tank

Abstract

To provide a technology capable of suppressing breakage of thermal stratification formed in a tank.SOLUTION: A tank according to the present invention includes: a top plate part spreading centering around a tank axis along a vertical direction; a peripheral wall part; a bottom plate part; an input port to which an inflow pipe is connected; an output port to which an outflow pipe is connected; an outgoing port to which an outgoing pipe is connected; a return port to which a return pipe is connected; and a joint pipe to be arranged to the return port. The output port is arranged in the vicinity of the tank axis on the top plate part. The return port is provided at a position eccentric relative to the tank axis on the top plate part. The joint pipe includes: a pipe body into which heat carrier returned from the return pipe flows; a discharge port provided by penetrating a part of an outer peripheral surface of the pipe body; and a bottom wall provided on a lower side than the discharge port in an axial direction of the pipe body. The heat carrier flowing in the pipe body collides with the bottom wall, thereby changes its direction, and guided to the discharge port. An opening direction of the discharge port is directed to the tank axis.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a tank. [Background technology]

[0002] Patent Document 1 discloses a tank for storing a heat medium, the tank having a supply pipe through which the heat medium flows from the bottom of the tank to a heating device, a return pipe through which the heat medium flows from the heating device to the top of the tank, an inlet pipe through which the heat medium flows into the bottom of the tank, and an outlet pipe through which the heat medium flows out from the top of the tank, all connected to one another. The tank includes a top plate extending around a tank axis along a vertical direction, a peripheral wall connected to the entire periphery of the top plate and extending below the top plate, a bottom plate connected to the entire periphery of the lower peripheral edge of the peripheral wall and closing the bottom of the peripheral wall, an inlet to which the inlet pipe is connected, an outlet to which the outlet pipe is connected, a supply port to which the supply pipe is connected, a return port to which the return pipe is connected, and a coupling pipe provided at the return port for connecting the return pipe to the return port. The outlet and return port are integrated and are both located on the tank axis in the top plate. The joint pipe includes a pipe body into which the heat transfer medium returned from the return pipe flows, a discharge port provided inside the top plate by penetrating a portion of the outer circumferential surface of the pipe body, and a bottom wall provided below the discharge port in the axial direction of the pipe body. The heat transfer medium flowing through the pipe body changes direction when it collides with the bottom wall and is guided to the discharge port. The discharge port opens radially outward over substantially the entire circumference of the tank axis. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-197982 Summary of the Invention [Problem to be solved by the invention]

[0004] In a tank such as that described in Patent Document 1, the heat transfer medium returned from the return pipe and discharged from the discharge port may collide with the inner surface of the peripheral wall, change direction, and flow toward the bottom of the tank. If the heat transfer medium returned from the return pipe flows toward the bottom of the tank, it may disrupt the temperature stratification (a state in which a layer of high-temperature heat transfer medium is stacked on top of a layer of low-temperature heat transfer medium) formed inside the tank. This specification provides a technology that can prevent the disruption of the temperature stratification formed inside the tank. [Means for solving the problem]

[0005] The tank disclosed in this specification is a tank for storing a heat medium, and includes a supply pipe through which the heat medium flows from the bottom of the tank to a heating device, a return pipe through which the heat medium flows from the heating device to the top of the tank, an inlet pipe through which the heat medium flows into the bottom of the tank, and an outlet pipe through which the heat medium flows out from the top of the tank. The tank includes a top plate extending around a tank axis along a vertical direction, a peripheral wall connected to the entire periphery of the top plate and extending below the top plate, a bottom plate connected to the entire periphery of the lower peripheral edge of the peripheral wall and closing the lower side of the peripheral wall, an inlet to which the inlet pipe is connected, an outlet to which the outlet pipe is connected, a supply port to which the supply pipe is connected, a return port to which the return pipe is connected, and a coupling pipe provided at the return port for connecting the return pipe to the return port. The outlet is provided in the top plate near the tank axis. The return port is provided at a position eccentric to the tank axis on the top plate. The joint pipe includes a pipe body into which the heat transfer medium returned from the return pipe flows, a discharge port provided inside the top plate by penetrating a portion of the outer circumferential surface of the pipe body, and a bottom wall provided below the discharge port in the axial direction of the pipe body. The heat transfer medium flowing through the pipe body collides with the bottom wall, changes direction, and is guided to the discharge port. The opening direction of the discharge port is oriented toward the tank axis.

