JP2012107785A - Hot water storage type water heater device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater device that can still prevent, even in a configuration of using the hot water in a hot water storage tank, decrease in an available amount of hot water due to the production of intermediate temperature water, as well as deterioration of the efficiency in heating.SOLUTION: The hot water storage type water heater device includes: a first hot water feeding pipe 3 connected to the upper part of the hot water storage tank 1; a second hot water feeding pipe 4 connected, in the vertical direction of the hot water storage tank 1, between the position where the first tapping pipe 3 is connected and the position where a water supply pipe 5 is connected; a heat utilization hot water feeding pipe 21 connected to the upper part of the hot water storage tank 1; a heat exchanger 20 connected to the heat utilization feeding pipe 21; a heat utilization return pipe 22 connected to the hot water storage tank 1 at a position higher, in the vertical direction of the hot water storage tank 1, than the position where the second hot water feeding pipe 4 is connected to the hot water storage tank; and a circulation unit 25 composed of the heat utilization hot water feeding pipe 21, the heat exchanger 20 and the heat utilization return pipe 22, and for circulating the hot water in a heat utilization circuit. The circulation unit 25 is connected at a position higher, in the vertical direction of the hot water storage tank 1, than the position where the heat utilization return pipe 22 is connected to the hot water storage tank 1.

Description

  The present invention relates to a hot water storage type hot water supply apparatus that stores water heated by a heat pump type heating means in a hot water storage tank.

  This type of hot water supply apparatus heats the water supplied from the bottom of the hot water tank to a high temperature by a heating means, and repeats a series of cycles to store it in the upper part of the hot water tank covered with a heat insulating material, thereby Or store hot water in a part. When the user uses hot water to supply hot water, the user mixes it with unheated water so as to obtain a predetermined temperature and use the hot water supply terminal.

  The operating efficiency of the heat pump heating means used here depends on the outside air temperature, the boiling temperature, and the incoming water temperature, which is the temperature of the water supplied to the heating means, and when the outside air temperature is high or the boiling temperature is low, Operation efficiency is improved when the incoming water temperature is low. The outside air temperature varies depending on the season and operation time, and in addition, the incoming water temperature also varies depending on the temperature state of the hot water tank.

  In particular, when using a terminal that uses the heat in the hot water tank such as a bath chase or a radiator, the hot water in the heat using terminal and the hot water in the hot water tank are exchanged with a heat exchanger. It is configured to return to. Originally, there is water at the bottom of the hot water tank at a temperature that is about the same as the water supply temperature. However, when the use of a heat terminal occurs, the hot water from the heat exchanger is mixed with the low water at the bottom. Therefore, intermediate temperature water having an intermediate temperature higher than the feed water temperature is generated in the lower part of the hot water tank. Since the medium-temperature water is supplied to the heating means at the time of boiling, the temperature of the incoming water rises and the efficiency is significantly reduced.

  Conventionally, in order to remove the medium temperature water generated by the heat utilization terminal, a second hot water outlet is provided at an intermediate position in the vertical direction of the hot water tank, and the hot water existing at the intermediate position is preferentially used (for example, , See Patent Document 1).

  FIG. 11 shows a conventional hot water supply apparatus described in Patent Document 1. As shown in FIG. As shown in FIG. 11, a hot water tank 1, a heating means 2 for heating the hot water in the hot water tank 1, a first outlet pipe 3 connected to the upper part of the hot water tank 1, and an intermediate portion of the hot water tank 1 Second hot water pipe 4 connected, first mixing valve 6 for mixing hot water from first hot water pipe 3 of hot water tank 1 and hot water from second hot water pipe 4, and second hot water pipe 4 is provided with an intermediate temperature detecting means 12 for detecting the hot water temperature in the hot water storage tank 1 at a position to which 4 is connected, and a hot water supply temperature setting means 30 for setting the hot water temperature, and the hot water temperature detected by the intermediate temperature detecting means 12 is the hot water temperature. The first mixing valve 6 is heated so that the hot water is discharged from the second hot water discharge pipe 4 if the hot water supply set temperature set by the setting means 30 is equal to or higher than the hot water supply set temperature. Switch the flow path.

