JP4821816B2 - Exhaust heat recovery unit - Google Patents

Exhaust heat recovery unit Download PDF

Info

Publication number
JP4821816B2
JP4821816B2 JP2008191972A JP2008191972A JP4821816B2 JP 4821816 B2 JP4821816 B2 JP 4821816B2 JP 2008191972 A JP2008191972 A JP 2008191972A JP 2008191972 A JP2008191972 A JP 2008191972A JP 4821816 B2 JP4821816 B2 JP 4821816B2
Authority
JP
Japan
Prior art keywords
exhaust gas
exhaust
heat recovery
flow path
inner cylinder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2008191972A
Other languages
Japanese (ja)
Other versions
JP2010031671A (en
Inventor
高晴 永利
正克 坪内
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp filed Critical Toyota Motor Corp
Priority to JP2008191972A priority Critical patent/JP4821816B2/en
Publication of JP2010031671A publication Critical patent/JP2010031671A/en
Application granted granted Critical
Publication of JP4821816B2 publication Critical patent/JP4821816B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Landscapes

  • Exhaust Silencers (AREA)

Description

本発明は、内燃機関の排気ガスの熱を回収するための排気熱回収器に関する。特に、排気熱回収器の内部に発生する凝縮水を排出する技術に関する。   The present invention relates to an exhaust heat recovery device for recovering heat of exhaust gas of an internal combustion engine. In particular, the present invention relates to a technique for discharging condensed water generated inside an exhaust heat recovery unit.

従来より、自動車用エンジンの排気ガスの熱を回収する機器として、排気熱回収器が知られている。このような排気熱回収器は、内燃機関の排気管の途中に設置され、排気管を通過するエンジンの排気ガスとエンジンの冷却水との間で熱交換を行う。エンジンの冷却水を介して回収された排気熱は、例えば、車室内の暖房に利用される。また、エンジンの暖機運転を早期に完了させるために、エンジンの冷間時（例えばエンジンの始動初期時）に冷却水温度を急速に上昇させることにも利用される。   Conventionally, an exhaust heat recovery device is known as a device for recovering the heat of exhaust gas from an automobile engine. Such an exhaust heat recovery device is installed in the middle of the exhaust pipe of the internal combustion engine, and performs heat exchange between the exhaust gas of the engine passing through the exhaust pipe and the cooling water of the engine. The exhaust heat recovered via the engine coolant is used for heating the passenger compartment, for example. Moreover, in order to complete the warm-up operation of the engine at an early stage, it is also used to rapidly increase the coolant temperature when the engine is cold (for example, at the initial start of the engine).

このような排気熱回収器には、内部の排気ガスの流路が切替可能となったものが多い。特許文献１に開示されている排気熱回収器は、熱交換部を避けて排気ガスを通過させるバイパス流路を形成する内筒部と、この内筒部の下流側でパイパス流路開閉するバルブと、内筒部の外周側に間隔をおいて設けられた外筒部と、内筒部と外筒部の間に設けられた熱交換部（排気熱回収流路および冷却水流路）とを備えている。排気熱回収を行う場合には、バルブを閉鎖し、内筒部内に導入された排気ガスを、内筒部の側部に設けられた多数の小孔より、内筒部の外周に設けられた排気熱回収流路に導入し、冷却水流路を流れる冷却水との間で熱交換を行わせる。   Many of such exhaust heat recovery devices are capable of switching the flow path of the internal exhaust gas. An exhaust heat recovery device disclosed in Patent Document 1 includes an inner cylinder part that forms a bypass channel that allows exhaust gas to pass through avoiding a heat exchange part, and a valve that opens and closes a bypass channel on the downstream side of the inner cylinder part And an outer cylinder part provided at an interval on the outer peripheral side of the inner cylinder part, and a heat exchange part (exhaust heat recovery flow path and cooling water flow path) provided between the inner cylinder part and the outer cylinder part. I have. When exhaust heat recovery is performed, the valve is closed, and the exhaust gas introduced into the inner cylinder part is provided on the outer periphery of the inner cylinder part through a number of small holes provided in the side part of the inner cylinder part. The heat is introduced into the exhaust heat recovery passage and exchanged with the cooling water flowing through the cooling water passage.

一方、排気熱回収を行わない場合には、バルブを開放して内筒部内に導入された排気ガスをストレートに下流側に排出して、排気ガスを熱交換部に導入しないようにし、必要以上の冷却水の温度上昇を抑制するとともに、排気ガスの圧損を抑制する。   On the other hand, when exhaust heat recovery is not performed, open the valve and exhaust the exhaust gas introduced into the inner cylinder part straight downstream, so that the exhaust gas is not introduced into the heat exchange part. The temperature rise of the cooling water is suppressed, and the pressure loss of the exhaust gas is suppressed.

ところで、排気ガスの主成分には、窒素、二酸化炭素および水が多量に含まれており、排気熱回収器においては、排気ガスが熱交換で温度降下するのに伴い多くの凝縮水が発生する。この凝縮水は、アイドリング時など排気ガス流速が小さい状況が続くと排出されずに器内に滞留し易くなる。凝縮水は、液体のまま器外下流側へ排出されれば問題ないが、排気熱回収器内で蒸発すると、その際に周囲の熱を奪うため、熱回収効率が低下するという問題が生じる。また、滞留凝縮水が腐食性であったり、寒冷時に凍結すると、排気熱回収器各部に悪影響を及ぼすおそれがある。   By the way, the main components of the exhaust gas contain a large amount of nitrogen, carbon dioxide, and water, and in the exhaust heat recovery device, a lot of condensed water is generated as the temperature of the exhaust gas decreases due to heat exchange. . This condensed water is likely to stay in the vessel without being discharged when the exhaust gas flow rate is low, such as during idling. There is no problem if the condensed water is discharged to the downstream side outside the vessel as a liquid, but if it is evaporated in the exhaust heat recovery device, the surrounding heat is taken away at that time, causing a problem that the heat recovery efficiency is lowered. In addition, if the accumulated condensed water is corrosive or frozen when it is cold, it may adversely affect each part of the exhaust heat recovery unit.

特許文献１に開示されている排気熱回収器は、凝縮水を器外へ排出し易くするために、外筒部の下流側にテーパ部を設け、テーパ部の大径端の最下部を同テーパ部の小径端の最下部より高位置とし、さらに外筒部を下流側へ傾斜させている。これにより、排気熱回収器の外筒部内に発生した凝縮水を排気ガス流によって器外へ排出し易くし、排気熱回収器内での凝縮水の滞留を防止している。   The exhaust heat recovery device disclosed in Patent Document 1 is provided with a tapered portion on the downstream side of the outer cylinder portion so that the condensed water can be easily discharged outside the device, and the lowermost portion of the large diameter end of the tapered portion is the same. The position is higher than the lowermost end of the small diameter end of the tapered portion, and the outer cylinder portion is further inclined to the downstream side. Thereby, the condensed water generated in the outer cylinder part of the exhaust heat recovery device is easily discharged out of the device by the exhaust gas flow, and the condensate water stays in the exhaust heat recovery device.

ところで、本件出願人は、本件発明に係る排気熱回収器を完成する以前に、図９に示すような、排気熱回収器１００を開発している。この排気熱回収器１００は、内筒部１１０と外筒部１２０との間に熱回収用の排気ガス流路１３１，１３２が同心状に二重に設けられている。この排気熱回収器１００では、バルブ１４０が閉鎖されると、内筒部１１０内に導入される排気ガスは、内筒部１１０の下流側開口部１１０ａに近い部分に形成された連通孔１１１から内側の排気ガス流路１３１に導入され、排気系上流側（図中左側）へ誘導される。このとき、排気ガス流路１３１を流れる排気ガスと内側の冷却水流路１３３を流れる冷却水との間で熱交換が行われる。内側の排気ガス流路１３１と外側の排気ガス流路１３２とは排気系上流側で連通しており、内側の排気ガス流路１３１内を排気系上流側に向かって流れる排気ガスはこの連通部で反転して外側の排気ガス流路１３２内を排気系下流側に向かって流れる。このとき、外側の排気ガス流路１３２内を流れる排気ガスと内側および外側の冷却水流路１３３，１３４を流れる冷却水との間で熱交換が行われる。
特開２００６−５５８０８４号公報 By the way, the present applicant has developed an exhaust heat recovery device 100 as shown in FIG. 9 before completing the exhaust heat recovery device according to the present invention. In the exhaust heat recovery device 100, exhaust gas flow paths 131 and 132 for heat recovery are provided concentrically and doublely between the inner cylinder portion 110 and the outer cylinder portion 120. In the exhaust heat recovery device 100, when the valve 140 is closed, the exhaust gas introduced into the inner cylinder portion 110 is communicated from a communication hole 111 formed in a portion near the downstream opening 110a of the inner cylinder portion 110. It is introduced into the inner exhaust gas passage 131 and guided to the exhaust system upstream side (left side in the figure). At this time, heat exchange is performed between the exhaust gas flowing through the exhaust gas passage 131 and the cooling water flowing through the inner cooling water passage 133. The inner exhaust gas passage 131 and the outer exhaust gas passage 132 communicate with each other on the upstream side of the exhaust system, and the exhaust gas flowing in the inner exhaust gas passage 131 toward the upstream side of the exhaust system is connected to this communication portion. And flows in the outer exhaust gas flow path 132 toward the downstream side of the exhaust system. At this time, heat exchange is performed between the exhaust gas flowing in the outer exhaust gas passage 132 and the cooling water flowing in the inner and outer cooling water passages 133 and 134.
JP 2006-558084 A