[0006] According to the above configuration, the joint pipe is positioned eccentrically with respect to the tank axis, and the opening direction of the discharge port is oriented toward the tank axis. Therefore, the heat transfer medium returned from the return pipe is discharged inside the tank away from the peripheral wall. This prevents the heat transfer medium returned from the return pipe from colliding with the inner surface of the peripheral wall. According to the above configuration, the temperature stratification formed inside the tank can be prevented from being broken down.

[0007] In one or more embodiments, the opening direction is inclined upward relative to the horizontal.

[0008] For example, if the opening direction of the discharge port is inclined downward relative to the horizontal, the heat transfer medium returned from the return pipe will be less likely to accumulate in the upper part of the tank, which may disrupt the temperature stratification formed inside the tank. In contrast, with the above configuration, the heat transfer medium returned from the return pipe will be more likely to accumulate in the upper part of the tank, preventing the temperature stratification formed inside the tank from being disrupted.

[0009] In one or more embodiments, the discharge port includes a plurality of slit openings, each of which extends perpendicular to the axial direction when viewed from a direction opposite to the opening direction of the discharge port, and which are arranged parallel to one another along the axial direction.

[0010] For example, if the discharge port has only one opening, the flow of the heat medium discharged from the discharge port may be disturbed depending on the amount of heat medium returned from the return pipe. In contrast, with the above configuration, the heat medium discharged from the discharge port is rectified as it passes through multiple slit openings. This makes it possible to prevent the flow of the heat medium discharged from the discharge port from being disturbed.

[0011] In one or more embodiments, the top plate portion is provided with a shielding plate arranged to block the space between the discharge port and the outflow port.

[0012] In a tank, low-temperature heat transfer medium that has accumulated in the return pipe may be returned to the return port while still at a low temperature. In this case, if the heat transfer medium discharged from the discharge port reaches the vicinity of the outlet and flows out of the outlet as is, there is a possibility that the supply temperature of the heat transfer medium (for example, the hot water temperature of a water heater) may fluctuate. In contrast, with the above configuration, the shielding plate prevents the heat transfer medium discharged from the discharge port from reaching the vicinity of the outlet. Therefore, when the low-temperature heat transfer medium is returned to the return port, fluctuations in the supply temperature of the heat transfer medium can be suppressed. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram schematically illustrating a configuration of a hot water supply system 2 according to an embodiment. [Figure 2] 1 is an overall view of a tank 30 according to an embodiment, seen from the left side. [Figure 3] FIG. 2 is an overall perspective view of a joint pipe 316 according to the embodiment. [Figure 4] FIG. 10 is a view of a joint pipe 316 according to the embodiment, viewed from above. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] 10 is a view of the joint pipe 316 according to the embodiment, viewed from a direction opposite to the opening direction of the discharge port 334. FIG. [Figure 7] 3 is a cross-sectional view of the internal structure of the tank 30 according to the embodiment, as seen from the left. FIG. [Figure 8] FIG. 8 is a partially enlarged cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] 3 is a view of the top plate portion 302 of the tank 30 according to the embodiment as seen from below. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] (Example) As shown in FIG. 1, the hot water supply system 2 according to this embodiment includes an HP (heat pump) unit 4, a tank unit 6, and a burner unit 8.

[0015] The HP unit 4 is a heat source that absorbs heat from outside air to heat water. The HP unit 4 includes a compressor 10, a condenser 12, an expansion valve 14, and an evaporator 16. The compressor 10 pressurizes a refrigerant (e.g., a fluorocarbon-based refrigerant) to a high temperature and high pressure. The condenser 12 cools the refrigerant by heat exchange with water that flows in through an HP feed pipe 26 and flows out through an HP return pipe 28. The expansion valve 14 decompresses the refrigerant to a low temperature and low pressure. The evaporator 16 heats the refrigerant by heat exchange with outside air. The HP unit 4 circulates the refrigerant through the compressor 10, condenser 12, expansion valve 14, and evaporator 16 in this order, thereby absorbing heat from outside air in the evaporator 16 and heating water in the condenser 12. The HP feed pipe 26 is equipped with a circulation pump 18 that flows water toward the condenser 12 and a feed thermistor 20 that detects the temperature of the water flowing through the HP feed pipe 26. A return thermistor 22 is attached to the HP return pipe 28 to detect the temperature of the water flowing through the HP return pipe 28. The HP unit 4 further includes an outside air temperature thermistor 23 that detects the outside air temperature, and an HP controller 24 that controls the operation of each component of the HP unit 4.

