JP5117873B2 - Heat exchanger, heat pump water heater - Google Patents

Description

  The present invention relates to a heat exchanger for heating a fluid such as water or brine (antifreeze) by a refrigerant circulated in a heat pump cycle, and a heat pump water heater provided with the heat exchanger, and in particular, the refrigerant is circulated in the heat exchanger. The present invention relates to a technique for detecting the temperature of a refrigerant in a refrigerant pipe.

Conventionally, it has a heat pump cycle connected to a compressor, expansion valve, water heat exchanger, outdoor air heat exchanger, etc., and it can be used for hot water supply, bathroom, heating, etc. by heat exchange with the refrigerant circulated in the heat pump cycle. A heat pump type water heater (system) that heats water to be used is known (for example, see Patent Document 1).
In the water heat exchanger, for example, a refrigerant pipe through which a refrigerant circulated in the heat pump cycle and a water pipe through which water heated by heat exchange with the refrigerant circulates are spirally stacked. Used. FIG. 6 shows a cross-sectional view of a main part of a water heat exchanger Z used in a conventional heat pump type hot water heater.
As shown in FIG. 6, in the water heat exchanger Z, a refrigerant pipe 101, a hot water supply water pipe 102, and a floor heating water pipe 103 are laminated in this order. Here, in the water heat exchanger Z, the refrigerant pipe 101 and the water pipes 102 and 103 are brazed to increase the heat transfer coefficient between the refrigerant pipe 101 and the water pipes 102 and 103. In the water heat exchanger Z, heat is exchanged between the refrigerant in the refrigerant pipe 101 and the water in the water pipes 102 and 103, and the water in the water pipes 102 and 103 is heated.
Further, the water heat exchanger Z is provided with a temperature sensor 104 such as a thermocouple for measuring the temperature (condensation temperature) of the refrigerant condensed in the water heat exchanger Z near the center of the pipe length of the refrigerant pipe 101. It has been. The condensation temperature measured by the temperature sensor 104 is used for controlling a compressor, an expansion valve, a fan of an outdoor air heat exchanger, and the like provided on the heat pump cycle.
JP 2003-65602 A

However, in the state where the refrigerant pipe 101 and the water pipes 102 and 103 are laminated and brazed as in the heat exchanger Z, the condensation temperature detected by the temperature sensor 104 is the water temperature in the water pipes 102 and 103. There was a problem that it was lower than the original condensing temperature under the influence of. For example, a temperature difference of about 10 to 15 ° C. occurs between the temperature detected by the temperature sensor 104 and the actual condensation temperature. At this time, it is conceivable that the temperature detected by the temperature sensor 104 is corrected according to a predetermined relational expression or the like so as to approximate the actual condensing temperature. However, the time until the condensing temperature is stabilized after the heat pump unit is operated. Since the relationship between the actual condensing temperature and the temperature detected by the temperature sensor 104 is also unstable, it is difficult to determine the relational expression so that the correction is properly performed.
Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat exchanger capable of accurately detecting the refrigerant temperature in the refrigerant pipe in the heat exchanger and the heat exchanger. Another object is to provide a heat pump type hot water heater.

