JP2000046421A - Heat exchanger for carbon dioxide refrigeration cycle - Google Patents
Heat exchanger for carbon dioxide refrigeration cycleInfo
- Publication number
- JP2000046421A JP2000046421A JP21098398A JP21098398A JP2000046421A JP 2000046421 A JP2000046421 A JP 2000046421A JP 21098398 A JP21098398 A JP 21098398A JP 21098398 A JP21098398 A JP 21098398A JP 2000046421 A JP2000046421 A JP 2000046421A
- Authority
- JP
- Japan
- Prior art keywords
- carbon dioxide
- heat exchanger
- refrigeration cycle
- heat transfer
- film
- 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.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
- F28F13/18—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
- F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
- F28D1/04—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits
- F28D1/053—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight
- F28D1/0535—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight the conduits having a non-circular cross-section
- F28D1/05366—Assemblies of conduits connected to common headers, e.g. core type radiators
- F28D1/05383—Assemblies of conduits connected to common headers, e.g. core type radiators with multiple rows of conduits or with multi-channel conduits
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F1/00—Tubular elements; Assemblies of tubular elements
- F28F1/02—Tubular elements of cross-section which is non-circular
- F28F1/022—Tubular elements of cross-section which is non-circular with multiple channels
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2309/00—Gas cycle refrigeration machines
- F25B2309/06—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide
- F25B2309/061—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide with cycle highest pressure above the supercritical pressure
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、自動車用、家庭
用、或はビルディング用の冷房装置を構成する二酸化炭
素冷凍サイクルに組み込む熱交換器の改良に関する。こ
の様な本発明の対象となる二酸化炭素冷凍サイクル用熱
交換器には、コンプレッサから吐出された高温・高圧の
二酸化炭素と空気との間で熱交換を行なってこの二酸化
炭素を冷却する放熱器と、膨張弁を通過する事により断
熱膨張した二酸化炭素と空気との間で熱交換を行なって
この空気を冷却する冷却器と、この冷却器を出た未だ低
温の二酸化炭素と上記放熱器を出た未だ高温の二酸化炭
素とを熱交換させる内部熱交換器とが存在する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a heat exchanger incorporated in a carbon dioxide refrigeration cycle constituting a cooling system for automobiles, homes, or buildings. Such a heat exchanger for a carbon dioxide refrigeration cycle, which is an object of the present invention, includes a radiator that cools the carbon dioxide by performing heat exchange between high-temperature and high-pressure carbon dioxide discharged from a compressor and air. And a cooler that exchanges heat between the carbon dioxide and the air that are adiabatically expanded by passing through the expansion valve to cool the air, and a still-low-temperature carbon dioxide that has exited the cooler and the radiator. There is an internal heat exchanger that exchanges heat with the still hot carbon dioxide that has exited.
【０００２】[0002]
【従来の技術】冷房装置として従来一般的には、フロン
を冷媒とする蒸気圧縮式の冷凍サイクルが使用されてい
た。ところが、フロンのうち、特定フロンと呼ばれるも
のは、空気中に排出された場合にオゾン層を破壊すると
して、使用が制限されている。又、オゾン層を破壊しな
いとして、現在使用されている所謂代替フロンに関して
も、空気中に排出された場合に強力な温室効果ガスとし
て、地球の温暖化を促進する為、使用を控える事が提案
されている。2. Description of the Related Art A vapor compression refrigeration cycle using chlorofluorocarbon as a refrigerant has been conventionally used as a cooling device. However, the use of fluorocarbons, which are called specific fluorocarbons, are restricted because they destroy the ozone layer when discharged into the air. It is also suggested that the use of so-called alternative chlorofluorocarbons, which do not destroy the ozone layer, as a powerful greenhouse gas when discharged into the air, is promoted to promote global warming, so that it is not used. Have been.