ところで、特許文献１に開示されている排気熱回収器のように、内筒部と外筒部との間に熱交換部が設けられ、内筒部内の排気ガス流路をバルブにて開閉することにより、内筒部内を流れる排気ガスを熱交換部に切替可能に導入する排気熱回収器では、エンジン始動直後に、低温の内筒部内で凝縮水が発生することがある。エンジン始動直後は、暖機運転が完了していないため、バルブが閉鎖していることが多く、内筒部内に発生した凝縮水を器外へ排出することができなかった。このため、バルブが開放するまでの間に内筒部内に発生した凝縮水が蒸発し熱回収効率が低下するおそれがあった。   Incidentally, as in the exhaust heat recovery device disclosed in Patent Document 1, a heat exchanging portion is provided between the inner cylinder portion and the outer cylinder portion, and the exhaust gas flow path in the inner cylinder portion is opened and closed by a valve. As a result, in the exhaust heat recovery device that introduces the exhaust gas flowing in the inner cylinder portion to the heat exchange portion in a switchable manner, condensed water may be generated in the low temperature inner cylinder portion immediately after the engine is started. Immediately after the engine was started, since the warm-up operation was not completed, the valve was often closed, and the condensed water generated in the inner cylinder part could not be discharged out of the vessel. For this reason, the condensed water generated in the inner cylinder part before the valve is opened may evaporate and the heat recovery efficiency may be lowered.

また、内筒部と外筒部との間に排気ガス流路が同心状に二重に設けられた排気熱回収器では、熱回収効率が向上する反面、内側の排気ガス流路に発生した凝縮水を器外へ排出しにくいという問題があった。   In addition, in the exhaust heat recovery device in which the exhaust gas flow path is provided concentrically and doublely between the inner cylinder part and the outer cylinder part, the heat recovery efficiency is improved, but it is generated in the inner exhaust gas flow path. There was a problem that it was difficult to discharge condensed water outside the vessel.

本発明は上記問題点に鑑みて創案されたものであり、内筒部と外筒部との間に排気ガス流路が同心状に多重に設けられた排気熱回収器において、内筒部内で発生する凝縮水をバルブの開閉状態にかかわらず内筒部内から器外へ排出することを可能とした排気熱回収器を提供することを目的とする。また、内側の排気ガス流路に発生した凝縮水を器外へ排出することを可能とした排気熱回収器を提供することをも目的とする。   The present invention has been devised in view of the above problems, and in an exhaust heat recovery device in which exhaust gas passages are provided concentrically and multiply between an inner tube portion and an outer tube portion, An object of the present invention is to provide an exhaust heat recovery device capable of discharging the generated condensed water from the inside of the inner cylinder portion to the outside of the device regardless of the open / closed state of the valve. It is another object of the present invention to provide an exhaust heat recovery device capable of discharging condensed water generated in an inner exhaust gas flow path to the outside.

上述の課題を解決するための手段として、本発明の排気熱回収器は、以下のように構成されている。すなわち、本発明の排気熱回収器は、側部に連通路を有する内筒部と、前記連通路より排気系下流側で前記内筒部内の排気ガス流路を開閉するバルブと、前記内筒部の外周側に間隔をおいて設けられた外筒部と、前記内筒部と前記外筒部との間に設けられた熱交換部と、を備えることを前提とするものであって、前記熱交換部は、前記内筒部の連通路より流出する排気ガスを排気系上流側へ誘導する第１排気ガス流路と、前記第１排気ガス流路の排気系上流側端部に連通され、前記第１排気ガス流路から導入される排気ガスを前記第１排気ガス流路の外周側で排気系下流側へ誘導する第２排気ガス流路と、前記第１排気ガス流路および前記第２排気ガス流路を通過する排気ガスと熱交換可能に冷媒を循環させる冷媒流路と、を備える。そして、前記第１排気ガス流路と、前記内筒部および前記熱交換部の排気ガス排出口より排出される排気ガスの排出エリアとを連通する第１凝縮水排出路が設けられたことを特徴としている。   As means for solving the above-described problems, the exhaust heat recovery device of the present invention is configured as follows. That is, the exhaust heat recovery device of the present invention includes an inner cylinder portion having a communication passage on a side portion, a valve for opening and closing an exhaust gas passage in the inner cylinder portion on the exhaust system downstream side from the communication passage, and the inner cylinder It is assumed that the outer cylinder part provided at intervals on the outer peripheral side of the part, and the heat exchange part provided between the inner cylinder part and the outer cylinder part, The heat exchanging portion communicates with a first exhaust gas passage that guides exhaust gas flowing out from the communication passage of the inner cylinder portion to the upstream side of the exhaust system, and an exhaust system upstream end portion of the first exhaust gas passage. A second exhaust gas passage for guiding the exhaust gas introduced from the first exhaust gas passage to the downstream side of the exhaust system on the outer peripheral side of the first exhaust gas passage; the first exhaust gas passage; A refrigerant flow path that circulates the refrigerant so as to exchange heat with the exhaust gas passing through the second exhaust gas flow path. And the 1st condensed-gas discharge path which connects the said 1st exhaust gas flow path and the exhaust area of the exhaust gas discharged | emitted from the exhaust pipe exhaust port of the said inner cylinder part and the said heat exchange part was provided. It is a feature.

かかる構成を備える排気熱回収器によれば、第１排気ガス流路と、排気ガスの排出エリアとを連通する第１凝縮水排出路が設けられていることから、第１排気ガス流路に発生した凝縮水を器外へ容易に排出することが可能となる。   According to the exhaust heat recovery device having such a configuration, the first exhaust gas passage is provided with the first condensed water discharge passage that communicates the first exhaust gas passage and the exhaust gas discharge area. The generated condensed water can be easily discharged out of the vessel.

また、本発明の排気熱回収器は、以下のように構成されていてもよい。すなわち、本発明の排気熱回収器は、上記構成を備える排気熱回収器において、前記第１排気ガス流路の外側壁面の下部に前記第１凝縮水排出路の入口に向かって下降傾斜した傾斜部が形成されていることを特徴とするものである。   Moreover, the exhaust heat recovery device of the present invention may be configured as follows. That is, the exhaust heat recovery device according to the present invention is an exhaust heat recovery device having the above-described configuration, wherein the exhaust heat recovery device is inclined downward toward the inlet of the first condensed water discharge passage at the lower portion of the outer wall surface of the first exhaust gas flow passage. A portion is formed.

かかる構成を備える排気熱回収器によれば、上記傾斜部が設けられていることから第１排気ガス流路内に発生した凝縮水は傾斜部によって第１凝縮水排出路の入口へ向かって流れ易くなる。その結果、より効率的に第１排気ガス流路内に発生した凝縮水を排気ガスの排出エリアを通じて器外へ排出することが可能となる。   According to the exhaust heat recovery device having such a configuration, since the inclined portion is provided, the condensed water generated in the first exhaust gas passage flows toward the inlet of the first condensed water discharge passage by the inclined portion. It becomes easy. As a result, the condensed water generated in the first exhaust gas flow path can be discharged more efficiently through the exhaust gas discharge area.

また、本発明の排気熱回収器は、以下のように構成されていてもよい。すなわち、本発明の排気熱回収器は、上記何れかの構成を備える排気熱回収器において、前記内筒部の排気系下流側端部の下部に、前記排気ガスの排出エリアへ連通する第２凝縮水排出路が設けられたことを特徴とするものである。   Moreover, the exhaust heat recovery device of the present invention may be configured as follows. That is, the exhaust heat recovery device according to the present invention is the exhaust heat recovery device having any one of the above-described configurations, and is connected to the exhaust gas discharge area at the lower part of the exhaust system downstream end of the inner cylinder portion. A condensed water discharge passage is provided.

