Patent Grant
10907902
The present invention relates to a heat exchanger.
In recent years, energy exhaustion issues and global warming issues have been brought to public attention, and thus it has been desired to achieve high efficiency in a refrigerating cycle of an air conditioner or refrigerator. A heat exchanger which is one of the components in the refrigerating cycle has great influence on performances of the refrigerating cycle, and thus high performance thereof is achieved.
Such a heat exchanger is configured to include a plurality of paths (flow paths for refrigerant) in order to decrease a flow path resistance. It is known that a heat transfer coefficient and pressure loss differ due to physical properties of the refrigerant between the case where the heat exchanger is used as a condenser and the case where the heat exchanger is used as an evaporator.
Because of this, in the case where the heat exchanger is used as a condenser and the case where the heat exchanger is used as an evaporator, there is the number of paths most suitable for maximizing a heat exchanging efficiency, respectively.
For example, an air conditioner described in claim 2 in Patent Literature 1 is configured such that “in a case where the heat exchanger is used as an evaporator at the time of heating, it has a branching part that branches, as seen from the upstream side in a flow direction of refrigerant, from an exit of piping of the N-th row (N≥1) into an entrance of piping of the (N+1)-th row and an entrance of piping of the (N+2)-th row, and the amount of refrigerant flowing in the piping of the (N+1)-th row is made larger than the amount of refrigerant flowing in the piping of the (N+2)-th row”. That is, when used as an evaporator, the number of paths is set to be larger on the downstream side forming a domain in which gas is dominant.
This allows the air conditioner described in Patent Literature 1 to make it possible to “improve heat transfer coefficients of the heat transfer pipe for heat exchanger and the refrigerant” when the heat exchanger in the outdoor machine is used as a condenser during cooling operation or the like. Moreover, the air conditioner makes it possible to “avoid malfunction due to frost formation” when the heat exchanger in the outdoor machine is used as an evaporator during heating operation or the like (see paragraphs [0026]-[0027] in Patent Literature 1).
Moreover, a heat exchanger for refrigerator described in the abstract in Patent Literature 2 is configured such that “the heat exchanger composed of a plurality of rows of heat exchangers allows the number of refrigerant paths 19, 20, 21, 22 communicating the heat exchangers 16, 17, 18 with each other to be made smaller as the refrigerant goes toward the outlet side 12b of the gas cooler 12 from the inlet side 12a, and the number of outlets and inlets of the refrigerant paths of the heat exchangers 16, 17, 18 is changed”.
This allows the heat exchanger for refrigerator described in Patent Literature 2 to make it possible to “maintain the refrigerant flowing through each heat exchanger at the flow velocity suitable for heat exchange, depending on an increase in refrigerant density associated with the temperature level of the refrigerant, thereby enhancing a heat exchanging efficiency” (see paragraph [0033] in Patent Literature 2).
Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2007-327707
Patent Literature 2: Japanese Unexamined Patent Application Publication No. 2000-304380
The air conditioner described in Patent Literature 1 allows the branching and merging parts to be provided in the refrigerant paths in the heat exchanger and allows the number of refrigerant paths to be changed as described above, between the domain in which gas is dominant, and the domain in which liquid is dominant, thereby improving a heat exchanging efficiency of the heat exchanger.
Incidentally, the air conditioner described in Patent Literature 1 allows the number of times of merging to be one time (see FIG. 4 in Patent Literature 1). Because of this, when the heat exchanger functions, for example, as a condenser at the time of low load, there has been room for further improvement as to fully increasing the flow velocity of refrigerant in the domain in which the liquid phase refrigerant is dominant, to enhance a heat exchanging efficiency of the heat exchanger.
While on the other hand, the heat exchanger for refrigerator described in Patent Literature 2 allows the branching and merging part to be provided twice (see FIG. 1 in Patent Literature 2). Because of this, when the heat exchanger is used as a condenser, the flow velocity of refrigerant can be secured even at the time of low load in the domain in which the liquid phase refrigerant is dominant.
However, since the branching and merging parts are provided at boundary parts between each row of the fin plates of the heat exchanger, the number of rows of fin plates of the heat exchanger needs to be set to three or more in order to carry out the merging twice. This has caused a problem in that an installation space of the heat exchanger is enlarged.
Moreover, the respective branching and merging parts are located at the upper end or lower end of the heat transfer pipe which is communicated with the next refrigerant path after the merging. Consequently, in the respective branching and merging parts, distances of respective refrigerant paths, taken until flowing into the branching and merging parts, that is, refrigerant flow path lengths do not become equal to each other. Accordingly, the three-forked shape of the branching and merging part becomes asymmetrical (see FIG. 1 in Patent Literature 2).
Moreover, due to the three-forked shape of the branching and merging part being asymmetrical, the refrigerant is not equally distributed at the branching and merging part to allow the refrigerant to generate deflected flow in the refrigerant path on one side. Furthermore, the branching and merging part includes a large number of bend sections and thus is complicated in shape, leading to an increase in production cost of the branching and merging part. In addition, since the branching and merging part is provided twice, demerits such as deflected flow of the refrigerant and an increase in cost become more remarkable.
The present invention has therefore been made in view of the above problems, and it is an object of the present invention to provide a heat exchanger capable of improving performances when functioning as a condenser and as an evaporator.
