HEAT EXCHANGER AND REFRIGERATION AND AIR-CONDITIONING APPARATUS
A heat exchanger includes a first flat pipe including plural through-holes through which a high-temperature fluid flows, a second flat pipe including plural through-holes through which a low-temperature fluid flows, a first tubular shape inlet header connected to one end of the first flat pipe, a first tubular shape outlet header connected to another end of the first flat pipe, a second tubular shape inlet header connected to one end of the second flat pipe, and a second tubular shape outlet header connected to another end of the second flat pipe. The first and second flat pipes are stacked with contacting flat surfaces. The low-temperature fluid flowing into the through-holes in the second flat pipe from the second inlet header is a fluid in a two-phase gas-liquid state, and flows into those through-holes in a substantially horizontal direction or in an upward direction relative to the substantially horizontal direction.
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The present invention relates to a heat exchanger that exchanges heat between a low-temperature fluid and a high-temperature fluid so as to transfer the heat from the high-temperature fluid to the low-temperature fluid. Moreover, the present invention relates to a refrigeration and air-conditioning apparatus equipped with the heat exchanger.
BACKGROUND ARTA heat exchanger in the related art includes a first passage section having a plurality of through-holes through which a low-temperature fluid flows, a second passage section having a plurality of through-holes through which a high-temperature fluid flows, first headers connected to both ends of the first passage section, and second headers connected to both ends of the second passage section. The first passage section and the second passage section are stacked with surfaces thereof in contact with each other such that longitudinal directions (i.e., fluid flowing directions) thereof are parallel to each other. Moreover, at least one of the high-temperature fluid and the low-temperature fluid is a fluid in a two-phase gas-liquid state. An inlet header through which the fluid in the two-phase gas-liquid state flows has an inner diameter that is smaller than the inner diameter of the other headers. Thus, the gas and the liquid are made uniform by mixing of the gas and the liquid within a pipe due to an increase in gas flow velocity, so that the low-temperature fluid is distributed to the through-holes with a uniform gas-to-liquid ratio, thereby maximizing the temperature efficiency of the fluid and achieving high heat exchanging performance (for example, see Patent Literature 1).
CITATION LIST Patent LiteraturePatent Literature 1: Japanese Unexamined Patent Application Publication No. 2008-101852 (paragraph [0036], FIG. 1)
SUMMARY OF INVENTION Technical ProblemA refrigeration and air-conditioning apparatus that uses the aforementioned heat exchanger in the related art has a refrigerant circuit in which a compressor, a radiator, flow control means, and an evaporator are connected by a refrigerant pipe, and a refrigerant, such as an HFC (hydrofluorocarbon) based refrigerant, hydrocarbon, or carbon dioxide, circulates through this refrigerant circuit. In order to increase the efficiency of the refrigeration and air-conditioning apparatus, it is important to increase the heat exchanging performance of the heat exchanger.
However, in the aforementioned heat exchanger in the related art, when the refrigerant in the two-phase gas-liquid state flows through the inlet header in a low flow-rate range, the mixing of the gas and the liquid is insufficient, causing the gas and the liquid to flow separately from each other. Thus, the ratio of the gas and the liquid distributed to the through-holes in the passage section becomes non-uniform. This results in an excess or insufficient amount of fluid that can effectively exchange heat in each of the through-holes in the passage section. Therefore, in the aforementioned heat exchanger in the related art, there is a problem in that the temperature efficiency significantly decreases, causing the heat exchanging performance to deteriorate. There is another problem in that the heat exchanger needs to be increased in size more than necessary to compensate for the deterioration in the heat exchanging performance. On the other hand, if the header diameter is reduced too much in accordance with the low flow-rate range, when the refrigerant in the two-phase gas-liquid state flows through the inlet header in a high flow-rate range, a pressure loss increases, which is a problem in that it leads to an increase in power used by a driving device that transports the fluid to the heat exchanger. Accordingly, with the aforementioned heat exchanger in the related art, it is difficult to make the heat exchanger operate efficiently while achieving uniform gas-liquid distribution over a wide operating range.
The present invention has been made to solve the aforementioned problems, and an object thereof is to obtain a compact, high-performance heat exchanger and a compact, high-performance refrigeration and air-conditioning apparatus.
Solution to ProblemA heat exchanger according to the present invention includes a first passage section having a plurality of through-holes through which a high-temperature fluid flows; a second passage section having a plurality of through-holes through which a low-temperature fluid flows; a first inlet header having a tubular shape and connected to one end of the first passage section; a first outlet header having a tubular shape and connected to other end of the first passage section; a second inlet header having a tubular shape and connected to one end of the second passage section; and a second outlet header having a tubular shape and connected to other end of the second passage section. The first passage section and the second passage section are disposed in a heat exchangeable manner via a partition wall provided therebetween. At least one of the high-temperature fluid flowing into the through-holes in the first passage section from the first inlet header and the low-temperature fluid flowing into the through-holes in the second passage section from the second inlet header is a fluid in a two-phase gas-liquid state. A direction in which the fluid in the two-phase gas-liquid state flows into the passage section from the inlet header is a substantially horizontal direction or an upward direction relative to the substantially horizontal direction.