かかる構成を備える排気熱回収器によれば、上記第２凝縮水排出路が設けられていることから、内筒部内で発生する凝縮水をバルブの開閉状態にかかわらず内筒部内から排気ガスの排出エリアを通じて器外へ容易に排出することが可能となる。   According to the exhaust heat recovery device having such a configuration, since the second condensate discharge path is provided, the condensate generated in the inner cylinder portion is discharged from the inner cylinder portion regardless of whether the valve is opened or closed. It can be easily discharged out of the vessel through the discharge area.

本発明に係る排気熱回収器によれば、内側の排気ガス流路（第１排気ガス流路）に発生した凝縮水を器外へ容易に排出することが可能となる。また、内筒部内で発生する凝縮水をバルブの開閉状態にかかわらず内筒部内から器外へ容易に排出することが可能となる。   According to the exhaust heat recovery device of the present invention, the condensed water generated in the inner exhaust gas passage (first exhaust gas passage) can be easily discharged outside the device. Further, the condensed water generated in the inner cylinder part can be easily discharged from the inner cylinder part to the outside regardless of the open / closed state of the valve.

以下、本発明の実施の形態について図面を参照して説明する。図１〜図５は本発明の実施の形態における、排気熱回収器１を示している。この排気熱回収器１は、例えば自動車のエンジンなどの排気系の一部を構成するものとして設置される。図１は排気熱回収器１の側面図、図２は排気熱回収器１の平面図、図３は図１のＡ−Ａ断面図、図４は排気熱回収器１の縦断面図、図５は図４のＢ矢視図である。   Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 show an exhaust heat recovery device 1 according to an embodiment of the present invention. The exhaust heat recovery device 1 is installed as a part of an exhaust system such as an automobile engine. 1 is a side view of the exhaust heat recovery device 1, FIG. 2 is a plan view of the exhaust heat recovery device 1, FIG. 3 is a cross-sectional view taken along the line AA in FIG. 5 is a view taken in the direction of arrow B in FIG.

排気熱回収器１は、内筒部１０、バルブ２０、熱交換部３０、外筒部４０などで主に構成されている。   The exhaust heat recovery device 1 is mainly composed of an inner cylinder part 10, a valve 20, a heat exchange part 30, an outer cylinder part 40, and the like.

内筒部１０は、内側に配置された第１内筒部１１と、この第１内筒部１１の外側に断熱材１３および所定の隙間を介して同心配置された第２内筒部１２とからなる２重管構造となっている。第１内筒部１１の上流側端部（図４中左側端部）は、第２内筒部１２の上流側端部より更に上流側に位置し、第２内筒部１２の下流側端部（図４中右側端部）は、第１内筒部１１の下流側端部より更に下流側に位置している。   The inner cylinder part 10 includes a first inner cylinder part 11 arranged on the inner side, and a second inner cylinder part 12 arranged concentrically on the outer side of the first inner cylinder part 11 via a heat insulating material 13 and a predetermined gap. It has a double pipe structure. The upstream end portion (left end portion in FIG. 4) of the first inner cylinder portion 11 is located further upstream than the upstream end portion of the second inner cylinder portion 12, and the downstream end of the second inner cylinder portion 12. The portion (the right end portion in FIG. 4) is located further downstream than the downstream end portion of the first inner cylinder portion 11.

第１内筒部１１の上流側端部には、排気系上流側の構成部材に接続され、同構成部材より排気ガスが導入される排気ガス導入口１１ａが形成されている。第２内筒部１２の側部には、第２内筒部１２の内外空間を連通する連通孔１２ａが形成されている。この連通孔１２ａは、第２内筒部１２内の排気ガスを後述する熱回収排気ガス流路３２ａへ導入するための連通路として機能する。また、第２内筒部１２の下流側端部の開口部（排気ガス排出口）１２ｂには、バルブ受座１２ｃが形成されている。図５に示すように、このバルブ受座１２ｃの下部（周方向最低位置）に内筒部１０の長手方向に沿った切欠が設けられており、この切欠によって内筒部１０内と排気ガス排出エリアＺとを連通する凝縮水排出路１４（第２凝縮水排出路）が形成されている。なお、上記排気ガス排出エリアＺは、内筒部１０や熱交換部３０の排気ガス排出口Ｅより排気ガスが排出されるエリアである。また、凝縮水排出路１４の形状は、内筒部１０内と排気ガス排出エリアＺとを連通するものであればよい。したがって、例えば、内筒部１０の長手方向に対して傾斜したものや、屈曲、湾曲したもの等であってもよい。   An exhaust gas introduction port 11a is formed at the upstream end of the first inner cylinder portion 11 and is connected to a component member on the upstream side of the exhaust system and into which exhaust gas is introduced from the component member. A communication hole 12 a that communicates the inner and outer spaces of the second inner cylinder portion 12 is formed in the side portion of the second inner cylinder portion 12. The communication hole 12a functions as a communication path for introducing the exhaust gas in the second inner cylinder portion 12 into a heat recovery exhaust gas passage 32a described later. A valve seat 12c is formed in the opening (exhaust gas discharge port) 12b at the downstream end of the second inner cylinder portion 12. As shown in FIG. 5, a notch along the longitudinal direction of the inner cylinder part 10 is provided in the lower part (the circumferential minimum position) of the valve seat 12c. A condensed water discharge path 14 (second condensed water discharge path) communicating with the area Z is formed. The exhaust gas discharge area Z is an area where exhaust gas is discharged from the exhaust gas discharge port E of the inner cylinder part 10 or the heat exchange part 30. Moreover, the shape of the condensed water discharge path 14 should just be what connects the inside cylinder part 10 and the exhaust gas discharge area Z. As shown in FIG. Therefore, for example, it may be inclined with respect to the longitudinal direction of the inner cylinder part 10, or may be bent or curved.

バルブ２０は、上記バルブ受座１２ｃに嵌脱自在に嵌まり込むように設けられており、内筒部１０の下流側端部の開口部１２ｂを開閉することによって、内筒部１０内の排気ガス流路を開閉する。なお、内筒部１０内の排気ガス流路を開閉するバルブは上記に限定されず種々のバルブを用いることができる。また、バルブ２０又は種々のバルブによって排気ガス流路を開閉する内筒部１０内の位置は、上記連通孔１２ａより下流側であればよい。   The valve 20 is provided so as to be detachably fitted into the valve seat 12c. By opening and closing the opening 12b at the downstream end portion of the inner cylinder part 10, the exhaust in the inner cylinder part 10 is provided. Open and close the gas flow path. The valve that opens and closes the exhaust gas passage in the inner cylinder portion 10 is not limited to the above, and various valves can be used. Moreover, the position in the inner cylinder part 10 which opens and closes an exhaust gas flow path with the valve | bulb 20 or various valves should just be a downstream from the said communicating hole 12a.

図３に示すように、バルブ２０の一側部は、バルブシャフト５１にビスなどの固定具５２にて固定されており、バルブシャフト５１が正逆方向へ回転されることにより、バルブ２０は外筒部４０内で開閉動作を行うようになっている。   As shown in FIG. 3, one side of the valve 20 is fixed to the valve shaft 51 with a fixing tool 52 such as a screw, and the valve 20 is externally rotated by rotating the valve shaft 51 in the forward and reverse directions. An opening / closing operation is performed in the cylindrical portion 40.

バルブシャフト５１は、その一端側が斜め下方に向かって外筒部４０を内側から外側に向かって貫通している。外筒部４０には、その内方に向かってくびれたくびれ部４０Ａが形成されており、バルブシャフト５１は、そのくびれ部４０Ａ，４０Ａの間に架設されたシャフトケース５３内に収容されている。バルブシャフト５１はシャフトケース５３内の両端付近に固定された軸受５４，５４，５５に回転自在に支持されている。なお、シャフトケース５３も外筒部４０を貫通している。このシャフトケース５３の中間部には、バルブ２０の可動領域を確保するための窓部５３ａが形成されている。   One end side of the valve shaft 51 penetrates the outer cylinder part 40 from the inner side toward the outer side in a diagonally downward direction. The outer cylinder portion 40 is formed with a constricted portion 40A constricted toward the inside thereof, and the valve shaft 51 is accommodated in a shaft case 53 erected between the constricted portions 40A and 40A. . The valve shaft 51 is rotatably supported by bearings 54, 54, 55 fixed near both ends in the shaft case 53. The shaft case 53 also passes through the outer cylinder portion 40. A window portion 53 a for securing a movable region of the valve 20 is formed at an intermediate portion of the shaft case 53.

