Patent Description:
Conventionally, a heat exchanging apparatus of the falling liquid film type is known for cooling or heating heat exchange fluid by exchanging heat between a heat transfer medium (refrigerant or heat medium) flowing through a heat transfer medium circulation pipe and the heat exchange fluid while the heat exchange fluid flows down by its dead weight along an outer surface of the heat exchange fluid circulation pipe in the form of a liquid film. For instance, refer to Patent Document <NUM>.

However, the conventional heat exchanging apparatus of the falling liquid film type has a problem that a case to which the heat exchange fluid circulation pipe is attached makes one difficult to clean and maintain the heat exchange fluid circulation pipe.

Under such circumstances, Patent Document <NUM> proposes a heat exchanging apparatus in which one of side walls of a case for housing a heat exchange unit including a heat exchange fluid circulation pipe is open, the heat exchange unit is attached to a lid member for opening and closing an opening of the case, and the lid member is slid horizontally together with the heat exchange unit to be taken out of the case when cleaning or maintaining the heat exchange fluid circulation pipe. According to this heat exchanging apparatus, the heat exchange fluid circulation pipe of the heat exchange unit taken out from the case can be easily cleaned and maintained. Patent Document <NUM> discloses a configuration in which discharge outlets (<NUM>, 43a) for a fluid subjected to heat exchange that are for discharging the fluid subjected to heat exchange that drips into a case are provided in a side wall that is in the same direction as the opening direction of a heat transfer medium inlet and a heat transfer medium outlet in the case. Utility Model Document <NUM> discloses features wherein the case (<NUM>) is constructed as a rectangular box, the top surface of which is open, a cutout (3a) that is open at the top is also formed in the top end of a side wall (<NUM>) that is in the same direction as the opening direction of a fluid inlet and a fluid outlet in the case, and the fluid inlet and the fluid outlet face the cutout. Utility Model Document <NUM> discloses a feature wherein cutouts of the same dimensions and the same shape that are open at the top are formed in the top ends of each of a pair of side walls that are in the same direction and the opposite direction as the opening direction of a fluid inlet (<NUM>) and a fluid outlet (<NUM>) in a case (l), and the fluid inlet and the fluid outlet face either one of the cutouts.

In the heat exchanging apparatus proposed in Patent Document <NUM>, a heat transfer medium inlet and a heat transfer medium outlet at both ends of the heat exchange fluid circulation pipe are open in the same direction, and a heat exchange fluid discharge port is formed on the case for discharging the heat exchange fluid having dropped down in the case to the outside of the case.

The heat exchanging apparatus adopting the above-described configuration has been made available in two types. One includes a heat exchange fluid discharge port formed on the opposite side of the case to the opening direction of the heat transfer medium inlet and the heat transfer medium outlet of the heat exchange fluid circulation pipe, and the other includes a heat exchange fluid discharge port formed on the underside of the case. However, when the discharge port is formed on the underside of the case, the pipe should pass under the apparatus, so that long legs to be necessarily provided at the bottom of the apparatus increase the cost of the heat exchanging apparatus. And at a low inflow height of the heat exchange fluid, the difficulty to install the apparatus and the necessity of pumping up and then allowing the heat exchange fluid to flow in should increase piping man-hours and cost. Further, if the discharge port is formed on the opposite side to the heat transfer medium inlet and the heat transfer medium outlet, there has been a problem of increase in installation man-hours and piping man-hours depending on given piping conditions at the installation site, thereby leading to cost increase.

Moreover, because of the necessity to seal the lid member and a peripheral edge of the opening of the case with a sealing material when the lid member is closed, there have been also concerns about an increase in the number of parts and leakage of the heat exchange fluid from the case owing to deterioration of the sealing material.

The present invention has been made in view of the above problems, and an object thereof is to provide one type of heat exchanging apparatus that can adapt for installation of the heat exchange fluid discharge port and the heat transfer medium inlet and outlet in the same direction or in different directions depending on given piping conditions at the installation site and reduce in overall height of the apparatus so as to reduce the number of steps required for manufacturing, management and installation for cost reduction, and to realize reduction in the number of parts and simplification of maintenance by eliminating sealing materials.

In order to achieve the above object, the present invention is a heat exchanging apparatus (<NUM>) according to claim <NUM>.