[0016] The tank unit 6 includes a tank 30, a mixing valve 32, and a bypass control valve 34. The tank 30 is a sealed container covered with thermal insulation and stores water. In this embodiment, the capacity of the tank 30 is, for example, 100 liters. The HP supply pipe 26 is connected to the bottom of the tank 30, and the HP return pipe 28 is connected to the top of the tank 30. When the circulation pump 18 of the HP unit 4 is driven, water is sucked from the bottom of the tank 30 and sent to the condenser 12. The water heated in the condenser 12 and heated to a high temperature is returned to the tank 30 from the top. When the water heated by the HP unit 4 flows into the tank 30, a temperature stratification is formed inside the tank 30, with a layer of high-temperature water stacked on top of a layer of low-temperature water. The tank 30 is equipped with a hot water storage thermistor 36 that detects the temperature of the upper water and an intermediate thermistor 38 that detects the temperature of the intermediate water.

[0017] Tap water is supplied to the tank unit 6 via a water supply pipe 40. A pressure reducing valve 42 that reduces the water supply pressure and a water inlet thermistor 44 that detects the water supply temperature are attached to the water supply pipe 40. The water supply pipe 40 branches into a tank water supply pipe 46 that communicates with the lower part of the tank 30 and a tank bypass pipe 48 that communicates with the mixing valve 32. Check valves 50 and 52 are attached to the tank water supply pipe 46 and the tank bypass pipe 48, respectively. A water-side water volume sensor 54 that detects the flow rate of tap water flowing into the mixing valve 32 is attached to the tank bypass pipe 48. The upper part of the tank 30 and the mixing valve 32 are connected via a tank hot water outlet pipe 56. A check valve 58 and a hot water volume sensor 60 that detects the flow rate of water from the tank 30 that flows into the mixing valve 32 are attached to the tank hot water outlet pipe 56.

[0018] The mixing valve 32 mixes tap water flowing in from the tank bypass pipe 48 with water from the tank 30 flowing in from the tank hot water outlet pipe 56, and sends the mixed water to the first hot water supply pipe 62. The mixing valve 32 is driven by a stepping motor, and adjusts the opening degree on the tank bypass pipe 48 side (opening degree on the water side) and the opening degree on the tank hot water outlet pipe 56 side (opening degree on the hot water side). A mixing thermistor 64 that detects the temperature of the water sent out from the mixing valve 32 is attached to the first hot water supply pipe 62.

[0019] Hot water is supplied from tank unit 6 to hot water supply locations such as a kitchen, shower, and faucet via second hot water supply pipe 66. A hot water supply outlet thermistor 68 that detects the temperature of water supplied to the hot water supply location (hereinafter also referred to as "hot water temperature") and a check valve 70 are attached to second hot water supply pipe 66. First hot water supply pipe 62 and second hot water supply pipe 66 are connected by a hot water supply bypass pipe 72. A bypass control valve 34 is attached to hot water supply bypass pipe 72.

[0020] The tank unit 6 further includes a tank controller 74 and a remote control 76 capable of communicating with the tank controller 74. The tank controller 74 controls the operation of each component of the tank unit 6. The remote control 76 accepts various operational inputs from the user via switches, buttons, etc. The remote control 76 also notifies the user of various information related to the settings and operation of the hot water supply system 2 by display and audio.

[0021] The burner unit 8 includes a burner 80, a heat exchanger 82, a bypass servo 84, a water volume servo 86, and a water filling valve 88. The burner 80 is a heat source that heats water flowing through the heat exchanger 82 by burning gas. Water flows into the heat exchanger 82 from the first hot water supply pipe 62 of the tank unit 6 via a burner supply pipe 90. The water that passes through the heat exchanger 82 flows out to the second hot water supply pipe 66 of the tank unit 6 via a burner return pipe 92. A water volume servo 86 that adjusts the flow rate of water flowing into the heat exchanger 82 is attached to the burner supply pipe 90. The burner supply pipe 90 and the burner return pipe 92 are connected via a burner bypass pipe 94. A bypass servo 84 is attached to the connection between the burner supply pipe 90 and the burner bypass pipe 94. The bypass servo 84 adjusts the flow rate of water flowing from the burner supply pipe 90 to the burner bypass pipe 94. A burner hot water thermistor 96 is attached to the burner return pipe 92, which detects the temperature of the water flowing out of the heat exchanger 82. A water filling pipe 98 branches off from the burner return pipe 92. A water filling valve 88 is attached to the water filling pipe 98. Water is filled from the burner unit 8 into the bathtub, which is the hot water supply point, via the water filling pipe 98. The burner unit 8 further includes a burner controller 100, which controls the operation of each component of the burner unit 8.

