JP2004301364A - Heat pump hot water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump hot water supply device for reducing the flowing sound of refrigerant even when the temperature of a water to be supplied is higher by arranging an evaporating heat exchanger having a structure in which a refrigerant passage high in rigidity and small in pressure loss. <P>SOLUTION: The evaporating heat exchanger 16 consists of an inlet pipe 16a into which the refrigerant depressurized by an expansion valve 15 flows, heat transfer pipes 16b, 16c to the outer periphery of which a plurality of fin materials for heat exchange with atmospheric air are joined and in which the refrigerant is distributed, and an output pipe 16d out of which heat absorbed refrigerant flows. The inlet pipe 16a is formed thicker than the heat transfer pipes 16b, 16c. Thus, the flowing sound of the refrigerant can be reduced even when the temperature of water to be supplied is higher. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat pump water heater including a hot water storage tank and a hot water supply means including a heat pump cycle for boiling hot water for hot water stored in the hot water storage tank, and particularly relates to a structure of an evaporation heat exchanger that absorbs atmospheric heat and heat. About.
[0002]
[Prior art]
Conventionally, in this type of heat pump hot water supply apparatus, a refrigerant circulation circuit in which a compressor, a heat exchanger for hot water supply, a pressure reducing means for controlling the flow rate of a refrigerant, and a heat exchanger for an evaporator are sequentially connected, a hot water storage tank, a circulation pump, Hot water supply circuit in which hot water exchangers are sequentially connected, flow control means for controlling a flow control valve to keep the boiling temperature, which is the water-side outlet water temperature of the hot water heat exchanger in the hot water supply circuit, and a hot water storage tank There is provided a means for detecting immediately before the completion of boiling, and a control means for changing a valve opening of the pressure reducing means when a signal from the means for detecting immediately before boiling becomes a predetermined signal.
[0003]
As a result, the valve opening degree of the pressure reducing means is changed when the discharge pressure of the compressor approaches to the completion of the boiling and the discharge pressure of the compressor increases. The area of hot water that can be produced is increased. FIG. 6 (a) shows the temperature distribution in the hot water storage tank. The area above the hot water temperature Tu is an area that can be used as effective hot water, and the area below the hot water temperature T3a is the area that can be heated. Thus, the area between the hot water temperature T3a and the hot water temperature T3 can be used effectively (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP, 2002-340440, A
[Problems to be solved by the invention]
However, in this type of heat pump water heater, when the high-temperature feedwater is boiled by controlling the valve opening so as to reduce the high pressure as in Patent Document 1, the refrigerant is transferred from the evaporating heat exchanger immediately before the end of the boiling. There is a problem that the flowing noise increases. This is because, as shown in FIG. 6 (b), when the operation state of the refrigeration cycle is the hot water temperature T2 shown by the solid line in the figure and the hot water temperature T3a shown by the broken line in the figure, the operation of the evaporating heat exchanger is started. At the refrigerant inlet, since the dryness differs greatly at point A2 (for example, about 0.3) and point A3a (for example, about 0.9), point A3a has a larger gas phase than point A2, and therefore has a specific volume. And the flow rate of the refrigerant increases. Therefore, it can be said that when the feedwater temperature is high, the refrigerant flow noise is greater than that of the evaporating heat exchanger.
[0006]
In view of the above, an object of the present invention is to provide an evaporating heat exchanger having a structure in which the refrigerant passage has high rigidity and a small pressure loss. An object of the present invention is to provide a heat pump hot water supply device capable of reducing sound.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the technical means described in claims 1 to 7 is adopted. That is, according to the first aspect of the present invention, water is supplied from the water supply source to the water supply side, and a hot water storage tank (1) for storing hot water for hot water supply on the hot water storage side, and a compressor (13) for compressing a refrigerant, the compressor (13) includes: A hot water supply heat exchanger (14) for exchanging heat between the high-pressure refrigerant discharged from the machine (13) and water taken from the water supply side of the hot water storage tank (1), a pressure reducing means (15), and evaporation for absorbing atmospheric heat. Pump hot water supply apparatus comprising: a hot water supply means (2) in which a heat exchanger (16) for use is sequentially connected by a refrigerant pipe in a ring shape;
The evaporating heat exchanger (16) has an inlet pipe (16a) into which the refrigerant decompressed by the decompression means (15) flows, and a plurality of fin materials that exchange heat with the atmosphere are joined to the outer periphery to distribute the refrigerant inside. The heat transfer pipes (16b, 16c) and the outlet pipe (16d) through which the heat-absorbed refrigerant flows out. The inlet pipe (16a) has the thickness of the heat transfer pipe (16b, 16c). ) Is characterized in that it is formed thicker.
