JP2012202609A - Water heat exchanger - Google Patents

Abstract

An object of the present invention is to improve the corrosion resistance of a water pipe in a water heat exchanger having a three-layer pipe structure of a flat pipe and exchanging heat between refrigerant and water.
A water heat exchanger (22) has a pair of refrigerant pipes (41) and a water pipe (42), and both sides of the side surface on the long side of the cross section of the water pipe (42) are a pair. The refrigerant flowing through the pair of refrigerant pipes (41) exchanges heat with the water inside the water pipe (42) by being sandwiched and adhered to one side of the long side of the cross section of the refrigerant pipe (41). The three-layer pipe (43) for heating the water inside the water pipe (42) is configured. Here, the water pipe (42) is made of stainless steel.
[Selection] Figure 3

Description

  The present invention relates to a water heat exchanger, and more particularly, to a water heat exchanger having a three-layer tube structure with flat tubes and exchanging heat between refrigerant and water.

  2. Description of the Related Art Conventionally, there is a water heat exchanger that exchanges heat between a refrigerant and water as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2010-190564). This water heat exchanger has a pair of refrigerant pipes and a water pipe. The pair of refrigerant tubes is constituted by a multi-hole flat tube having a plurality of refrigerant flow channel holes. The water pipe is constituted by a small flat tube having a smaller number of water flow path holes than the number of refrigerant flow path holes of the refrigerant pipe. Then, both surfaces of the side surface on the long side of the cross section of the water pipe are sandwiched and closely adhered to one side surface of the long side of the cross section of the pair of refrigerant tubes, so that the refrigerant circulating in the pair of refrigerant tubes A three-layer pipe that heats the water inside the water pipe by exchanging heat with the water inside is formed.

  Since the conventional water heat exchanger has a three-layer tube structure of flat tubes (that is, a pair of refrigerant tubes and water tubes), there is an advantage that heat can be efficiently exchanged between water and the refrigerant. is there.

  However, since the water pipe is easily corroded by water depending on the material, it is necessary to improve the corrosion resistance.

  An object of the present invention is to improve the corrosion resistance of a water pipe in a water heat exchanger having a three-layer pipe structure with a flat pipe and exchanging heat between refrigerant and water.

  A water heat exchanger according to a first aspect is a water heat exchanger that exchanges heat between a refrigerant and water, and includes a pair of refrigerant tubes and a water tube. The pair of refrigerant tubes is configured by a multi-hole flat tube having a plurality of refrigerant channel holes, and the refrigerant flows through the plurality of refrigerant channel holes. The water pipe is constituted by a small flat tube having a smaller number of water flow path holes than the number of the refrigerant flow path holes of the refrigerant pipe, and water flows through the water flow path holes. Then, both surfaces of the side surface on the long side of the cross section of the water pipe are sandwiched and closely adhered to one side surface of the long side of the cross section of the pair of refrigerant tubes, so that the refrigerant circulating in the pair of refrigerant tubes A three-layer pipe that heats the water inside the water pipe by exchanging heat with the water inside is formed. Here, the water pipe is made of stainless steel.

  In this water heat exchanger, corrosion of the water pipe due to water can be made difficult to occur.

  Thereby, the corrosion resistance of the water pipe can be improved in the water heat exchanger having a three-layer pipe structure with a flat pipe and exchanging heat between the refrigerant and the water.

  A water heat exchanger according to a second aspect is the water heat exchanger according to the first aspect, wherein the three-layer pipe is formed in a straight tube and a plurality of pipes, and the first refrigerant header, the second refrigerant header, and the first water. It further has a header and a second water header. The first refrigerant header is connected to one end in the longitudinal direction of the refrigerant pipe constituting the plurality of three-layer pipes. The second refrigerant header is connected to the other end in the longitudinal direction of the refrigerant pipe constituting the plurality of three-layer pipes. The first water header is connected to one end in the longitudinal direction of the water pipe constituting the plurality of three-layer pipes. The second water header is connected to the other end in the longitudinal direction of the water pipe constituting the plurality of three-layer pipes. Each water pipe is connected to the first and second water headers without bending the one end and the other end in the longitudinal direction of the water pipe, and each refrigerant pipe is connected to one end of the refrigerant pipe in the longitudinal direction and the other. The ends are bent and connected to the first and second refrigerant headers.

  When the water pipe constituting the three-layer pipe is made of stainless steel, since the strength of stainless steel is high, water of a three-layer pipe structure using a conventional flat pipe is used to secure a sufficient heat transfer area. This is not suitable for bending a three-layer tube such as a heat exchanger.

