JP2009002183A - Engine waste heat recovery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste heat recovery device efficiently recovering coolant absorbing engine waste heat and evaporating. <P>SOLUTION: The waste heat recovery device (1) of an engine (2) of the invention separately has a block side water jacket (6) provided on a cylinder block (4) and a head side water jacket (7) provided on a cylinder head (5) and comprises a power recoverer (19) recovering waste heat of the engine (2) through the coolant respectively evaporating in the block side water jacket (6) and in the head side water jacket (7) so that recovery efficiency of the waste heat of the engine (2) can be improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a waste heat recovery apparatus that recovers waste heat in an engine via steam.

  2. Description of the Related Art Conventionally, there is known a waste heat recovery device that recovers waste heat generated by driving an internal combustion engine (engine) using a Rankine cycle. In such a waste heat recovery apparatus, for example, the engine water-cooled cooling system has a sealed structure, the cooling water evaporated by the waste heat in the engine, that is, the expander (turbine) is driven by steam, and the heat of the steam There is one that converts energy into electrical energy and recovers it. For example, Patent Document 1 discloses an improved version of such a waste heat recovery apparatus.

JP 2000-345835 A

  By the way, when the engine is operated and the warming-up proceeds, the temperature of each part of the engine rises. Since each engine part is affected differently by the combustion and exhaust of the engine for each part, the temperature distribution in the engine is not uniform. In other words, a temperature difference may occur between one part of the engine and another part. For example, if the material that forms the cylinder head of the engine and the material that forms the cylinder block are different, the temperature during warm-up rises more quickly with a material with higher thermal conductivity. The part formed with a high material may become high temperature. Further, the cylinder head formed near the combustion chamber and through which the exhaust gas passes becomes higher in temperature than the cylinder block. Furthermore, when attention is paid only to the cylinder head, the exhaust side through which the exhaust gas passes becomes hotter than the intake side. Also, when attention is paid to the cylinder block, the inside where heat is likely to be stored is higher in temperature than the outside where heat is easily released.

  However, in the cooling path formed in the engine as in Patent Document 1, a portion where the temperature at which the refrigerant evaporates is mixed with a portion lower than the temperature at which the refrigerant evaporates, so that steam is efficiently collected. Absent.

  Then, this invention makes it a subject to provide the waste-heat recovery apparatus which collect | recovers efficiently the refrigerant | coolant which absorbs the waste heat of an engine and evaporates.

  The engine waste heat recovery apparatus of the present invention that solves such a problem includes two or more evaporation chambers that generate steam by the waste heat of the engine, and power that recovers the engine waste heat via the steam generated in the evaporation chamber. And a recovery machine, wherein the steam generated in each of the evaporation chambers is caused to flow into the power recovery machine (claim 1). By setting it as such a structure, waste heat can be collect | recovered for every engine part in which the evaporation chamber was formed, and the efficiency of waste heat recovery can be improved. The generation of steam in the evaporation chamber inside the engine depends on the temperature at the location where the steam is generated. Since each engine part has a different time required for warm-up, the time when steam is generated is different. Depending on the temperature rise characteristics of such an engine, an evaporation chamber is provided for each steam generation location, and waste heat can be recovered by the steam generated for each evaporation chamber thus provided. Efficiency can be improved.

  In such a waste heat recovery apparatus for an engine, the evaporation chamber can be provided at two or more locations where the temperatures are different (claim 2). By setting it as such a structure, the vapor | steam which generate | occur | produces in advance from the location where temperature is high is recoverable. Furthermore, even when the temperature is low, when warm-up proceeds and reaches a temperature at which the refrigerant can evaporate, steam is generated, so that waste heat can be recovered. In this manner, waste heat can be recovered in the order in which steam is generated.

  In such an engine waste heat recovery apparatus, in particular, the cylinder head has a faster temperature rise than the cylinder block, and the temperature rises early, so the evaporation chamber can be provided in the cylinder head and the cylinder block. (Claim 3). By adopting such a configuration, the refrigerant in the cylinder head that reaches a temperature that can evaporate earlier than the refrigerant in the cylinder block is used for the recovery of waste heat prior to the refrigerant in the cylinder block. be able to.

