JP6111861B2 - Hot water storage system - Google Patents

Description

  The present invention relates to a hot water storage and hot water supply apparatus, and more particularly to an improved water drainage structure of a bypass pipe connecting a water supply pipe and a hot water supply pipe by bypassing a hot water storage tank and a branch pipe connecting the bypass pipe and the hot water supply pipe.

  2. Description of the Related Art Conventionally, hot water storage and hot water supply devices having functions such as hot water supply to hot water heating terminals such as hot water storage, hot water supply, and floor heating panels, hot water supply to a bath, and reheating are widely used. This hot water storage hot water supply device is a hot water storage tank for storing hot water heated by an external heat source device, a water supply pipe for supplying cold hot water to the hot water storage tank, and a desired hot water supply destination such as a hot water tap for hot water stored in the hot water storage tank. Hot water supply piping to supply water, heating water heating circuit for supplying heating water to hot water heating equipment such as floor heating panels, bath hot water supply and reheating circuit for hot water supply and reheating, hot water heating circuit and bath hot water supply reheating circuit A heat utilization circulation circuit is provided.

  Further, the hot water storage and hot water supply apparatus includes a bypass pipe that connects the water supply pipe and the hot water supply pipe by bypassing the hot water storage tank, and a mixing valve that is installed at a junction of the bypass pipe and the hot water supply pipe. Hot water and water are mixed and hot water is supplied. It also has a branch pipe that branches off from the bypass pipe and is connected to the hot water supply pipe without going through the mixing valve, and an on-off valve for avoiding high-temperature hot water that is installed in this branch pipe. Prevents hot hot water from being discharged from a hot water tap or the like.

  As a structure for avoiding high temperature hot water as described above, for example, in Patent Document 1, a branch pipe branched from a bypass pipe is connected to a hot water pipe on the upstream side of the mixing valve, and the branch pipe is connected from the bypass pipe to the hot water pipe. There is also disclosed a structure that prevents hot water from being discharged by installing a check valve that allows the flow of water and preliminarily mixing with water before reaching the mixing valve to lower the temperature of the hot water.

  By the way, in the conventional hot water storage hot-water supply apparatus and the hot-water storage water heater of patent document 1, the check valve for preventing the backflow of the water to a water supply source is generally installed in bypass piping or water supply piping. For this reason, water stays in the pipe downstream from the check valve when draining during operation switching or maintenance. In order to solve this problem, a dedicated drainage pipe is connected to the pipe downstream from the check valve, and a drain plug at the downstream end of the drainage pipe is used when switching to a non-operational state or during maintenance. It is necessary to operate and drain the water.

JP 2003-222407 A

  However, in the conventional hot water storage and hot water supply apparatus and the hot water heater of Patent Document 1, if drain pipes and drain plugs for draining are installed in the bypass pipe, the number of parts increases and the assembly takes time. It becomes. In addition, when the number of drain plugs increases, there is a problem that it takes time to drain water and takes time for maintenance work.

  An object of the present invention is to provide a hot water storage and hot water supply apparatus having a structure capable of reducing manufacturing costs, a structure having a structure capable of simplifying a water draining operation, and the like.

  The hot water storage and hot water supply apparatus according to claim 1 is branched from the hot water storage tank for storing hot water, a water supply pipe connected to the lower part of the hot water storage tank, a hot water supply pipe connected to the upper part of the hot water storage tank, and the water supply pipe. A bypass pipe connected to the hot water piping, a mixing means installed at the junction of the bypass pipe and the hot water piping, and a branch branched from the bypass pipe and connected to the hot water piping on the downstream side of the mixing means In a hot water storage and hot water supply apparatus comprising a pipe, an on-off valve for avoiding high-temperature hot water installed in the branch pipe, and a check valve installed in the bypass pipe upstream of a branch portion where the branch pipe branches The branch pipe and the on-off valve are installed so as to be positioned below the check valve.

