JP2008240614A - Engine waste heat recovery system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine waste heat recovery system for further properly controlling a supply state of a cooling medium in response to an operation state of an engine. <P>SOLUTION: This engine waste heat recovery system 100 has a cooling water supply pump 146 and a cooling water injection part 150. The cooling water supply pump 146 is constituted for supplying cooling water to the cooling water injection part 150 in response to the operation state of the engine. The cooling water injection part 150 is constituted for injecting the liquid cooling water toward an engine block 110. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an engine waste heat recovery system configured to recover mechanical energy from engine waste heat.

  As this type of engine waste heat recovery system, for example, those described in JP-A-6-88523, JP-A-2000-73753, JP-A-2000-345835 and the like are known. These engine waste heat recovery systems generate steam from cooling water (cooling medium) by waste heat such as combustion heat and friction heat, and convert the expansion energy of this steam into mechanical energy, thereby converting energy from waste heat. It is comprised so that it can collect | recover.

  Specifically, this type of engine waste heat recovery system generally includes a cylinder block, a supply pump, an inflow path, an outflow path, a heater (superheater), an expander (turbine), a condenser, It is equipped with.

  The cylinder block is provided with a water jacket. The supply pump is configured to supply the cooling water to the water jacket via the inflow passage.

  The outflow passage communicates with the heater. This heater is configured to further heat (overheat) the steam by heat exchange between the relatively high temperature exhaust gas and the steam flowing out of the water jacket.

  The expander is configured to convert the expansion energy of superheated steam into mechanical energy.

  The condenser is configured to condense the vapor into a liquid by cooling the vapor that has lost its energy and has become low pressure.

  In the engine waste heat recovery system having such a configuration, the cooling water is supplied from the inflow path to the water jacket. Within the water jacket, steam is generated from the cooling water. The steam is further heated (overheated) by heat exchange with the exhaust gas by the heater.

Then, the heated (overheated) steam expands in the expander. Thereby, mechanical energy is recovered. Thereafter, the low-pressure vapor that has lost energy flows into the condenser and is condensed into a liquid. The cooling water that has become liquid by being condensed in the condenser in this manner is supplied again to the water jacket by the supply pump.
JP-A-6-88523 JP 2000-73753 A JP 2000-345835 A

  In this type of engine waste heat recovery system, the cooling medium includes (1) engine cooling to prevent overheating, and (2) mechanical energy recovery by absorption and expansion of waste heat (reduction of cooling loss and fuel consumption). Improvement).

  In this regard, the conventional engine waste heat recovery system of this type has room for improvement in the supply state of the cooling medium.

  The present invention provides an engine waste heat recovery system in which the supply state of the cooling medium can be more appropriately controlled in accordance with the operating state of the engine.

  The engine waste heat recovery system of the present invention includes an engine block, a cooling medium injection section, a steam outlet, a steam heater, an expander, a condenser, a cooling medium supply pump, It has.

  The engine block is formed with a cylinder, a combustion chamber, an exhaust passage, and a cooling medium jacket. The exhaust passage is provided so as to communicate with the combustion chamber. The cooling medium jacket is provided adjacent to the cylinder, the combustion chamber, and the exhaust passage.

  The cooling medium injection unit is configured to inject a liquid cooling medium toward an inner wall surface of the cooling medium jacket.

  The steam outlet path is connected to the cooling medium jacket. The steam lead-out path is configured to lead out the steam of the cooling medium vaporized after being injected by the cooling medium injection unit to the outside of the cooling medium jacket.

  The steam heater is interposed in the steam lead-out path. The steam heater is configured to heat the steam by heat exchange between the exhaust gas passing through the exhaust passage and the steam.

  The expander is interposed in the steam outlet path. The expander is configured to recover mechanical energy from the steam that has passed through the steam heater. As this expander, the structure provided with the turbine or the piston may be used, for example.

  The condenser is configured to condense the vapor that has passed through the expander. That is, the condenser is configured such that the vapor that has passed through the expander passes through the condenser, so that the liquid cooling medium is generated from the vapor.

  The cooling medium supply pump is configured to supply the liquid cooling medium condensed through the condenser to the cooling medium injection unit according to the operating state of the engine.

  In the engine waste heat recovery system of the present invention having such a configuration, the cooling medium supply pump supplies the liquid cooling medium to the cooling medium injection unit according to the operating state of the engine. Then, the liquid cooling medium is injected toward the inner wall surface of the cooling medium jacket by the cooling medium injection unit. Thereby, the engine block is cooled. Further, as the engine block is cooled, the cooling medium absorbs heat and steam of the cooling medium is generated.

  This steam is led out to the steam lead-out path and reaches the steam heater. In this steam heater, the steam is heated (overheated) by heat exchange between the exhaust gas passing through the exhaust passage and the steam.

  The heated steam expands in the expander. Thereby, mechanical energy is recovered from the steam. The steam passing through the expander reaches the condenser. In this condenser, the steam is condensed. That is, the cooling medium becomes a liquid in the condenser. The cooling medium that has become liquid can be supplied again to the cooling medium ejection unit.

  According to the engine waste heat recovery system of the present invention, the supply state of the liquid cooling medium to the cooling medium injection unit and the cooling medium jacket can be more appropriately controlled according to the operating state of the engine. . Therefore, energy recovery by heat absorption of the cooling medium and cooling of the engine block can be appropriately performed.

  The cooling medium injection unit may be configured to inject the cooling medium into a (fine) droplet shape and inject it toward the engine block.

