JP2013185469A - Heat recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat recovery device suppressing the shortage of a working fluid in a loop-like circulation passage.SOLUTION: A heat recovery device 1 includes: a boiler 11 for vaporizing a working fluid by the waste heat of an engine; a condenser 12 condensing the working fluid vaporized in the boiler 11; a steam passage 13 for supplying the working fluid vaporized in the boiler 11 to the condenser 12; a condensed water passage 14 which returns the working fluid condensed in the condenser 12 to the boiler 11, and forms a loop-like circulation passage together with the boiler; and a working fluid supply passage 16 which connects a reserver tank 15 storing the working fluid and a joint part 141 provided in the condensed water passage 14 to each other. In the vicinity of the joint part 141 of the condensed water passage 14 in the heat recovery device 1, the position Hof a first passage part 142 constituting a passage of the boiler 11 side from the joint part 141 in the gravity direction is higher than the position Hof a second passage part 143 constituting a passage of the condenser 12 side from the joint part 141 in the gravity direction.

Description

  The present invention relates to a heat recovery apparatus.

  2. Description of the Related Art Conventionally, there has been known a waste heat utilization device that collects and uses waste heat energy generated with the operation of an engine via a working fluid as a medium. One such waste heat utilization device is, for example, a boiling device that boils the working fluid with the heat of the exhaust gas of the engine, receives heat from the boiling working fluid, warms up the heating part, and operates A steam circulation type heat exchange device that collects waste heat and transports it by forming a flow path that connects a condenser that condenses the fluid in a loop and circulating the working fluid in the loop flow path is there. Patent Document 1 discloses an engine waste heat utilization device including a reservoir tank capable of supplying a working fluid to a boiling machine (corresponding to a “steam generator” in Patent Document 1).

JP 2010-156315 A

  In the waste heat utilization apparatus of Patent Document 1, the working fluid is supplied when the pressure in the boiling device decreases. In the configuration of Patent Document 1, when the working fluid is supplied from the reservoir tank, if the temperature of the boiling device is equal to or higher than the boiling point of the working fluid, the working fluid supplied to the boiling device is instantly vaporized and the internal pressure of the boiling device is increased. Soar. If the internal pressure of the boiling device rises too much, the flow path from the reservoir tank to the boiling device is blocked, and a necessary amount of working fluid cannot be supplied, resulting in a shortage of working fluid for heat transport.

  With respect to such a problem, it is possible to supply the working fluid to the boiling device by a pumping device such as a pump. However, since energy is used to drive a pumping device such as a pump, it is not efficient from the viewpoint of energy utilization efficiency.

  Then, in view of the said subject, this invention aims at providing the heat recovery apparatus which suppresses the shortage of the working fluid in a loop-shaped circulation path.

  The heat recovery apparatus of the present invention that solves such a problem includes a boiling device that vaporizes a working fluid by waste heat of an internal combustion engine, a condenser that condenses the working fluid vaporized in the boiling device, and an operation vaporized in the boiling device. A steam passage for supplying fluid to the condenser, and a condensed water passage for returning the working fluid condensed in the condenser to the boiling device and forming a loop-shaped circulation path together with the boiling device, the condenser and the steam passage And a working fluid supply passage that connects a reservoir tank that stores the working fluid and a merging portion provided in the condensed water passage, and in the vicinity of the merging portion of the condensate passage, the boiling unit is located near the merging portion. The height in the gravitational direction of the first passage portion constituting the passage on the side is higher than the height in the gravitational direction of the second passage portion constituting the passage on the condenser side from the merging portion.

  As a result, when the refrigerant is supplied from the reservoir tank to the condensed water passage, the supplied working fluid flows into the condenser side, so that rapid vaporization of the working fluid in the boiling device is suppressed, and the inside of the loop-shaped flow path is suppressed. The increase in pressure can be suppressed. As a result, it becomes possible to supply the required amount of working fluid from the reservoir tank into the circulation path, and the shortage of working fluid can be suppressed.

  The heat recovery apparatus may be provided with a valve for opening and closing the flow path in the working fluid supply passage. In the heat recovery apparatus, the position of the reservoir tank in the gravitational direction may be arranged to be higher than the position of the merging portion in the gravitational direction.

  The heat recovery apparatus of the present invention can suppress the shortage of working fluid in the loop-shaped circulation path.