[0008]
According to the first aspect of the present invention, in this type of hot water supply apparatus, the hot water is heated immediately before the completion of the heating, so that the inlet pipe (16a) of the evaporating heat exchanger (16). A refrigerant having a high degree of dryness is introduced into the cooling medium. Therefore, in the present invention, the wall thickness of the inlet pipe (16a) is made thicker than that of the heat transfer pipes (16b, 16c), so that the rigidity of the inlet pipe (16a) is increased, so that a sound insulation effect is obtained. Even if the refrigerant flow noise is generated inside the heat exchanger (16), the refrigerant flow noise is not transmitted to the outside, and the refrigerant flow noise can be reduced.
[0009]
According to the second and third aspects of the present invention, the thickness of the inlet pipe (16a) is preferably 12% or more with respect to the pipe diameter, or more preferably, with respect to the pipe diameter. At least 20%.
[0010]
According to the second and third aspects of the present invention, the inventors have studied the relationship between the refrigerant flow noise and the thickness of the inlet pipe (5a). Thus, it was found that the refrigerant flow noise could be reduced by increasing the wall thickness. That is, the flow noise of the refrigerant generated in the inlet pipe (16a) can be reduced by setting the thickness of the inlet pipe (16a) to preferably 12% or more, more preferably 20% or more of the pipe diameter.
[0011]
In the invention described in claim 4, water is supplied from the water supply source to the water supply side, and a hot water storage tank (1) for storing hot water for hot water supply on the hot water storage side, a compressor (13) for compressing a refrigerant, and the compressor ( 13) A hot water supply heat exchanger (14) for exchanging heat between the high pressure refrigerant discharged from the hot water storage tank (1) and water taken from the water supply side of the hot water storage tank (1), a decompression means (15), and evaporation heat for absorbing atmospheric heat. In a heat pump water heater including a water heater (2) in which exchangers (16) are connected in order by refrigerant pipes in a ring shape,
The evaporating heat exchanger (16) has an inlet pipe (16a) into which the refrigerant decompressed by the decompression means (15) flows, and a plurality of fin materials that exchange heat with the atmosphere are joined to the outer periphery to distribute the refrigerant inside. Heat transfer tubes (16b, 16c), and an outlet tube (16d) through which the heat absorbed refrigerant flows out, and the heat transfer tubes (16b, 16c) are located closer to other portions of the heat transfer tubes (16b, 16c). The thickness of the heat transfer tubes (16b, 16c) near the inlet is thicker.
[0012]
According to the fourth aspect of the present invention, in addition to the inlet pipe (16a) described in the first aspect, the heat transfer tubes (16b, 16c) also have a greater wall thickness than the heat transfer tubes (16b, 16c) having the same thickness. By forming the portion near the refrigerant inlet to be thicker than the other portions, a sound insulation effect can be obtained, so that the refrigerant flow noise can be reduced.
[0013]
According to the fifth aspect of the present invention, in the evaporating heat exchanger (16), the plurality of refrigerant passages for dividing the flow of the refrigerant include an inlet pipe (16a), a heat transfer pipe (16b, 16c), and an outlet pipe ( 16d), and is formed so that the number of refrigerant passages decreases sequentially from the inlet pipe (16a) to the downstream of the refrigerant flow.
[0014]
According to the fifth aspect of the invention, since the number of refrigerant passages on the refrigerant inlet side is increased, the pressure loss on the inlet side is reduced, thereby reducing the generation of refrigerant flow noise. .
[0015]
According to the sixth aspect of the present invention, in the evaporating heat exchanger (16), the plurality of refrigerant passages for dividing the flow of the refrigerant include an inlet pipe (16a), a heat transfer pipe (16b, 16c), and an outlet pipe ( 16d), and is formed so that the number of refrigerant passages is sequentially reduced from the inlet pipe (16a) to the downstream of the refrigerant flow, and is increased again.
