GAS COOLER DESIGN METHOD

Abstract

A method of designing a gas cooler includes acquiring information on a condition of a gas flowing through a flow path in a shell main body and a condition of a cooling medium flowing through at least one pipe; setting a provisional arrangement condition of the at least one pipe when viewed from a second direction intersecting a first direction in which the gas flows in the flow path; and acquiring a relationship between an adhesion rate of condensed water of moisture contained in the gas to an outside surface of the at least one pipe and a decrease rate of an efficiency of heat exchange between the gas and the cooling medium on a basis of the acquired information on the condition of the gas, the acquired information on the condition of the cooling medium, and the set provisional arrangement condition.

Claims

1. A method of designing a gas cooler including a shell main body that is hollow and into which a gas containing moisture is fed from outside, a flow path-forming section that forms a flow path of the gas in the shell main body, and at least one pipe that is disposed passing through the flow path in the shell main body and through which a cooling medium flows, the method comprising: acquiring information on a condition of the gas flowing through the flow path in the shell main body and a condition of the cooling medium flowing through the at least one pipe; setting a provisional arrangement condition of the at least one pipe when viewed from a second direction intersecting a first direction in which the gas flows in the flow path; acquiring a relationship between an adhesion rate of condensed water of moisture contained in the gas to an outside surface of the at least one pipe and a decrease rate of an efficiency of heat exchange between the gas and the cooling medium on a basis of the acquired information on the condition of the gas, the acquired information on the condition of the cooling medium, and the set provisional arrangement condition; determining whether or not the relationship between the adhesion rate of the condensed water and the decrease rate satisfies a predetermined reference condition; and determining an arrangement of the at least one pipe on a basis of the provisional arrangement condition when the reference condition is satisfied as a result of the determining.

2. The method of designing a gas cooler, according to claim 1, wherein the relationship between the adhesion rate of the condensed water and the decrease rate is acquired as a function of a flow velocity of the gas.

3. The method of designing a gas cooler, according to claim 1, wherein the shell main body is formed in a tubular shape extending around an axis extending in the second direction, and in the setting of the provisional arrangement condition, an arrangement and the number of the at least one pipe when viewed from the second direction are set as the provisional arrangement condition.

4. The method of designing a gas cooler, according to claim 3, wherein the number of the at least one pipe arranged in a third direction intersecting the first direction and the second direction is smaller than the number of the at least one pipe arranged in the first direction.

5. The method of designing a gas cooler, according to claim 3, wherein in the setting of the provisional arrangement condition, a size of a flow path cross-sectional area of the flow path when viewed from the first direction is set as the provisional arrangement condition.

6. The method of designing a gas cooler, according to claim 3, wherein in the setting of the provisional arrangement condition, a size of a flow path cross-sectional area of the flow path when viewed from the second direction is set as the provisional arrangement condition.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0010] FIG. 1 illustrates a schematic configuration of a compressor system including a gas cooler designed by a gas cooler design method according to an embodiment of the present disclosure.

[0011] FIG. 2 is a perspective view of the gas cooler.

[0012] FIG. 3 is a cross-sectional view of the gas cooler as viewed from the axial direction at a portion of an inlet nozzle.

[0013] FIG. 4 is a flowchart illustrating a procedure of the gas cooler design method according to the embodiment of the present disclosure.

[0014] FIG. 5 indicates an example of a function of a pipe group passage flow velocity, indicating the relationship between the flow velocity of a gas and the decrease amount of the efficiency of heat exchange of the gas.

DESCRIPTION OF EMBODIMENTS

[0015] Hereinafter, embodiments for implementing a gas cooler design method according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited only to these embodiments.

(Configuration of Compressor System)

[0016] As illustrated in FIG. 1, a gas cooler 1 designed by the gas cooler design method according to the present disclosure is disposed as part of a compressor system 8. The compressor system 8 includes a plurality of compressors 9 connected in series and the gas cooler 1. The plurality of compressors 9 are connected in series. In the present embodiment, two compressors 9 are disposed, for example. The number of compressors 9 included in the compressor system 8 may be only one or may be three or more.

[0017] A gas G to be compressed in the compressor system 8 is a gas containing moisture. The gas G is compressed by a preceding-stage compressor 9A and then fed into a following-stage compressor 9B. The gas G compressed by the preceding-stage compressor 9A is further compressed by the following-stage compressor 9B. The gas cooler 1 is disposed between the preceding-stage compressor 9A and the following-stage compressor 9B. The gas cooler 1 is connected to the outlet side of the preceding-stage compressor 9A via a preceding-stage connection pipe 10A. The gas cooler 1 is connected to the inlet side of the following-stage compressor 9B via a following-stage connection pipe 10B.

(Configuration of Gas Cooler)

[0018] The gas cooler 1 cools the gas G compressed by the preceding-stage compressor 9A. The gas cooler 1 reduces the power required to drive the following-stage compressor 9B by intermediately cooling the gas G in the compression process. In the present embodiment, the gas G cooled by the gas cooler 1 is, for example, a carbonic acid (CO.sub.2) gas containing moisture. The gas G to be cooled by the gas cooler 1 is not limited to a carbon dioxide gas, and may be other gases such as air or nitrogen as long as they contain moisture. As illustrated in FIGS. 2 and 3, the gas cooler 1 of the present embodiment mainly includes a shell 2, a cooler 3, and a partition member 5 (see FIG. 2).

(Configuration of Shell)

[0019] The shell 2 has a hollow structure. The shell 2 includes a shell main body 21, an inlet nozzle 24, and an outlet nozzle 25.

[0020] The shell main body 21 is formed to be hollow. The gas G containing moisture is fed into the shell main body 21 from the outside. The shell main body 21 is formed in a bottomed tubular shape extending around an axis O that extends in an axial direction Da. The shell main body 21 is disposed such that the axis O coincides with the horizontal direction. The inside diameter of the shell 2 is preferably made as large as possible in order to suppress an uneven flow of the gas G inside the shell 2.

[0021] The inlet nozzle 24 and the outlet nozzle 25 are integrally connected to the shell main body 21. The inlet nozzle 24 and the outlet nozzle 25 are disposed with a space from each other in the axial direction (second direction) Da in which the axis O extends. The inlet nozzle 24 is disposed on a first side Dal in the axial direction Da with respect to a center 21c of the shell main body 21 in the axial direction Da. The outlet nozzle 25 is disposed on a second side Da2 in the axial direction Da with respect to the center 21c of the shell main body 21. The inlet nozzle 24 and the outlet nozzle 25 are disposed at the upper portion, in a vertical direction (third direction) Dv or a direction inclined from the vertical direction, of the shell main body 21 disposed in a horizontal state. The inlet nozzle 24 and the outlet nozzle 25 are formed in a tubular shape extending upward, in the vertical direction Dv or a direction inclined from the vertical direction, from the upper portion of the shell main body 21. As illustrated in FIG. 3, the lower ends of the inlet nozzle 24 and the outlet nozzle 25 are open at the inside surface of the shell main body 21 so as to communicate with the interior of the shell main body 21.

