JP5495844B2 - Water heater and drainage method for water heater - Google Patents

Description

  The present invention relates to a hot water supply device and a drainage method for the hot water supply device.

  In a hot water supply facility such as a golf course, the hot water supply device may be stopped for a long period of time, such as a period when it is not open in winter. At that time, the hot water supply device is often turned off. For this reason, when the temperature of the atmosphere decreases, if water remains in the water heat exchanger (more specifically, in the water heat transfer pipe of the water heat exchanger), the water in the water heat exchanger freezes. It can expand and destroy the water heat exchanger.

  Therefore, in the conventional hot water supply apparatus, as a draining method from the inside of the water heat exchanger, for example, “liquid temperature sensor 16 for detecting the liquid temperature in the liquid circuit W3 and liquid in the liquid inflow path W1 to the heat exchanger 3” The on-off valve 13 and the intake valve 14 for intermittently inflowing the refrigerant, the three-way valve 15 for switching the fluid flow path to the drainage side in the liquid outflow path W2 from the heat exchanger 3, and the circulation pump 6 are provided. When the liquid temperature detected by the liquid temperature sensor 16 becomes lower than a predetermined value while the operation is stopped, the flow of liquid is blocked by the on-off valve 13, the three-way valve 15 is switched to the drain side, and the circulation pump 6 Is operated for a predetermined condition, and the liquid in the heat exchanger 3 is discharged "(see Patent Document 1).

JP 2003-240343 A (Summary, FIG. 1)

  However, in the conventional drainage method from the water heat exchanger, if an air flow path is formed in the upper part of the water side heat transfer tube of the water heat exchanger, water remains in the water side heat transfer tube. There was a problem that it could not be removed. In particular, in the case of a water heat exchanger in which the water-side heat transfer tubes are arranged in a circular shape in order to improve the heat exchange efficiency, the water-side heat transfer tubes are horizontal or the water-side heat transfer tubes There may be an inverse gradient. For this reason, the water heat exchanger in which the water-side heat transfer tubes are arranged in the shape of a spider tends to cause a problem that the water cannot be removed while remaining in the water pipe as described above. In the case of a heat exchanger in which heat exchange units with water-side heat transfer tubes arranged in a circular shape are stacked in parallel, water may remain only in the water-side heat transfer tubes of some heat exchange units, Occurrence of the problem that the water remains in the water pipe as described above and cannot be removed is more remarkable.

  This invention is made | formed in order to solve the above subjects, and it aims at obtaining the hot-water supply apparatus and the drainage method of a hot-water supply apparatus which can drain more reliably than before from a water heat exchanger.

A hot water supply apparatus according to the present invention is a refrigerant in which a compressor, a refrigerant side heat transfer tube of a first heat exchanger that heats water with a refrigerant, a decompression device, and a second heat exchanger that acts as an evaporator are connected by piping. A hot water supply apparatus having a circulation circuit, provided on one of an inlet side and an outlet side of a water-side heat transfer tube of a first heat exchanger, and in a opened state, a first opening / closing device communicating with the outside, to drive the compressor in a state where the switchgear open the causes refrigerant to flow to the refrigerant side heat transfer tube, and a control device for performing water-discharge operation of discharging the accumulated water inside the water side heat transfer tube, the control device Is for controlling the rotational speed of the compressor and the opening of the decompression device so that a refrigerant of 100 ° C. or higher flows into the refrigerant-side heat transfer tube during the drainage operation. Rotation speed of the compressor so that the pressure of the refrigerant discharged from the compressor is within the limit range Controlling, when the pressure exceeds the limit range is characterized in that to start again temporarily stop the compressor.

Moreover, the drainage method of the hot water supply apparatus according to the present invention includes a compressor, a refrigerant heat transfer tube of a first heat exchanger that heats water with a refrigerant, a decompression device, and a second heat exchanger that functions as an evaporator. A drainage method for a hot water supply apparatus having a refrigerant circulation circuit connected to a pipe and a control device for controlling the rotational speed of the compressor and the opening of the decompression device, wherein the water side heat transfer tube of the first heat exchanger A first opening / closing device provided on one of the inlet side or the outlet side is opened, a first opening step for communicating the water side heat transfer tube and the outside, and after the first opening step, the compressor is driven to generate a refrigerant. A drainage operation step for circulating the refrigerant through the side heat transfer tube and discharging the water accumulated in the water side heat transfer tube, and the control device allows the refrigerant at 100 ° C. or higher to flow through the refrigerant side heat transfer tube during the drainage operation step. The number of rotations of the compressor and the opening of the decompression device are controlled so as to flow into the The device controls the rotation speed of the compressor so that the pressure of the refrigerant discharged from the compressor is within the limit range during drainage operation, and temporarily stops the compressor when the pressure exceeds the limit range. And restarting again .