  Moreover, the heat utilization terminal 23, the heat exchanger 20 for exchanging the heat of the hot water storage tank 1 and the heat in the heat utilization terminal 23, the heat utilization hot water discharge pipe 21 connected to the upper part of the hot water storage tank 1, and the heat exchanger 20 And a heat utilization return pipe 22 connected to the lower part of the hot water tank 1, a pump 25 for conveying hot water from the hot water tank 1 to the heat exchanger 20, and heat utilization for detecting the heat utilization temperature at the heat utilization terminal 23. The temperature detection means 24 and the heat use temperature setting means 31 for setting the use temperature at the heat use terminal 23 are provided, and when the heat use by the heat use terminal 23 occurs, the temperature detected by the heat use temperature detection means 24 The flow rate is controlled by controlling the pump 25 according to the temperature set by the heat utilization temperature setting means 31. The intermediate warm water returning from the heat utilization return pipe 22 enters from the lower part of the hot water storage tank 1, rises according to the use of hot water, and is used after being discharged from the second hot water discharge pipe 4.

JP 2003-240342 A

  However, when the connection position of the heat utilization return pipe 22 with the hot water storage tank 1 is lower than the connection position of the second hot water discharge pipe 4, the medium-temperature water generated by using the heat utilization terminal 23 cannot be sufficiently removed. , Can not prevent the deterioration of efficiency.

  Here, this operation will be described in detail with reference to FIG. First, FIG. 12 explains the temperature change caused by the hot water from the heat return pipe in the hot water storage tank 1 in the conventional configuration and the temperature change when hot water is generated. The horizontal axis represents temperature and the vertical axis represents hot water storage. The temperature distribution is shown by taking the height of the tank 1. Reference numeral 51 in FIG. 12A denotes an initial temperature distribution, and when hot water from the heat return pipe 22 flows into the bottom of the hot water tank 1 from that state, as shown in 52 of FIG. The temperature T1 of the low-temperature hot water at the bottom of 1 rises uniformly to T2 and intermediate hot water is generated.

  Thereafter, when hot water such as a shower is generated, as shown at 53 in FIG. Water flows in and the temperature returns to T1. However, although the lowest part is a low temperature, the medium temperature water shown by 54 beyond it remains unusable.

  Thereafter, since hot water is circulated in turn from the bottom of the hot water tank 1 to the heating means 2 to perform boiling at night, the medium temperature water that has been raised to T2 is sent to the heating means 2 and the efficiency is lowered. Therefore, in view of the temperature distribution change due to the return of hot water from the heat utilization return pipe 22, when the connection position of the heat utilization return pipe 22 is lower than the second hot water discharge pipe 4, the efficiency is sufficiently reduced. It can be seen that it cannot be prevented.

  The present invention solves the above-mentioned conventional problems, and in a configuration using hot water in a hot water storage tank, it can be used by suppressing a decrease in the amount of hot water available due to the generation of medium-temperature water and a decrease in efficiency at the time of boiling. It aims at providing the hot water supply apparatus excellent in property and energy saving property.

  In order to solve the conventional problems, a hot water storage type hot water supply apparatus of the present invention includes a hot water storage tank, a first hot water pipe connected to the upper part of the hot water tank, and a water supply pipe connected to the lower part of the hot water tank. And a second hot water pipe connected between a position where the first hot water pipe is connected and a position where the water supply pipe is connected in the vertical direction of the hot water tank, and an upper part of the hot water tank The heat utilization hot water pipe, the heat exchanger connected to the heat utilization hot water pipe, the heat exchanger and the hot water storage tank, and in the vertical direction of the hot water storage tank, the second hot water discharge pipe A heat utilization return pipe connected to the hot water storage tank at a position higher than the connection position of the hot water storage tank, the heat utilization hot water discharge pipe, the heat exchanger, and the heat utilization return pipe, Circulating means for circulating hot water, and the circulating means in the vertical direction of the hot water storage tank There are, and is characterized in that it is disposed in the hot water storage position above the connecting position of tank of the heat utilization return pipe.