In order to solve the above problems, the present invention provides, as one aspect thereof, a heat exchanger of fin-plate type used in an outdoor unit or indoor unit of an air conditioner, including: a gas-side port connected to piping through which a gaseous refrigerant flows; a liquid-side port connected to piping through which a liquid refrigerant flows; a refrigerant path that links the gas-side port to the liquid-side port; at least four heat exchange part regions that perform heat exchange between air and the refrigerant flowing through the refrigerant path; and a branching and merging part that branches and merges the refrigerant path to connect the heat exchange part regions in series between the gas-side port and the liquid-side port through the refrigerant path, wherein the heat exchange part regions are connected to each other through the branching and merging part so as to allow the number of refrigerant paths provided in the heat exchange part region near the gas-side port to be greater than the number of refrigerant paths provided in the heat exchange part region near the liquid-side port.
The present invention makes it possible to provide a heat exchanger capable of improving performances when functioning as a condenser and as an evaporator.
Hereinafter, a heat exchanger according to one embodiment of the present invention will be described in detail.
Note that description is given below, as an example, of a case where the heat exchanger according to one embodiment is provided in an air conditioner. However, the heat exchanger according to one embodiment of the present invention is not particularly limited to the above example, and can be applied to every cooling and heating device provided with a refrigerating cycle other than the air conditioner.
Moreover, so long as there is no particular remark in the description below, a refrigerant or refrigerating cycle means a refrigerant or refrigerating cycle that can be used in cooling or heating, or in both of cooling and heating.
Furthermore, for convenience of explanation, the common member in each of the drawings is given the same reference sign and thus repetitive description thereof is omitted. As for directional axes with respect to front, behind, upper, lower, right, left, one end, the other end, and the like, they depend on description in each figure.
Here, an air conditioner 100 including the heat exchanger according to one embodiment of the present invention is adapted to allow an outdoor machine 100A and an indoor machine 1008 to be connected through refrigerant pipings 100V, 100L or the like, and to circulate refrigerant in the circuit to thereby enable indoor air-conditioning.
As shown in
The outdoor machine 100A (outdoor unit) includes a compressor 1, a four-way valve 2 that serves a function of switching a flow path direction of refrigerant between during cooling operation and during heating operation, and a cross fin tube type outdoor heat exchanger 3 (details will be described below). The outdoor machine 100A also includes a blower 4 that feeds air into the heat exchanger 3, and an expansion valve 5 that serves as a decompression device on the outdoor machine 100A side.
Moreover, the indoor machine 100B (indoor unit) includes an expansion valve 6 that serves as a decompression device on the indoor machine 100B side, a cross fin tube type indoor heat exchanger 7, and a blower 8 that feeds air into the heat exchanger 7.
Note that in
The refrigerant piping 100L allows a liquid refrigerant of nearly liquid phase to flow through the inside thereof. Moreover, the refrigerant piping 100V allows a gaseous refrigerant of nearly vapor phase to flow through the inside thereof.
Moreover, when the four-way valve 2 is switched to change the heating and cooling operating states, the heat exchanger 3 of the outdoor machine 100A and the heat exchanger 7 of the indoor machine 100B switch between functions as a condenser and as an evaporator.
Concretely, when the four-way valve 2 is in a state during cooling operation shown in
Moreover, when the four-way valve 2 is in a state (not shown) during heating operation, the heat exchanger 3 functions as an evaporator and allows cold of the liquid refrigerant to radiate heat to be evaporated into the gaseous refrigerant. On the other hand, the heat exchanger 7 functions as a condenser and allows the gaseous refrigerant to radiate heat to be condensed into the liquid refrigerant.
Next, with reference to
Note that in the description below, the refrigerant path means, in the heat exchanger 3 including a plurality of rows of fin plates 11A, 11B, . . . (also see
As described above, for example, the air conditioner 100 exclusive for cooling provided with a refrigerating cycle and the air conditioner 100 exclusive for heating of a heat pump type are different from each other in that the outdoor and indoor heat exchangers 3, 7 each function as a condenser or function as an evaporator during cooling operation and during heating operation.
In recent years, it is known that, particularly in the case where the heat exchanger 3 in the outdoor machine 100A functions as a condenser at the time of low load, performance improvement such as a heat exchanging efficiency and energy consumption efficiency COP greatly contributes to energy saving throughout the year.
In order to aim at actualization of energy saving throughout the year and to efficiently use the heat exchanger 3, it is generally desirable for the number of refrigerant paths in the heat exchanger 3, taking the graph shown in
Here, a heat transfer pipe used in the refrigerant flow path in the heat exchanger 3 generally has the shape of a thin tubular pipe. Moreover, the respective refrigerant paths are configured to communicate the internal fin plates 11A, 11B, . . . composing the heat exchanger 3 with each other (also see
More specifically, when the heat exchanger 3 functions as a condenser, a density of the refrigerant becomes high as compared to the case where the heat exchanger 3 functions as an evaporator. Consequently, the flow velocity of the refrigerant becomes low (a pressure loss is reduced at this time). Moreover, at the time of low load, the amount of refrigerant flowing through the condenser becomes smaller than at the time of high load. In other words, it is desirable to set the number of refrigerant paths to be smaller than that at the time of high load in order to increase the flow velocity of the refrigerant with small flow and high density to increase a heat exchanging efficiency of the heat exchanger 3.
While on the other hand, when the heat exchanger 3 functions as an evaporator, the density of the refrigerant becomes low as compared to the case where the heat exchanger 3 functions as a condenser. Consequently, the flow velocity of the refrigerant becomes high (the pressure loss becomes increased at this time). Therefore, it is desirable to make the number of refrigerant paths larger than that in the case where the heat exchanger 3 functions as a condenser, in order to decrease the flow velocity of the refrigerant to reduce the pressure loss and to increase the heat exchanging efficiency of the heat exchanger 3. When thus configured, the heat exchanging efficiency of the heat exchanger 3 can be maximized.
