ORGANIC MOTIVE FLUID BASED WASTE HEAT RECOVERY SYSTEM

• US 20110259010A1
• Filed: 04/22/2010
• Published: 10/27/2011
• Est. Priority Date: 04/22/2010
• Status: Active Grant

• Current Assignee: Ormat Technologies Incorporated (Ormat Industries Limited)
• Original Assignee: Ormat Technologies Incorporated (Ormat Industries Limited)
• Inventors: Bronicki, Yoram, Bronicki, Lucien Y.
• Granted Patent: US 8,752,381 B2
• Time in Patent Office: Days
• US Class Current: 60/651
• CPC Class Codes: F01K 13/02 Controlling, e.g. stopping or starting
• CPC Class Codes: F01K 23/065 the combustion taking place in an internal combustion piston engine, e.g. a diesel engine
• CPC Class Codes: F01K 23/101 Regulating means specially adapted therefor F01K23/105, F01K23/108 take precedence
• CPC Class Codes: F01K 25/08 using special vapours
• CPC Class Codes: F01K 7/18 the turbine being of multiple-inlet-pressure type
• CPC Class Codes: F22B 3/04 by drop in pressure of high-pressure hot water within pressure- reducing chambers, e.g. in accumulators steam accumulators per se F01K1/00

Abstract

The present invention provides a waste heat recovery system, comprising a closed fluid circuit through which an organic motive fluid flows, heat exchanger means for transferring heat from waste heat gases to the motive fluid, means for flashing the motive fluid which exits the heat exchanger means into a high pressure flashed vapor portion, means for flashing liquid non-flashed motive fluid producing a low pressure flashed vapor portion, a high pressure turbine module which receives said high pressure flashed vapor portion to produce power, and a low pressure turbine module which receives a combined flow of motive fluid vapor comprising the low pressure flashed vapor portion and discharge vapor from the high pressure turbine module whereby additional power is produced.

Claims

1. A waste heat recovery system, comprising a closed fluid circuit through which an organic motive fluid flows, heat exchanger means for transferring heat from waste heat gases to said motive fluid, means for flashing the motive fluid which exits said heat exchanger means into a high pressure flashed vapor portion, means for flashing liquid non-flashed motive fluid producing a low pressure flashed vapor portion, a high pressure turbine module which receives said high pressure flashed vapor portion to produce power, and a low pressure turbine module which receives a combined flow of motive fluid vapor comprising said low pressure flashed vapor portion and discharge vapor from said high pressure turbine module whereby additional power is produced.

2. The system according to claim 1, wherein the flashing means comprises a high pressure flash chamber for receiving the motive fluid exiting the heat exchanger means and producing the high pressure flashed portion, and a low pressure flash chamber for receiving a non-flashed discharge from said high pressure flash chamber and producing the low pressure flashed portion.

3. The system according to claim 2, further comprising a direct contact recuperator, a condenser for condensing discharge vapor from the low pressure turbine module, and a cycle pump for delivering at least a portion of the motive fluid condensate from said condenser to said direct contact recuperator for mixing with the high pressure turbine module discharge vapor, whereby the mixed flow produced exiting said direct contact recuperator is combined with the low pressure flashed vapor portion to produce the combined flow supplied to the low pressure turbine module.

4. The system according to claim 2, further comprising a recuperator for heating a portion of the motive fluid condensate using a portion of the low pressure turbine module vapor discharge.

5. The system according to claim 4, further comprising a preheater for preheating the recuperated condensate by means of a non-flashed discharge from the low pressure flash chamber.

6. The system according to claim 5, wherein heat depleted low pressure flash chamber discharge is combined with the condensate from the recuperator.

7. The system according to claim 6, further comprising a condensate pump for supplying the condensate to the heat exchanger means so as to ensure that the condensate will remain in a liquid phase.

8. The system according to claim 2, further comprising a first control valve in communication with a fluid line extending from the high pressure flash chamber to the high pressure turbine module, a second control valve in communication with a fluid line extending from the low pressure flash chamber and the low pressure turbine module,

9. The system according to claim 8 further comprising a third control valve in communication with a fluid line extending from the cycle pump to the direct contact recuperator.

10. The system according to claim 8, further comprising a first safety valve in communication with a fluid line extending from the heat exchanger means and the high pressure flash chamber, and a second safety valve in communication with a fluid line upstream to the heat exchanger means.

11. The system according to claim 10, further comprising a controller for controlling operation of the cycle pump, first control valve, second control valve, first safety valve and second safety valve in accordance with sensed operating conditions.

12. The system according to claim 9 further comprising a controller for controlling operation of the third control valve.

13. The system according to claim 7, further comprising a controller for controlling operation of the cycle pump, and condensate pump in accordance with sensed operating conditions.

14. The system according to claim 4, wherein the high pressure and low pressure turbine modules are separate turbine modules coupled to a common generator.

15. The system according to claim 4, wherein the high pressure and low pressure turbine modules are first and second stages, respectively, of a common turbine coupled to a generator.

16. A waste heat recovery system, comprising a closed fluid circuit through which an organic motive fluid flows, heat exchanger means for transferring heat from waste heat gases to said motive fluid, means for flashing the motive fluid which exits said heat exchanger means into a high pressure flashed vapor portion, means for flashing liquid non-flashed motive fluid producing a low pressure flashed vapor portion, a turbine for producing power having a high pressure stage which receives said high pressure flashed vapor portion, and a low pressure stage which receives a combined flow of motive fluid vapor comprising said low pressure flashed vapor portion and discharge vapor from said high pressure stage whereby additional power is produced by said turbine.