【０００３】この様な事情に鑑みて近年、冷媒として二
酸化炭素（ＣＯ2 ）を使用する、二酸化炭素冷凍サイク
ルにより冷房装置を構成する事が研究されている。二酸
化炭素冷凍サイクルの基本構成はフロンを冷媒とする蒸
気圧縮式の冷凍サイクルとほぼ同様である。但し、二酸
化炭素は、フロンに比べて液化する領域（温度及び圧
力）が非常に狭く、しかも高圧側に偏っている為、冷媒
としてフロンを使用した場合に比べて、冷凍サイクル内
を高圧にする必要がある。[0003] In view of such circumstances, in recent years, the construction of a cooling device using a carbon dioxide refrigeration cycle using carbon dioxide (CO 2 ) as a refrigerant has been studied. The basic configuration of the carbon dioxide refrigeration cycle is almost the same as that of a vapor compression refrigeration cycle using chlorofluorocarbon as a refrigerant. However, the liquefaction region (temperature and pressure) of carbon dioxide is very narrow compared to that of chlorofluorocarbon, and it is biased toward the high pressure side. Therefore, the pressure inside the refrigeration cycle is made higher than when carbon dioxide is used as the refrigerant. There is a need.
【０００４】図１は、この様な二酸化炭素冷凍サイクル
の回路図である。コンプレッサ１から吐出した高温・高
圧の二酸化炭素は、放熱器２内を通過する間に空気との
間で熱交換を行なって温度低下する。この様にして温度
低下した二酸化炭素は、次いで内部熱交換器３を通過す
る間に更に温度低下し、好ましくは凝縮してから、膨張
弁４に向けて送られる。そして、この膨張弁４を通過す
る事により上記二酸化炭素は、断熱膨張する事により温
度低下し、更に好ましくは凝縮していた液体の二酸化炭
素が蒸発・気化する。この結果、上記膨張弁４の下流側
に設けた冷却器５の温度が低下する。従って、この冷却
器５部分に空気調和用の空気を流通させれば、この空気
を冷却すると共にこの空気中に含まれる水蒸気を除去し
て、冷房及び除湿を行なえる。上記冷却器５を通過し
た、未だ低温の二酸化炭素は、レシーバ６を通過してか
ら上記内部熱交換器３に送られ、この内部熱交換器３部
分で、上記放熱器２から送り出された、未だ温度が高い
二酸化炭素との間で熱交換を行なってから、再び上記コ
ンプレッサ１に戻されて圧縮される。尚、上記レシーバ
６は、このコンプレッサ１に、液体の二酸化炭素が送り
込まれるのを防止する役目を有する。FIG. 1 is a circuit diagram of such a carbon dioxide refrigeration cycle. The high-temperature and high-pressure carbon dioxide discharged from the compressor 1 exchanges heat with the air while passing through the radiator 2 to lower the temperature. The carbon dioxide whose temperature has been reduced in this way is further reduced in temperature while passing through the internal heat exchanger 3 and is preferably condensed before being sent to the expansion valve 4. The temperature of the carbon dioxide is reduced by adiabatic expansion by passing through the expansion valve 4, and more preferably, the condensed liquid carbon dioxide is evaporated and vaporized. As a result, the temperature of the cooler 5 provided downstream of the expansion valve 4 decreases. Therefore, if air for air conditioning is allowed to flow through the cooler 5, the air can be cooled and the water vapor contained in the air can be removed to perform cooling and dehumidification. The still low-temperature carbon dioxide that has passed through the cooler 5 is sent to the internal heat exchanger 3 after passing through the receiver 6, and is sent out of the radiator 2 at the internal heat exchanger 3. After performing heat exchange with carbon dioxide still high in temperature, it is returned to the compressor 1 again and compressed. The receiver 6 has a function of preventing liquid carbon dioxide from being sent to the compressor 1.
【０００５】上述の様な二酸化炭素冷凍サイクル内の圧
力は、上記コンプレッサ１の吐出口近傍の高圧部分で８
０〜１１０kg/cm2abs 程度に達し、このコンプレッサ１
の吸入口近傍の低圧部分でも凡そ３５kg/cm2abs 程度に
達する。この圧力は、それぞれが１５〜２０kg/cm2abs
、３kg/cm2abs 程度である、フロンを冷媒とした蒸気
圧縮式冷凍機内の圧力に比べて遥かに高い。この様に、
冷媒の圧力が高い為、二酸化炭素冷凍サイクルを構成す
る熱交換器である、上記放熱器２、内部熱交換器３、冷
却器５を構成する伝熱管内の流路は、フロンを冷媒とし
た蒸気圧縮式冷凍機を構成する熱交換器の伝熱管内の流
路に比べて狭い。この理由は、冷媒の圧力が高く、単位
体積当りの熱容量が多く、コンプレッサ１から吐出する
二酸化炭素の量を少なくできる為と、耐圧性を確保する
為とである。The pressure in the carbon dioxide refrigeration cycle as described above is 8 at the high pressure portion near the discharge port of the compressor 1.