A refrigeration and air-conditioning apparatus according to the present invention is equipped with the heat exchanger according to the present invention.
Advantageous Effects of InventionAccording to the present invention, a compact, high-performance heat exchanger can be provided. Furthermore, according to the present invention, a compact, high-performance refrigeration and air-conditioning apparatus can be provided.
In Embodiment 1, a substantially-horizontal inflow segment 2a is provided at an end of each second flat pipe 2 shown in
First flat pipes 1 each have a plurality of through-holes extending in the longitudinal direction (i.e., the left-right direction in
One longitudinal end of each first flat pipe 1 is connected to a side surface of a first inlet header 3 having a tubular shape, while the other end is connected to a side surface of a first outlet header 4 having a tubular shape. In other words, the through-holes formed in the first flat pipes 1 form parallel passages through which the high-temperature fluid flows. The inflow segment 2a serving as one longitudinal end of each second flat pipe 2 is connected to a side surface of the second inlet header 5 having a tubular shape. An outflow segment 2d serving as the other longitudinal end of each second flat pipe 2 is connected to a side surface of a second outlet header 6 having a tubular shape. The inflow segment 2a and the outflow segment 2d are connected to the heat exchanging segment 2c via bent segments 2b. In other words, the through-holes 21 formed in the second flat pipes 2 form parallel passages through which the low-temperature fluid flows.
The first inlet header 3, the first outlet header 4, the second inlet header 5, and the second outlet header 6 are disposed such that axial directions thereof are parallel to the flat surfaces of the flat pipes 1 and 2 (specifically, the parallel-arranged direction of the through-holes formed in the flat pipes 1 and 2).
Furthermore, the inflow segments 2a of the second flat pipes 2, through which the low-temperature fluid in the two-phase gas-liquid state flows, connected to the second inlet header 5 are substantially horizontal. Specifically, the passages (in other words, the through-holes 21 in the inflow segments 2a) for the low-temperature fluid in the two-phase gas-liquid state flowing into the second flat pipes 2 from the second inlet header 5 are substantially horizontal.
The first flat pipes 1 correspond to “first passage section” according to the present invention, and the second flat pipes 2 correspond to “second passage section” according to the present invention.
The high-temperature fluid flows through the first inlet header 3, the first flat pipes 1, and the first outlet header 4 in that order, the low-temperature fluid flows through the second inlet header 5, the second flat pipes 2, and the second outlet header 6 in that order, and the two fluids exchange heat via contact sections between the first flat pipes 1 and the second flat pipes 2 (more specifically, the heat exchanging segments 2c). In other words, the high-temperature fluid flowing through the through-holes in the first flat pipes 1 and the low-temperature fluid flowing through the through-holes in the second flat pipes 2 exchange heat via outer hulls, serving as partition walls between the through-holes, of the first flat pipes 1 and the second flat pipes 2.
Although the heat exchanger 10 is constituted of several first flat pipes 1 and several second flat pipes 2 in Embodiment 1, the number of flat pipes 1 and the number of flat pipes 2 are not limited to the numbers in Embodiment 1. The parallel passages may be formed by alternately arranging one first flat pipe 1 and one second flat pipe 2 along a flat plane. Furthermore, although the first flat pipes 1 and the second flat pipes 2 in Embodiment 1 are disposed in contact with each other such that the flowing directions of the fluids flowing therethrough are parallel to each other, the flat pipes may alternatively be disposed in contact with each other such that the flowing directions are orthogonal to each other. As a further alternative, the first flat pipes 1 and the second flat pipes 2 may be stacked while folding the first flat pipes 1 and the second flat pipes 2. Furthermore, although the end of the inflow segment 2a of each second flat pipe 2 is substantially aligned with the inner surface of the second inlet header 5 in
In the heat exchanger 10 according to Embodiment 1, the ends of the second flat pipes 2, through which the two-phase gas-liquid fluid flows, connected to the second inlet header 5 are substantially horizontal. In other words, the outflowing direction of the two-phase gas-liquid fluid flowing out from the second inlet header 5 toward the through-holes 21 (in other words, the inflowing direction of the two-phase gas-liquid fluid flowing into the through-holes 21) is substantially horizontal. More specifically, in Embodiment 1, even when the refrigerant flow velocity within the second inlet header 5 decreases to cause the gas and the liquid to flow separately through the upper side and the lower side therein, the liquid accumulates from the bottom of the second inlet header 5 to near the inflow segments of the second flat pipes 2 so that a gas-liquid interface is formed exactly near the inflow segments of the second flat pipes 2, whereby favorable gas-liquid distribution is achieved. In other words, for example, if the refrigerant flows vertically downward from the horizontally-disposed second inlet header 5 toward the second flat pipes 2, the gas-liquid distribution would deteriorate since the liquid alone tends to selectively flow out toward the second flat pipes 2 located at the upstream side before a liquid surface is formed within the second inlet header 5. In contrast, this does not occur in the heat exchanger 10 according to Embodiment 1 because the ends of the second flat pipes 2 connected to the second inlet header 5 are substantially horizontal. Therefore, the low-temperature fluid can be distributed to the through-holes 21 in the second flat pipes 2 with a uniform gas-to-liquid ratio so that the temperature efficiency of the fluid can be maximized and the pressure loss can be minimized, thereby allowing for improved heat exchanging performance of the heat exchanger 10. Consequently, with the heat exchanger 10 according to Embodiment 1, a compact, high-performance heat exchanger can be obtained.