It is the figure which showed schematic structure of the heat recovery apparatus of an Example. It is the figure which showed an example of the boiling machine. Fig.3 (a) is an enlarged view of the periphery of the confluence | merging part of a condensed water channel | path. FIG.3 (b) is an enlarged view of the confluence | merging part periphery of the condensed water channel | path of a comparative example. It is the figure which showed a mode that the working fluid was supplied in an Example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a heat recovery apparatus 10 of the present embodiment. The arrows in FIG. 1 indicate the direction in which the working fluid flows. The heat recovery device 10 is a device that recovers waste heat energy generated during operation of the engine (internal combustion engine) using a working fluid as an intermediate, and transports the heat to a warm-up request site that requires warm-up. The heat recovery device 10 recovers the thermal energy of the exhaust as waste heat energy. The heat recovery apparatus 10 includes a boiling device 11, a condenser 12, a steam passage 13, a condensed water passage 14, a reservoir tank 15, and a working fluid supply passage 16. Boiler 11, condenser 12, steam passage 13, and condensed water passage 14 form a loop-shaped circulation path, and the working fluid is circulated in the inside thereof.

  Boiler 11 vaporizes the working fluid by the waste heat of the engine. Boiler 11 is incorporated in an exhaust pipe 21 through which engine exhaust passes. FIG. 2 is a diagram showing an example of the boiling device 11. FIG. 2 shows a cross section when the boiling device 11 is viewed in the traveling direction of the exhaust gas. The boiling device 11 includes a boiling chamber 111 in which the working fluid boils (vaporizes) and a plurality of heat exchange tubes 112 that penetrate the boiling chamber 111. The heat exchange pipe 112 is connected to the exhaust pipe 21, and the exhaust passes through the heat exchange pipe 112. The heat exchange pipe 112 is narrower than the exhaust pipe 21 and is arranged with a gap through which the working fluid enters between adjacent heat exchange pipes 112. Heat is transferred from the exhaust inside the heat exchange pipe 112 configured in this way to the working fluid outside, and the working fluid that collects the heat energy of the exhaust boils (vaporizes).

  The condenser 12 is a heat exchanger provided in a part (warm-up requesting part) 22 that is required to warm up the engine. The warm-up request unit 22 includes, for example, a heater or a crank cap for indoor heating. In addition to this, the warm-up requesting unit 22 may be a part where the effect of reducing friction loss can be obtained by warming up. The condenser 12 transfers heat from the working fluid vaporized in the boiling device 11 to the warm-up request unit 22 and warms up the warm-up request unit 22. The working fluid in the condenser 12 condenses when transferring heat to the warm-up request unit 22 and returns to the liquid. In addition, it is more preferable that the condenser 12 is disposed at a higher position than the boiling device 11 so that the working fluid condensed by the condenser 12 is naturally conveyed to the boiling device 11 by gravity.

  The steam passage 13 is a pipe that communicates the boiler 11 and the condenser 12. The steam passage 13 is a heat transport path for supplying the working fluid vaporized in the boiling device 11 to the condenser 12. The condensed water passage 14 is a pipe that communicates the condenser 12 and the boiling device 11. The condensed water passage 14 is a passage for returning the working fluid condensed in the condenser 12 to the boiling device 11.

  Thus, in the heat recovery apparatus 10, a loop-shaped circulation path is formed by the boiling device 11, the condenser 12, the steam passage 13, and the condensed water passage 14, and the working fluid circulates while performing vaporization and condensation, The thermal energy recovered from the exhaust is transported to the warm-up request unit 22. The working fluid is selected in consideration of the temperature of the exhaust gas and the temperature of the warm-up request unit 22, and uses a fluid that boils at the temperature of the exhaust gas and condenses at the temperature of the warm-up request unit 22 at the time of the warm-up request. For example, water (steam) may be employed as the working fluid.

  The reservoir tank 15 is a reserve tank that stores the working fluid. The working fluid supply passage 16 is a pipe connecting the inside of the reservoir tank 15 and the condensed water passage 14. The working fluid supply passage 16 is connected to the condensed water passage 14 at the junction 141 of the condensed water passage 14. The working fluid supply passage 16 is provided with an opening / closing valve 17 that opens and closes the passage. The on-off valve 17 may be a pressure valve that opens and closes due to a pressure difference between both ends separated by the valve body. When the on-off valve 17 is opened, the working fluid in the reservoir tank 15 passes through the working fluid supply passage 16 and is supplied to the condensed water passage 14. The reservoir tank 15 may be arranged so that the position of the reservoir tank 15 in the gravity direction is higher than the position of the merge portion 141 in the gravity direction. In this case, the working fluid can be supplied to the condensed water passage 14 using gravity.

