JP2005300103A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of evaporating condensate, without blocking an exhaust gas passage. <P>SOLUTION: A plurality of gas tubes 4 is arranged inclinedly to a horizontal direction to make an inlet end cap part 2 side get lower than an outlet end cap 3 side in each thereof. A condensed water evaporation part 6 is set in a low position not to interfere with the plurality of gas tubes 4, in a lower part of an inlet end cap part 2. When the condensed water W is generated inside the gas tubes, the condensed water W flows down into the condensed water evaporation part 6 of the inlet end cap part 2 along on an inner face of the plurality of gas tubes 4 by a dead weight thereof, and is heated to be evaporated by a high temperature of exhaust gas G flowing from an exhaust gas flow-in inlet 2a into the inlet end cap part 2, in the evaporation part 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat exchanger, and more particularly to a heat exchanger for exchanging heat from exhaust gas of an internal combustion engine.

  2. Description of the Related Art Conventionally, in an internal combustion engine such as an engine, exhaust gas generated during combustion is cooled by a heat exchanger and released to the atmosphere. In such a heat exchanger for exhaust gas cooling, condensed water is generated in the exhaust gas passage during heat exchange or the like. For example, in the heat exchanger disclosed in Patent Document 1, a drain is formed at the bottom of the exhaust gas passage. A hole is formed, and condensed water generated in the exhaust gas passage is discharged from the drain hole to the outside.

JP 2000-39271 A

However, since such condensed water contains oil, sulfuric acid, etc., the condensed water discharged from the drain hole to the outside of the heat exchanger is subjected to oil separation and neutralization and discharged outside the machine. Therefore, it is necessary to provide a dedicated filter, a neutralization tank, and the like for this purpose, which not only requires these installation spaces but also increases costs.
Therefore, in recent years, a method has been proposed in which condensed water is evaporated in a heat exchanger without using a drain mechanism.

However, since the condensed water contains oil as described above, when the condensed water is evaporated in the heat exchanger, the oil contained in the condensed water is carbonized to generate tar-like deposits. As a result, the exhaust gas passage in the heat exchanger may be blocked.
The present invention has been made to solve such problems, and an object of the present invention is to provide a heat exchanger capable of evaporating condensed water and processing it without blocking an exhaust gas passage.

The heat exchanger according to the present invention is a heat exchanger that does not have a drain mechanism for circulating the exhaust gas of the internal combustion engine through the exhaust gas passage and exchanging heat and discharging condensed water generated in the exhaust gas passage to the outside. A condensed water evaporation part is set on one end side of the passage, and the exhaust gas passage is disposed obliquely or vertically with respect to the horizontal direction so that the condensed water evaporation part is at a low position, and the condensed water generated in the exhaust gas passage is exhaust gas passage Then, it flows down to the condensate evaporation part and is evaporated by the heat of the exhaust gas in this condensate evaporation part.
Condensed water generated in the exhaust gas passage flows along the inner surface of the exhaust gas passage due to its own weight and flows down to the condensed water evaporation section, where it is heated and evaporated by the high temperature exhaust gas.

  According to the present invention, the condensed water evaporation part is set on one end side of the exhaust gas passage, and the exhaust gas passage is disposed obliquely or vertically with respect to the horizontal direction so that the condensed water evaporation part is at a low position. The condensed water generated in the passage flows down to the condensed water evaporation section through the exhaust gas passage, and is evaporated by the heat of the exhaust gas in the condensed water evaporation section, so that the condensed water is evaporated without blocking the exhaust gas passage. Can be processed. Therefore, it is not necessary to provide a drain mechanism for discharging condensed water, a filter for purifying condensed water, a neutralization tank, and the like, thereby reducing costs and saving space.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
In FIG. 1, the whole structure of the heat exchanger which concerns on embodiment of this invention is shown. The heat exchanger 1 is used as a heat exchanger for exchanging heat of exhaust gas discharged from an engine in a gas heat pump (GHP) or the like to use this heat. An inlet end cap portion 2 and an outlet end cap portion 3 are disposed on both ends of the heat exchanger 1. Between the inlet end cap part 2 and the outlet end cap part 3, a plurality of gas tubes 4 are arranged in parallel and spaced apart from each other, and the inlet end cap part 2 and the outlet are arranged via the plurality of gas tubes 4. The end cap portion 3 communicates with each other. The inlet end cap portion 2, the outlet end cap portion 3, and the plurality of gas tubes 4 constitute an exhaust gas passage. The inlet end cap part 2 has an exhaust gas inlet 2a, and the outlet end cap part 3 has an exhaust gas outlet 3a. The plurality of gas tubes 4 are surrounded by a cooling unit 5, and the cooling unit 5 has a cooling fluid inlet and a cooling fluid outlet (not shown), and a low-temperature fluid such as water is supplied from the cooling fluid inlet to the cooling unit. 5 flows into the cooling section 5 and is discharged from the cooling fluid outlet.