[0022] The HP controller 24 and the tank controller 74 can communicate with each other. The tank controller 74 and the burner controller 100 can also communicate with each other. Therefore, the HP controller 24, the tank controller 74, and the burner controller 100 cooperate to perform control, allowing the hot water supply system 2 to perform various operations such as boiling operation and hot water supply operation. Hereinafter, the HP controller 24, the tank controller 74, and the burner controller 100 will be collectively referred to simply as the controllers.

[0023] The main operations of the hot water supply system 2 will be described below.

[0024] (Boiling operation) In the boiling operation, the hot water supply system 2 drives the HP unit 4 to boil the water in the tank 30. The timing to start the boiling operation can be set from various perspectives. For example, the controller may determine the start timing of the boiling operation based on the hot water supply performance up to the previous day so that the boiling of the water in the tank 30 ends just before a time when a large demand for hot water is expected. Alternatively, the user may instruct the controller to boil the water in the tank 30 via the remote control 76, which causes the controller to start the boiling operation.

[0025] When the boiling operation is started, the controller drives the compressor 10 to circulate the refrigerant through the compressor 10, condenser 12, expansion valve 14, and evaporator 16 in that order, and drives the circulation pump 18 to circulate water between the tank 30 and the condenser 12. As a result, water sucked out from the bottom of the tank 30 is heated in the condenser 12 to a predetermined boiling temperature (for example, 45°C) and returned to the top of the tank 30. When all the water in the tank 30 has been replaced with water heated to the boiling temperature, the controller ends the boiling operation.

[0026] (Hot water operation) In the hot water supply operation, water at the set hot water supply temperature is supplied to the hot water supply location. In the hot water supply system 2 of this embodiment, the hot water supply operation starts when the water volume (hot water volume) obtained by adding up the water volume detected by the water-side water volume sensor 54 and the water volume detected by the hot water-side water volume sensor 60 reaches a predetermined value or more.

[0027] When the hot water supply operation starts, the controller determines whether or not the tank 30 has run out of hot water. In this embodiment, the controller determines that the tank 30 has run out of hot water when the temperature detected by the hot water storage thermistor 36 falls below the hot water supply setting temperature.

[0028] If the tank 30 is not out of hot water, the controller prohibits the combustion operation of the burner 80. The controller also adjusts the opening of the mixing valve 32 so that the temperature detected by the mixing thermistor 64 is the hot water supply set temperature. In this case, high-temperature water supplied from the top of the tank 30 and low-temperature tap water supplied from the water supply pipe 40 are mixed in the mixing valve 32 to reach the hot water supply set temperature, and the mixed water is supplied to the hot water supply location.

[0029] If the tank 30 is out of hot water, the controller permits the combustion operation of the burner 80. The controller also adjusts the opening of the mixing valve 32 so that the temperature detected by the mixing thermistor 64 is lower than the hot water supply setting temperature by a predetermined temperature or more. In this case, high-temperature water supplied from the top of the tank 30 and low-temperature tap water supplied from the tank bypass pipe 48 are mixed in the mixing valve 32, then heated to the hot water supply setting temperature by the burner 80 and supplied to the hot water supply location.

[0030] When the water volume (hot water volume) obtained by adding together the water volume detected by the water side water volume sensor 54 and the water volume detected by the hot water side water volume sensor 60 falls below a predetermined value, the controller prohibits the combustion operation of the burner 80 and terminates the hot water supply operation.

[0031] (Configuration of Tank 30) As shown in FIG. 2 , the tank 30 includes a top plate 302, a peripheral wall 304, a bottom plate 306, a water inlet 308, a tap outlet 310, a feed port 312, a return port 314, a joint pipe 316, and three legs 318. The tap outlet 310 and the return port 314 are provided on the top plate 302. The water inlet 308 and the feed port 312 are provided on the bottom plate 306. The joint pipe 316 is provided on the return port 314. The three legs 318 are each fixed to the peripheral wall 304. The tank 30 is used with the three legs 318 placed on a mounting surface H. In this state, the three legs 318 support the tank 30. In this specification, the direction perpendicular to the mounting surface H is defined as the up-down direction. Furthermore, the direction parallel to the placement surface H, from the outlet 310 toward the return outlet 314, is defined as the forward direction, and the direction from the return outlet 314 toward the outlet 310 is defined as the rearward direction. The direction perpendicular to the up-down direction and the front-rear direction is defined as the left-right direction.

[0032] The peripheral wall 304 is formed in a cylindrical shape, and the top plate 302 and the bottom plate 306 are formed in a so-called dome shape. Hereinafter, the central axis of the peripheral wall 304 will be referred to as the "tank axis A." The tank axis A is an axis that extends in the vertical direction.

