Recuperated Rankine boost cycle

• US 9,359,919 B1
• Filed: 03/23/2015
• Issued: 06/07/2016
• Est. Priority Date: 03/23/2015
• Status: Active Grant

• Current Assignee: Just In Time Energy Company
• Original Assignee: James E. Berry
• Inventors: Berry, James E.
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): Mian, Shafiq
• Application Number:
  US14/665,534
• Time in Patent Office: 442 Days
• US Class Current: 1/1
• CPC Class Codes: F01K 25/08 using special vapours
• CPC Class Codes: F01K 25/103 Carbon dioxide F01K25/065 takes precedence
• CPC Class Codes: F01K 25/106 Ammonia F01K25/065 takes precedence
• CPC Class Codes: F01K 9/00 Plants characterised by condensers arranged or modified to co-operate with the engines by condensers structurally combined with engines F01K11/00; steam condensers per se F28BF01K23/04 takes precedence

Abstract

An improvement to Rankine type heat recovery power cycles by adding heat source heat exchanger(s) in parallel with the existing recuperator(s) and in series with the existing heat source exchangers.

Claims

1. A thermodynamic system comprising:

a pump having a low-pressure input port connected to a high-pressure output port;

a first flow divider having an input port connected to first and second output ports, wherein (i) the input port of the first flow divider is connected to the high-pressure output port of the pump and (ii) the first flow divider divides a working fluid stream received at the input port of the first flow divider into working fluid streams at the first and second output ports of the first flow divider;

a first recuperator having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein the third port of the second recuperator is connected to the first output port of the first flow divider;

a bypass valve having an input port connected to an output port, wherein the input port of the bypass valve is connected to the second output port of the first flow divider; and

a first flow mixer having first and second input ports connected to an output port, wherein (i) the first input port of the first flow mixer is connected to the fourth port of the first recuperator, (ii) the second input port of the first flow mixer is connected to the output port of the bypass valve, and (iii) the first flow mixer combines working fluid streams received at the first and second input ports of the first flow mixer into a working fluid stream at the output port of the first flow mixer;

a second flow divider having an input port connected to first and second output ports, wherein (i) the input port of the second flow divider is connected to the output port of the first flow mixer and (ii) the second flow divider divides a working fluid stream received at the input port of the second flow divider into working fluid streams at the first and second output ports of the second flow divider;

a first heat exchanger having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein the third port of the first heat exchanger is connected to the first output port of the second flow divider;

a second recuperator having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein;

the third port of the second recuperator is connected to the second output port of the second flow divider; and

the second port of the second recuperator is connected to the first port of the first recuperator;

a second flow mixer having first and second input ports connected to an output port, wherein (i) the first input port of the second flow mixer is connected to the fourth port of the first heat exchanger, (ii) the second input port of the second flow mixer is connected to the fourth port of the second recuperator, and (iii) the second flow mixer combines working fluid streams received at the first and second input ports of the second flow mixer into a working fluid stream at the output port of the second flow mixer;

a second heat exchanger having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein;

the third port of the second heat exchanger is connected to the output port of the second flow mixer; and

the second port of the second heat exchanger is connected to the first port of the first heat exchanger;

an expansion device that converts fluid energy into mechanical energy, the expansion device having a high-pressure input port connected to a low-pressure output port, wherein;

the high-pressure input port of the expansion device is connected to the fourth port of the second heat exchanger; and

the low-pressure output port of the expansion device is connected to the first port of the second recuperator;

a condenser/cooler having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein (a) the first port of the condenser/cooler is connected to the second port of the first recuperator and (b) the second port of the condenser/cooler is connected to the low-pressure input port of the pump, wherein;

within the first heat exchanger, heat flows from a heat-source fluid stream received at the first port of the first heat exchanger to the working fluid stream received at the third port of the first heat exchanger;

within the second heat exchanger, heat flows from a heat-source fluid stream received at the first port of the second heat exchanger to the working fluid stream received at the third port of the second heat exchanger;

within the first recuperator, heat flows from a working fluid stream received at the first port of the first recuperator to a working fluid stream received at the third port of the first recuperator;

within the second recuperator, heat flows from a working fluid stream received at the first port of the second recuperator to a working fluid stream received at the third port of the second recuperator;

within the condenser/cooler, heat flows from a working fluid stream received at the first port of the condenser/cooler to a cooling fluid stream received at the third port of the condenser/cooler; and

within the thermodynamic system, the working fluid streams from the high-pressure output port of the pump to the high-pressure input port of the expansion device are all above the critical pressure of the working fluid.

2. The thermodynamic system of claim 1, wherein the working fluid streams from the low-pressure output port of the expansion device to the low-pressure input port of the pump are all below the critical pressure of the working fluid.

3. The thermodynamic system of claim 1, wherein the working fluid streams from the low-pressure output port of the expansion device to the low-pressure input port of the pump are all above the critical pressure of the working fluid.

4. The thermodynamic system of claim 2, wherein:

the working fluid stream received at the third port of the second heat exchanger is supercritical with both the temperature and pressure above the critical values of the working fluid; and

the working fluid stream output from the fourth port of the second heat exchanger is supercritical with a temperature greater than the temperature of the working fluid stream received at the third port.

5. The thermodynamic system of claim 3, wherein:

the working fluid stream received at the third port of the second heat exchanger is supercritical with both the temperature and pressure above the critical values of the working fluid; and

the working fluid stream output from the fourth port of the second heat exchanger is supercritical with a temperature greater than the temperature of the working fluid stream received at the third port.

