Heat engine system including an integrated cooling circuit

• US 10,024,198 B2
• Filed: 08/08/2016
• Issued: 07/17/2018
• Est. Priority Date: 08/13/2015
• Status: Active Grant

• Current Assignee: Echogen Power Systems, LLC
• Original Assignee: Echogen Power Systems, LLC
• Inventors: Held, Timothy, Miller, Jason D.
• Primary Examiner(s): GONZALEZ, JULIO CESAR
• Application Number:
  US15/231,047
• Publication Number:
  US 20170130614A1
• Time in Patent Office: 708 Days
• Field of Search: 290 52, 290 40 C, 290 40 R, 60728, 60692, 60651, 60671, 622384
• CPC Class Codes: F01D 15/08 Adaptations for driving, or combinations with, pumps
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F01K 13/006 Auxiliaries or details not otherwise provided for
• CPC Class Codes: F01K 23/02 the engine cycles being thermally coupled
• CPC Class Codes: F01K 25/04 the fluid being in different phases, e.g. foamed
• CPC Class Codes: F01K 25/08 using special vapours
• CPC Class Codes: F01K 27/02 Plants modified to use their waste heat, other than that of exhaust, e.g. engine-friction heat
• CPC Class Codes: F28B 1/00 Condensers in which the steam or vapour is separate from the cooling medium by walls, e.g. surface condenser
• CPC Class Codes: F28B 7/00 Combinations of two or more condensers, e.g. provision of reserve condenser
• CPC Class Codes: H02K 7/1823 structurally associated with turbines or similar engines

Abstract

A heat engine system and a method for cooling a fluid stream in thermal communication with the heat engine system are provided. The heat engine system may include a working fluid circuit configured to flow a working fluid therethrough, and a cooling circuit in fluid communication with the working fluid circuit and configured to flow the working fluid therethrough. The cooling circuit may include an evaporator in fluid communication with the working fluid circuit and configured to be in fluid communication with the fluid stream. The evaporator may be further configured to receive a second portion of the working fluid from the working fluid circuit and to transfer thermal energy from the fluid stream to the second portion of the working fluid.

Claims

1. A heat engine system, comprising:

a working fluid circuit configured to flow a working fluid therethrough, comprising;

a waste heat exchanger configured to be in fluid communication and in thermal communication with a heat source stream, and to transfer thermal energy from the heat source stream to the working fluid;

an expander disposed downstream from and in fluid communication with the waste heat exchanger and configured to convert a pressure drop in the working fluid to mechanical energy;

a recuperator disposed upstream of and in fluid communication with the waste heat exchanger and disposed downstream from and in fluid communication with the expander;

a pump disposed upstream of and in fluid communication with the recuperator and configured to pressurize and circulate at least a first portion of the working fluid within the working fluid circuit; and

a first condenser disposed upstream of and in fluid communication with the pump and disposed downstream from and in fluid communication with the recuperator; and

a cooling circuit in fluid communication with the working fluid circuit and configured to flow the working fluid therethrough, the cooling circuit comprising;

an evaporator in fluid communication with the working fluid circuit and configured to be in fluid communication with a fluid stream, the evaporator further configured to receive a second portion of the working fluid from the working fluid circuit and to transfer thermal energy from the fluid stream to the second portion of the working fluid,

an expansion valve disposed upstream of and in fluid communication with the evaporator and configured to receive the second portion of the working fluid from the working fluid circuit and to reduce the pressure and temperature of the second portion of the working fluid flowing therethrough,

a compressor disposed downstream from and in fluid communication with the evaporator and disposed upstream of and in fluid communication with the first condenser, and

a second condenser disposed downstream from and in fluid communication with the pump and disposed upstream of and in fluid communication with the expansion valve, the second condenser configured to receive and cool the second portion of the working fluid discharged from the pump of the working fluid circuit, wherein

the cooling circuit is in fluid communication with the working fluid circuit upstream of the first condenser, and the first condenser is configured to receive and flow therethrough the first portion and the second portion of the working fluid, and

the cooling circuit is in fluid communication with the working fluid circuit at a junction downstream from the pump and upstream of the recuperator, and the recuperator is configured to receive the first portion of the working fluid.