0-110kg / cm 2 abs, this compressor 1
Even in the low pressure area near the suction port, the pressure reaches about 35 kg / cm 2 abs. This pressure is 15-20 kg / cm 2 abs each
The pressure is about 3 kg / cm 2 abs, which is much higher than the pressure in a vapor compression refrigerator using Freon as a refrigerant. Like this
Since the pressure of the refrigerant is high, the flow paths in the heat transfer tubes that constitute the radiator 2, the internal heat exchanger 3, and the cooler 5, which are the heat exchangers that constitute the carbon dioxide refrigeration cycle, use Freon as the refrigerant. It is narrower than the flow path in the heat transfer tube of the heat exchanger that constitutes the vapor compression refrigerator. The reason is that the pressure of the refrigerant is high, the heat capacity per unit volume is large, the amount of carbon dioxide discharged from the compressor 1 can be reduced, and the pressure resistance is ensured.
【０００６】図２に、上述の様な二酸化炭素冷凍サイク
ルに組み込む熱交換器を構成する伝熱管７の１例を示し
ている。この伝熱管７は、アルミニウム合金の一体押し
出し成形により造るもので、幅寸法×厚さ寸法は、例え
ば１３mm×２mm程度である。この様な伝熱管７は、例え
ば長尺なものを蛇行させて、一端から他端に二酸化炭素
を流す様に構成したり、或は所定寸法に切断した複数本
の伝熱管の一端を入口側ヘッダに、他端を出口側ヘッダ
に、それぞれ接続し、この入口側ヘッダから出口側ヘッ
ダに向けて上記複数本の伝熱管内に二酸化炭素を流す様
に構成する。FIG. 2 shows an example of a heat transfer tube 7 constituting a heat exchanger incorporated in the above-described carbon dioxide refrigeration cycle. The heat transfer tube 7 is made by integral extrusion of an aluminum alloy, and the width × thickness is, for example, about 13 mm × 2 mm. Such a heat transfer tube 7 may be configured, for example, by meandering a long one to flow carbon dioxide from one end to the other end, or by connecting one end of a plurality of heat transfer tubes cut to a predetermined size to the inlet side. The other end is connected to the header, and the other end is connected to the outlet header, and carbon dioxide is caused to flow through the plurality of heat transfer tubes from the inlet header to the outlet header.
【０００７】[0007]
【発明が解決しようとする課題】冷凍サイクル内には、
コンプレッサ１を潤滑する為の潤滑油が冷媒と共に流通
するが、冷媒として二酸化炭素を使用した場合には、フ
ロンを使用した場合とは異なり、冷媒中に潤滑油が溶け
込まない。従って、潤滑油は冷媒である二酸化炭素とは
相を分けた状態で、二酸化炭素冷凍サイクル内を流通す
る。この為、一部の潤滑油が、二酸化炭素冷凍サイクル
に組み込む熱交換器を構成する伝熱管７の内面に付着す
る事が避けられない。この伝達管７を構成するアルミニ
ウム合金自体は、潤滑油により濡れ易い（接触角が小さ
い）為、この潤滑油は上記伝熱管７の内面に油膜を形成
する。SUMMARY OF THE INVENTION In a refrigeration cycle,
The lubricating oil for lubricating the compressor 1 flows together with the refrigerant. However, when carbon dioxide is used as the refrigerant, the lubricating oil does not dissolve in the refrigerant unlike the case where Freon is used. Therefore, the lubricating oil flows in the carbon dioxide refrigeration cycle in a state where the lubricating oil is separated from the carbon dioxide as the refrigerant. Therefore, it is inevitable that a part of the lubricating oil adheres to the inner surface of the heat transfer tube 7 constituting the heat exchanger incorporated in the carbon dioxide refrigeration cycle. The aluminum alloy itself forming the transfer tube 7 is easily wetted by the lubricating oil (the contact angle is small), and therefore the lubricating oil forms an oil film on the inner surface of the heat transfer tube 7.