Note that the compressor 1 cannot keep predetermined discharge when the pressure loss in the heat exchanger 3 becomes increased. Therefore, when the heat exchanger 3 functions as an evaporator, the number of refrigerant paths is made large to decrease the flow velocity of the refrigerant, thereby making it possible to keep discharging capability of the compressor 1.
Summarizing the above, when the heat exchanger 3 functions as a condenser, it is desirable to set the number of refrigerant paths to be smaller than that in the case where the heat exchanger 3 functions as an evaporator, in order to increase the flow velocity of the refrigerant flowing in the heat transfer pipes. At this time, the efficiency of the heat exchanger 3 becomes the maximum and thus the energy consumption efficiency COP of the air conditioner 100 also becomes the maximum (see the broken line in
Moreover, when the heat exchanger 3 functions as an evaporator, it is desirable to set the number of refrigerant paths to be larger than that in the case where the heat exchanger 3 functions as a condenser, in order to decrease the flow velocity of the refrigerant flowing in the heat transfer pipes. At this time, the efficiency of the heat exchanger 3 becomes the maximum and thus the energy consumption efficiency COP of the air conditioner 100 also becomes the maximum (see the dashed line in
Next, with reference to a schematic diagram shown in
The heat exchanger 3A is, for example, a cross fin tube type heat exchanger 3, and includes fin plates 11A, 11B each having a plurality of aluminum fins 10 arranged in a thickness direction thereof, and a refrigerant piping 20.
Note that reference sign 20 generically names every heat transfer pipe to be described below. Moreover, the refrigerant piping 20 visible on the surface side of the paper in
As described above, the refrigerant piping 20 composes a flow path through which the refrigerant flows, and has a form such that it penetrates the fins 10 (each of the fin plates 11A, 11B) in a direction to the back of the paper in
Moreover, the refrigerant piping 20 is provided with a header 12 to which at least four heat transfer pipes 20a, 21a, 22a, 23a are connected, and connected to one end of the fin plate 11A (the left end in
The heat transfer pipe 20a extends from the header 12 to the fin plate 11A and penetrates the fin plate 11A from one end side to the other end side in the right-left direction in
A branching and merging part 24a is, for example, three-forked and disposed between the heat transfer pipe 20a and the heat transfer pipe 21a. Moreover, two sections among the three-forked sections penetrate the fin plate 11A, respectively, from one end side to the other end side in the right-left direction in
A heat transfer pipe 25a has a nearly U-shape, and in a side view of
A heat transfer pipe 26a penetrates the fin plate 11B from one end side to the other end side in the right-left direction in
Moreover, the heat transfer pipe 22a penetrates the fin plate 11A from one end side to the other end side in the right-left direction in
Moreover, the heat transfer pipe 23a penetrates the fin plate 11A from one end side to the other end side in the right-left direction in
A branching and merging part 24b is, for example, three-forked and located between the heat transfer pipe 22a and the heat transfer pipe 23a, and two sections among the three-forked sections penetrate the fin plate 11A from one end side to the other end side to be connected to one end side of the return bend 32a and the other end side of the return bend 32b, respectively. Moreover, the branching and merging part 24b allows the remaining one section to penetrate the fin plate 11B from one end side to the other end side to be connected to one end side of the return bend 32c.
A heat transfer pipe 25b has a nearly U-shape, and in a side view of
A heat transfer pipe 27a is located below the heat transfer pipe 23a and penetrates the fin plate 11A from one end side to the other end side to be connected to the other end side of the return bend 33a. Moreover, a heat transfer pipe 27b is located below the heat transfer pipe 27a and penetrates the fin plate 11A from one end side to the other end side to be connected to one end side of the return bend 33b.
A branching and merging part 24c is, for example, three-forked and located between the heat transfer pipe 27a and the heat transfer pipe 27b, and two sections among the three-forked sections penetrate the fin plate 11A from one end side to the other end side to be connected to one end side of the return bend 33a and the other end side of the return bend 33b, respectively. Moreover, the branching and merging part 24c allows the remaining one section to penetrate the fin plate 11B from one end side to the other end side to be connected to one end side of the return bend 33c.
A heat transfer pipe 25c has a nearly U-shape, and in a side view of
Moreover, the heat transfer pipes 26a and 27a are connected to each other through a connection pipe 35a (see
Note that, as described above, the refrigerant path in the heat exchanger 3 according to each of embodiments of the present invention means, in the heat exchanger 3 including a plurality of rows of fin plates 11A, 11B, . . . , a path (passage) that communicates each row of fin plates 11A, 11B, . . . with each other.
Moreover, the number of refrigerant paths in the present embodiment means the number of independent refrigerant paths. That is, the number of refrigerant paths in the present embodiment corresponds to the number of flow paths that are communicated with rows of fin plates 11A, 11B, . . . such that one end is different from the other end in the refrigerant piping 20. More specifically, the number of refrigerant paths corresponds to the number of flow paths that communicate each row of fin plates 11A, 11B, . . . with each other through flow paths including any of the heat transfer pipes 20a˜23a, the branching and merging parts 24a˜24c, or the connection pipes 35a, 35b. That is, when the number of refrigerant paths is counted in the present embodiment, for convenience explanation, the number of the heat transfer pipes 20a˜23a, the branching and merging parts 24a˜24c, or the connection pipes 35a, 35b should be counted.