  By the way, conventionally, a general engine is cooled by a refrigerant circulated to a water jacket formed in a cylinder head and a cylinder block. In such a water jacket, the water jacket on the cylinder head side and the water jacket on the cylinder block side communicate with each other, and refrigerant flows back and forth. The engine waste heat recovery apparatus according to the present invention may be configured to include a refrigerant flow suppressing means disposed between a cylinder head and a cylinder block of an engine having such a water jacket. . With such a configuration, the water jacket formed on the conventional engine can be used to form the evaporation chamber on the cylinder head side and the evaporation chamber on the cylinder block side. A waste heat recovery apparatus can be configured. Such a refrigerant flow suppression means can be, for example, a head gasket in which a refrigerant flow hole is closed.

  In such a waste heat recovery apparatus for an engine, the power recovery machine includes a collection part where steam generated in each of the evaporation chambers gathers, and an expander that operates by the steam gathered in the gathering part. It can be set as a structure (Claim 5). By setting it as such a structure, the refrigerant | coolant which evaporated in the some evaporation chamber can be put together into one, and can be made to flow into an expander. Further, the collecting portion may be arranged to receive heat from the exhaust gas of the engine (claim 6). By setting it as such a structure, steam can be heated from the exhaust gas which has the waste heat of an engine, and the recovery efficiency of waste heat can be improved.

  Such an engine waste heat recovery device may include a check valve disposed in the steam passage and configured to block the flow of the refrigerant from the power recovery machine toward the evaporation chamber. ). By setting it as such a structure, the backflow of a vapor | steam can be suppressed.

  The engine waste heat recovery apparatus of the present invention can recover waste heat from each part of the engine that has reached the temperature at which the refrigerant evaporates by providing an evaporation chamber in which the refrigerant evaporates according to the temperature rise characteristics of the engine. It is possible to increase the efficiency of waste heat recovery.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of an engine 2 in which a waste heat recovery apparatus 1 of this embodiment is incorporated. The engine 2 includes a piston 3, a cylinder block 4, and a cylinder head 5. The cylinder block 4 is formed with a block-side water jacket 6 through which refrigerant passes. In the cylinder head 5, a head-side water jacket 7 through which refrigerant passes is formed around the intake valve 8 and the exhaust valve 9 assembled to the cylinder head 5. The block-side water jacket 6 and the head-side water jacket 7 are formed independently, and refrigerant does not go back and forth between them. The block-side water jacket 6 and the head-side water jacket 7 thus formed correspond to the evaporation chamber of the present invention. Further, the steam generated in each of the block-side water jacket 6 and the head-side water jacket 7 formed in this way flows into a power recovery machine 19 described later.

  The waste heat recovery apparatus 1 further includes a first injection nozzle 10a to a sixth injection nozzle 10f, a refrigerant path 11, a pump 12, a first temperature sensor 13a to a fourth temperature sensor 13f, and an ECU (Electronic Control Unit) 15. . The waste heat recovery apparatus 1 includes a recovery path 16, a first steam path 17a, and a second steam path 17b. In the recovery path 16, the power recovery unit 19, the condenser 20, and the refrigerant tank 21 are arranged in this order from the side close to the block-side water jacket 6 or the head-side water jacket 7. The power recovery machine 19 includes a superheater 23, an expander 24, and a generator 25, and recovers waste heat of the engine 2 through steam generated in the block-side water jacket 6 and the head-side water jacket 7.

  The first injection nozzle 10 a to the sixth injection nozzle 10 f inject refrigerant into different cooling portions in the block-side water jacket 6 and the head-side water jacket 7. The first injection nozzle 10 a and the second injection nozzle 10 b are mounted on the cylinder block 4 with their injection ports exposed in the block-side water jacket 6. The injection port of the first injection nozzle 10a and the injection port of the second injection nozzle 10b are arranged so as to inject refrigerant toward the side surface of the block-side water jacket 6 on the cylinder bore wall 6a side.