With regard to the ends of the flat pipes connected to the remaining headers 3, 4, and 6, the ends do not particularly need to be horizontal unless a two-phase gas-liquid fluid flows therethrough.
Furthermore, although the inflow segments 2a are formed by bending the second flat pipes 2 outside the second inlet header 5 in Embodiment 1, the inflow segments 2a may alternatively be formed by bending the second flat pipes 2 inside the second inlet header 5 to an extent that the gas-liquid flow within the second inlet header 5 is not disturbed, as shown in
In the heat exchanger 10 according to Embodiment 1, the inflow segments 2a of the second flat pipes 2 connected to the second inlet header 5 are maintained in a substantially horizontal state even if the heat exchanger 10 is positionally inverted. Therefore, the gas-liquid distribution does not deteriorate. Consequently, the heat exchanger 10 according to Embodiment 1 is advantageous in that the degree of freedom in terms of installation and the degree of freedom in terms of connection and routing of pipes are increased.
Generally, the distribution characteristics of the two-phase gas-liquid fluid toward the through-holes in the flat pipes change significantly depending on the outflowing direction of the fluid flowing out from the header toward the through-holes (in other words, the inflowing direction of the fluid flowing into the through-holes). Therefore, an effect that this direction has on the heat transfer characteristics (i.e., the distribution characteristics of the two-phase gas-liquid fluid) in the heat exchanger 10 is examined by performing tests (
In this case, Mh denotes a mass flow rate (kg/h) of the high-temperature fluid, Cph denotes isobaric specific heat (J/kgK) of the high-temperature fluid, Thi denotes an inlet temperature of the high-temperature fluid, Tho denotes an outlet temperature of the high-temperature fluid, Tco denotes an outlet temperature of the low-temperature fluid, and Tci denotes an inlet temperature of the low-temperature fluid.
In the tests shown in
The second inlet header 5 has an inner diameter D of 6 mm. The through-holes formed in the first flat pipes 1 are rectangular holes with about 1 mm sides, and a total of 60 through-holes are formed in each first flat pipe 1. Furthermore, these through-holes are arranged in the width direction of the first flat pipe 1. The through-holes 21 formed in the second flat pipes 2 are also rectangular holes with about 1 mm sides, and a total of 60 through-holes 21 are formed in each second flat pipe 2. Furthermore, these through-holes 21 are arranged in the width direction of the second flat pipe 2.
The protruding length of the ends of each first flat pipe 1 from the inner surfaces of the headers is 2 mm.
In the tests shown in
The mass flow rate Mh of the high-temperature fluid is 600 kg/h. A mass flow rate Mc of the low-temperature fluid ranges between 80 kg/h and 100 kg/h. A ratio of the mass flow rate of the gas to the overall mass flow rate of the gas and the liquid in the low-temperature fluid (i.e., quality X) is adjusted between 0.1 and 0.2. This range of the quality X is a generally used range for the inlet quality in the heat exchanger 10 used in a common refrigeration and air-conditioning apparatus.
The triangles, squares, and circles shown in
In
Unlike the heat exchanger 10 shown in
As shown in
Unlike the heat exchanger 10 shown in
As shown in
Unlike the heat exchanger 10 shown in
When the position angle β=0°, the low-temperature fluid (in the two-phase gas-liquid state) flows out toward the through-holes 21 in the second flat pipes 2 in the horizontal direction, and the low-temperature fluid (in the two-phase gas-liquid state) flows into the second inlet header 5 in the vertically downward direction. When 0°<position angle β<90°, the low-temperature fluid (in the two-phase gas-liquid state) flows out toward the through-holes 21 in the second flat pipes 2 upward relative to the horizontal direction, and the low-temperature fluid (in the two-phase gas-liquid state) flows into the second inlet header 5 downward relative to the horizontal direction. When the position angle β=90°, the low-temperature fluid (in the two-phase gas-liquid state) flows out toward the through-holes 21 in the second flat pipes 2 in the vertically upward direction, and the low-temperature fluid (in the two-phase gas-liquid state) flows into the second inlet header 5 in the horizontal direction. When 90°<position angle β<180°, the low-temperature fluid (in the two-phase gas-liquid state) flows out toward the through-holes 21 in the second flat pipes 2 upward relative to the horizontal direction, and the low-temperature fluid (in the two-phase gas-liquid state) flows into the second inlet header 5 upward relative to the horizontal direction. When the position angle β=180°, the low-temperature fluid (in the two-phase gas-liquid state) flows out toward the through-holes 21 in the second flat pipes 2 in the horizontal direction, and the low-temperature fluid (in the two-phase gas-liquid state) flows into the second inlet header 5 in the vertically upward direction.