In the above configuration, for example, refrigerant which flows through a gate 40 into the header 12 of the heat exchanger 3A that functions as a condenser, is eventually merged into one path from N paths (N is a natural number) in the process of flowing through the refrigerant path of the refrigerant piping 20, and flows through a gate 41 into the expansion valve 5 (see
Moreover, conversely in the same way, for example, refrigerant which flows through the gate 41 into a heat transfer pipe 28a of the heat exchanger 3A that functions as an evaporator, is eventually branched into N paths (N is a natural number) from one path in the process of flowing through the refrigerant path of the refrigerant piping 20, and flows through the gate 40 into the four-way valve 2 (see
Further, with reference to the schematic diagram shown in
As indicated by a thick solid line in
In other words, the plurality of rows of fin plates 11A, 11B includes at least four heat exchange part regions HE1a˜HE2b.
Among these regions, the first upper heat exchange part region HE1a is, in the fin plate 11A, a heat exchange part region on the upper side where the heat transfer pipes 20a˜23a communicated with the header 12 are disposed.
Moreover, the first lower heat exchange part region HE2a is, in the fin plate 11A, a region on the lower side than the heat transfer pipe 23a that is communicated with the header 12 and disposed at the lowermost position, namely, a heat exchange part region on the lower side including the heat transfer pipe 27a to which the connection pipe 35a is connected.
Similarly, the second upper heat exchange part region HE1b is, in the fin plate 11B, a heat exchange part region on the upper side including the position at which the branching and merging part 24b disposed at the lowermost position among the branching and merging parts 24a, 24b in the first round is disposed. Namely, the second upper heat exchange part region HE1b is, in the fin plate 11B, a heat exchange part region on the upper side than the position at which the heat transfer pipe 28a after having passed through the branching and merging part 24c in the second round is disposed.
Moreover, the second lower heat exchange part region HE2b is, in the fin plate 11B, a heat exchange part region on the lower side than the branching and merging part 24b that is disposed at the lowermost position among the branching and merging parts 24a, 24b in the first round. Namely, the second lower heat exchange part region HE2b is, in the fin plate 11B, a heat exchange part region on the lower side including the heat transfer pipe 28a after having passed through the branching and merging part 24c in the second round.
The heat exchanger 3A allows the branching and merging parts 24a, 24b to be disposed, among the four sectioned heat exchange part regions HE1a˜HE2b, at places where the refrigerant flows out of the first upper heat exchange part region HE1a and the refrigerant flows into the second upper heat exchange part region HE1b. That is, the heat exchanger 3A is provided with the branching and merging parts 24a, 24b at the upstream side of the connection pipes 35a, 35b.
Moreover, the heat exchanger 3A allows the branching and merging part 24c to be disposed at a place where the refrigerant flows out of the first lower heat exchange part region HE2a and the refrigerant flows into the second lower heat exchange part region HE2b. That is, the heat exchanger 3A is provided with the branching and merging part 24c at the downstream side of the connection pipes 35a, 35b.
Furthermore, the heat exchanger 3A allows the connection pipes 35a, 35b to be disposed at places where the refrigerant flows out of the second upper heat exchange part region HE1b and the refrigerant flows into the first lower heat exchange part region HE2a.
In other words, the heat exchanger 3A has a flow path passing through the branching and merging parts 24a˜24c and a flow path not passing through the branching and merging parts 24a˜24c when the refrigerant flows out of one of the heat exchange part regions HE1a˜HE2b into another of the heat exchange part regions HE1a˜HE2b. Note that the flow path not passing through the branching and merging parts 24a˜24c means, specifically, a flow path passing through the connection pipes 35a, 35b.
Providing the branching and merging parts 24a, 24b, 24c and the connection pipes 35a, 35b in this way makes it possible for the heat exchanger 3A according to the present embodiment to change the number of paths of the refrigerant piping 20 at a boundary between each row, and at a boundary between the upper and lower parts, of the fin plates 11A and 11B.
More specifically, the path arrangement in the heat exchanger 3A has, for example, when functioning as a condenser, four paths of the heat transfer pipes 20a˜23a at the inlet side of the first upper heat exchange part region HE1a. The path arrangement further has two paths of the branching and merging parts 24a, 24b at the boundaries between the fin plates 11A and 11B in an upper heat exchange part region HE1 located at the upstream side of the connection pipes 35a, 35b. The path arrangement further has two paths of the connection pipes 35a, 35b at the boundaries between the fin plates 11A and 11B. The path arrangement further has one path of the branching and merging part 24c at the boundary between the fin plates 11A and 11B in a lower heat exchange part region HE2 located at the downstream side of the connection pipes 35a, 35b. The path arrangement further has one path at the outlet side of the second lower heat exchange part region HE2b to the gate 41. Thus, the path arrangement is set to gradually decrease the number of paths with a change of four paths→ two paths→ two paths→ one path→ one path, from the inlet side to the outlet side.
Restating the above, the heat exchanger 3A according to the present embodiment is the heat exchanger 3, 7 of fin-plate type 11A, 11B, . . . used in the outdoor unit 100A, or the indoor unit 100B, of the air conditioner 100. The heat exchanger 3A includes the gas-side port (gate 40) connected to the piping through which the gaseous refrigerant flows, the liquid-side port (gate 41) connected to the piping through which the liquid refrigerant flows, and the refrigerant path that links the gas-side port to the liquid-side port. The heat exchanger 3A further includes at least four heat exchange part regions HE1a˜HE2b that perform heat exchange between air and the refrigerant flowing through the refrigerant path, and the branching and merging part 24 (24a˜24c) that branches and merges the refrigerant path to connect the heat exchange part regions HE1a˜HE2b in series between the gas-side port (gate 40) and the liquid-side port (gate 41) through the refrigerant path.
Moreover, the heat exchange part regions HE1a˜HE2b are connected to each other through the branching and merging part 24 so as to allow the number of refrigerant paths (heat transfer pipes 20a˜23a) provided in the heat exchange part region HE1a nearest the gas-side port (gate 40) to be greater than the number of refrigerant paths (heat transfer pipe 28a) provided in the heat exchange part region HE2b nearest the liquid-side port (gate 41).
Moreover, the heat exchange part region HE1a nearest the gas-side port (gate 40) is provided above the heat exchange part region HE2b nearest the liquid-side port (gate 41).
Furthermore, in the case where the heat exchanger 3A functions as a condenser, the branching and merging parts 24a˜24c are provided to allow the number of refrigerant paths to be decreased when the refrigerant flows out of one heat exchange part region HE1a into another heat exchange part region HE1b among the heat exchange part regions HE1a˜HE2b.
Moreover, the refrigerant to flow through the refrigerant piping 20 in the heat exchanger 3A flows in through one heat exchange part region HE1a in the upper heat exchange part region HE1, then flows through another adjacent heat exchange part region HE1b in the upper heat exchange part region HE1, then flows through the connection pipes 35a, 35b into one heat exchange part region HE2a in the lower heat exchange part region HE2, then flows through another adjacent heat exchange part region HE2b in the lower heat exchange part region HE2, and flows out.
Note that the same thing as the case of the condenser described above applies to the case where the heat exchanger 3A functions as an evaporator, too. In this case, the heat exchanger 3A is provided with the branching and merging parts 24a˜24c so as to allow the number of refrigerant paths to be increased when the refrigerant flows out of one heat exchange part region HE1a of the heat exchange part regions HE1a˜HE2b into the other heat exchange part region HE1b.
Incidentally, refrigerant generally causes phase transition between gas phase and liquid phase inside the heat exchanger 3A. Since a gas phase refrigerant has a low density even with the same mass flow rate as compared to a liquid phase refrigerant, the flow velocity of the gas phase refrigerant becomes high approximately ten times or more as compared to the flow velocity of the liquid phase refrigerant.
As a result, the pressure loss is increased due to increase in the flow velocity in a domain in which the gas phase refrigerant is dominant, thereby becoming easy to cause lowering of the heat exchanging efficiency. Moreover, the heat transfer coefficient is lowered due to decrease in the flow velocity in a domain in which the liquid phase refrigerant is dominant, thereby becoming easy to cause lowering of the heat exchanging efficiency.
Therefore, when the heat exchanger 3A functions as a condenser, the path arrangement is set to irregularly and gradually decrease the number of paths as described above, thereby making it possible, in the domain in which the gas phase refrigerant is dominant, to increase the number of paths to decrease the flow velocity and thus to prevent increase in the pressure loss.
Moreover, in the domain in which the liquid phase refrigerant is dominant, the number of paths is decreased from four paths at the inlet side to one path at the outlet side, i.e., the number of paths is decreased to one quarter, thereby making it possible to increase the flow velocity and thus to achieve improvement in the heat transfer coefficient.
Further, when the heat exchanger 3A functions as an evaporator, the number of paths can be increased from one path at the inlet side during use as an evaporator (the outlet side during use as a condenser) to four paths at the outlet side during use as an evaporator (the inlet side during use as a condenser), i.e., by a factor of four. This makes it possible to prevent the pressure loss from being increased in the domain in which the gas phase refrigerant is dominant.
Incidentally, as a comparative example, for example, the heat exchanger described in Patent Literature 2 allows the branching and merging parts to be provided at places where the heat transfer pipe changes to the respective fin plates of the heat exchanger 16 to the heat exchanger 18, respectively. Because of this, for example, in order to carry out the branching and merging twice, the number of rows of the heat exchanger needs to be set to three or more. This causes a problem in that an installation space of the heat exchanger is enlarged.
Contrary to this, the heat exchanger 3A according to the present embodiment allows the connection pipes 35a, 35b to be connected diagonally in the vertical direction, thereby making it possible to arrange the branching and merging parts 24a˜24c in the upper heat exchange part region HE1 and the lower heat exchange part region HE2, respectively.
This makes it possible, even where the number of rows of the heat exchanger 3A is two, to allow the branching and merging to be carried out twice. In this way, space-saving of an installation space of the heat exchanger 3A can be realized.
Moreover, in the heat exchanger 3A according to the present embodiment, consideration will be given to the case where the heat exchanger 3A functions as a condenser. In this case, a percentage in the vertical direction of the heat exchanger 3A, of the heat transfer pipes 20a˜23a composing the paths of refrigerant flowing into the branching and merging parts 24a, 24b in the first round can be made higher than a percentage in the vertical direction of the heat transfer pipe 28a composing the path of refrigerant flowing out of the branching and merging part 24c in the second round. That is, when “a length in the vertical direction of the fin plate 11A is equal to (=) a length in the vertical direction of the fin plate 11B”, “a length in the vertical direction of the first upper heat exchange part region HE1a is longer than (>) a length in the vertical direction of the second lower heat exchange part region HE2b”.
Further in other words, the heat exchange part regions HE1a˜HE2b are sectioned into at least the upper heat exchange part region HE1 and the lower heat exchange part region HE2, and the length in the vertical direction of the upper heat exchange part region HE1 is longer than the length in the vertical direction of the lower heat exchange part region HE2.
This makes it possible to further increase the number of paths in the domain in which the gas phase refrigerant flowing into the branching and merging parts 24a, 24b in the first round is dominant. That is, the number of heat transfer pipes 20a˜23a can be easily increased to four or more. When thus arranged, the pressure loss can be decreased in the case where the heat exchanger 3A functions especially as an evaporator.
Next,
As shown in
Moreover, the three-forked shape of the branching and merging part 24a˜24c in the heat exchanger 3A has a shape such that the refrigerant is merged and discharged at the merging point P in a direction orthogonal to both of the flow paths RP and SP.
Furthermore, in the three-forked shape of the branching and merging part 24a˜24c in the heat exchanger 3A, a height position in the vertical direction of a point Q, at which the refrigerant flows into the fin plate 11B, is set to be equal to a height of an intermediate position of a line segment connecting between the points R and S.
This allows the refrigerant to be equally distributed and merged at the merging point P of the branching and merging part 24a˜24c, thus making it possible to prevent generation of deflected flow. Moreover, the three-forked part of the branching and merging part 24a˜24c can be formed using materials having a small number of bend sections and easy to be machined. Consequently, an increase in production cost of the branching and merging part 24a˜24c can be prevented.
The heat exchanger 3A according to the first embodiment of the present invention is provided with the plurality of rows of fin plates 11A, 11B. Here, the refrigerant path is defined as a refrigerant flow path (communicating path) that communicates each row of fin plates 11A, 11B with each other. Moreover, the heat exchanger 3A includes in the vertical direction, at least four refrigerant paths 20a˜23a into which the refrigerant flows during use as a condenser, and out of which the refrigerant flows during use as an evaporator.
Furthermore, in the case where the heat exchanger 3A functions, e.g., as a condenser, it is provided with the branching and merging parts 24a˜24c so as to allow the number of paths to be decreased when the refrigerant flows out of one heat exchange part region of at least four sectioned heat exchange part regions HE1a˜HE2b in the heat exchanger 3A into the other heat exchange part region.
When thus configured, the path arrangement can be set to irregularly and gradually decrease the number of paths when the heat exchanger 3A functions as a condenser. Therefore, in the domain in which the gas phase refrigerant is dominant, the number of paths can be increased to decrease the flow velocity and thus increase in the pressure loss can be prevented.
Moreover, in the domain in which the liquid phase refrigerant is dominant, the number of paths can be decreased to increase the flow velocity and thus improvement in the heat transfer coefficient can be achieved.
Further, when the heat exchanger 3A functions as an evaporator, the number of paths at the outlet side during use as an evaporator (the inlet side during use as the condenser) can be increased at least by a factor of four, as compared to the number of paths at the inlet side during use as the evaporator (the outlet side during use as the condenser). This makes it possible to prevent the pressure loss from being increased in the domain in which the gas phase refrigerant is dominant.
Moreover, the heat exchanger 3A according to the present embodiment allows the connection pipes 35a, 35b to be connected diagonally in the vertical direction so as to connect the upper heat exchange part region HE1 and the lower heat exchange part region HE2 to each other. Consequently, the branching and merging parts 24a˜24c can be arranged at appropriate positions in the upper heat exchange part region HE1 and the lower heat exchange part region HE2, respectively.
This makes it possible to decrease the required number of rows of fin plates 11A, 11B, . . . in the heat exchanger 3A and thus to realize space-saving of an installation space of the heat exchanger 3A.
Moreover, the heat exchanger 3A allows “the length in the vertical direction of the first upper heat exchange part region HE1a to be longer than (>) the length in the vertical direction of the second lower heat exchange part region HE2b”.
This makes it possible to easily increase, to four or more, the number of paths in the domain in which the gas phase refrigerant flowing into the branching and merging parts 24a, 24b in the first round is dominant, concretely, the number of heat transfer pipes 20a˜23a. When thus arranged, the pressure loss can be decreased to enhance the heat exchanging efficiency in the case where the heat exchanger 3A functions especially as an evaporator.
Moreover, the heat exchange part region HE1a nearest the gas-side port (gate 40) in the heat exchanger 3A is provided above the heat exchange part region HE2b nearest the liquid-side port (gate 41).
That is, the first upper heat exchange part region HE1a allowing the gas phase refrigerant to be dominant is provided above the second lower heat exchange part region HE2b allowing the liquid phase refrigerant to be dominant.
Arranging in this way causes the liquid phase refrigerant to be easy to accumulate, particularly under the influence of gravity, in the second lower heat exchange part region HE2b provided below the first upper heat exchange part region HE1a. That is, the gas phase refrigerant can be easily accumulated in the first upper heat exchange part region HE1a, and the liquid phase refrigerant can be easily accumulated in the second lower heat exchange part region HE2b. This makes it possible to enhance the heat exchanging efficiency.
Hereinafter, the heat exchanger 3B according to the second embodiment will be described with alternate reference to
The heat exchanger 3A in the first embodiment allows, in the three-forked shape of the branching and merging part 24a˜24c (generically named by reference sign 24), the height position in the vertical direction of the point Q, at which the refrigerant flows into the fin plate 11B, to be set to be equal to the height of the intermediate position of the line segment connecting between the points R and S (see
In contrast, as shown in
Configurations other than this, for example, the shape such that the flow path lengths l, m are equal to each other (l=m), and the shape such that the refrigerant is merged and discharged at the merging point P in a direction orthogonal to both of the flow paths RP and SP, are the same as those in the first embodiment.
Even when thus configured, the same effects as those in the first embodiment can be caused. When such branching and merging parts 24aB˜24cB are used, the branching and merging parts 24aB˜24cB can be located, for example, as shown in
Note that, although description has been given of the example in which the hole at the point Q is formed with the point thereof being displaced upward, the hole at the point Q is not particularly limited to this example, but may be formed with the point thereof being displaced downward. Moreover, a length of the distance T (see
Note that the heat exchanger 3B according to the present embodiment can also be restated in the same manner as in the first embodiment, as follows. That is, the heat exchanger 3B is the heat exchanger 3, 7 of fin-plate type 11A, 11B, . . . used in the outdoor unit 100A, or the indoor unit 100B, of the air conditioner 100. The heat exchanger 3B includes the gas-side port (gate 40) connected to the piping through which the gaseous refrigerant flows, the liquid-side port (gate 41) connected to the piping through which the liquid refrigerant flows, and the refrigerant path that links the gas-side port to the liquid-side port. The heat exchanger 3B further includes at least four heat exchange part regions HE1a˜HE2b that perform heat exchange between air and the refrigerant flowing through the refrigerant path, and the branching and merging part 24B (24aB˜24cB) that branches and merges the refrigerant path to connect the heat exchange part regions HE1a˜HE2b in series between the gas-side port (gate 40) and the liquid-side port (gate 41) through the refrigerant path.
Moreover, the heat exchange part regions HE1a˜HE2b are connected to each other through the branching and merging part 24B (24aB˜24cB) so as to allow the number of refrigerant paths (heat transfer pipes 20a˜23a) provided in the heat exchange part region HE1a nearest the gas-side port (gate 40) to be greater than the number of refrigerant paths (heat transfer pipe 28a) provided in the heat exchange part region HE2b nearest the liquid-side port (gate 41).
Moreover, the heat exchange part region HE1a nearest the gas-side port (gate 40) is provided above the heat exchange part region HE2b nearest the liquid-side port (gate 41).
As for the heat exchanger 3A in the first embodiment, description is given of the case in which it is provided with two rows of fin plates 11A, 11B. However, the number of rows of fin plates is not limited to two. The heat exchanger 3C according to the third embodiment is different from that in the first embodiment in that it is provided with three rows of fin plates 11A, 11B, 11C.
Note that, with arrangement of the fin plates in three rows, heat transfer pipes 37a˜37f (and return bends associated therewith) composing refrigerant paths are arranged, for example, at boundaries between the fin plates 11A, 11B (compare and contrast
Note that, in this case, the upper heat exchange part region HE1 is a region that includes the first upper heat exchange part region HE1a, the second upper heat exchange part region HE1b, and a third upper heat exchange part region HE1c. Here, the first upper heat exchange part region HE1a and the second upper heat exchange part region HE1b are, in the fin plates 11A, 11B, regions on the upper side including the heat transfer pipe 37d. Moreover, the third upper heat exchange part region HE1c is, in the fin plate 11C, a region on the upper side including the branching and merging part 24b.
Moreover, the lower heat exchange part region HE2 is a region that includes the first lower heat exchange part region HE2a, the second lower heat exchange part region HE2b, and a third lower heat exchange part region HE2c. Here, the first lower heat exchange part region HE2a and the second lower heat exchange part region HE2b are, in the fin plates 11A, 11B, regions on the lower side than the heat transfer pipe 37d. Moreover, the third lower heat exchange part region HE2c is, in the fin plate 11C, a region on the lower side than the branching and merging part 24b.
Furthermore, when the number of refrigerant paths is counted in the present embodiment, in the same manner as in the first embodiment, the number of the heat transfer pipes 20a˜23a, the branching and merging parts 24a˜24c, the connection pipes 35a, 35b, or the heat transfer pipes 37a˜37f should be counted.
Here, places at which the heat transfer pipes 37a˜37f composing the refrigerant paths are arranged are not particularly limited to the boundaries between the fin plates 11A, 11B, and configuration may be adopted such that the heat transfer pipes 37a˜37f are arranged at boundaries between the fin plates 11B, 11C. In this case, the branching and merging parts 24a˜24c should be arranged at the boundaries between the fin plates 11A, 11B. That is, the heat transfer pipes 37a˜37f and the branching and merging parts 24a˜24c can be exchanged in the order of arrangement in a thickness direction in front of and behind the heat exchanger 3C (in the right-left direction of the paper in
Even when thus configured, the same effects as those in the first embodiment can be caused. That is, in the same manner as in the first embodiment, the heat exchanger 3C according to the third embodiment allows the branching and merging parts 24a˜24c to be provided once in the upper heat exchange part region HE1 (branching and merging parts 24a, 24b) and once in the lower heat exchange part region HE2 (branching and merging part 24c). In other words, the heat exchanger 3C allows the branching and merging parts 24a˜24c to be provided twice in total between the fin plates 11A and 11B, or between the fin plates 11B and 11C.
Moreover, when the branching and merging parts 24a˜24c are provided, for example, at boundaries between the fin plates 11A, 11B, the number of paths can be changed and increased in a domain in which the gas phase refrigerant is dominant on the side near the gate 40, as compared to a known heat exchanger of three-row type, for example, described in Patent Literature 2. Note that the heat exchanger described in Patent Literature 2 makes it impossible to change the number of paths so long as the number of rows of the fin plates is not increased (see the heat exchanger shown in FIG. 1 in Patent Literature 2).