  The third injection nozzle 10c, the fourth injection nozzle 10d, the fifth injection nozzle 10e, and the sixth injection nozzle 10f are mounted on the cylinder head 5 with their injection ports exposed in the head-side water jacket 7. The injection port of the third injection nozzle 10c and the injection port of the fourth injection nozzle 10d are arranged so as to inject the refrigerant toward the intake valve 8, and the injection port of the fifth injection nozzle 10e and the sixth injection nozzle 10f are The refrigerant is injected toward the exhaust valve 9 side.

  One end of the refrigerant path 11 is connected to the pump 12. The refrigerant path 11 is branched in the middle of the path, and each of the branched ends is connected to the first injection nozzle 10a to the sixth injection nozzle 10f. A refrigerant is supplied from the pump 12 to each injection nozzle through the refrigerant path 11.

  The pump 12 is a pump that controls the injection pressure at each injection nozzle. The pump 12 is electrically connected to the ECU 15, and pumps the refrigerant from the refrigerant tank 21 based on a signal transmitted from the ECU 15, pressurizes the refrigerant, and pumps the refrigerant to each injection nozzle.

  The first temperature sensor 13a to the sixth temperature sensor 13f are mounted at the refrigerant injection location of each injection nozzle. That is, the first temperature sensor 13a is mounted on the wall surface of the cylinder block 4 corresponding to the cooling portion where the first injection nozzle 10a injects the refrigerant, and the second temperature sensor 13b is injected by the second injection nozzle 10b. It is mounted on the wall surface of the cylinder block 4 corresponding to the cooling part. Further, the third temperature sensor 13c is mounted in the vicinity of the intake valve 8 corresponding to the cooling portion where the third injection nozzle 10c injects the refrigerant, and the fourth temperature sensor 13d is injected by the fourth injection nozzle 10d. It is mounted in the vicinity of the intake valve 8 corresponding to the cooling part. In addition, the fifth temperature sensor 13e is mounted in the vicinity of the exhaust valve 9 corresponding to the cooling part where the fifth injection nozzle 10e injects the refrigerant, and the sixth temperature sensor 13f is injected by the sixth injection nozzle 10f. It is mounted in the vicinity of the exhaust valve 9 corresponding to the cooling part. These temperature sensors are electrically connected to the ECU 15, and the ECU 15 acquires temperature information of each part.

  Further, the ECU 15 is electrically connected to the first injection nozzle 10a to the sixth injection nozzle 10f, and controls each injection nozzle to execute injection. The ECU 15 injects the refrigerant from the first injection nozzle 10a based on the temperature information acquired from the first temperature sensor 13a. Similarly, the ECU 15 causes the refrigerant to be injected also for the other injection nozzles based on the temperature information acquired from the corresponding temperature sensor.

  The refrigerant thus injected evaporates by absorbing waste heat from the cylinder block 4 and the cylinder head 5 in the block-side water jacket 6 and the head-side water jacket 7. The refrigerant thus evaporated flows into the first vapor path 17a and the second vapor path 17b.

  One end of the first steam path 17 a is connected to the block-side water jacket 6, and the other end is connected to the superheater 23 of the power recovery machine 19. One end of the second steam path 17 b is connected to the head-side water jacket 7, and the other end is connected to the superheater 23. Further, the first steam path 17 a and the second steam path 17 b include a check valve 22 that blocks the flow of refrigerant from the power recovery machine 19 toward the block-side water jacket 6 and the head-side water jacket 7.

  The superheater 23 provided in the power recovery machine 19 corresponds to the assembly part of the present invention. That is, steam generated in the block-side water jacket 6 and the head-side water jacket 7 flows through the first steam path 17a and the second steam path 17b. Further, the superheater 23 is disposed so as to come into contact with an exhaust pipe 26 that exhausts exhaust gas generated by engine combustion to the outside, and transfers heat from the exhaust gas through the exhaust pipe 26 to the steam, Keep it hot.

