# US 9,518,480 B2 · Exhaust heat recovery device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,480 B2 - Document ID: US9518480B2 - Status: Granted - Kind: B2 - Application number: 14/400,295 - Filed: 2013-05-02 - Published: 2015-04-23 - Granted: 2016-12-13 - Earliest claimed: 2012-05-09 - Assignees: Sanden Holdings Corporation - Applicants: Sanden Corporation - Inventors: Tomonori Haraguchi; Hirofumi Wada - Web page: https://patentgrep.com/patent/US9518480B2 ## CPC - F01K 13/02: Controlling, e.g. stopping or starting - F01K 7/30: the turbines using exhaust steam only - F01K 23/065: {the combustion taking place in an internal combustion piston engine, e.g. a diesel engine} - F01K 23/10: with exhaust fluid of one cycle heating the fluid in another cycle (F01K17/025 takes precedence) - F01K 27/02: Plants modified to use their waste heat, other than that of exhaust, e.g. engine-friction heat - F02G 5/00: Profiting from waste heat of combustion engines, not otherwise provided for - F02G 2260/00: Recuperating heat from exhaust gases of combustion engines and heat from cooling circuits - Y02T 10/12: Improving ICE efficiencies - F01K: STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES (gas-turbine or jet-propulsion plants F02; nuclear power plants, engine arrangements therein G21D) - F02G: HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINE PLANTS (steam engine plants, special vapour plants, plants operating on either hot gas or combustion-product gases together with other fluid F01K; gas-turbine plants F02C; jet-propulsion plants F02K); USE OF WASTE HEAT OF COMBUSTION ENGINES; NOT OTHERWISE PROVIDED FOR - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An exhaust heat recovery device 1, with a Rankine cycle for recovering and using exhaust heat of an engine 10 includes: a Rankine cycle 2 including a heater 22, an expander 23, a condenser 24, and a pump 25; a bypass flow passage 26 allowing the refrigerant to circulate while bypassing the expander 23; a bypass valve 27 opening and closing the bypass flow passage 26; and a control unit 4. When starting up the Rankine cycle 2, the control unit 4 executes start-up control of the Rankine cycle 2 in which the pump 25 is actuated with the bypass valve 27 open and then the bypass valve 27 is closed. Furthermore, the control unit 4 repeatedly executes the start-up control when the pressure difference between the high-pressure side and the low-pressure side of the Rankine cycle 2 after closing the bypass valve 27 does not reach the start-up completion determination value within a predetermined time. ## Claims ### Claim 1 An exhaust heat recovery device comprising: a Rankine cycle in which a heater configured to heat and vaporize refrigerant by exhaust heat of an external heat source, an expander configured to generate power by expanding the refrigerant passed through the heater, a condenser configured to condense the refrigerant passed through the expander, and a pump configured to send the refrigerant passed through the condenser to the heater are disposed in a circulation passage of the refrigerant; a bypass flow passage that allows the refrigerant to circulate while bypassing the expander; a bypass valve that opens and closes the bypass flow passage; a pressure difference determining unit that determines a pressure difference between a high-pressure side and a low-pressure side of the Rankine cycle; and a control unit that executes start-up control of the Rankine cycle, the start-up control actuating the pump with the bypass valve open and then closing the bypass valve, wherein the control unit repeatedly executes the start-up control when the pressure difference after closing the bypass valve does not reach a start-up completion determination value of the Rankine cycle within a predetermined time, and wherein the control unit changes a valve-closing condition of the bypass valve each time the start-up control is repeated. ### Claim 2 (depends on 1) The exhaust heat recovery device according to claim 1, wherein the expander and the pump in the Rankine cycle are integrally connected to each other. ### Claim 3 An exhaust heat recovery device comprising: a Rankine cycle in which a heater configured to heat and vaporize refrigerant by exhaust heat of an external heat source, an expander configured to generate power by expanding the refrigerant passed through the heater, a condenser configured to condense the refrigerant passed through the expander, and a pump configured to send the refrigerant passed through the condenser to the heater are disposed in a circulation passage of the refrigerant; a bypass flow passage that allows the refrigerant to circulate while bypassing the expander; a bypass valve that opens and closes the bypass flow passage; a pressure difference