  In view of this, this water heat exchanger employs a structure in which the three-layer pipes are formed into a plurality of straight pipes, and both end portions in the longitudinal direction of these three-layer pipes are header-connected. However, when adopting such a header connection structure, it is necessary to dispose the first and second refrigerant headers for the refrigerant pipe and the water pipe so as not to interfere with each other. For this reason, in this water heat exchanger, while adopting the header connection structure, the longitudinal direction both ends of the stainless steel water pipe are connected to the first and second water headers without bending, and the longitudinal direction of the refrigerant pipe A structure is adopted in which both ends are bent and connected to the first and second refrigerant headers.

  As a result, in a water heat exchanger that has a three-layer tube structure with flat tubes and heat-exchanges refrigerant and water, it is possible to improve the corrosion resistance of the water tube, and without sufficient bending of the high-strength water tube. A heat transfer area can be secured.

  A water heat exchanger according to a third aspect is the water heat exchanger according to the second aspect, wherein the refrigerant and water flow in series in a plurality of three-layer pipes inside the refrigerant header and the water header. A partition plate is provided.

  In this water heat exchanger, the refrigerant and water flow in series through a plurality of three-layer pipes via the header.

  As a result, in a water heat exchanger having a three-layer tube structure with a flat tube and exchanging heat between the refrigerant and water, while improving the corrosion resistance of the water tube, it is long without bending a strong water tube. Heat transfer performance equivalent to that obtained by bending the three-layer tube can be obtained.

  As described above, according to the present invention, the following effects can be obtained.

  In the water heat exchanger according to the first aspect, the corrosion resistance of the water pipe can be improved.

  In the water heat exchanger according to the second aspect, it is possible to secure a sufficient heat transfer area without bending the water pipe having high strength while improving the corrosion resistance of the water pipe.

  In the water heat exchanger according to the third aspect, while improving the corrosion resistance of the water pipe, the heat transfer performance equivalent to that obtained by bending a long three-layer pipe is obtained without bending a high-strength water pipe. be able to.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the heat pump type hot water supply apparatus as 1st Embodiment by which the water heat exchanger concerning this invention was employ | adopted. It is a schematic sectional drawing which shows the inside of a warm water heat source unit. It is a whole block diagram of a water heat exchanger. It is II sectional drawing of FIG. It is II-II sectional drawing of FIG. It is an expanded sectional view of the 3 layer pipe which comprises a water heat exchanger. It is a whole block diagram of the water heat exchanger of the modification 1. It is a whole block diagram of the water heat exchanger of the modification 2. It is II sectional drawing of FIG. It is II-II sectional drawing of FIG. It is sectional drawing of the water pipe which comprises the water heat exchanger of the modification 3. It is sectional drawing of the water pipe which comprises the water heat exchanger of the modification 4. It is a schematic block diagram of the hot water circulation apparatus as 2nd Embodiment by which the water heat exchanger concerning this invention was employ | adopted.

  Hereinafter, an embodiment of a water heat exchanger according to the present invention will be described with reference to the drawings. In addition, embodiment of the water heat exchanger concerning this invention is not restricted to embodiment described below, It can change in the range which does not deviate from the summary of invention.

(1) 1st Embodiment <Whole structure of a heat pump type hot-water supply apparatus>
FIG. 1 is a schematic configuration diagram of a heat pump hot water supply apparatus 1 as a first embodiment in which a water heat exchanger 22 according to the present invention is employed.

  The heat pump hot water supply apparatus 1 mainly includes a hot water heat source unit 2 and a hot water storage unit 3.

  The hot water heat source unit 2 mainly includes a compressor 21, a water heat exchanger 22, an expansion valve 23, and an air heat exchanger 24. The refrigerant circuit 20 is connected by connecting these devices. It is composed.

  The hot water storage unit 3 mainly includes a hot water storage tank 31 and a water circulation pump 32. The water circulation circuit 30 is configured by connecting the water heat exchanger 22, the hot water storage tank 31, and the water circulation pump 32.

<Hot water heat source unit>
FIG. 2 is a schematic cross-sectional view showing the inside of the hot water heat source unit 2.

  In FIG. 2, the right compartment of the heat insulation wall 2c is the machine room 2a, and the left compartment of the heat insulation wall 2c is the fan room 2b. A compressor 21, an expansion valve 23, and the like are disposed in the machine room 2a. A fan 27 is disposed in the fan chamber 2b. A motor (not shown) that drives the fan 27 is disposed behind the fan 27 in a state of being fixed to the motor support base 28. A water heat exchanger 22 is disposed below the fan chamber 2b with a heat insulating wall 2d interposed therebetween. In the water heat exchanger 22, heat exchange is performed between the refrigerant discharged from the compressor 21 and the water discharged from the water circulation pump 32. In FIG. 2, the air heat exchanger 24 is disposed along the left side wall and the back wall of the fan chamber 2b, and the right end of the air heat exchanger 24 extends to the center of the machine chamber 2a. A control box 4 is disposed in the upper part of the machine room 2a.

<Water heat exchanger>
FIG. 3 is an overall configuration diagram of the water heat exchanger 22. 4 is a cross-sectional view taken along the line II of FIG. 5 is a cross-sectional view taken along the line II-II in FIG. FIG. 6 is an enlarged cross-sectional view of the three-layer tube 43 constituting the water heat exchanger 22.

  The water heat exchanger 22 is a heat exchanger that exchanges heat between refrigerant (here, refrigerant discharged from the compressor 21) and water (here, water discharged from the water circulation pump 32). A three-layer pipe 43 including a pair of refrigerant pipes 41 and a water pipe 42 is provided.

  The pair of refrigerant tubes 41 is configured by a multi-hole flat tube having a plurality of (here, eight) refrigerant flow passage holes 41a, and the refrigerant flows through the plurality of refrigerant flow passage holes 41a. Note that the number of the refrigerant flow path holes 41a is not limited to eight, but may be larger than the number of the water flow path holes 42a of the water pipe 42. The refrigerant pipe 41 is made of aluminum or an aluminum alloy, and is manufactured by a drawing process or an extrusion process.

  The water pipe 42 is composed of a small-hole flat tube having a number (here, one) of water flow path holes 42a smaller than the number of the refrigerant flow path holes 41a of the refrigerant pipe 41. Circulate. The water pipe 42 is made of stainless steel such as SUS304 or SUS316, and is manufactured by drawing or bending a plate material.

  The three-layer tube 43 is configured such that both surfaces of the side surface 42 b on the long side of the cross section of the water tube 42 are sandwiched and adhered to one side surface 41 b on the long side of the cross section of the pair of refrigerant tubes 41. The pair of refrigerant pipes 41 and water pipes 42 are in close contact with each other by brazing. The joining of the pair of refrigerant pipes 41 and the water pipes 42 is not limited to brazing, and may be made of an adhesive. The three-layer pipe 43 configured as described above heats the water inside the water pipe 42 by exchanging heat between the refrigerant flowing inside the pair of refrigerant pipes 41 and the water inside the water pipe 42. It has become.

  Thus, in this water heat exchanger 22, since the water pipe 42 is made of stainless steel, the water pipe 42 can be hardly corroded by water, and the corrosion resistance of the water pipe 42 can be improved.

  However, as described above, when the water pipe 42 constituting the three-layer pipe 43 is made of stainless steel, since the strength of the stainless steel is high, in order to ensure a sufficient heat transfer area, This is not suitable for bending a three-layer tube such as a water heat exchanger having a three-layer tube structure with a flat tube.

  In view of this, the water heat exchanger 22 adopts a structure in which the three-layer tube 43 is formed in a straight tube shape and has a plurality of (here, 11), and both longitudinal ends of the three-layer tube 43 are header-connected. . Specifically, in the water heat exchanger 22, a first refrigerant header 44, a second refrigerant header 45, a first water header 46, and a second water header 46 are provided along with a plurality of three-layer pipes 43. It has been. The first refrigerant header 44 is connected to one end 41c in the longitudinal direction of the refrigerant pipe 41 constituting the plurality of three-layer pipes 43. The second refrigerant header 45 is connected to the other end 41 d in the longitudinal direction of the refrigerant pipe 41 constituting the plurality of three-layer pipes 43. The first water header 46 is connected to one end portion 42 c in the longitudinal direction of the water pipe 42 constituting the plurality of three-layer pipes 43. The second water header 47 is connected to the other end 42d in the longitudinal direction of the water pipe 42 constituting the plurality of three-layer pipes 43. Here, the plurality of three-layer tubes 43 are arranged in multiple stages in a state in which the surfaces on the long side of the cross section face each other. And the cylindrical headers 44 and 46 extended along the direction of the multistage arrangement | sequence of the some 3 layer pipe | tube 43 are arrange | positioned at the longitudinal direction one end side (here one end part 41c, 42c side) of the some 3 layer pipe | tube 43 Has been. Also, the cylindrical headers 45 and 47 extending along the direction of the multi-stage arrangement of the plurality of three-layer tubes 43 are the other ends in the longitudinal direction of the plurality of three-layer tubes 43 (here, the other end portions 41d and 42d side). Is arranged. Thereby, 11 sets of parallel heat exchange flow paths are formed.

  However, when adopting such a header connection structure, it is necessary to arrange the first and second refrigerant headers 44 and 45 for the refrigerant pipe 41 so as not to interfere with each other. For this reason, in this water heat exchanger 22, while adopting a header connection structure, the first and second water headers 46, 47 are formed without bending the longitudinal ends 42c, 42d of the water pipe 42 made of stainless steel. A structure is employed in which both ends 41c and 41d in the longitudinal direction of the refrigerant pipe 41 are bent and connected to the first and second refrigerant headers 44 and 45, respectively. Here, the 1st and 2nd water headers 46 and 47 are arrange | positioned in the position corresponding to the front-end | tip of the longitudinal direction both ends 42c and 42d of the straight tubular water pipe 42, and the 1st and 2nd refrigerant | coolant headers 44 and 45 are water pipes. 42 is shifted to the side orthogonal to the longitudinal direction (upper side in FIG. 4). Then, the longitudinal ends 42c and 42d of the water pipe 42 are connected to the first and second water headers 46 and 47 without bending, and only the longitudinal ends 41c and 41d of the refrigerant pipe 41 are bent and processed. The first and second refrigerant headers 44 and 45 are connected.

