Rankine cycle apparatus and combined heat and power system

Patent metadata

Field	Value
Publication number	US-9638066-B2
Application number	US-201514792272-A
Country	US
Kind code	B2
Filing date	Jul 6, 2015
Priority date	Jan 10, 2013
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A Rankine cycle apparatus includes a pump, an evaporator, an expander, and a condenser. The evaporator has a plurality of heat transfer tubes arranged in rows in a flow direction of a high-temperature fluid to be heat-exchanged with a working fluid. The heat transfer tube located in a most upstream row in the flow direction of the high-temperature fluid is defined as a most upstream heat transfer tube. For example, the most upstream heat transfer tube forms an inlet of the evaporator so that the working fluid flows into the evaporator through the inlet and first passes through the most upstream heat transfer tube.

First claim

What is claimed is:

1. A Rankine cycle apparatus comprising:
a pump that pressurizes a working fluid;
an evaporator that heats the working fluid discharged from the pump;
an expander that expands the working fluid heated in the evaporator; and
a condenser that cools the working fluid discharged from the expander, wherein
the evaporator comprises a plurality of heat transfer tubes arranged in rows in a flow direction of a high-temperature fluid to be heat-exchanged with the working fluid,
when the heat transfer tube located in a most upstream row in the flow direction of the high-temperature fluid is defined as a most upstream heat transfer tube, the following requirement (A), or (B) is satisfied:
(A) the rows comprise a first section and a second section, the first section including the most upstream heat transfer tube, and the second section including the heat transfer tubes other than the most upstream heat transfer tube so that the second section accepts the working fluid having passed through the first section and allows the working fluid to exchange heat with the high-temperature fluid in a counter-flow manner; and
(B) the rows comprise a first section and a second section, the first section being composed of rows adjacent to each other and including the most upstream heat transfer tube in one of the rows and the heat transfer tube forming an inlet of the evaporator in a row other than the row of the most upstream heat transfer tube, and the second section being located downstream of the first section in the flow direction of the high-temperature fluid and accepting the working fluid having passed through the first section,
the working fluid has a thermal decomposition temperature lower than a temperature of the high-temperature fluid flowing on an outer peripheral surface of the most upstream heat transfer tube and is in a liquid phase or in a gas-liquid two phase when flowing in the most upstream heat transfer tube
the evaporator is a fin tube heat exchanger comprising a fin and further comprises a heat insulating structure that prevents heat transfer between the first section and the second section,
the first section and the second section share the fin, and
the heat insulating structure comprises a through hole formed in the fin at a boundary between the first section and the second section.

2. The Rankine cycle apparatus according to claim 1 , wherein
the requirement (B) is satisfied, and
at least a portion of the first section is configured to allow the working fluid and the high-temperature fluid to exchange heat with each other in a counter-flow manner.

3. The Rankine cycle apparatus according to claim 2 , wherein the second section is composed of rows adjacent to each other and is configured to allow the working fluid and the high-temperature fluid to exchange heat with each other in a parallel-flow manner in the heat transfer tubes located in at least two of the adjacent rows.

4. The Rankine cycle apparatus according to claim 2 , wherein the second section is composed of rows adjacent to each other and is configured to allow the working fluid and the high-temperature fluid to exchange heat with each other in a counter-flow manner in the heat transfer tubes located in at least two of the adjacent rows.

5. The Rankine cycle apparatus according to claim 1 , wherein the requirement (A) is satisfied.

6. The Rankine cycle apparatus according to claim 5 , wherein the most upstream heat transfer tube forms an inlet of the evaporator so that the working fluid flows into the evaporator through the inlet and first passes through the most upstream heat transfer tube.

7. The Rankine cycle apparatus according to claim 1 , wherein a member constituting the first section is spaced from a member constituting the second section.

8. The Rankine cycle apparatus according to claim 1 , wherein
the first section includes nothing but the heat transfer tube or the heat transfer tubes, and
the second section has a structure of a fin tube heat exchanger.