  In the present invention, by circulating the refrigerant through the refrigerant side heat transfer tube of the first heat exchanger (water heat exchanger), water staying in the water side heat transfer tube of the first heat exchanger evaporates, The pressure in the water side heat exchanger tube of 1 heat exchanger rises. And by this pressure rise, the vapor | steam and water in the water side heat exchanger tube of a 1st heat exchanger are discharged | emitted from a 1st switchgear. For this reason, the water which stayed in the water side heat exchanger tube of the 1st heat exchanger can be discharged more certainly than before.

It is a block diagram which shows the circuit structure of the hot water supply apparatus which concerns on embodiment of this invention. 1 is an external perspective view of a hot water supply apparatus according to an embodiment of the present invention. It is a disassembled perspective view of the hot water supply apparatus which concerns on embodiment of this invention. It is a top view which shows the machine room of the hot water supply apparatus which concerns on embodiment of this invention. It is a perspective view which shows the water heat exchanger which concerns on this invention. It is a figure which shows the heat exchanger tube coil of the water heat exchanger which concerns on this invention. It is a top view which shows an example of the switchgear concerning embodiment of this invention. It is a figure which shows the stopper of the opening / closing apparatus shown in FIG. It is explanatory drawing which shows the drainage effect of the drainage driving | running which concerns on embodiment of this invention. It is a figure which shows an example of the switchgear concerning embodiment of this invention.

Embodiment.
FIG. 1 is a configuration diagram showing a circuit configuration of a hot water supply apparatus according to an embodiment of the present invention. As shown in FIG. 1, a hot water supply device K includes a compressor 4, a water heat exchanger 3 that produces heat by heat exchange between water and a refrigerant, a decompression device 6 such as an expansion valve, and air exchange between the air and refrigerant. The air heat exchanger 7 and the water pump 22 are provided. And the refrigerant | coolant side heat exchanger tube 30, the decompression device 6, and the air heat exchanger 7 of the compressor 4, the water heat exchanger 3 are connected by piping, and the refrigerant | coolant circulation circuit 60 through which a refrigerant | coolant circulates is comprised. The refrigerant circulation circuit 60 includes a refrigerant temperature sensor 61 that detects the temperature of the refrigerant discharged from the compressor 4 and a refrigerant pressure sensor that detects the pressure of the refrigerant discharged from the compressor. 62 is provided. Further, a fan 10 that supplies air to the air heat exchanger 7 and a motor 11 that drives the fan 10 are provided in the vicinity of the air heat exchanger 7. The details of the refrigerant side heat transfer tube 30 will be described later.

  In the hot water supply apparatus K according to the present embodiment, the water pump 22 and the water-side heat transfer pipe 29 of the water heat exchanger 3 are connected by piping, and a water circulation circuit 70 is also configured. For example, a hot water storage tank (not shown) is connected to the water circulation circuit 70. In the water circulation circuit 70, an opening / closing device 73 is provided in an inlet side pipe 71 connected to the water inlet of the water side heat transfer pipe 29 of the water heat exchanger 3. In the present embodiment, for example, a manual three-way valve is used as the opening / closing device 73. That is, by opening the opening / closing device 73, the water-side heat transfer tube 29 of the water heat exchanger 3 communicates with the outside through the opening / closing device 73. In the water circulation circuit 70, an opening / closing device 80 </ b> A is provided in the outlet side pipe 72 connected to the water outlet of the water side heat transfer pipe 29 of the water heat exchanger 3. That is, by opening the opening / closing device 80A, the water-side heat transfer tube 29 of the water heat exchanger 3 is in communication with the outside via the opening / closing device 80A. The details of the water-side heat transfer tube 29 and the opening / closing device 80A will be described later.

  Here, one of the switchgear 73 or the switchgear 80A corresponds to the first switchgear in the present invention. Further, the other of the opening / closing device 73 or the opening / closing device 80A corresponds to the second opening / closing device of the present invention.