  Thereby, in this water heat exchanger 22, while ensuring the corrosion resistance of the water pipe 42 by making the water pipe 42 from stainless steel, a sufficient heat transfer area is ensured without bending the high-strength water pipe 42. be able to.

  It is also conceivable to apply an anticorrosion coating to the inner surface of the water pipe 42 without making the water pipe 42 of stainless steel. However, in this case, the structure of the water pipe 42 is complicated and bending is allowed, but depending on the degree of bending, the anticorrosion coating may be peeled off and corrosion resistance may be impaired. For this reason, in this water heat exchanger 22, the structure which made the material itself of the water pipe 42 into the corrosion-resistant stainless steel as mentioned above is employ | adopted.

<Modified example of water heat exchanger>
-1-
In the water heat exchanger 22 described above, a plurality of (specifically, 11) parallel heat exchange channels are formed by the plurality of three-layer tubes 43 and the headers 44 to 47 to ensure a heat transfer area. I am doing so. For this reason, the refrigerant and water that have flowed into the water heat exchanger 22 are branched into eleven three-layer pipes 43 in the first refrigerant header 44 and the first water header 46. The branched refrigerant and water pass through these three-layer pipes 43 and then merge at the second refrigerant header 445 and the second water header 47 to flow out of the water heat exchanger 22. . That is, in the water heat exchanger 22, the refrigerant and water pass through the three-layer pipe 43 only once.

  However, depending on the heat exchange conditions between the refrigerant and water, the heat transfer performance equivalent to that obtained by bending a long three-layer tube may be required.

  Therefore, here, as shown in FIG. 7, partition plates 54 a, 55 a, 56 a, and 57 a are provided inside the headers 54 to 57 so that the refrigerant and water flow in series through the plurality of three-layer pipes 43. A water heat exchanger 52 is employed. Therefore, the refrigerant that has flowed into the water heat exchanger 52 is branched into three three-layer pipes 43 by the refrigerant partition plate 54 a in the first refrigerant header 54. The branched refrigerant passes through these three-layer pipes 43 and then merges in the second refrigerant header 55. The merged refrigerant is branched into four three-layer pipes 43 by the refrigerant partition plate 55 a in the second refrigerant header 55. The branched refrigerant passes through these three-layer pipes 43 and then merges in the first refrigerant header 54. Then, the merged refrigerant is branched into the remaining four three-layer pipes 43 in the first refrigerant header 54. The branched refrigerant passes through these three-layer pipes 43 and then merges in the second refrigerant header 55 and flows out of the water heat exchanger 52. Further, the water flowing into the water heat exchanger 52 is branched into four three-layer pipes 43 by the water partition plate 57 a in the second water header 57. The branched water passes through these three-layer pipes 43 and then merges at the first water header 56. The merged water is branched into four three-layer pipes 43 by the water partition plate 56 a in the first water header 56. Then, the branched water passes through these three-layer pipes 43 and then merges in the second water header 57. Then, the merged water is branched into the remaining three three-layer pipes 43 in the second water header 57. The branched water passes through these three-layer pipes 43 and then merges in the first water header 56 and flows out of the water heat exchanger 52. That is, in the water heat exchanger 52, the refrigerant and water pass through the three-layer tube 43 three times in series through the headers 54 to 57 provided with the partition plates 54a, 55a, 56a, and 57a. ing.

  Thereby, in this water heat exchanger 52, the water pipe 42 is made of stainless steel, thereby improving the corrosion resistance of the water pipe 42 and bending the long three-layer pipe without bending the high-strength water pipe 42. Heat transfer performance equivalent to the case of processing can be obtained.

-2-
In the above-described water heat exchangers 22 and 52, a plurality of three-layered tubes 43 are arranged in multiple stages with the surfaces on the long side of the cross section facing each other. However, the multi-stage arrangement of the plurality of three-layer tubes 43 is not limited to this, and as shown in FIGS. 8 to 10, the plurality of three-layer tubes 43 are arranged in a state where the short side surfaces face each other. You may employ | adopt the water heat exchanger 62 arrange | positioned in multiple stages.