  According to such a configuration, the occurrence of the film boiling phenomenon on the inner wall surface of the cooling medium jacket to which the cooling medium is injected can be reduced or suppressed. Therefore, the cooling efficiency of the engine block and the energy recovery efficiency from waste heat can both be made higher.

  The engine waste heat recovery system may further include a block temperature sensor. The block temperature sensor is configured to generate an output corresponding to the temperature of the engine block. In this case, the coolant supply pump supplies the liquid coolant to the coolant injection unit based on the output of the block temperature sensor when the temperature of the engine block is equal to or higher than a predetermined injection start temperature. It is comprised so that it may supply.

  In such a configuration, the block temperature sensor generates an output corresponding to the temperature of the engine block. The operation of the cooling medium pump is controlled according to this output. That is, when the temperature of the engine block becomes equal to or higher than a predetermined injection start temperature, the cooling medium pump is driven based on the output of the block temperature sensor. As a result, the liquid cooling medium is supplied to the cooling medium injection unit and is injected toward the inner wall surface of the cooling medium jacket.

  The cooling medium injection unit includes a plurality of nozzles provided corresponding to a plurality of positions in the engine block, and the cooling medium injection state at the plurality of nozzles according to the operating state of the engine You may be comprised so that it can change.

  In such a configuration, the injection state of the cooling medium in the plurality of nozzles is changed according to the operating state of the engine. Therefore, energy recovery by heat absorption of the cooling medium and cooling of the engine block can be performed more appropriately.

  The engine waste heat recovery system may further include a heat exchange unit. This heat exchanging section is between the cooling medium sent out toward the cooling medium injection section (for example, the liquid cooling medium condensed through the condenser) and the steam through the expander. It is comprised so that heat exchange may be performed.

  In this configuration, the liquid cooling medium delivered toward the cooling medium ejecting unit is heated by the steam that has passed through the expander. The heated cooling medium is supplied again to the cooling medium injection unit by the operation of the cooling medium supply pump. On the other hand, the steam that has passed through the expander is cooled by heat exchange with the cooling medium.

  According to this configuration, a part of the heat of the steam that has passed through the expander is re-taken into the cooling medium that is sent out toward the cooling medium injection unit without being discarded outside by the condenser. It is. Therefore, the cooling loss can be further reduced.

  In addition, according to this configuration, the engine block at the time of the injection of the cooling medium by the cooling medium injection unit is heated by heating the liquid cooling medium delivered toward the cooling medium injection unit The thermal shock to can be reduced.

  The engine waste heat recovery system may further include a steam temperature sensor, a steam pressure sensor, an abnormality determination unit, and an abnormality notification unit.

  Here, the steam temperature sensor is interposed in the steam lead-out path, and is configured to generate an output corresponding to the temperature of the steam. The steam pressure sensor is interposed in the steam lead-out path, and is configured to generate an output corresponding to the pressure of the steam. The abnormality determination unit is configured to determine whether or not an abnormality has occurred based on outputs of the steam temperature sensor and the vapor pressure sensor. The abnormality notifying unit is configured to notify the occurrence of an abnormality when the abnormality determining unit determines that an abnormality has occurred.

  In such a configuration, the steam temperature sensor generates an output corresponding to the steam temperature. The vapor pressure sensor generates an output corresponding to the vapor pressure. Based on these outputs, the abnormality determination unit determines whether an abnormality has occurred in the system. When the occurrence of an abnormality in the system is determined, the abnormality notification unit notifies the occurrence of the abnormality.

  The engine waste heat recovery system may further include an abnormal operation control unit. The abnormal-time operation control unit is configured to control the operation state of the engine to a predetermined abnormal-time operation mode when occurrence of an abnormality is determined by the abnormality determination unit.

  In such a configuration, when the occurrence of an abnormality in the system is determined by the abnormality determination unit, the operation state of the engine is controlled to a predetermined abnormality operation mode by the abnormality operation control unit.

  Hereinafter, embodiments of the present invention (embodiments that the applicant considers best at the time of filing of the present application) will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an engine waste heat recovery system 100 according to an embodiment of the present invention.

<Engine block configuration>
Referring to FIG. 1, an engine waste heat recovery system 100 includes an engine block 110 that constitutes a main body of an in-line multi-cylinder gasoline engine. The engine block 110 includes a cylinder block 120 and a cylinder head 130. The lower end surface of the cylinder head 130 is joined to the upper end surface of the cylinder block 120.

  The cylinder block 120 is formed with a cylinder 121 that is a substantially cylindrical through hole. The cylinder 121 is provided such that its upper end communicates with the combustion chamber CC. A piston 122 is accommodated in the cylinder 121 so as to be capable of reciprocating along the height direction (vertical direction in the drawing) of the cylinder 121.

  Further, the cylinder block 120 is formed with a lower jacket 123 that constitutes the cooling medium jacket of the present invention. The lower jacket 123 is provided so as to surround the cylinder 121. That is, the lower jacket 123 is provided adjacent to the cylinder 121. The lower jacket 123 is a substantially ring-shaped space in plan view, and is configured so that cooling water and steam can pass through the space.

  An intake port 131 and an exhaust port 132 are formed in the cylinder head 130. The intake port 131 and the exhaust port 132 are provided so as to communicate with the upper end portion of the cylinder 121 and the combustion chamber CC. The exhaust port 132 is connected to the exhaust passage 133. That is, the exhaust passage 133 is provided so as to communicate with the combustion chamber CC.