(Configuration of Cooler)

[0022] The cooler 3 is disposed inside the shell main body 21. The cooler 3 is capable of cooling the gas G by causing the gas G flowing from the inlet nozzle 24 toward the outlet nozzle 25 to flow through the inside thereof. The cooler 3 includes a flow path-forming section 30 and a pipe group 31. The cooler 3 has a rectangular parallelepiped shape extending in the axial direction Da as a whole.

[0023] The flow path-forming section 30 forms a flow path 30r, through which the gas G passes around the pipe group 31, in the cooler 3 in the shell main body 21. That is, the flow path-forming section 30 forms the flow path 30r in which the pipe group 31 is disposed and through which the gas G can flow. The flow path-forming section 30 includes a first plate portion 32 and a second plate portion 33.

[0024] As illustrated in FIGS. 2 and 3, the first plate portion 32 is disposed above the pipe group 31 to be described later in the vertical direction Dv. The first plate portion 32 is disposed at a position facing the inlet nozzle 24 and the outlet nozzle 25 with respect to the pipe group 31. The first plate portion 32 has a flat plate shape and extends along a plane (horizontal plane) orthogonal to the vertical direction Dv. The first plate portion 32 is formed in a rectangular shape when viewed from the vertical direction Dv orthogonal to the axial direction Da. The first plate portion 32 is disposed so as to cover the entire pipe group 31 from above in the vertical direction Dv.

[0025] An end portion 32a of the first plate portion 32 on a first side Dw1 in a width direction (first direction) Dw orthogonal to the axial direction Da is disposed with a space from the shell main body 21. An end portion 32b of the first plate portion 32 on a second side Dw2 in the width direction Dw is disposed with a space from the shell main body 21.

[0026] The second plate portion 33 is disposed on the opposite side of the first plate portion 32 with the pipe group 31 interposed therebetween. That is, the second plate portion 33 is disposed below the pipe group 31 in the vertical direction Dv. The second plate portion 33 has a flat plate shape and extends along a plane (horizontal plane) orthogonal to the vertical direction Dv. The second plate portion 33 is formed in a rectangular shape when seen from the vertical direction Dv. The second plate portion 33 is disposed so as to cover the entire pipe group 31 from below in the vertical direction Dv.

[0027] An end portion 33a of the second plate portion 33 on the first side Dw1 in the width direction Dw is in contact with the inside surface of the shell main body 21. An end portion 33b of the second plate portion 33 on the second side Dw2 in the width direction Dw is disposed with a space from the inside surface of the shell main body 21.

[0028] The flow path-forming section 30 forms the flow path 30r, through which the gas G passes the pipe group 31, in a region surrounded by the first plate portion 32, the second plate portion 33, a first shell end portion 211 of the shell main body 21 on the first side Dal in the axial direction Da, and a second shell end portion 212 of the shell main body 21 on the second side Da2 in the axial direction Da. The flow path 30r is a rectangular parallelepiped region (space) elongated in the axial direction Da inside the shell main body 21. The flow path 30r communicates with the first side Dw1 and the second side Dw2 in the width direction Dw inside the shell main body 21. The flow path 30r is formed in a rectangular shape elongated in the width direction Dw when viewed from the axial direction Da (a portion surrounded by the long dashed double-dotted lines in FIG. 3).

[0029] The pipe group 31 is disposed so as to pass through the flow path 30r formed by the flow path-forming section 30. The pipe group 31 includes a plurality of pipes 35.

[0030] Each pipe 35 extends in the axial direction Da in the shell main body 21. The plurality of pipes 35 are disposed at intervals in the vertical direction Dv and the width direction Dw. The plurality of pipes 35 are arranged such that the pipes 35 adjacent to each other in the width direction Dw have the same installation height in the vertical direction Dv. That is, the plurality of pipes 35 are arranged such that, when viewed from the axial direction Da, the four closest pipes 35 are positioned at the vertices of a quadrangle.

[0031] The pipe 35 is folded back in a U-shape at a position close to the second shell end portion 212 on the second side Da2 in the axial direction Da in the shell main body 21. The pipe diameters of the pipes 35 are equal to or smaller than a diameter of 30 mm, for example. Water, for example, is supplied as a cooling medium into the pipes 35. In each pipe 35, water as the cooling medium flows from the first side Dal toward the second side Da2 in the axial direction Da. The flow direction of the water is changed at a portion where the pipe 35 is folded back in a U-shape, and the water flows from the second side Da2 toward the first side Dal in the axial direction Da.

[0032] In the following description, the pipe 35 on one side and the pipe 35 on the other side with respect to a portion where the pipe 35 is folded back in a U-shape at a position close to the second shell end portion 212 will each be described as one separate pipe 35. Further, the pipe 35 is not limited to being structured to be folded back in a U-shape. The pipe 35 may be a straight pipe penetrating the shell main body 21 in the axial direction Da. That is, the pipe 35 may be a straight pipe penetrating the shell main body 21 in the axial direction Da, or may be structured to be folded back at an intermediate header.

[0033] In the cooler 3, the gas G comes into contact with the pipes 35 by passing through the flow path 30r between the first plate portion 32 and the second plate portion 33 disposed on the upper and lower sides in the vertical direction Dv. Here, the gas G flows in the width direction Dw between the first plate portion 32 and the second plate portion 33. That is, the width direction Dw coincides with a flow direction (first direction) Df in which the gas G flows in the cooler 3. In the description of the present embodiment, in the width direction Dw, a side of the pipe group 31 on which the gas G flows into the cooler 3 is referred to as the first side Dw1, and a side of the pipe group 31 on which the gas G flows out of the cooler 3 is referred to as the second side Dw2. Therefore, the flow direction Df is a direction from the first side Dw1 toward the second side Dw2 in the width direction Dw. In the present embodiment, a second direction orthogonal to (intersecting) the flow direction Df is the axial direction Da. Furthermore, in the present embodiment, a third direction orthogonal to (intersecting) the flow direction Df (width direction Dw) and the axial direction Da is the vertical direction Dv.