  Here, the plurality of gas tubes 4 are arranged obliquely with respect to the horizontal direction such that the inlet end cap portion 2 side is lower than the outlet end cap portion 3 side. In addition, a condensed water evaporation unit 6 is set at a lower position below the inlet end cap unit 2 so as not to interfere with the plurality of gas tubes 4, and is generated inside the gas tube 4 or the like during heat exchange. The condensed water flows along the inner surface of the gas tube 4 and flows down to the condensed water evaporation section 6 of the inlet end cap section 2.

The condensed water evaporation section 6 has a volume that can sufficiently store deposits that may be generated by evaporation of condensed water during the use period of the heat exchanger 1.
Further, the exhaust gas G flowing into the inlet end cap portion 2 from the exhaust gas inlet 2a is at a high temperature of, for example, 200 ° C. or more, and has a sufficient amount of heat to evaporate the condensed water.

  Next, the operation of the heat exchanger 1 according to the embodiment of the present invention will be described. The high temperature exhaust gas G discharged from the engine first flows into the inlet end cap portion 2 from the exhaust gas inlet 2a, flows in the plurality of gas tubes 4, and the low temperature fluid in the cooling portion 5 in the tubes 4 After the heat exchange, the gas flows into the outlet end cap portion 3 and is discharged from the exhaust gas outlet 3a to the outside of the heat exchanger 1.

Here, when the exhaust gas G is heat-exchanged in the plurality of gas tubes 4, when the exhaust gas G is cooled to a temperature below the dew point, moisture contained in the exhaust gas G is condensed and condensed water W is formed. Although the plurality of gas tubes 4 are arranged obliquely such that the inlet end cap portion 2 side is lower than the outlet end cap portion 3 side, as shown by broken line arrows in FIG. The condensed water W flows along the inner surfaces of the plurality of gas tubes 4 due to its own weight and flows down to the condensed water evaporation section 6 of the inlet end cap section 2. In the condensed water evaporation section 6, the condensed water W is heated and evaporated by the high-temperature exhaust gas G flowing into the inlet end cap section 2 from the exhaust gas inlet 2 a.
Since the plurality of gas tubes 4 are in contact with the low-temperature fluid in the cooling unit 5, the condensed water W generated in the gas tube 4 is not evaporated in the tube 4, and the condensed water evaporation unit 6. And is evaporated in the condensed water evaporation section 6.

  During the evaporation, the oil contained in the condensed water may be carbonized to generate a tar-like deposit, but the condensed water evaporation unit 6 where the condensed water W is evaporated does not interfere with the plurality of gas tubes 4. Since it has a volume that can be set at such a low position and can sufficiently store the deposit, it is possible to prevent a problem that the gas tube 4 is blocked by the deposit. Therefore, it is possible to realize a heat exchanger capable of treating condensed water by evaporation without blocking the exhaust gas passage.

  In the above-described embodiment, the plurality of gas tubes 4 are arranged obliquely such that the inlet end cap portion 2 side is lower than the outlet end cap portion 3 side, and the condensed water evaporation portion is disposed in the inlet end cap portion 2. However, the present invention is not limited to this, and the exhaust gas G after heat exchange with a low-temperature fluid in the plurality of gas tubes 4 has a temperature sufficient to evaporate condensed water. In this case, the plurality of gas tubes 4 are arranged obliquely so that the outlet end cap portion 3 side is lower than the inlet end cap portion 2 side, and the condensed water evaporation portion 6 is set at the lower portion of the outlet end cap portion 3. You can also Even in such a configuration, the condensed water W generated in the gas tube 4 is led to the condensed water evaporation section 6 of the outlet end cap section 3 and is evaporated there, and the exhaust gas passage as in the embodiment. The condensed water can be evaporated and processed without clogging the water.