When −90°<position angle β<0°, the low-temperature fluid (in the two-phase gas-liquid state) flows out toward the through-holes 21 in the second flat pipes 2 downward relative to the horizontal direction, and the low-temperature fluid (in the two-phase gas-liquid state) flows into the second inlet header 5 downward relative to the horizontal direction. When the position angle β=−90°, the low-temperature fluid (in the two-phase gas-liquid state) flows out toward the through-holes 21 in the second flat pipes 2 in the vertically downward direction, and the low-temperature fluid (in the two-phase gas-liquid state) flows into the second inlet header 5 in the horizontal direction. When −180°<position angle β<−90°, the low-temperature fluid (in the two-phase gas-liquid state) flows out toward the through-holes 21 in the second flat pipes 2 downward relative to the horizontal direction, and the low-temperature fluid (in the two-phase gas-liquid state) flows into the second inlet header 5 downward relative to the horizontal direction. When the position angle β=−180°, the low-temperature fluid (in the two-phase gas-liquid state) flows out toward the through-holes 21 in the second flat pipes 2 in the horizontal direction, and the low-temperature fluid (in the two-phase gas-liquid state) flows into the second inlet header 5 in the vertically downward direction.
As shown in
Accordingly, in the heat exchanger 10 according to Embodiment 1, at least one of the high-temperature fluid flowing into the through-holes in the first flat pipes 1 from the first inlet header 3 and the low-temperature fluid flowing into the through-holes 21 in the second flat pipes 2 from the second inlet header 4 is a fluid in a two-phase gas-liquid state. The two-phase gas-liquid fluid flows into the flat pipes from the inlet header in a substantially horizontal direction or in an upward direction relative to the substantially horizontal direction. Therefore, even when the flow velocity within the second inlet header 5 decreases to cause the gas and the liquid to flow separately through the upper side and the lower side therein, the inflow segments extending from the second inlet header 5 to the second flat pipes 2 are prevented from being constantly filled with the liquid, thereby preventing deterioration in the gas-liquid distribution caused by the liquid alone flowing out selectively to the second flat pipes 2 located at the upstream side. Therefore, the two-phase gas-liquid fluid can be distributed to the through-holes with a uniform gas-to-liquid ratio so that the temperature efficiency of the fluid can be maximized and the pressure loss can be minimized. In other words, the heat exchanging performance of the heat exchanger 10 can be improved.
Consequently, with the heat exchanger 10 according to Embodiment 1, a compact, high-performance heat exchanger can be obtained.
The description of Embodiment 1 is directed to a case where the low-temperature fluid flowing through the second inlet header 5 turns into a two-phase gas-liquid state. If the high-temperature fluid flowing through the first inlet header 3 turns into a two-phase gas-liquid state, similar advantages can be achieved by making the high-temperature fluid flow into the through-holes in the first flat pipes 1 from the first inlet header 3 in a substantially horizontal direction.
Embodiment 2The configuration of the heat exchanger 10 according to Embodiment 1 is merely an example; for example, the heat exchanger 10 may be configured as follows. The following description will mainly be focused on the differences from the heat exchanger 10 according to Embodiment 1.
In a heat exchanger 10 shown in
In addition to achieving the advantages of Embodiment 1, the heat exchanger 10 having such a configuration achieves compactness since the height of the flat pipes 1 and 2 is reduced in the stacked direction thereof.
In each of the second flat pipes 2 in a heat exchanger 10 shown in
In addition to achieving the advantages of Embodiment 1, the heat exchanger 10 having such a configuration is advantageous in that the installation space can be made compact in the height direction when a plurality of heat exchangers 10 are installed. In other words, when a plurality of heat exchangers 10 are installed by stacking them in the stacked direction of the flat pipes 1 and 2 for increasing the heat exchanging capability, gaps between the heat exchangers 10 in the height direction can be reduced while interference between the headers 3, 4, 5, and 6 is prevented.
In a heat exchanger 10 shown in
Second flat pipes 2B disposed below the first flat pipes 1 each have an inflow segment 2Ba, a heat exchanging segment 2Bc, an outflow segment 2Bd, and bent segments 2Bb. The inflow segment 2Ba is connected to a second inlet header 5B and has a substantially horizontal passage. The outflow segment 2Bd is connected to a second outlet header 6B and has a substantially horizontal passage. The heat exchanging segment 2Bc and the corresponding first flat pipe 1 are stacked such that flat surfaces thereof are in contact with each other. The bent segments 2Bb connect between the inflow segment 2Ba and the heat exchanging segment 2Bc, as well as between the heat exchanging segment 2Bc and the outflow segment 2Bd. The ends of each second flat pipe 2B are bent so as to extend under the first inlet header 3 and the first outlet header 4.
