JP2009250566A - Multitubular heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat transferring efficiency by increasing a refrigerant flow rate of heat transfer tubes in a multitubular heat exchanger. <P>SOLUTION: In this multitubular heat exchanger in which a number of heat transfer tubes 2, 2, ... are horizontally arranged in a barrel body 1 in which a cooled fluid W is circulated, and both ends of the barrel body 1 are respectively provided with a refrigerant inlet/outlet section 3 as a refrigerant inlet 4 and a refrigerant outlet 5 to the heat transfer tubes 2, and a refrigerant flow-back section 6 for allowing the refrigerant flowing into the heat transfer tubes 2 to flow back therein, the refrigerant flow-back section 6 includes a liquid storing section 7 for storing a liquid refrigerant X, and a flow-back pathway 8 for allowing the liquid refrigerant X of the liquid storing section 7 to flow back to the refrigerant inlet 4, and the liquid refrigerant X stored in the liquid storing section 7 of the refrigerant flow-back section 6 flows back to the refrigerant inlet 4 through the flow-back pathway 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shell and tube type multi-tube heat exchanger used as a dry water cooler.

  For example, as shown in FIG. 3, a shell-and-tube type multi-tube heat exchanger has a large number of heat transfer tubes 2, 2... Horizontally disposed in a body 1 through which a fluid to be cooled flows. 1 at both ends, a refrigerant inlet / outlet portion 3 serving as a refrigerant inlet 4 and a refrigerant outlet 5 into the heat transfer tubes 2,..., And a refrigerant reflux portion 6 through which the refrigerant flowing through the heat transfer tubes 2, 2. Are arranged.

  This type of multi-tube heat exchanger has been well known as disclosed in Patent Document 1.

JP 2000-227299 A.

  When the multi-tube heat exchanger having the above configuration is used as a dry water cooler, it is incorporated into a refrigeration cycle comprising a compressor 11, a condenser 12, an expansion mechanism 13 and a multi-tube heat exchanger 14 as shown in FIG. Used in. In FIG. 3, reference numeral 15 is a water inlet, and 16 is a water outlet.

  In the case of the refrigeration cycle, the gas refrigerant compressed by the compressor 11 is condensed and liquefied in the condenser 12 to become liquid refrigerant, and the liquid refrigerant is decompressed by the expansion mechanism 13 and then functions as an evaporator. In the process of being led to the heat exchanger 14 and evaporating and evaporating in the multi-tube heat exchanger 14, the water W supplied from the water inlet 15 and led out from the water outlet 16 is cooled. If the amount is not sufficient, the liquid refrigerant X flowing in the heat transfer tube 2 is biased downward as shown in FIG. 4, and the wetted surface of the inner surface of the heat transfer tube 2 is reduced. Then, the malfunction that the heat transfer efficiency to the to-be-cooled fluid (for example, water W) which flows out of the heat exchanger tube 2 from the liquid refrigerant X which flows in the heat exchanger tube 2 will generate | occur | produce will generate | occur | produce.

  This invention is made | formed in view of said point, and aims at improving a heat transfer efficiency by increasing the refrigerant | coolant flow rate of the heat exchanger tube in a multi-tube heat exchanger.

  In the present invention, as a first means for solving the above problems, a large number of heat transfer tubes 2, 2... Are horizontally disposed in the body 1 through which the fluid W to be cooled flows, The refrigerant inlet / outlet part 3 serving as the refrigerant inlet 4 and the refrigerant outlet 5 into the heat transfer tubes 2, 2... And the refrigerant reflux unit 6 through which the refrigerant flowing through the heat transfer tubes 2, 2. In the multi-tube heat exchanger formed as described above, the refrigerant recirculation unit 6 is provided with a liquid reservoir 7 in which the liquid refrigerant X is stored, and the liquid refrigerant X in the liquid reservoir 7 is recirculated to the refrigerant inlet 4. A reflux passage 8 is formed.

  With the configuration described above, the liquid refrigerant X stored in the liquid reservoir 7 of the refrigerant recirculation unit 6 in the multi-tube heat exchanger enters the refrigerant inlet 4 in the multi-tube heat exchanger via the recirculation passage 8. As a result, the refrigerant circulation amount supplied to the heat transfer tubes 2, 2... In the multi-tube heat exchanger increases by the amount of the liquid refrigerant X that is recirculated from the liquid reservoir 8. Therefore, the wetting surface on the inner surface of each heat transfer tube 2 increases, and the heat transfer efficiency from the liquid refrigerant X flowing in the heat transfer tube 2 to the cooled fluid water W flowing outside the heat transfer tube 2 is improved.