To achieve the above object, the present invention includes a refrigerant pipe through which a refrigerant circulated in a heat pump cycle flows, and one or a plurality of heated fluid pipes through which a heated fluid heated by heat exchange with the refrigerant flows. And is applied to a heat exchanger in which the refrigerant pipe and the heated fluid are brazed, wherein the refrigerant pipe and the heated fluid pipe are laminated. And a non-brazing portion that does not braze the refrigerant pipe and the heated fluid pipe is formed in a part of the laminated portion in which the non-brazing portion is placed in contact with the non-brazing portion. It is comprised as a heat exchanger characterized by including the refrigerant temperature detection means which detects the temperature of the refrigerant | coolant which distribute | circulates to a brazing part. Further, the present invention may be understood as an invention of a heat pump type water heater provided with the heat exchanger.
In the heat exchanger configured as described above, the refrigerant temperature detection means is disposed in contact with the non-brazed portion having a low heat transfer coefficient between the refrigerant pipe and the heated fluid pipe. In the state where the influence of the temperature of the fluid to be heated in the fluid-to-be-added fluid pipe is small, the refrigerant temperature detection means can detect the temperature with high accuracy. Therefore, for example, in a heat pump type water heater provided with the heat exchanger, the operation of the heat pump type hot water heater can be appropriately controlled based on the temperature of the refrigerant with high accuracy detected by the refrigerant temperature detecting means. Moreover, in the heat exchanger of this invention, the said non-brazing part may be provided in the approximate center part of the piping length of the said refrigerant | coolant piping. With such a configuration, the temperature of the refrigerant can be detected more accurately.
Furthermore, it is preferable that the refrigerant temperature detecting means is provided at a substantially central portion of the non-brazing portion. In this way, since the refrigerant temperature can be detected at a position away from the brazing part on both sides of the non-brazing part, it is less affected by the fluid temperature in the heated fluid pipe, The detection accuracy by the refrigerant temperature detection means increases.
More specifically, in the present invention, the heated fluid pipe includes a hot water supply water pipe through which hot water supply water circulates and a heating water pipe through which heating water circulates, and the refrigerant pipe is the hot water supply water. Application to a configuration in which the refrigerant pipe, the hot water supply water pipe, and the heating water pipe are stacked so as to be sandwiched between the pipe and the heating water pipe is preferable.

Further, as the heat transfer coefficient between the refrigerant pipe and the heated fluid pipe in the non-brazing portion is lowered, the refrigerant temperature detecting means can detect the refrigerant temperature more accurately.
Therefore, the refrigerant pipe in the non-brazing part is formed in a flat shape or an elliptical shape having a major axis in a direction perpendicular to the stacking direction so that the refrigerant pipe and the heated fluid pipe are separated from each other in the non-brazing part. It is conceivable to form it. As a result, a gap is formed between the refrigerant pipe and the heated fluid pipe in the non-brazed portion, so that the heat transfer coefficient between the refrigerant pipe and the heated fluid pipe can be further reduced. , The detection accuracy by the refrigerant temperature detection means can be further increased.
Further, as another method, either one or both of the refrigerant pipe and the heated fluid pipe in the non-brazing portion is a direction perpendicular to the stacking direction and the refrigerant pipe in the non-brazing portion. It is also conceivable to form a protrusion in a direction away from the heated fluid piping. Also in this case, since a gap is formed between the refrigerant pipe and the heated fluid pipe in the non-brazed portion, the heat transfer coefficient between the refrigerant pipe and the heated fluid pipe is further reduced. The detection accuracy by the refrigerant temperature detection means can be further increased.
Moreover, it is desirable to provide a heat insulating material between the refrigerant pipe and the heated fluid pipe in the non-brazing portion. As a result, the refrigerant pipe and the heated fluid pipe can be insulated, and the refrigerant temperature detection accuracy by the refrigerant temperature detection means can be increased.

By the way, the non-brazing portion is provided at a substantially central portion of the refrigerant pipe. When the substantially central portion is a curved portion, the shape of the contact portion of the refrigerant temperature detecting means to the refrigerant pipe is changed. Unless it is curved, it is difficult to ensure a sufficient contact area. Therefore, it is desirable that the non-brazing portion is formed in a straight portion of the refrigerant pipe. In this case, a sufficient contact area can be secured even if the shape of the contact portion of the coolant temperature detecting means to the coolant pipe is a linear shape, and temperature detection can be performed with high accuracy.
In addition, if the length of the non-brazed portion is too short, the influence of the fluid temperature in the heated fluid pipe cannot be sufficiently reduced, and the detection accuracy is lowered. If the length is too long, there arises a problem that the heat exchange efficiency of the refrigerant pipe and the heated fluid pipe is lowered and the energy consumption efficiency is deteriorated.
Therefore, it is desirable that the length of the non-brazing portion is about 200 to 400 mm. Thereby, highly accurate temperature detection by the said refrigerant | coolant temperature detection means can be performed, without degrading energy consumption efficiency as much as possible.