  Moreover, the control apparatus 1 is provided in the hot water supply apparatus K which concerns on this Embodiment. The control device 1 controls the rotational speed of the compressor 4, the opening degree of the decompression device 6, the rotational speed of the motor 11 connected to the fan 10, and the like based on the detection values of the refrigerant temperature sensor 61 and the refrigerant pressure sensor 62. To do.

The hot water supply device K having such a circuit configuration has the following configuration.
FIG. 2 is an external perspective view of the hot water supply apparatus according to the embodiment of the present invention. FIG. 3 is an exploded perspective view of the hot water supply apparatus. FIG. 4 is a plan view showing a machine room of the hot water supply apparatus.

  The front panel 42, the fingered 43 and the upper panel 44 are disposed in the front part of the base 41, the side panel 45 and the side panel 46 are provided on both sides of the base 41, and the rear panel 49 and the rear upper panel are provided on the back part of the base 41. 47 is deployed. A fan guard 48 is installed in an upper surface opening surrounded by the upper panel 44, the side panel 45, the side panel 46 and the rear upper panel 47. And the air heat exchanger 7 is arrange | positioned so that the air path formed of the side panels 45 and 46, the bellmouth 50, and the machine room partition plate 51 may be crossed. A fan 10 and a motor 11 are arranged above the air heat exchanger 7. Further, in the machine room partitioned from the outside environment by the machine room partition plate 51, the front panel 42 and the rear panel 49 in the lower part of the casing, the compressor 4, the pressure reducing device 6, the water heat exchanger 3, the water pump 22, A pipe group to be connected, a control box 23, and the like are provided. The control device 1 is accommodated in the control box 23.

Moreover, the water heat exchanger 3 of the hot water supply device K is configured as follows.
FIG. 5 is a perspective view showing a water heat exchanger according to the present invention. FIG. 6 is a view showing a heat transfer tube coil of the water heat exchanger, FIG. 6 (a) is a perspective view of the heat transfer tube coil, and FIG. 6 (b) is an AA view of FIG. 6 (a). A cross-sectional view is shown.

  As shown in FIG. 5, the water heat exchanger 3 is configured by stacking a plurality of heat exchange units in parallel. In the present embodiment, five heat exchange units 3 a to 3 e are stacked in parallel to constitute the water heat exchanger 3. In these heat exchange units 3a to 3e, the heat transfer tube coils 24 are arranged in a round shape so as to have a substantially rectangular shape in plan view. Moreover, these heat exchange units 3a-3e are comprised so that the heat exchanger tube coil 24 arrange | positioned at the inner peripheral side may be higher than the heat exchanger tube coil 24 arrange | positioned at the outer peripheral side. . Therefore, each of the heat exchange units 3a to 3e is disposed such that the heat transfer tube coil 24 is horizontal or the heat transfer tube coil 24 has a gradient (tilt) in a state where the water heat exchanger 3 is installed. There is a place to be done. By configuring the water heat exchanger 3 by arranging the heat transfer tube coils 24 in a circular shape, it is possible to reduce the installation space of the water heat exchanger 3 while maintaining the heat exchange efficiency of the water heat exchanger 3. Become.

  The heat transfer tube coil 24 constituting these heat exchange units 3a to 3e has a structure as shown in FIG. That is, the heat transfer tube coil 24 twists and winds three refrigerant-side heat transfer tubes 30 (refrigerant-side heat transfer tubes 30 a to 30 c) around the water-side heat transfer tube 29, and the refrigerant-side heat transfer tubes 30 a to 30 c around the water-side heat transfer tube 29. It is fixed and formed. Moreover, the direction of the water which flows through the water side heat exchanger tube 29 and the direction of the water which flows through the refrigerant | coolant side heat exchanger tubes 30a-30c are reverse. That is, the heat transfer tube coil 24 is configured to increase the heat transfer area and perform heat exchange by using water and refrigerant as opposed flows.