  A hot water storage and hot water supply apparatus according to a second aspect is characterized in that, in the invention according to the first aspect, the mixing means is installed so as to be positioned above the check valve.

  According to the invention of claim 1, the hot water storage hot water supply apparatus includes a hot water storage tank, a water supply pipe, a hot water discharge pipe, a bypass pipe, a mixing means installed at a junction of the bypass pipe and the hot water discharge pipe, and a bypass. A branch pipe branched from the pipe and connected to the hot water supply pipe on the downstream side of the mixing means, an on-off valve for avoiding high-temperature hot water provided in the branch pipe, and a bypass pipe upstream of the branch portion where the branch pipe branches. Since the branch pipe and the on-off valve are installed below the check valve, they are open when draining, except during the hot water operation, and when high temperature hot water is detected. Using the on / off valve for avoiding high temperature hot water, hot water staying in the bypass pipe and branch pipe downstream from the check valve is led to the hot water pipe through the on / off valve for avoiding high temperature hot water, and the hot water connected to this hot water pipe Through plugs and drain plugs It can be drained to the outside Te.

  Therefore, it is necessary to omit the draining work downstream from the check valve of the conventional bypass pipe, simplify the draining work, shorten the maintenance work time, and connect the drain pipe to the bypass pipe. Therefore, the manufacturing cost can be reduced.

  According to the invention of claim 2, since the mixing means is installed so as to be positioned above the check valve, natural convection is generated in the vicinity of the mixing means, and hot hot water is fed from the tap pipe through the mixing means. By preventing the flow toward the bypass pipe, it is possible to prevent deterioration of the hot water discharge characteristics.

It is a schematic block diagram of the hot water storage hot-water supply apparatus which concerns on an Example. It is a front view of water supply piping, bypass piping, and branch piping. It is a side view of water supply piping, bypass piping, and branch piping.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

Next, the whole structure of the hot water storage hot water supply apparatus 1 of this invention is demonstrated.
As shown in FIG. 1, a hot water storage and hot water supply apparatus 1 has functions such as hot water storage, hot water supply, hot water supply to a hot water heating terminal such as a floor heating panel, hot water supply to a bath, and reheating. , Auxiliary heat source unit 3, first and second heat exchangers 4, 5, water supply piping 6, hot water piping 7, heating circulation circuit 8, bath hot water supply circuit 9, hot water heating circuit 11, heat utilization circulation circuit 12, control A unit 13, a bypass pipe 17, a branch pipe 18, and the like are provided, and most of them are integrally stored in the outer case 14.

  The hot water storage hot water supply device 1 is a fuel cell power generation device capable of heating hot water in the hot water storage tank 2 as an external heat source device, and heating circulation for circulating hot water between the fuel cell power generation device and the hot water storage hot water supply device 1. A fuel cell cogeneration system is configured by combining with the circuit 8 or the like, but detailed description of the configuration other than the hot water storage hot water supply device 1 is omitted.

Next, the hot water tank 2, the auxiliary heat source unit 3, and the first and second heat exchangers 4 and 5 will be described.
As shown in FIG. 1, the hot water tank 2 is composed of a sealed tank capable of storing high-temperature hot water (for example, 80 to 90 ° C.) heated by an external heat source machine, and prevents heat dissipation of the stored hot water. The tank is covered with insulation.

  The auxiliary heat source unit 3 is provided in the heat utilization circulation circuit 12 and is configured by a known gas water heater that burns fuel gas and heats hot water. The auxiliary heat source unit 3 includes a blower fan 3a for supplying combustion air, a burner unit 3b for burning fuel gas, a sensible heat recovery heat exchanger 3c for recovering mainly sensible heat of the combustion gas, and sensible heat A latent heat recovery heat exchanger 3d for recovering mainly latent heat of the recovered combustion exhaust gas is provided.

  The auxiliary heat source unit 3 sends a command from the main control unit 13 only when the temperature of the hot water in the hot water tank 2 is lower than the set temperature or when the temperature of the hot water circulating in the heat utilization circulation circuit 12 is insufficient. The hot water flowing through the heat utilization circulation circuit 12 is reheated and reheated.

  The first heat exchanger 4 heats the bath water flowing through the bath hot water supply circuit 9, and forms a part of the heat exchange passage 4 a and the bath hot water supply circuit 9 that are part of the heat utilization circulation circuit 12. It has an internal passage portion 4b. In the 1st heat exchanger 4, heat exchange is carried out between the hot hot water which flows through the heat utilization circuit 12, and the bathtub water which flows through the bath hot water supply circuit 9, and the bathtub water is heated.

  The 2nd heat exchanger 5 heats the heating water which flows through the hot water heating circuit 11, and heat exchange passage part 5a which becomes a part of heat utilization circulation circuit 12, and heat exchange which becomes a part of the hot water heating circuit 11 It has a passage 5b. In the second heat exchanger 5, heat is exchanged between the hot water flowing through the heat utilization circuit 12 and the heating water flowing through the hot water heating circuit 11, and the heating water is heated.

Next, the heating circulation circuit 8 will be described.
As shown in FIG. 1, the heating circulation circuit 8 is a closed circuit for circulating hot water between the hot water tank 2 and the external heat source machine, and has an outward circulation passage portion 8a and a return circulation passage portion 8b. The upstream end is connected to the lower part of the hot water tank 2, and the downstream end is connected to the upper part of the hot water tank 2 via an external heat source machine in the middle part. A bypass passage portion 8c connected to the return-side circulation passage portion 8b is branched from the forward-side circulation passage portion 8a, and a hot water storage switching valve 8d is installed at this branch portion.

  In normal heating circulation operation, as shown in FIG. 1, the hot water storage switching valve 8d is switched to the side that shuts off the bypass passage portion 8c, and hot water is circulated from the hot water storage tank 2 via a circulation pump (not shown). Passing through the passage portion 8a and being heated by being sent to the external heat source machine, the heated hot water is returned to the hot water tank 2 through the return side circulation passage portion 8b (see the arrow in FIG. 1).

Next, the water supply pipe 6 and the hot water supply pipe 7 will be described.
The water supply pipe 6 supplies low temperature clean water from a water supply source to the hot water storage tank 2, and has an upstream water supply passage portion 6a, an intermediate water supply passage portion 6b, and a downstream water supply passage portion 6c. The downstream end is connected to the lower part of the hot water tank 2. A pressure reducing valve 6d (pressure reducing device) is installed in the upstream water supply passage 6a, and a check valve 6e is installed in the intermediate water supply passage 6b.

  A bypass passage portion 16 connected to the heat utilization circuit 12 is branched from between the intermediate water supply passage portion 6b and the downstream water supply passage portion 6c, and a heat storage switching valve 6g is installed at this branch portion. By this bypass passage 16, low temperature clean water can be supplied to the heat utilization circuit 12, and conversely, hot water can be returned from the heat utilization circuit 12 to the hot water tank 2.

  The hot water supply pipe 7 supplies hot water stored in the hot water tank 2 to a desired hot water supply destination such as a hot water tap, an upper effluent hot water passage portion 7a through which hot hot water flows, and a lower effluent hot water passage through which mixed hot water flows. The upper end of the hot water storage tank 2 is connected, and the downstream end is connected to the hot water tap. A mixing valve 21 is installed between the upper effluent hot water passage portion 7a and the lower effluent hot water passage portion 7b.

  An outlet hot water proportional valve 19a is installed in the middle of the lower outlet hot water passage section 7b of the outlet hot water piping 7, and a bath outlet hot water passage 19 connected from the downstream side of the outgoing hot water proportional valve 19a to the bath hot water supply circuit 9 is branched. Has been. A pouring solenoid valve 19b, a check valve 19c, and the like are integrally installed in the bath outlet passage 19 in order.