  In the present invention, as a second means for solving the above problem, in the multi-tube heat exchanger provided with the first means, the liquid refrigerant X in the liquid reservoir portion 7 is supplied to the refrigerant inlet 4. Refrigerant feeding means 9 for recirculation can be provided. In such a case, the liquid refrigerant X stored in the liquid reservoir 7 is smoothly and reliably supplied to the refrigerant inlet 4 by the feeding action of the refrigerant feeding means 9. Will be refluxed.

  In the present invention, as a third means for solving the above problems, in the multitubular heat exchanger provided with the second means, the refrigerant feeding means 9 communicates with the refrigerant inlet 4. An ejector interposed in the connection portion of the reflux passage 8 in the inlet pipe 10 can also be adopted. In such a configuration, the liquid refrigerant X stored in the liquid storage portion 7 due to the negative pressure generated in the ejector 9 is obtained. The refrigerant is supplied to the inlet pipe 10 through the reflux passage 8, and the circulation amount of the refrigerant to the heat transfer pipes 2, 2,... In the multi-tube heat exchanger can be increased without using any power. .

  According to the first means of the present invention, a plurality of heat transfer tubes 2, 2... Are horizontally disposed in the body 1 through which the fluid W to be cooled flows, and the heat transfer tubes 2, 2 are disposed at both ends of the body 1. 2. A multi-tube type in which a refrigerant inlet / outlet part 3 serving as a refrigerant inlet 4 and a refrigerant outlet 5 to the inside and a refrigerant recirculation part 6 through which the refrigerant flowing in the heat transfer pipes 2, 2,. In the heat exchanger, a liquid reservoir portion 7 in which the liquid refrigerant X is stored is provided in the refrigerant recirculation portion 6, and a reflux passage 8 for recirculating the liquid refrigerant X in the liquid reservoir portion 7 to the refrigerant inlet 4 is formed. Since the liquid refrigerant X stored in the liquid reservoir 7 of the refrigerant recirculation part 6 is recirculated to the refrigerant inlet 4 through the recirculation passage 8, the refrigerant circulation supplied to the heat transfer tubes 2, 2,. The amount increases by the amount of the liquid refrigerant X recirculated from the liquid reservoir 8, and the wetted surface on the inner surface of each heat transfer tube 2. It becomes possible to increase an effect of improving the heat transfer efficiency from the liquid refrigerant X flowing in the heat exchanger tube 2 to the fluid to be cooled W flowing through the heat transfer tubes 2 outside.

  As in the second means of the present invention, in the multi-tube heat exchanger provided with the first means, a refrigerant feeding means 9 for recirculating the liquid refrigerant X in the liquid reservoir 7 to the refrigerant inlet 4 is provided. In this case, the liquid refrigerant X stored in the liquid reservoir 7 is smoothly and reliably recirculated to the refrigerant inlet 4 by the feeding action of the refrigerant feeding means 9.

  As in the third means of the present invention, in the multi-tubular heat exchanger provided with the second means, the reflux passage 8 in the inlet pipe 10 communicating with the refrigerant inlet 4 as the refrigerant feeding means 9. It is also possible to employ an ejector interposed in the connecting portion of the liquid crystal. In such a configuration, the liquid refrigerant X stored in the liquid reservoir portion 7 by the negative pressure generated in the ejector 9 is introduced into the inlet pipe via the reflux passage 8. Thus, the refrigerant circulation amount to the heat transfer tubes 2, 2... In the multi-tube heat exchanger can be increased without using any power.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  As shown in FIG. 1, this multitubular heat exchanger has a number of heat transfer tubes 2, 2... Horizontally disposed in a body 1 through which water W as a fluid to be cooled flows. At both ends, a front lid 3 which is a refrigerant inlet / outlet part serving as a refrigerant inlet 4 and a refrigerant outlet 5 into the heat transfer tubes 2, 2... And a refrigerant reflux through which the refrigerant flowing through the heat transfer tubes 2, 2. A rear lid 6 as a part is arranged.

  When the multi-tube heat exchanger having the above configuration is used as a dry water cooler, it is incorporated into a refrigeration cycle comprising a compressor 11, a condenser 12, an expansion mechanism 13 and a multi-tube heat exchanger 14 as shown in FIG. Used in. In FIG. 1, reference numeral 15 is a water inlet, and 16 is a water outlet.

  In the present embodiment, the rear lid 6 which is a refrigerant recirculation part is provided with a liquid reservoir part 7 for storing the liquid refrigerant X, and the liquid refrigerant X of the liquid reservoir part 7 is supplied to the refrigerant inlet 4. A reflux passage 8 for reflux is formed. An ejector 9 functioning as a refrigerant feeding means for refluxing the liquid refrigerant X in the liquid reservoir 7 to the refrigerant inlet 4 is connected to the reflux passage 8 in the inlet pipe 10 communicating with the refrigerant inlet 4. It is installed. The ejector 9 includes an accelerating portion 9a for accelerating the flow rate of the liquid refrigerant X flowing through the inlet pipe 10, and the reflux passage 8 is connected to the downstream side of the accelerating portion 9a. Accordingly, in this ejector 9, a negative pressure is generated immediately downstream of the acceleration portion 9 a, and the liquid refrigerant X in the liquid reservoir portion 7 is returned to the refrigerant inlet 4 through the reflux passage 8 due to the negative pressure. It will be.