  In the present embodiment, two intake ports 131 are provided along the cylinder arrangement direction. The pair of intake ports 131 are formed substantially symmetrically across a plane passing through the axial center of the cylinder 121. Similarly, two exhaust ports 132 are provided along the cylinder arrangement direction.

  An upper jacket 134 constituting the cooling medium jacket of the present invention is formed inside the cylinder head 130.

  The upper jacket 134 is a space configured such that liquid cooling water and its vapor can pass through the upper jacket 134. The upper jacket 134 is provided adjacent to the intake port 131, the exhaust port 132, and the combustion chamber CC. That is, the upper jacket 134 is provided between the pair of intake ports 131, between the pair of exhaust ports 132, and between the intake port 131 and the exhaust port 132. Further, the upper jacket 134 is provided so as to communicate with the upper end portion of the lower jacket 123.

  A steam discharge port 135 is formed in the upper part of the cylinder head 130. Specifically, the steam outlet 135 is provided so as to extend upward from the uppermost portion of the upper jacket 134. The steam outlet 135 is connected to the uppermost part of the upper jacket 134. The steam discharge port 135 is configured to discharge the steam in the upper jacket 134 to the outside of the upper jacket 134.

<Configuration of waste heat recovery unit>
The engine waste heat recovery system 100 includes a waste heat recovery unit 140. The waste heat recovery unit 140 converts the steam discharged from the upper jacket 134 through the steam outlet 135 and the heat of the exhaust gas discharged to the exhaust passage 133 through the exhaust port 132 into mechanical energy for recovery. As described above, the following configuration is provided.

  The steam lead-out path 141 is connected to the upper jacket 134 via the steam discharge port 135. The steam lead-out path 141 is a path for steam discharged from the steam discharge port 135, and the steam of the cooling water generated in the lower jacket 123 and the upper jacket 134 is sent to the engine block 110 (lower jacket 123 and upper jacket 134). It is configured to lead out.

  A superheater 142 as a steam heater according to the present invention is interposed in the steam outlet path 141. The superheater 142 is connected to the exhaust passage 133. The superheater 142 is configured to heat the steam by heat exchange between the exhaust gas and the steam. That is, the superheater 142 is configured to generate superheated steam by heating the steam discharged from the steam discharge port 135 with the exhaust gas.

  A turbine 143 as an expander of the present invention is interposed on the downstream side of the steam outlet path 141 in the steam flow direction from the superheater 142. The turbine 143 is configured to recover mechanical energy from superheated steam generated via the superheater 142. In other words, the turbine 143 includes rotating blades, and the rotating blades are configured to rotate by the expansion of superheated steam introduced from the superheater 142.

  A condenser 144 as a condenser according to the present invention is interposed on the downstream side of the steam outlet path 141 in the steam flow direction from the turbine 143. The condenser 144 is configured to be able to condense by cooling the steam that has passed through the turbine 143 by heat exchange with the outside air. The capacitor 144 has a configuration similar to that of the radiator.

  A cooling water flow path 145 is connected to the capacitor 144. The cooling water passage 145 is a passage of cooling water condensed by the condenser 144 to become a liquid. The condenser 144 is connected to the start end thereof, and the cooling water supply pump 146 is connected to the end opposite to the start end. It is connected.

  The cooling water supply pump 146 as the cooling medium supply pump according to the present invention is an electric pump, and the liquid cooling water condensed through the condenser 144 is converted into a cooling water injection unit to be described later according to the operating state of the engine. 150 is provided.

  A branch passage 147 is provided so as to branch from the middle of the cooling water passage 145. The branch path 147 is configured to supply cooling water toward the heat exchanger 148 and return the cooling water that has passed through the heat exchanger 148 to the cooling water flow path 145.

  The heat exchanger 148 as a heat exchanging portion of the present invention is interposed at a position between the turbine 143 and the condenser 144 in the steam outlet path 141. The heat exchanger 148 can heat the cooling water in the branch path 147 by heat exchange between the liquid cooling water condensed through the condenser 144 and the steam through the turbine 143. It is configured.

  A three-way valve 149 is interposed at a branch point between the cooling water passage 145 and the branch passage 147.

<Configuration of cooling water injection unit>
As described above, the cooling water injection unit 150 is connected to the cooling water supply pump 146. The cooling water injection unit 150 has the following configuration so that liquid cooling water can be injected toward the inner wall surfaces of the lower jacket 123 and the upper jacket 134 in accordance with the operating state of the engine.

  The engine block 110 is equipped with a plurality of nozzles 151 (151A to 151E). The plurality of nozzles 151 are provided corresponding to different positions in the engine block 110 and configured to inject liquid cooling water onto the inner wall surfaces of the lower jacket 123 and the upper jacket 134.

  Specifically, the nozzle 151 has the same structure as that of the fuel injection nozzle, and is configured so that the cooling water can be jetted vigorously in the form of fine droplets.

  The nozzle 151 </ b> A is attached to the cylinder head 130. The nozzle 151 </ b> A is provided on the inner wall surface of the upper jacket 134 between the adjacent exhaust ports 132 and corresponding to a position near the combustion chamber CC.

  The nozzle 151B is mounted on the cylinder block 120. The nozzle 151B is an upper end portion of the inner wall surface of the lower jacket 123 on the cylinder 121 side, and is provided so as to correspond to a position in the vicinity of the combustion chamber CC.

  The nozzle 151C is attached to the cylinder head 130. The nozzle 151 </ b> C is provided so as to correspond to a position between adjacent combustion chambers CC on the inner wall surface of the upper jacket 134.

