Patent Application
20220221232
The present disclosure relates to a heat exchanger forming a condenser or an evaporator of a chiller such as a centrifugal chiller.
In the related art, a shell-tube heat exchanger, a fin-tube heat exchanger, a plate heat exchanger, a plate fin heat exchanger, or the like has been used as a heat exchanger that accompanies fluid phase changes, such as an evaporator or a condenser. The shell-tube heat exchanger is configured to allow a single-phase fluid to flow through a tube, heat and cool an external fluid, and evaporate and condense the external fluid. The fin-tube heat exchanger is configured to allow a gas to flow between fins outside a tube, heat and cool the fluid inside the tube, and evaporate and condense the fluid inside the tube. The plate heat exchanger or the plate fin heat exchanger is configured to allow a single-phase fluid to flow between first plates, heat and cool a fluid between second plates, and evaporate and condense the fluid. Among the heat exchangers, as the plate fin heat exchanger, for example, the following PTLs 1 to 3 have been reported.
In a case where a fluid is evaporated or condensed, the fluid undergoes a phase change, and thus a volume of the fluid changes significantly during a heat exchange process. In particular, in a portion (gas side) of a fluid flow path in which the internal fluid is in a gas phase state, a fluid volume in the fluid flow path becomes very large, and an excessive pressure loss may occur. On the other hand, if a fluid flow path is determined such that an excessive pressure loss does not occur in the flow on the gas side, a flow velocity on a liquid side (a portion where an internal fluid is in a liquid phase state) is significantly reduced, and thus a problem that the heat transfer performance deteriorates occurs.
In the case of the shell-tube heat exchanger, an unequal pitch is used in which a tube pitch and the like are changed such that the heat transfer performance and a pressure loss are appropriate in response to a volume change in the heat exchange process of a fluid. However, in this case, there is a problem that a volume of the shell-tube heat exchanger becomes large and thus an amount of fluids held on a side performing a phase change increases. On the other hand, the fin-tube heat exchanger, the plate heat exchanger, and the plate fin heat exchanger can be made more compact than the shell-tube heat exchanger, but shapes of heat exchangers currently reported do not correspond to a fluid volume change due to the phase change as described above.
The present disclosure has been made in view of such circumstances, and an object thereof is to provide a compact heat exchanger capable of suppressing the occurrence of excessive pressure loss and ensuring an appropriate flow velocity in correspondence to a volume change of a fluid due to a phase change.
In order to solve the above problems, the present disclosure employs the following means.
According to the present disclosure, there is provided a heat exchanger including a flow path having an inflow port through which a fluid flows thereinto and an outflow port through which the fluid having flowed in flows out therefrom, and in which a phase change occurs from a liquid phase to a gas phase between the inflow port and the outflow port, in which a resistance shape is formed inside the flow path such that a magnitude of a flow path resistance applied to a flow of the fluid is smaller on the outflow port side than on the inflow port side.
If the fluid flowing into the flow path undergoes a phase change (evaporated) from a liquid phase to a gas phase through heat exchange in the flow path, a fluid volume increases. In this case, on the outflow port side, an excessive pressure loss may occur due to an increase in the fluid volume. However, in the heat exchanger according to a first aspect of the present disclosure, the resistance shape is formed inside the flow path such that the magnitude of the flow path resistance applied to the flow of the fluid becomes smaller on the outflow port side than on the inflow port side (for example, in five stages). Therefore, on the outflow port side (gas side), the magnitude of the flow path resistance applied to the flow of the fluid is small, and thus the occurrence of excessive pressure loss can be suppressed. On the other hand, on the inflow port side (liquid side), since the magnitude of the flow path resistance applied to the flow of the fluid is large, it is possible to prevent a flow velocity of the fluid from being significantly reduced (that is, an appropriate flow velocity can be ensured) and also to promote turbulence. As described above, in the heat exchanger according to the first aspect of the present disclosure, it is possible to suppress the occurrence of excessive pressure loss and promote turbulence in correspondence to a volume change of the fluid due to a phase change. Therefore, such a heat exchanger is a heat exchanger having high heat transfer performance (evaporation heat transfer performance). Since it is only necessary to form the specific resistance shape inside the flow path, the heat exchanger can be made compact.
According to the present disclosure, there is provided a heat exchanger including a flow path having an inflow port through which a fluid flows thereinto and an outflow port through which the fluid having flowed in flows out therefrom, and in which a phase change occurs from a gas phase to a liquid phase between the inflow port and the outflow port, in which a resistance shape is formed inside the flow path such that a magnitude of a flow path resistance applied to a flow of the fluid is larger on the outflow port side than on the inflow port side.