  In this water heat exchanger 62, the three-layer tube 43 is formed in a straight tube shape and plural (here, eight), and both longitudinal ends of the three-layer tube 43 are connected to the headers 64 to 67. . The plurality of three-layer tubes 43 are arranged in multiple stages with the short side surfaces facing each other. And the cylindrical headers 64 and 66 extended along the direction of the multistage arrangement | sequence of the some 3 layer pipe | tube 43 are arrange | positioned in the longitudinal direction one end side (here one end part 41c, 42c side) of the some 3 layer pipe | tube 43 Has been. The cylindrical headers 65 and 67 extending along the direction of the multi-stage arrangement of the plurality of three-layer tubes 43 are the other ends in the longitudinal direction of the plurality of three-layer tubes 43 (here, the other end portions 41d and 42d side). Are arranged. Again, the longitudinal ends 42c, 42d of the stainless steel water pipe 42 are connected to the first and second water headers 66, 67 without bending, and the longitudinal ends 41c, 41d of the refrigerant pipe 41 are bent. The structure which processes and connects to the 1st and 2nd refrigerant | coolant headers 64 and 65 is employ | adopted. Specifically, the first and second water headers 66 and 67 are arranged at positions corresponding to the tips of the longitudinal ends 42c and 42d of the straight tubular water pipe 42, and the first and second refrigerant headers 64 and 65 are disposed. The first and second water headers 66 and 67 are arranged so as to be shifted further to the side farther in the longitudinal direction of the water pipe 42 (in FIG. 9, the left and right sides of the drawing). Then, both longitudinal ends 42c and 42d of the water pipe 42 are connected to the first and second water headers 66 and 67 without bending, and only the longitudinal ends 41c and 41d of the refrigerant pipe 41 are bent and processed. The first and second refrigerant headers 64 and 65 are connected.

  Further, here, the partition plates 64a, 64b, 65a, 66a, 66b, 67a are provided inside the headers 64 to 67 so that the refrigerant and water flow in series through the plurality of three-layer pipes 43. . For this reason, the refrigerant that has flowed into the water heat exchanger 62 is branched into two three-layer pipes 43 by the refrigerant partition plate 64 a in the first refrigerant header 64. The branched refrigerant passes through these three-layer pipes 43 and then merges in the second refrigerant header 65. Then, the merged refrigerant is branched into two three-layer pipes 43 by the refrigerant partition plate 65 a in the second refrigerant header 65. The branched refrigerant passes through these three-layer pipes 43 and then merges in the first refrigerant header 64. Then, the merged refrigerant is branched into two three-layer pipes 43 by the refrigerant partition plate 65 b in the first refrigerant header 64. The branched refrigerant passes through these three-layer pipes 43 and then merges in the second refrigerant header 67. Then, the merged refrigerant is branched into the remaining two three-layer pipes 43 in the second refrigerant header 67. The branched refrigerant passes through these three-layer pipes 43 and then merges at the first refrigerant header 64 to flow out of the water heat exchanger 62. The water flowing into the water heat exchanger 62 is branched into two three-layer pipes 43 by the water partition plate 66 a in the first water header 66. The branched water passes through these three-layer pipes 43 and then merges at the second water header 67. Then, the merged water is branched into two three-layer pipes 43 by the water partition plate 67 a in the second water header 67. The branched water passes through these three-layer pipes 43 and then merges at the first water header 66. The merged water is branched into two three-layer pipes 43 by the water partition plate 66 b in the first water header 66. Then, the branched water passes through these three-layer pipes 43 and then is branched into the remaining two three-layer pipes 43 in the second water header 67. The branched water passes through these three-layer pipes 43 and then merges at the first water header 66 to flow out of the water heat exchanger 62. In other words, in the water heat exchanger 62, the refrigerant and water pass through the three-layer pipe 43 four times in series through the headers 64 to 67 provided with the partition plates 64a, 64b, 65a, 66a, 66b, and 67a. It is supposed to be.

  In this water heat exchanger 62 as well as the water heat exchanger 52, the water pipe 42 is made of stainless steel, thereby improving the corrosion resistance of the water pipe 42, and without bending the high-strength water pipe 42. Heat transfer performance equivalent to that obtained by bending a long three-layer tube can be obtained.

-3-
In the water heat exchangers 22, 52, and 62 described above, the water channel hole 42a of the water pipe 42 has a rectangular cross-sectional shape, but the cross-sectional shape of the water channel hole is not limited to this.

  For example, as shown in FIG. 11, in order to promote heat transfer on the water side, a plurality of dimples 48c are formed, so that a pair of water pipes 48 each having a water flow path hole 48a having irregularities on the inner surface are formed. The refrigerant pipe 41 may constitute a three-layer pipe 73, and the three-layer pipe 73 may constitute the water heat exchanger 72.

-4-
In the water heat exchangers 22, 52, 62, 72 described above, the small hole flat tubes constituting the water tubes 42, 48 are single hole flat tubes having one water flow channel hole 42a, 48a. Is not limited to this.