【０００８】この様にして伝熱管７の内面に形成された
油膜は、この伝熱管７の内部を流れる二酸化炭素と、こ
の伝熱管７との間の熱交換に対する抵抗になる。又、こ
の伝熱管７の流路面積自体小さいので、上記油膜が形成
される事に伴う、この流路面積の減少割合が大きくな
り、上記伝熱管７内を二酸化炭素が流れる事に対する抵
抗が大きくなる。これらにより、この伝熱管７により構
成した熱交換器の性能が劣化する。本発明の二酸化炭素
冷凍サイクル用熱交換器は、この様な事情に鑑みて発明
したものである。[0008] The oil film thus formed on the inner surface of the heat transfer tube 7 serves as a resistance to heat exchange between the carbon dioxide flowing inside the heat transfer tube 7 and the heat transfer tube 7. Further, since the flow path area itself of the heat transfer tube 7 is small, the rate of decrease in the flow path area due to the formation of the oil film becomes large, and the resistance to the flow of carbon dioxide through the heat transfer tube 7 becomes large. Become. As a result, the performance of the heat exchanger constituted by the heat transfer tubes 7 deteriorates. The heat exchanger for a carbon dioxide refrigeration cycle of the present invention was invented in view of such circumstances.
【０００９】[0009]
【課題を解決するための手段】本発明の二酸化炭素冷凍
サイクル用熱交換器は、扁平管状で複数の仕切壁部によ
り仕切られた複数の流路を内部に有する伝熱管を有し、
この伝熱管内の流路を流れる二酸化炭素とこの伝熱管外
を流れる空気との間で熱交換を行なわせるものである。
特に、本発明の二酸化炭素冷凍サイクル用熱交換器に於
いては、上記各流路の内面に、上記二酸化炭素と共にこ
れら各流路内を流れる潤滑油を弾く皮膜を形成してい
る。A heat exchanger for a carbon dioxide refrigeration cycle according to the present invention has a heat transfer tube having a flat tubular shape and a plurality of flow paths partitioned by a plurality of partition walls therein.
The heat exchange is performed between carbon dioxide flowing through the flow path inside the heat transfer tube and air flowing outside the heat transfer tube.
In particular, in the heat exchanger for a carbon dioxide refrigeration cycle of the present invention, a film that repels the lubricating oil flowing in each of these flow paths together with the carbon dioxide is formed on the inner surface of each of the flow paths.
【００１０】[0010]
【作用】上述の様に構成する本発明の二酸化炭素冷凍サ
イクル用熱交換器によれば、伝熱管内に油膜が形成され
る事を防止して、この伝熱管内を流れる二酸化炭素と伝
熱管との間の熱伝達を良好にすると共に、この伝熱管内
を二酸化炭素が流れる事に対する抵抗も低く抑える事が
できる。According to the heat exchanger for a carbon dioxide refrigeration cycle of the present invention constructed as described above, an oil film is prevented from being formed in the heat transfer tube, and the carbon dioxide flowing through the heat transfer tube and the heat transfer tube are prevented. And the resistance to the flow of carbon dioxide through the heat transfer tube can be reduced.
【００１１】[0011]
【発明の実施の形態】本発明の二酸化炭素冷凍サイクル
用熱交換器は、図１に示した様な二酸化炭素冷凍サイク
ルを構成する熱交換器である、放熱器２、内部熱交換器
３、冷却器５の何れかとして実施する。この熱交換器に
は、アルミニウム合金の一体押し出し成形により造っ
た、図２に示す様な断面形状を有する伝熱管７を１乃至
複数本組み込む。即ち、この伝熱管７により熱交換器を
構成するには、例えば図３に示す様に、長尺な伝熱管７
を蛇行させて、一端から他端に二酸化炭素を流す様に構
成したり、或は図４に示す様に、所定寸法に切断した複
数本の伝熱管７、７の一端を入口側ヘッダ８に、他端を
出口側ヘッダ９に、それぞれ接続し、この入口側ヘッダ
８から出口側ヘッダ９に向けて上記複数本の伝熱管７、
７内に二酸化炭素を流す様に構成する。何れの場合で
も、伝熱管７、７にコルゲート型のフィン１０、１０を
添設して、これら各伝熱管７、７と、これら各伝熱管
７、７外を流れる空気との間での熱交換を効率良く行な
わせる様にする。但し、内部熱交換器３として実施する
場合には、放熱器２から送り出された高温の二酸化炭素
を流す伝熱管と、レシーバ６から送り出された低温の二
酸化炭素を流す伝熱管とを重ね合わせる。DESCRIPTION OF THE PREFERRED EMBODIMENTS A heat exchanger for a carbon dioxide refrigeration cycle according to the present invention is a heat exchanger constituting a carbon dioxide refrigeration cycle as shown in FIG. This is performed as one of the coolers 5. This heat exchanger incorporates one or more heat transfer tubes 7 formed by integral extrusion of an aluminum alloy and having a sectional shape as shown in FIG. That is, in order to form a heat exchanger by using the heat transfer tubes 7, for example, as shown in FIG.