軸受５４，５４の間には、排気ガスの漏出を抑えるラビリンス５６が嵌め込み装着されている。一方、シャフトケース５３の斜め上方の開口は、密閉キャップ５８により密閉され、排気ガスが外筒部４０から上記開口を通じて外へ漏出しないようになっている。   A labyrinth 56 that suppresses leakage of exhaust gas is fitted between the bearings 54 and 54. On the other hand, the obliquely upper opening of the shaft case 53 is sealed by a sealing cap 58 so that the exhaust gas does not leak out from the outer cylinder portion 40 through the opening.

シャフトケース５３およびバルブシャフト５１の斜め下端側の周囲には、バルブシャフト５１を、バルブ２０が閉塞する方向へ回転付勢するねじりコイルスプリング５７（以下単に「コイルスプリング５７」という。）が配設されている。このコイルスプリング５７の一端はシールド６０に係合され、他端はバルブシャフト５１の露出部５１ａの先端に固設されたシャフトレバー５９に係合されている。なお、上記シールド６０は、コイルスプリング５７およびシャフトレバー５９を覆ってこれらを撥ね泥、撥ね水などから保護するものである。   Around the oblique lower end side of the shaft case 53 and the valve shaft 51, a torsion coil spring 57 (hereinafter simply referred to as “coil spring 57”) that urges the valve shaft 51 to rotate in the direction in which the valve 20 is closed is disposed. Has been. One end of the coil spring 57 is engaged with the shield 60, and the other end is engaged with a shaft lever 59 fixed to the tip of the exposed portion 51 a of the valve shaft 51. The shield 60 covers the coil spring 57 and the shaft lever 59 and protects them from splashing mud and splashing water.

上記シャフトレバー５９としては、カム状のものが使用されている。シャフトレバー５９は、アクチュエータ７０の伸縮するロッド７１の先端部によって押圧可能な位置に配設されており、上記ロッド７１の押圧力を受けると、そのロッド７１の移動量に応じてバルブシャフト５１およびバルブ２０を開側へ回転するようになっている。一方、アクチュエータ７０のロッド７１が収縮すると、コイルスプリング５７の回転付勢力によって、バルブシャフト５１およびバルブ２０は閉側へ回転するようになっている。なお、本実施形態では、アクチュエータ７０として、排気熱回収器１を循環する冷却水温度に応じてロッド７１を伸縮作動するサーモ式アクチュエータが採用されている。   As the shaft lever 59, a cam-shaped one is used. The shaft lever 59 is disposed at a position where it can be pressed by the distal end portion of the rod 71 that expands and contracts the actuator 70. When the pressing force of the rod 71 is received, the valve shaft 51 and the shaft lever 59 are moved according to the movement amount of the rod 71. The valve 20 is rotated to the open side. On the other hand, when the rod 71 of the actuator 70 contracts, the valve shaft 51 and the valve 20 are rotated to the closed side by the rotational biasing force of the coil spring 57. In the present embodiment, as the actuator 70, a thermo-type actuator that extends and retracts the rod 71 in accordance with the temperature of the cooling water circulating through the exhaust heat recovery device 1 is employed.

次に、熱交換部３０について説明する。説明の便宜のため、以下では、熱交換部３０内の排気ガスの流れ方向にかかわらず、排気熱回収器１が設置される排気系の上流側（図４中左側）を排気系上流側といい、排気熱回収器１が設置される排気系の下流側（図４中右側）を排気系下流側という。   Next, the heat exchange unit 30 will be described. For convenience of explanation, the upstream side (the left side in FIG. 4) where the exhaust heat recovery device 1 is installed will be referred to as the upstream side of the exhaust system regardless of the flow direction of the exhaust gas in the heat exchanging unit 30 below. The downstream side of the exhaust system where the exhaust heat recovery device 1 is installed (the right side in FIG. 4) is called the exhaust system downstream side.

熱交換部３０は、内筒部１０と外筒部４０との間に設けられており、冷却水流路３１ａ、３１ｂ、熱回収排気ガス流路３２ａ、３２ｂ等で構成されている。これらは、内筒部１０より外側に向かって、内側熱回収排気ガス流路（第１排気ガス流路）３２ａ、内側冷却水流路３１ａ、外側熱回収排気ガス流路（第２排気ガス流路）３２ｂ、外側冷却水流路３１ｂの順に配設されている。   The heat exchange part 30 is provided between the inner cylinder part 10 and the outer cylinder part 40, and is composed of cooling water passages 31a and 31b, heat recovery exhaust gas passages 32a and 32b, and the like. These are the inner heat recovery exhaust gas flow path (first exhaust gas flow path) 32a, the inner cooling water flow path 31a, the outer heat recovery exhaust gas flow path (second exhaust gas flow path) toward the outside from the inner cylinder portion 10. ) 32b and the outer cooling water flow path 31b are arranged in this order.

内側熱回収排気ガス流路３２ａは、内筒部１０の連通孔１２ａより流出する排気ガスを排気系上流側へ誘導するように形成されている。この内側熱回収排気ガス流路３２ａの内側壁面３２ａａは第２内筒部１２の外周面で構成され、内側熱回収排気ガス流路３２ａの外側壁面３２ａｂは内側冷却水流路３１ａとの間の隔壁で構成されている。上記外側壁面３２ａｂは、排気系下流側端部から排気系上流側に向かって（バルブ２０閉鎖時の排気ガスの流れ方向に向かって）縮径した縮径部Ｘを有している。したがって、この縮径部Ｘの下部（周方向最低部）は、後述する凝縮水排出路３３の入口に向かって下降傾斜した傾斜部Ｘａとなっている。また、内側熱回収排気ガス流路３２ａの排気系下流側端部３２ａｃの下部（周方向最低部）には、内側熱回収排気ガス流路３２ａと排気ガス排出エリアＺとを連通する凝縮水排出路（第１凝縮水排出路）３３が設けられている。   The inner heat recovery exhaust gas flow path 32a is formed to guide the exhaust gas flowing out from the communication hole 12a of the inner cylinder portion 10 to the upstream side of the exhaust system. The inner wall surface 32aa of the inner heat recovery exhaust gas flow path 32a is formed by the outer peripheral surface of the second inner cylinder portion 12, and the outer wall surface 32ab of the inner heat recovery exhaust gas flow path 32a is a partition wall between the inner heat recovery exhaust gas flow path 32a and the inner cooling water flow path 31a. It consists of The outer wall surface 32ab has a reduced diameter portion X that is reduced in diameter from the downstream end portion of the exhaust system toward the upstream side of the exhaust system (toward the flow direction of the exhaust gas when the valve 20 is closed). Accordingly, the lower portion (the lowest circumferential portion) of the reduced diameter portion X is an inclined portion Xa that is inclined downward toward the inlet of the condensed water discharge passage 33 described later. Further, a condensed water discharge that communicates the inner heat recovery exhaust gas flow path 32a and the exhaust gas discharge area Z is provided at the lower portion (the lowest circumferential direction) of the exhaust system downstream end 32ac of the inner heat recovery exhaust gas flow path 32a. A passage (first condensed water discharge passage) 33 is provided.

外側熱回収排気ガス流路３２ｂは、内側熱回収排気ガス流路３２ａの排気系上流側端部に連通しており、内側熱回収排気ガス流路３２ａから導入される排気ガスを内側熱回収排気ガス流路３２ａの外周側で排気系下流側へ誘導するように形成されている。   The outer heat recovery exhaust gas flow path 32b communicates with the exhaust system upstream end of the inner heat recovery exhaust gas flow path 32a, and exhaust gas introduced from the inner heat recovery exhaust gas flow path 32a is used as the inner heat recovery exhaust gas. It is formed so as to be guided downstream of the exhaust system on the outer peripheral side of the gas flow path 32a.

内側冷却水流路３１ａと外側冷却水流路３１ｂとは複数箇所において連通部Ｈにより冷却水（冷媒）が流通可能なように連通されている。   The inner cooling water flow path 31a and the outer cooling water flow path 31b are communicated with each other so that cooling water (refrigerant) can be circulated by the communication portion H at a plurality of locations.

つぎに、外筒部４０その他の構成について説明する。外筒部４０は、外側冷却水流路３１ｂの外周壁を構成するとともに、バルブ２０の配置箇所より更に下流側へ延出している。外筒部４０の排気系下流側端部には、この排気熱回収器１の下流側の排気系構成部材と接続され、外筒部４０内を通過した排気ガスを排出する排出口４０ａが形成されている。なお、外筒部４０の上流側端部と第１内筒部１１の外周面との間は閉塞部材４１によって、第２内筒部１２の外周面と内側冷却水流路形成部材３５の下流側端部との間は閉塞部材３６によってそれぞれ閉塞されている。   Next, the outer cylinder portion 40 and other configurations will be described. The outer cylinder part 40 constitutes the outer peripheral wall of the outer cooling water flow path 31b and extends further downstream than the place where the valve 20 is disposed. An exhaust port 40 a that is connected to an exhaust system constituent member on the downstream side of the exhaust heat recovery device 1 and exhausts exhaust gas that has passed through the outer cylinder portion 40 is formed at the exhaust system downstream end of the outer cylinder portion 40. Has been. In addition, between the upstream end of the outer cylinder part 40 and the outer peripheral surface of the first inner cylinder part 11 is a blocking member 41, and the outer peripheral surface of the second inner cylinder part 12 and the downstream side of the inner cooling water flow path forming member 35. The gap between the ends is closed by a closing member 36.