(Configuration of Partition Member)

[0034] As illustrated in FIG. 2, the partition member 5 is fixed to the first plate portion 32. In the shell main body 21, the partition member 5 extends on the first plate portion 32 from the first shell end portion 211 close to the inlet nozzle 24 toward the second shell end portion 212 close to the outlet nozzle 25. The partition member 5 partitions a space portion 2S between the cooler 3 and the shell main body 21. Specifically, the partition member 5 partitions the space portion 2S into a first space 21S communicating with the inlet nozzle 24 and a second space 22S communicating with the outlet nozzle 25. The partition member 5 integrally includes a main partition plate 51, a first guide portion 52, and a second guide portion 53.

[0035] The main partition plate 51 is disposed between the inlet nozzle 24 and the outlet nozzle 25 in the axial direction Da. The main partition plate 51 extends upward in the vertical direction Dv from the first plate portion 32. The main partition plate 51 is formed in a flat plate shape. The main partition plate 51 extends from the first plate portion 32 to the shell main body 21 so as to spread in a direction intersecting the axis O. That is, the main partition plate 51 is disposed so as to partition the space between the first plate portion 32 and the shell main body 21 into the first side Dal and the second side Da2 in the axial direction Da.

[0036] The first guide portion 52 is disposed on the first side Da1 in the axial direction Da with respect to the main partition plate 51. The first guide portion 52 extends from an end portion 51a of the main partition plate 51 on the second side Dw2 in the width direction Dw toward the first side Dal in the axial direction Da. The first guide portion 52 extends to be inclined toward the second side Dw2 in the width direction Dw from the first plate portion 32 toward the upper side in the vertical direction Dv. A tip portion of the first guide portion 52 is in contact with the shell main body 21. The first guide portion 52 is formed in a flat plate shape having substantially the same plate thickness as that of the main partition plate 51.

[0037] The second guide portion 53 is disposed on the second side Da2 in the axial direction Da with respect to the main partition plate 51. The second guide portion 53 extends from an end portion 51b of the main partition plate 51 on the first side Dw1 in the width direction Dw toward the second side Da2 in the axial direction Da. The second guide portion 53 extends to be inclined toward the first side Dw1 in the width direction Dw from the first plate portion 32 toward the upper side in the vertical direction Dv. A tip portion of the second guide portion 53 is in contact with the shell main body 21. The second guide portion 53 is formed in a flat plate shape having substantially the same plate thickness as that of the main partition plate 51.

(Description of Flow of Fluid in Shell)

[0038] As illustrated in FIG. 3, with the partition member 5 provided, the gas G that has flowed into the shell main body 21 from the inlet nozzle 24 flows into the first space 21S. The gas G that has flowed into the first space 21S collides with the first plate portion 32 and spreads along the top surface of the first plate portion 32 on the first side Dal in the axial direction Da with respect to the main partition plate 51. At the same time, the gas G also spreads along the top surface of the first plate portion 32 on the second side Da2 in the axial direction Da. The gas G is guided to the first side Dw1 in the width direction Dw by the first guide portion 52, passes through the clearance between the first plate portion 32 and the shell main body 21, flows around an end portion 32a of the first plate portion 32, and flows to the first side Dw1 in the width direction Dw with respect to the cooler 3. Further, the gas G flows into the flow path 30r between the first plate portion 32 and the second plate portion 33, passes through the gap in the pipe group 31, and flows from the first side Dw1 to the second side Dw2 in the width direction Dw.

[0039] The gas G that has passed through the flow path 30r (pipe group 31) from the first side Dw1 to the second side Dw2 in the width direction Dw flows out to the second side Dw2 in the width direction Dw with respect to the cooler 3. The gas G that has flowed out flows upward along the inside surface of the shell main body 21, flows around the end portion 32b of the first plate portion 32, and flows into the clearance between the first plate portion 32 and the shell main body 21. Thereafter, the gas G is guided by the second guide portion 53 on the second side Da2 in the axial direction Da with respect to the main partition plate 51 and flows out of the shell main body 21 from the outlet nozzle 25.

(Procedure of Gas Cooler Design Method)

[0040] Next, a method S10 of designing the gas cooler 1 described above will be described. As illustrated in FIG. 4, the method S10 of designing the gas cooler 1 according to the embodiment of the present disclosure includes: a step S11 of setting required specifications; a step S12 of setting provisional arrangement conditions; a step S13 of setting the flow rate of the cooling medium; a step S14 of calculating a numerical value related to heat exchange between the gas G and the cooling medium; a step S15 of checking a cooling medium outlet temperature; a step S16 of checking a gas outlet temperature; a step S17 of checking a gas pressure loss; a step S18 of acquiring the relationship between the adhesion rate of condensed water (adhesion rate of condensed water per unit area) and the decrease rate of the efficiency of heat exchange; a step S19 of checking an amount of heat exchange heat in the gas cooler 1; a step S20 of determining the specifications of the gas cooler 1; and a step S21 of checking the shell diameter of the shell main body 21.

[0041] In step S11 of setting required specifications, the required specifications of the gas cooler 1 are set. Specifically, in step S11, conditions of the gas G flowing through the flow path 30r in the shell main body 21 and conditions of the cooling medium flowing through the pipes 35 are set as the required specifications of the gas cooler 1 on the basis of the basic specifications of the compressor system 8. That is, the conditions of the gas G and the conditions of the cooling medium flowing through the pipes 35 are set to required values of the conditions of the gas G and the conditions of the cooling medium required for the gas cooler 1 in the compressor system 8. Here, examples of the conditions of the gas G include a flow rate of the gas G fed into the shell main body 21 from the inlet nozzle 24, an inlet temperature and an inlet pressure of the gas G at the inlet nozzle 24, an outlet temperature and an outlet pressure of the gas G at the outlet nozzle 25, a pressure loss caused from the inlet to the outlet of the gas G, and an absolute humidity of the gas G (components of the gas G). Examples of the conditions of the cooling medium include an inlet temperature of the cooling medium at the inlet of the pipes 35 and an outlet temperature of the cooling medium at the outlet of the pipes 35.

[0042] In step S12 of setting provisional arrangement conditions, provisional arrangement conditions of the plurality of pipes 35 when viewed from the axial direction Da in the flow path 30r are set. In step S12, the arrangement and the number of the plurality of pipes 35 when viewed from the axial direction Da are set as the provisional arrangement conditions. Further, in step S12, the size of the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw is set as the provisional arrangement conditions. In addition, in step S12, the size of the flow path cross-sectional area of the flow path 30r when viewed from the axial direction Da is set as the provisional arrangement conditions.