When increasing the heat exchanging capability, optimizing the heat transfer and flow characteristics of the second flat pipes 2 or the like, there is a case where two second flat pipes 2A and 2B are disposed for each first flat pipe 1. In the heat exchanger 10 having such a configuration, the low-temperature fluid in the two-phase gas-liquid state is made to flow out toward the through-holes 21 in the second flat pipes 2A in a substantially horizontal direction. Furthermore, in the heat exchanger 10 having such a configuration, the low-temperature fluid in the two-phase gas-liquid state is made to flow out toward the through-holes 21 in the second flat pipes 2B in a substantially horizontal direction. Therefore, similar to Embodiment 1, the gas-to-liquid ratio of the low-temperature fluid distributed to the through-holes 21 can be made uniform, whereby a compact, high-performance heat exchanger 10 can be obtained.
Embodiment 3The heat exchanger 10 according to each of Embodiment 1 and Embodiment 2 is installed in, for example, a refrigeration and air-conditioning apparatus, such as an air-conditioning apparatus, a hot-water storage apparatus, or a refrigeration apparatus. An example of a refrigeration and air-conditioning apparatus equipped with the heat exchanger 10 according to Embodiment 1 or Embodiment 2 will be described below.
The refrigeration and air-conditioning apparatus shown in
The refrigeration and air-conditioning apparatus also has a second refrigerant circuit in which the heat exchanger 10, a second compressor 40, a second radiator 41, and a second pressure reducing device 42 are connected in that order with pipes. The second outlet header 6 of the heat exchanger 10 is connected to the second compressor 40, and the second inlet header 5 is connected to the second pressure reducing device 42. The second refrigerant circuit makes a second refrigerant serving as a low-temperature fluid circulate therethrough and operates based on a vapor compression refrigeration cycle. The first refrigerant and the second refrigerant used are a refrigerant such as carbon dioxide, an HFC-based refrigerant, an HC-based refrigerant, an HFO-based refrigerant, and ammonia. In Embodiment 3, carbon dioxide is used as the first refrigerant.
The first refrigerant is compressed by the first compressor 30 and is discharged therefrom as a high-temperature high-pressure supercritical fluid. The first refrigerant having become a high-temperature high-pressure supercritical fluid is transported to the first radiator 31 and is decreased in temperature by exchanging heat with air or the like at the first radiator 31, thereby becoming a high-pressure supercritical fluid. The first refrigerant having become a high-pressure supercritical fluid is decreased in temperature by being cooled by the heat exchanger 10, flows into the first pressure reducing device 32 where the first refrigerant is decompressed so as to change into a low-temperature low-pressure two-phase gas-liquid state, and is then transported to the first cooling unit 33. The first refrigerant in the low-temperature low-pressure two-phase gas-liquid state evaporates by exchanging heat with air or the like at the first cooling unit 33 and then returns to the first compressor 30.
On the other hand, the second refrigerant is compressed by the second compressor 40 and is discharged therefrom as high-temperature high-pressure vapor. The second refrigerant having becoming high-temperature high-pressure vapor is transported to the second radiator 41 and is decreased in temperature by exchanging heat with air or the like at the second radiator 41, thereby becoming a high-pressure liquid. The second refrigerant having become a high-pressure liquid is decompressed by the second pressure reducing device 42 so as to change into a low-temperature two-phase gas-liquid state, and is transported to the heat exchanger 10. The second refrigerant in the low-temperature two-phase gas-liquid state becomes vapor by being heated at the heat exchanger 10 and then returns to the second compressor 40.
In the refrigeration and air-conditioning apparatus having such a configuration, a large degree of subcooling for the refrigerant flowing out from the first radiator 31 can be ensured so that the efficiency of the refrigeration and air-conditioning apparatus can be significantly improved.
Even if an HFC-based refrigerant, an HC-based refrigerant, an HFO-based refrigerant, or ammonia is used as the first refrigerant flowing through the first refrigerant circuit, the efficiency of the refrigeration and air-conditioning apparatus is improved by ensuring a large degree of subcooling for the refrigerant flowing out from the first radiator 31. The efficiency of the refrigeration and air-conditioning apparatus is improved especially when the first refrigerant in the first refrigerant circuit is carbon dioxide and transfers heat at a critical point or higher.
Although the second refrigerant circuit is described as being a vapor compression refrigeration cycle in Embodiment 3, the second refrigerant may alternatively be water or brine (antifreeze), such as an ethylene glycol aqueous solution, and the second compressor 40 may alternatively be a pump.