  For example, as shown in FIG. 12, a three-layer pipe 83 is constituted by a water pipe 49 constituted by a small-hole flat pipe having two water flow path holes 49a and a pair of refrigerant pipes 41. Alternatively, the water heat exchanger 82 may be configured.

(2) Second Embodiment <Overall Configuration of Hot Water Circulation Device>
FIG. 12 is a schematic configuration diagram of a hot water circulation device 101 as a second embodiment in which the water heat exchanger according to the present invention is employed.

  The hot water circulation device 101 mainly includes a heat pump circuit 110, a hot water circulation circuit 160, a hot water supply circuit 190, an intermediate pressure water heat exchanger 140, and a high pressure water heat exchanger 150. The hot water circulation device 101 is a device that not only uses the heat obtained by the heat pump circuit 110 as heat for heating via the hot water circulation circuit 160 but also uses it as heat for hot water supply via the hot water supply circuit 190. The heat pump circuit 110 is provided in the hot water heat source device 102.

<Water heat exchanger>
The intermediate-pressure water heat exchanger 140 and the high-pressure water heat exchanger 150 are heat exchangers that exchange heat between the CO 2 refrigerant that circulates in the heat pump circuit 110 and the water that circulates in the hot water circulation circuit 160. In addition, as the intermediate pressure water heat exchanger 140 and the high pressure water heat exchanger 150, the thing of the structure similar to the water heat exchangers 22, 52, 62, 72 employ | adopted as 1st Embodiment is employ | adopted.

<Heat pump circuit>
The heat pump circuit 110 is a refrigerant circuit using a CO2 refrigerant that is a natural refrigerant. The heat pump circuit 110 mainly includes a low-stage compressor 121, a high-stage compressor 125, an economizer heat exchanger 107, an injection path 170, a primary inter-refrigerant heat exchanger 108, a primary bypass 180, and expansion. It has a valve 105a, an evaporator 104, and a fan 104f.

  The intermediate pressure water heat exchanger 140 is connected between the discharge side of the low stage compressor 121 and the suction side of the high stage compressor 125. In addition, a refrigerant pipe from an injection path 170 (to be described later) joins the refrigerant pipe between the downstream end of the intermediate pressure water heat exchanger 140 and the suction side of the high stage compressor 125.

  The high-pressure water heat exchanger 150 is connected between the discharge side of the high stage compressor 125 and the upstream end in the flow direction of the primary refrigerant toward the expansion valve 105a via the primary refrigerant heat exchanger 108. Has been. In the economizer heat exchanger 107, the downstream end in the flow direction of the primary refrigerant toward the expansion valve 105a is connected to the upstream end of the heat exchanger 108 between the primary refrigerants in the flow direction of the primary refrigerant toward the expansion valve 105a. Has been.

  The primary inter-refrigerant heat exchanger 108 is a heat exchanger that exchanges heat between the primary refrigerant that leaves the economizer heat exchanger 107 and travels toward the expansion valve 105 a and the refrigerant evaporated by the evaporator 104. In the primary inter-refrigerant heat exchanger 108, the flow path through which the former refrigerant flows is referred to as a primary heat exchange high-pressure side flow path 108a, and the flow path through which the latter refrigerant flows is referred to as a primary heat exchange low-pressure side flow path 108b. In the primary inter-refrigerant heat exchanger 108, the downstream end of the primary heat exchange high-pressure side channel 108a is connected to the expansion valve 105a. The primary inter-refrigerant heat exchanger 108 is connected to the downstream end of the evaporator 104 at the upstream end of the primary heat exchanger low-pressure side channel 108b, and to the downstream end of the primary heat exchanger low-pressure channel 108b. Is connected to the suction side of the low-stage compressor 121.

  The expansion valve 105 a is connected to the upstream end of the evaporator 104.

  The downstream end of the evaporator 104 is connected to the suction side of the low-stage compressor 121 via the primary heat exchanger low-pressure side flow path 108 b of the primary refrigerant heat exchanger 108.

  The injection path 170 is a refrigerant pipe branched from the refrigerant pipe between the refrigerant pipe downstream end of the high-pressure water heat exchanger 150 and the economizer heat exchanger 107. The injection path 170 has an injection expansion valve 173. In the economizer heat exchanger 107, heat exchange is performed between the refrigerant that flows through the injection path 170 and is decompressed by the injection expansion valve 173, and the refrigerant that is radiated by the high-pressure water heat exchanger 150. That is, the refrigerant flowing through the injection passage 170 is decompressed by the injection expansion valve 173, and then exchanges heat with the high-pressure side refrigerant by the economizer heat exchanger 107, and joins the suction side of the high-stage compressor 125. Become.