[0016]
According to the sixth aspect of the invention, the pressure loss of the evaporating heat exchanger (16) is lower than that of the fifth aspect, so that the refrigerant flow noise can be reduced and the thermal efficiency can be improved.
[0017]
In the invention according to claim 7, the hot water supply means (2) is characterized in that the refrigerant is carbon dioxide.
[0018]
According to the seventh aspect of the invention, a supercritical heat pump cycle can be formed by using carbon dioxide as the refrigerant. According to this, hot water can be heated at a higher temperature (for example, about 80 to 90 ° C.) than a general heat pump cycle using a chlorofluorocarbon-based refrigerant, and the boiling operation can be performed even with high-temperature water. It becomes possible.
[0019]
Note that the reference numerals in parentheses of the above means indicate the correspondence with specific means of the embodiment described later.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, a heat pump water heater according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing the overall configuration of the heat pump water heater. First, as shown in FIG. 1, a heat pump hot water supply apparatus includes a hot water storage tank 1 for storing hot water for hot water supply, a heat pump unit 2 serving as hot water supply means for boiling water taken from the hot water storage tank 1, a hot water storage tank 1 and a heat pump unit 2 And a control device 4 for controlling the heat pump unit 2.
[0021]
The hot water storage tank 1 is made of a metal (for example, stainless steel) having excellent corrosion resistance, is formed in a vertically long shape, and a heat insulating material (not shown) is arranged on an outer peripheral portion. It can be kept warm. An inlet 5 is provided on the bottom surface, and an inlet pipe 6 which is a water supply path for introducing tap water into the hot water storage tank 1 is connected to the inlet 5.
[0022]
Upstream of the introduction pipe 12 is connected to tap water via a pressure-reducing check valve (not shown) so that tap water of a predetermined pressure is introduced. On the other hand, an outlet 7 is provided at the top of the hot water storage tank 1, and a hot water supply pipe 8 for discharging hot water in the hot water storage tank 1 is connected to the outlet 7. A discharge pipe provided with a relief valve (not shown) is connected in the middle of the hot water supply pipe 8, and when the pressure in the hot water storage tank 1 rises to a predetermined pressure or more, the hot water in the hot water storage tank 1 is discharged. Is discharged to the outside so as not to damage the hot water storage tank 1 and the like.
[0023]
Further, hot water mixing means (not shown) is connected in the middle of the hot water supply pipe 8 so that hot water in the hot water storage tank 1 and tap water are mixed to obtain hot water at a predetermined temperature. ing. Further, a suction port 1a for sucking water in the hot water storage tank 1 is provided at a lower portion of the hot water storage tank 1, and a discharge port 1b for discharging hot water into the hot water storage tank 1 is provided at an upper portion of the hot water storage tank 1. Have been.
[0024]
Next, the circulation circuit 3 connects the upstream side to the suction port 1 a, connects the downstream side to the discharge port 1 b, and sucks the heat from the suction port 1 a into the hot water supply heat exchanger 14, which will be described later, included in the heat pump unit 2. The water in the hot water storage tank 1 is boiled by exchanging heat between the water in the hot water storage tank 1 and the high-temperature refrigerant and returning the same to the hot water storage tank 1 from the discharge port 1b. 9 is a water supply pump for circulating water in the hot water storage tank 1 in the circulation circuit 3 at the time of boiling, and 10 is a flow control valve as flow control means for controlling a flow rate circulating in the circulation circuit 3. is there.
[0025]
Reference numeral 11 denotes a water temperature sensor for detecting a boiling temperature discharged from a hot water supply heat exchanger 14 described later, and reference numeral 12 denotes a water supply temperature sensor for detecting a temperature of water supplied to the hot water supply heat exchanger 14. The water temperature sensor 11 and the supply water temperature sensor 12 output detected temperature information to the control device 4. The flow rate of the flow control valve 10 is controlled based on the boiling temperature information detected by the water temperature sensor 11. In the present embodiment, the flow rate is controlled so that the boiling temperature becomes constant.
[0026]
Next, the heat pump unit 2 is configured by connecting a compressor 13, a hot water supply heat exchanger 14, a pressure reducing means 15, an evaporating heat exchanger 16 and an accumulator 17 in order in an annular manner through a refrigerant pipe 18, and has a critical temperature as a refrigerant. Low carbon dioxide CO ₂ is used.