determining unit that determines a pressure difference between a high-pressure side and a low-pressure side of the Rankine cycle; and a control unit that executes start-up control of the Rankine cycle, the start-up control actuating the pump with the bypass valve open and then closing the bypass valve, wherein the control unit repeatedly executes the start-up control when the pressure difference after closing the bypass valve does not reach a start-up completion determination value of the Rankine cycle within a predetermined time, and wherein the control unit executes, as the start-up control, control to actuate the pump with the bypass valve open, and then to close the bypass valve when the pressure difference becomes a valve-closing determination value or more, the valve-closing determination value being less than the start-up completion determination value. ### Claim 4 (depends on 3) The exhaust heat recovery device according to claim 3, wherein the expander and the pump in the Rankine cycle are integrally connected to each other. ### Claim 5 (depends on 3) The exhaust heat recovery device according to claim 3, wherein, when the repetition of the start-up control occurs, the control unit performs the increase correction of the valve-closing determination value in the start-up control at the time of the next start-up of the Rankine cycle, and then, when the repetition of the start-up control does not occur, the control unit reduces the valve-closing determination value subjected to the increase correction, for each start-up of the Rankine cycle. ### Claim 6 (depends on 5) The exhaust heat recovery device according to claim 5, wherein, in a case in which the start-up control is executed with the reduced valve-closing determination value, which has been subjected to the increase correction, when the pressure difference after closing the bypass valve does not reach the start-up completion determination value within the predetermined time, the control unit executes the start-up control again using the valve-closing determination value, which was used in the start-up control at the time of the previous start-up of the Rankine cycle. ### Claim 7 (depends on 3) The exhaust heat recovery device according to claim 3, wherein the control unit increases the valve-closing determination value each time the start-up control is repeated. ### Claim 8 (depends on 7) The exhaust heat recovery device according to claim 7, wherein the control unit increases an amount of increase of the valve-closing determination value each time the start-up control is repeated. ### Claim 9 (depends on 7) The exhaust heat recovery device according to claim 7, wherein the control unit stores the valve-closing determination value when the pressure difference after closing the bypass valve reaches the start-up completion determination value within the predetermined time, and sets the stored valve-closing determination value as an initial value of the valve-closing determination value in the start-up control at the time of the next start-up of the Rankine cycle. ### Claim 10 An exhaust heat recovery device comprising: a Rankine cycle in which a heater configured to heat and vaporize refrigerant by exhaust heat of an external heat source, an expander configured to generate power by expanding the refrigerant passed through the heater, a condenser configured to condense the refrigerant passed through the expander, and a pump configured to send the refrigerant passed through the condenser to the heater are disposed in a circulation passage of the refrigerant; a bypass flow passage that allows the refrigerant to circulate while bypassing the expander; a bypass valve that opens and closes the bypass flow passage; a pressure difference determining unit that determines a pressure difference between a high-pressure side and a low-pressure side of the Rankine cycle; and a control unit that, when starting up the Rankine cycle, executes control to actuate the pump with the bypass valve open, and then to close the bypass valve when the pressure difference becomes a predetermined value, wherein the control unit executes control to open the bypass valve when the pressure difference does not reach a start-up completion determination value greater than a first predetermined value within a predetermined time after closing the bypass valve when the pressure difference becomes the first predetermined value, and then to close the bypass valve when the pressure difference becomes a second predetermined value greater than the first predetermined value and less than the start-up completion determination value. ### Claim 11 (depends on 10) The exhaust heat recovery device according to claim 10, wherein the expander and the pump in the Rankine cycle are integrally connected to each other.