  The expander 24 is driven by steam that has gathered in the superheater 23 and has reached a high temperature. Further, the expander 24 and the generator 25 are connected by a common rotating shaft 27, and the rotating shaft 27 rotates by driving the expander 24 to drive the generator 25. In the generator 25 driven in this way, the energy of the steam is converted into electric energy and recovered. In addition, it can replace with the generator 25 and can also transmit the drive force of the expander 24 to a crankshaft using a power converter.

  The condenser 20 cools and condenses the refrigerant that has passed through the power recovery machine 19 and returns it to a liquid state. The refrigerant liquefied by the condenser 20 is sent to the refrigerant tank 21 through the recovery path 16. The refrigerant that has flowed into the refrigerant tank 21 is again sucked into the pump 12 and injected into the block-side water jacket 6 or the head-side water jacket 7, and circulates in the system.

  When the engine 2 in which the waste heat recovery apparatus 1 of the present invention configured as described above is assembled is started, warm-up is started and the temperature of each part rises. ECU15 acquires such temperature information via the temperature sensor arrange | positioned at each location, sends an injection instruction | indication to the injection nozzle corresponding to the location which reached the temperature which a refrigerant | coolant evaporates, and injects a refrigerant | coolant. That is, in the head-side water jacket 7 formed in the cylinder head 5 that is warmed up faster than the cylinder block 4, the temperature reaches the temperature at which the refrigerant evaporates early. Be injected. In this way, the waste heat recovery apparatus 1 can inject the refrigerant only at the location where the temperature at which the refrigerant evaporates is reached. The refrigerant thus injected cools the injection part of the refrigerant and absorbs heat to evaporate. The steam generated in this way flows into the power recovery machine 19 through the first steam path 17a and is used for recovery of waste heat.

  On the other hand, the waste heat recovery apparatus 1 promotes warm-up without injecting the refrigerant into a location having a temperature lower than the temperature at which the refrigerant evaporates, for example, the block-side water jacket 6. Even in such a place, when the warm-up proceeds and reaches the temperature at which the refrigerant evaporates, the refrigerant is injected and the waste heat is recovered.

  As described above, the waste heat recovery apparatus 1 according to the present embodiment can recover waste heat at each location where the temperature at which the refrigerant evaporates is reached. The waste heat recovery apparatus 1 recovers waste heat by injecting the refrigerant in order from the place where the temperature at which the refrigerant evaporates is reached to generate steam. Thus, since waste heat is collect | recovered for every location to evaporate, the waste heat of an engine can be collect | recovered efficiently.

  Next, a second embodiment of the present invention will be described. FIG. 2 is an explanatory diagram showing a schematic configuration of the engine 32 in which the waste heat recovery apparatus 31 of the present embodiment is incorporated. The engine 32 of the second embodiment has substantially the same configuration as the engine 2 of the first embodiment. However, the engine 2 has a water jacket 6 formed on the cylinder block 4 and a water jacket 7 is formed on the cylinder head 5 separately. A water gasket 36 on the cylinder block 34 side and the cylinder head 35 side is provided between the conventionally used cylinder block 34 and the cylinder head 35 by disposing a head gasket 37 that closes the hole through which the refrigerant flows. It is different in that it is divided.

  The waste heat recovery apparatus 31 can form an evaporation chamber in which the refrigerant evaporates on the cylinder block 34 side and the cylinder head 35 side by incorporating the head gasket 37. Since such a configuration can use a conventionally used cylinder block and cylinder head, the waste heat recovery apparatus of the present invention can be configured easily and inexpensively. In addition, since the other structure is the same as Example 1, about the component same as Example 1, the same reference number is attached | subjected in drawing and the detailed description is abbreviate | omitted.

  The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited thereto. Various modifications of these embodiments are within the scope of the present invention. It is apparent from the above description that various other embodiments are possible within the scope.