  The nozzle 151D is attached to the cylinder head 130. The nozzle 151D has both end portions in the cylinder arrangement direction of the inner wall surface of the upper jacket 134 (for example, in the case of an in-line four-cylinder engine, the front end portion of the No. 1 cylinder and the rear end portion of the No. 4 cylinder). However, it is provided so as to correspond to a position in the vicinity of the combustion chamber CC.

  The nozzle 151E is attached to the cylinder block 120. The nozzle 151E is provided so as to correspond to a position slightly below the upper end portion of the inner wall surface of the lower jacket 123 on the cylinder 121 side.

  The nozzles 151A, 151B, 151C, 151D, and 151E are connected to the cooling water supply pump 146 via the cooling water supply path 152.

  A plurality of nozzle control valves 153 are interposed in the cooling water supply path 152. The nozzle control valve 153 includes an on-off valve, and is configured to switch whether or not the cooling water is injected from the nozzle 151. That is, the nozzle control valves 153A, 153B, 153C, 153D, and 153E are configured and arranged so as to switch the presence / absence of cooling water injection in the nozzles 151A, 151B, 151C, 151D, and 151E, respectively.

  The cooling water injection unit 150 changes the open / close state of the nozzle control valves 153A, 153B, 153C, 153D, and 153E under the control of the electronic control unit (ECU) 160 according to the operating state of the engine, so that the nozzle 151A , 151B, 151C, 151D, and 151E, the cooling water injection state can be changed.

<Configuration of control unit>
The engine waste heat recovery system 100 includes an electronic control unit (ECU) 160, a block wall temperature sensor 161, a head wall temperature sensor 162, a steam temperature sensor 163, and a steam pressure sensor 164.

  The ECU 160 includes a CPU, a ROM, a RAM, an interface, and the like. The ROM stores in advance a routine (program) executed by the CPU, a table (lookup table, map), parameters, and the like that are referred to when the routine is executed. The RAM can temporarily store data as needed during routine execution by the CPU. The ECU 160 is electrically connected to the cooling water supply pump 146, the three-way valve 149, the nozzle control valve 153, the block wall temperature sensor 161, the head wall temperature sensor 162, the steam temperature sensor 163, and the steam pressure sensor 164 via an interface. Has been.

  The block wall temperature sensor 161 as the block temperature sensor of the present invention is configured to generate an output corresponding to the temperature of the cylinder block 120. The block wall temperature sensor 161 is provided at a position at the highest temperature at the upper end of the cylinder block 120. Specifically, the block wall temperature sensor 161 is between adjacent cylinders 121 closer to the center in the cylinder arrangement direction (for example, between the No. 2 cylinder and the No. 3 cylinder in the case of an in-line four-cylinder engine). , Provided in the vicinity of the combustion chamber CC.

  The head wall temperature sensor 162 as the block temperature sensor of the present invention is configured to generate an output corresponding to the temperature of the cylinder head 130. The head wall temperature sensor 162 is provided at a position in the cylinder head 130 where the temperature is highest. Specifically, the head wall temperature sensor 162 is located near the exhaust port 132 corresponding to the cylinder 121 closest to the center in the cylinder arrangement direction (for example, No. 2 cylinder and No. 3 cylinder in the case of an in-line four-cylinder engine). (Between adjacent exhaust ports 132).

  The steam temperature sensor 163 and the steam pressure sensor 164 are interposed in the steam outlet path 141. The steam temperature sensor 163 is configured to generate an output corresponding to the temperature of the steam in the steam outlet path 141. The vapor pressure sensor 164 is configured to generate an output corresponding to the vapor pressure in the vapor outlet path 141.

  ECU160 which comprises the abnormality determination part of this invention, the abnormality alerting | reporting part, and the abnormality time operation control part controls operation | movement of each part of an engine or the engine waste heat recovery system 100 based on the output signal from each above-mentioned sensor. It is configured as follows.

  That is, ECU 160 drives cooling water supply pump 146 based on the output of block wall temperature sensor 161 or head wall temperature sensor 162 when the temperature of cylinder block 120 or cylinder head 130 is equal to or higher than a predetermined injection start temperature. By controlling the open / closed state of the nozzle control valves 153A to 153E, the liquid cooling water is jetted toward the inner wall surfaces of the lower jacket 123 and the upper jacket 134 by the nozzles 151A to 151E.

  The ECU 160 determines whether or not an abnormality has occurred based on the outputs of the steam temperature sensor 163 and the steam pressure sensor 164, and if an abnormality has been determined, the ECU 160 detects the occurrence of the abnormality by a warning lamp (not shown). It is comprised so that it may alert | report.

  Further, ECU 160 is configured to control the engine operating state to a predetermined abnormal operation mode (default mode) when occurrence of abnormality is determined.

<Operation of Engine Waste Heat Recovery System of Embodiment>
Hereinafter, the operation of the engine waste heat recovery system 100 of the present embodiment having the above-described configuration will be described with reference to the reference numerals in FIG.

<< Waste heat recovery operation >>
FIG. 2 is a table showing how the cooling water injection unit 150 shown in FIG. 1 operates in accordance with the temperature of the cylinder block 120 (block wall temperature). FIG. 3 is a graph showing the operation of the cooling water injection unit 150 in time series corresponding to FIG. A plurality of tables in FIG. 2 are prepared according to the coolant temperature and the operation history (accumulated fuel injection amount, etc.).

  Referring to FIGS. 2 and 3, the cooling water supply pump 146 is stopped and the nozzle control valves 153A to 153E are all closed until the block wall temperature reaches TA immediately after the engine is started. Therefore, the cooling water is not jetted by the nozzle 151.