  As shown in FIG. 5, the heat exchange units 3 a to 3 e are connected in parallel to constitute the water heat exchanger 3. More specifically, the water inlets of the water-side heat transfer tubes 29 of the heat exchange units 3a to 3e are connected to the water inlet header 26 via connection pipes. The water outlets of the water side heat transfer tubes 29 of the heat exchange units 3a to 3e are connected to the water outlet header 25 via connection pipes. The refrigerant inlets of the refrigerant side heat transfer tubes 30 (refrigerant side heat transfer tubes 30a to 30c) of the heat exchange units 3a to 3e are connected to the refrigerant inlet header 27 via connection pipes. Refrigerant outlets of the refrigerant side heat transfer tubes 30 (refrigerant side heat transfer tubes 30a to 30c) of the heat exchange units 3a to 3e are connected to the refrigerant outlet header 28 via connection pipes.

  That is, the end of the inlet side pipe 71 shown in FIG. 1 is a water inlet header 26 and a connection pipe that connects the water inlet header 26 and the water side heat transfer pipe 29. Moreover, the edge part of the exit side piping 72 shown in FIG. 1 becomes connection piping which connects the water exit header 25 and this water exit header 25 and the water side heat exchanger tube 29. As shown in FIG. The opening / closing device 80A is provided in a connection pipe that connects the water outlet header 25 and the water-side heat transfer tube 29 of the heat exchange unit 3a disposed at the top. The heat exchange units 3a to 3e according to the present embodiment are formed such that the uppermost portion serves as a water outlet and the lowermost portion serves as a water inlet. For this reason, the switchgear 80 </ b> A is disposed at a height higher than the highest position of the heat transfer tube coil 24 (water-side heat transfer tube 29) constituting the water heat exchanger 3. The opening / closing device 73 is provided in the water inlet header 26 (not shown), for example. In the present embodiment, the opening / closing device 73 is provided in the water inlet header 26 at a position lower than the opening / closing device 80A.

The position where the opening / closing device 80A is provided is not limited to the position shown in FIG. For example, the water outlet header 25 may be provided with an opening / closing device 80A. For example, the water-side heat transfer tube 29 may be provided with an opening / closing device 80A. Further, for example, an opening / closing device 80A may be provided in a connection pipe that connects the water outlet header 25 and the water-side heat transfer pipe 29 other than the heat exchange unit 3a. In the present embodiment, such a vicinity of the water outlet of the water side heat transfer tube 29 is referred to as an outlet side of the water side heat transfer tube 29. That is, the opening / closing device 80 </ b> A only needs to be provided on the outlet side of the water-side heat transfer tube 29.
Further, the position where the opening / closing device 73 is provided is not limited to the water inlet header 26. For example, the opening / closing device 73 may be provided in a connection pipe that connects the water outlet header 25 and the water-side heat transfer tubes 29 of the heat exchange units 3a to 3e. In the present embodiment, such a vicinity of the water outlet of the water side heat transfer tube 29 is referred to as an inlet side of the water side heat transfer tube 29. That is, the opening / closing device 73 only needs to be provided on the inlet side of the water-side heat transfer tube 29.

In the present embodiment, the opening / closing device 80A provided on the outlet side of the water-side heat transfer tube 29 is configured as follows.
FIG. 7 is a plan view showing an example of the switchgear according to the embodiment of the present invention. FIG. 8 is a view showing a stopper of the opening / closing device, FIG. 8 (a) shows a front view of the stopper, and FIG. 8 (b) shows a side view of the stopper. In FIG. 7, a connection pipe that connects the water outlet header 25 and the water side heat transfer pipe 29 of the heat exchange unit 3 a arranged at the top is shown as an outlet side pipe 72.

  In this embodiment, as shown in FIG. 7, the outlet side pipe 72 is cut into an outlet side pipe 72a and an outlet side pipe 72b, and an opening / closing device 80A is provided between the outlet side pipe 72a and the outlet side pipe 72b. ing. The opening / closing device 80A includes a removal pipe 81, an O-ring 82, and a stopper 83. The removal pipe 81 has, for example, a substantially cylindrical shape, and flanges 81a are formed at both ends. The diameter of the inner peripheral portion of the removal pipe 81 is formed to be slightly larger than the outer diameters of the ends of the outlet side pipe 72a and the outlet side pipe 72b. The O-ring 82 is provided in a groove formed at the end of the outlet side pipe 72a and the outlet side pipe 72b. By removing the ends of the outlet side pipe 72a and the outlet side pipe 72b and inserting the pipe 81, the outlet side pipe 72a and the outlet side pipe 72b and the removal pipe 81 are sealed by the O-ring 82.