図１および図２に示すように、外筒部４０の側底部には、内側冷却水流路３１ａおよび外側冷却水流路３１ｂに連通し、これら冷却水流路３１ａ，３１ｂに冷却水を導入する冷却水導入用配管８０が接続されている。また、外筒部４０の上部には、外側冷却水流路３１ｂに連通し、加熱された冷却水を排出するための冷却水排出用配管８１が接続されている。   As shown in FIGS. 1 and 2, the side bottom of the outer cylinder portion 40 communicates with the inner cooling water flow path 31a and the outer cooling water flow path 31b, and the cooling water introduces cooling water into these cooling water flow paths 31a and 31b. An introduction pipe 80 is connected. Further, a cooling water discharge pipe 81 for discharging heated cooling water is connected to the upper portion of the outer cylinder portion 40 so as to communicate with the outer cooling water flow path 31b.

つぎに、排気熱回収器１による排気ガスの熱回収について説明する。   Next, heat recovery of exhaust gas by the exhaust heat recovery device 1 will be described.

エンジン（内燃機関）から排出された排気ガスが内筒部１０内を流れる際に、バルブ２０が閉じられていると、内筒部１０内に流れ込んだ排気ガスは、図４の矢印に示すように、連通孔１２ａを通過して、内側熱回収排気ガス流路３２ａへ導入され排気系上流側（図４中左側）へ向かって流れる。そして、その排気ガスは、内側冷却水流路３１ａ内の冷却水との間で熱交換を行った後、閉塞部材４１内で反転して外側熱回収排気ガス流路３２ｂへ導入される。外側熱回収排気ガス流路３２ｂ内を流れる排気ガスは、内側冷却水流路３１ａおよび外側冷却水流路３１ｂ内の冷却水との間で熱交換を行いつつ、外側熱回収排気ガス流路３２ｂを通り抜け、熱交換部３０の排気ガス排出口Ｅより排気ガス排出エリアＺを経て、外筒部４０の排出口４０ａに接続された下流側の排気系構成部材へと排出される。   When the exhaust gas discharged from the engine (internal combustion engine) flows through the inner cylinder portion 10 and the valve 20 is closed, the exhaust gas flowing into the inner cylinder portion 10 is as shown by an arrow in FIG. Then, the air passes through the communication hole 12a, is introduced into the inner heat recovery exhaust gas passage 32a, and flows toward the exhaust system upstream side (left side in FIG. 4). The exhaust gas exchanges heat with the cooling water in the inner cooling water passage 31a, and then reverses in the closing member 41 and is introduced into the outer heat recovery exhaust gas passage 32b. The exhaust gas flowing in the outer heat recovery exhaust gas passage 32b passes through the outer heat recovery exhaust gas passage 32b while exchanging heat between the inner cooling water passage 31a and the cooling water in the outer cooling water passage 31b. Then, the exhaust gas is discharged from the exhaust gas discharge port E of the heat exchanging part 30 through the exhaust gas discharge area Z to the exhaust system constituent member on the downstream side connected to the discharge port 40a of the outer cylinder part 40.

このとき、冷却水導入用配管８０から冷却水流路３１ａ、３１ｂ内に導入された冷却水は、熱回収排気ガス流路３２ａ、３２ｂを流れる排気ガスとの熱交換によって加熱され、冷却水排出用配管８１から排気熱回収器１の外へ導出される。   At this time, the cooling water introduced into the cooling water flow paths 31a and 31b from the cooling water introduction pipe 80 is heated by heat exchange with the exhaust gas flowing through the heat recovery exhaust gas flow paths 32a and 32b, and is used for cooling water discharge. It is led out of the exhaust heat recovery unit 1 from the pipe 81.

一方、排気熱回収器１で排気ガスの熱を回収しない場合や排気熱回収器１で回収する熱量を抑える場合はバルブ２０が開放される。バルブ２０が開放されると、内筒部１０の連通孔１２ａを通じて、内側熱回収排気ガス流路３２ａへ導入されていた排気ガスの大部分が、内筒部１０の下流側の開口部１２ｂを通過し、排気ガス排出エリアＺを経て、外筒部４０の排出口４０ａから下流側の排気系構成要素へ排出される。その結果、熱回収排気ガス流路３２ａ、３２ｂに導入される排気ガスは、大幅に減少し、回収される排気ガスの熱量が低減される。   On the other hand, when the exhaust heat recovery device 1 does not recover the heat of the exhaust gas, or when the amount of heat recovered by the exhaust heat recovery device 1 is suppressed, the valve 20 is opened. When the valve 20 is opened, most of the exhaust gas introduced into the inner heat recovery exhaust gas passage 32a through the communication hole 12a of the inner cylinder part 10 passes through the opening 12b on the downstream side of the inner cylinder part 10. It passes through the exhaust gas discharge area Z and is discharged from the discharge port 40a of the outer cylinder portion 40 to the exhaust system components on the downstream side. As a result, the exhaust gas introduced into the heat recovery exhaust gas passages 32a and 32b is greatly reduced, and the amount of heat of the recovered exhaust gas is reduced.

つぎに、排気熱回収器１に発生する凝縮水の排水について説明する。   Next, drainage of condensed water generated in the exhaust heat recovery unit 1 will be described.

図６に示すように、バルブ２０を閉鎖した状態（排気熱回収状態）で、内筒部１０内に上流側から排気ガスが流れ込むと、エンジンの運転開始初期時など内筒部１０の温度が昇温する前において、内筒部１０の内周面に凝縮水が発生する場合がある。この場合、内筒部１０の内周面に発生した凝縮水は、内筒部１０の内周面に沿って、周方向低位置側へ流下しつつ、排気ガスによって下流側に流される。その結果、内筒部１０の内周面に発生した凝縮水は、内筒部１０の下流側端部の最下部に集まり、集まった凝縮水Ｗ１は、凝縮水排出路１４から排気ガス排出エリアＺへと排出される。   As shown in FIG. 6, when the exhaust gas flows into the inner cylinder portion 10 from the upstream side in a state where the valve 20 is closed (exhaust heat recovery state), the temperature of the inner cylinder portion 10 is increased such as at the initial start of engine operation. Before the temperature rises, condensed water may be generated on the inner peripheral surface of the inner cylinder portion 10. In this case, the condensed water generated on the inner peripheral surface of the inner cylinder portion 10 flows downstream along the inner peripheral surface of the inner cylinder portion 10 toward the lower position in the circumferential direction by the exhaust gas. As a result, the condensed water generated on the inner peripheral surface of the inner cylinder portion 10 gathers at the lowermost portion of the downstream end portion of the inner cylinder portion 10, and the collected condensed water W1 is discharged from the condensed water discharge path 14 to the exhaust gas discharge area. Discharged to Z.

また、内側熱回収排気ガス流路３２ａの外側壁面３２ａｂにも凝縮水が発生し易い。ここに凝縮水が発生すると、その凝縮水は、外側壁面３２ａｂに沿って、周方向低位置側へ流下し、外側壁面３２ａｂの傾斜部Ｘａでは、より低位置側となる排気系下流側（図６中右側）にある凝縮水排出路３３の入口に向かって流れる。そして、凝縮水排出路３３の入口に集まった凝縮水Ｗ３は、凝縮水排出路３３から排気ガス排出エリアＺへ排出される。   Further, condensed water is likely to be generated also on the outer wall surface 32ab of the inner heat recovery exhaust gas passage 32a. When condensed water is generated here, the condensed water flows along the outer wall surface 32ab to the lower side in the circumferential direction, and at the inclined portion Xa of the outer wall surface 32ab, the exhaust system downstream side (see FIG. It flows toward the inlet of the condensed water discharge passage 33 located on the right side in FIG. The condensed water W3 collected at the inlet of the condensed water discharge path 33 is discharged from the condensed water discharge path 33 to the exhaust gas discharge area Z.