  Next, the condensed water passage 14 will be described in detail in comparison with a comparative example. FIG. 3A is an enlarged view of the periphery of the confluence portion 141 of the condensed water passage 14. FIG.3 (b) is an enlarged view of the confluence part 191 periphery of the condensed water channel | path of a comparative example. The arrows g in FIGS. 3 (a) and 3 (b) are directed downward in the direction of gravity, that is, in the direction of gravity. The apparatus of the comparative example has the same configuration as that of the present embodiment except for the configuration around the merging portion 191. The same configuration as that of the present embodiment will be described using the same reference numerals. As shown in FIGS. 3A and 3B, together with the present embodiment and the comparative example, the condensed water passage 14 (19) is connected to the first passage portion 142 (192) and the second passage with the junction portion 141 (191) as a boundary. It is divided into a passage portion 143 (193). The 1st channel | path part 142 (192) comprises the channel | path by the side of the boiler 11 from the confluence | merging part 141 (191). The 2nd channel | path part 143 (193) comprises the channel | path by the side of the condenser 12 from the confluence | merging part 141 (191).

In this embodiment, as shown in FIG. 3 (a), in the vicinity of the merging portion 141, the position _{H 1} in the gravity direction of the first passage portion 142 is higher than the position of _{H 2} gravitational direction of the second passage portion 143. In other words, the first passage portion 142 is provided at a position higher in the direction of gravity than the second passage portion 143. Each of the first passage portion 142 and the second passage portion 143 may be a single pipe, or may be a single pipe formed integrally. On the other hand, in the comparative example, as shown in FIG. 3B, the heights in the gravity direction of the first passage portion 192 and the second passage portion 193 are equal in the vicinity of the merge portion 191.

  The difference between the configuration in the vicinity of the merging portion 141 of the present embodiment and the configuration in the vicinity of the merging portion 191 of the comparative example affects when supplying the working fluid from the reservoir tank 15. Next, the difference between the embodiment and the comparative example when the working fluid is supplied from the reservoir tank 15 to the condensed water passage 14 will be described. FIG. 4 is a diagram showing how the working fluid is supplied in this embodiment.

  In the configuration of the comparative example, the height in the gravity direction of the first passage portion 192 and the second passage portion 193 is equal in the vicinity of the merge portion 191. For this reason, when working fluid is supplied from the working fluid supply passage 16, the flow path through which the working fluid flows is determined by the relationship between the pressure of the first passage portion 192 and the second passage portion 193. In a state where the liquid working fluid is depleted in the boiling device 11, the pressure in the boiling device 11 is low, and the working fluid supplied to the merging portion 191 flows into the first passage portion 192. As a result, the working fluid supplied to the boiling device 11 is vaporized, and the internal pressure of the condensed water passage 14 rapidly increases. In this case, the supply of the working fluid from the reservoir tank 15 may be hindered and the supply of the working fluid may be insufficient.

In the configuration of this embodiment, in the vicinity of the merging portion 141, the position H ₁ in the gravity direction of the first passage portion 142 is higher than the position of H ₂ gravitational direction of the second passage portion 143. For this reason, when the working fluid is supplied from the working fluid supply passage 16 side, the working fluid flows into the second passage portion 143 located on the lower side in the gravity direction according to gravity (FIG. 4A). When the second passage portion 143 is filled with the working fluid and the liquid level rises, the working fluid flows into the first passage portion 142 located above the second passage portion 143 in the gravity direction (FIG. 4B). A working fluid is supplied to the boiling device 11.

  Thus, when the refrigerant is supplied from the reservoir tank 15 to the condensed water passage 14, the supplied working fluid flows into the second passage portion 143 on the condenser 12 side, and the working fluid corresponding to the volume of the second passage portion 143 is generated. Stored. Thereby, even when the working fluid cannot be temporarily supplied from the reservoir tank 15, there is no shortage of working fluid in the circulation path. Thereby, the heat recovery apparatus 10 can transport the heat recovered from the exhaust to the warm-up request unit 22 and effectively use it.