In the refrigeration and air-conditioning apparatus shown in
The refrigeration and air-conditioning apparatus shown in
A refrigerant (i.e., low-temperature fluid) decompressed by the bypass pressure reducing device 51 changes into a low-temperature two-phase gas-liquid state, exchanges heat at the heat exchanger 10 with a refrigerant (i.e., high-temperature fluid) flowing out from the first radiator 31, and is then transported to the injection port 53 of the first compressor 30. A refrigerant such as an HFC-based refrigerant, an HC-based refrigerant, an HFO-based refrigerant, ammonia, and carbon dioxide is used in the refrigeration and air-conditioning apparatus shown in
In the refrigeration and air-conditioning apparatus having such a configuration, a large degree of subcooling for the refrigerant flowing out from the first radiator 31 can be ensured so that the efficiency of the refrigeration and air-conditioning apparatus can be significantly improved.
Furthermore, in the refrigeration and air-conditioning apparatus shown in
If the second end of the bypass pipe 52 is connected between the first compressor 30 and the first cooling unit 33, the flow rate of refrigerant flowing through the first cooling unit 33 can be reduced without reducing the refrigeration effect, as compared with a case where the heat exchanger 10 is not used. This is effective especially if the pipe length between the first compressor 30 and the first cooling unit 33 is large since deterioration in performance caused by an increase in pressure loss can be suppressed.
Accordingly, with the compact, high-performance heat exchanger 10 installed, a refrigeration and air-conditioning apparatus that is compact and has the above-described advantages can be obtained.
Embodiment 4In the heat exchanger 10 described in each of Embodiment 1 and Embodiment 2, the first flat pipes 1 through which the high-temperature fluid flows and the second flat pipes 2 through which the low-temperature fluid flows are formed independently of each other, and the first flat pipes 1 and the second flat pipes 2 are stacked such that the flat surfaces thereof are joined together by soldering or the like. In other words, in the heat exchanger 10 described in each of Embodiment 1 and Embodiment 2, the refrigerant passages through which the high-temperature fluid flows and the refrigerant passages through which the low-temperature fluid flows are formed in separate components. Alternatively, in the heat exchanger 10, the refrigerant passages through which the high-temperature fluid flows and the refrigerant passages through which the low-temperature fluid flows may be formed in the same component (in other words, the first passage section and the second passage section according to the present invention may be integrally formed). The heat exchanger 10 having such a configuration may be installed in the refrigeration and air-conditioning apparatus according to Embodiment 3. In Embodiment 4, items not described in particular are the same as those in Embodiment 1 to Embodiment 3.
As shown in
The expression “aligned” used here does not imply that the parallel-arranged direction of the first refrigerant passages 101a is exactly parallel to the parallel-arranged direction of the second refrigerant passages 102a, but indicates that the parallel-arranged directions of the two are substantially aligned with each other. Therefore, the expression “the parallel-arranged directions of the two are aligned with each other” will be used in Embodiment 4 even if the parallel-arranged direction of the first refrigerant passages 101a and the parallel-arranged direction of the second refrigerant passages 102a are somewhat tilted.
In other words, in Embodiment 4, the first refrigerant path 101 and the second refrigerant path 102 are integrally formed. The main body 110 having the first refrigerant path 101 and the second refrigerant path 102 is composed of, for example, aluminum or an aluminum alloy, copper or a copper alloy, steel, or a stainless alloy, and is manufactured by extrusion, pultrusion or the like.
One of two ends of the main body 110 in the refrigerant flowing direction is provided with a second inlet communication hole 105a that extends in the parallel-arranged direction of the second refrigerant passages 102a and communicates with all of the second refrigerant passages 102a. The other end is provided with a second outlet communication hole 106a that extends in the parallel-arranged direction of the second refrigerant passages 102a and communicates with all of the second refrigerant passages 102a. In other words, in the heat exchanger 10 shown in
Similarly, of the two ends of the main body 110 in the refrigerant flowing direction, the one end that is provided with the second outlet communication hole 106a is provided with a first inlet communication hole 103a that extends in the parallel-arranged direction of the first refrigerant passages 101a and communicates with all of the first refrigerant passages 101a. Moreover, of the two ends of the main body 110 in the refrigerant flowing direction, the other end that is provided with the second inlet communication hole 105a is provided with a first outlet communication hole 104a that extends in the parallel-arranged direction of the first refrigerant passages 101a and communicates with all of the first refrigerant passages 101a. In other words, in the heat exchanger 10 shown in
Furthermore, the first inlet communication hole 103a and the second outlet communication hole 106a are slightly displaced relative to each other in the refrigerant flowing direction of the first refrigerant passages 101a (in other words, the second refrigerant passages 102a). Moreover, the first outlet communication hole 104a and the second inlet communication hole 105a are slightly displaced relative to each other in the refrigerant flowing direction of the first refrigerant passages 101a (in other words, the second refrigerant passages 102a).
The extending direction of the first inlet communication hole 103a and the first outlet communication hole 104a do not necessarily need to be orthogonal to the direction of the first refrigerant passages 101a. Furthermore, the extending direction of the second inlet communication hole 105a and the second outlet communication hole 106a do not necessarily need to be orthogonal to the direction of the second refrigerant passages 102a.