一方、外側壁面３２ａｂの傾斜部Ｘａ以外の場所に流下した凝縮水Ｗ４は、内側熱回収排気ガス流路３２ａ内を流れる排気ガスによって、外側熱回収排気ガス流路３２ｂ側へ送出され、外側熱回収排気ガス流路３２ｂ内で発生する凝縮水とともに、熱交換部３０の排気ガス排出口Ｅからら排気ガス排出エリアＺへと排出される。   On the other hand, the condensed water W4 that has flowed down to a place other than the inclined portion Xa of the outer wall surface 32ab is sent to the outer heat recovery exhaust gas flow path 32b side by the exhaust gas flowing in the inner heat recovery exhaust gas flow path 32a. Along with the condensed water generated in the recovered exhaust gas flow path 32b, the exhaust gas is discharged from the exhaust gas discharge port E of the heat exchange unit 30 to the exhaust gas discharge area Z.

なお、排気ガス排出エリアＺへ排出された凝縮水は、熱交換部３０を通り抜けた排気ガス流によって器外下流側（外筒部４０の排出口４０ａに接続された下流側の排気系構成部材）へ排出される。また、バルブ２０が開放されると、排気ガス排出エリアＺへ排出された凝縮水は、内筒部１０の開口部１２ｂから噴出する高速の排気ガスによっても器外下流側へ排出される。   In addition, the condensed water discharged to the exhaust gas discharge area Z is exhausted downstream by the exhaust gas flow that has passed through the heat exchanging unit 30 (downstream exhaust system components connected to the discharge port 40a of the outer tube 40). ). When the valve 20 is opened, the condensed water discharged to the exhaust gas discharge area Z is also discharged to the downstream side by the high-speed exhaust gas ejected from the opening portion 12b of the inner cylinder portion 10.

以下、上記排気熱回収器１によるその他の作用効果について説明する。   Hereinafter, other functions and effects of the exhaust heat recovery device 1 will be described.

排気熱回収器１の内側熱回収排気ガス流路３２ａでは、外側壁面３２ａｂの縮径部Ｘにおいて、流れ方向に向かって排気ガスの通過断面積が漸次減少するため、排気ガスの流速が増加する。排気ガスの流速が増加すると、外側壁面３２ａｂに対する伝熱量が増加するので、内側冷却水流路３１ａを流れる冷却水との熱交換量も増加し、熱回収効率が高くなる。   In the inner heat recovery exhaust gas flow path 32a of the exhaust heat recovery device 1, the exhaust gas passage cross-sectional area gradually decreases in the reduced diameter portion X of the outer wall surface 32ab in the flow direction, so that the exhaust gas flow velocity increases. . When the flow rate of the exhaust gas increases, the amount of heat transfer to the outer wall surface 32ab increases, so the amount of heat exchange with the cooling water flowing through the inner cooling water channel 31a also increases, and the heat recovery efficiency increases.

ここで、上記伝熱量の増加理由を説明する。ニュートンの冷却法則によれば、内側熱回収排気ガス流路３２ａの外側壁面３２ａｂの微小面積ｄＳ［ｍ2］を通して、ｄτ［ｓ］の間に内側熱回収排気ガス流路３２ａを流れる排気ガスから外側壁面３２ａｂに伝わる伝熱量ｄＱは、
ｄＱ ＝ ｈ（Ｔ0−Ｔw）ｄＳ・ｄτ ［Ｊ（ジュール）］・・・・・・（式１）
で表すことができる。ここで、ｈは熱伝達率［Ｗ／（ｍ2・Ｋ）］であり、
ｈ ＝ Ｎｕ×（熱伝導率）／（管径）・・・・・・・・・・・・・・・（式２）
で表すことができる。ここで、熱伝導率［Ｗ／（ｍ・Ｋ）］は、外側壁面３２ａｂの熱伝導率であり、管径［ｍ］は、内側熱回収排気ガス流路３２ａの外径である。また、Ｔw、Ｔ0［Ｋ］は、それぞれ、外側壁面３２ａｂの表面温度および排気ガスの代表温度である。 Here, the reason for the increase in the heat transfer amount will be described. According to Newton's cooling law, from the exhaust gas flowing through the inner heat recovery exhaust gas passage 32a during dτ [s] through the minute area dS [m 2 ] of the outer wall surface 32ab of the inner heat recovery exhaust gas passage 32a. The heat transfer amount dQ transmitted to the outer wall surface 32ab is
dQ = h (T 0 −T w ) dS · dτ [J (joule)] (Equation 1)
Can be expressed as Here, h is a heat transfer coefficient [W / (m 2 · K)],
h = Nu × (thermal conductivity) / (tube diameter) (Equation 2)
Can be expressed as Here, the thermal conductivity [W / (m · K)] is the thermal conductivity of the outer wall surface 32ab, and the tube diameter [m] is the outer diameter of the inner heat recovery exhaust gas passage 32a. T w and T 0 [K] are the surface temperature of the outer wall surface 32ab and the representative temperature of the exhaust gas, respectively.

また、マックアダムスの法則によれば、ヌセルト数Ｎｕは、
Ｎｕ ＝ ０．０５３×Ｒｅ0.8Ｐｒ0.4・・・・・・・・・・・・・・・（式３）
で表すことができる。ここで、Ｒｅはレイノルズ数、Ｐｒはプラントル数である。 Also, according to McAdams law, the Nusselt number Nu is
Nu = 0.053 × Re 0.8 Pr 0.4 (Equation 3)
Can be expressed as Here, Re is the Reynolds number and Pr is the Prandtl number.

また、レイノルズ数Ｒｅは、
Ｒｅ＝ｕ×Ｄ／ν・・・・・・・・・・・・・・・・・・・・・・・・・・（式４）
で表すことができる。ここで、ｕは、排気ガスの流速［ｍ／ｓ］、Ｄは、管径（内側熱回収排気ガス流路３２ａの外径）［ｍ］、νは排気ガスの動粘度［ｍ2／ｓ］である。 The Reynolds number Re is
Re = u × D / ν (Equation 4)
Can be expressed as Here, u is an exhaust gas flow velocity [m / s], D is a pipe diameter (outer diameter of the inner heat recovery exhaust gas flow path 32a) [m], and ν is an exhaust gas kinematic viscosity [m 2 / s. ].

式４より、レイノルズ数Ｒｅは、排気ガスの流速ｕに比例するといえる。また、プラントル数Ｐｒはほぼ一定であるとみなすことができるので、式３のヌセルト数Ｎｕは、レイノルズ数Ｒｅの増加に伴って増加する。また、式３を式２に代入すると、熱伝達率ｈは、ヌセルト数Ｎｕに比例することがわかる。さらに、式２を式１に代入すると、伝熱量ｄＱは、伝熱率ｈとともに増減することがわかる。このことは、伝熱量ｄＱが、排気ガスの流速ｕの増加に伴って増加することを示している。したがって、内側熱回収排気ガス流路３２ａを流れる排気ガスの流速が増加すると、排気ガスの内側冷却水流路３１ａを流れる冷却水に対する伝熱量が増加し、熱回収効率が高くなるといえる。   From Equation 4, it can be said that the Reynolds number Re is proportional to the flow rate u of the exhaust gas. Further, since the Prandtl number Pr can be regarded as being substantially constant, the Nusselt number Nu in the equation 3 increases as the Reynolds number Re increases. Moreover, when Formula 3 is substituted into Formula 2, it can be seen that the heat transfer coefficient h is proportional to the Nusselt number Nu. Furthermore, when Formula 2 is substituted into Formula 1, it can be seen that the heat transfer amount dQ increases and decreases with the heat transfer rate h. This indicates that the heat transfer amount dQ increases as the flow rate u of the exhaust gas increases. Therefore, it can be said that when the flow rate of the exhaust gas flowing through the inner heat recovery exhaust gas passage 32a increases, the amount of heat transfer to the cooling water flowing through the inner cooling water passage 31a of the exhaust gas increases, and the heat recovery efficiency increases.

以下、上記排気熱回収器１による更にその他の作用効果について説明する。   Hereinafter, other functions and effects of the exhaust heat recovery device 1 will be described.

従来より、排気熱回収器では、暖機運転の完了後、バルブを開放することで排気熱の回収を抑制するようにしているが、バルブ開放状態においても熱交換部を少量の排気ガスが通過してしまうことにより、冷却水の温度を上昇させてしまうことがあった。   Conventionally, exhaust heat recovery devices have been designed to suppress exhaust heat recovery by opening the valve after the warm-up operation is complete, but a small amount of exhaust gas passes through the heat exchanger even when the valve is open. As a result, the temperature of the cooling water may be increased.

