient the tank so that the flue pipe conveys exhaust gas resulting from the combustion to the ambient area; and
a heat pump system comprising:
a fan actuatable to move air across the second portion of the housing in a horizontal air flow path, the second portion of the housing including at least a portion of the flue pipe, an evaporator, and a pump,
a refrigerant path having:
a first portion comprising the evaporator disposed in the air flow path,
a second portion comprising a refrigerant conduit that is disposed between the pump and a condenser and configured to transfer refrigerant from the pump to the condenser, wherein at least a portion of the second portion is a coil wrapped around the flue pipe such that a wall of the coil is in direct contact with an outer surface of the flue pipe so that heat transfers from the exhaust gas in the flue volume to the refrigerant flowing through the portion of the second portion, and
a third portion comprising the condenser that is adjacent the tank so that heat transfers from the refrigerant flowing through the condenser to the water tank volume when the refrigerant flows through the condenser and the water tank volume retains water, and an expansion valve through which the refrigerant flows to the evaporator,

wherein the pump is disposed in the refrigerant path between the first portion and the coil of the second portion and is actuatable to move refrigerant through the refrigerant path.

12. The heat pump water heater as in claim 11 , having an energy factor greater than 1.0.

13. A method of constructing a heat pump water heater having a tank of a predetermined size that defines a water tank volume for retaining water, a burner of a predetermined power consumption, the burner being in communication with a fuel source and proximate the tank so that combustion of fuel from the source at the burner generates heat that transfers to the water tank volume, and a flue pipe defining a flue volume, the flue pipe having a first section extending from an area in which the burner is disposed to a top wall of the tank, a portion of the f

Assignees

• Rheem Mfg Co

Inventors

• Boros Jozef
• Trant Troy E
• Fard Hafez Raeisi

Classifications

• F25B2400/071

  Compressor mounted in a housing in which a condenser is integrated · CPC title

• F25B1/005

  of the single unit type (F25B1/10 takes precedence) · CPC title

• F25B2339/047

  Water-cooled condensers · CPC title

• F25B30/02

  of the compression type · CPC title

• F25B1/10

  with multi-stage compression (with cascade operation F25B7/00) · CPC title