Exhaust-heat recovery apparatus

Patent metadata

Field	Value
Publication number	US-10107167-B2
Application number	US-201214403645-A
Country	US
Kind code	B2
Filing date	May 31, 2012
Priority date	May 31, 2012
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

An exhaust-heat recovery apparatus includes: a circulation passage, through which a heat carrier circulates, that has a heat recovery unit evaporating the heat carrier and a condenser condensing the evaporated heat carrier; a heat carrier controller that supplies the heat carrier in a liquid phase to the circulation passage; and a determination unit, in which the heat carrier controller supplies or recovers the heat carrier when a changing rate of an internal pressure in the circulation passage or a changing rate of a temperature of the heat carrier in the circulation passage is within a predetermined range, determines a type of abnormality based on the changing rate of the internal pressure in the circulation passage or the changing rate of the temperature of the heat carrier in the circulation passage after the supplying or the recovering of the heat carrier.

First claim

The invention claimed is:

1. An exhaust-heat recovery apparatus comprising:
a heat carrier passage, through which a heat carrier circulates, that has an evaporation unit evaporating the heat carrier and a condenser condensing the evaporated heat carrier, and the heat carrier is depressurized below atmospheric pressure in the heat carrier passage so that an internal pressure is a negative pressure lower than the atmospheric pressure in the heat carrier passage, and after circulating the heat carrier in the heat carrier passage and evaporating the heat carrier by the evaporation unit, the internal pressure becomes higher than the negative pressure as time goes on;
a heat carrier controller that changes an amount of the heat carrier in the heat carrier passage and supplies the heat carrier from a tank or recovers the heat carrier to the tank when the internal pressure is lower than the atmospheric pressure and a changing rate of the internal pressure in the heat carrier passage or a changing rate of a temperature of the heat carrier in the heat carrier passage is within a predetermined range; and
a determination unit that determines whether the heat carrier passage is abnormal based on the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier from the tank or the recovering of the heat carrier from the tank, wherein
the heat carrier is evaporated in the evaporating unit by a thermal exchange between an exhaust gas of an engine and the heat carrier and the evaporated heat carrier is condensed in the condenser by the thermal exchange between the evaporated heat carrier and the exhaust gas of the engine; and
the heat carrier controller includes a reserve tank to store heat carrier; and wherein the reserve tank includes an outlet valve to change the amount of the heat carrier in the heat carrier passage.

2. The exhaust-heat recovery apparatus as claimed in claim 1 , wherein:
the heat carrier controller supplies the heat carrier in the liquid phase into the heat carrier passage either when the internal pressure is equal to a pressure applied to the heat carrier in the liquid phase in the reservoir or less and the changing rate of the internal pressure is within the predetermined range or when the temperature is equal to a boiling point of the heat carrier or less and the changing rate of the temperature is within the predetermined value; and
the determination unit determines whether the heat carrier passage is abnormal based on the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier.

3. The exhaust-heat recovery apparatus as claimed in claim 2 , wherein:
the determination unit determines that the heat carrier passage is normal when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is less than a first value; and
the determination unit determines that the heat carrier passage is abnormal when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is equal to or more than the first value.

4. The exhaust-heat recovery apparatus as claimed in claim 3 , wherein:
the determination unit determines that the heat carrier does not exist in the heat carrier passage when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is equal to or more than a second value that is larger than the first value; and
the determination unit determines that the heat carrier passage lacks of the heat carrier when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is less than the second value and is equal to or more than the first value.

5. The exhaust-heat recovery apparatus as claimed in claim 2 , wherein:
the determination unit determines that the heat carrier passage is abnormal when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is equal to or more than a first value;
the determination unit determines that the heat carrier passage is normal when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is less than the first value and is equal to or more than a third value that is smaller than the first value; and
the determination unit determines that the heat carrier passage is closed when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is less than the third value.

6. The exhaust-heat recovery apparatus as claimed in claim 2 , wherein:
the determination unit determines that the heat carrier passage is abnormal when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is equal to or more than a first value;
the determination unit determines that the heat carrier passage is normal when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is less than the first value and is equal to or more than a third value that is smaller than the first value;
the determination unit determines that the heat carrier passage is normal when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is less than a fourth value that is smaller than the third value; and
the determination unit determines that the heat carrier passage is closed when the changing rate of the internal pressure or the changing rate of the temperature after the supplying of the heat carrier is less than the third value and is equal to or more than the fourth value.

7. The exhaust-heat recovery apparatus as claimed in claim 1 , wherein:
the heat carrier controller recovers the heat carrier from the heat carrier passage either when the internal pressure is larger than a pressure applied to the heat carrier in the liquid phase in the reservoir and the changing rate of the internal pressure is within a predetermined range or when the temperature is higher than a boiling point of the heat carrier and the changing rate of the temperature is within a predetermined range;
the determination unit determines that the heat carrier passage is normal when the internal pressure or the temperature is reduced after the recovering of the heat carrier; and
the determination unit determines that the heat carrier passage is closed or an amount of the heat carrier is excessive when the internal pressure or the temperature is not reduced after the recovering of the heat carrier.

Assignees

• Hotta Takashi
• Yamada Kenichi
• Toyota Motor Co Ltd

Inventors

• Hotta Takashi
• Yamada Kenichi

Classifications

• F01P2007/146

  using valves · CPC title

• Y02T10/166

  Cross-Sectional Technologies · mapped topic

• F01P7/16

  by thermostatic control · CPC title

• F02G5/02

  Profiting from waste heat of exhaust gases · CPC title

• F01N13/009

  having two or more separate purifying devices arranged in series · CPC title