  When the block wall temperature reaches TA or higher, the cooling water supply pump 146 operates and the open / close state of the nozzle control valves 153A to 153E is controlled. Then, cooling water is sprayed from the nozzle 151 toward specific portions of the inner wall surfaces of the lower jacket 123 and the upper jacket 134 (spray cooling). As a result, the portion is cooled, and the cooling water evaporates to generate saturated steam.

  When the block wall temperature is TA or more and less than TB, the operating voltage of the cooling water supply pump 146 is set to VA, and only 153A of the nozzle control valves 153A to 153E is opened (the others are closed: The same). Then, cooling water is jetted from the nozzle 151A (spray cooling 1). As a result, the cooling portion A (the portion between the adjacent exhaust ports 132 on the inner wall surface of the upper jacket 134 and in the vicinity of the combustion chamber CC) facing the nozzle 151A is cooled, and the cooling portion A is placed in the upper jacket 134. Saturated steam is generated.

  In this case, the cooling water temperature is low. Therefore, in this case, the three-way valve 149 causes the most upstream portion (portion between the condenser 144 and the three-way valve 149) in the cooling water passage 145 and the branch passage 147 to communicate with each other, and the most upstream portion and the cooling water passage 145 Direct communication with the downstream side of the three-way valve 149 is blocked.

  Then, the cooling water that has passed through the condenser 144 flows to the heat exchanger 148 via the branch path 147. In this heat exchanger 148, the cooling water heading for the cooling water injection unit 150 is heated by heat exchange with steam. Thereby, the thermal shock to the cylinder head 130 due to the injection of the cooling water is mitigated, and the saturated vaporization of the cooling water is accelerated.

  When the block wall temperature is equal to or higher than TB and lower than TC, the operating voltage of the cooling water supply pump 146 is set to VB higher than VA, and the nozzle control valves 153A to 153E 153A and 153B are opened. Then, cooling water is jetted from the nozzles 151A and 151B (spray cooling 2). Thereby, in addition to the cooling portion A, the cooling portion B (the upper end portion of the inner wall surface on the cylinder 121 side of the lower jacket 123 and in the vicinity of the combustion chamber CC) facing the nozzle 151B is cooled, Saturated steam is generated in the lower jacket 123 and the upper jacket 134.

  When the block wall temperature is equal to or higher than TC and lower than TD, the operating voltage of the cooling water supply pump 146 is set to VC higher than VB, and the nozzle control valves 153A to 153E 153A to 153C are opened. Then, cooling water is jetted from the nozzles 151A to 151C (spray cooling 3). Thereby, in addition to the cooling portions A and B, the cooling portion C (the portion between the adjacent combustion chambers CC on the inner wall surface of the upper jacket 134) facing the nozzle 151C is cooled, and the lower jacket 123 and the upper Saturated steam is generated in the jacket 134.

  In this case, the three-way valve 149 blocks communication between the most upstream part and the branch path 147 in the cooling water flow path 145, and the most upstream part and the downstream side of the cooling water flow path 145 from the three-way valve 149 are directly connected. Communicated. That is, the heat exchanger 148 is bypassed. Thereby, cooling efficiency becomes favorable.

  When the block wall temperature is equal to or higher than TD and lower than TE, the operating voltage of the cooling water supply pump 146 is set to VD higher than VC, and the nozzle control valves 153A to 153E 153A to 153D are opened. Then, cooling water is jetted from the nozzles 151A to 151D (spray cooling 4). As a result, in addition to the cooling portions A to C, the cooling portion D that faces the nozzle 151D (both ends of the inner wall surface of the upper jacket 134 in the cylinder arrangement direction and in the vicinity of the combustion chamber CC) is cooled. At the same time, saturated steam is generated in the lower jacket 123 and the upper jacket 134.

  When the block wall temperature is equal to or higher than TE, the operating voltage of the cooling water supply pump 146 is set to VE higher than VD, and all of the nozzle control valves 153A to 153E are opened. Then, cooling water is jetted from the nozzles 151A to 151E (spray cooling 5). Thereby, in addition to the cooling parts A to D, the cooling part E facing the nozzle 151E (the part slightly below the upper end of the inner wall surface on the cylinder 121 side of the lower jacket 123: that is, the part slightly below the cooling part B) ) Is cooled, and saturated steam is generated in the lower jacket 123 and the upper jacket 134.

  The saturated steam generated in the lower jacket 123 and the upper jacket 134 in this way is led out to the steam lead-out path 141 through the steam outlet 135 provided at the uppermost part of the upper jacket 134.

  The steam led out to the steam lead-out path 141 is heated by the heat exchange with the exhaust gas in the superheater 142 to become superheated steam. The superheated steam generated in the superheater 142 rotates the rotating blades by expansion in the turbine 143. As a result, the thermal energy of the superheated steam is converted into the movement (rotation) energy of the rotating blades of the turbine 143. That is, mechanical energy is recovered from the superheated steam.

  The steam that has become low energy through the turbine 143 is condensed by being cooled by the condenser 144. The cooling water that has become liquid in the condenser 144 is supplied again to the cooling water supply pump 146 via the cooling water flow path 145.

<< Abnormality detection / operation control during abnormality >>
FIG. 4 is a flowchart showing an abnormality detection routine 400 executed by ECU 160 shown in FIG. Hereinafter, the abnormality detection and the abnormal operation control operation of the engine waste heat recovery system 100 of the present embodiment will be described with reference to FIG. 4 and the reference numerals of FIG. 1 as necessary.