, And flow carbon dioxide from one end to the other end, or as shown in FIG. 4, connect one end of a plurality of heat transfer tubes 7, 7 cut to a predetermined size to the inlet side header 8. The other end is connected to the outlet header 9, and the plurality of heat transfer tubes 7 are connected from the inlet header 8 to the outlet header 9.
7 is configured to flow carbon dioxide. In any case, corrugated fins 10, 10 are added to the heat transfer tubes 7, 7, so that heat between the heat transfer tubes 7, 7 and the air flowing outside the heat transfer tubes 7, 7 is generated. Make the exchange efficient. However, when the heat exchanger is implemented as the internal heat exchanger 3, the heat transfer tube through which the high-temperature carbon dioxide sent from the radiator 2 flows and the heat transfer tube through which the low-temperature carbon dioxide sent from the receiver 6 flows are overlapped.
【００１２】上述の様な熱交換器を構成する伝熱管７、
７内に設けた複数本の流路１１、１１の内面には、冷媒
である二酸化炭素と共にこれら各流路１１、１１内を流
れる潤滑油を弾く皮膜を形成している。この皮膜の材質
としては、必要な撥油性、耐久性（耐剥離性）、耐熱性
（１００〜２００℃）を有する材料であれば何れも使用
できるが、例えば弗素樹脂のコーティング層が、好まし
く使用できる。又、この様な弗素樹脂のコーティング層
としては、東京シリコーン株式会社が提供している各種
弗素樹脂コーティング膜が使用可能で、この中でも特
に、変性塗料系のものが、好ましく使用できる。又、同
社が出願した特願平２−１０００５号（特開平３−２１
５５７０号）に係るもののうち、弗素樹脂系のものは、
上記した条件を満たす皮膜として利用可能である。更に
は、アサヒ硝子株式会社が撥水撥油加工剤として販売し
ている「アサヒガード」、離型剤として販売している
「モールドスパット」（何れも商品名）等も、使用可能
である。The heat transfer tubes 7 constituting the heat exchanger as described above,
On the inner surface of the plurality of flow paths 11 provided in 7, a film is formed which repels the lubricating oil flowing in each of the flow paths 11, 11 together with carbon dioxide as a refrigerant. As the material of this film, any material can be used as long as it has the necessary oil repellency, durability (peeling resistance), and heat resistance (100 to 200 ° C.). For example, a fluorine resin coating layer is preferably used. it can. Further, as such a fluorine resin coating layer, various fluorine resin coating films provided by Tokyo Silicone Co., Ltd. can be used, and among them, a modified paint-based coating film can be preferably used. In addition, Japanese Patent Application No. 2-10005 filed by the company (Japanese Unexamined Patent Application Publication No.
No. 5570), fluororesin-based resins include:
It can be used as a film satisfying the above conditions. Further, "Asahi Guard" sold as a water / oil repellent by Asahi Glass Co., Ltd., "Mold Spat" (all trade names) sold as a release agent, and the like can also be used.
【００１３】尚、上記各流路１１、１１の内面に上記皮
膜を形成するには、材料となる液体をこれら各流路１
１、１１内に流し込んで、この液体をこれら各流路１
１、１１の内面に付着させた後、この液体を乾燥させ
る。この乾燥の際、必要に応じて伝熱管７全体を加熱す
る。この様な方法によれば、断面積が狭い、上記各流路
１１、１１の内面に、厚さが１０μｍ以下の撥油性皮膜
を均一に形成できる。In order to form the film on the inner surface of each of the flow paths 11, 11, a liquid as a material is applied to each of the flow paths 1 and 11.
1 and 11 and the liquid is supplied to each of these flow paths 1.
After being attached to the inner surfaces of 1, 11, this liquid is dried. During this drying, the entire heat transfer tube 7 is heated as necessary. According to such a method, an oil-repellent film having a thickness of 10 μm or less can be uniformly formed on the inner surface of each of the channels 11 having a small cross-sectional area.