  The ends of the outlet side pipe 72 a and the removal pipe 81 and the outlet side pipe 72 b and the end of the removal pipe 81 are fixed by a stopper 83. As shown in FIG. 8, the stopper 83 is obtained, for example, by processing a plate member into a sheet metal. The stopper 83 includes a grip portion 84 that grips the outer peripheral portions of the outlet side pipe 72 a and the outlet side pipe 72 b (more specifically, the outer peripheral portion in a range not inserted into the removal pipe 81), and the outer peripheral portion of the removal pipe 81. A grip portion 85 that grips (more specifically, an outer peripheral portion other than the flange 81a) is formed. In addition, an insertion port 86 that is a through-hole is formed between the grip portion 84 and the grip portion 85. By gripping the outer periphery of the outlet side pipe 72a and the outlet side pipe 72b with the gripping portion 84 and gripping the outer periphery of the removal pipe 81 with the gripping portion 85, the end side and the outlet side of the outlet side piping 72a and the removal pipe 81 The ends of the pipe 72b and the removal pipe 81 are fixed by a stopper 83. At this time, the flange 81 a of the removal pipe 81 is inserted into the insertion port 86.

<Description of operation>
The water heater K configured as described above operates as follows.

(Operation during hot water operation)
First, the operation of the hot water supply apparatus K during normal hot water supply operation will be described.
During a normal hot water supply operation, the high-temperature and high-pressure refrigerant compressed by the compressor 4 flows into the refrigerant-side heat transfer tube 30 of the water heat exchanger 3. And this refrigerant is cooled by heating the water which flows through the water side heat exchanger tube 29 of the water heat exchanger 3. The refrigerant cooled by the water heat exchanger 3 is decompressed by the decompression device 6 and flows into the air heat exchanger 7 acting as an evaporator. The refrigerant flowing into the air heat exchanger 7 absorbs heat from the atmosphere sent from the fan 10 and flows into the compressor 4. During a normal hot water supply operation, the temperature of the refrigerant flowing into the water heat exchanger 3 is controlled to a temperature that does not boil water.

(Operation during drainage operation)
Then, operation | movement of the hot water supply apparatus K at the time of drainage operation is demonstrated.
In a hot water supply facility such as a golf course, the hot water supply device may be stopped for a long period of time, such as a period when it is not open in winter. At that time, the hot water supply device K is often turned off. Therefore, the control device 1 of the hot water supply device K is provided with a function of performing a drain operation operation in order to extract water from the water side heat transfer tube 29 of the water heat exchanger 3 before the hot water supply device K is stopped for a long period of time. . The control device 1 performs the drainage operation when a signal for commanding the drainage operation is input from the outside (for example, by an operation panel or the like).

  When water is extracted from the water-side heat transfer tube 29 of the water heat exchanger 3, the opening / closing device 73 and the opening / closing device 80A are first opened (set to the open state). To open the opening / closing device 80A, the stopper 83 is removed from the end of the outlet side pipe 72a and the removal pipe 81 and from the end of the outlet side pipe 72b and the removal pipe 81. Then, by opening the ends of the outlet side pipe 72a and the outlet side pipe 72b from the removal pipe 81, the opening / closing device 80A is opened. The opening order of the opening / closing device 73 and the opening / closing device 80A is arbitrary. Of course, the opening / closing device 73 and the opening / closing device 80A may be opened simultaneously.

  As described above, the opening / closing device 80 </ b> A is provided at a position higher than the opening / closing device 73. Therefore, the opening / closing device 80A functions as an intake port, and the opening / closing device 73 functions as a drain port. Therefore, air enters the water-side heat transfer tube 29 of the water heat exchanger 3 from the opening / closing device 80 </ b> A serving as an intake port. Then, according to the law of universal gravitation, the air entered from the opening / closing device 80A serving as the intake port pushes out the water in the water-side heat transfer tube 29, and the water in the water-side heat transfer tube 29 is discharged from the opening / closing device 73 serving as the drain port. (Hereinafter, this drainage process is referred to as a drainage process by its own weight). In the present embodiment, the opening / closing device 80 </ b> A is arranged at a height equal to or higher than the highest position of the water-side heat transfer tube 29 of the water heat exchanger 3. For this reason, in the drainage process by its own weight, the water in the water-side heat transfer tube 29 can be quickly drained.