9. The Rankine cycle apparatus according to claim 1 , wherein the number of rows in the second section is larger than the number of rows in the first section.

10. The Rankine cycle apparatus according to claim 1 , wherein an outer diameter of the heat transfer tube included in the first section is larger than an outer diameter of the heat transfer tube included in the second section.

11. The Rankine cycle apparatus according to claim 1 , wherein the most upstream heat transfer tube is an internally smooth tube.

12. The Rankine cycle apparatus according to claim 1 , wherein
the evaporator is a fin tube heat exchanger comprising a fin, and
the fin is a flat fin without a cut-and-raised portion.

13. The Rankine cycle apparatus according to claim 1 , wherein the most upstream heat transfer tube is offset in the flow direction of the high-temperature fluid.

14. A combined heat and power system comprising:
the Rankin cycle apparatus according to claim 1 ; and
a heat medium circuit in which a heat medium flows, the heat medium serving as a low-temperature heat source for cooling the working fluid in the condenser of the Rankine cycle apparatus.

15. The Rankine cycle apparatus according to claim 1 , wherein
the first section includes only the most upstream heat transfer tube,
the most upstream heat transfer tube is an internally smooth tube, and
each of the heat transfer tubes in the second section is an internally grooved tube.

16. An evaporator for use in a Rankine cycle, comprising a plurality of heat transfer tubes arranged in rows in a flow direction of a high-temperature fluid to be heat-exchanged with a working fluid in the Rankine cycle, wherein
when the heat transfer tube located in a most upstream row in the flow direction of the high-temperature fluid is defined as a most upstream heat transfer tube, the following requirement (A), or (B) is satisfied:
(A) the rows comprise a first section and a second section, the first section including the most upstream heat transfer tube, and the second section including the heat transfer tubes other than the most upstream heat transfer tube so that the second section accepts the working fluid having passed through the first section and allows the working fluid to exchange heat with the high-temperature fluid in a counter-flow manner; and
(B) the rows comprise a first section and a second section, the first section being composed of rows adjacent to each other and including the most upstream heat transfer tube in one of the rows and the heat transfer tube forming an inlet of the evaporator in a row other than the row of the most upstream heat transfer tube, and the second section being located downstream of the first section in the flow direction of the high-temperature fluid and accepting the working fluid having passed through the first section,
the working fluid has a thermal decomposition temperature lower than a temperature of the high-temperature fluid flowing on an outer peripheral surface of the most upstream heat transfer tube and is in a liquid phase or in a gas-liquid two phase when flowing in the most upstream heat transfer tube
the evaporator is a fin tube heat exchanger comprising a fin and further comprises a heat insulating structure that prevents heat transfer between the first section and the second section,
the first section and the second section share the fin, and
the heat insulating structure comprises a through hole formed in the fin at a boundary between the first section and the second section.

17. The evaporator for use in a Rankine cycle

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Honma Masaya
• Okaichi Atsuo
• Kido Osao
• Hikichi Takumi
• Wada Masanobu
• Kosuda Osamu

Classifications

• F01K17/02 Primary

  for heating purposes, e.g. industrial, domestic (F01K17/06 takes precedence; domestic- or space-heating systems, e.g. central-heating systems, in general F24D1/00, F24D3/00, F24D9/00) · CPC title

• F28D7/0075

  with particular circuits for the same heat exchange medium, e.g. with the same heat exchange medium flowing through sections having different heat exchange capacities or for heating or cooling the same heat exchange medium at different temperatures · CPC title

• F22B1/1869

  Hot gas water tube boilers not provided for in F22B1/1807 - F22B1/1861 · CPC title

• F01K7/16

  the engines being only of turbine type (the engines using steam of critical or overcritical pressure F01K7/32; the engines being of extraction or non-condensing type F01K7/34) · CPC title

• Y02E20/14

  Combined heat and power generation [CHP] · CPC title