【００１４】上述の様に構成する本発明の二酸化炭素冷
凍サイクル用熱交換器によれば、伝熱管７内に設けた各
流路１１、１１の表面に油膜が形成される事を防止でき
る。即ち、二酸化炭素と共にこれら各流路１１、１１内
に送り込まれた潤滑油は、上記皮膜により弾かれて油滴
となる。この結果、これら各流路１１、１１の内面に対
する潤滑油の付着強度が極く弱くなる。そして、上記油
滴が、これら各流路１１、１１内を流れる二酸化炭素に
押されて、上記各流路１１、１１外に排出される。この
結果、これら各流路１１、１１の内面に油膜が形成され
る事がなくなり、上記伝熱管７内を流れる二酸化炭素と
伝熱管７との間の熱伝達を良好にすると共に、この伝熱
管７内を二酸化炭素が流れる事に対する抵抗も低く抑え
る事ができる。即ち、上記皮膜の厚さは、１０μｍ以下
と、油膜の厚さ（数十乃至百μｍ）に比べて遥かに薄い
為、この皮膜が熱伝達に対する抵抗になる事は殆どな
く、上記各流路１１、１１の断面積を狭くする事も殆ど
ない。これらにより、二酸化炭素冷凍サイクル用熱交換
器の性能向上を図れる。According to the heat exchanger for a carbon dioxide refrigeration cycle of the present invention configured as described above, it is possible to prevent an oil film from being formed on the surfaces of the channels 11 provided in the heat transfer tube 7. That is, the lubricating oil sent into each of the flow paths 11, 11 together with the carbon dioxide is repelled by the above-mentioned film to become oil droplets. As a result, the adhesion strength of the lubricating oil to the inner surface of each of the flow paths 11, 11 becomes extremely weak. Then, the oil droplets are pushed out by the carbon dioxide flowing in each of the flow paths 11, 11 and discharged out of the respective flow paths 11, 11. As a result, no oil film is formed on the inner surface of each of the flow paths 11, 11, and the heat transfer between the carbon dioxide flowing in the heat transfer tube 7 and the heat transfer tube 7 is improved, and the heat transfer tube 7 The resistance to the flow of carbon dioxide in the inside 7 can also be kept low. That is, the thickness of the film is 10 μm or less, which is much smaller than the thickness of the oil film (several tens to hundreds of μm). There is almost no reduction in the sectional area of 11,11. Thus, the performance of the heat exchanger for the carbon dioxide refrigeration cycle can be improved.
【００１５】[0015]
【発明の効果】本発明は、上述の様に構成し作用する
為、二酸化炭素冷凍サイクル用熱交換器の性能向上によ
り、二酸化炭素冷凍サイクル全体としての性能向上を図
る事ができ、二酸化炭素冷凍サイクルの実現に寄与でき
る。Since the present invention is constructed and operates as described above, it is possible to improve the performance of the entire carbon dioxide refrigeration cycle by improving the performance of the heat exchanger for the carbon dioxide refrigeration cycle. It can contribute to the realization of the cycle.
【図１】二酸化炭素冷凍サイクルの回路図。FIG. 1 is a circuit diagram of a carbon dioxide refrigeration cycle.
【図２】熱交換器を構成する伝熱管の拡大断面図。FIG. 2 is an enlarged sectional view of a heat transfer tube constituting the heat exchanger.
【図３】この伝熱管を使用して構成した熱交換器の第１
例を示す、略正面図。FIG. 3 is a first view of a heat exchanger constituted by using the heat transfer tube.
A schematic front view showing an example.
【図４】同第２例を示す略正面図。FIG. 4 is a schematic front view showing the second example.