  Thus, in the heat pump circuit 110, since the injection path 170 is employ | adopted, the coefficient of performance of the heat pump circuit 110 can be improved. Even when the cooling effect of the primary refrigerant in the intermediate pressure water heat exchanger 140 for improving the efficiency of the heat pump circuit 110 cannot be sufficiently obtained, for example, when the heating load is small, the injection path 170 is Driving efficiency can be improved by increasing the amount of injection that passes. In the heat pump circuit 110, since the injection path 170 is merged between the intermediate pressure water heat exchanger 140 and the high stage compressor 125, the high temperature primary refrigerant discharged from the low stage compressor 121. Is not cooled before reaching the intermediate pressure water heat exchanger 140, and can be supplied to the intermediate pressure water heat exchanger 140 while maintaining a high temperature state. For this reason, the water for heating which passes the intermediate pressure water heat exchanger 140 can be made into high temperature sufficiently.

  The primary bypass 180 bypasses the primary heat exchange high-pressure side flow path 108a of the primary refrigerant heat exchanger 108. The primary bypass 180 is provided with a primary bypass expansion valve 105b.

  Thus, since the primary bypass expansion valve 105b is provided in the primary bypass 180, the control part 111 can adjust the quantity of the primary refrigerant which passes the primary heat exchanger 108 side. For this reason, it is possible to adjust the primary refrigerant sucked by the low-stage compressor 121 to have an appropriate degree of superheat. Specifically, when the valve opening degree of the primary bypass expansion valve 105 b is lowered, the control unit 111 increases the flow rate of the primary refrigerant passing through the primary inter-refrigerant heat exchanger 108, and the low-stage compressor 121. Therefore, the degree of superheat of the primary refrigerant sucked in can be increased, and the compression ratio required for the refrigerant temperature discharged from the low-stage compressor 121 to reach the target temperature can be kept small. Further, when the valve opening degree of the primary bypass expansion valve 105b is increased, the control unit 111 decreases the flow rate of the primary refrigerant passing through the primary inter-refrigerant heat exchanger 108, and the low-stage compressor 121 sucks it. The degree of superheat of the primary refrigerant can be lowered, and this can avoid a situation where the suction refrigerant density of the low-stage compressor 121 is significantly reduced and the circulation amount cannot be secured.

<Hot water circulation circuit>
The hot water circulation circuit 160 circulates water as a secondary refrigerant. The hot water circulation circuit 160 mainly includes a radiator 161, a hot water pump 163, a hot water mixing valve 164, a hot water forward pipe 165, a hot water return pipe 166, an intermediate pressure side branch 167, a high pressure side branch 168, and hot water storage. A tank 191, a hot water branch valve 192, and a hot water supply side branch 195 are provided.

  The hot water branch valve 192 divides the hot water heated by the intermediate pressure water heat exchanger 140 or the high pressure water heat exchanger 150 into the radiator 161 and the hot water storage tank 191 according to each heat load.

  The radiator 161 is a heat exchanger that is installed in a space to be heated, and warms the air in the target space by heating warm water as a secondary refrigerant through the inside. The radiator 161 is a return port for receiving warm water sent from the hot water pump 163, and a return for sending water that has radiated heat in the radiator 161 to the intermediate-pressure water heat exchanger 140 and the high-pressure water heat exchanger 150. And a mouth. The hot water outgoing pipe 165 is connected to the outgoing port of the radiator 161, and the hot water return pipe 166 is connected to the return port of the radiator 161.

  The water branched in the hot water supply side branch 195 exchanges heat with hot water stored in the hot water storage tank 191 in the hot water heat exchange section 191a in the hot water storage tank 191 to heat the hot water. To dissipate heat. The hot water return pipe 166 is connected to the circulation return port of the hot water storage tank 191, and the water radiated in the hot water supply heat exchange section 191 a joins the hot water return pipe 166. Here, the hot water storage tank 191 is provided with a circulation outlet and a circulation return port.

  The hot water return pipe 166 includes an intermediate pressure side branch passage 167 that sends the water that has radiated heat in the radiator 161 or the hot water storage tank 191 to the intermediate pressure water heat exchanger 140 side, and a high pressure side branch passage that sends the water to the high pressure water heat exchanger 150 side. And 168.

  In the hot water storage tank 191, after passing external city water (not shown), normal temperature water is supplied from the vicinity of the lower end of the hot water storage tank 191 into the hot water storage tank 191 through the water supply pipe 194.

  The hot water supply pipe 198 guides the hot water stored in the hot water storage tank 191 from the vicinity of the upper end of the hot water storage tank 191 to a place to be used (not shown). The hot water supply pipe 198 joins the flow from the hot water storage tank 191 toward the place where it is used. The water supply pipe 194 is branched by a hot water supply bypass pipe 199 from the flow toward the hot water storage tank 191 side. The hot water supply bypass pipe 199 is connected to a hot water supply mixing valve 193 provided in the hot water supply pipe 198. The hot water mixing valve 193 can adjust the mixing ratio between hot water sent from the hot water storage tank 191 through the hot water supply pipe 198 and normal temperature water supplied from city water through the hot water supply bypass pipe 199. By adjusting the mixing ratio in the hot water mixing valve 193, the temperature of the water sent to the place to be used is adjusted.