If the fluid flowing into the flow path undergoes a phase change (condensed) from a gas phase to a liquid phase through heat exchange in the flow path, a fluid volume decreases. In this case, an excessive pressure loss may occur on the inflow port side due to an increase in the fluid volume. However, in the heat exchanger according to a second aspect of the present disclosure, the resistance shape is formed inside the flow path such that the magnitude of the flow path resistance applied to the flow of the fluid becomes larger on the outflow port side than on the inflow port side (for example, in five stages). Therefore, on the inflow port side (gas side), the magnitude of the flow path resistance applied to the fluid flow is small, and thus the occurrence of excessive pressure loss can be suppressed. On the other hand, on the outflow port side (liquid side), since the magnitude of the flow path resistance applied to the flow of the fluid is large, it is possible to prevent a flow velocity of the fluid from being significantly reduced (that is, an appropriate flow velocity can be ensured) and also to promote turbulence. As described above, in the heat exchanger according to the second aspect of the present disclosure, it is possible to suppress the occurrence of excessive pressure loss and promote turbulence in correspondence to a volume change of the fluid due to a phase change. Therefore, such a heat exchanger is a heat exchanger having high heat transfer performance (condensation performance). Since it is only necessary to form the specific resistance shape inside the flow path, the heat exchanger can be made compact.
In the heat exchanger, the resistance shape is preferably formed by a plate forming the flow path or a plurality of fins provided on the plate.
As described above, the resistance shape formed inside the flow path may be formed by the plate forming the flow path (for example, in a plate heat exchanger) or the plurality of fins provided on the plate (for example, in a plate fin heat exchanger). Specifically, in the portion where the flow path resistance is increased, the plates and fins are arranged perpendicular to the fluid flow direction. On the other hand, in a portion where the flow path resistance is reduced, the plates and fins are arranged parallel to the fluid flow direction. With this configuration, the resistance shape can be formed. Therefore, the heat exchangers of the present disclosure are particularly suitably applicable to the plate heat exchanger or the plate fin heat exchanger. Since the plate heat exchanger or the plate fin heat exchanger can be made compact, if the heat exchanger of the present disclosure is applied to the plate heat exchanger or the plate fin heat exchanger, the heat transfer performance is improved and the heat exchanger can be made compact.
The heat exchanger preferably further includes a separate flow path that is provided adjacent to the flow path and is subjected to heat exchange with the fluid flowing through the flow path.
In the heat exchanger of the present disclosure, as described above, the separate flow path is provided, and thus heat exchange can be performed between the fluid flowing through the flow path and the fluid flowing through the separate flow path.
In the heat exchanger, a resistance shape is preferably formed inside the separate flow path such that the same flow path resistance is applied between an inflow port through which a fluid flows thereinto to flow in the separate flow path and an outflow port through which the fluid having flowed in flows out therefrom.
As described above, if the separate flow path in which the internal resistance shape is a resistance shape that applies the constant magnitude of the flow path resistance to the flow of the fluid may be combined with the flow path, the present disclosure is suitably applicable to the heat exchanger having a configuration in which one fluid is in a single phase and the other fluid undergoes a phase change.
In the heat exchanger, a resistance shape is preferably formed inside the separate flow path such that a flow path resistance is smaller at an inflow port through which a fluid flows thereinto to flow in the separate flow path than at an outflow port through which the fluid having flowed in flows out therefrom or is larger than at the inflow port than at the outflow port.
In the heat exchanger of the present disclosure, for example, the flow path in the first aspect and the flow path in the second aspect may be combined with each other. That is, the heat exchanger of the present disclosure is suitably applicable to a heat exchanger in which one fluid is evaporated in the flow path and the other fluid is condensed in the flow path.
The heat exchanger of the present disclosure is a compact heat exchanger that can suppress the occurrence of excessive pressure loss and ensure an appropriate flow velocity in correspondence to a volume change of a fluid due to a phase change.
Hereinafter, an embodiment of a heat exchanger according to the present disclosure will be described with reference to the drawings.
In the following embodiments, a case where the heat exchanger according to the present disclosure is applied to a plate fin heat exchanger will be described as an example.