  The evaporation chamber of the present invention can be provided at two or more locations where the temperature will be different as the warm-up proceeds. For example, an evaporation chamber can be provided for each cylinder. In addition, a plurality of evaporation chambers can be provided in the cylinder head, and a plurality of evaporation chambers can be provided in the cylinder block. Furthermore, the temperature sensor can be arranged at a location where the temperature reaches a high temperature inside the engine, that is, the temperature at which the refrigerant evaporates. An injection nozzle can be arranged by directing the injection port to such an arrangement location of the temperature sensor.

  In addition, the waste heat recovery apparatus of the present invention may be configured not to be overheated by the exhaust gas of the engine in the power recovery machine. FIG. 3 is an explanatory diagram showing a schematic configuration of an engine 40 incorporating another waste heat recovery apparatus 41 of the present invention. The waste heat recovery apparatus 41 has substantially the same configuration as the waste heat recovery apparatus 1 of the embodiment. However, the power recovery machine 19 of the waste heat recovery apparatus 1 includes a superheater 23, and the temperature of the steam collected in the superheater 23 is increased by the exhaust gas of the engine, whereas the power recovery machine of the waste heat recovery apparatus 41 42 differs from the superheater 23 in that a chamber 43 is disposed. In the waste heat recovery device 41, the steam generated in the cylinder block 4 and the cylinder head 5 is collected in the chamber 42, and then flows into the expander 24 to recover the waste heat. In addition, since the other structure is the same as Example 1, about the component same as Example 1, the same reference number is attached | subjected in drawing and the detailed description is abbreviate | omitted.

It is explanatory drawing which showed schematic structure of the waste heat recovery apparatus of Example 1. FIG. It is explanatory drawing which showed schematic structure of the waste heat recovery apparatus of Example 2. FIG. It is explanatory drawing which showed schematic structure of the other waste heat recovery apparatus of this invention.

Explanation of symbols

1, 31, 41 Waste heat recovery device 2, 32, 40 Engine 4, 34 Cylinder block 5, 35 Cylinder head 6, 7, 36 Water jacket 10a First injection nozzle 10b Second injection nozzle 10c Third injection nozzle 10d Fourth Injection nozzle 10e Fifth injection nozzle 10f Sixth injection nozzle 11 Refrigerant path 13a First temperature sensor 13b Second temperature sensor 13c Third temperature sensor 13d Fourth temperature sensor 13e Fifth temperature sensor 13f Sixth temperature sensor 15 ECU
16 recovery path 17a first steam path 17b second steam path 19, 42 power recovery machine 22 check valve 23 superheater 24 expander 25 generator 26 exhaust pipe 37 head gasket 43 chamber

Claims (7)

Two or more evaporation chambers that generate steam by the waste heat of the engine;
A power recovery machine that recovers waste heat of the engine through the steam generated in the evaporation chamber;
With
A waste heat recovery apparatus for an engine, wherein steam generated in each of the evaporation chambers is caused to flow into the power recovery machine. The engine waste heat recovery apparatus according to claim 1,
The waste heat recovery apparatus for an engine is characterized in that the evaporation chamber is provided at two or more places where the temperatures are different. The engine waste heat recovery apparatus according to claim 1,
The waste heat recovery apparatus for an engine, wherein the evaporation chamber is provided in a cylinder head and a cylinder block. The engine waste heat recovery apparatus according to claim 1,
A waste heat recovery device for an engine comprising a refrigerant flow suppressing means disposed between a cylinder head and a cylinder block. The engine waste heat recovery apparatus according to claim 1,
The power recovery machine includes a collecting portion where steam generated in each of the evaporation chambers collects;
An expander that operates by steam gathered in the gathering section;
An exhaust heat recovery device for an engine characterized by comprising: The engine waste heat recovery apparatus according to claim 1,
The power recovery machine includes a collecting portion where steam generated in each of the evaporation chambers collects;
An expander that operates by steam gathered at the gathering part,
The waste heat recovery device for an engine, wherein the collecting portion is arranged so that heat is transferred from an exhaust gas of the engine. The engine waste heat recovery apparatus according to claim 1,
An engine waste heat recovery apparatus comprising a check valve that blocks the flow of refrigerant from the power recovery machine toward the evaporation chamber.

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