[0043] To be specific, in step S12 of the present embodiment, first, a length dimension L1 (see FIG. 2), in the axial direction Da, of the plurality of pipes 35 constituting the pipe group 31 is temporarily set as one of the provisional arrangement conditions. Here, the length dimension L1 of the pipes 35 in the axial direction Da is the length of the pipes 35 between the first shell end portion 211 and the second shell end portion 212 of the shell main body 21, for example. Further, in step S12, secondly, the arrangement and the number of the pipes 35 when viewed from the axial direction Da are temporarily set as one of the provisional arrangement conditions. More specifically, as illustrated in FIG. 3, the number of rows of the pipes 35 arranged in the vertical direction Dv and the number of stages of the pipes 35 arranged in the width direction Dw are temporarily set as the arrangement and the number of the plurality of pipes 35 constituting the pipe group 31. The number of the pipes 35 when viewed from the axial direction Da is obtained by multiplying the temporarily set number of rows and number of stages of the pipes 35. Here, since the pipes 35 are folded back in a U-shape in the pipe group 31, the number of the pipes 35 is preferably an even number.

[0044] In this way, by temporarily setting the length dimension L1 of the plurality of pipes 35 in the axial direction Da in step S12, a length dimension L2 of the shell main body 21 in the axial direction Da is set. Since the second shell end portion 212 of the shell main body 21 on the second side Da2 in the axial direction Da is disposed with a clearance having a predetermined dimension from the portion where the pipes 35 are folded back in a U-shape, the length dimension L2 is obtained by adding this clearance to the length dimension L1.

[0045] In addition, the interval between the first plate portion 32 and the second plate portion 33 in the vertical direction Dv, that is, a height dimension H of the flow path 30r, is set in accordance with the number of rows of the pipes 35 in the vertical direction Dv temporarily set in step S12 (see FIG. 3). The first plate portion 32 is disposed with a predetermined space from the pipes 35 of the pipe group 31 in the uppermost row in the vertical direction Dv (including a case where the space is 0). The second plate portion 33 is disposed with a predetermined space from the pipes 35 of the pipe group 31 in the lowermost row in the vertical direction Dv (including a case where the space is 0). In this way, the size of the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw is substantially set by temporarily setting the length dimension L1 of the plurality of pipes 35 in the axial direction Da and the number of rows of the pipes 35 in the vertical direction Dv.

[0046] In addition, the width dimension of the first plate portion 32 in the width direction Dw, that is, the width dimension W of the flow path 30r, is set in accordance with the number of stages in the width direction Dw temporarily set in step S12. The width dimension W is set on the basis of the pipe diameter of the plurality of pipes 35 arranged in the temporarily set number of stages in the width direction Dw and the preset interval between the pipes 35.

[0047] In this way, the size of the flow path cross-sectional area of the flow path 30r when viewed from the axial direction Da is substantially set by setting the width dimension W of the flow path 30r through which the pipe group 31 passes and the height dimension H of the flow path 30r in the vertical direction Dv.

[0048] Here, the provisional arrangement conditions described above are preferably set such that the flow velocity of the gas G in the flow path 30r increases. This is because as the flow velocity of the gas G increases, condensed water is less likely to continue to adhere to the outside surface of the pipes 35 when moisture contained in the gas G is condensed. Specifically, when the pipe group 31 is disposed in the shell main body 21 having a perfectly circular cross section, the number of rows of the plurality of pipes 35 in the vertical direction Dv and the number of stages of the plurality of pipes 35 in the width direction Dw are generally equal to each other about the axis O of the shell main body 21. In this case, when viewed from the axial direction Da, the ratio (H/W) of the height dimension H of the flow path 30r through which the pipe group 31 passes to the width dimension W of the flow path 30r is about 1. On the other hand, in step S12 of the present embodiment, the number (the number of rows) of the pipes 35 arranged in the vertical direction Dv is set to be smaller than the number (the number of stages) of the pipes 35 arranged in the width direction Dw. Accordingly, when viewed from the axial direction Da, the ratio (H/W) of the height dimension H of the flow path 30r through which the pipe group 31 passes to the width dimension W of the flow path 30r is less than 1. The ratio (H/W) of the height dimension H of the flow path 30r to the width dimension W of the flow path 30r is preferably 0.7 or less, for example. In this way, by making the height dimension H of the flow path 30r of the flow path 30r relatively small with respect to the width dimension W, the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw becomes small and the flow velocity of the gas G in the flow path 30r increases as compared with a general case where the ratio (H/W) is about 1.

[0049] Further, in step S12, the length dimension L1, in the axial direction Da, of the plurality of pipes 35 constituting the pipe group 31 may be shortened so that the flow velocity of the gas G in the flow path 30r increases. When the length dimension L2 of the shell main body 21 in the axial direction Da is accordingly shortened, the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw becomes small, and the flow velocity of the gas G in the flow path 30r increases.

[0050] In step S13 of setting the flow rate of the cooling medium, the flow rate of the cooling medium flowing through all of the plurality of pipes 35 is set. The flow rate of the cooling medium is temporarily set such that the outlet temperature of the cooling medium estimated on the basis of the arrangement and the number of the pipes 35 satisfies the required value.

[0051] In step S14 of calculating a numerical value related to heat exchange between the gas G and the cooling medium, a numerical value related to the gas G and the cooling medium at the time when heat exchange is performed between the gas G flowing through the flow path 30r and the cooling medium flowing through the plurality of pipes 35 is calculated. In step S14, heat transfer calculation is performed between the gas G flowing through the flow path 30r and the cooling medium flowing through the plurality of pipes 35. Specifically, in step S14, the amount of heat exchange heat at the time of heat exchange between the gas G flowing through the flow path 30r and the cooling medium flowing through the plurality of pipes 35 is calculated. Further, the amount of temperature decrease with respect to the inlet temperature of the gas G, that is, the outlet temperature of the gas G is calculated on the basis of the calculated amount of heat exchange heat. Further, the amount of temperature increase with respect to the inlet temperature of the cooling medium, that is, the outlet temperature of the cooling medium, is calculated on the basis of the calculated amount of heat exchange heat. In addition, the pressure loss of the gas G at the time when the gas G passes through the gaps between the plurality of pipes 35 in the flow path 30r is calculated on the basis of the number, the pipe diameter, and the like of the plurality of pipes 35.