  In this operation example, unlike the above-described operation example, the cooling water supply pump 146 operates under the following conditions: (1) When the block wall temperature Te is lower than a predetermined temperature TA (for example, 105 ° C.), The cooling water supply pump 146 is stopped. (2) When the block wall temperature Te is equal to or higher than TA, when the engine speed Ne is equal to or higher than the predetermined value Ne1 and the fuel injection amount G in the current cycle is equal to or higher than the predetermined value G1, the cooling water supply pump 146 Driven by the drive voltage V1. (3) Even when the block wall temperature Te is equal to or higher than TA, the cooling water supply pump 146 is stopped when the engine speed Ne is less than Ne1 or the fuel injection amount G is less than G1.

Moreover, in this operation example, the Antoine formula representing the relationship between the steam temperature and the steam pressure.
LogP = X− (Y / (T + Z))
(P is the water vapor pressure [mmHg], T is the water vapor temperature [° C.], X to Z are constants,
X = 8.002754, Y = 1705.616, Z = 231.505)
On the basis of the above, when the steam temperature and the steam pressure do not satisfy the following relationship, an abnormality of the steam temperature sensor 163 and the steam pressure sensor 164 or an abnormality of the engine waste heat recovery system 100 such as a steam leak is detected. It has become.
P = (10 ^α ) ± β
(Α = X− (Y / (T + Z),
β is a constant that takes into account variations in vapor pressure, β = 50)

  This routine 400 is repeatedly executed at every predetermined timing (for example, every predetermined time). In the following flowchart, the block wall temperature Te is a detected value of the block wall temperature based on the output of the block wall temperature sensor 161, and the steam temperature Tv is a detected value of the steam temperature based on the output of the steam temperature sensor 163, The vapor pressure Pv is a detected value of the vapor pressure based on the output of the vapor pressure sensor 164.

  When the routine 400 is started, first, at step 405 (hereinafter, step is abbreviated as “S”), it is determined whether or not the block wall temperature Te is equal to or higher than TA. When the block wall temperature Te is less than TA (S405 = No), the process proceeds to S410, the cooling water supply pump 146 is stopped, and this routine is once ended. When the block wall temperature Te is equal to or higher than TA (S405 = Yes), the process proceeds to S415.

  In S415, it is determined whether or not the engine speed Ne is Ne1 or more. When the engine speed Ne is less than Ne1 (S415 = No), the process proceeds to S410, the cooling water supply pump 146 is stopped, and this routine is once ended. If the engine speed Ne is equal to or greater than the predetermined value Ne1 (S415 = Yes), the process proceeds to S420.

  In S420, it is determined whether or not the fuel injection amount G is G1 or more. When the fuel injection amount G is less than G1 (S420 = No), the process proceeds to S410, the cooling water supply pump 146 is stopped, and this routine is once ended. When the fuel injection amount G is G1 or more (S420 = Yes), the process proceeds to S425.

  In S425, the cooling water supply pump 146 starts to be driven with the normal operating voltage V1, and the cooling water injection in the nozzle 151 is started. After that, in S430, the system waits until a predetermined time t1 has elapsed from the start of driving of the cooling water supply pump 146.

  When the predetermined time t1 has elapsed from the start of driving of the cooling water supply pump 146 (S430 = Yes), in S440, the steam temperature Tv is between a predetermined temperature Tb (for example, 240 ° C.) and a predetermined temperature Tc (for example, 325 ° C.). It is determined whether or not there is.

  When the steam temperature Tv is between Tb and Tc (S440 = Yes), the process proceeds to S445, and the steam pressure Pv is Pd-50 (Pd is the value of P when T = Tb is substituted into the Antoine equation). And Pe + 50 (Pe is the value of P when T = Tc is substituted into the Antoine equation). When Pv is between Pd−50 and Pe + 50 (S445 = Yes), this routine is once ended.

  When the steam temperature Tv is not between Tb and Tc (S440 = No), the process proceeds to S450. In S450, it is determined whether or not the steam temperature Tv is lower than Tb.

  When the steam temperature Tv is lower than Tb (S450 = Yes), the process proceeds to S455. In S445, it is determined whether or not the vapor pressure Pv is lower than Pd + 50. When the vapor pressure Pv is lower than Pd + 50 (S455 = Yes), the process proceeds to S410, the cooling water supply pump 146 is stopped, and this routine is once ended.

  When the steam temperature Tv is not lower than Tb (S450 = No), the process proceeds to S460. In S460, it is determined whether or not the steam temperature Tv is higher than Tc. When the steam temperature Tv is higher than Tc (S460 = Yes), the detected temperature of the steam temperature Tv by the steam temperature sensor 163 is higher than the maximum temperature of steam during normal operation.

  Therefore, in this case, it is considered that an abnormality of the engine waste heat recovery system 100 (an abnormality of the steam temperature sensor 163, a lack of cooling water, etc.) has occurred. Therefore, the process proceeds to S465, and the cooling water supply pump 146 is driven at a voltage V2 higher than the normal driving voltage V1 for a predetermined time, and then driven at a higher voltage V3 for a predetermined time. Thereafter, the process proceeds to S470, where the engine operation mode is set to a default mode (a mode in which only a constant low load operation is possible regardless of the accelerator opening), and this routine is once ended.