[0027]
The compressor 13 is driven by a built-in electric motor (not shown), and compresses and discharges the refrigerant sucked from the accumulator 17 to a critical pressure or higher under general use conditions. The hot water supply heat exchanger 14 exchanges heat between the high-pressure gas refrigerant discharged from the compressor 13 and water taken from the hot water storage tank 1, and includes a refrigerant passage (not shown) through which the refrigerant flows. It has a hot water supply water passage (not shown) through which water flows, and is configured such that the flow direction of the refrigerant and the flow direction of the water are opposed to each other. Since the refrigerant flowing into the refrigerant passage (not shown) is pressurized by the compressor 13 to a pressure higher than the critical pressure, the refrigerant does not condense even if heat is radiated by the hot water supply heat exchanger 14.
[0028]
The expansion valve 15, which is a pressure reducing means, is a pressure reducing device that reduces the pressure of the refrigerant flowing out of the hot water supply heat exchanger 14 in accordance with the valve opening degree, and the valve opening degree is electrically controlled by the control device 4. The evaporating heat exchanger 16 evaporates the refrigerant decompressed by the expansion valve 15 by a heat exchanger with the air blown by a blower (not shown). The accumulator 17 separates the refrigerant evaporated in the evaporating heat exchanger 16 into gas and liquid, stores the liquid refrigerant, causes only the gas-phase refrigerant to be sucked into the compressor 13, and stores the surplus refrigerant during the cycle.
[0029]
Incidentally, the heat pump unit 2 having the above configuration is a supercritical heat pump. This supercritical heat pump refers to a heat pump cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant. Ethylene, ethane, nitric oxide or the like may be used in addition to CO ₂ . Incidentally, according to this supercritical heat pump, hot water can be heated at a higher temperature (for example, about 85 ° C. to 90 ° C.) than a general heat pump cycle.
[0030]
The control device 4 controls the compressor 13, the expansion valve 15, the water supply pump 9, and the flow rate adjustment valve 10 based on an operation signal from an operation panel (not shown) and temperature information from the water temperature sensor 11 and the feedwater temperature sensor 12. The heat pump unit 2 performs a boiling operation to store hot water for hot water supply in the hot water storage tank 1. Further, the boiling operation is performed by detecting the amount of hot water storage from temperature information of a plurality of water level thermistors (not shown) provided on the outer wall surface of the hot water storage tank 1 and performing the boiling operation when the temperature becomes equal to or less than a predetermined hot water storage amount. It is configured.
[0031]
Here, the configuration of the evaporating heat exchanger 16 which is a main part of the present invention will be described based on FIG. FIG. 2A is a configuration diagram showing the overall configuration of the evaporating heat exchanger 16, and FIG. 2B is an explanatory diagram showing the number of refrigerant passages in the evaporating heat exchanger 16.
[0032]
As shown in FIG. 2A, the evaporating heat exchanger 16 of the present embodiment has a plurality of heat transfer tubes 16b and 16c formed in a tube shape, and is connected to the outer periphery of the heat transfer tubes 16b and 16c and is connected to an atmospheric heat exchanger. This is a fin-and-tube heat exchanger composed of a plurality of fin members 16e that exchange heat with the heat transfer tubes 16b and 16c, and includes an inlet tube 16a on the upstream side of the heat transfer tubes 16b and 16c and an outlet tube 16d on the downstream side.
[0033]
In order to divide the flow of the refrigerant, the tubes 16a to 16d flow in two passes from the inlet pipe 16a to the downstream side of the refrigerant flow, and then pass four passes in the middle of the evaporating heat exchanger 16. And are formed so as to be joined at the outlet pipe 16d. Specifically, as shown in FIG. 2A and FIG. 2B, the inlet pipe 16a is formed so that the upstream end is joined to the expansion valve 15, and from the joined portion, from the downstream side of the refrigerant flow. A two-pass refrigerant passage is formed up to the downstream end joined to the heat transfer tube 16b. The two-pass heat transfer tube 16b is joined midway to a four-pass heat transfer tube 16c comprising a refrigerant passage, and is configured to join at the outlet tube 16d.