The first inlet communication hole 103a, the first outlet communication hole 104a, the second inlet communication hole 105a, and the second outlet communication hole 106a each have one open end and are respectively connected to a first inlet connection pipe 103, a first outlet connection pipe 104, a second inlet connection pipe 105, and a second outlet connection pipe 106 so as to communicate with the outside. The other end of each of the first inlet communication hole 103a, the first outlet communication hole 104a, the second inlet communication hole 105a, and the second outlet communication hole 106a is closed by a sealing member or the like.
In
Both ends of each of the plurality of first refrigerant passages 101a and second refrigerant passages 102a extending through the main body 110 in the longitudinal direction are sealed by a process such as pinching or sealed by using sealing members (not shown).
The heat exchanger 10 according to Embodiment 4 is assumed to be used in a position that makes the low-temperature fluid and the high-temperature fluid flow in the up-down direction as shown in
Specifically, when the second inlet communication hole 105a is observed in the central-axis direction of the second inlet communication hole 105a, the central axis of the second inlet communication hole 105a is disposed at a position that is aligned with a connection section between the second inlet communication hole 105a and the second refrigerant path 102 (i.e., the second refrigerant passages 102a), or at a position away from the first refrigerant path 101 (i.e., the first refrigerant passages 101a) relative to the connection section.
Thus, in the heat exchanger 10 according to Embodiment 4, the second refrigerant path 102 and the second inlet header 5 are connected with a position angle α in a range of 0°≦α<110° (or −110°<α≦0 if the positive direction is the same as in
The first refrigerant path 101, the second refrigerant path 102, the first inlet communication hole 103a, the first outlet communication hole 104a, the second inlet communication hole 105a, and the second outlet communication hole 106a respectively correspond to “first passage section”, “second passage section”, “first inlet header”, “first outlet header”, “second inlet header”, and “second outlet header” according to the present invention.
Next, a heat exchanging process between the high-temperature fluid and the low-temperature fluid in the heat exchanger 10 according to Embodiment 4 will be described with reference to
The high-temperature fluid flows into the first inlet communication hole 103a via the first inlet connection pipe 103, flows through the first refrigerant path 101 and the first outlet communication hole 104a in that order, and then flows out from the first outlet connection pipe 104. On the other hand, the low-temperature fluid in a two-phase gas-liquid state flows into the second inlet communication hole 105a via the second inlet connection pipe 105, flows through the second refrigerant path 102 and the second outlet communication hole 106a in that order, and then flows out from the second outlet connection pipe 106. During this time, the high-temperature fluid flowing through the first refrigerant path 101 and the low-temperature fluid flowing through the second refrigerant path 102 exchange heat in a countercurrent manner via a partition wall between the refrigerant paths.
In the heat exchanger 10 having the configuration as in Embodiment 4, when the second inlet communication hole 105a is observed in the central-axis direction of the second inlet communication hole 105a, the central axis of the second inlet communication hole 105a is disposed at a position that is aligned with the connection section between the second inlet communication hole 105a and the second refrigerant path 102 (i.e., the second refrigerant passages 102a), or at a position away from the first refrigerant path 101 (i.e., the first refrigerant passages 101a) relative to the connection section. Consequently, the position angle α when the low-temperature fluid in the two-phase gas-liquid state flows into the second refrigerant path 102 from the second inlet communication hole 105a is in a range of 0°≦α<110°. Therefore, the low-temperature fluid in the two-phase gas-liquid state is readily distributed to the second refrigerant passages 102a of the second refrigerant path 102 with a substantially uniform gas-to-liquid ratio, whereby a heat exchanger 10 with stable performance can be obtained.
It is apparent from Embodiment 1 that, if the direction indicated by an arrow in
With the first refrigerant path 101 and the second refrigerant path 102 formed integrally in the main body 110, the following various advantages can also be achieved.
First, heat resistance generated, in case that the passages through which the high-temperature fluid flows and the passages through which the low-temperature fluid flows are formed in separate components, at joint surfaces of these components is suppressed, whereby the heat exchanging performance of the heat exchanger 10 can be improved.
Furthermore, because the first inlet communication hole 103a and the first outlet communication hole 104a are provided inside the main body 110 of the heat exchanger 10, an additional header pipe for connecting to the first refrigerant path 101 is not necessary, thereby achieving compactness of the heat exchanger 10, as well as simplifying the manufacturing process. The same applies to the second inlet communication hole 105a and the second outlet communication hole 106a with respect to the second refrigerant path 102.
Furthermore, since the first inlet communication hole 103a and the second outlet communication hole 106a are slightly displaced relative to each other in the fluid flowing direction, and the first outlet communication hole 104a and the second inlet communication hole 105a are slightly displaced relative to each other in the fluid flowing direction, the distance between the first refrigerant path 101 and the second refrigerant path 102 located next to each other can be shortened, as compared with a case where the holes are not displaced, thereby achieving compactness of the heat exchanger 10.