  However, if only the drainage process by its own weight causes an air flow path in the upper part of the water-side heat transfer tube 29 of the water heat exchanger 3, the water remains in the water-side heat transfer tube 29 and cannot be completely removed. End up. In particular, when the water-side heat transfer tube 29 is arranged in the shape of a bowl like the water heat exchanger 3 according to the present embodiment, the water-side heat transfer tube 29 becomes horizontal or the water-side heat transfer tube 29 is water when draining. The direction of flow may be reversed. Further, in the case of a water heat exchanger in which a plurality of heat exchange units are stacked like the water heat exchanger 3 according to the present embodiment, the water-side heat transfer tube 29 is horizontal depending on the assembled state of each heat exchange unit. Or the water-side heat transfer tube 29 may have a gradient opposite to the direction of water flow during drainage. For this reason, the heat exchanger such as the water heat exchanger 3 according to the present embodiment is more likely to have a problem that water cannot be completely removed while remaining in the water-side heat transfer tube 29.

Therefore, in the present embodiment, the water retained in the water-side heat transfer tube 29 is discharged by performing a drainage operation after the drainage process by its own weight.
When a signal for commanding the drainage operation is input from the outside (for example, through an operation panel or the like), the control device 1 starts the compressor with the opening / closing device 73 and the opening / closing device 80A opened. Then, the refrigerant is circulated through the refrigerant circulation circuit 60.
In addition, the flow in the refrigerant circuit 60 is the same direction as in the hot water supply operation.

  In the drainage operation, the control device 1 controls the rotation speed of the compressor 4 so that the pressure of the refrigerant discharged from the compressor 4 (detected value of the refrigerant pressure sensor 62) is within the limit range. The refrigerant pressure discharged from the compressor 4 is controlled within the restricted range by the refrigerant side heat transfer pipe 30 of the water heat exchanger 3, the internal parts of the compressor 4, other piping in the refrigerant circulation circuit 60, and the like. This is to prevent damage. This control is also performed during the hot water supply operation. However, in the drainage operation, the number of revolutions of the compressor 1 is usually kept lower than the normal hot water supply operation because water is not supplied. When the pressure of the refrigerant discharged from the compressor 4 exceeds the limit range, the compressor 4 may be temporarily stopped and the compressor may be started again.

  Further, the control device 1 controls the opening degree of the decompression device 6 so that the temperature of the refrigerant discharged from the compressor 4 (detected value of the refrigerant temperature sensor 61) is equal to or higher than a predetermined temperature. That is, the control device 1 controls the opening degree of the decompression device 6 so that the refrigerant having a predetermined temperature or higher flows through the refrigerant side heat transfer tube 30 of the water heat exchanger 3. In the present embodiment, the control device 1 controls the opening degree of the decompression device 6 so that the temperature of the refrigerant discharged from the compressor 4 (detected value of the refrigerant temperature sensor 61) is 100 ° C. or higher. . More specifically, the control device 1 controls the opening degree of the decompression device 6 so that the temperature of the refrigerant discharged from the compressor 4 (detected value of the refrigerant temperature sensor 61) is about 120 ° C. This is because the water staying in the water-side heat transfer tube 29 of the water heat exchanger 3 is evaporated as soon as possible. Note that the decompression device 6 may be controlled so that the temperature of the refrigerant discharged from the compressor 4 (detected value of the refrigerant temperature sensor 61) is equal to or lower than a certain upper limit value. This is because if the temperature of the refrigerant discharged from the compressor 4 is too high, the compressor 4 may break down.

By performing the drainage operation in this manner, water staying in the water-side heat transfer tube 29 of the water heat exchanger 3 starts to evaporate. And the pressure in the water side heat exchanger tube 29 of the water heat exchanger 3 rises with this water evaporation. And by this pressure rise, the vapor | steam and water in the water side heat exchanger tube 29 of the water heat exchanger 3 are discharged | emitted from the switchgear 73 and the switchgear 80A.
In this embodiment, both the opening and closing device 73 and the opening and closing device 80A are opened and the drainage operation is performed. However, if one of the opening and closing device 73 or the opening and closing device 80A is open, the present invention can be implemented. This is because steam and water in the water-side heat transfer tube 29 of the water heat exchanger 3 are discharged from the open switchgear.