  In the case of the refrigeration cycle, the gas refrigerant compressed by the compressor 11 is condensed and liquefied in the condenser 12 to become liquid refrigerant, and the liquid refrigerant is decompressed by the expansion mechanism 13 and then functions as an evaporator. In the process of being led to the heat exchanger 14 and evaporating and evaporating in the multitubular heat exchanger 14, the water W supplied from the water inlet 15 and led out from the water outlet 16 is cooled.

  By the way, in the present embodiment, the liquid refrigerant X stored in the liquid reservoir portion 7 of the rear lid 6 is recirculated to the refrigerant inlet 4 via the recirculation passage 8 due to the negative pressure generated on the downstream side of the ejector 9. Therefore, the refrigerant circulation amount supplied to the heat transfer tubes 2, 2... Increases by the amount of the liquid refrigerant X recirculated from the liquid reservoir 8. That is, the sum of the refrigerant circulation amount G in the refrigeration cycle and the refrigerant recirculation amount g that recirculates through the recirculation passage 8 becomes the refrigerant supply amount in the multi-tube heat exchanger, and as shown in FIG. The wetted surface on the inner surface will increase. As a result, the heat transfer efficiency from the liquid refrigerant X flowing inside the heat transfer tube 2 to the water W flowing outside the heat transfer tube 2 is improved.

  In addition, an ejector 9 interposed in the connection portion of the reflux passage 8 in the inlet pipe 10 communicating with the refrigerant inlet 4 is employed as a refrigerant feeding means for refluxing the liquid refrigerant X in the liquid reservoir 7 to the refrigerant inlet 4. As a result, the liquid refrigerant X stored in the liquid reservoir 7 due to the negative pressure generated in the ejector 9 is supplied to the inlet pipe 10 via the recirculation passage 8, and the multi-tube heat exchange is performed without using any power. It is possible to increase the amount of refrigerant circulation to the heat transfer tubes 2, 2.

  In the above embodiment, an ejector is employed as the refrigerant feeding means. However, a pump may be provided in the middle of the recirculation passage to serve as the refrigerant feeding means.

  In the above embodiment, the refrigerant reciprocates once in the body, but the present invention can also be applied to the case where the refrigerant reciprocates twice in the body. Even in that case, the liquid reservoir is provided in the refrigerant recirculation part.

  The invention of the present application is not limited to the above-described embodiment, and it is needless to say that the design can be appropriately changed without departing from the gist of the invention.

A refrigeration cycle using a multi-tube heat exchanger according to an embodiment of the present invention is shown. It is an expanded sectional view of the heat exchanger tube in the multitubular heat exchanger concerning an embodiment of the invention of this application. A refrigeration cycle using a conventional multi-tube heat exchanger is shown. It is an expanded sectional view of the heat exchanger tube in the conventional multitubular heat exchanger.

Explanation of symbols

1 is a fuselage 2 is a heat transfer tube 3 is a refrigerant inlet / outlet part (front cover)
4 is a refrigerant inlet 5 is a refrigerant outlet 6 is a refrigerant recirculation part (rear cover)
7 is a liquid reservoir 8 is a reflux passage 9 is a refrigerant feeding means (ejector)
10 is the inlet pipe W is the fluid to be cooled (water)
X is liquid refrigerant

Claims (3)

  A large number of heat transfer tubes (2), (2),... Are horizontally disposed in the body (1) through which the fluid to be cooled (W) flows, and the heat transfer tubes (2) are disposed at both ends of the body (1). ), (2) .. Refrigerant inlet / outlet part (3) serving as a refrigerant inlet (4) and refrigerant outlet (5), and the refrigerant flowing through the heat transfer tubes (2), (2). A multi-tube heat exchanger comprising a refrigerant recirculation part (6), wherein the refrigerant recirculation part (6) is provided with a liquid reservoir part (7) in which liquid refrigerant (X) is stored. In addition, a multi-pipe heat exchanger is characterized in that a reflux passage (8) for returning the liquid refrigerant (X) in the liquid reservoir (7) to the refrigerant inlet (4) is formed.   The refrigerant circulation means (9) for recirculating the liquid refrigerant (X) in the liquid reservoir (7) to the refrigerant inlet (4) is attached to the recirculation passage (8). The multitubular heat exchanger described.   The multi-tube heat exchanger according to claim 2, wherein an ejector for accelerating the refrigerant supplied to the refrigerant inlet (4) is adopted as the refrigerant feeding means (9).

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