  When the steam temperature Tv is not between Tb and Tc, is not lower than Tb, and is not higher than Tc (S440 = No → S450 = No → S460 = No), it is logically impossible. Therefore, in this case, it is assumed that the engine waste heat recovery system 100 is abnormal, in particular, the steam temperature sensor 163 has failed and there is no output from the steam temperature sensor 163 or an abnormal value. Therefore, in this case, the process proceeds to S470, the engine operation mode is set to the default mode, and this routine is once ended.

  Despite the vapor temperature Tv being lower than Tb, the vapor pressure Pv is Pd + 50 (Pd is the vapor pressure when T = Tb is substituted into the Antoine equation. Pd + 50 is the case where the vapor temperature is Tb considering variation (S450 = Yes → S455 = No), the detected value of the vapor pressure by the vapor pressure sensor 164 is higher than the original vapor pressure. That is, it is assumed that an abnormality of the engine waste heat recovery system 100 (an abnormality of the vapor pressure sensor 164 or the like) has occurred. Therefore, in this case, the process proceeds to S470, the engine operation mode is set to the default mode, and this routine is once ended.

  Despite the steam temperature Tv between Tb and Tc, Pv is between Pd−50 and Pe + 50 (Pd is the value of P when T = Tb is substituted for the Antoine equation, Pe is the Antoine equation) If T = the value of P when Tc is substituted) (S440 = Yes → S445 = No), there is a discrepancy between the output of the steam temperature sensor 163 and the output of the steam pressure sensor 164. That is, it is assumed that an abnormality of the engine waste heat recovery system 100 (an abnormality of the steam temperature sensor 163, an abnormality of the steam pressure sensor 164, etc.) has occurred. Therefore, in this case, in this case, the process proceeds to S470, the engine operation mode is set to the default mode, and this routine is once ended.

<Effects of Configuration of Embodiment>
Hereinafter, effects of the configuration of the present embodiment as described above will be described.

  -According to the configuration of the present embodiment, the operating states of the cooling water supply pump 146, the nozzle 151, and the nozzle control valve 153 are controlled according to the operating state of the engine, so that the nozzle 151 (151A to 151E) The injection state (injection timing, injection pressure, injection water amount, and injection part) of the cooling water is appropriately controlled according to the engine operating state. Therefore, cooling of the engine block 110 and waste heat recovery can be performed more appropriately.

  In the configuration of the present embodiment, the cooling water in the form of fine droplets is jetted vigorously on the inner wall surfaces of the lower jacket 123 and the upper jacket 134 by the cooling water jet unit 150. That is, liquid cooling water collides with the inner wall surface vigorously.

  Thereby, the bubble by the vapor | steam of the cooling water adhering to the said inner wall surface is blown off favorably. Therefore, even when the engine block 110 (particularly near the exhaust port 132 in the cylinder head 130) becomes hot due to high load operation or the like and a large amount of bubbles are generated on the inner wall surface, the film boiling phenomenon occurs. Can be mitigated or suppressed.

  Therefore, according to this configuration, the engine block 110 (particularly, the vicinity of the exhaust port 132 in the cylinder head 130) is cooled well.

  Further, the temperature rise and vaporization of the cooling water by the waste heat generated in the engine block 110 is efficiently performed. Therefore, the recovery efficiency of mechanical energy from waste heat becomes good.

  According to the configuration of the present embodiment, the cooling water that has passed through the condenser 144 is heated in the heat exchanger 148 by heat exchange with the steam that has passed through the turbine 143. As a result, a part of the heat of the steam that has passed through the turbine 143 is again taken into the cooling water sent toward the cooling water injection unit 150 without being discarded outside by the condenser 144. Therefore, the cooling loss in the engine waste heat recovery system 100 can be further reduced.

  In addition, according to this configuration, the cooling water delivered toward the cooling water injection unit 150 is heated, so that the thermal shock in the cylinder head 130 due to the injection of the cooling water from the nozzle 151 is alleviated. In addition, saturated vaporization of the cooling water is promoted.

<List of examples of modification>
Note that, as described above, the above-described embodiments are merely examples of typical embodiments of the present invention that the applicant has considered to be the best at the time of filing of the present application. Therefore, the present invention is not limited to the above-described embodiment. Therefore, it goes without saying that various modifications can be made to the above-described embodiment without departing from the essential part of the present invention.

  Hereinafter, some typical modifications will be exemplified. In the following description of modifications, members having the same configuration and function as those described in the above-described embodiment are denoted by the same reference numerals as those in the above-described embodiment. Moreover, within the range which is not technically contradictory, description in the above-mentioned embodiment shall be used.

  However, it goes without saying that the modifications are not limited to those listed below. In addition, a plurality of modified examples can be applied in a composite manner as appropriate within a technically consistent range.

  The present invention (especially those expressed functionally and functionally in the constituent elements constituting the means for solving the problems of the present invention) is based on the above-described embodiment and the description of the following modifications. Should not be construed as limited. Such a limited interpretation is unacceptable and improper for imitators, while improperly harming the applicant's interests (rushing to file under a prior application principle).

  (A) The application target of the present invention is not limited to an inline engine. For example, the present invention can be suitably applied to any of V type, W type, and horizontally opposed type.

  Moreover, the application object of this invention is not limited to a gasoline engine. For example, the present invention can be applied to a diesel engine.

  (B) In the present invention, the number of valves is not limited. That is, the number of intake ports 131 and exhaust ports 132 is not limited.

  (C) The rotational energy of the rotary blades provided in the turbine 143 may be converted into electricity, or may be used as a power source for other rotational drive systems.

  Moreover, it replaces with the turbine 143 and the mechanism provided with the piston may be used.

  (D) There is no limitation on the configuration and driving method of the cooling water supply pump 146.