  As a result, when hot water is used at the heat utilization terminal, the medium-temperature water generated by the hot water returning from the heat exchanger to the hot water tank can be used effectively through the second hot water outlet, and the hot water in the hot water tank When draining water, freezing damage can be prevented without generating residual water in the heat utilization circuit composed of the heat utilization hot water pipe, the heat exchanger, and the heat utilization return pipe.

  According to the present invention, in a configuration using hot water in a hot water storage tank, hot water supply excellent in usability and energy saving performance is suppressed by suppressing a decrease in the amount of available hot water due to the generation of medium-temperature water and a decrease in efficiency during boiling. Equipment can be provided.

Configuration diagram of hot water supply apparatus in Embodiment 1 of the present invention Control block diagram when the same hot water supply occurs Flow chart of control when hot water is generated The figure which shows the change of the temperature distribution in the same hot water tank Control block diagram when heat is used at the same heat-using terminal Flow chart of control when heat utilization occurs at the same heat utilization terminal (A) The figure showing the temperature distribution before the heat utilization at the same heat utilization terminal (b) The figure showing the temperature distribution immediately after the heat utilization at the same heat utilization terminal (c) At the same heat utilization terminal Figure showing the temperature distribution after hot water is used and hot water is generated (A) The figure which shows the mechanism in which a big temperature gradient generate | occur | produces when the temperature of the hot water storage tank is high in Embodiment 1 of this invention (b) Large temperature when the temperature of the hot water storage tank is low in Embodiment 1 of this invention Diagram showing how the gradient occurs The figure which shows the other connection structure of the mixing valve which can be considered in Embodiment 1 of this invention (A) The figure which shows the hot water supply temperature when the hot water temperature of the 1st hot water pipe from a hot water storage tank changes rapidly in Embodiment 1 of this invention (b) From the hot water storage tank in Embodiment 1 of this invention The figure which shows the hot-water supply temperature in case the hot-water temperature of a 2nd hot-water pipe changes rapidly. Configuration diagram of conventional hot water supply equipment (A) The figure which shows the temperature distribution before the heat utilization in a heat utilization terminal generate | occur | produces in the conventional hot water supply apparatus (b) The figure which shows the temperature distribution immediately after the heat utilization in a heat utilization terminal occurs in the conventional hot water supply apparatus (C) The figure which shows the temperature distribution after hot water supply generate | occur | produces after the heat utilization in a heat utilization terminal generate | occur | produced in the conventional hot water supply apparatus.

  1st invention WHEREIN: The hot water storage tank, the 1st hot water pipe connected to the upper part of the said hot water storage tank, the water supply pipe connected to the lower part of the said hot water storage tank, and the said 1st in the up-down direction of the said hot water storage tank A second hot water pipe connected between a position where the hot water pipe is connected and a position where the water supply pipe is connected; a heat-utilizing hot water pipe connected to an upper portion of the hot water storage tank; and the heat-utilizing hot water pipe. A heat exchanger connected to the heat exchanger, connected to the heat exchanger and the hot water storage tank, and at a position higher than a connection position of the hot water storage tank of the second hot water pipe in the vertical direction of the hot water storage tank. A circulation means for circulating hot water in a heat utilization circuit composed of a heat utilization return pipe connected to the tank, the heat utilization hot water pipe, the heat exchanger, and the heat utilization return pipe; In the vertical direction of the hot water tank, the means is a connecting position of the hot water tank of the heat return pipe. A hot water storage type hot water supply apparatus characterized by being arranged in or more positions.

  As a result, when hot water is used at the heat utilization terminal, the medium-temperature water generated by the hot water returning from the heat exchanger to the hot water tank can be used effectively through the second hot water outlet, and the hot water in the hot water tank When draining water, freezing damage can be prevented without generating residual water in the heat utilization circuit composed of the heat utilization hot water pipe, the heat exchanger, and the heat utilization return pipe.

  According to a second aspect of the present invention, there is provided a feed water branch pipe branched from the feed water pipe, a first mixing valve in which the second hot water pipe and the first hot water pipe are connected to an inlet side, and the first A tapping pipe joining pipe connected to the outlet side of the mixing valve, a second mixing valve in which the tapping pipe joining pipe and the feed water branch pipe are connected to the inlet side, and an outlet side of the second mixing valve And a connected mixed water pipe.

  As a result, the hot water generated by the hot water returning from the heat exchanger to the hot water tank is effectively utilized through the second hot water discharge pipe, so that the amount of heat of the hot water is effectively utilized and the boiling efficiency is improved. Since reduction can be prevented, there is an effect that good usability and high energy saving can be realized. Moreover, the hot water supply which is comparatively stable with respect to the rapid temperature change which generate | occur | produces in a hot water tank with the connection method which mixes the hot water from a hot water supply pipe after mixing the hot water of a 1st hot water pipe, and a 2nd hot water pipe. Supply of hot water at temperature is possible.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of a hot water supply apparatus according to the first embodiment of the present invention.

  In FIG. 1, a hot water supply apparatus includes a hot water tank 1, a heat pump device that is a heating means 2 for heating water in the hot water tank 1, a first hot water pipe 3 connected to the upper part of the hot water tank 1, and a hot water tank. 1 is connected between the water supply pipe 5 connected to the lower part of 1 and the position where the first hot water discharge pipe 3 and the water supply pipe 5 are connected, that is, in the height direction to the substantially central part of the trunk of the hot water tank 1. A first hot water pipe 4, a feed water branch pipe 10 branched from the feed water pipe 5, a first mixing valve 6 in which the first hot water pipe 3 and the second hot water pipe 4 are connected to the inlet side; A second mixing valve 7 connected to the outlet side of the first mixing valve 6 and a feed water junction pipe 8 and a feed water branch pipe 10 connected to the inlet side, and an outlet side of the second mixing valve 7 And a mixed water pipe 9 connected to.

  Furthermore, a hot water supply port 11 connected to the mixed water pipe 9, a medium temperature detection means 12 for detecting the hot water temperature flowing through the second hot water discharge pipe 4, and a combined temperature detection means for detecting the hot water temperature flowing through the hot water discharge pipe merging pipe 8. 13, a hot water supply temperature detection means 14 for detecting the temperature of hot water flowing through the mixed water pipe 9, a heat utilization hot water discharge pipe 21 connected to the upper part of the hot water storage tank 1, and a heat exchanger 20 connected to the heat utilization hot water supply pipe 21 Heat utilization connected between the upper part of the hot water storage tank 1 to which the first hot water discharge pipe 3 and the heat utilization hot water discharge pipe 21 are connected and the trunk portion of the hot water storage tank 1 to which the second hot water discharge pipe 4 is connected. The return pipe 22, the heat utilization terminal 23 connected to the heat exchanger 20, the pump 25 that is a circulation means for adjusting the amount of hot water flowing through the heat utilization return pipe 22, and the heat that detects the temperature of the hot water flowing through the heat utilization terminal 23 Use temperature detection means 24.

  In addition, the heat utilization hot water pipe 21, the heat exchanger 20 connected to the heat utilization hot water pipe 21, and the heat utilization return pipe 22 form a heat utilization circuit.

  And when the pump 25 drains the hot water in the hot water tank 1, in the vertical direction of the hot water tank 1, in order to prevent freezing damage without generating residual water in the heat utilization circuit, The hot water return pipe 22 is disposed between the hot water tank 1 connection position and the hot water discharge pipe 21 connection position of the hot water tank 1.

  That is, the heat utilization circuit is formed so that there is no pipe at a position lower than the connection position of the hot water storage tank 1 of the heat utilization return pipe 22, and the pump 25 is arranged in the heat utilization circuit, so that the hot water in the hot water tank 1 is When draining, hot water does not remain in the heat utilization circuit by its own weight, and freezing damage can be prevented.

Furthermore, the hot water supply temperature setting means 30 for setting the hot water supply temperature of the hot water supply port 11, the heat use temperature setting means 31 for setting the heat use temperature of the heat use terminal 23, the intermediate temperature detection means 12, the combined temperature detection means 13, and the hot water supply temperature. The first mixing valve 6 and the second mixing valve 7 are controlled based on the output of the detection means 14 and the setting of the hot water supply temperature setting means 30, and the outputs of the heat use temperature setting means 31 and the heat use temperature detection means 24, And a control device 33 having control means 32 for controlling the pump 25 based on the setting of the heat utilization temperature setting means 31.

  FIG. 2 is a block diagram of the control, and the first mixing valve 6 and the first mixing valve 6 are connected to each other based on the output of the intermediate temperature detecting means 12, the combined temperature detecting means 13, and the hot water temperature detecting means 14 and the setting of the hot water temperature setting means 30. It comprises control means 32 for controlling the two mixing valves 7.

  About the hot water supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  As a basic operation, the hot water tank 1 is filled with a lot of low-temperature water before boiling, and when the operation is started, the water in the hot water tank 1 is sent to the heat pump device 2 where it is heated and heated to hot water. Is returned to the hot water tank 1. As a result, hot water is stored in the hot water tank 1.

  When using hot water after boiling, the hot water in the hot water storage tank 1 discharged through the first hot water discharge pipe 3 and the second hot water discharge pipe 4 is mixed in the hot water discharge pipe joining pipe 8 mixed by the first mixing valve 6. The hot water and the water supplied from the water supply branch pipe 10 are mixed to the hot water supply set temperature by the second mixing valve 7 and supplied to the hot water supply port 11. Further, water corresponding to the amount of hot water used for hot water supply flows from the lower part of the hot water tank 1 through the water supply pipe 5.

  Here, the operation when using the hot water supply and the operation when using the heat utilization terminal will be described in detail with reference to FIGS. The hot water supply temperature is set as the hot water supply set temperature by the hot water supply temperature setting means 30, ts is the hot water supply set temperature of the hot water supply port 11, ts 2 is a temperature higher than the hot water supply set temperature, for example, + 5 ° C., and tm is the medium temperature detection means 12. The detected temperature. Further, te is a temperature detected by the heat use temperature detecting means 24, and ts3 is a temperature set by the heat use set temperature means.

  FIG. 3 is a flowchart of control when hot water is generated. When hot water supply is started, the magnitude relationship between tm and ts2 is determined (step 1), and when tm is higher than ts2, the first mixing valve 6 is set so that hot water is discharged only from the second hot water discharge pipe 4. Fully open to the second tapping pipe 4 side (step 2).

  When tm is equal to or less than ts2, the opening degree of the first mixing valve 6 is adjusted based on the hot water temperature detected by the merging temperature detecting means 13 so that the merging temperature detecting means 13 becomes ts2 (step 3). . Thereafter, the second mixing valve 7 mixes the hot water in the hot water discharge pipe joining pipe 8 and the water in the hot water supply branch pipe 10 so that the output from the hot water supply temperature detection means 14 becomes ts (step 4). Hot water adjusted to the set temperature ts is supplied from the hot water supply port 11 through the mixed water pipe 9.

  FIG. 4 is a diagram showing changes in the temperature distribution in the hot water tank 1. The horizontal axis indicates the temperature, and the vertical axis indicates the height of the hot water tank 1. The temperature distribution of 45 indicates that the upper end of the intermediate temperature layer, which is an intermediate temperature zone, is at the position where the second hot water pipe 4 is connected to the hot water tank 1. In some cases, that is, just before the hot water supply in the middle temperature zone is started. While the hot water is discharged from both the first hot water discharge pipe 3 and the second hot water discharge pipe 4, the intermediate temperature layer moves upward of the hot water storage tank 1 while being reduced.

  When the hot water temperature at the hot water joining pipe 8 when the hot water is discharged from both becomes ts or less, the hot water from the second hot water pipe 4 is stopped, and the intermediate temperature layer is moved as it is above the hot water tank 1. As a result, the size of the intermediate temperature layer is initially 15 f but is reduced to 15 g. 46 is a temperature distribution at the time when the intermediate temperature layer 15g passes through the connection position of the second hot water discharge pipe 4.

  FIG. 5 shows a block diagram of control when heat is used at the heat use terminal 23, and the control of the pump 25 is based on the output of the heat use temperature detecting means 24 and the setting of the heat use temperature setting means 31. It consists of the control means 32 which performs.

  FIG. 6 is a flowchart of control when heat is used at the heat use terminal 23. When the use at the heat utilization terminal 23 is started, the heat utilization temperature detection means 24 detects the temperature te of the heat utilization terminal 23 and compares te with the heat utilization terminal set temperature ts3 (step 5). When te is lower than ts3, driving of the pump is started (step 6), and when it is higher, driving of the pump is stopped (step 7).

  FIG. 7 explains the temperature change caused by the hot water from the heat return pipe in the hot water tank 1 and the temperature change when hot water is generated. The horizontal axis indicates the temperature, and the vertical axis indicates the hot water tank 1 height. The temperature distribution taken is shown. T1 is the feed water temperature, T3 is the temperature of the upper part of the hot water storage tank 1, and T2 is the temperature of the medium temperature water generated by the inflow of hot water from the heat utilization return pipe 22.

  Reference numeral 61 in FIG. 7A denotes an initial temperature distribution. When hot water from the heat utilization return pipe 22 flows into the upper part of the hot water tank 1 from that state, the temperature distribution as indicated by 62 in FIG. It becomes. Although T2 changes with the temperature which flows in from the heat | fever utilization return pipe | tube 22, and T3, the hot water below the position where the heat | fever utilization return pipe | tube 22 of the hot water storage tank 1 is connected is always medium temperature water.

  Thereafter, when hot water is generated, the second hot water discharge pipe 4 is connected to a position below the heat-use return pipe, so that the medium-temperature water generated by the heat-use return pipe 22 is preferentially used, The influence of the temperature distribution change by the utilization return pipe 22 can be removed.

  In addition, since the heat return pipe 22 is connected to the upper part of the hot water tank 1 and the temperature of the lower part of the hot water tank 1 is maintained at the feed water temperature T1, the medium temperature water circulates in the heating device at the time of boiling and the efficiency is increased. It will never drop.

  Next, in order to generate the hot water supply temperature ts, the first hot water discharge pipe 3, the second hot water discharge pipe 4, and the water supply pipe are connected by the connection configuration of the first mixing valve 6 and the second mixing valve 7 shown in FIG. The action at the time of mixing 5 hot water will be described.

  First, a phenomenon in which a large temperature gradient is partially generated in the hot water tank 1 when hot water returns from the heat utilization return pipe 22 to the hot water tank 1 will be described. FIG. 8 is a diagram for explaining this phenomenon. The temperature of the hot water tank 1 is shown in the horizontal axis direction, and the height of the hot water tank 1 is shown in the vertical axis.

  FIG. 8A shows a case where the temperature at the connection position between the heat utilization return pipe 22 and the hot water storage tank 1 is higher than the temperature of the hot water returning from the heat utilization return pipe 22, and a dotted line 81 indicates the heat at the heat utilization terminal 23. It is the temperature distribution of the hot water tank 1 just before the start of use.

  In this case, when the heat utilization is started, as indicated by the solid line 82, the hot water in the hot water storage tank 1 is mixed with the hot water in the heat utilization return pipe 22 and becomes a lower temperature hot water, so Medium temperature water is generated in the part. As heat utilization proceeds, as shown by the temperature distribution indicated by the solid line 83, the temperature of the medium-temperature water immediately below the connection position is lower and the area becomes larger, and a portion having a large temperature gradient is formed above the connection position. A state is formed.

  FIG. 8B shows a case where the temperature at the connection position between the heat utilization return pipe 22 and the hot water tank 1 is lower than the temperature of the hot water returning from the heat utilization return pipe 22, and the dotted line 84 indicates the heat at the heat utilization terminal 23. It is the temperature distribution of the hot water tank 1 just before the start of use.

In this case, when the heat utilization is started, as indicated by the solid line 85, the low temperature hot water in the hot water storage tank 1 is mixed with the hot water in the heat utilization return pipe 22 to become higher hot water. Medium temperature water is produced. As heat utilization progresses, as shown by the temperature distribution indicated by the solid line 86, the medium-temperature water immediately above the connection position has a higher temperature and a larger area, and a portion having a large temperature gradient is formed at the lower part of the connection position. A state is formed.

  The portion with the large temperature gradient formed as described above rises upward in the hot water tank 1 as hot water use progresses, or boiling occurs during the daytime, and its position in the hot water tank 1 is The hot water is supplied from the second hot water discharge pipe 4 by shifting downward.

  At that time, since the temperature gradient is large, the opening adjustment of the first mixing valve 6 and the second mixing valve 7 may not catch up with the temperature change, and the hot water may be supplied at a temperature lower than the hot water supply temperature.

  Next, it will be described that the fluctuation of temperature can be prevented by adopting the connection configuration (high temperature premixing) of the first mixing valve 6 and the second mixing valve 7 shown in FIG.

  Here, in addition to the mixing valve, as a conceivable connection configuration, as shown in FIG. 9, first, the hot water from the second hot water discharge pipe 4 and the water from the water supply branch pipe 10 are lower by a predetermined temperature than the hot water supply temperature. After mixing to temperature, the method of mixing with the hot water from the 1st tap pipe 3 and setting it as hot water supply temperature can be considered (low temperature pre-mixing). In the present embodiment, the mixing temperature in the first mixing valve 6 is set to a temperature that is higher than the hot water supply temperature by a predetermined temperature. In this connection configuration, the first mixing valve 6 is set to a temperature that is lower than the hot water supply temperature by a predetermined temperature. Mix.

  In the configuration of FIG. 9 as well, when the pump 25 drains the hot water in the hot water tank 1, the hot water storage tank can prevent freezing damage without generating residual water in the heat utilization circuit. In the vertical direction of the tank 1, the heat utilization return pipe 22 is disposed between the connection position of the hot water storage tank 1 and the connection position of the heat utilization hot water discharge pipe 21 to the hot water storage tank 1.

  That is, the heat utilization hot water pipe 21, the heat exchanger 20 connected to the heat utilization hot water pipe 21, and the heat utilization return so that no pipe exists at a position lower than the connection position of the hot water storage tank 1 of the heat utilization return pipe 22. By forming a heat utilization circuit with the pipe 22 and arranging a pump 25 in the heat utilization circuit, when draining hot water in the hot water tank 1, hot water does not remain in the heat utilization circuit due to its own weight, and freeze damage Can be prevented.

  In general, when temperature control is performed, it is a commonly used method to have a certain temperature range in consideration of the temperature distribution in the hot water tank 1 and the variation in the system of the temperature detection means. As described above, a difference occurs in the mixing temperature, and this affects the fluctuation of the hot water supply temperature when a portion with a large temperature gradient generated by the heat utilization return pipe 22 is discharged.

  FIG. 10 shows the difference in hot water supply temperature due to the difference in piping connection configuration. FIG. 10A corresponds to the time when the temperature distribution of FIG. 8A occurs. The temperature from the second tapping pipe is 45 ° C., and the temperature of the hot water discharged from the first tapping pipe is 65 ° C. The hot water supply temperature when the temperature of the hot water from the first hot water discharge pipe is rapidly lowered from the state of ° C and the control of the mixing valve cannot catch up is graphed. The set temperature at this time is 40 ° C.

  The graph with a circle is the hot water supply temperature of the high temperature premix in the pipe connection configuration in the present embodiment, and the graph with a cross is the hot water supply temperature in the case of the pipe connection configuration (low temperature premix) in which the low temperature is mixed first. . Since the temperature of the second hot water outlet pipe is equal to or higher than the hot water supply temperature in the high temperature pre-mix, even if the temperature of the hot water storage tank 1 drops rapidly, there is no effect because the hot water is discharged only from the second hot water outlet pipe. Mixing is likely to be affected by a decrease in the temperature of the first tapping pipe in order to obtain a final hot water supply temperature by mixing high temperatures.

FIG. 10 (b) corresponds to the time when the temperature distribution of FIG. 8 (b) occurs, and the temperature from the first tapping pipe is 65 ° C., and the temperature of the hot water discharged from the second tapping pipe. Is a graph showing the hot water supply temperature when the temperature of the hot water from the second hot water discharge pipe is suddenly lowered from the state where the temperature of the hot water is 30 ° C. and the control of the mixing valve cannot catch up. The set temperature at this time is 40 ° C.

  The graph with a circle is the hot water supply temperature of the high temperature premix in the pipe connection configuration in the present embodiment, and the graph with a cross is the hot water supply temperature in the case of the pipe connection configuration (low temperature premix) in which the low temperature is mixed first. .

  When the hot water temperature from the second hot water discharge pipe is a low temperature, for example, 30 ° C., the low temperature premixing is because the mixing temperature at the first mixing valve 6 is a predetermined temperature lower than the hot water supply temperature. Do not mix with the water supplied from the water supply pipe.

  For this reason, the flow rate of the hot water from the second hot water outlet pipe is larger than that in the case of the second hot water outlet pipe mixed with high temperature, and the rapid temperature of the hot water in the second hot water outlet pipe is easily affected by the decrease.

  As described above, the connection configuration shown in FIG. 1 makes it possible to supply hot water at a relatively stable hot water supply temperature against a large temperature gradient generated in the hot water storage tank.

  As described above, since the hot water supply apparatus according to the present invention reduces the decrease in efficiency due to the use of the heat utilization terminal when using the heat of the hot water in the hot water storage tank, it can be applied to the domestic hot water supply apparatus as described above. In addition, the system having a heat source and a hot water storage tank can be applied to large-scale applications such as for business use and can provide excellent energy saving.

1 Hot water tank 2 Heating means (heat pump device)
DESCRIPTION OF SYMBOLS 3 1st hot water pipe 4 2nd hot water pipe 5 Water supply pipe 6 1st mixing valve 7 2nd mixing valve 8 Hot water discharge pipe merge pipe 9 Mixed water pipe 10 Feed water branch pipe 11 Hot water outlet 12 Middle temperature detection means 13 Combined temperature detection Means 14 Hot water supply temperature detection means 16 Boiling pipe 20 Heat exchanger 21 Heat utilization hot water discharge pipe 22 Heat utilization return pipe 23 Heat utilization terminal 24 Heat utilization temperature detection means 25 Pump (circulation means)
30 Hot water supply temperature setting means 31 Heat utilization temperature setting means 32 Control means 33 Control device

Claims (2)

A hot water storage tank, a first hot water pipe connected to the upper part of the hot water tank, a water supply pipe connected to the lower part of the hot water tank, and the first hot water pipe connected in the vertical direction of the hot water tank A second tapping pipe connected between a position and a position where the water supply pipe is connected; a heat-utilizing hot water pipe connected to an upper portion of the hot water storage tank; and a heat exchange connected to the heat-utilizing hot water pipe Connected to the hot water storage tank at a position higher than the connection position of the hot water storage tank of the second outlet pipe in the vertical direction of the hot water storage tank. A circulation means for circulating hot water in a heat utilization circuit composed of a utilization return pipe, the heat utilization hot water pipe, the heat exchanger, and the heat utilization return pipe, and the circulation means is the hot water storage tank. In the vertical direction of the heat utilization return pipe at a position higher than the connection position of the hot water storage tank. Hot water storage type hot water supply apparatus characterized by being location. A water supply branch pipe branched from the water supply pipe, a first mixing valve in which the second hot water outlet pipe and the first hot water outlet pipe are connected to the inlet side, and an outlet side of the first mixing valve. A connected hot water pipe merging pipe, a second mixing valve in which the hot water merging pipe merging pipe and the water supply branch pipe are connected to the inlet side, and a mixed water pipe connected to the outlet side of the second mixing valve; The hot water storage type hot water supply apparatus according to claim 1, comprising: