JP2018096638A - Condenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a condenser which can improve cooling performance by securing a sufficient temperature difference in any of heat exchange cores which are aligned in two rows in a fore-and-aft direction in a flow direction of cooling air.SOLUTION: Related to a condenser 10 for continuously air-cooling an operation medium 4 by aligning heat exchange cores 2, 3 in two rows in a fore-and-aft direction in a flow direction of cooling air 1, a common upper header tank 11 and individual lower header tanks 8, 9 are arranged at the heat exchange cores 2, 3, respectively, the vapor of the operation medium 4 introduced into the rear-row lower header tank 9 is cooled by the cooling air 1, and brought into an air-liquid mixed state while the vapor ascends along the rear-row heat exchange core 3 up to the upper header tank 11, and while the vapor is folded from the upper header tank 11 to the front-row heat exchange core 2, and descends, the vapor is further air-cooled by the cooling air 1, and collected from the front-row lower header tank 8 as the condensed water of the operation medium 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a condenser that can be used in a Rankine cycle power generation system or the like.

  In recent years, hybrid vehicles with high fuel consumption performance using both an engine and a motor generator have become widespread, and a high penetration rate has already been achieved for passenger cars, while the penetration rate for large trucks and the like is starting to increase gradually. However, especially when hybridizing large trucks, a Rankine cycle power generation system has been adopted for the purpose of further improving fuel efficiency, and this has been researched to recover waste heat from exhaust gas and convert it to electrical energy. Yes.

  In this type of Rankine cycle power generation system, the working medium is vaporized using the waste heat of the exhaust gas, and the turbine is driven by the vaporized working medium to generate electric power. Since it is necessary to cool and condense with equal pressure, it is considered that a condenser is provided in the rear overhang of a large truck, and that the working medium is cooled by air using the condenser as cooling air to condense.

  At this time, in order to perform efficient heat exchange by arranging the condenser compactly in a limited range of the rear overhang, as shown in FIGS. 5 and 6, the heat exchange core 2 is arranged in the flow direction of the cooling air 1. , 3 are arranged in two front and rear rows, and the adoption of a condenser 5 in which the working medium 4 is continuously air-cooled is being studied.

  Here, each of the heat exchange cores 2 and 3 is constituted by a number of heat exchange tubes extending vertically, and forms a panel-like ventilation structure that allows the cooling air 1 to pass through the gaps between the heat exchange tubes. The gaps between the heat exchange tubes are equipped with fins or the like for increasing the heat exchange efficiency as necessary.

  As prior art document information related to the present invention, there is the following Patent Document 1 and the like.

JP 2007-155183 A

  However, in the conventional proposals shown in FIGS. 5 and 6, the steam of the working medium 4 is introduced into the upper header tanks 6 and 7 of the heat exchange cores 2 and 3 arranged in the flow direction of the cooling air 1, respectively. While the heat exchange cores 2 and 3 are lowered, heat is exchanged with the cooling air 1 to promote condensation, and the condensed liquid is collected in the respective lower header tanks 8 and 9, so that the flow of the cooling air 1 Even if the heat exchange core 2 arranged in the front row (upstream side) of the direction exchanges heat between the cooling air 1 and the working medium 4 with a sufficient temperature difference, the heat exchange core 3 in the rear row (downstream side) After the cooling of the working medium 4 by the heat exchange core 2, the cooling air 1 that has been warmed cools the working medium 4, and the temperature difference between the cooling air 1 and the working medium 4 is reduced, resulting in good cooling performance. There was a problem that it could not be obtained.

  The present invention has been made in view of the above circumstances, and it is possible to secure a sufficient temperature difference and improve the cooling performance in any of the heat exchange cores arranged in two rows before and after in the flow direction of the cooling air. The object is to provide a condenser.

  The present invention is a condenser in which heat exchange cores are arranged in two rows in the front and rear in the flow direction of cooling air to continuously air-cool the working medium, and each of the heat exchange cores has a common upper header tank and separate lower portions. And the working medium vapor introduced into the lower header tank in the rear row is air-cooled by cooling air while rising up the heat exchange core in the rear row to the upper header tank, and becomes a gas-liquid mixed state. While being folded back to the heat exchange core in the front row and descending, it is further cooled by cooling air and is collected from the lower header tank in the front row as a condensate of the working medium.

  Thus, in this case, the steam of the working medium having a high temperature introduced into the lower header tank of the rear row and rising the heat exchange core in the rear row has already finished heat exchange in the heat exchange core in the front row and raised the temperature. The air is cooled and air-cooled by heat exchange with the cooled cooling air, reaches a gas-liquid mixed state accompanied by mist-like condensate in the flow, reaches the upper header tank, and is folded back from the upper header tank to the heat exchange core in the front row. Then, the heat is exchanged with cooling air having a low temperature that is not yet used for heat exchange and further air-cooled, and all the vapor of the working medium becomes a condensate and flows down to the lower header tank in the front row.

  That is, mutual heat exchange is performed such that the working medium goes back from the rear row heat exchange core to the front row heat exchange core with respect to the flow direction of the cooling air. As a result, a sufficient temperature difference is ensured in any of the heat exchange cores arranged in two rows in the front-rear direction in the flow direction of the cooling air, thereby improving the cooling performance.

  Moreover, in the heat exchange cores in the front row where the condensation of the working medium progresses in earnest and becomes droplets from the mist state, the flow of the working medium forms a downward flow downward. The working medium formed into droplets by the heat exchanging core flows smoothly into the lower header tank in the front row without being retained in the middle due to not only the pressure but also the action of gravity.

  Further, in the present invention, a required inclination angle is formed with respect to the vertical direction so that the cooling air inlet side of the front row heat exchange core faces downward and the cooling air outlet side of the rear row heat exchange core faces upward. It is preferable that they are arranged obliquely.

  In this way, it is possible to arrange each heat exchange core in a compact arrangement with respect to a narrow arrangement space where there is a height restriction, and in addition, a stagnation part of the flow of the upper header tank where the working medium is folded back Even if condensate is generated in the upper header tank, the condensate is smoothly drained down to the heat exchange core in the front row by the action of gravity, so that it is prevented that the condensate stays in the upper header tank or flows back to the heat exchange core in the rear row. The

  Furthermore, in the present invention, it is preferable that the rear overhang of the large truck is equipped so that the vapor of the working medium of the Rankine cycle power generation system employed in the large truck can be condensed. It becomes possible to arrange the condenser compactly in a limited range of overhang and to perform efficient heat exchange.

  According to the condenser of the present invention described above, various excellent effects as described below can be obtained.

  (I) According to the invention described in claim 1 of the present invention, the heat exchange type between the cooling air and the working medium is counterflowed, and in any of the heat exchange cores arranged in two rows in the front and rear in the cooling air flow direction. In addition, a sufficient temperature difference can be ensured, and the cooling performance can be greatly improved as compared with the prior art. Moreover, the dropletized working medium can flow smoothly without being retained in the middle due to the action of gravity. .

  (II) According to the invention described in claim 2 of the present invention, each heat exchange core can be inclined and arranged compactly with respect to a narrow arrangement space having a height restriction, and the upper header can be arranged. It is also possible to prevent the condensate from staying in the tank or flowing back to the heat exchange core in the rear row.

  (III) According to the invention described in claim 3 of the present invention, the condenser can be arranged compactly in a limited range of the rear overhang so that efficient heat exchange can be performed. Effective application of the Rankine cycle power generation system can be realized.

It is a perspective view which shows an example of the form which implements this invention. It is a side view of the condenser of FIG. It is a graph explaining the form of heat exchange with a cooling wind and a working medium. It is the schematic which shows the example applied to the rear overhang of a large truck. It is a perspective view which shows a prior art example. FIG. 6 is a side view of the condenser of FIG. 5.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 3 show an example of an embodiment for carrying out the present invention. In this embodiment, heat exchange is performed in the flow direction of the cooling air 1 in the same manner as the conventional example described above with reference to FIGS. The condenser 10 is configured such that the working medium 4 is continuously air-cooled by arranging the cores 2 and 3 in two rows in the front and rear, and the heat exchange cores 2 and 3 are panel-shaped by a number of heat exchange tubes extending vertically. The cooling air 1 can pass through the gaps between the heat exchange tubes, but the lower ends of the heat exchange tubes in the heat exchange cores 2 and 3 are connected to the individual lower header tanks 8 and 9, respectively. Whereas the upper ends of the heat exchange tubes in the respective heat exchange cores 2 and 3 are connected to a common upper header tank 11, the lower header tank 9 in the rear row is used as the entry side for the working medium 4. The lower header tank 8 in the front row As the outlet side are as above may wrap upper header tank 11 the working medium 4 from the heat exchange core 3 of rear row through the heat exchange core 2 of the front row.

  Here, in the condenser 10 in this embodiment, as schematically shown in FIG. 2, the vapor (gas phase) of the working medium 4 introduced into the lower header tank 9 in the rear row moves up the heat exchange core 3 in the rear row. The air is cooled by the cooling air 1 while rising to the header tank 11 to be in a gas-liquid mixed state, and is further cooled by the cooling air 1 while being folded back from the upper header tank 11 to the heat exchange core 2 in the front row. 4 condensate (liquid phase) is designed to be collected in the lower header tank 8 in the front row.