6. A method for implementing a thermodynamic cycle using a thermodynamic system, the thermodynamic system comprising:

a pump having a low-pressure input port connected to a high-pressure output port;

a first flow divider having an input port connected to first and second output ports, wherein the input port of the first flow divider is connected to the high-pressure output port of the pump;

a first heat exchanger having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein the third port of the first heat exchanger is connected to the first output port of the first flow divider;

a first recuperator having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein the third port of the first recuperator is connected to the second output port of the first flow divider;

a first flow mixer having first and second input ports connected to an output port, wherein (i) the first input port of the first flow mixer is connected to the fourth port of the first heat exchanger and (ii) the second input port of the first flow mixer is connected to the fourth port of the first recuperator;

a second heat exchanger having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein the third port of the second heat exchanger is connected to the output port of the first flow mixer;

an expansion device that converts fluid energy into mechanical energy, the expansion device having a high-pressure input port connected to a low-pressure output port, wherein;

the high-pressure input port of the expansion device is connected to the fourth port of the second heat exchanger; and

the low-pressure output port of the expansion device is connected to the first port of the first recuperator; and

a condenser/cooler having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein (a) the first port of the condenser/cooler is connected to the second port of the first recuperator and (b) the second port of the condenser/cooler is connected to the low-pressure input port of the pump, wherein;

the second port of the second heat exchanger is connected to the first port of the first heat exchanger; and

the working fluid streams from the high-pressure output port of the pump to the high-pressure input port of the expansion device are all above the critical pressure of the working fluid, the method for implementing the thermodynamic cycle comprising;

(a) using the pump to increase pressure of the working fluid stream received at the low-pressure input port of the pump into the working fluid stream above the critical pressure at the high-pressure output port of the pump;

(b) using the first flow divider to divide the working fluid stream above the critical pressure received at the input port of the first flow divider into the working fluid streams above the critical pressure at the first and second output ports of the first flow divider;

(c) using the first heat exchanger to transfer heat from a heat-source fluid stream received at the first port of the first heat exchanger to the working fluid stream above the critical pressure received at the third port of the first heat exchanger;

(d) using the first recuperator to transfer heat from the working fluid stream received at the first port of the first recuperator to the working fluid stream above the critical pressure received at the third port of the first recuperator;

(e) using the first flow mixer to combine the working fluid streams above the critical pressure received at the first and second input ports of the first flow mixer into the working fluid stream above the critical pressure at the output port of the first flow mixer;

(f) using the second heat exchanger to transfer heat from a heat-source fluid stream received at the first port of the second heat exchanger to the working fluid stream above the critical pressure received at the third port of the second heat exchanger;

(g) using the expansion device to expand the working fluid stream above the critical pressure received at the high-pressure input port of the expansion device into the working fluid stream at the low-pressure output port of the expansion device; and

(h) using the condenser/cooler to transfer heat from the working fluid stream received at the first port of the condenser/cooler to a cooling fluid stream received at the third port of the condenser/cooler, and the method for implementing the thermodynamic cycle is configured to;

convert the working fluid stream from a liquid state into a supercritical fluid state between (i) the input port of the pump and (ii) the third port of the second heat exchanger.

7. The method of claim 6, wherein the working fluid streams from the low-pressure output port of the expansion device to the low-pressure input port of the pump are all below the critical pressure.

8. The method of claim 6, wherein:

the working fluid stream is received at the third port of the first heat exchanger in the liquid state and converted within the first heat exchanger into the working fluid stream output at the fourth port of the first heat exchanger in the supercritical fluid state; and

the working fluid stream is received at the third port of the first recuperator in liquid state and converted within the first recuperator into the working fluid stream output at the fourth port of the first recuperator in the supercritical fluid state.

9. The method of claim 6, wherein the working fluid streams from the low-pressure output port of the expansion device to the low-pressure input port of the pump are all above the critical pressure.

10. The method of claim 6, wherein the working fluid is a single-component working fluid.

11. The method of claim 6, wherein the working fluid is a multi-component working fluid.

12. The method of claim 6, wherein:

the thermodynamic system further comprises;

a second flow divider having an input port connected to first and second output ports, wherein the input port of the second flow divider is connected to the high-pressure output port of the pump;

a second recuperator having (i) a first port connected to a second port and (ii) a third port connected to a fourth port, wherein;

the first port of the second recuperator is connected to the second port of the first recuperator;

the second port of the second recuperator is connected to the first port of the condenser/cooler; and

the third port of the second recuperator is connected to the first output port of the second flow divider;

a bypass valve having an input port connected to an output port, wherein the input port of the bypass valve is connected to the second output port of the second flow divider; and

a second flow mixer having first and second input ports connected to an output port, wherein (i) the first input port of the second flow mixer is connected to the fourth port of the second recuperator, (ii) the second input port of the second flow mixer is connected to the output port of the bypass valve, and (iii) the output port of the second flow mixer is connected to the input port of the first flow divider; and

the method further comprises;

(i) using the second flow divider to divide the working fluid stream above the critical pressure received at the input port of the second flow divider into the working fluid streams above the critical pressure at the first and second output ports of the second flow divider;

(j) using the second recuperator to transfer heat from the working fluid stream received at the first port of the second recuperator to the working fluid stream above the critical pressure received at the third port of the second recuperator;

(k) using the bypass valve to regulate the amount of working fluid stream passing from the input port of the bypass valve to the output port of the bypass valve; and

(l) using the second flow mixer to combine the working fluid streams above the critical pressure received at the first and second input ports of the second flow mixer into the working fluid stream above the critical pressure at the output port of the second flow mixer.