According to the present invention, if the opening direction of the heat transfer medium inlet and the heat transfer medium outlet of the heat transfer medium circulation pipe is incompatible with the opening direction of the heat exchange fluid discharge port formed on the case under given piping conditions at the installation site of the heat exchanging apparatus, the opening direction of the heat transfer medium inlet and the heat transfer medium outlet and the opening direction of the heat exchange fluid discharge port formed on the case can be adjusted to meet the piping conditions at the installation site by taking out the heat exchange unit upward from the case, rotating it <NUM> degrees around the vertical axis, and then storing it in the case. Therefore, only one type of heat exchanging apparatus needs to be made available, whereby man-hours for manufacturing, managing, and installing the heat exchanging apparatus can be reduced for cost reduction.

In addition, no sealing material is required for sealing between the case and the heat exchange unit, realizing reduction in the number of parts and simplification of maintenance.

Here, in the above-described heat exchanging apparatus (<NUM>), the case (<NUM>) may be configured as a rectangular box open upward, and a notch (<NUM>) of the same size and shape open upward may be formed at each of upper ends of a pair of opposite side walls (10A, 10B) of the case (<NUM>) respectively in the same direction as and in the opposite direction to the opening direction of the heat transfer medium inlet (21a) and the heat transfer medium outlet (21b) so that the heat transfer medium inlet (21a) and the heat transfer medium outlet (21b) can face either one of the notches (<NUM>).

The above-described configuration enables the heat transfer medium inlet and the heat transfer medium outlet of the heat transfer medium circulation pipe provided in the heat exchange unit to face either one of the notches regardless of the housing direction of the heat exchange unit in the case. Further, the notch formed on the case is open upward so as not to prevent the heat exchange unit from being taken in and out of the case.

Moreover, in the heat exchanging apparatus (<NUM>), the heat exchange unit (<NUM>) includes the heat transfer medium circulation pipe (<NUM>) spirally wound along the vertical direction and a rectangular frame body (<NUM>) for housing and holding the heat transfer medium circulation pipe (<NUM>). The heat transfer medium inlet (21a) and the heat transfer medium outlet (21b) are open on either one of fixing plates (<NUM>) vertically attached to two opposite positions of the rectangular frame body (<NUM>). Communication holes (23a), one of which communicates with the heat exchange fluid discharge port (<NUM>), may be formed on lower sections of both fixing plates (<NUM>).

According to the above configuration, regardless of the housing direction of the heat exchange unit in the case, either one of the communication holes formed on both fixing plates communicates with the heat exchange fluid discharge port of the case. Accordingly, even if the housing direction of the heat exchange unit is changed, the heat exchange fluid falling inside the case can be reliably discharged to the outside of the case through the communication hole and the heat exchange fluid discharge port communicating with each other.

Moreover, in the heat exchanging apparatus (<NUM>), the case (<NUM>) may be provided with a guide means (<NUM>) for guiding a slide in the vertical direction when the heat exchange unit (<NUM>) is taken in and out.

According to the above configuration, when the heat exchange unit is taken in and out of the case, the heat exchange unit can be smoothly slid up and down while being guided by the guide means, so that the heat exchange unit can be taken in and out of the case stably and reliably with no rattling.

Furthermore, in the heat exchanging apparatus (<NUM>), the guide means (<NUM>) may be composed of a notch (<NUM>) formed at each two opposite positions at both ends in the longitudinal direction of two flanges (10a) formed by bending inward at a right angle upper end edges of two opposite side walls (10C, 10D) facing each other so that the fixing plate (<NUM>) can be fitted into the notch.

According to the above configuration, the guide means for guiding the slide of the heat exchange unit in the vertical direction when the heat exchange unit is taken in and out of the case can be easily composed of the notch formed on the case, into which the fixing plate is fitted.

According to the present invention, one type of heat exchanging apparatus is adaptable for different piping conditions at the installation site, thereby reducing the man-hours for manufacturing, managing, and installing the heat exchanging apparatus for cost reduction. In addition, effects of reduction in the number of parts and simplification of maintenance can be achieved by eliminating the sealing materials.

<FIG> is a perspective view of a heat exchanging apparatus according to the present invention, <FIG> is an exploded perspective view of the heat exchanging apparatus according to the present invention, <FIG> is an enlarged detailed view of part A of <FIG>, <FIG> is a front view of the heat exchange unit of the heat exchanging apparatus according to the present invention, <FIG> is a perspective view of the heat exchanging apparatus according to the present invention, of which the heat exchange unit is mounted, horizontally reversed from the state shown in <FIG>, <FIG> is a side view of the heat exchanging apparatus shown in <FIG> (namely, a view from the direction of arrow B in <FIG>), and <FIG> is an exploded perspective view of the heat exchanging apparatus shown in <FIG>. It should be noted that in <FIG>, the description of the heat transfer medium circulation pipe <NUM> is omitted in part.

The heat exchanging apparatus <NUM> according to the present invention is a heat exchanging apparatus of the falling liquid film type including as shown in <FIG> and <FIG>, a case <NUM> open upward, a heat exchange unit <NUM> housed in the case <NUM>, and a storage tank <NUM> arranged at an upper section of the case <NUM>. Heat exchange fluid stored in the storage tank <NUM> drops by its dead weight onto a heat transfer medium circulation pipe <NUM> of the heat exchange unit <NUM> so as to exchange heat between the heat exchange fluid and heat transfer medium flowing through the heat transfer medium circulation pipe <NUM>.

The case <NUM> is made of a metal plate having a low thermal conductivity such as a stainless steel plate formed into an elongated rectangular box shape, and four corners of a lower section thereof are supported by height-adjustable support legs <NUM>. It should be noted that in the following description, as shown in <FIG> and <FIG>, the longitudinal and lateral directions of the case <NUM> are referred to respectively as "left-right direction" and "front-back direction".

As shown in <FIG> and <FIG>, on each of upper ends of opposite side walls 10A, 10B on the shorter sides (namely, at both ends in the left-right direction) of the case <NUM>, a rectangular notch <NUM> of the same size and shape open upward is formed. Then, on a lower section of one of the side walls 10A (on the front side, namely at the left end, in <FIG> and <FIG>), a pipe-shaped heat exchange fluid discharge port <NUM> is formed for discharging the heat exchange fluid falling into the case <NUM> to the outside of the case <NUM> as will be described later.

Further, as shown in <FIG>, at each of upper end edges of opposite side walls 10C, 10D on the longer side (namely, at both ends in the front-rear direction) of the case <NUM>, a narrow flange 10a bent inward at a right angle is formed along the longitudinal direction (namely, along the left-right direction). Then, as shown in detail in <FIG>, a rectangular notch is formed at each two opposite positions, namely at a total of four positions, of which only two are shown in <FIG>, at both ends in the longitudinal direction (left-right direction) of both flanges 10a. Each of the notches <NUM> functions as a guide means for guiding the heat exchange unit <NUM> when the heat exchange unit <NUM> is vertically taken in and out of the case <NUM> as will be described later.

Further, as shown in <FIG>, a positioning pin <NUM> is erected in the vicinity of each of the notches <NUM> of each of the flanges 10a of the case <NUM>.

As shown in <FIG> and <FIG>, the heat exchange unit <NUM> includes the heat transfer medium circulation pipe <NUM> wound spirally (namely, in an oval ring shape) along the vertical direction and a rectangular frame body <NUM> for housing and holding the heat transfer medium circulation pipe <NUM>.

The rectangular frame <NUM> includes two left and right rectangular plate-shaped fixing plates <NUM> standing vertically, each two upper and lower horizontal bars <NUM> horizontally bridged between front ends and between rear ends of the fixing plates <NUM>, and each three vertical bars <NUM> bridged vertically at appropriate intervals in the left-right direction between the two front upper and lower horizontal bars <NUM> and between the two rear upper and lower horizontal bars <NUM>, in which the heat transfer medium circulation pipe <NUM> is housed and held.

The heat transfer medium circulation pipe <NUM> circulates a heat transfer medium such as a refrigerant (water, freon, etc.) and a heating medium (steam, etc.) inside. As shown in <FIG>. , both ends of the heat transfer medium circulation pipe <NUM> rise vertically along the inside of the side wall 10A at the left end of the case <NUM> and penetrate through one of the fixing plates <NUM> (namely, the left one) to be open on an upper section of the left fixing plate <NUM> side by side in the front-rear direction. One of the openings constitutes the heat transfer medium inlet 21a, and the other constitutes the heat transfer medium outlet 21b. As described above, the heat transfer medium inlet 21a and the heat transfer medium outlet 21b of the heat transfer medium circulation pipe <NUM> are open side by side at the same height position on the upper section of one of the fixing plates <NUM> (namely, of the left one in the illustrated example) toward the same direction (namely, to the left direction in the illustrated example). As the material of the heat transfer medium circulation pipe <NUM>, it is preferable to select copper or copper alloy having a large thermal conductivity.

Moreover, as shown in <FIG>, a notched circular communication hole 23a open downward is formed at the central part in the front-rear direction of a lower end of each of the two left and right fixing plates <NUM>. It should be noted that when the heat exchange unit <NUM> is housed in the case <NUM>, one of the two communication holes 23a (namely, the left one in the illustrated example) communicates with the heat exchange fluid discharge port <NUM> formed on one of the side plates 10A of the case <NUM> (namely, on the left one in the illustrated example).

The storage tank <NUM> is a rectangular tray-shaped container open upward, in which the heat exchange fluid is stored. It should be noted that a large number of small hole-shaped dripping holes are formed on the bottom surface of the storage tank <NUM> although they are not shown in the figure.

Here, as shown in <FIG>, each of upper end edges of front and rear side walls 30A, 30B opposed to each other on the longer side of the storage tank <NUM> is bent outward at a right angle to form a flange 30a. Positioning holes <NUM> are formed on both left and right ends of each flange 30a (namely, at two left and right positions corresponding to the positioning pins <NUM> erected on each flange 10a of the case <NUM>).

Then, from the state shown in <FIG>, the heat exchange unit <NUM> of the heat exchanging apparatus <NUM> is mounted from above and thus housed in the case <NUM>. At this time, the left and right fixing plates <NUM> of the heat exchange unit <NUM> are inserted and fitted into the notches <NUM> serving as the guide means formed at each two opposite positions of the two flanges 10a of the case <NUM>. This enables the heat exchange unit <NUM> to smoothly drop down into the case <NUM> with no rattling while being guided by the notch <NUM> so as to be accurately housed in a proper position. In the state where the heat exchange unit <NUM> is housed in the case <NUM> in this manner, as shown in <FIG>, the heat transfer medium inlet 21a and the heat transfer medium outlet 21b of the heat transfer medium circulation pipe <NUM>, both of which are open on one of the fixing plates <NUM> (namely, on the left one) of the heat exchange unit <NUM>, face the notch <NUM> formed on the upper section of the left side wall 10A of the case <NUM>.

After that, the heat exchanging apparatus <NUM> is assembled upon placement of the flange 30a of the storage tank <NUM> on the flange 10a of the case <NUM>. At this time, the four total positioning pins <NUM> formed on the flanges 10a of the case <NUM> are fitted into the four total positioning holes <NUM> formed on the flanges 30a of the storage tank <NUM>. This enables the storage tank <NUM> to be placed while being accurately positioned on the upper section of the case <NUM>.

In the examples shown in <FIG> and <FIG>, the heat exchange fluid discharge port <NUM> of the case <NUM> is open in the same direction as the opening direction (namely, leftward) of the heat transfer medium inlet 21a and the heat transfer medium outlet 21b of the heat transfer medium circulation pipe <NUM> provided in the heat exchange unit <NUM>.

In the heat exchanging apparatus <NUM> configured as described above, when the heat exchange fluid stored in the storage tank <NUM> drops onto the heat exchange unit <NUM> in the case <NUM> by its dead weight through the large number of dripping holes (not shown in the figure) formed on the bottom surface of the storage tank <NUM>, the heat exchange fluid flows down in the form of a liquid film along the outer surface of the heat transfer medium circulation pipe <NUM> of the heat exchange unit <NUM>. Here, in the heat transfer medium circulation pipe <NUM> of the heat exchange unit <NUM>, the heat transfer medium circulates in the heat transfer medium circulation pipe <NUM> in the manner that the heat transfer medium flows in from the heat transfer medium inlet 21a, flows spirally from downward to upward in the heat transfer medium circulation pipe <NUM>, and is then discharged from the heat transfer medium outlet 21b to the outside of the case <NUM>.

Therefore, in the process of flowing down in the form of a liquid film along the outer surface of the heat transfer medium circulation pipe <NUM>, the heat exchange fluid is cooled or heated by exchanging heat with the heat transfer medium flowing through the heat transfer medium circulation pipe <NUM> and eventually falls down to the bottom of the case <NUM>.

As described above, the heat exchange fluid having exchanged heat with the heat transfer medium and fallen down to the bottom of the case <NUM> is discharged to the outside of the case <NUM> through the communication hole 23a of the fixing plate <NUM> and the heat exchange fluid discharge port <NUM> of the case <NUM> communicating with each other.

Here, depending on given piping conditions at the installation site of the heat exchanging apparatus <NUM>, it may be convenient that the opening direction of the heat transfer medium inlet 21a and the heat transfer medium outlet 21b of the heat transfer medium circulation pipe <NUM> is opposed to the opening direction of the heat exchange fluid discharge port <NUM> formed on the case <NUM>.

In the above case, the heat exchange unit <NUM> is slid upward to be taken out from the case <NUM> as shown in <FIG>, and then the heat exchange unit <NUM> having taken out is rotated by <NUM> degrees around the vertical axis to be horizontally reversed as shown in <FIG>. Then, the opening direction of the heat transfer medium inlet 21a and the heat transfer medium outlet 21b of the heat transfer medium circulation pipe <NUM> in the heat exchange unit <NUM> is opposed to the opening direction of the heat transfer fluid discharge port <NUM> formed on the case <NUM>. In other words, as shown in <FIG>, while the heat transfer medium inlet 21a and the heat transfer medium outlet 21b of the heat transfer medium circulation pipe <NUM> are open so as to face the notch <NUM> formed on the right side wall 10B of the case <NUM>, the heat exchange fluid discharge port <NUM> formed on the case <NUM> is open on the left side of the case <NUM>.

The assembly of the heat exchanging apparatus <NUM> with the heat exchange unit <NUM> horizontally reversed is completed in the manner as described above, namely, by taking out the heat exchange unit <NUM> from the case <NUM> to be horizontally reversed, dropping down and then housing the heat exchange unit <NUM> in the case <NUM> as shown in <FIG>, and then installing the storage tank <NUM> on the upper section of the case <NUM>. In this manner, owing to the communication holes 23a formed on both left and right fixing plates <NUM>, either one of these communication holes 23a communicates with the heat exchange fluid discharge port <NUM> of the case <NUM> in the heat exchanging apparatus <NUM> provided with the horizontally reversed heat exchange unit <NUM>. Therefore, even when the heat exchange unit <NUM> is horizontally reversed, the heat exchange fluid falling into the case <NUM> can be discharged to the outside through the communication hole 23a on the fixing plate <NUM> and the heat exchange fluid discharge port <NUM> on the case <NUM>.

And also in the heat exchanging apparatus <NUM> provided with the horizontally reversed heat exchange unit <NUM>, in the manner as described above, when the heat exchange fluid stored in the storage tank <NUM> drops onto the heat exchange unit <NUM> by its dead weight inside the case <NUM> through the large number of dripping holes (not shown in the figure) formed on the bottom surface of the storage tank <NUM>, the heat exchange fluid is cooled or heated by exchanging heat with the heat transfer medium flowing through the heat transfer medium circulation pipe <NUM> in the process of flowing down in the form of a liquid film along the outer surface of the heat transfer medium circulation pipe <NUM> of the heat exchange unit <NUM>.

As described above, according to the heat exchanging apparatus <NUM> of the present invention, if the opening direction of the heat transfer medium inlet 21a and the heat transfer medium outlet 21b of the heat transfer medium circulation pipe <NUM> is incompatible with the opening direction of the heat exchange fluid discharge port <NUM> formed on the case <NUM> under given piping conditions at the installation site of the heat exchanging apparatus <NUM>, the opening direction of the heat transfer medium inlet 21a and the heat transfer medium outlet 21b and the opening direction of the heat exchange fluid discharge port <NUM> formed on the case <NUM> can be adjusted to meet the piping conditions at the installation site by taking out the heat exchange unit <NUM> upward from the case <NUM>, rotating it <NUM> degrees around the vertical axis, and then storing it in the case <NUM>. Accordingly, only one type of heat exchanging apparatus <NUM> needs to be made available, whereby man-hours for manufacturing, managing, and installing the heat exchanging apparatus <NUM> can be reduced for cost reduction.

In addition, no sealing material is required for sealing between the case <NUM> and the heat exchange unit <NUM>, realizing reduction in the number of parts and simplification of maintenance.

Moreover, in the present embodiment, in the case <NUM>, the notch <NUM> of the same size and shape open upward is formed at each of the upper ends of the pair of the opposite side walls 10A, 10B respectively in the same direction as and in the opposite direction to the opening direction of the heat transfer medium inlet 21a and the heat transfer medium outlet 21b so that the heat transfer medium inlet 21a and the heat transfer medium outlet 21b can face either one of the notches <NUM>. This can achieve the effects as follows. That is, regardless of the housing direction of the heat exchange unit <NUM> in the case <NUM>, the heat transfer medium inlet 21a and the heat transfer medium outlet 21b of the heat transfer medium circulation pipe <NUM> provided in the heat exchange unit <NUM> can face either one of the notches on the case <NUM>. Further, the notch <NUM> formed on the case <NUM> open upward never prevents the heat exchange unit <NUM> from being taken in and out of the case <NUM>.

Moreover, in the present embodiment, the heat transfer medium inlet 21a and the heat transfer medium outlet 21b of the heat transfer medium circulation pipe <NUM> are open on one of the pair of the fixing plates <NUM> provided in the heat exchange unit <NUM>, and the communication holes 23a, one of which communicates with the heat exchange fluid discharge port <NUM> on the case <NUM>, are formed on the lower sections of both fixing plates <NUM>. This can achieve the effects as follows. That is, regardless of the housing direction of the heat exchange unit <NUM> in the case <NUM>, one of the communication holes 23a formed on both fixing plates <NUM> communicates with the heat exchange fluid discharge port <NUM> on the case. Thus, even if the housing direction of the heat exchange unit <NUM> is changed, the heat exchange fluid falling inside the case <NUM> can be reliably discharged to the outside of the case <NUM> through the communication hole 23a and the heat exchange fluid discharge port <NUM> communicating with each other.

Moreover, in the present embodiment, the notch <NUM> serving as the guide means is formed at the flange 10a of the case <NUM> for guiding a slide in the vertical direction when the heat exchange unit <NUM> is taken in and out, so that when taking the heat exchange unit <NUM> in and out of the case <NUM>, the heat exchange unit <NUM> can smoothly slide up and down while being guided by the notch <NUM>. Therefore, the heat exchange unit <NUM> can be taken in and out of the case <NUM> stably and reliably with no rattling. The notch <NUM> serving as the guiding means can be easily formed at the flange 10a of the case <NUM>.

Claim 1:
A heat exchanging apparatus (<NUM>) comprising:
a case (<NUM>) open upward;
a heat exchange unit (<NUM>) housed in the case (<NUM>); and
a storage tank (<NUM>) arranged at an upper section of the case (<NUM>),
wherein heat exchange fluid stored in the storage tank (<NUM>) drops onto a heat transfer medium circulation pipe (<NUM>) of the heat exchange unit (<NUM>) by dead weight to exchange heat between the heat exchange fluid and a heat transfer medium, the heat transfer medium flowing through the heat transfer medium circulation pipe (<NUM>),
wherein a heat transfer medium inlet (21a) and a heat transfer medium outlet (21b) are open in a same direction at both ends of the heat transfer medium circulation pipe (<NUM>), and a heat exchange fluid discharge port (<NUM>) for discharging the heat exchange fluid having dropped in the case (<NUM>) is formed on a side wall (10A) of the case (<NUM>) either in the same direction as or in the opposite direction to an opening direction of the heat transfer medium inlet (21a) and the heat transfer medium outlet (21b) so that the heat exchange unit (<NUM>) can be vertically taken in and out of the case (<NUM>),
wherein the heat transfer medium circulation pipe (<NUM>) is wound spirally along the vertical direction and wherein the heat exchanger unit (<NUM>) comprises a rectangular frame (<NUM>) for housing and holding the heat transfer medium circulation pipe (<NUM>),
wherein the heat transfer medium inlet (21a) and the heat transfer medium outlet (21b) are open on one of fixing plates (<NUM>) vertically installed to two opposite positions of the rectangular frame (<NUM>), and
wherein a communication hole (23a) is formed on each of lower sections of both fixing plates (<NUM>) so that either one of the communication holes (23a) communicates with the heat exchange fluid discharge port (<NUM>).