Hereinafter, a first embodiment of the present disclosure will be described with reference to
A fluid (first fluid) 6 flows into the heat exchanger 1 from the boss 3a, and a fluid (second fluid) 7 flows thereinto from the boss 3b. The first fluid 6 is circulated in a flow path 8 formed between the second plate 2b and the inner fin 5a. The second fluid 7 is circulated in a separate flow path 9 that is formed between the first plate 2a and the inner fin 5b and is adjacent to the flow path 8.
With such a configuration, the heat exchanger 1 has a structure in which the flow path 8 for the first fluid 6 and the separate flow path 9 for the second fluid 7 are alternately disposed and heat exchange occurs between the two fluids 6 and 7.
Next, the flow path 8 of the present embodiment will be described in more detail with reference to
As illustrated in
A resistance shape 12 is formed inside the flow path 8 such that a magnitude of a flow path resistance applied to the flow of the first fluid 6 is smaller on the outflow port 11 side than on the inflow port 10 side. The resistance shape 12 is formed such that the magnitude of the flow path resistance becomes smaller in five stages from the inflow port 10 side to the outflow port 11 side. In the present embodiment, the resistance shape 12 is formed by a plurality of fins 13 provided on the first plate 2a.
Specifically, in a portion (liquid side) where the flow path resistance is increased, the fins 13 are arranged perpendicular to a flow direction of the fluid 6, and a length of the fins 13 (a length in the direction perpendicular to the flow direction of the fluid 6) is reduced from the inflow port 10 side toward the outflow port 11 side. On the other hand, in a portion (gas side) where the flow path resistance is reduced, the fins 13 are arranged parallel to the flow direction of the fluid 6, and are arranged such that the number of fins 13 becomes smaller from the inflow port 10 side toward the outflow port 11 side.
According to the present embodiment, the following effects are achieved by the configuration described above.
In the heat exchanger 1 according to the present embodiment, the resistance shape 12 is formed such that the magnitude of the flow path resistance applied to the flow of the fluid 6 inside the flow path 8 becomes smaller in five stages from the inflow port 10 side to the outflow port 11 side. Therefore, on the outflow port 11 side (gas side), the magnitude of the flow path resistance applied to the flow of the fluid 6 is small, and thus the occurrence of excessive pressure loss can be suppressed. On the other hand, on the inflow port 10 side (liquid side), since the magnitude of the flow path resistance applied to the flow of the fluid 6 is large, it is possible to prevent a flow velocity of the fluid 6 from being significantly reduced (that is, an appropriate flow velocity can be ensured) and also to promote turbulence. As described above, in the heat exchanger 1 according to the present embodiment, it is possible to suppress the occurrence of excessive pressure loss and promote turbulence in correspondence to a volume change of the fluid 6 due to a phase change. Therefore, such a heat exchanger 1 is the heat exchanger 1 having high heat transfer performance (evaporation heat transfer performance). Since it is only necessary to form the specific resistance shape 12 inside the flow path 8, the heat exchanger 1 can be made compact.
The resistance shape 12 formed inside the flow path 8 may be formed by the plurality of fins 13 provided on the first plate 2a (in the plate fin heat exchanger). Therefore, the heat exchanger 1 of the present embodiment is particularly suitably applicable to the plate fin heat exchanger. Since the plate fin heat exchanger can be made compact, if the heat exchanger 1 of the present embodiment is applied to the plate fin heat exchanger, the heat transfer performance is improved and the heat exchanger 1 becomes compact.
The resistance shape 12 may also be formed by the first plate 2a forming the flow path 8 (in the plate heat exchanger). Therefore, the heat exchanger 1 of the present embodiment is also suitably applicable to the plate heat exchanger. Since the plate heat exchanger can also be made compact, if the heat exchanger 1 of the present embodiment is applied to the plate heat exchanger, the heat transfer performance is improved and the heat exchanger 1 becomes compact as described above.
In the present embodiment, as illustrated in
Next, a second embodiment of the present disclosure will be described with reference to
A fundamental configuration of the present embodiment is basically the same as that of the first embodiment, but is different from that of the first embodiment in that a first fluid 26 undergoes a phase change from a gas phase to a liquid phase in a flow path 28, and in terms of a configuration of a resistance shape 22. Therefore, in the present embodiment, this different portion will be described, and the description of other overlapping portions will be omitted.
The same constituents as those in the first embodiment are given the same reference numerals, and the repeated description thereof will be omitted.