2. The heat engine system of claim 1, further comprising a generator coupled with the expander via a driveshaft, wherein the generator is configured to convert the mechanical energy into electrical energy.

3. The heat engine system of claim 2, wherein the pump is coupled with the expander and the generator via the driveshaft, the expander configured to drive the pump via the driveshaft.

4. The heat engine system of claim 1, wherein the working fluid comprises carbon dioxide in a subcritical state and a supercritical state in different locations of the working fluid circuit and the cooling circuit.

5. A heat engine system comprising:

a working fluid circuit configured to flow a working fluid therethrough, the working fluid comprising carbon dioxide and the working fluid circuit comprising;

a waste heat exchanger configured to be in fluid communication and in thermal communication with a heat source stream, and to transfer thermal energy from the heat source stream to the working fluid;

an expander configured to receive the working fluid from the waste heat exchanger and to convert a pressure drop in the working fluid to mechanical energy;

a pump configured to pressurize and circulate a least a first portion of the working fluid within the working fluid circuit, the pump further being configured to be driven by the expander via a driveshaft;

a recuperator configured to receive the working fluid from the expander and the first portion of the working fluid from the pump, and to transfer thermal energy from the working fluid received from the expander to the first portion of the working fluid received from the pump; and

a first condenser disposed downstream from the recuperator and upstream of the pump; and

a cooling circuit configured to be in fluid communication with the working fluid circuit and to flow the working fluid therethrough, the cooling circuit comprising;

an expansion valve configured to receive a second portion of the working fluid from the working fluid circuit and to reduce the pressure and temperature of the second portion of the working fluid flowing therethrough;

an evaporator configured to be in fluid communication with a fluid stream, the evaporator further configured to receive the second portion of the working fluid from the expansion valve and to transfer thermal energy from the fluid stream to the second portion of the working fluid;

a compressor configured to receive the second portion of the working fluid from the evaporator and to compress the second portion of the working fluid; and

a second condenser configured to receive and cool the second portion of the working fluid from the working fluid circuit, wherein

the cooling circuit is configured to be in fluid communication with the working fluid circuit at a first junction downstream from the pump and upstream of the recuperator, and

the cooling circuit is configured to be in fluid communication with the working fluid circuit at a second junction upstream of the first condenser, and the first condenser is configured to receive, cool, and flow therethrough the first portion and the second portion of the working fluid.

6. The heat engine system of claim 5, further comprising a generator coupled with the expander via the driveshaft, wherein the generator is configured to convert the mechanical energy into electrical energy.

7. A method for cooling a fluid stream in thermal communication with a heat engine system, comprising:

transferring thermal energy from a heat source stream to a working fluid in a waste heat exchanger of a working fluid circuit of the heat engine system;

expanding the working fluid in an expander in fluid communication with the waste heat exchanger;

circulating at least a first portion of the working fluid in the working fluid circuit via a pump driven by the expander;

cooling the working fluid in a first condenser disposed upstream of the pump in the working fluid circuit;

expanding a second portion of the working fluid in an expansion valve in a cooling circuit, wherein

the cooling circuit is fluidly coupled with the working fluid circuit at a first junction and a second junction,

the second junction is disposed upstream of the first condenser, and

the first junction is downstream from the pump and upstream of a recuperator in fluid communication with the expander, the pump, and the waste heat exchanger;

transferring thermal energy from the fluid stream to the second portion of the working fluid in an evaporator, thereby cooling the fluid stream;

compressing the second portion of the working fluid in a compressor disposed downstream from the evaporator in the cooling circuit;

combining the second portion of the working fluid and the first portion of the working fluid at the second junction; and

cooling the second portion of the working fluid in a second condenser disposed downstream from and in fluid communication with the pump and disposed upstream of and in fluid communication with the expansion valve.