  According to the present invention, the refrigerant temperature detection means is disposed in contact with the non-brazed portion having a low heat transfer coefficient between the refrigerant pipe and the heated fluid pipe. In the state where the influence of the temperature of the fluid to be heated is small, temperature detection with high accuracy can be performed by the refrigerant temperature detection means. Therefore, for example, in a heat pump type water heater provided with the heat exchanger, the operation of the heat pump type hot water heater can be appropriately controlled based on the temperature of the refrigerant with high accuracy detected by the refrigerant temperature detecting means.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
FIG. 1 is a block diagram showing a schematic configuration of a heat pump type water heater X according to the embodiment of the present invention, FIG. 2 is a schematic external view of the water heat exchanger 14 according to the embodiment of the present invention, and FIG. FIG. 4 is a diagram showing a cross section taken along line BB ′ in the enlarged view A of FIG. 2, and FIG. 4 is a graph showing the relationship between the temperature detected by the temperature sensor 15 and the length of the flat portion 41a.
First, the schematic configuration of the heat pump type hot water heater X according to the embodiment of the present invention will be described with reference to FIG. In the present embodiment, the heat pump type water heater X is described as an example in which it has a hot water supply function for supplying hot water and a floor heating function for performing floor heating. However, for example, a reheating function for a bath, It may have a function of an air conditioner (air conditioner).

As shown in FIG. 1, the heat pump type hot water heater X is roughly divided into a heat pump cycle (refrigeration cycle) 1 in which refrigerant is circulated, a hot water supply circuit 2 for supplying hot water, and a floor for performing floor heating. The heating circuit 3 is provided. Here, as the refrigerant circulated in the heat pump cycle 1, for example, a carbon dioxide refrigerant such as a CO ₂ refrigerant or an HFC refrigerant such as R410A is used.
The heat pump type water heater X includes a control unit (not shown) having a CPU, a RAM, a ROM, and the like, and is comprehensively controlled by the control unit. Specifically, the control unit of the heat pump type hot water heater X performs the operation of the heat pump type hot water heater X based on the condensation temperature of the refrigerant (temperature when changing from gas to liquid) detected by the temperature sensor 15 described later. Control.

The heat pump cycle 1 includes a compressor 11 that compresses a refrigerant, and a water heat exchanger 14 that heats the water by exchanging heat between the refrigerant flowing out of the compressor 11 and water (the heat exchange according to the present invention). One example), an expansion valve 13 for expanding the refrigerant flowing out of the water heat exchanger 14, and heat exchange between the refrigerant expanded by the expansion valve 13 and the outdoor air to heat the refrigerant ( That is, the outdoor air heat exchanger 12 (functioning as an evaporator) is provided.
The hot water supply circuit 2 includes a hot water storage tank 21 for storing hot water (for example, about 60 ° C.) heated in the water heat exchanger 14, and a hot water storage tank 21 through a water heat exchanger 14 from a lower layer of the hot water storage tank 21. A circulation pump 22 for circulating water in the upper layer, an electromagnetic three-way valve 24 for switching the supply destination of water from the water supply port 23, and an electromagnetic three-way valve 25 for adjusting the temperature of hot water supplied from the hot water supply port 26 I have.

The floor heating circuit 3 includes a floor heating device 31 that performs floor heating using hot water heated in the water heat exchanger 14, and a circulation pump that circulates water through the water heat exchanger 14 and the floor heating device 31. 32. In the floor heating circuit 3, a case where brine (antifreeze) is used instead of water may be considered.
The basic operation of the heat pump cycle 1, the hot water supply circuit 2, and the floor heating circuit 3 in the heat pump type hot water heater X is not different from the conventional operation, so the description thereof is omitted here.
The heat pump type hot water heater X according to the embodiment of the present invention is characterized by a configuration for detecting the condensing temperature of the refrigerant in the water heat exchanger 14, and will be described below with reference to FIGS. This point will be described.