Incidentally, the case where the branching and merging parts 24a˜24c are provided at boundaries between the fin plates 11A, 11B exhibits path arrangement which makes much account of a decrease in pressure loss in the heat exchanger 3C during heating operation. That is, the heat exchanger 3C thus configured makes it possible to realize specifications suitable for use exclusive for heating operation, as compared to the known heat exchanger of three-row type described in Patent Literature 2.
While on the other hand, as shown in
Incidentally, the case of
Note that the heat exchanger 3C according to the present embodiment can also be restated in the same manner as in the first embodiment, as follows. That is, the heat exchanger 3C is the heat exchanger 3, 7 of fin-plate type 11A, 11B, . . . used in the outdoor unit 100A, or the indoor unit 100B, of the air conditioner 100. The heat exchanger 3C includes the gas-side port (gate 40) connected to the piping through which the gaseous refrigerant flows, the liquid-side port (gate 41) connected to the piping through which the liquid refrigerant flows, and the refrigerant path that links the gas-side port to the liquid-side port. The heat exchanger 3C further includes at least four heat exchange part regions HE1a˜HE2c that perform heat exchange between air and the refrigerant flowing through the refrigerant path, and the branching and merging part 24 (24a˜24c) that branches and merges the refrigerant path to connect the heat exchange part regions HE1a˜HE2c in series between the gas-side port (gate 40) and the liquid-side port (gate 41) through the refrigerant path.
Moreover, the heat exchange part regions HE1a˜HE2c are connected to each other through the branching and merging part 24 so as to allow the number of refrigerant paths (heat transfer pipes 20a˜23a) provided in the heat exchange part region HE1a nearest the gas-side port (gate 40) to be greater than the number of refrigerant paths (heat transfer pipe 28a) provided in the heat exchange part region HE2c nearest the liquid-side port (gate 41).
Moreover, the heat exchange part region HE1a nearest the gas-side port (gate 40) is provided above the heat exchange part region HE2c nearest the liquid-side port (gate 41).
Furthermore, the heat exchanger 3C has a flow path passing through the branching and merging parts 24a˜24c and a flow path not passing through the branching and merging parts 24a˜24c when the refrigerant flows out of one of the heat exchange part regions HE1a˜HE2c into another of the heat exchange part regions HE1a˜HE2c. Note that the flow path not passing through the branching and merging parts 24a˜24c means, specifically, a flow path passing through the connection pipes 35a, 35b and the heat transfer pipes 37a˜37f.
The first embodiment, the second embodiment and the third embodiment described above have been described in detail for explaining the content of the present invention in a plain way, and are not necessarily limited to what is provided with all of the configurations described above.
Also, part of the configuration of one embodiment can be replaced with the configuration of the other embodiment, and part or all of the configuration of one embodiment can also be added to the configuration of the other embodiment.
Moreover, for part of the configuration of each embodiment, the configuration of the other embodiment can also be added to, deleted from, or replaced for.
For example, although description is given of the example in which the branching and merging parts 24 in the heat exchanger 3A, 3B, 3C according to each embodiment of the present invention are three-forked, the branching and merging parts are not particularly limited to this example.
In each embodiment of the present invention as described above, the branching and merging parts 24 in the heat exchanger are all three-forked. Therefore, when the refrigerant flow paths in the heat exchanger according to each embodiment of the present invention are schematically depicted, they exhibit a shape such as shown in
As shown in
Furthermore, the heat exchanger 3 according to each of the embodiments of the present invention may be configured to allow the schematic diagram of refrigerant flow paths to exhibit a nearly pyramidal shape in which a plurality of branching and merging parts 24N are cascade-connected with each other. That is, the schematic diagram of refrigerant flow paths may exhibit a shape in which the N-forked branching and merging parts 24N are arranged stepwise in N stages. Note that in
Moreover, although in the third embodiment, description is given of the case in which the branching and merging parts 24a˜24c are employed, the branching and merging parts 24aB˜24cB in the second embodiment can also be employed in place of the branching and merging parts 24a˜24c.
Furthermore, in the third embodiment, description is given of the modified example in which the branching and merging parts 24a˜24c in both of the upper heat exchange part region HE1 and the lower heat exchange part region HE2 are transferred to boundaries between the fin plates 11A, 11B.
However, configuration may be adopted such that the branching and merging parts 24a, 24b in the upper heat exchange part region HE1, or only the branching and merging part 24c in the lower heat exchange part region HE2 are/is transferred to boundaries between the fin plates 11A, 11B.
That is, the branching and merging parts 24a˜24c may be arranged diagonally through the connection pipes 35a, 35b between different fin plates 11A, 11B, . . . .
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/075752 | 9/10/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2017/042940 | 3/16/2017 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5076353 | Haussmann | Dec 1991 | A |
| 6382310 | Smith | May 2002 | B1 |
| 20100300141 | Fujimoto | Dec 2010 | A1 |
| 20120073786 | Sakashita | Mar 2012 | A1 |
| 20150211802 | Yokozeki | Jul 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 2000-304380 | Nov 2000 | JP |
| 2001-066017 | Mar 2001 | JP |
| 2007-327707 | Dec 2007 | JP |
| 2012-237543 | Dec 2012 | JP |
| 2015-140990 | Aug 2015 | JP |
| 2013084508 | Jun 2013 | WO |
| Entry |
|---|
| Extended European Search Report received in corresponding European Application No. 15903602.9 dated May 15, 2019. |
| International Search Report of PCT/JP2015/075752 dated Feb. 1, 2015. |
| Number | Date | Country | |
|---|---|---|---|
| 20180259265 A1 | Sep 2018 | US |