[0033] The top plate portion 302 widens around the tank axis A. As the top plate portion 302 widens radially outward from the tank axis A, it curves downward. The peripheral wall portion 304 is connected to the entire periphery of the periphery of the top plate portion 302 and extends below the top plate portion 302. The bottom plate portion 306 is connected to the entire periphery of the lower periphery of the peripheral wall portion 304 and closes the lower side of the peripheral wall portion 304. As the bottom plate portion 306 widens radially outward from the tank axis A, it curves upward.

[0034] The water inlet 308 is connected to the tank water supply pipe 46 (see Figure 1). The tap outlet 310 is connected to the tank tap outlet pipe 56 (see Figure 1). The HP supply pipe 26 (see Figure 1) is connected to the delivery port 312. The HP return pipe 28 (see Figure 1) is connected to the return port 314 via a joint pipe 316. The water inlet 308 and the tap outlet 310 are each located on the tank axis A. The water inlet 308 protrudes downward from the bottom of the bottom plate portion 306 along the tank axis A. The tap outlet 310 protrudes upward from the top of the top plate portion 302 along the tank axis A. The delivery port 312 and the return port 314 are each located eccentrically with respect to the tank axis A. The delivery port 312 protrudes normal to the outer surface of the bottom plate portion 306. The return port 314 protrudes in the normal direction of the outer surface of the top plate portion 302. The joint pipe 316 is inserted into the return port 314. In this embodiment, the joint pipe 316 is mechanically fixed to the return port 314 by a screw (not shown) or the like.

[0035] (Configuration of joint pipe 316) 3, the joint pipe 316 includes a pipe body 330 and a discharge port 334. The HP return pipe 28 (see FIG. 1) is connected to the joint pipe 316. This allows water returned from the HP return pipe 28 to flow into the pipe body 330.

[0036] As shown in Figure 5, water returned to the tank 30 from the HP return pipe 28 (see Figure 1) flows into the pipe main body 330 from the inlet section 338. The water that flows into the pipe main body 330 flows along the extension direction of the pipe main body 330. In this specification, the extension direction of the pipe main body 330 is also simply referred to as the "axial direction." Furthermore, the upper side in the axial direction is referred to as the "upper side," and the lower side in the axial direction is referred to as the "lower side."

[0037] As shown in FIG. 6 , the discharge port 334 has multiple slit openings 350 (12 slit openings 350 in this embodiment). The multiple slit openings 350 have the same shape. Each of the multiple slit openings 350 penetrates a portion of the outer circumferential surface of the pipe body 330 in a rectangular shape along a predetermined direction. Therefore, the discharge port 334 opens in the predetermined direction (this direction is also referred to as the “opening direction” in this specification). When the discharge port 334 is viewed from a direction opposite to the opening direction, each of the multiple slit openings 350 extends perpendicular to the axial direction and is arranged parallel to each other along the axial direction. The multiple slit openings 350 are also arranged in a lattice pattern. The multiple slit openings 350 are arranged in two rows, with six slit openings in each row along the axial direction. In this embodiment, each of the multiple slit openings 350 extends over an angular range of approximately 90° in the circumferential direction of the pipe body 330.

[0038] As shown in FIG. 5 , the joint pipe 316 further includes an eave portion 340 located above the discharge port 334 in the axial direction. The eave portion 340 extends toward the inside of the pipe main body 330 in the direction of the discharge port 334. The joint pipe 316 also includes a bottom wall 332 located below the discharge port 334 in the axial direction. The bottom wall 332 is connected to the entire circumference of the lower end of the pipe main body 330 and closes the pipe main body 330. The bottom wall 332 includes a first inclined portion 342 and a second inclined portion 344. The first inclined portion 342 and the second inclined portion 344 are connected to each other. The second inclined portion 344 extends approximately parallel to the eave portion 340 in the direction of the discharge port 334. A plurality of flat plate portions 346 (five flat plate portions 346 in this embodiment) are provided between the eave portion 340 and the second inclined portion 344. The flat plate portions 346 are arranged parallel to one another along the axial direction. Each of the flat plate portions 346 extends substantially parallel to the eave portion 340 and the second inclined portion 344 along the opening direction of the discharge port 334. The slit openings 350 are provided in gaps between the eave portion 340, the flat plate portions 346, and the second inclined portion 344.

[0039] As shown in Fig. 4, eave portion 340 has a generally semicircular plate shape when viewed from above. First inclined portion 342 is provided in a position that does not overlap eave portion 340 when viewed from above. On the other hand, second inclined portion 344 and multiple flat plate portions 346 (see Fig. 5) are provided in positions that overlap and are hidden by eave portion 340 when viewed from above. Although not shown, each of multiple flat plate portions 346 has a generally semicircular plate shape, similar to eave portion 340.