As shown in FIG. 2, in the water heat exchanger 14, the refrigerant pipe 41 through which the refrigerant circulated in the heat pump cycle 1 circulates, and water heated by heat exchange with the refrigerant (an example of a heated fluid) circulates. A water pipe (an example of a heated fluid pipe) that is spirally wound (coiled) so that a hot water supply water pipe 42 connected to the hot water supply circuit 2 and a heating water pipe 43 connected to the floor heating circuit 3 are laminated. The refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are brazed. For example, the water heat exchanger 14 is formed in a substantially rectangular shape, a substantially circular shape, a substantially flat shape or the like in a plan view, and a concept including a state wound in these shapes is expressed as a spiral shape. Specifically, the water heat exchanger 14 of the present embodiment has a flat shape (for example, a shape like a track in an athletics stadium) that is composed of a straight portion and a curved portion when viewed from above (plan view). ing.
Each of the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 is a circular pipe. A brazing material such as silver brazing, copper brazing, brass brazing, and phosphor copper brazing is used for brazing the refrigerant pipe 41 with the hot water supply water pipe 42 and the heating water pipe 43.
In the water heat exchanger 14, the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are stacked so that the refrigerant pipe 41 is sandwiched between the hot water supply water pipe 42 and the heating water pipe 43. 42, the water in the heating water pipe 43 is heated by heat exchange with the refrigerant in the refrigerant pipe 41. In this way, heat exchange is performed in the laminated portion in which the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are laminated. At this time, the refrigerant in the refrigerant pipe 41 is condensed and liquefied by heat exchange with the water in the hot water supply water pipe 42 and the heating water pipe 43.

Further, the water heat exchanger 14 is provided with a temperature sensor 15 (an example of a refrigerant temperature detecting means) that detects the temperature (condensation temperature) of the refrigerant condensed and liquefied in the water heat exchanger 14. . Here, the temperature sensor 15 is a laminated portion in which the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are laminated, and is disposed at a substantially central portion of the pipe length of the refrigerant pipe 41. Specifically, the temperature sensor 15 may be one that detects the temperature using a thermocouple, but is not limited to this, and for example, a temperature sensor such as a thermistor can be used. Further, the arrangement position of the temperature sensor 15 may be a position shifted from the central portion as long as it can detect a temperature equivalent to the central portion of the pipe length of the refrigerant pipe 41.
The condensation temperature detected by the temperature sensor 15 is input to a control unit (not shown) of the heat pump type hot water heater X via an electric circuit (not shown) to which the temperature sensor 15 is connected.
In the heat pump type hot water heater X, the control unit (not shown), based on the condensation temperature detected by the temperature sensor 15, the compressor 11 and the expansion valve 13 provided on the heat pump cycle 1, the outdoor air heat exchange. Various devices such as a fan of the container 12 are controlled.

Here, the enlarged view A shown in FIG. 2 is an enlarged view of the substantially central portion of the pipe length of the refrigerant pipe 41 in the water heat exchanger 14, and FIG. 3 is a cross-sectional view taken along the line BB ′ in the enlarged view A of FIG. (A) is a perspective view, (b) is a front view.
As shown in the enlarged views A and 3 of FIG. 2, the water heat exchanger 14 is a laminated portion in which a refrigerant pipe 41, a hot water supply water pipe 42, and a heating water pipe 43 are laminated. A flat portion 41 a that is deformed into a flat shape having a long diameter in a direction perpendicular to the stacking direction of the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 is formed at a substantially central portion (an example of a part of the stacked portion). Is formed. Instead of the flat part 41a, an elliptical part deformed into an elliptical shape having a major axis in a direction perpendicular to the stacking direction of the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 may be formed.
In the flat portion 41a, the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are not in contact with each other and are in a separated state. Therefore, when the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are brazed, only the region excluding the flat portion 41a can be brazed. Specifically, the flat portion 41a of the refrigerant pipe 41 includes, for example, the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 stacked in a spiral shape, and then only the refrigerant pipe 41 before brazing. What is necessary is just to form by inserting | pinching with a tool and making it deform | transform. And only the area | region except this flat part 41a can be brazed by performing brazing operation | work, without attaching a brazing material to the flat part 41a.
Thus, in the flat part 41a (an example of a non-brazing part) which is not brazed, the heat transfer coefficient between the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 becomes low, and the refrigerant in the refrigerant pipe 41 Is not exchanged with the water in the hot water supply water pipe 42 and the water in the heating water pipe 43.