[0034]
Further, in the present embodiment, the tubes 16a to 16d are formed to have different thicknesses. That is, the inlet tube 16a formed in two passes, the heat transfer tube 16b formed in two passes, and the heat transfer tube 16c formed in four passes are made of copper tubes having the same diameter (for example, φ6.0 mm). And the thickness of the refrigerant on the inlet side is made thicker. Incidentally, the two-pass inlet tube 16a has a thickness of 1.5 mm, the two-pass heat transfer tube 16b has a wall thickness of 0.6 mm, and the four-pass heat transfer tube 16c has a wall thickness of 0.4 mm. It is formed to be thicker than the side. This is to increase the rigidity of the tube near the inlet side.
[0035]
Next, an operation of the heat pump unit 2 including the evaporating heat exchanger 16 having the above-described configuration will be described with reference to FIGS. First, when the heat pump unit 2 performs the boiling operation, in the refrigeration cycle when the temperature of the water supply in the hot water storage tank 1 flowing into the hot water supply heat exchanger 14 is low, for example, the operation state of the refrigeration cycle is as follows. As shown in FIG. 6B, in the operating state of the hot water temperature T2 indicated by the solid line in the figure, since the degree of dryness is high at the outlet side (point A2a) of the evaporating heat exchanger 16, the gas phase is changed at this position. Since the amount is large, the specific volume is high and the flow velocity of the refrigerant is high. In the present invention, the pressure loss is not increased since the pressure loss is reduced by increasing the number of refrigerant passages of the heat transfer tubes 16c and thereafter to four paths.
[0036]
However, immediately before the completion of boiling, the temperature of the feedwater flowing into the hot water supply heat exchanger 14 increases. At this time, when the operation state of the refrigeration cycle is the operation state of T3a indicated by a broken line in the figure, the degree of dryness is high at the inlet side (point A3a) of the evaporating heat exchanger 16, so that the expansion valve is generally provided at this position. Since the flow velocity of the depressurized refrigerant is increased by 15, the refrigerant flow noise is easily generated at this time. Therefore, in the present invention, the thickness of this portion is formed to be thick, so that the rigidity is increased and the propagation of the refrigerant flow noise to the outside is prevented.
[0037]
The thickness of the inlet pipe 16a into which the refrigerant flows is found by the study of the inventors, and specifically, is determined from a characteristic diagram showing the relationship between the flow noise of the refrigerant and the thickness shown in FIG. It is a thing. That is, as shown in FIG. 3, when the wall thickness complies with the pressure resistance limit (for example, the pipe diameter × about 5%), the noise value is 6 dB. By setting it to 0.5 mm (25% of the tube diameter), a sound insulation effect of Δ5 dB is obtained. This is to prevent the propagation to the outside by increasing the rigidity due to the thick wall even when the refrigerant flow noise is generated.
[0038]
In the present embodiment, the wall thickness is set to 1.5 mm (25% of the pipe diameter). However, the present invention is not limited to this. As shown in FIG. The flow noise of the refrigerant can be reduced by about 2 to 5 dB by setting it to 12% or more, more preferably 20% or more of the pipe diameter. Also, by forming the refrigerant inflow side of the heat transfer tubes 16b and 16c to be thick, a sound insulation effect can be obtained as in the case of the inlet tube 16a.
[0039]
According to the heat pump type hot water supply apparatus of the first embodiment having the above-described configuration, in this type of hot water supply apparatus, the hot water is heated immediately before the completion of the heating. The refrigerant having a high degree of dryness flows into the pipe 16a. Therefore, in the present invention, the thickness of the inlet pipe 16a is made thicker than that of the heat transfer pipes 16b and 16c, so that the rigidity of the inlet pipe 16a is increased and a sound insulation effect is obtained. Even if the refrigerant flow noise is generated, the refrigerant flow noise is not transmitted to the outside, and the refrigerant flow noise can be reduced.
[0040]
Further, the inventors have studied the relationship between the refrigerant flow noise and the wall thickness of the inlet pipe 5a, and as a result, it is possible to reduce the refrigerant flow noise by increasing the wall thickness with respect to the diameter of the inlet pipe 16a. I found out. That is, the flow noise of the refrigerant generated in the inlet pipe (16a) can be reduced by setting the thickness of the inlet pipe 16a to preferably 12% or more, more preferably 20% or more of the pipe diameter.
[0041]
Further, as with the inlet pipe 16a, the heat transfer pipes 16b and 16c are also sound-insulated by forming the wall near the coolant inlet to be thicker than the other portions than the heat transfer pipes 16b and 16c having the same thickness. By obtaining the effect, the refrigerant flow noise can be reduced.