[0040] As shown in FIG. 5, a portion of the water flowing in the axial direction flows toward the first inclined portion 342 without colliding with the overhanging portion 340. The remaining portion of the water flowing in the axial direction collides with the overhanging portion 340, changes direction, and flows toward the first inclined portion 342. Therefore, below the overhanging portion 340, the water flows toward the first inclined portion 342. The water flowing toward the first inclined portion 342 then collides with the first inclined portion 342 and the second inclined portion 344, changes direction, and is guided toward the multiple slit openings 350 (discharge port 334). At this time, the water passing through the multiple slit openings 350 is rectified along the multiple slit openings 350. Therefore, the water rectified along the multiple slit openings 350 is discharged from the discharge port 334.

[0041] When viewing the coupling pipe 316 from a direction perpendicular to the axial direction, the opening direction of the outlet 334 is inclined from the bottom to the top. That is, the angle θ formed by the opening direction of the outlet 334 and the axial direction is smaller than 90°. The angle θ formed by the opening direction of the outlet 334 and the axial direction is in the range of 70°-80°, and in this embodiment is 75°. Therefore, water that flows into the pipe main body 330 is turned by approximately 105° before being discharged from the outlet 334.

[0042] As shown in FIG. 7 , the joint pipe 316 is inserted into the return port 314 along the protruding direction of the return port 314. Therefore, the extending direction of the pipe body 330 is substantially the same as the normal direction to the outer surface of the top plate 302. The entire discharge port 334 is disposed inside the top plate 302. The opening direction of the discharge port 334 is oriented toward the tank axis A. Therefore, water returned from the HP return pipe 28 is discharged away from the peripheral wall 304, which is closer to the joint pipe 316. The opening direction of the discharge port 334 is slanted upward relative to the horizontal direction and is oriented toward a position slightly offset upward from the top of the top plate 302. Therefore, the water discharged from the discharge port 334 flows between the joint pipe 316 and the top of the top plate 302, gradually approaching the inner surface of the top plate 302. This makes it easier for the water discharged from the discharge port 334 to accumulate at the top of the tank 30.

[0043] As shown in Figure 8, water discharged from the outlet 334 flows so as to spread radially outward from the pipe body 330 within the opening range of the outlet 334 (in this embodiment, within an angular range of approximately 180° in the circumferential direction of the pipe body 330). In this embodiment, the direction toward the radially outward direction of the pipe body 330 within the opening range of the outlet 334 is either horizontal or inclined upward from the horizontal. Therefore, in this embodiment, all of the water discharged from the outlet 334 flows horizontally or in a direction inclined upward from the horizontal. Therefore, the water discharged from the outlet 334 is piled up in the upper part of the tank 30.

[0044] (Configuration of the shielding plate 360) As shown in Fig. 9, the top plate 302 is provided with a shielding plate 360 ​​arranged to block the gap between the discharge port 334 and the tap port 310. The shielding plate 360 ​​includes a welded portion 362 welded to the top plate 302 and a shielding portion 364 connected to the welded portion 362. The shielding portion 364 has a substantially rectangular shape. The shielding plate 360 ​​is arranged so that the distance from the shielding portion 364 to the tap port 310 is shorter than the distance from the shielding portion 364 to the discharge port 334. As shown in Fig. 7, the shielding portion 364 extends substantially parallel to the extension direction of the pipe main body 330 and faces the discharge port 334.

[0045] For example, immediately after the start of the boiling operation, low-temperature water stagnating in the HP return pipe 28 (also referred to herein as "stagnant water in the pipe") is returned to the return port 314 without being heated and remains at a low temperature, and is then discharged from the discharge port 334. If the stagnant water in the pipe discharged from the discharge port 334 reaches the vicinity of the tap outlet 310, there is a possibility that low-temperature water will flow out from the tap outlet 310 when the hot water supply operation is subsequently started. If low-temperature water flows out from the tap outlet 310, there is a possibility that the hot water temperature will fluctuate. In contrast, in this embodiment, of the water returned from the HP return pipe 28 and discharged from the discharge port 334, the water flowing toward the tap outlet 310 collides with the shielding portion 364 and changes direction. Therefore, even if the stagnant water in the pipe is discharged from the discharge port 334, the stagnant water in the pipe does not immediately reach the vicinity of the tap outlet 310. As described above, in this embodiment, the shielding plate 360 ​​suppresses fluctuations in the hot water temperature.

[0046] (Variation) In the above embodiment, the tank 30 is provided in the hot water supply system 2 and is configured to store water. In another embodiment, the tank 30 may be provided in a combustion system other than the hot water supply system 2, and may store a heat medium other than water. For example, the combustion system may be a heating device that heats and circulates heating water (e.g., antifreeze), and the tank 30 may store antifreeze.

[0047] In the above embodiment, a configuration has been described in which the water in the tank 30 is circulated and heated by the HP unit 4. In another embodiment, the water in the tank 30 may be circulated and heated by a heating device other than the HP unit 4 (heat pump). For example, the water in the tank 30 may be circulated and heated by a burner device such as the burner unit 8, or the water in the tank 30 may be circulated and heated by a cogeneration system (a system that heats a heat medium using exhaust heat generated when electricity is generated).

[0048] In the above embodiment, the joint pipe 316 is mechanically fixed to the return port 314 by a screw (not shown) or the like. In another embodiment, the joint pipe 316 may be fixed to the return port 314 by a method other than a mechanical fixing method. For example, the joint pipe 316 may be welded to the return port 314.

[0049] In the above embodiment, the tapping outlet 310 is arranged on the tank axis A. In another embodiment, the tapping outlet 310 may be arranged at a position eccentric to the tank axis A. In this case, the tapping outlet 310 may be arranged so that the distance from the tapping outlet 310 to the tank axis A is smaller than the distance from the return port 314 to the tank axis A.

[0050] In the above embodiment, the description has been given of a configuration in which the return port 314 protrudes along the normal direction of the outer surface of the top plate portion 302. In another embodiment, the return port 314 may protrude in a direction different from the normal direction of the outer surface of the top plate portion 302 (for example, a direction slightly inclined with respect to the normal direction). In this case, the joint pipe 316 inserted into the return port 314 may be inserted along a direction different from the normal direction of the outer surface of the top plate portion 302.

[0051] In the above embodiment, the opening direction of the discharge port 334 is directed toward the tank axis A and is tilted upward relative to the horizontal direction. In another embodiment, the opening direction of the discharge port 334 does not have to be tilted upward relative to the horizontal direction.

[0052] In the above embodiment, the configuration has been described in which the discharge port 334 has a plurality of slit openings 350. In another embodiment, the discharge port 334 may not have a plurality of slit openings 350, but may have only one opening.

[0053] In the above embodiment, when the discharge outlet 334 is viewed from the direction opposite to the opening direction, the multiple slit openings 350 each extend perpendicular to the axial direction and are arranged parallel to one another along the axial direction. In another embodiment, when the discharge outlet 334 is viewed from the direction opposite to the opening direction, the multiple slit openings 350 do not have to extend perpendicular to the axial direction or be arranged parallel to one another along the axial direction. For example, when the discharge outlet 334 is viewed from the direction opposite to the opening direction, the multiple slit openings 350 may each extend along the axial direction or be arranged parallel to one another in a direction perpendicular to the axial direction.

[0054] In the above embodiment, a configuration has been described in which the joint pipe 316 includes the eaves portion 340 and the plurality of flat plate portions 346. In another embodiment, the joint pipe 316 does not have to include the eaves portion 340 and the plurality of flat plate portions 346. In other words, the joint pipe 316 does not have to include a member that protrudes inside the pipe main body 330, and the inner surface of the pipe main body 330 may have a smooth, approximately cylindrical shape.

[0055] In the above embodiment, the configuration has been described in which the bottom wall 332 is connected to the entire circumference of the lower end of the tube body 330 and closes the tube body 330. In another embodiment, the bottom wall 332 may not be connected to the entire circumference of the lower end of the tube body 330, and may not close the tube body 330. For example, the bottom wall 332 may be connected to a portion of the lower end of the tube body 330, and a gap may be provided between the bottom wall 332 and the tube body 330. In yet another embodiment, the bottom wall 332 may be provided with a through-hole that connects the inside and outside of the tube body 330.

[0056] In the above embodiment, the shielding plate 360 ​​is provided on the top panel 302. In another embodiment, the shielding plate 360 ​​does not have to be provided on the top panel 302.

[0057] In the above embodiment, the shape of the tank 30 (the shapes of the top plate portion 302, the peripheral wall portion 304, and the bottom plate portion 306), the shape of the plurality of slit openings 350, the shape of the shielding portion 364, etc. may be changed as appropriate. For example, the top plate portion 302 and the bottom plate portion 306 may have a disk shape expanding about the tank axis A instead of a dome shape. The plurality of slit openings 350 may have shapes different from one another. The shielding portion 364 may have a substantially elliptical shape instead of a substantially rectangular shape.

[0058] In the above embodiment, the opening range of the discharge port 334 may be changed as appropriate. For example, the opening range of the discharge port 334 may be an angular range of about 90° in the circumferential direction of the pipe main body 330.

[0059] (Correspondence) In this specification, water is an example of a heat transfer medium. The HP unit 4 is an example of a heating device. The HP supply pipe 26 is an example of a supply pipe. The HP return pipe 28 is an example of a return pipe. The tank water supply pipe 46 is an example of an inlet pipe. The tank hot water outlet pipe 56 is an example of an outlet pipe. The water supply port 308 is an example of an inlet. The hot water outlet 310 is an example of an outlet. "On the tank axis A" is an example of "near the tank axis." "Hot water temperature" is an example of "water supply temperature."

[0060] Although the embodiments have been described in detail above, they are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives alone has technical utility. [Explanation of symbols]

[0061] 2: Hot water system 4:HP unit 6: Tank unit 8: Burner unit 10: Compressor 12: Condenser 14: Expansion valve 16: Evaporator 18: Circulation pump 20: Forward thermistor 22: Return thermistor 23: Outdoor temperature thermistor 24:HP Controller 26:HP Outlet Pipe 28:HP return pipe 30: Tank 32: Mixing valve 34: Bypass control valve 36: Hot water storage thermistor 38: Intermediate thermistor 40: Water supply pipe 42: Pressure reducing valve 44: Water inlet thermistor 46: Tank water supply pipe 48: Tank bypass pipe 50: Check valve 52: Check valve 54: Water side water level sensor 56: Tank outlet pipe 58: Check valve 60: Hot water level sensor 62: First hot water pipe 64: Mixed thermistor 66: Second hot water pipe 68: Hot water outlet thermistor 70: Check valve 72: Hot water bypass pipe 74: Tank Controller 76: Remote control 80: Burner 82: Heat exchanger 84: Bypass servo 86: Water volume servo 88: Bath valve 90: Burner supply pipe 92: Burner return pipe 94: Burner bypass pipe 96: Burner hot water thermistor 98: Hot water pipe 100: Burner controller 302: Top plate 304: Peripheral wall part 306: Bottom plate part 308: Water supply port 310: Tap hole 312: Exit 314: Return entrance 316: Joint pipe 318: Legs 330: Pipe body 332: Bottom wall 334:Discharge port 338 :Inflow part 340: Eave 342: 1st slope part 344:Second slope part 346: Multiple flat sections 350: Multiple slit openings 360: Shielding plate 362: Welded parts 364: Shielding part A: Tank axis H: Placement surface

Claims

1. A tank for storing a heat medium, the tank being connected to a feed pipe through which the heat medium flows out from a lower part of the tank to a heating device, a return pipe through which the heat medium flows from the heating device to an upper part of the tank, an inlet pipe through which the heat medium flows into a lower part of the tank, and an outlet pipe through which the heat medium flows out from an upper part of the tank, The top plate extends from the center of the tank axis along the vertical direction, a peripheral wall portion connected to the entire periphery of the top plate portion and extending downward from the top plate portion; a bottom plate portion connected to the entire periphery of the lower peripheral edge portion of the peripheral wall portion and closing the lower side of the peripheral wall portion; an inlet to which the inlet pipe is connected; an outlet to which the outflow pipe is connected; an inlet port to which the inlet pipe is connected; a return port to which the return pipe is connected; a joint pipe provided at the return port for connecting the return pipe to the return port, The outlet is provided in the top plate portion near the tank axis, The return port is provided at a position eccentric to the tank axis on the top plate portion, The coupling pipe is a pipe body into which the heat transfer medium returned from the return pipe flows; a discharge port provided inside the top plate portion and penetrating a part of the outer circumferential surface of the pipe body; a bottom wall provided below the discharge port in the axial direction of the pipe body, The heat transfer medium flowing through the pipe body collides with the bottom wall, changes direction, and is guided to the discharge port, The opening direction of the discharge port is directed toward the tank axis, The discharge port is not disposed on a surface of the outer circumferential surface of the pipe body that faces in a direction from the tank axis toward the pipe body.

2. The tank of claim 1 , wherein the opening direction is inclined upward relative to the horizontal direction.

3. the discharge port has a plurality of slit openings, When the discharge port is viewed from a direction opposite to the opening direction, each of the plurality of slit openings is extending perpendicular to the axial direction, 3. The tank of claim 1 or 2, wherein the tanks are arranged parallel to each other along the axial direction.

4. 3. The tank according to claim 1, wherein the top plate is provided with a shielding plate arranged to block the space between the discharge port and the outflow port.

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