In the water heat exchanger 14, as shown in the enlarged view A and FIG. 3 of FIG. 2, the temperature sensor 15 is disposed in contact with the outer periphery of the flat portion 41a formed at the substantially central portion of the pipe length of the refrigerant pipe 41. Has been. Thus, the temperature of the refrigerant flowing in the flat portion 41a is detected by the temperature sensor 15.
As described above, in the water heat exchanger 14, since the heat transfer coefficient between the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 in the flat portion 41a is low, the temperature sensor 15 arranged in contact with the flat portion 41a. The detected temperature is not affected by the water temperature in the hot water supply water pipe 42 and the heating water pipe 43. In the present embodiment, the temperature sensor 15 is provided near the center of the flat portion 41a. In this way, since the refrigerant temperature can be detected at positions away from the brazing parts on both sides of the flat part 41a, it is less susceptible to the influence of the water temperature in the hot water supply water pipe 42 and the heating water pipe 43. Thus, the detection accuracy by the temperature sensor 15 is increased.
Therefore, in the heat pump type hot water heater X, the temperature sensor 15 detects the condensation temperature of the refrigerant in the laminated portion where the refrigerant pipe 41, the hot water supply pipe 42, and the heating water pipe 43 of the water heat exchanger 14 are laminated with high accuracy. Therefore, various controls such as the compressor 11 and the expansion valve 13 provided in the heat pump cycle 1 and the fan of the outdoor air heat exchanger 12 can be appropriately performed based on the condensation temperature. As a result, for example, it is possible to accurately detect the refrigerant condensing temperature in the water heat exchanger 14 even when the heat pump unit 1 starts to operate, and processing such as correcting the temperature detected by the temperature sensor 15 is omitted. It is also possible to do.
In addition, when the flat part 41a is set in the location where the refrigerant | coolant piping 41 was bent in the water heat exchanger 14, there exists a possibility that the contact area of the temperature sensor 15 and the flat part 41a cannot fully be ensured. Therefore, it is desirable that the flat portion 41a is formed in a straight portion of the refrigerant pipe 41 (see FIGS. 2 and 3). For example, when the central portion of the refrigerant pipe 41 is located at the bent portion, the flat portion 41a may be formed by shifting to the linear portion before and after the bent portion.

By the way, as the flat portion 41 a is longer, the water temperature in the hot water supply water pipe 42 and the heating water pipe 43 is less affected by the refrigerant condensing temperature detected by the temperature sensor 15. FIG. 4 shows the relationship between the temperature detected by the temperature sensor 15 and the length of the flat portion 41a. As shown in FIG. 4, if the length of the flat tube 41a is about 200 mm or more, the temperature sensor 15 can obtain a detected temperature that approximates the actual refrigerant condensation temperature. More preferably, it is about 300 mm or more.
However, in the flat part 41a, heat exchange between the refrigerant in the refrigerant pipe 41 and the water in the hot water supply water pipe 42 and the water in the heating water pipe 43 is not performed. Therefore, the longer the flat part 41a, The heat exchange efficiency in the heat exchanger 14 is reduced.
Therefore, the length of the flat part 41a is desirably about 200 to 400 mm with the center at the substantially central part of the pipe length of the refrigerant pipe 41 (for example, a position around 5 m if the total length is 10 m).
With this length, the heat exchange efficiency between the refrigerant in the refrigerant pipe 41 and the water in the hot water supply pipe 42 and the water in the heating water pipe 43 is not greatly reduced, that is, the energy consumption efficiency (COP) is increased. It is possible to realize temperature detection with high accuracy by the temperature sensor 15 without deteriorating.