  For example, the cooling water supply pump 146 may be configured to receive a driving force generated at the output shaft of the engine via a power transmission mechanism including a clutch.

  Alternatively, the cooling water supply pump 146 may be configured to receive the driving force generated by the rotating blades of the turbine 143 via a power transmission mechanism.

  Alternatively, the cooling water supply pump 146 may be configured to be rotationally driven by electrical energy recovered via the turbine 143.

  (E) Various aspects other than the aspect shown in the flowchart of FIG. 4 may be used for the operation of abnormality detection and processing at the time of abnormality.

  For example, the block wall temperature Te may be based on the output of the head wall temperature sensor 162.

  Further, the relationship between the steam temperature and the steam pressure used for abnormality detection is not limited to the Antoine type. For example, the Clausius-Clapeyron equation may be used.

  (F) Instead of acquiring temperature and pressure by a sensor, estimation of temperature and pressure based on the engine operation history may be performed.

  (G) The default mode is not limited to the aspect described in the above embodiment. Alternatively, when the engine waste heat recovery system 100 is mounted on a hybrid vehicle, the “default mode” may be a mode that prohibits the operation by the engine and permits only the operation by the motor.

  (H) Other elements that are functionally expressed in the elements constituting the means for solving the problems of the present invention are the specific structures disclosed in the above-described embodiments and modifications. In addition, any structure capable of realizing the operation / function is included.

1 is a schematic configuration diagram of an engine waste heat recovery system according to an embodiment of the present invention. It is a table | surface which shows the mode of operation | movement according to block wall temperature of the cooling water injection part shown by FIG. FIG. 3 is a graph showing the state of operation of the cooling water injection unit in time series corresponding to FIG. 2. It is a flowchart which shows the abnormality detection routine performed by the electronic control unit (ECU) shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Engine waste heat recovery system 110 ... Engine block 120 ... Cylinder block 123 ... Lower jacket 130 ... Cylinder head 132 ... Exhaust port 133 ... Exhaust passage 134 ... Upper jacket 135 ... Steam exhaust port 140 ... Waste heat recovery part 141 ... Steam extraction Path 142 ... Superheater 143 ... Turbine 144 ... Condenser 145 ... Cooling water flow path 146 ... Cooling water supply pump 147 ... Branching path 148 ... Heat exchanger 150 ... Cooling water injection section 151 ... Nozzle 152 ... Cooling water supply path 153 ... Nozzle control Valve 160 ... Electronic control unit (ECU) 161 ... Block wall temperature sensor 162 ... Head wall temperature sensor 163 ... Steam temperature sensor 164 ... Steam pressure sensor CC ... Combustion chamber

Claims (6)

In an engine waste heat recovery system configured to recover mechanical energy from engine waste heat,
An engine block formed with a cylinder, a combustion chamber, an exhaust passage communicating with the combustion chamber, and a coolant jacket provided adjacent to the cylinder, the combustion chamber, and the exhaust passage;
A cooling medium injection unit configured to inject a liquid cooling medium toward the inner wall surface of the cooling medium jacket;
A vapor outlet path connected to the cooling medium jacket and configured to extract the vapor of the cooling medium vaporized after being injected by the cooling medium injection unit to the outside of the cooling medium jacket;
A steam heater that is interposed in the steam lead-out path and configured to heat the steam by heat exchange between the exhaust gas passing through the exhaust passage and the steam;
An expander interposed in the steam outlet and configured to recover mechanical energy from the steam that has passed through the steam heater;
A condenser interposed in the steam outlet path and configured to condense the steam that has passed through the expander;
A cooling medium supply pump configured to supply the liquid cooling medium condensed through the condenser to the cooling medium injection unit according to an operating state of the engine;
An engine waste heat recovery system characterized by comprising: The engine waste heat recovery system according to claim 1,
A block temperature sensor configured to generate an output corresponding to the temperature of the engine block;
The cooling medium supply pump supplies the liquid cooling medium to the cooling medium injection unit based on the output of the block temperature sensor when the temperature of the engine block is equal to or higher than a predetermined injection start temperature. An engine waste heat recovery system characterized by being configured as described above. The engine waste heat recovery system according to claim 1 or 2,
The cooling medium injection unit is
Comprising a plurality of nozzles provided corresponding to a plurality of positions in the engine block;
An engine waste heat recovery system configured to change an injection state of the cooling medium in the plurality of nozzles according to an operating state of the engine. The engine waste heat recovery system according to any one of claims 1 to 3,
The engine further comprising a heat exchanging unit for exchanging heat between the liquid cooling medium delivered toward the cooling medium ejecting unit and the steam having passed through the expander. Waste heat recovery system. The engine waste heat recovery system according to any one of claims 1 to 4,
A steam temperature sensor interposed in the steam lead-out path and configured to generate an output corresponding to the temperature of the steam;
A vapor pressure sensor interposed in the vapor outlet path and configured to generate an output corresponding to the pressure of the vapor;
An abnormality determination unit that determines whether or not an abnormality has occurred based on outputs of the steam temperature sensor and the vapor pressure sensor;
An abnormality notifying unit for notifying the occurrence of an abnormality when the occurrence of an abnormality is determined by the abnormality determining unit;
An engine waste heat recovery system, further comprising: The engine waste heat recovery system according to claim 5,
The engine waste heat, further comprising: an abnormal operation control unit that controls the operation state of the engine to a predetermined abnormal operation mode when occurrence of an abnormality is determined by the abnormality determination unit. Collection system.

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