  Further, as shown in FIG. 2, a muffler 11 is connected to the exhaust gas outlet 3 a of the heat exchanger 1 of the above-described embodiment so as to be positioned above the heat exchanger 1. If the generated condensed water is configured to flow down to the condensed water evaporation section 6 of the heat exchanger 1, the condensed water of the muffler 11 can also be guided to the condensed water evaporation section 6 of the heat exchanger 1 and evaporated. As a result, it is not necessary to provide a condensate treatment drain mechanism or the like in the muffler 11, and costs can be reduced and space can be saved.

Further, in the above-described embodiment, as shown in FIG. 3, at least one heat transfer fin for efficiently taking in the heat of the exhaust gas G into the condensed water evaporation unit 6 at the lower part in the inlet end cap unit 2. If 12 is arrange | positioned, the condensed water W guide | induced to the condensed water evaporation part 6 can be evaporated effectively.
Further, as shown in FIG. 4, not only the plurality of gas tubes 4 but also the heat exchanger of the type in which the inlet end cap part 2 and the outlet end cap part 3 are surrounded by the cooling part 5 as described above. By using the heat fins 12, heat can be efficiently taken into the condensed water evaporation unit 6 and the condensed water W guided to the evaporation unit 6 can be evaporated and processed.

Further, as in the above-described embodiment, instead of arranging the plurality of gas tubes 4 obliquely with respect to the horizontal direction, the plurality of gas tubes 4 are arranged on the outlet end cap portion 3 side on the inlet end cap portion 2 side. The condensed water W flows down to the condensed water evaporation section 6 along the gas tube 4 and is evaporated by the evaporation section 6 even if it is arranged vertically so as to be lower than that of the embodiment. Can be obtained.
The present invention can be applied not only to the shell and tube type heat exchanger as in the above-described embodiment, but also to a multilayer type and other various heat exchangers.
The heat exchanger of the present invention can be widely used not only as a gas heat pump but also as a heat exchanger for exchanging heat from exhaust gas discharged from an internal combustion engine.

The angle at which the heat exchanger is inclined is not particularly limited, but if the condensed water flows backward to the exhaust gas inlet, the flow area of the exhaust gas passage is reduced by the condensed water, and the flow rate of exhaust gas that can pass through Therefore, it is preferable to set the angle so that the condensed water does not flow backward to the exhaust gas inlet. In addition, although the present invention can be applied to various heat exchangers, a heat exchanger in which exhaust gas is cooled to a relatively low temperature and a large amount of condensed water is generated, such as a heat exchanger of a gas heat pump. Since the amount of condensed water evaporates and becomes a larger amount, the effect of the present invention is also great.
Furthermore, the inlet end cap part is preferably formed in a rectangular shape as in the above-described embodiment, since the volume of the condensed water evaporation part can be increased. An entrance end cap portion may be used.

It is a schematic diagram which shows the heat exchanger which concerns on embodiment of this invention. It is a figure which shows a mode that the muffler was connected to the heat exchanger in embodiment. It is a model diagram which shows a mode that the fin was attached in the heat exchanger in embodiment. It is a model diagram which shows another heat exchanger in embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Heat exchanger, 2 Inlet end cap part, 2a Exhaust gas inlet, 3 Outlet end cap part, 3a Exhaust gas outlet, 4 Gas tube, 5 Cooling part, 6 Condensate evaporation part, 11 Muffler, 12 Fin, G Exhaust gas , W condensed water.

Claims (1)

In the heat exchanger that does not have a drain mechanism for discharging the condensed water generated in the exhaust gas passage while circulating the exhaust gas of the internal combustion engine through the exhaust gas passage and exchanging heat,
A condensed water evaporation part is set on one end side of the exhaust gas passage,
The exhaust gas passage is disposed obliquely or vertically with respect to the horizontal direction so that the condensed water evaporation section is at a low position,
The condensed water generated in the exhaust gas passage flows down to the condensed water evaporation section through the exhaust gas passage, and is evaporated by the heat of the exhaust gas in the condensed water evaporation section.

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