In the present embodiment, the case where two hot water supply water pipes 42 and a heating water pipe 43 are provided for the refrigerant pipe 41 and a total of three pipes are sequentially stacked has been described as an example. It is not limited to this. For example, the present invention can be applied to a heat exchanger in which two pipes of a refrigerant pipe 41 and a hot water supply water pipe 42 (or a heating water pipe 43) are stacked and bent in a spiral shape.
In addition, it is desirable to provide a heat insulating material (not shown) such as a ceramic plate between the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 in the flat portion 41a. Thereby, the heat transfer between the refrigerant pipe 41 and the hot water supply water pipe 42 and the heating water pipe 43 can be cut off, and the temperature detection accuracy by the temperature sensor 15 can be improved.
In the present embodiment, the flat portion 41a is provided in the refrigerant pipe 41. However, by providing flat portions in the hot water supply water pipe 42 and the heating water pipe 43, the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe are provided. 43 may be provided with a gap between them.

FIG. 5 shows a cross section of the main part of the water heat exchanger 14 ′ according to the first embodiment of the present invention, where (a) is a perspective view, (b) is a front view, and (c) is a front view. A top view is shown. In addition, about the structure similar to the water heat exchanger 14 demonstrated in the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
As shown in FIGS. 5A to 5C, in the water heat exchanger 14 ′ according to the present embodiment, a refrigerant is used instead of the flat portion 41a formed in the water heat exchanger 14 (see FIG. 2). A protruding portion 41 b that protrudes in a direction perpendicular to the stacking direction of the pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 is formed in the refrigerant pipe 41.
In the protrusion 41b, the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are not in contact with each other and are separated from each other. In other words, a gap is formed between the refrigerant pipe 41 and the hot water supply water pipe 42 and the heating water pipe 43. Therefore, when the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are brazed, only the region excluding the protruding portion 41b can be brazed. The protrusion 41b of the refrigerant pipe 41 is formed by, for example, stacking the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 into a spiral shape, and then only the refrigerant pipe 41 with a tool before brazing. What is necessary is just to form by pressing and making it deform | transform.
Thus, in the protrusion part 41b (an example of a non-brazing part) which is not brazed, the heat transfer coefficient between the refrigerant pipe 41 and the hot water supply water pipe 42 and the heating water pipe 43 becomes low, and the refrigerant in the refrigerant pipe 41 Heat exchange between the hot water supply water pipe 42 and the water in the heating water pipe 43 is not performed.

In the water heat exchanger 14 ′, as shown in FIG. 4, the temperature sensor 15 is disposed in contact with the outer periphery of the protruding portion 41 b formed at the substantially central portion of the pipe length of the refrigerant pipe 41.
As described above, in the water heat exchanger 14 ′, the heat transfer coefficient between the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 in the protrusion 41 b is low. Therefore, the temperature sensor disposed in contact with the flat portion 41 a is used. The temperature detected by 15 is not affected by the water temperature in the hot water supply water pipe 42 and the heating water pipe 43.
Accordingly, in the heat pump type hot water heater X, the temperature sensor 15 can detect the condensation temperature of the refrigerant in the water heat exchanger 14 ′ with high accuracy, and the compressor provided in the heat pump cycle 1 based on the condensation temperature. 11, the expansion valve 13, the fan of the outdoor air heat exchanger 12, and the like can be appropriately controlled.

Also in the water heat exchanger 14 ′ according to the present embodiment, heat transfer such as a ceramic plate is provided between the refrigerant pipe 41 and the hot water supply water pipe 42 and the heating water pipe 43 in the protruding portion 41b. It is desirable to reduce the coefficient.
Incidentally, in the water heat exchanger 14 ′ shown in FIG. 5, the case where the protrusion 41b is formed by deforming the refrigerant pipe 41 has been described as an example, but the hot water supply water pipe 42 and the heating water pipe 43 are modified. Or by deforming both the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 so as to protrude in directions away from each other, the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 A configuration is also conceivable in which these are separated.
That is, one or both of the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are formed so as to protrude in a direction perpendicular to the stacking direction and the refrigerant pipe 41 and the heated fluid pipe being separated from each other. Thus, the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 may be relatively spaced apart by a certain distance.