１ コンプレッサ ２ 放熱器 ３ 内部熱交換器 ４ 膨張弁 ５ 冷却器 ６ レシーバ ７ 伝熱管 ８ 入口側ヘッダ ９ 出口側ヘッダ １０ フィン １１ 流路 DESCRIPTION OF SYMBOLS 1 Compressor 2 Radiator 3 Internal heat exchanger 4 Expansion valve 5 Cooler 6 Receiver 7 Heat transfer tube 8 Inlet side header 9 Outlet side header 10 Fin 11 Flow path
───────────────────────────────────────────────────── フロントページの続き (72)発明者 吉田 千鶴子 東京都中野区南台５丁目24番15号 カルソ ニック株式会社内 Ｆターム(参考） 4J038 CD091 NA05 PB06 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Chizuru Yoshida 5-24-15 Minamidai, Nakano-ku, Tokyo Calsonic Corporation F-term (reference) 4J038 CD091 NA05 PB06
Claims (4)
れた複数の流路を内部に有する伝熱管を有し、この伝熱
管内の流路を流れる二酸化炭素とこの伝熱管外を流れる
空気との間で熱交換を行なわせる二酸化炭素冷凍サイク
ル用熱交換器に於いて、上記各流路の内面に、上記二酸
化炭素と共にこれら各流路内を流れる潤滑油を弾く皮膜
を形成した事を特徴とする二酸化炭素冷凍サイクル用熱
交換器。1. A heat transfer tube having a plurality of flow passages therein, each of which has a flat tubular shape and is partitioned by a plurality of partition walls, wherein carbon dioxide flows through the flow passage inside the heat transfer tube and air flows outside the heat transfer tube. In the heat exchanger for a carbon dioxide refrigeration cycle for performing heat exchange with the above, a film that repels the lubricating oil flowing in each of the flow paths together with the carbon dioxide is formed on the inner surface of each of the flow paths. Characteristic heat exchanger for carbon dioxide refrigeration cycle.
る、請求項１に記載した二酸化炭素冷凍サイクル用熱交
換器。2. The heat exchanger for a carbon dioxide refrigeration cycle according to claim 1, wherein the coating is a coating layer of a fluorine resin.
項１〜２の何れかに記載した二酸化炭素冷凍サイクル用
熱交換器。3. The heat exchanger for a carbon dioxide refrigeration cycle according to claim 1, wherein the thickness of the film is 10 μm or less.
し込んでこれら各流路の内面に付着させた後、この液体
を乾燥させる事により形成したものである、請求項１〜
３の何れかに記載した二酸化炭素冷凍サイクル用熱交換
器。4. The film is formed by flowing a liquid serving as a material into each of the flow paths, attaching the liquid to the inner surfaces of the flow paths, and then drying the liquid.
3. The heat exchanger for a carbon dioxide refrigeration cycle according to any one of 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21098398A JP2000046421A (en) | 1998-07-27 | 1998-07-27 | Heat exchanger for carbon dioxide refrigeration cycle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21098398A JP2000046421A (en) | 1998-07-27 | 1998-07-27 | Heat exchanger for carbon dioxide refrigeration cycle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000046421A true JP2000046421A (en) | 2000-02-18 |
Family
ID=16598377
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21098398A Pending JP2000046421A (en) | 1998-07-27 | 1998-07-27 | Heat exchanger for carbon dioxide refrigeration cycle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000046421A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001061263A1 (en) * | 2000-02-15 | 2001-08-23 | Zexel Valeo Climate Control Corporation | Heat exchanger |
| WO2002010655A1 (en) * | 2000-08-01 | 2002-02-07 | Matsushita Electric Industrial Co., Ltd. | Refrigeration cycle device |
| WO2002066907A1 (en) * | 2001-02-21 | 2002-08-29 | Matsushita Electric Industrial Co., Ltd. | Refrigeration cycle device |
| GB2399623A (en) * | 2003-03-19 | 2004-09-22 | Calsonic Kansei Uk Ltd | Flat tube heat exchanger for a vehicle air conditioning system |
-
1998
- 1998-07-27 JP JP21098398A patent/JP2000046421A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001061263A1 (en) * | 2000-02-15 | 2001-08-23 | Zexel Valeo Climate Control Corporation | Heat exchanger |
| WO2002010655A1 (en) * | 2000-08-01 | 2002-02-07 | Matsushita Electric Industrial Co., Ltd. | Refrigeration cycle device |
| US6962059B2 (en) | 2000-08-01 | 2005-11-08 | Matsushita Electric Industrial Co., Ltd. | Refrigerating cycle device |
| EP1306629A4 (en) * | 2000-08-01 | 2006-11-02 | Matsushita Electric Ind Co Ltd | Refrigeration cycle device |
| WO2002066907A1 (en) * | 2001-02-21 | 2002-08-29 | Matsushita Electric Industrial Co., Ltd. | Refrigeration cycle device |
| US6871511B2 (en) | 2001-02-21 | 2005-03-29 | Matsushita Electric Industrial Co., Ltd. | Refrigeration-cycle equipment |
| GB2399623A (en) * | 2003-03-19 | 2004-09-22 | Calsonic Kansei Uk Ltd | Flat tube heat exchanger for a vehicle air conditioning system |
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