[0052] In step S15 of checking a cooling medium outlet temperature, it is checked whether or not the outlet temperature of the cooling medium calculated in step S14 is less than the required value (allowable temperature) of the outlet temperature of the cooling medium preset in step S11. As a result, when the calculated outlet temperature of the cooling medium exceeds the allowable temperature (No in step S15), the process returns to step S13 and the flow rate of the cooling medium is temporarily set again. Specifically, when the outlet temperature of the cooling medium exceeds the allowable temperature, the flow rate of the cooling medium is temporarily set again to an increased value. In step S15, when the outlet temperature of the cooling medium is equal to or lower than the allowable temperature (Yes in step S15), the set flow rate of the cooling medium is determined and step S16 is performed.

[0053] In step S16 of checking a gas outlet temperature, it is checked whether or not the outlet temperature of the gas G calculated in step S14 is less than the required value (required temperature) of the outlet temperature of the gas G preset in step S11. As a result, when the calculated outlet temperature of the gas G exceeds the required temperature (No in step S16), the process returns to step S12, and the provisional arrangement conditions are temporarily set again so as to increase the contact area between the gas G and the pipes 35 in the flow path 30r. In the present embodiment, for example, the provisional arrangement conditions are temporarily set again so as to increase the number of pipes 35, which is one of the provisional arrangement conditions. Specifically, when the outlet temperature of the gas G exceeds the required temperature, the provisional arrangement conditions are temporarily set so as to increase the number of rows and the number of stages of the pipes 35. In step S16, when the outlet temperature of the gas G is equal to or lower than the required temperature (Yes in step S16), the process proceeds to step S17.

[0054] In step S17 of checking a gas pressure loss, it is checked whether or not the pressure loss of the gas G calculated in step S14 is greater than the required value (required pressure loss) of the pressure loss of the gas G preset in step S11. As a result, when the pressure loss of the gas G is equal to or greater than the required pressure loss (No in step S17), the process returns to step S12, and the provisional arrangement conditions are temporarily set again so as to reduce the flow velocity of the gas G in the flow path 30r. In the present embodiment, for example, the provisional arrangement conditions are temporarily set again by adjusting the number of pipes 35, which is one of the provisional arrangement conditions. Specifically, when the pressure loss of the gas G exceeds the required pressure loss, the provisional arrangement conditions are temporarily set so as to reduce the pressure loss due to the flow of the gas G in the flow path 30r by increasing the number of rows of the pipes 35, decreasing the number of stages of the pipes 35, or changing the arrangement of the pipes 35. In step S17, when the pressure loss of the gas G is equal to or less than the required pressure loss (Yes in step S17), the set number of rows, number of stages, and arrangement of the pipes 35 are determined, and the process proceeds to step S18.

[0055] In step S18 of acquiring the relationship between the adhesion rate of condensed water and the decrease rate of the efficiency of heat exchange, the relationship between the adhesion rate of condensed water of moisture contained in the gas G to the outside surface of the pipes 35 and the decrease rate of the efficiency of heat exchange between the gas G and the cooling medium is acquired. The relationship between the adhesion rate of condensed water and the decrease rate of the efficiency of heat exchange of the present embodiment is acquired as a function of the flow velocity of the gas.

[0056] Here, the adhesion rate of condensed water is the adhesion rate, per unit area, of condensed water to the outside surface of the pipes 35. The generation rate of condensed water has a correlation with a pipe group passage flow velocity to be described later. Specifically, as the flow velocity (pipe group passage flow velocity) of the gas G passing through the pipe group 31 in the flow path 30r becomes higher, the adhesion rate of condensed water of moisture contained in the gas G to the outside surface of the pipes 35 becomes lower. The condensed water is generated when moisture contained in the gas G is condensed by heat exchange with the cooling medium. Further, the decrease rate of the efficiency of heat exchange is the decrease rate of the efficiency of heat exchange between the gas G and the cooling medium caused when condensed water adheres to the outside surface of the pipes 35 as a liquid film, with reference to a state in which no condensed water adheres to the pipes 35. The decrease rate of the efficiency of heat exchange decreases as the adhesion rate of condensed water decreases, and increases as the adhesion rate of condensed water increases. That is, if no condensed water adheres to the pipes 35, the decrease rate of the efficiency of heat exchange between the gas G and the cooling medium is 0 (zero).

[0057] Specifically, in step S18, first, a pipe group passage flow velocity, which is the flow velocity of the gas G when passing around the plurality of pipes 35 in the flow path 30r, is calculated. The pipe group passage flow velocity of the gas G is calculated on the basis of information on the conditions of the gas G and information on the conditions of the cooling medium set (acquired) in step S11, and the provisional arrangement conditions temporarily set in step S12 and thereafter determined through steps S13 to S17. As indicated in FIG. 5, the relationship between the pipe group passage flow velocity and the decrease amount of the efficiency of heat exchange is acquired as a function F of the calculated pipe group passage flow velocity. In FIG. 5, the decrease amount of the efficiency of heat exchange decreases as the pipe group passage flow velocity increases. Examples of the function F include a function that uses a Weber number (We number) obtained from the relationship between the pipe group passage flow velocity and the surface tension of water. In addition, a Reynolds number (Re number) obtained from the relationship between the pipe group passage flow velocity, the pipe group diameter, and the coefficient of kinematic viscosity may also be used. As described above, the function F is acquired as a function indicating the relationship between the adhesion rate of condensed water and the decrease rate of the efficiency of heat exchange.

[0058] In step S18, the decrease amount of the efficiency of heat exchange between the gas G and the cooling medium is calculated from the pipe group passage flow velocity corresponding to the adhesion rate of condensed water based on such a function F. The decrease rate of the efficiency of heat exchange is calculated on the basis of the decrease amount of the efficiency of heat exchange. In this way, the relationship between the adhesion rate of condensed water of moisture contained in the gas G on the outside surface of the pipes 35 and the decrease amount of the efficiency of heat exchange between the gas G and the cooling medium is acquired as the relationship between the pipe group passage flow velocity, which is the flow velocity of the gas G, and the decrease amount of the efficiency of heat exchange.

[0059] In step S19 of checking an amount of heat exchange heat in the gas cooler 1, it is determined whether or not the relationship between the adhesion rate of condensed water and the decrease rate of the efficiency of heat exchange satisfies a predetermined reference condition. Specifically, in step S19, first, an amount of heat exchange heat in the gas cooler 1 is calculated on the basis of the decrease amount of the efficiency of heat exchange between the gas G and the cooling medium calculated in step S18. Thereafter, it is checked whether or not the calculated amount of heat exchange heat in the gas cooler 1 satisfies a preset target value of the amount of heat exchange heat. Specifically, the target value of the heat exchange amount is, for example, that the heat exchange amount in the gas cooler 1 has a likelihood with respect to the target. When the amount of heat exchange heat in the gas cooler 1 does not satisfy the target value (No in step S19), the process returns to step S12, the provisional arrangement conditions (the length dimension L1 of the pipes 35 and the number of rows and the number of stages of the pipes 35) are temporarily set again, and the processes in step S13 and the subsequent steps are repeatedly performed. When the amount of heat exchange heat in the gas cooler 1 satisfies the target value (Yes in step S19), the process proceeds to step S20.

[0060] In step S20 of determining the specifications of the gas cooler 1, when the reference condition is satisfied as a result of the determination in step S19, the arrangement of the pipes 35 is determined on the basis of the set provisional arrangement conditions. In step S20 of the present embodiment, when the amount of heat exchange heat in the gas cooler 1 satisfies the target value in step S19, the specifications of the gas cooler 1 are determined on the basis of the provisional arrangement conditions temporarily set in step S12 and the flow rate of the cooling medium temporarily set in step S13. Examples of the specifications of the gas cooler 1 determined here include the specifications of the pipes 35 and the specifications of the shell main body 21. As the specifications of the pipes 35, the length dimension L1 of the pipes 35 in the axial direction Da, the arrangement of the pipes 35, the number of the pipes 35 (the number of rows of the pipes 35 arranged in the vertical direction Dv and the number of stages of the pipes 35 arranged in the width direction Dw), the width dimension W and the height dimension H of the flow path 30r, and the flow rate of the cooling medium are determined.

[0061] As the specifications of the shell main body 21, the shell diameter of the shell main body 21 is determined. The shell diameter of the shell main body 21 is selected from among standard dimensions of the shell main body 21 of a plurality of sizes defined in advance on the basis of the sizes of the cooler 3 in the width direction Dw and the vertical direction Dv determined from the determined number of rows and the determined number of stages of the pipes 35.

[0062] In step S21 of checking the shell diameter of the shell main body 21, it is checked whether or not the shell diameter of the shell main body 21 determined in step S20 is less than a preset allowable shell diameter. As a result, when the shell diameter of the shell main body 21 is equal to or larger than the allowable shell diameter (No in step S21), the process returns to step S12, the number of rows and the number of stages of the pipes 35 are temporarily set as the provisional arrangement conditions, and the processes in step S13 and the subsequent steps are repeatedly performed. On the other hand, when the shell diameter of the shell main body 21 is less than the allowable shell diameter (Yes in step S21), the specifications of the gas cooler 1 determined in step S20 are determined, as they are, as the final specifications of the gas cooler 1. Accordingly, the design of the gas cooler 1 is completed.

(Operational Effects)

[0063] In the method S10 of designing the gas cooler 1 configured as described above, provisional arrangement conditions of the pipes 35 when viewed from the axial direction Da in the flow path 30r are set. In addition, the relationship between the adhesion rate of condensed water of moisture contained in the gas G to the outside surface of the pipes 35 and the decrease rate of the efficiency of heat exchange between the gas G and the cooling medium is acquired on the basis of information on the conditions of the gas G, information on the conditions of the cooling medium, and the set provisional arrangement conditions. Further, when the acquired relationship between the adhesion rate of condensed water and the decrease rate satisfies the reference condition, the arrangement of the pipes 35 is determined on the basis of the provisional arrangement conditions.

[0064] Accordingly, it is possible to dispose the pipes 35 at positions in consideration of the decrease in efficiency of heat exchange due to condensation of moisture contained in the gas G. In the gas cooler 1, when moisture is contained in the gas G flowing around the pipes 35, the moisture is condensed by heat exchange between the cooling medium flowing through the pipes 35 and the gas G. The condensed moisture becomes droplets and adheres to the outside surface of the pipes 35. In a state in which the droplets adhere to the outside surface of the pipes 35, the contact area between the gas G and the outside surface of the pipes 35 decreases, and the heat transfer area for heat exchange between the cooling medium and the gas G decreases. Therefore, as the adhesion rate of condensed water rises and the droplets continue to adhere to the outside surface of the pipes 35, the efficiency of heat exchange decreases. However, in the present embodiment, it is determined whether or not the predetermined reference condition is satisfied after the relationship between the adhesion rate of condensed water and the decrease rate is acquired. As a result, the arrangement of the pipes 35 is determined in consideration of the decrease in efficiency of heat exchange due to condensation of moisture. Accordingly, when heat is exchanged between the cooling medium flowing through the pipes 35 and the gas G in the flow path 30r of the gas G, droplets generated by condensation are prevented from continuing to adhere to the outside surface of the pipes 35. As a result, it is possible to design the gas cooler 1 capable of suppressing a decrease in efficiency of heat exchange due to condensation of water contained in the gas G.

[0065] In addition, in step 18, the relationship between the adhesion rate of condensed water and the decrease rate of the efficiency of heat exchange is acquired as a function F of the pipe group passage flow velocity of the gas G corresponding to the adhesion rate of condensed water. Specifically, the decrease amount of the efficiency of heat exchange corresponding to the pipe group passage flow velocity is calculated on the basis of the function F. The decrease rate of the efficiency of heat exchange is calculated on the basis of the decrease amount of the efficiency of heat exchange. In this way, the relationship between the adhesion rate of condensed water of moisture contained in the gas G to the outside surface of the pipes 35 and the decrease amount of the efficiency of heat exchange between the gas G and the cooling medium is acquired as the relationship between the pipe group passage flow velocity, which is the flow velocity of the gas G, and the decrease amount of the efficiency of heat exchange. In this way, the relationship between the adhesion rate of condensed water and the decrease rate of the efficiency of heat exchange between the gas G and the cooling medium may be grasped as a function of the flow velocity of the gas G. The flow velocity of the gas G may be easily grasped by actual measurement or calculation. That is, it is easier that to directly grasp the adhesion rate of condensed water. Accordingly, it is possible to easily acquire the relationship between the adhesion rate of condensed water and the decrease rate of the efficiency of heat exchange.

[0066] Further, in step S12, the arrangement and the number of the pipes 35 when viewed from the axial direction Da are set as the provisional arrangement conditions. Accordingly, with respect to the gas G flowing through the flow path 30r in the shell main body 21 in the width direction Dw, the arrangement and the number of the pipes 35 when viewed from the axial direction Da may be appropriately set so as to suppress the adhesion rate of condensed water (adhesion rate, per unit area, of condensed water to the outside surface of the pipes 35) due to moisture contained in the gas G.

[0067] In addition, in step S12, the pipes 35 are arranged such that the number (number of rows) of pipes 35 arranged in the vertical direction Dv is smaller than the number (number of stages) of pipes 35 arranged in the width direction Dw. Accordingly, the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw is smaller than that in a case where the same number of pipes 35 are arranged in the width direction Dw and the vertical direction Dv. As a result, the flow velocity of the gas G in the flow path 30r increases. Therefore, even if moisture condenses and adheres to the outside surface of the pipes 35 as droplets, the droplets may be easily flicked off by the gas G. Therefore, it is possible to prevent the droplets generated by condensation from continuing to adhere to the outside surface of the pipes 35. Accordingly, it is possible to design the gas cooler 1 capable of further suppressing a decrease in efficiency of heat exchange due to condensation of water contained in the gas G.

[0068] Further, in step S12, the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw is set as the provisional arrangement conditions. That is, the length dimension L1 of the pipes 35 in the axial direction Da and the width dimension W of the flow path 30r are set. Therefore, not only the arrangement of the pipes 35 but also the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw is directly set. Therefore, it is possible to set the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw with high accuracy so that the flow velocity of the gas G in the flow path 30r becomes high. Therefore, it is possible to design the gas cooler 1 capable of suppressing a decrease in efficiency of heat exchange due to condensation of moisture with high accuracy.

[0069] Further, in step S12, the flow path cross-sectional area of the flow path 30r when viewed from the axial direction Da is set as the provisional arrangement conditions. That is, the width dimension W and the height dimension H of the flow path 30r are set. Therefore, not only the arrangement of the pipes 35 but also the flow path cross-sectional area of the flow path 30r when viewed from the axial direction Da is directly set. Therefore, it is possible to set the flow path cross-sectional area of the flow path 30r when viewed from the axial direction Da with high accuracy so that the flow velocity of the gas G in the flow path 30r becomes high. Therefore, it is possible to design the gas cooler 1 capable of suppressing a decrease in efficiency of heat exchange due to condensation of moisture with high accuracy. In addition, by setting the flow path cross-sectional area of the flow path 30r when viewed from the axial direction Da, it is also possible to approximately set the size of the cross-sectional area of the shell main body 21 when viewed from the axial direction Da. Therefore, when selecting the shell main body 21 in step S21, it is possible to easily select the shell main body 21 close to the standard size.

Other Embodiments

[0070] Although the embodiment of the present disclosure has been described in detail with reference to the accompanying drawings, specific configurations are not limited to the embodiment, and include design changes and the like without departing from the gist of the present disclosure.

[0071] The configuration of the gas cooler 1 is not limited to the configuration in the above embodiment. For example, the gas cooler 1 may have a structure other than the shell 2, the cooler 3, and the partition member 5. Further, the shell 2, the partition member 5, the first plate portion 32, and the second plate portion 33 may have a structure other than that in the above embodiment.

[0072] In addition, the arrangement of the plurality of pipes 35 constituting the pipe group 31 is not limited to the arrangement in the above embodiment. For example, the plurality of pipes 35 are not limited to being arranged in a grid pattern as in the present embodiment, and may be arranged in a staggered pattern.

<Supplementary Notes>

[0073] The method S10 of designing the gas cooler 1 described in the embodiment is grasped as follows, for example. [0074] (1) A first aspect provides a method S10 of designing a gas cooler 1 including a shell main body 21 that is hollow and into which a gas G containing moisture is fed from outside, a flow path-forming section 30 that forms a flow path 30r of the gas G in the shell main body 21, and pipes 35 that are disposed passing through the flow path 30r in the shell main body 21 and through which a cooling medium flows, the method S10 including: a step S11 of acquiring information on a condition of the gas G flowing through the flow path 30r in the shell main body 21 and a condition of the cooling medium flowing through the pipes 35; a step S12 of setting a provisional arrangement condition of the pipes 35 when viewed from a second direction Da intersecting a first direction Dw in which the gas G flows in the flow path 30r; a step S18 of acquiring a relationship between an adhesion rate of condensed water of moisture contained in the gas G to an outside surface of the pipes 35 and a decrease rate of an efficiency of heat exchange between the gas G and the cooling medium on the basis of the acquired information on the condition of the gas G, the acquired information on the condition of the cooling medium, and the set provisional arrangement condition; a step S19 of determining whether or not the relationship between the adhesion rate of the condensed water and the decrease rate satisfies a predetermined reference condition; and a step S20 of determining an arrangement of the pipes 35 on the basis of the provisional arrangement condition when the reference condition is satisfied as a result of the determining.

[0075] Examples of the condition of the gas G include a flow rate of the gas G fed into the shell main body 21 from the inlet nozzle 24, an inlet temperature and an inlet pressure of the gas G at the inlet nozzle 24, an outlet temperature and an outlet pressure of the gas G at the outlet nozzle 25, a pressure loss caused from the inlet to the outlet of the gas G, and an absolute humidity of the gas G (components of the gas G). Examples of the condition of the cooling medium include an inlet temperature of the cooling medium at the inlets of the pipes 35 and an outlet temperature of the cooling medium at the outlets of the pipes 35.

[0076] Accordingly, it is possible to dispose the pipes 35 at positions in consideration of the decrease in efficiency of heat exchange due to condensation of moisture contained in the gas G. In the gas cooler 1, when moisture is contained in the gas G flowing around the pipes 35, the moisture is condensed by heat exchange between the cooling medium flowing through the pipes 35 and the gas G. The condensed moisture becomes droplets and adheres to the outside surface of the pipes 35. In a state in which the droplets adhere to the outside surface of the pipes 35, the contact area between the gas G and the outside surface of the pipes 35 decreases, and the heat transfer area for heat exchange between the cooling medium and the gas G decreases. Therefore, as the adhesion rate of condensed water rises and the droplets continue to adhere to the outside surface of the pipes 35, the efficiency of heat exchange decreases. However, in the present embodiment, it is determined whether or not the predetermined reference condition is satisfied after the relationship between the adhesion rate of condensed water and the decrease rate is acquired. As a result, the arrangement of the pipes 35 is determined in consideration of the decrease in efficiency of heat exchange due to condensation of moisture. Accordingly, when heat is exchanged between the cooling medium flowing through the pipes 35 and the gas G in the flow path 30r of the gas G, droplets generated by condensation are prevented from continuing to adhere to the outside surface of the pipes 35. As a result, it is possible to design the gas cooler 1 capable of suppressing a decrease in efficiency of heat exchange due to condensation of water contained in the gas G. [0077] (2) A second aspect provides the method S10 of designing a gas cooler 1 according to (1), in which the relationship between the adhesion rate of the condensed water and the decrease rate is acquired as a function of a flow velocity of the gas G.

[0078] Accordingly, the relationship between the adhesion rate of condensed water of moisture contained in the gas G to the outside surface of the pipe 35 and the decrease amount of the efficiency of heat exchange between the gas G and the cooling medium is acquired as the relationship between the flow velocity of the gas G and the decrease amount of the efficiency of heat exchange. In this way, the relationship between the adhesion rate of condensed water and the decrease rate of the efficiency of heat exchange between the gas G and the cooling medium may be grasped as a function of the flow velocity of the gas G. The flow velocity of the gas G may be easily grasped by actual measurement or calculation. That is, it is easier that to directly grasp the adhesion rate of condensed water. Accordingly, it is possible to easily acquire the relationship between the adhesion rate of condensed water and the decrease rate of the efficiency of heat exchange. [0079] (3) A third aspect provides the method S10 of designing a gas cooler 1 according to (1) or (2), in which: the shell main body 21 is formed in a tubular shape extending around an axis O extending in the second direction Da; and in the step S12 of setting the provisional arrangement condition, an arrangement and the number of the pipes 35 when viewed from the second direction Da are set as the provisional arrangement condition.

[0080] Accordingly, with respect to the gas G flowing through the flow path 30r in the shell main body 21 in the width direction Dw, the arrangement and the number of the pipes 35 when viewed from the second direction Da may be appropriately set so as to suppress the adhesion rate of condensed water (adhesion rate, per unit area, of condensed water to the outside surface of the pipes 35) due to moisture contained in the gas G. [0081] (4) A fourth aspect provides the method S10 of designing a gas cooler 1 according to (3), in which the number of the pipes 35 arranged in a third direction Dv intersecting the first direction Dw and the second direction Da is smaller than the number of the pipes 35 arranged in the first direction Dw.

[0082] Accordingly, the flow path cross-sectional area of the flow path 30r when viewed from the first direction Dw is smaller than that in a case where the same number of the pipes 35 are arranged in the first direction Dw and the third direction Dv. As a result, the flow velocity of the gas G in the flow path 30r increases. Therefore, even if moisture condenses and adheres to the outside surface of the pipes 35 as droplets, the droplets may be easily flicked off by the gas G. Therefore, it is possible to prevent the droplets generated by condensation from continuing to adhere to the outside surface of the pipes 35. Accordingly, it is possible to design the gas cooler 1 capable of further suppressing a decrease in efficiency of heat exchange due to condensation of water contained in the gas G. [0083] (5) A fifth aspect provides the method S10 of designing a gas cooler 1 according to (3) or (4), in which in the step S12 of setting the provisional arrangement condition, a size of a flow path cross-sectional area of the flow path 30r when viewed from the first direction Dw is set as the provisional arrangement condition.

[0084] Accordingly, the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw is directly set. Therefore, it is possible to set the flow path cross-sectional area of the flow path 30r when viewed from the width direction Dw with high accuracy so that the flow velocity of the gas G in the flow path 30r becomes high. Therefore, it is possible to design the gas cooler 1 capable of suppressing a decrease in efficiency of heat exchange due to condensation of moisture with high accuracy. [0085] (6) A sixth aspect provides the method S10 of designing a gas cooler 1 according to any one of (3) to (5), in which in the step S12 of setting the provisional arrangement condition, a size of a flow path cross-sectional area of the flow path when viewed from the second direction Da is set as the provisional arrangement condition.

[0086] Accordingly, the flow path cross-sectional area of the flow path 30r when viewed from the second direction Da is directly set. Therefore, it is possible to set the flow path cross-sectional area of the flow path 30r when viewed from the second direction Da with high accuracy so that the flow velocity of the gas G in the flow path 30r becomes high. Therefore, it is possible to design the gas cooler 1 capable of suppressing a decrease in efficiency of heat exchange due to condensation of moisture with high accuracy.

Industrial Applicability

[0087] According to the gas cooler design method of the present disclosure, it is possible to suppress a decrease in efficiency of heat exchange due to condensation of water contained in a gas.

REFERENCE SIGNS LIST

[0088] 1 Gas cooler [0089] 2 Shell [0090] 2S Space portion [0091] 3 Cooler [0092] 5 Partition member [0093] 8 Compressor system [0094] 9, 9A, 9B Compressor [0095] 10A Preceding-stage connection pipe [0096] 10B Following-stage connection pipe [0097] 21 Shell main body [0098] 21S First space [0099] 21c Center [0100] 211 First shell end portion [0101] 212 Second shell end portion [0102] 22S Second space [0103] 24 Inlet nozzle [0104] 25 Outlet nozzle [0105] 30 Flow path-forming section [0106] 30r Flow path [0107] 31 Pipe group [0108] 32 First plate portion [0109] 32a End portion [0110] 32b End portion [0111] 33 Second plate portion [0112] 33a End portion [0113] 33b End portion [0114] 35 Pipe [0115] 51 Main partition plate [0116] 51a End portion [0117] 51b End portion [0118] 52 First guide portion [0119] 53 Second guide portion [0120] Da Axial direction (second direction) [0121] Da1 First side (axial direction) [0122] Da2 Second side (axial direction) [0123] Df Gas flow direction [0124] Dv Vertical direction (third direction) [0125] Dw Width direction (first direction) [0126] Dw1 First side (width direction) [0127] Dw2 Second side (width direction) [0128] F of pipe group passage flow velocity function [0129] G Gas [0130] H Height dimension [0131] W Width dimension [0132] L1, L2 Length dimension [0133] O Axis [0134] S10 Gas cooler design method [0135] S11 Step of setting required specifications [0136] S12 Step of setting provisional arrangement conditions [0137] S13 Step of setting flow rate of cooling medium [0138] S14 Step of calculating numerical value related to heat exchange between gas and cooling medium [0139] S15 Step of checking cooling medium outlet temperature [0140] S16 Step of checking gas outlet temperature [0141] S17 Step of checking gas pressure loss [0142] S18 Step of acquiring relationship between adhesion rate of condensed water and decrease rate of efficiency of heat exchange [0143] S19 Step of checking amount of heat exchange heat in gas cooler [0144] S20 Step of determining specifications of gas cooler [0145] S21 Step of checking shell diameter of shell main body