In the embodiment and the first example, the case where the refrigerant pipe 41 is separated from the hot water supply water pipe 42 and the heating water pipe 43 by forming the flat part 41a or the protruding part 41b in the refrigerant pipe 41 is taken as an example. Explained. However, the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are not necessarily separated from each other.
Specifically, when the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are brazed, brazing can be performed without attaching a brazing material to a substantially central portion of the pipe length of the refrigerant pipe 41. Conceivable. As a result, the water heat exchanger 14 is formed with a non-brazed portion where the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 are not brazed. In this non-brazing portion, the heat transfer coefficient between the refrigerant pipe 41, the hot water supply water pipe 42, and the heating water pipe 43 is lowered, so that the detection accuracy of the refrigerant temperature in the refrigerant pipe 41 by the temperature sensor 15 is increased. be able to.
Also in this case, the refrigerant pipe 41 and the hot water supply water pipe 42 are provided as much as possible by providing a heat insulating material such as a ceramic plate between the refrigerant pipe 41 and the hot water supply water pipe 42 and the heating water pipe 43 in the non-brazing portion. It is desirable to reduce the heat transfer coefficient with the heating water pipe 43.

The block diagram which shows schematic structure of the heat pump type water heater which concerns on embodiment of this invention. The external appearance schematic diagram of the heat exchanger which concerns on embodiment of this invention. The figure which shows the B-B 'cross section in the enlarged view A of FIG. The graph which shows the relationship between the detection temperature of a temperature sensor, and the length of a flat part. The figure which shows the principal part cross section of the heat exchanger which concerns on Example 1 of this invention. The figure for demonstrating the structure of the conventional heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Heat pump cycle 2 ... Hot-water supply circuit 3 ... Floor heating circuit 11 ... Compressor 12 ... Outdoor air heat exchanger 13 ... Expansion valve 14, 14 '... Water heat exchanger (an example of the heat exchanger which concerns on this invention)
15 ... Temperature sensor (an example of refrigerant temperature detecting means)
DESCRIPTION OF SYMBOLS 21 ... Hot water storage tank 22 ... Circulation pump 23 ... Water supply port 24, 25 ... Electromagnetic three-way valve 26 ... Hot water supply port 31 ... Floor heating device 32 ... Circulation pump 41 ... Refrigerant piping 41a ... Flat part (an example of a non-brazing part)
41b ... Protruding part (an example of a non-brazing part)
42 ... Hot water supply water pipe (an example of a heated fluid pipe)
43 ... Water piping for heating (an example of heated fluid piping)
X ... Heat pump water heater

Claims (3)

A refrigerant pipe through which the refrigerant circulated in the heat pump cycle circulates and one or more heated fluid pipes through which the heated fluid heated by heat exchange with the refrigerant is stacked in a spiral shape. And a heat exchanger in which the refrigerant pipe and the heated fluid are brazed,
A non-brazing part that does not braze the refrigerant pipe and the heated fluid pipe is formed in a part of the laminated part where the refrigerant pipe and the heated fluid pipe are laminated,
The refrigerant pipe in the non-brazing part is formed in a flat shape or an elliptical shape having a major axis in a direction perpendicular to the stacking direction so that the refrigerant pipe and the heated fluid pipe are separated from each other in the non-brazing part. ,
A heat exchanger comprising refrigerant temperature detection means for detecting the temperature of the refrigerant flowing through the non-brazing part by being disposed in contact with the non-brazing part. The heat exchanger according to claim 1, wherein the non-brazing portion is formed in a straight portion of the refrigerant pipe.   A heat pump type water heater comprising the heat exchanger according to claim 1 or 2.

Images