In the heat exchanger 10 according to Embodiment 4, although the first refrigerant passages 101a and the second refrigerant passages 102a are rectangular in cross section, as shown in
Although the number of first refrigerant passages 101a in the first refrigerant path 101 and the number of second refrigerant passages 102a in the second refrigerant path 102 are the same in the heat exchanger 10 according to Embodiment 4, as shown in
Although the high-temperature fluid flowing through the first refrigerant path 101 and the low-temperature fluid flowing through the second refrigerant path 102 exchange heat in a countercurrent manner, the two fluids may alternatively exchange heat in a parallel current manner. For example, by making the high-temperature fluid flow in from the first inlet connection pipe 103 and making the low-temperature fluid flow in from the second outlet connection pipe 106, the high-temperature fluid and the low-temperature fluid are made to flow in parallel to each other.
Furthermore, although the heat exchanger 10 in
The heat exchanger 10 shown in
In the heat exchanger 10 having the configuration shown in
As shown in
1 first flat pipe, 1a inflow segment, 1b bent segment, 1c heat exchanging segment, 1d outflow segment, 2 second flat pipe, 2a inflow segment, 2b bent segment, 2c heat exchanging segment, 2d outflow segment, 2A second flat pipe, 2Aa inflow segment, 2Ab bent segment, 2Ac heat exchanging segment, 2Ad outflow segment, 2B second flat pipe, 2Ba inflow segment, 2Bb bent segment, 2Bc heat exchanging segment, 2Bd outflow segment, 3 first inlet header, 4 first outlet header, 5 second inlet header, 5A second inlet header, 5B second inlet header, 6 second outlet header, 6A second outlet header, 6B second outlet header, 10 heat exchanger, 21 through-hole, 30 first compressor, 31 first radiator, 32 first pressure reducing device, 33 first cooling unit, 40 second compressor, 41 second radiator, 42 second pressure reducing device, 52 bypass pipe, 53 injection port, 101 first refrigerant path, 101a first refrigerant passage, 102 second refrigerant path, 102a second refrigerant passage, 103 first inlet connection pipe, 103a first inlet communication hole, 104 first outlet connection pipe, 104a first outlet communication hole, 105 second inlet connection pipe, 105a second inlet communication hole, 106 second outlet connection pipe, 106a second outlet communication hole, 110 main body.
Claims
1-9. (canceled)
10. A heat exchanger comprising:
- a main body in which a plurality of through-holes are arranged in parallel to each other as a first passage section and a plurality of through-holes aligned with the first passage section are arranged in parallel to each other as a second passage section, the main body being integrally formed with the first passage section and the second passage section, wherein
- the main body is formed with a second inlet header as a hole that communicates with the plurality of through-holes of the second passage section,
- the second inlet header is formed to shift a position away from the through-holes aligned with the first passage section relative to a connection position between the second inlet header and the plurality of through-holes of the second passage section.
11. A refrigeration and air-conditioning apparatus comprising the heat exchanger of claim 10.
12. The heat exchanger of claim 10, wherein
- the second inlet header has a central axis, and
- in case of observing in a direction of the central axis, the central axis is disposed at the position away from the through-holes aligned with the first passage section relative to the connection position between the second inlet header and the through-holes of the second passage section.
13. The heat exchanger of claim 10, wherein
- the main body includes a first inlet header and a first outlet header as holes that communicate with the plurality of through-holes of the first passage section, and
- the main body includes a second outlet header as a hole that communicates with the plurality of through-holes of the second passage section.
14. The heat exchanger of claim 13, wherein
- a hole of the first inlet header, a hole of the second inlet header, a hole of the first outlet header, and a hole of the second outlet header are each a shifted position in an extending direction of through-holes of the first passage section or the second passage section.
15. A method for heat exchange that uses the heat exchanger of claim 10, comprising:
- flowing a two-phase gas-liquid fluid into the second passage section, the two-phase gas-liquid fluid being lower temperature than a fluid flowed into the first passage section.
16. The method for heat exchange of claim 15, wherein
- an extending direction of the plurality of through-holes of the second passage section is set to a vertical direction, and
- a direction for the second inlet header to communicate is set to a horizontal direction.
17. The method for heat exchange of claim 16, further comprising:
- flowing the fluid into the second passage section upward from the second inlet header.
18. The method for heat exchange of claim 15, wherein
- an extending direction of the plurality of through-holes of the second passage section is set horizontally, and
- in case of observing in a central-axis direction of the second inlet header, a direction from a position of a central-axis of the hole of the second inlet header to a connection position between the second inlet header and the through-holes of the first passage section is set upward relative to a horizontal direction.
Type: Application
Filed: Aug 5, 2011
Publication Date: May 23, 2013
Applicant: Mitsubishi Electric Corporation (Chiyoda-ku,Tokyo)
Inventors: Susumu Yoshimura (Chiyoda-ku), Hiroaki Nakamune (Chiyoda-ku), Mizuo Sakai (Chiyoda-ku), Soshi Ikeda (Chiyoda-ku)
Application Number: 13/813,675
International Classification: F28D 1/02 (20060101); F28D 15/00 (20060101);