Waste heat recovery device and waste heat recovery method

Patent metadata

Field	Value
Publication number	US-10184359-B2
Application number	US-201514662701-A
Country	US
Kind code	B2
Filing date	Mar 19, 2015
Priority date	Apr 4, 2014
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A waste heat recovery device including: a heater which evaporates an working medium by exchanging heat between supercharging air supplied to an engine and the working medium; a heat exchanger which heats the working medium by exchanging heat between the working medium which has flowed out from the heater and a heating medium; and an expander into which the working medium which has flowed out from the heat exchanger flows; a motive power recovery device; a condenser which condenses the working medium; and a pump which sends the working medium to a heater.

First claim

The invention claimed is:

1. A waste heat recovery device, comprising:
a heater which evaporates a working medium by exchanging heat between supercharging air supplied to an engine and the working medium;
a heat exchanger which heats the working medium by exchanging heat between the working medium which has flowed out from the heater and a heating medium;
an expander which expands the working medium which has flowed out from the heat exchanger;
a motive power recovery device having a rotary shaft which is connected to the expander;
a condenser which condenses the working medium which has flowed out from the expander;
a pump which sends the working medium which has flowed out from the condenser to the heater; and
a controller which increases and reduces the number of revolutions of the pump in accordance with an increase and decrease in a differential pressure between a pressure of the supercharging air before flowing into the heater and the pressure of the supercharging air after having flowed out from the heater, such that the number of revolutions of the pump invariably increases or decreases in the same direction as an increase or decrease in said differential pressure.

2. The waste heat recovery device according to claim 1 , further comprising:
a heating medium supply pipe which supplies the heating medium to the heat exchanger; and
an adjustment valve which is provided in the heating medium supply pipe, the degree of opening thereof being adjustable, wherein
the controller adjusts the degree of opening of the adjustment valve such that the degree of superheating of the working medium which has flowed out from the heat exchanger comes within a set range.

3. The waste heat recovery device according to claim 2 , wherein the controller closes the adjustment valve when the temperature of the supercharging air flowing into the heater exceeds a reference temperature.

4. The waste heat recovery device according to claim 2 , wherein
the engine is a ship engine in a ship; and
the heating medium supply pipe is configured so as to be able to supply excess steam generated in the ship to the heat exchanger, as the heating medium.

5. The waste heat recovery device according to claim 3 , wherein
the engine is a ship engine in a ship; and
the heating medium supply pipe is configured so as to be able to supply excess steam generated in the ship to the heat exchanger, as the heating medium.

6. A waste heat recovery method for recovering waste heat from supercharging air supplied to an engine, the method comprising:
an evaporating step for evaporating a working medium by a heater, by supplying the supercharging air to the heater;
a heating step for heating the working medium by exchanging heat between the working medium which has flowed out from the heater and a heating medium by use of a heat exchanger;
a motive power recovery step for recovering motive power from the working medium, by expanding the working medium which has flowed out from the heat exchanger by use of an expander;
a condensing step for condensing the working medium which has flowed out from the expander by use of a condenser; and
a pump driving step for sending, by use of a pump, the working medium which has flowed out from the condenser to the heater, wherein
in the pump driving step, the number of revolutions of the pump is increased and reduced in accordance with an increase and decrease in a differential pressure between a pressure of the supercharging air before flowing into the heater and the pressure of the supercharging air after having flowed out from the heater, such that the number of revolutions of the pump invariably increases or decreases in the same direction as an increase or decrease in said differential pressure.

7. The waste heat recovery method according to claim 6 , wherein, in the heating step, the amount of the heating medium flowing into the heat exchanger is adjusted such that the degree of superheating of the working medium which has flowed out from the heat exchanger comes within a set range.

8. The waste heat recovery method according to claim 7 , wherein, in the heating step, the inflow of the heating medium to the heat exchanger is halted when the temperature of the supercharging air flowing into the heater exceeds a reference temperature.

9. The waste heat recovery method according to claim 6 , wherein
a ship engine is used as the engine; and
excess steam generated in a ship is used as a heating medium to be supplied to the heat exchanger.

10. The waste heat recovery method according to claim 7 , wherein
a ship engine in a ship is used as the engine; and
excess steam generated in the ship is used as a heating medium to be supplied to the heat exchanger.

11. The waste heat recovery method according to claim 8 , wherein
a ship engine in a ship is used as the engine; and
excess steam generated in the ship is used as a heating medium to be supplied to the heat exchanger.

12. A power system comprising:
an engine;
a supercharger comprising a turbine configured to be driven by exhaust gas from the engine, and a compressor connected to the turbine and configured to supercharge air supplied to the engine;
a heater configured to exchange heat in the heater between the supercharging air supplied to the engine and a working medium, to evaporate the working medium;
a heat exchanger configured to exchange heat between the working medium which has flowed out from the heater and a heating medium, to further heat the working medium;
an expander configured to expand the working medium which has flowed out from the heat exchanger;
a motive power recovery device having a rotary shaft which is connected to the expander;
a condenser configured to condense the working medium which has flowed out from the expander; and
a pump configured to send the working medium which has flowed out from the condenser to the heater; and
a controller which increases and reduces the number of revolutions of the pump in accordance with an increase and decrease in a differential pressure between a pressure of the supercharging air before flowing into the heater and the pressure of the supercharging air after having flowed out from the heater, such that the number of revolutions of the pump invariably increases or decreases in the same direction as an increase or decrease in said differential pressure.

13. The power system according to claim 12 , wherein
the engine is a ship engine in a ship; and
the heating medium is excess steam generated in the ship.

Assignees

• Kobe Steel Ltd
• Miura Kogyo Kk
• Asahi Shipping Co Ltd
• Tsuneishi Shipbuilding Co Ltd

Inventors

• Fujisawa Ryo
• Takahashi Kazuo
• Tanaka Yuji
• Adachi Shigeto
• Narukawa Yutaka

Classifications

• F02G5/00

  Profiting from waste heat of combustion engines, not otherwise provided for · CPC title

• F01K23/18

  characterised by adaptation for specific use · CPC title

• Y02T10/144

  Cross-Sectional Technologies · mapped topic

• F02B29/0443

  Layout of the coolant or refrigerant circuit · CPC title

• Y02T10/166

  Cross-Sectional Technologies · mapped topic