FIG. 9 shows the drainage effect when the drainage operation is performed.
The drainage effect was confirmed using the water heat exchanger 3 capable of storing 0.8 L of water in the water-side heat transfer tube 29. When the drainage process by its own weight was performed, 0.25 L to 0.5 L of water remained in the water side heat transfer tube 29 of the water heat exchanger 3. This value depends on the arrangement conditions of the water-side heat transfer tube 29 and the like (the length of the horizontal portion of the water-side heat transfer tube 29, the location where the water-side heat transfer tube 29 has a reverse gradient to the direction of water flow during drainage) It depends on whether or not there is.
On the other hand, after the drainage operation was performed, only 0.25 L to 0.26 L of water remained in the water-side heat transfer tube 29 of the water heat exchanger 3. That is, by performing the drainage operation, the water in the water-side heat transfer tube 29 that could not be discharged in the drainage process by its own weight can be discharged.

  As described above, the hot water supply device K configured as described above is configured to discharge water in the water-side heat transfer pipe 29 of the water heat exchanger 3 by opening at least one of the switchgear 73 or the switchgear 80A and performing a drainage operation. Can be reliably discharged.

  Further, by opening both the opening / closing device 73 and the opening / closing device 80A, a drainage process by its own weight can be performed. For this reason, the drainage operation in the water-side heat transfer tube 29 of the water heat exchanger 3 can be performed quickly.

  In the drainage operation, the temperature of the refrigerant discharged from the compressor 4 (the temperature of the refrigerant flowing through the refrigerant-side heat transfer tube 30 of the water heat exchanger 3) is set to 100 ° C. or higher, so that the water in the water heat exchanger 3 is The water in the side heat transfer tube 29 evaporates quickly, and the drainage work in the drainage operation can be performed quickly.

  Moreover, by providing the switchgear 80A at a height higher than the highest position of the water-side heat transfer tube 29 of the water heat exchanger 3, the drainage work can be quickly performed in the drainage process by its own weight.

Note that the opening / closing device 73 and the opening / closing device 80A described in this embodiment are merely examples. For example, the opening / closing device 80 </ b> A may be used as the opening / closing device 73. For example, the opening / closing device 80A may be a manual three-way valve. For example, the opening / closing device 73 and the opening / closing device 80A may be configured as shown in FIG.
10A and 10B are diagrams showing another example of the switchgear according to the embodiment of the present invention. FIG. 10A is a plan view of the switchgear and FIG. 10B is an exploded perspective view of the switchgear. The figure is shown. FIG. 10 shows a case where the opening / closing device 80B is installed at the position of the opening / closing device 80A. FIG. 10 shows only one end side (exit side pipe 72a side) of the opening / closing device 80B. The other end side (exit side pipe 72b side) of the switchgear 80B has the same shape as the one end side (exit side pipe 72a side) of the switchgear 80B.

  As shown in FIG. 10, the outlet side pipe 72a is formed with a groove provided with an O-ring 82 and a flange 72c from the end side. The outer diameter of the flange 72 c is substantially the same as the outer diameter of the flange 81 a formed on the removal pipe 81. In addition, a grip portion 88 is formed on the stopper 87. The inner diameter of the grip portion 88 is substantially the same as the outer diameter of the flange 72c and the flange 81a. Further, the width of the gripping portion 88 is substantially the same as “the width of the flange 72c + the width of the flange 81a”. The outlet side pipe 72a is removed and inserted into the pipe 81 so that the flange 72c and the flange 81a are in contact with each other. Then, by gripping the flange 72 c and the flange 81 a with the grip portion 88, the outlet side pipe 72 a and the removal pipe 81 are fixed.

  Of course, an automatic opening / closing device (such as a three-way valve) may be used for the opening / closing device 73 and the opening / closing device 80A. That is, the automatic opening / closing device 73 and the opening / closing device 80A may be electrically connected to the control device 1, and the control device 1 may open and close the opening / closing device 73 and the opening / closing device 80A. The drainage process by its own weight can also be performed by inputting a signal to the control device 1 from the outside.