  Thus, in the case of such a condenser 10, the steam of the high-temperature working medium 4 introduced into the lower header tank 9 in the rear row and rising the rear row heat exchange core 3 is already in the front row heat exchange core 2. The heat is exchanged with the cooling air 1 that has been heated up after the heat exchange and is air-cooled, and is in a gas-liquid mixed state accompanied by a mist-like condensate in the flow to reach the upper header tank 11, The header tank 11 is folded back to the heat exchange core 2 in the front row, descends, is heat-exchanged with the cooling air 1 having a low temperature not yet used for heat exchange, is further air-cooled, and all the vapor of the working medium 4 is condensed with the condensate. Thus, it flows down to the lower header tank 8 in the front row.

  That is, mutual heat exchange is performed such that the working medium 4 goes back from the rear heat exchange core 3 to the front heat exchange core 2 with respect to the flow direction of the cooling air 1, and is schematically shown in FIG. As described above, the heat exchange between the cooling air 1 and the working medium 4 is counterflowed, and the heat exchange cores 2 and 3 arranged in two rows in the front and rear directions in the flow direction of the cooling air 1 have a sufficient temperature. The difference is secured and the cooling performance is improved.

  In addition, in the heat exchange core 2 in the front row where the condensation of the working medium 4 progresses in earnest and drops from the mist state, the flow of the working medium 4 forms a downward flow downward. Therefore, the working medium 4 formed into droplets by the heat exchange core 2 in the front row smoothly flows down to the lower header tank 8 in the front row without being retained in the middle due to not only the pressure but also the action of gravity. Become.

  Therefore, according to the above embodiment, the heat exchange between the cooling air 1 and the working medium 4 is counterflowed, and the heat exchange cores 2 and 3 arranged in two rows in the front and rear directions in the flow direction of the cooling air 1 are sufficient. Thus, the cooling performance can be greatly improved as compared with the prior art by ensuring a sufficient temperature difference, and the droplets of the working medium 4 can be smoothly flowed down without being retained in the middle due to the action of gravity.

  In addition, as shown in FIG. 4, when the condenser 10 of the present embodiment as described above is used to condense the vapor of the working medium 4 of the Rankine cycle power generation system employed in the large truck 12, the The limited range of the rear overhang 13 while taking into account height restrictions such as the launch angle (angle between the tangent line connecting the bottom of the vehicle in the rear overhang 13 and the rear ground contact surface of the rear wheel tire and the ground) and the minimum ground clearance Therefore, it is necessary to arrange the condenser 10 in a compact manner, and the heat exchange cores 2 and 3 must be arranged obliquely at a predetermined inclination angle with respect to the vertical direction.

  At this time, a required inclination angle with respect to the vertical direction is such that the entrance side of the cooling air 1 (running wind) in the front heat exchange core 2 faces downward and the exit surface of the cooling air 1 in the rear heat exchange core 3 faces upward. If the heat exchanger cores 2 and 3 are inclined, the heat exchange cores 2 and 3 can be inclined and arranged in a compact manner, and condensate is generated in the stagnation portion of the flow of the upper header tank 11 where the working medium 4 is folded back. However, it is possible to smoothly flow down to the heat exchange core 2 in the front row by the action of gravity, and to prevent the condensate from staying in the upper header tank 11 or flowing back to the heat exchange core 3 in the rear row. be able to.

  In addition, the condenser of this invention is not limited only to the above-mentioned form example, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 Cooling air 2 Front row heat exchange core 3 Rear row heat exchange core 4 Working medium 8 Front row lower header tank 9 Rear row lower header tank 10 Condenser 11 Upper header tank 12 Large truck 13 Rear overhang

Claims (3)

  A condenser in which heat exchange cores are arranged in two rows before and after in the flow direction of the cooling air to continuously air-cool the working medium, and each heat exchange core includes a common upper header tank and individual lower header tanks. The steam of the working medium introduced into the lower header tank in the rear row is cooled by air while being raised up the heat exchange core in the rear row to the upper header tank, and becomes a gas-liquid mixed state, and heat exchange in the front row from the upper header tank A condenser configured to be further cooled by cooling air while returning to a core and descending and then recovered as a condensate of a working medium from a lower header tank in a front row.   The cooling air inlet side of the front row heat exchange core is faced downward and the cooling air outlet side of the rear row heat exchange core is faced upward with a required inclination angle with respect to the vertical direction. The condenser according to claim 1.   The condenser according to claim 1 or 2, wherein the condenser is installed in a rear overhang of the large truck so as to condense the vapor of the working medium of the Rankine cycle power generation system employed in the large truck.