[0042]
Further, by using carbon dioxide as the refrigerant, a supercritical heat pump cycle can be formed. According to this, hot water can be heated at a higher temperature (for example, about 80 to 90 ° C.) than a general heat pump cycle using a chlorofluorocarbon-based refrigerant, and the boiling operation can be performed even with high-temperature water. It becomes possible.
[0043]
(2nd Embodiment)
In the first embodiment described above, after the number of refrigerant passages flows in two passes from the inlet pipe 16a to the downstream side of the refrigerant flow, the refrigerant is distributed to four passes in the middle of the evaporating heat exchanger 16 and merged at the outlet pipe 16d. However, the present invention is not limited to this. After the number of refrigerant passages flows in four passes from the inlet pipe 16a to the downstream side of the refrigerant flow, the refrigerant is distributed to two passes in the middle of the evaporating heat exchanger 16 and merges at the outlet pipe 16d. May be formed.
[0044]
Specifically, as shown in FIG. 4A and FIG. 4B, the inlet pipe 16a is formed so that the upstream end is joined to the expansion valve 15, and from the joined portion from the downstream side of the refrigerant flow. A four-pass refrigerant passage is formed up to the downstream end joined to the heat transfer tube 16b. The four-pass heat transfer tube 16b is joined to the two-pass heat transfer tube 16c, which is composed of two-pass refrigerant passages, and joins the outlet tube 16d.
[0045]
As a result, the number of refrigerant passages in the inlet pipe 16a on the refrigerant inflow side and the heat transfer pipe 16b is increased from two to four, so that the flow velocity of the refrigerant can be greatly reduced. The source can be reduced.
[0046]
(Third embodiment)
In the above-described second embodiment, after the number of refrigerant passages flows in four passes from the inlet pipe 16a to the downstream side of the refrigerant flow, the refrigerant is distributed to two passes in the middle of the evaporating heat exchanger 16 and joined at the outlet pipe 16d. However, the present invention is not limited to this. After the number of refrigerant passages flows from the inlet pipe 16a to the downstream side of the refrigerant flow in four passes, the refrigerant is distributed to two passes in the middle of the evaporating heat exchanger 16, and then distributed to four passes. You may form so that it may join by the outlet pipe 16d.
[0047]
More specifically, as shown in FIGS. 5A and 5B, the inlet pipe 16a is formed such that the upstream end is joined to the expansion valve 15, and from the joined portion from the downstream side of the refrigerant flow. A four-pass refrigerant passage is formed up to the downstream end joined to the heat transfer tube 16b. The four-pass heat transfer tube 16b is divided into two passes on the way, and then joined to the heat transfer tube 16c composed of the refrigerant passages divided into four passes, and joined at the outlet pipe 16d. Thereby, the heat efficiency can be improved when the feedwater temperature is low (for example, at the time of T2) because the pressure loss also decreases on the downstream side of the refrigerant flow as compared with the second embodiment.
[0048]
(Other embodiments)
In the above embodiment, the present invention relates to a heat pump comprising a supercritical heat pump comprising a refrigerant functional component constituting a heat pump cycle of a compressor 13, a hot water supply heat exchanger 14, a pressure reducing means 15, an evaporation heat exchanger 16 and an accumulator 17. Although applied to the unit 2, the invention is not limited to this, and may be applied to hot water supply means constituting a general heat pump cycle.
[0049]
Note that the specific numerical values and the like shown in the present embodiment are merely examples, and the present invention is not limited to these.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an overall configuration of a heat pump water heater according to a first embodiment of the present invention.
FIG. 2A is a side view showing the entire configuration of the evaporating heat exchanger 16 in the first embodiment of the present invention, and FIG. 2B is an explanatory diagram illustrating the number of refrigerant passages that divide the flow of the refrigerant. .
FIG. 3 is a characteristic diagram showing a relationship between a noise value of a refrigerant flow noise and a pipe wall thickness in the first embodiment of the present invention.
FIG. 4A is a side view showing the entire configuration of the evaporating heat exchanger 16 in the second embodiment of the present invention, and FIG. 4B is an explanatory diagram illustrating the number of refrigerant passages that divide the flow of the refrigerant. .