例えば、排気熱回収器１において、凝縮水排出路３３が設けられていなければ、エンジンの負荷が高いとき（排気系を流れる排気ガスの量が多いとき）に、バルブ３０を開放すると、図７の矢印Ｐに示すように、内筒部１０内を比較的高速度で流れる排気ガスによって、内側熱回収排気ガス流路３２ａ内の排気ガスが、連通孔１２ａを通じて内筒部１０内に吸込まれる。この動きに連動して、排気ガス排出エリアＺにある排気ガスが熱交換部３０の排気ガス排出口Ｅから吸込まれ、熱回収排気ガス流路３２ａ、３２ｂ内を排気ガスが逆流するようになる。その結果、逆流する排気ガスと冷却水との間で熱交換が行われ、冷却水の温度を必要もなく上昇させてしまう。   For example, in the exhaust heat recovery device 1, if the condensed water discharge passage 33 is not provided, when the valve 30 is opened when the engine load is high (the amount of exhaust gas flowing through the exhaust system is large), FIG. As indicated by the arrow P, the exhaust gas in the inner heat recovery exhaust gas passage 32a is sucked into the inner cylinder part 10 through the communication hole 12a by the exhaust gas flowing at a relatively high speed in the inner cylinder part 10. It is. In conjunction with this movement, the exhaust gas in the exhaust gas discharge area Z is sucked from the exhaust gas discharge port E of the heat exchanging section 30, and the exhaust gas flows backward in the heat recovery exhaust gas flow paths 32a and 32b. . As a result, heat exchange is performed between the exhaust gas flowing backward and the cooling water, and the temperature of the cooling water is increased without necessity.

しかし、本発明の実施の形態に係る排気熱回収器１によれば、内側熱回収排気ガス流路３２ａと排気ガス排出エリアＺとを直接的に連通する連通路となる凝縮水排出路３３が設けられていることから、上記熱回収排気ガス流路３２ａ、３２ｂ内での排気ガスの逆流が抑制される。   However, according to the exhaust heat recovery device 1 according to the embodiment of the present invention, the condensed water discharge path 33 serving as a communication path that directly communicates the inner heat recovery exhaust gas flow path 32a and the exhaust gas discharge area Z is provided. Since it is provided, the backflow of the exhaust gas in the heat recovery exhaust gas passages 32a and 32b is suppressed.

すなわち、図８の矢印Ｑ１に示すように、内側熱回収排気ガス流路３２ａ内の排気ガスは、連通孔１２ａを通じて内筒部１０内に吸込まれるものの、排気ガス排出エリアＺにある排気ガスは、矢印Ｑ２に示すように、熱交換部の排気ガス排出口Ｅよりも吸入抵抗の小さい凝縮水排出路３３から吸入され易くなる。この結果、熱回収排気ガス流路３２ａ、３２ｂ内を逆流する排気ガスの流量が大幅に低減され、冷却水の不必要な温度上昇を抑えることができる。   That is, as shown by the arrow Q1 in FIG. 8, the exhaust gas in the inner heat recovery exhaust gas passage 32a is sucked into the inner cylinder portion 10 through the communication hole 12a, but is in the exhaust gas discharge area Z. Is easily sucked from the condensed water discharge passage 33 having a suction resistance smaller than that of the exhaust gas discharge port E of the heat exchange section, as indicated by an arrow Q2. As a result, the flow rate of the exhaust gas flowing backward in the heat recovery exhaust gas passages 32a and 32b is greatly reduced, and an unnecessary temperature rise in the cooling water can be suppressed.

＜他の実施形態＞
既述した実施形態では、図３および図４に示したように、凝縮水排出路３３は、内側熱回収排気ガス流路３２ａの排気系下流側端部３２ａｃの下部（周方向最下位置）において周方向小範囲にて形成されているが、熱回収排気ガス流路３２ａ、３２ｂ内での上記排気ガスの逆流をより積極的に抑制する場合は、凝縮水排出路３３を更に周方向に拡張したものとしたり、内側熱回収排気ガス流路３２ａの排気系下流側端部３２ａｃの下部以外の場所、例えば内側熱回収排気ガス流路３２ａの排気系下流側端部３２ａｃの上部などに、内側熱回収排気ガス流路３２ａと排気ガス排出エリアＺとを直接的に連通する連通路を形成してもよい。 <Other embodiments>
In the embodiment described above, as shown in FIGS. 3 and 4, the condensed water discharge passage 33 is the lower part (circumferential bottom position) of the exhaust system downstream end 32ac of the inner heat recovery exhaust gas passage 32a. However, when the backflow of the exhaust gas in the heat recovery exhaust gas passages 32a and 32b is more positively suppressed, the condensed water discharge passage 33 is further extended in the circumferential direction. It can be expanded, or in places other than the lower part of the exhaust system downstream end 32ac of the inner heat recovery exhaust gas flow path 32a, for example, the upper part of the exhaust system downstream end 32ac of the inner heat recovery exhaust gas flow path 32a, etc. A communication path that directly communicates the inner heat recovery exhaust gas passage 32a and the exhaust gas discharge area Z may be formed.

本実施形態では、縮径部Ｘは周方向全体に亘って形成されているが、内側熱回収排気ガス流路３２ａ内に発生した凝縮水の排水のみを目的とする場合は、縮径部Ｘは、必ずしも周方向全体に亘って形成されている必要はない。例えば、周方向最低位置近傍のみに縮径部Ｘが設けられていてもよい。   In the present embodiment, the reduced diameter portion X is formed over the entire circumferential direction. However, when only the drainage of the condensed water generated in the inner heat recovery exhaust gas passage 32a is intended, the reduced diameter portion X is formed. Need not be formed over the entire circumferential direction. For example, the reduced diameter portion X may be provided only in the vicinity of the lowest circumferential position.

また、本実施形態では、縮径部Ｘは内側熱回収排気ガス流路３２ａの途中から排気系下流側端部に亘って設けられているが、内側熱回収排気ガス流路３２ａの排気系上流側端部から排気系下流側端部に亘って設けられていてもよい。   In the present embodiment, the reduced diameter portion X is provided from the middle of the inner heat recovery exhaust gas passage 32a to the downstream end of the exhaust system, but the exhaust system upstream of the inner heat recovery exhaust gas passage 32a. It may be provided from the side end to the exhaust system downstream end.

本発明は、エンジンの排気ガスの熱を回収するための排気熱回収器に適用することが可能である。   The present invention can be applied to an exhaust heat recovery device for recovering heat of exhaust gas of an engine.

本発明の実施の形態に係る排気熱回収器の側面図である。It is a side view of the exhaust heat recovery device concerning an embodiment of the invention. 本発明の実施の形態に係る排気熱回収器の平面図である。It is a top view of the exhaust heat recovery device concerning an embodiment of the invention. 図１のＡ−Ａ断面図である。It is AA sectional drawing of FIG. 本発明の実施の形態に係る排気熱回収器の縦断面図である。It is a longitudinal section of an exhaust heat recovery device concerning an embodiment of the invention. 図４のＢ矢視図であって、一部を省略して表した図である。FIG. 5 is a view taken in the direction of arrow B in FIG. 4, with a part omitted. 本発明の実施の形態に係る排気熱回収器の縦断面図であって、凝縮水の排水作用を説明する説明図である。It is a longitudinal cross-sectional view of the exhaust heat recovery device which concerns on embodiment of this invention, Comprising: It is explanatory drawing explaining the drainage effect | action of condensed water. 第１凝縮水排出路が設けられていない排気熱回収器において、バルブ開放時に器内を流れる排気ガスの流れを示した図である。In the exhaust heat recovery device in which the 1st condensed water discharge way is not provided, it is a figure showing the flow of the exhaust gas which flows through the inside at the time of valve opening. 第１凝縮水排出路が設けられた本発明の実施の形態に係る排気熱回収器において、バルブ開放時に器内を流れる排気ガスの流れを示した図である。In the exhaust heat recovery device according to the embodiment of the present invention provided with a first condensate discharge path, it is a diagram showing the flow of exhaust gas flowing in the device when the valve is opened. 第１および第２凝縮水排出路が設けられていない排気熱回収器の縦断面図である。It is a longitudinal cross-sectional view of the exhaust heat recovery device in which the 1st and 2nd condensed water discharge path is not provided.

符号の説明Explanation of symbols

Ｅ 熱交換部の排気ガス排出口
Ｈ 連通路
Ｘａ 傾斜部
Ｚ 排気ガス排出エリア
１０ 内筒部
１２ｂ 開口部（排気ガス排出口）
１４ 凝縮水排出路（第２凝縮水排出路）
２０ バルブ
３０ 熱交換部
３１ａ 内側冷却水流路（冷媒流路）
３１ｂ 外側冷却水流路（冷媒流路）
３２ａ 内側熱回収排気ガス流路（第１排気ガス流路）
３２ｂ 外側熱回収排気ガス流路（第２排気ガス流路）
３３ 凝縮水排出路（第１凝縮水排出路）
４０ 外筒部 E Exhaust gas discharge port of heat exchange unit H Communication passage Xa Inclined part Z Exhaust gas discharge area 10 Inner cylinder 12b Opening (exhaust gas discharge port)
14 Condensate drain (second condensed drain)
20 Valve 30 Heat exchange part 31a Inner cooling water flow path (refrigerant flow path)
31b Outer cooling water channel (refrigerant channel)
32a Inner heat recovery exhaust gas passage (first exhaust gas passage)
32b Outside heat recovery exhaust gas flow path (second exhaust gas flow path)
33 Condensate drain (first condensate drain)
40 outer tube

Claims (3)

側部に連通路を有する内筒部と、
前記連通路より排気系下流側で前記内筒部内の排気ガス流路を開閉するバルブと、
前記内筒部の外周側に間隔をおいて設けられた外筒部と、
前記内筒部と前記外筒部との間に設けられた熱交換部と、
を備え、
前記熱交換部は、前記内筒部の連通路より流出する排気ガスを排気系上流側へ誘導する第１排気ガス流路と、
前記第１排気ガス流路の排気系上流側端部に連通され、前記第１排気ガス流路から導入される排気ガスを前記第１排気ガス流路の外周側で排気系下流側へ誘導する第２排気ガス流路と、
前記第１排気ガス流路および前記第２排気ガス流路を通過する排気ガスと熱交換可能に冷媒を循環させる冷媒流路と、
を備える排気熱回収器であって、
前記第１排気ガス流路と、前記内筒部および前記熱交換部の排気ガス排出口より排出される排気ガスの排出エリアとを連通する第１凝縮水排出路が設けられた、
ことを特徴とする排気熱回収器。 An inner cylinder having a communication path on the side,
A valve for opening and closing an exhaust gas flow path in the inner cylinder portion on the exhaust system downstream side from the communication path;
An outer cylindrical portion provided at an interval on the outer peripheral side of the inner cylindrical portion;
A heat exchange part provided between the inner cylinder part and the outer cylinder part,
With
The heat exchanging section includes a first exhaust gas flow path for guiding exhaust gas flowing out from the communication path of the inner cylinder section to the exhaust system upstream side;
The exhaust gas is communicated with an upstream end portion of the first exhaust gas flow path, and introduces exhaust gas introduced from the first exhaust gas flow path to the downstream side of the exhaust system on the outer peripheral side of the first exhaust gas flow path. A second exhaust gas flow path;
A refrigerant flow path for circulating a refrigerant so as to exchange heat with the exhaust gas passing through the first exhaust gas flow path and the second exhaust gas flow path;
An exhaust heat recovery device comprising:
A first condensate discharge path is provided that communicates the first exhaust gas flow path with an exhaust gas discharge area discharged from an exhaust gas discharge port of the inner cylinder part and the heat exchange part;
An exhaust heat recovery device characterized by that. 請求項１に記載の排気熱回収器において、
前記第１排気ガス流路の外側壁面の下部に前記第１凝縮水排出路の入口に向かって下降傾斜した傾斜部が形成されていることを特徴とする排気熱回収器。 The exhaust heat recovery device according to claim 1,
An exhaust heat recovery device, wherein an inclined portion that is inclined downward toward the inlet of the first condensed water discharge passage is formed at a lower portion of an outer wall surface of the first exhaust gas passage. 請求項１又は２に記載の排気熱回収器において、
前記内筒部の排気系下流側端部の下部に、前記排気ガスの排出エリアへ連通する第２凝縮水排出路が設けられたことを特徴とする排気熱回収器。 The exhaust heat recovery device according to claim 1 or 2,
An exhaust heat recovery device, wherein a second condensate discharge path communicating with the exhaust gas discharge area is provided at a lower portion of an exhaust system downstream end portion of the inner cylinder portion.
JP2008191972A 2008-07-25 2008-07-25 Exhaust heat recovery unit Expired - Fee Related JP4821816B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2008191972A JP4821816B2 (en) 2008-07-25 2008-07-25 Exhaust heat recovery unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2008191972A JP4821816B2 (en) 2008-07-25 2008-07-25 Exhaust heat recovery unit

Publications (2)

Publication Number Publication Date
JP2010031671A JP2010031671A (en) 2010-02-12
JP4821816B2 true JP4821816B2 (en) 2011-11-24

Family

ID=41736444

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2008191972A Expired - Fee Related JP4821816B2 (en) 2008-07-25 2008-07-25 Exhaust heat recovery unit

Country Status (1)

Country Link
JP (1) JP4821816B2 (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101123161B1 (en) 2010-05-03 2012-03-20 세종공업 주식회사 Exhaust heat recovery apparatus
KR101241211B1 (en) * 2010-12-09 2013-03-13 현대자동차주식회사 Heat exchanger for exhaust heat withdrawal of vehicle
DE102011016808A1 (en) 2011-04-13 2012-10-18 Emitec Gesellschaft Für Emissionstechnologie Mbh Device with a heat exchanger for a thermoelectric generator of a motor vehicle
DE102011016886A1 (en) 2011-04-13 2012-10-18 Emitec Gesellschaft Für Emissionstechnologie Mbh Device with a heat exchanger for a thermoelectric generator of a motor vehicle
JP5848906B2 (en) * 2011-07-14 2016-01-27 富士重工業株式会社 Vehicle heat exchange device
JP5691999B2 (en) * 2011-10-26 2015-04-01 トヨタ自動車株式会社 Thermoelectric generator
JP5911169B2 (en) * 2012-01-25 2016-04-27 本田技研工業株式会社 Heat exchanger
JP2014034922A (en) 2012-08-08 2014-02-24 Suzuki Motor Corp Exhaust heat recovery device
DE102012107908B4 (en) 2012-08-28 2018-11-15 Tenneco Gmbh Exhaust gas heat exchanger
JP6425478B2 (en) * 2014-09-17 2018-11-21 フタバ産業株式会社 Exhaust heat recovery system
JP6725204B2 (en) * 2014-12-03 2020-07-15 フタバ産業株式会社 Exhaust heat recovery device

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006258084A (en) * 2005-03-14 2006-09-28 Sango Co Ltd Heat recovery equipment
JP2006275038A (en) * 2005-03-28 2006-10-12 Sango Co Ltd Heat recovery machine
JP2007247555A (en) * 2006-03-16 2007-09-27 Toyota Motor Corp Exhaust heat recovery device
JP2007247554A (en) * 2006-03-16 2007-09-27 Toyota Motor Corp Exhaust heat recovery device
JP2007315370A (en) * 2006-04-24 2007-12-06 Futaba Industrial Co Ltd Exhaust heat recovery exhaust emission control device
JP2007321741A (en) * 2006-06-05 2007-12-13 Toyota Motor Corp Exhaust heat recovery device

Also Published As

Publication number Publication date
JP2010031671A (en) 2010-02-12

Similar Documents

Publication Publication Date Title
JP4821816B2 (en) Exhaust heat recovery unit
US8904771B2 (en) Exhaust heat recovery apparatus for vehicle
JP5941878B2 (en) Heat exchanger and heat exchange device
JP4651394B2 (en) Four-way valve
JP4551272B2 (en) Exhaust heat recovery device
JP2008038723A (en) Supporting structure for exhaust system heat exchanger
KR101284337B1 (en) Heat exchanger for vehicle
JP2008157211A (en) Exhaust heat recovery device
JP5001752B2 (en) EGR cooler bypass switching system
WO2006090725A1 (en) Exhaust heat recovery device
JP2014034922A (en) Exhaust heat recovery device
JP4991764B2 (en) Exhaust gas cooling device
JP2015175593A (en) refrigerator
JP2007247638A (en) Exhaust heat recovery device
JP2008101481A (en) Exhaust system structure
KR101637257B1 (en) Heat exchanger for exhaust heat withdrawal of vehicle
JP2007285264A (en) Heat exchanger
JP6499326B2 (en) Exhaust heat recovery device
JP2009236447A (en) Refrigeration apparatus
JP2008101496A (en) Exhaust system heat exchanger
KR101619532B1 (en) An engine exhaust steam withdrawal apparatus of vehicle
JP2009013838A (en) Exhaust heat recovery device
KR101575267B1 (en) Heat exchanger for exhaust heat withdrawal of vehicle
JP4487926B2 (en) Cooling module
JP6296939B2 (en) Exhaust heat recovery device

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20100923

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20110726

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20110809

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20110822

R151 Written notification of patent or utility model registration

Ref document number: 4821816

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140916

Year of fee payment: 3

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313114

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees