Device for Utilizing Waste Heat of Engine
First Claim
1. A device for utilizing waste heat from an engine, comprising:
- a Rankine cycle device provided in a circulation passage of a refrigerant with an evaporator that evaporates the refrigerant by heating the refrigerant by the waste heat of the engine, an expander that expands the refrigerant which has passed through the evaporator to thereby generate power, a condenser that condenses the refrigerant which has passed through the expander, and a pump that delivers the refrigerant which has passed through the condenser to the evaporator, and provided with an expander bypass passage that allows the refrigerant to circulate while bypassing the expander, and a bypass valve that opens and closes the expander bypass passage;
a transmission mechanism that transmits an output of the Rankine cycle device to the engine; and
a calculation processing unit that calculates the output of the Rankine cycle device and outputs the calculated output of the Rankine cycle device to an engine control unit that performs output control of the engine,wherein the calculation processing unit has;
a first torque estimation portion that estimates a torque of the expander in a state in which the bypass valve is open, based on a refrigerant pressure on the high pressure side of the Rankine cycle device and a refrigerant pressure on the low pressure side thereof; and
a second torque estimation portion that estimates a torque of the expander in a state in which the bypass valve is closed, based on the refrigerant pressure on the high pressure side of the Rankine cycle device and the refrigerant pressure on the low pressure side thereof, andwherein the output of the Rankine cycle device is calculated based on the torque estimated value by the first torque estimation portion and the torque estimated value by the second torque estimation portion.
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Accused Products
Abstract
Device for utilizing waste heat from an engine provided with a Rankine cycle device having an expander bypass passage opened and closed by a bypass valve, and transmits the output of the Rankine cycle device to the engine, estimates the output of the Rankine cycle device accurately regardless of an open or closed state of the bypass valve and thereby enables appropriate output control of the engine. An output calculation part 42 includes a torque estimation portion 421 that estimates the torque of an expander 23 with first and second torque estimation equations corresponding, respectively, to states in which a bypass valve 27 is open or closed. The output calculation part 42 calculates an output of a Rankine cycle device 2A, based on the estimated torque value. The calculated output of the Rankine cycle device 2A is output to an engine control unit 12.
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Citations
8 Claims
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1. A device for utilizing waste heat from an engine, comprising:
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a Rankine cycle device provided in a circulation passage of a refrigerant with an evaporator that evaporates the refrigerant by heating the refrigerant by the waste heat of the engine, an expander that expands the refrigerant which has passed through the evaporator to thereby generate power, a condenser that condenses the refrigerant which has passed through the expander, and a pump that delivers the refrigerant which has passed through the condenser to the evaporator, and provided with an expander bypass passage that allows the refrigerant to circulate while bypassing the expander, and a bypass valve that opens and closes the expander bypass passage; a transmission mechanism that transmits an output of the Rankine cycle device to the engine; and a calculation processing unit that calculates the output of the Rankine cycle device and outputs the calculated output of the Rankine cycle device to an engine control unit that performs output control of the engine, wherein the calculation processing unit has; a first torque estimation portion that estimates a torque of the expander in a state in which the bypass valve is open, based on a refrigerant pressure on the high pressure side of the Rankine cycle device and a refrigerant pressure on the low pressure side thereof; and a second torque estimation portion that estimates a torque of the expander in a state in which the bypass valve is closed, based on the refrigerant pressure on the high pressure side of the Rankine cycle device and the refrigerant pressure on the low pressure side thereof, and wherein the output of the Rankine cycle device is calculated based on the torque estimated value by the first torque estimation portion and the torque estimated value by the second torque estimation portion. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A device for utilizing waste heat from an engine, comprising:
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a Rankine cycle device provided in a circulation passage of a refrigerant with an evaporator that evaporates the refrigerant by heating the refrigerant by the waste heat of the engine, an expander that expands the refrigerant which has passed through the evaporator to thereby generate power, a condenser that condenses the refrigerant which has passed through the expander, and a pump that delivers the refrigerant which has passed through the condenser to the evaporator, and provided with an expander bypass passage that allows the refrigerant to circulate while bypassing the expander, and a bypass valve that opens and closes the expander bypass passage; a transmission mechanism that transmits an output of the Rankine cycle device to the engine; and a calculation processing unit that calculates the output of the Rankine cycle device, based on a torque of the expander and outputs the calculated output of the Rankine cycle device to an engine control unit that performs output control of the engine, wherein the calculation processing unit has a torque estimation portion that estimates a torque of the expander, based on a refrigerant pressure on the high pressure side of the Rankine cycle device and a refrigerant pressure on the low pressure side thereof, and limits the estimated torque of the expander so that the estimated torque of the expander is made not to fall below a negative predetermined value.
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Specification