FIG. 5A is a side view showing the entire configuration of the evaporating heat exchanger 16 according to the third embodiment of the present invention, and FIG. 5B is an explanatory diagram illustrating the number of refrigerant passages for dividing the flow of the refrigerant. .
6A is an explanatory diagram showing a temperature distribution in a height direction of a hot water storage tank, and FIG. 6B is a characteristic diagram showing an operation state of a refrigeration cycle when a refrigerant of carbon dioxide is used as a refrigerant.
[Explanation of symbols]
1. Hot water storage tank 2. Heat pump unit (hot water supply means)
13 Compressor 14 Hot water supply heat exchanger 15 Expansion valve (pressure reducing means)
16 heat exchanger for evaporation 16a inlet pipes 16b, 16c heat transfer pipe 16d outlet pipe

Claims (7)

A hot water storage tank (1) in which water is supplied from a water supply source to a water supply side and hot water for hot water supply is stored in the hot water storage side;
A compressor (13) for compressing the refrigerant, a hot water supply heat exchanger (14) for exchanging heat between high-pressure refrigerant discharged from the compressor (13) and water taken from the water supply side of the hot water storage tank (1); In a heat pump hot water supply device comprising: a pressure reducing means (15); and a hot water supply means (2) in which an evaporation heat exchanger (16) for absorbing atmospheric heat is connected in order by a refrigerant pipe.
The evaporating heat exchanger (16) has an inlet pipe (16a) into which the refrigerant decompressed by the decompression means (15) flows, and a plurality of fins that exchange heat with the atmosphere are joined to the outer periphery, and the refrigerant is contained inside. , And an outlet pipe (16d) through which the heat-absorbed refrigerant flows out. The inlet pipe (16a) has a thickness of the inlet pipe (16a) of the heat transfer pipe. A heat pump hot water supply device characterized by being formed thicker than (16b, 16c). The heat pump hot water supply apparatus according to claim 1, wherein the inlet pipe (16a) is formed such that a thickness of the inlet pipe (16a) is preferably 12% or more with respect to a pipe diameter. The heat pump hot water supply apparatus according to claim 1, wherein the inlet pipe (16a) is formed so that a wall thickness of the inlet pipe (16a) is more preferably 20% or more with respect to a pipe diameter. A hot water storage tank (1) in which water is supplied from a water supply source to a water supply side and hot water for hot water supply is stored in the hot water storage side;
A compressor (13) for compressing the refrigerant, a hot water supply heat exchanger (14) for exchanging heat between high-pressure refrigerant discharged from the compressor (13) and water taken from the water supply side of the hot water storage tank (1); In a heat pump hot water supply device comprising: a pressure reducing means (15); and a hot water supply means (2) in which an evaporation heat exchanger (16) for absorbing atmospheric heat is connected in order by a refrigerant pipe.
The evaporating heat exchanger (16) has an inlet pipe (16a) into which the refrigerant decompressed by the decompression means (15) flows, and a plurality of fins that exchange heat with the atmosphere are joined to the outer periphery, and the refrigerant is contained inside. , And an outlet pipe (16d) through which the heat-absorbed refrigerant flows out. The heat transfer pipes (16b, 16c) are among the heat transfer pipes (16b, 16c). A heat pump hot water supply apparatus characterized in that the thickness of the heat transfer tubes (16b, 16c) is thicker in the vicinity of the inlet than in other portions. In the evaporating heat exchanger (16), a plurality of refrigerant passages are formed by the inlet pipe (16a), the heat transfer pipes (16b, 16c), and the outlet pipe (16d) to divide the flow of the refrigerant. 5. The refrigerant passage according to claim 1, wherein the number of the refrigerant passages decreases from the inlet pipe to a downstream side of the refrigerant flow. 6. Heat pump water heater. In the evaporating heat exchanger (16), a plurality of refrigerant passages are formed by the inlet pipe (16a), the heat transfer pipes (16b, 16c), and the outlet pipe (16d) to divide the flow of the refrigerant. The number of the refrigerant passages is sequentially reduced from the inlet pipe (16a) downstream of the inlet pipe (16a), and the number of the refrigerant passages is increased again. The heat pump hot water supply apparatus according to any one of the above. The heat pump hot water supply apparatus according to any one of claims 1 to 6, wherein the hot water supply means (2) uses carbon dioxide as a refrigerant.

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