Next, the bath hot water supply circuit 9 and the hot water heating circuit 11 will be described.
As shown in FIG. 1, the bath hot water supply circuit 9 is a circuit for scooping hot water in the bath, and has a bath return passage portion 9a and a bath return passage portion 9b. An internal passage portion 4b of the first heat exchanger 4 is connected between the bath return passage portion 9a and the bath return passage portion 9b, and a bath circulation pump 9c is installed in the bath return passage portion 9a.

  The hot water heating circuit 11 is a circuit that circulates heating water supplied to hot water heating terminals such as a floor heating panel and a bathroom dryer, and has a heating return passage portion 11a, a heating high-temperature passage portion 11b, and a heating low-temperature passage portion 11c. have. An expansion tank 11d and a heating circulation pump 11e are installed in the heating return passage portion 11a. A heat exchange passage portion 5b of the second heat exchanger 5 is interposed in the heating high temperature going passage portion 11b.

Next, the heat utilization circulation circuit 12 will be described.
The heat utilization circulation circuit 12 is a closed circuit that circulates hot water and performs heat exchange with the hot water heating circuit 11 and the bath hot water supply circuit 9, and includes a hot and cold water passage section 12 a, an auxiliary heat source machine forward passage section 12 b, It has a heat exchanger forward passage portion 12c and a hot water return passage portion 12d.

  The upstream end of the hot water going-out passage portion 12a is connected to the upper part of the hot water storage tank 2, and the junction between the downstream end of the hot-water going-up passage portion 12a, the upstream end of the auxiliary heat source unit going-out passage portion 12b, and the downstream end of the hot water return passage portion 12d. Is provided with a three-way valve 12e. A check valve 12f is installed in the hot water going-out passage section 12a, and a pressurizing pump 12g for sending hot water to the latent heat recovery heat exchanger 3d is installed in the auxiliary heat source machine going-out passage section 12b.

  A latent heat recovery heat exchanger 3d and a sensible heat recovery heat exchanger 3c of the auxiliary heat source unit 3 are connected between the auxiliary heat source unit forward passage 12b and the heat exchanger forward passage 12c. Between the pair of branch passages in the downstream portion of the heat exchanger forward passage portion 12c and the pair of branch passages in the upstream portion of the hot water return passage portion 12d, the first and second heat exchangers 4 and 5 The heat exchange passages 4a and 5a are connected to each other. A first heat exchange outlet solenoid valve 12h and a second heat exchange outlet solenoid valve 12i are respectively installed in the pair of branch passages of the hot water return passage portion 12d.

  A hot water passage portion 12j connected to the hot water piping 7 is branched from the heat exchanger forward passage portion 12c, and a tank water proportional valve 12k is installed in the hot water passage portion 12j. The hot water heated by the auxiliary heat source unit 3 can be supplied to the hot water piping 7 by the hot water passage portion 12j.

Next, the bypass pipe 17 and the branch pipe 18 will be described.
As shown in FIGS. 1 to 3, the bypass pipe 17 is branched from between the upstream water supply passage section 6 a and the intermediate water supply passage section 6 b (the branch section 20) and bypasses the hot water tank 2 and is connected to the hot water supply pipe 7. Has been. The bypass pipe 17 is provided with a check valve 22 for preventing a back flow of water to the water supply source. The bypass pipe 17 has an upstream bypass passage portion 17a upstream of the check valve 22 and a downstream bypass passage portion 17b downstream of the check valve 22, and is configured in a substantially U shape in front view.

  A mixing valve 21 (corresponding to a mixing means) is installed at the junction between the bypass pipe 17 and the hot water supply pipe 7. That is, the mixing valve 21 is connected to the downstream end of the upper and lower hot water passage portions 7a and 7b of the outlet piping 7 and the downstream end of the downstream bypass passage portion 17b of the bypass piping 17 and the downstream end of the downstream piping passage 17b. It is connected.

  The branch pipe 18 is branched from the branch portion 25 of the downstream bypass passage portion 17b and connected to the lower effluent passage portion 7b on the downstream side of the mixing valve 21. The branch portion 25 is provided in an upstream portion (lower portion) of the crank-shaped downstream bypass passage portion 17b. The branch pipe 18 is provided with an on-off valve 23 for avoiding high temperature hot water. The branch pipe 18 has an upstream branch passage portion 18 a upstream of the on-off valve 23 and a downstream branch passage portion 18 b downstream of the on-off valve 23. The upstream branch passage portion 18a is configured in a substantially L shape when viewed from the front. By the branch pipe 18, low temperature clean water can be supplied from the clean water source to the bottom outflow hot water passage portion 7b.

  The on / off valve 23 for avoiding high temperature hot water is composed of an electromagnetic valve that is driven to open and close when a command is transmitted from the main control unit 13, and is set to a closed state during normal hot water operation, By setting the open state at the time of detection, hot water is prevented from being discharged from a hot water tap or the like by mixing water with hot water at the time of a power failure or when the mixing valve 21 fails.

Next, a specific installation structure in the vicinity of the bypass pipe 17 and the branch pipe 18 according to the present invention will be described.
As shown in FIGS. 2 and 3, the upstream bypass passage portion 17 a of the bypass pipe 17 branched from the branch portion 20 of the water supply pipe 6 extends horizontally in the right direction, bends at a right angle upward, and extends in the vertical direction. The shaft 22A is bent at a right angle to the left and is connected to the introduction port of the check valve 22 facing in the left-right direction.

  The downstream bypass passage portion 17b extends in a crank shape from the discharge port of the check valve 22, and is connected to a low temperature clean water inlet of the mixing valve 21 in which the axis 21A of the valve shaft extends in the front-rear direction. The upstream branch passage portion 18a of the branch pipe 18 branched from the branch portion 25 of the downstream bypass passage portion 17b extends vertically downward, bends to the left at a right angle, extends horizontally to the left, The shaft center 23A is connected to the inlet of the on-off valve 23 extending in the front-rear direction.

  Here, in the height positional relationship of the branch pipe 18, the mixing valve 21, the check valve 22, and the on-off valve 23, the mixing valve 21 is located above the check valve 22 as shown in FIGS. 2 and 3. The branch pipe 18 and the on-off valve 23 are installed so as to be positioned below the check valve 22.

  That is, the horizontal plane 31 including the axial center 21A of the mixing valve 21 is set to be positioned above the horizontal plane 32 including the axial center 22A of the check valve 22 by a height α, and the axial center 22A of the check valve 22 is set. Is set so as to be located above the horizontal plane 33 including the axial center 23A of the on-off valve 23 by a height β. The heights α and β are set to be higher than the height α, but it is not particularly limited to this height positional relationship.

  As described above, the arrangement relationship of the various pipes 17 and 18 and the various valves 21 to 23 is such that the inlet for the low-temperature water supply of the mixing valve 21 and the downstream bypass passage portion 17b from the higher side toward the lower side. At the downstream end, the upstream end of the downstream bypass passage portion 17b, the discharge port of the check valve 22, the upstream end of the upstream branch passage portion 18a, the downstream end of the upstream branch passage portion 18a, and the inlet of the on-off valve 23. When the on-off valve 23 is in the open state, the water staying in the downstream bypass passage portion 17b and the upstream branch passage portion 18a flows from the upper side to the lower side through the on-off valve 23 to the downstream branch passage portion 18b. A downward flow is formed.

Next, the operation and effect of the hot water storage and hot water supply apparatus 1 of the present invention will be described.
The hot water supply operation of the hot water storage hot water supply device 1 is started together with the opening of the hot water tap. Due to the water pressure of the water source, the water enters the lower part of the hot water tank 5 from the water supply pipe 6, whereby hot hot water is pushed out from the upper part of the hot water tank 5 into the upper effluent hot water passage 7 a and introduced into the mixing valve 21. Then, the clean water is introduced into the mixing valve 21 via the bypass pipe 17. The flow rate ratio of hot hot water and water mixed through the mixing valve 21 is controlled so that the hot water temperature becomes the command temperature, and the mixed hot water is discharged from the hot water tap through the lower outlet hot water passage portion 7b.

  The hot water storage and hot water supply device 1 requires regular maintenance. At the time of this maintenance, a water draining operation for draining hot water stored in the hot water storage tank 2 and water remaining in various pipes to the outside is required. There is a need to do. In draining the downstream bypass passage portion 17b of the bypass pipe 17 and the branch pipe 18 on the downstream side of the check valve 22, as described above, when the on-off valve 23 is in the open state, the downward flow is directed downward from above. Therefore, the water staying downstream from the check valve 22 is automatically drained to the outside through the lower effluent hot water passage portion 7b.

  As described above, the hot water storage and hot water supply apparatus 1 includes the hot water storage tank 2, the water supply pipe 6, the hot water supply pipe 7, the bypass pipe 17, and the mixing valve installed at the junction of the bypass pipe 17 and the hot water supply pipe 7. 21, a branch pipe 18 branched from the bypass pipe 17 and connected to the tap water pipe 7 on the downstream side of the mixing valve 21, an on-off valve 23 for avoiding high temperature hot water provided in the branch pipe 18, and the branch pipe 18 are branched. Since the check valve 22 is provided in the bypass pipe 17 on the upstream side of the branch portion 25 and the branch pipe 18 and the opening / closing valve 23 are located below the check valve 22, At the time of draining, the water staying in the bypass pipe 17 and the branch pipe 18 on the downstream side of the check valve 22 is removed using the on / off valve 23 for avoiding the high temperature hot water that is open when the hot water is not being discharged and when the high temperature hot water is detected. Avoid hot hot water The leads to tapping pipe 7 through the opening and closing valve 23 can be drained to the outside through the connected hot-water tap and drain plug in the hot water pipe 7.

  Accordingly, it is possible to omit the water draining operation downstream of the check valve 22 of the conventional bypass pipe 17, simplify the water draining operation and shorten the maintenance work time, and connect the drain pipe to the bypass pipe 17. Since there is no need for connection, the manufacturing cost can be reduced.

  Moreover, since the mixing valve 21 is installed so as to be positioned above the check valve 22, natural convection occurs in the vicinity of the mixing valve 21, and high-temperature hot water is bypassed from the tap pipe 7 through the mixing valve 21. By preventing the flow toward the pipe 17, it is possible to prevent deterioration of the hot water discharge characteristics.

Next, a mode in which the above embodiment is partially changed will be described.
[1] In the above embodiment, the fuel cell power generation device has been described as the external heat source device. However, the present invention is not limited to this, and a heat pump type heating device, a gas engine, or the like may be adopted. Various well-known things are employable.

[2] In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. It is.

DESCRIPTION OF SYMBOLS 1 Hot water storage hot water supply equipment 2 Hot water storage tank 6 Water supply piping 7 Hot water supply piping 17 Bypass piping 18 Branch piping 21 Mixing valve 22 Check valve 23 On-off valve

Claims (2)

A hot water storage tank for storing hot water, a water supply pipe connected to the lower part of the hot water storage tank, a hot water supply pipe connected to the upper part of the hot water storage tank, and a bypass pipe branched from the water supply pipe and connected to the hot water supply pipe A mixing means installed at a junction of the bypass pipe and the outlet pipe, a branch pipe branched from the bypass pipe and connected to the outlet pipe downstream of the mixing means, and installed in the branch pipe. In a hot water storage and hot water supply apparatus comprising an on-off valve for avoiding high temperature hot water and a check valve installed in the bypass pipe on the upstream side of the branch part where the branch pipe branches,
The hot water storage and hot water supply apparatus is characterized in that the branch pipe and the on-off valve are installed to be positioned below the check valve. The hot water storage and hot water supply apparatus according to claim 1, wherein the mixing unit is installed so as to be positioned above the check valve.