  The water branched in the intermediate pressure side branch passage 167 is heated by exchanging heat with the CO 2 refrigerant, which is the primary refrigerant, in the intermediate pressure water heat exchanger 140, and joined to the hot water outlet pipe 165 by the hot water mixing valve 164. Here, in the intermediate-pressure water heat exchanger 140, the CO2 refrigerant as the primary refrigerant and the water as the heating / hot water supply secondary refrigerant flow in directions opposite to each other.

  The water branched in the high-pressure side branch 168 is heated by exchanging heat with the CO 2 refrigerant, which is the primary refrigerant, in the high-pressure water heat exchanger 150, and is joined to the hot water forward pipe 165 by the hot water mixing valve 164. Here, in the high-pressure water heat exchanger 150, the CO 2 refrigerant as the primary refrigerant and the water as the secondary refrigerant for heating / hot water flow in directions opposite to each other.

<Features>
As described above, the intermediate-pressure water heat exchanger 140 and the high-pressure water heat exchanger 150 that constitute the hot water circulation device 101 of the present embodiment serve as the water heat exchanger 22 that constitutes the heat pump hot water supply device 1 of the first embodiment. , 52, 62, 72, and 82 are employed.

  For this reason, also in the intermediate-pressure water heat exchanger 140 and the high-pressure water heat exchanger 150, it is possible to obtain the same operational effects as the water heat exchangers 22, 52, 62, 72, 82 in the first embodiment.

  The present invention is widely applicable to a water heat exchanger having a three-layer tube structure of flat tubes and exchanging heat between refrigerant and water.

22, 52, 62, 72, 82 Water heat exchanger 41 Refrigerant pipe 41a Refrigerant flow path hole 42, 48, 49 Water pipe 42a, 48a, 49a Water flow path hole 43, 73, 83 Three-layer pipe 44, 45, 54, 55 , 64, 65 Refrigerant header 46, 47, 56, 57, 66, 67 Water header 140 Intermediate pressure water heat exchanger 150 High pressure water heat exchanger 54a, 55a, 64a, 64b, 65a Refrigerant divider 56a, 57a, 66a, 66b, 67a Water divider

JP 2010-190564 A

Claims (3)

A water heat exchanger for exchanging heat between refrigerant and water,
A plurality of flat tubes having a plurality of refrigerant flow holes (41a), a pair of refrigerant tubes (41) through which the refrigerant flows through the plurality of refrigerant flow holes;
A water pipe that is constituted by a small-hole flat pipe having a smaller number of water flow path holes (42a, 48a, 49a) than the number of the refrigerant flow path holes of the refrigerant pipe, and through which the water flows. (42, 48, 49),
With
The both sides of the side surface on the long side of the cross section of the water pipe are sandwiched and closely adhered to one side surface of the long side of the cross section of the pair of refrigerant tubes, so that the refrigerant flowing through the inside of the pair of refrigerant tubes is It constitutes a three-layer pipe (43, 73, 83) that heats the water inside the water pipe by exchanging heat with the water inside the water pipe,
The water pipe is made of stainless steel.
Water heat exchanger (22, 52, 62, 72, 82, 140, 150). The three-layer tube (43, 73, 83) is a straight tube, and there are a plurality of the tubes.
A first refrigerant header (44, 54, 64) to which one longitudinal end of the refrigerant pipe (41) constituting the plurality of three-layer pipes is connected; and the refrigerant pipe constituting the plurality of three-layer pipes. The second refrigerant header (45, 55, 65) to which the other end in the longitudinal direction is connected and the one end in the longitudinal direction of the water pipe (42, 48, 49) constituting the plurality of three-layer pipes are connected. 1 water header (46, 56, 66) and a second water header (47, 57, 67) to which the other end in the longitudinal direction of the water pipe constituting the plurality of three-layer pipes is further connected ,
Each of the water pipes is connected to the first and second water headers without bending the one end and the other end in the longitudinal direction of the water pipe,
Each refrigerant pipe is connected to the first and second refrigerant headers by bending one end and the other end in the longitudinal direction of the refrigerant pipe.
The water heat exchanger (22, 52, 62, 72, 82, 140, 150) according to claim 1. Inside the refrigerant header (54, 55, 64, 65) and the water header (56, 57, 66, 67), the refrigerant and the water pass through the plurality of three-layer pipes (43, 73, 83). Partition plates (54a, 55a, 64a, 64b, 65a, 56a, 57a, 66a, 66b, 67a) are provided so as to flow in series.
The water heat exchanger (22, 52, 62, 72, 82, 140, 150) according to claim 2.

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