  The heat recovery device 10 can supply a working fluid without using a pumping device such as a pump, and can have a piping configuration that is as compact as possible.

  Further, for example, when the working fluid supplied from the reservoir tank 15 is supplied to the vapor passage 13, it is conceivable that the flow of the vaporized working fluid is hindered. However, if the working fluid is supplied to the condensed water passage 14 as in the present embodiment, there is no fear of hindering the flow of the vaporized working fluid. Further, since the condensed water passage 14 and the reservoir tank 15 are connected by the working fluid supply passage 16, the condensed working fluid increases, and even when the volume of the condensed water passage 14 is exceeded, the increased working fluid is reduced. It can be collected in the reservoir tank 15.

  As described above, according to the present embodiment, the heat recovery apparatus 10 includes the boiling device 11 that vaporizes the working fluid by the waste heat of the engine, the condenser 12 that condenses the working fluid vaporized in the boiling device 11, and the vaporization in the boiling device 11. The steam passage 13 for supplying the working fluid to the condenser 12 and the condensed water passage 14 for returning the working fluid condensed in the condenser 12 to the boiling device 11 form a loop-shaped circulation path. Furthermore, the heat recovery apparatus 10 includes a working fluid supply passage 16 that supplies the working fluid from a reservoir tank 15 that stores the working fluid to a junction 141 provided in the condensed water passage 14. In the vicinity of the confluence portion 141 of the condensed water passage 14, the position in the gravitational direction of the first passage portion 142 constituting the passage on the boiling device 11 side from the confluence portion 141 constitutes the passage on the condenser 12 side from the confluence portion 141. Higher than the position of the second passage portion 143 in the direction of gravity. Thereby, the heat recovery apparatus can suppress the shortage of the working fluid in the loop-shaped circulation path, and can recover and effectively use the waste heat.

  In addition, the heat recovery apparatus 10 can adjust the amount of the working fluid in the loop-shaped circulation path by providing the working fluid supply passage 16 with the on-off valve 17 that opens and closes the flow path. Further, it is possible to supply the working fluid to the circulation path when necessary.

  Further, in the heat recovery apparatus 10, by arranging the reservoir tank 15 so that the position of the reservoir tank 15 in the gravitational direction is higher than the position of the confluence portion 141 of the condensed water passage 14 in the gravitational direction, the working fluid is caused by gravity. It is possible to supply. As a result, energy used for supplying the working fluid can be reduced, so that fuel efficiency can be improved.

  In the heat recovery apparatus 10 described in the embodiment, a working fluid supply pump may be provided on the working fluid supply passage 16 between the reservoir tank 15 and the on-off valve 17. Further, the waste heat energy is not limited to the exhaust heat, and the waste heat may be recovered from cooling water that cools and raises the temperature of the engine cylinder head and cylinder block.

  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.

DESCRIPTION OF SYMBOLS 10 Heat recovery apparatus 11 Boiler 12 Condenser 13 Steam passage 14 Condensate passage 141 Confluence part 142 1st passage part 143 2nd passage part 15 Reservoir tank 16 Working fluid supply passage 17 On-off valve

Claims (3)

A boiler that vaporizes the working fluid by waste heat of the internal combustion engine;
A condenser for condensing the working fluid vaporized in the boiling device;
A steam passage for supplying the working fluid vaporized in the boiler to the condenser;
A working water condensed in the condenser is returned to the boiling device, and a condensed water passage that forms a loop-shaped circulation path together with the boiling device, the condenser, and the vapor passage;
A working fluid supply passage that connects a reservoir tank that stores the working fluid and a merging portion provided in the condensed water passage;
With
In the vicinity of the confluence portion of the condensed water passage, the position in the gravitational direction of the first passage portion constituting the passage on the boiling side from the confluence portion is the second position constituting the passage on the condenser side from the confluence portion. A heat recovery device characterized by being higher than the position of the passage portion in the direction of gravity.   The heat recovery apparatus according to claim 1, wherein a valve for opening and closing the flow path is provided in the working fluid supply passage.   The heat recovery apparatus according to claim 1 or 2, wherein a position of the reservoir tank in the gravity direction is higher than a position of the merging portion in the gravity direction.

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