In the flow path 28 illustrated in
Specifically, in a portion (gas side) where the flow path resistance is reduced, the fins 13 are arranged parallel to the flow direction of the fluid 26, and are arranged such that the number of the fins 13 becomes larger from the inflow port 10 side toward the outflow port 11 side. On the other hand, in a portion (liquid side) where the flow path resistance is increased, the fins 13 are arranged perpendicular to the flow direction of the fluid 26, and a length of the fins 13 (a length in the direction perpendicular to the flow direction of the fluid 26) is increased from the inflow port 10 side toward the outflow port 11 side.
According to the present embodiment, the following effects are achieved by the configuration described above.
In the heat exchanger 21 according to the present embodiment, the resistance shape 22 is formed such that the magnitude of the flow path resistance applied to the flow of the fluid 26 inside the flow path 28 becomes larger in five stages from the inflow port 10 side to the outflow port 11 side. Therefore, on the inflow port 10 side (gas side), the magnitude of the flow path resistance applied to the flow of the fluid 26 is small, and thus the occurrence of excessive pressure loss can be suppressed. On the other hand, on the outflow port 11 side (liquid side), since the magnitude of the flow path resistance applied to the flow of the fluid 26 is large, it is possible to prevent the flow velocity of the fluid 26 from being significantly reduced (that is, an appropriate flow velocity can be ensured) and also to promote turbulence. As described above, in the heat exchanger 21 according to the present embodiment, it is possible to suppress the occurrence of excessive pressure loss and promote turbulence in correspondence to a volume change of the fluid 26 due to a phase change. Therefore, such a heat exchanger 21 is the heat exchanger 21 having high heat transfer performance (condensation performance). Since it is only necessary to form the specific resistance shape 22 inside the flow path 28, the heat exchanger 21 can be made compact.
In the present embodiment, as illustrated in
Next, a third embodiment of the present disclosure will be described with reference to
A fundamental configuration of the present embodiment is basically the same as that of the second embodiment, but is different from that of the second embodiment in that a resistance shape 42 that applies the same flow path resistance between an inflow port 40 and an outflow port 41 is formed inside a separate flow path 49. Therefore, in the present embodiment, this different portion will be described, and the description of other overlapping portions will be omitted.
The same constituents as those in the second embodiment are given the same reference numerals, and the repeated description thereof will be omitted. In
On the other hand, the separate flow path 49 has the inflow port 40 through which a second fluid 47 flows thereinto and an outflow port 41 through which the second fluid 47 having flowed in flows out therefrom. In the separate flow path 49, the second fluid 47 does not undergo a phase change between the inflow port 40 and the outflow port 41, and is circulated in the separate flow path 49 in a liquid phase (that is, a single phase). The resistance shape 42 that applies the same flow path resistance between the inflow port 40 and the outflow port 41 is formed inside the separate flow path 49.
According to the present embodiment, the following effects are achieved by the configuration described above.
As described above, the separate flow path 49 in which the internal resistance shape 42 is the resistance shape 42 that applies the constant magnitude of the flow path resistance to the flow of the fluid 47 may be combined with the flow path 28 according to the second embodiment described above. That is, the present disclosure is suitably applicable to the heat exchanger 31 having a configuration in which one fluid 47 is in a single phase and the other fluid 26 undergoes a phase change.
Next, a fourth embodiment of the present disclosure will be described with reference to
A fundamental configuration of the present embodiment is basically the same as that of the third embodiment, but is different from that of the third embodiment in terms of a configuration of a resistance shape 52 formed inside a separate flow path 59. Therefore, in the present embodiment, this different portion will be described, and the description of other overlapping portions will be omitted.
The same constituents as those in the third embodiment are given the same reference numerals, and the repeated description thereof will be omitted. In
According to the present embodiment, the following effects are achieved by the configuration described above.
In the heat exchanger 51 of the present embodiment, for example, the flow path 8 (separate flow path 59) in the first embodiment may be combined with the flow path 28 in the second embodiment. That is, the heat exchanger 51 of the present embodiment is suitably applicable to the heat exchanger 51 having a configuration in which one fluid 57 is evaporated in the flow path 8 (separate flow path 59) and the other fluid 26 is condensed in the flow path 28.
In the embodiments described above, the case where the heat exchanger of the present disclosure is applied to the plate fin heat exchanger has been described as an example, but the present disclosure is not limited to this. Specifically, the heat exchanger of the present disclosure is also applicable to a plate heat exchanger, a fin-tube heat exchanger, and the like. The heat exchanger of the present disclosure is preferably applied to a plate heat exchanger or a plate fin heat exchanger.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2019/022629 | 6/6/2019 | WO | 00 |