  DESCRIPTION OF SYMBOLS 1 Control apparatus, 3 Water heat exchanger, 3a-3e Heat exchange unit, 4 Compressor, 6 Depressurization apparatus, 7 Air heat exchanger, 10 Fan, 11 Motor, 22 Water pump, 23 Control box, 24 Heat transfer tube coil, 25 Water outlet header, 26 Water inlet header, 27 Refrigerant inlet header, 28 Refrigerant outlet header, 29 Water side heat transfer tube, 30 (30a-30c) Refrigerant side heat transfer tube, 41 Base, 42 Front panel, 43 Fingered, 44 Upper part Panel, 45 Side panel, 46 Side panel, 47 Rear upper panel, 48 Fan guard, 49 Rear panel, 50 Bell mouth, 51 Machine room partition plate, 60 Refrigerant circulation circuit, 61 Refrigerant temperature sensor, 62 Refrigerant pressure sensor, 70 Water circulation Circuit, 71 Inlet side piping, 72 (72a, 72b) Outlet side piping, 72c Franc 73, opening / closing device, 80A, 80B opening / closing device, 81 removal piping, 81a flange, 82 O-ring, 83 stopper, 84 gripping portion, 85 gripping portion, 86 insertion port, 87 stopper, 88 gripping portion, K hot water supply device.

Claims (6)

A hot water supply apparatus having a refrigerant circulation circuit in which a compressor, a refrigerant side heat transfer tube of a first heat exchanger that heats water with a refrigerant, a decompression device, and a second heat exchanger that functions as an evaporator are connected by piping. And
A first opening / closing device provided on one of the inlet side or the outlet side of the water-side heat transfer tube of the first heat exchanger and in communication with the outside in an open state;
A control device that performs a drain operation that drives the compressor with the first opening and closing device open, causes the refrigerant to flow through the refrigerant side heat transfer tube, and discharges the water retained in the water side heat transfer tube. When,
Equipped with a,
The control device controls the rotation speed of the compressor and the opening of the pressure reducing device so that a refrigerant of 100 ° C. or higher flows into the refrigerant side heat transfer tube during the drainage operation,
The control device controls the number of revolutions of the compressor so that the pressure of the refrigerant discharged from the compressor is within a limit range during the drainage operation, and the pressure exceeds the limit range. Is a hot water supply apparatus, wherein the compressor is temporarily stopped and then restarted .   The second opening / closing device that communicates with the outside in the open state is provided on the other of the inlet side and the outlet side of the water-side heat transfer tube of the first heat exchanger. The hot water supply device described in 1. In the first heat exchanger, the water-side heat transfer tube is arranged in a circular shape so that the height changes from the inlet side to the outlet side, and a horizontal portion is formed in the middle of the inlet side and the outlet side. Has been
The switchgear provided on the higher side of the first switchgear and the second switchgear is provided at a position that is higher than the highest point of the water-side heat transfer tube. The hot water supply device according to claim 2. A refrigerant circulation circuit in which a compressor, a refrigerant side heat transfer tube of a first heat exchanger that heats water with a refrigerant, a decompression device, and a second heat exchanger acting as an evaporator are connected by piping;
A control device for controlling the rotational speed of the compressor and the opening of the decompression device;
A method for draining a hot water supply apparatus comprising:
A first opening step of opening a first opening / closing device provided on one of the inlet side and the outlet side of the water side heat transfer tube of the first heat exchanger, and communicating the water side heat transfer tube with the outside;
After the first opening step, the compressor is driven to circulate the refrigerant through the refrigerant side heat transfer tube, and the drainage operation step of discharging the water staying inside the water side heat transfer tube;
Equipped with a,
The control device controls the rotation speed of the compressor and the opening of the pressure reducing device so that a refrigerant of 100 ° C. or higher flows into the refrigerant side heat transfer tube during the drainage operation,
The control device controls the number of revolutions of the compressor so that the pressure of the refrigerant discharged from the compressor is within a limit range during the drainage operation, and the pressure exceeds the limit range. Is a method of draining a hot water supply apparatus, wherein the compressor is stopped once and then restarted . On the other side of the inlet side or outlet side of the water side heat transfer tube of the first heat exchanger, a second opening / closing device communicating with the outside is provided in an open state,
The method for draining a hot water supply apparatus according to claim 4 , further comprising a second opening step of opening the second opening / closing device before the drainage operation step. In the first heat exchanger, the water-side heat transfer tube is arranged in a circular shape so that the height changes from the inlet side to the outlet side, and a horizontal portion is formed in the middle of the inlet side and the outlet side. Has been
The switchgear provided on the higher side of the first switchgear and the second switchgear is provided at a position that is higher than the highest point of the water-side heat transfer tube. The method for draining a hot water supply apparatus according to claim 5 .

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