JP6207411B2 - Hot water storage water heater - Google Patents

Description

  Embodiments described herein relate generally to a hot water storage type water heater.

  2. Description of the Related Art In recent years, hot water storage water heaters that store water in a hot water storage tank, heat the water using inexpensive nighttime power, and store the heated hot water in the hot water storage tank have become widespread.

  In such a hot water storage type water heater, during the boiling operation for heating the water in the hot water storage tank, the hot water (water or hot water) in the hot water storage tank expands in volume and the pressure in the hot water storage tank rises. A phenomenon occurs in which gas (mainly oxygen) dissolved in the inside becomes bubbles and accumulates in the upper part of the hot water storage tank.

  Therefore, in order to prevent an increase in pressure in the hot water storage tank, a pressure relief valve for draining hot water in the hot water storage tank (hereinafter referred to as “expanded water”) that has been volume-expanded is provided at the upper part of the hot water storage tank (for example, , See Patent Document 1 below). By providing such a pressure relief valve, the gas accumulated in the upper part of the hot water storage tank can be discharged together with the expanded water.

Japanese Patent No. 5308712

  However, the hot water in the hot water tank is hot at the top and cold at the bottom, so providing a pressure relief valve at the top of the hot water tank drains the hot water located at the top of the hot water tank, Energy loss increases.

  An object of an embodiment of the present invention is to provide a hot water storage type hot water heater capable of reducing a loss of thermal energy when the expansion water is drained to prevent an increase in pressure in the hot water storage tank during boiling operation. .

A hot water storage type water heater of an embodiment includes a hot water storage tank for storing hot water heated by a heating device, a lower pipe connected to a lower part of the hot water storage tank, and a first pressure relief valve provided in the middle of the lower pipe. And an upper pipe connected to the upper part of the hot water storage tank, a middle pipe connected to the middle part of the hot water storage tank, hot water taken out from the upper pipe connected to the upper pipe and the middle pipe, and the middle part An intermediate mixing valve that mixes the hot water taken out from the piping, a hot water mixing valve that mixes the hot water that has passed through the intermediate mixing valve and the supply water, and guides it to the hot water supply destination, and hot water that has passed through the intermediate mixing valve A mixing valve for a bathtub that mixes and leads water to the bathtub, a mixing valve for the bathtub that mixes hot water and supply water that has passed through the intermediate mixing valve and leads to the bathtub, and a second that is provided in the middle of the upper pipe Used for the pressure relief valve and the lower pipe A pressure reducing valve that depressurizes the water to be discharged, wherein the valve opening set pressure of the second pressure relief valve is higher than the valve opening set pressure of the first relief valve, and the valve opening set pressure of the first relief valve is It is characterized by being higher than the valve opening set pressure of the pressure reducing valve.

It is a system diagram of the hot water storage type water heater of the first embodiment. It is a system diagram of the hot water storage type water heater of the second embodiment.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIG. The hot water storage type water heater 1 of the first embodiment includes a hot water storage tank 2 and a heating device 3 that heats water by a heat pump refrigeration cycle using, for example, CO ₂ refrigerant. The hot water storage tank 2 is a sealed tank and is always filled with hot water when in use. Further, a plurality of temperature sensors (not shown) are provided in the vertical direction on the side surface of the hot water storage tank 2 to measure the temperature distribution in the hot water storage tank 2. The hot water stored in the hot water storage tank 2 becomes hot water at the upper part and becomes cold water at the lower part due to the density change according to the temperature. The hot water storage tank 2 and the heating device 3 are connected by a boiling pipe 4. The boiling pipe 4 has one end connected to the lower part of the hot water storage tank 2 and the other end connected to the upper part of the hot water storage tank 2, sucking low temperature hot water from the lower part of the hot water storage tank 2, and supplying hot water heated by the heating device 3. The hot water storage tank 2 is supplied to the upper part.

  In addition to the boiling piping 4, various piping is connected to the hot water storage tank 2, and a drainage piping 5 and a water supply piping 6 that is a lower piping are connected to the lower portion of the hot water storage tank 2. The drainage pipe 5 is a pipe for draining hot water in the hot water storage tank 2, and a drain plug 7 is provided at the tip thereof. The water supply pipe 6 is a pipe for supplying supply water such as tap water into the hot water storage tank 2, and a pressure reducing valve 8 and a first pressure relief valve 9 are provided in the middle thereof. The pressure reducing valve 8 is a valve for reducing the pressure of the supply water supplied to the hot water storage tank 2 to a set pressure or less. The first pressure relief valve 9 is arranged between the pressure reducing valve 8 and the lower part of the hot water storage tank 2, and when the pressure in the hot water storage tank 2 rises to a set pressure during the boiling operation for heating the hot water in the hot water storage tank 2. The valve is opened to discharge a part of the hot water in the hot water storage tank 2 to the outside of the hot water storage tank 2.

  An upper pipe 10 is connected to the upper part of the hot water storage tank 2 in addition to the boiling pipe 4 described above, and a middle pipe 11 is connected to the middle part of the hot water storage tank 2 in the vertical direction. The upper pipe 10 is a pipe for taking out hot water in the hot water storage tank 2 from the upper part of the hot water storage tank 2, and the middle pipe 11 is a pipe for taking out hot water in the hot water storage tank 2 from the middle part of the hot water storage tank 2.

  An intermediate mixing valve 12 is provided at the tip of the upper pipe 10 and the middle pipe 11. The intermediate mixing valve 12 is a valve for mixing hot water taken out from the upper part of the hot water storage tank 2 through the upper pipe 10 and hot water taken out from the middle part of the hot water storage tank 2 through the middle pipe 11. The opening degree can be adjusted so that the mixing ratio of the hot water taken out from the upper part of the hot water storage tank 2 and the hot water taken out from the middle part of the hot water storage tank 2 can be adjusted. The structure for adjusting the opening degree may be a structure in which the controller automatically adjusts based on various data on the operation of the hot water storage type hot water heater 1, for example, the elapsed time since the last use of hot water, the place where the hot water is used, etc. Alternatively, the structure may be adjusted manually as necessary.

  As a path through which hot water that has passed through the intermediate mixing valve 12 flows, a hot water supply path 14 that leads hot water to hot water taps 13 of various hot water destinations such as a washroom and a kitchen, and a bathtub pipe 16 that leads to a bathtub 15 are provided. In the middle of the hot water supply path 14, a hot water supply mixing valve 17 for mixing hot water flowing through the hot water supply path 14 and supply water such as tap water is provided. In addition, a flow sensor (not shown) is provided in the middle of the hot water supply mixing valve 17 and the hot water tap 13 in the hot water supply path 14 so as to detect the flow of hot water from the hot water tap 13. A bathtub mixing valve 18 that mixes hot water flowing in the bathtub pipe 16 and supply water such as tap water is provided in the middle of the bathtub pipe 16. Further, a bathtub hot water solenoid valve 20 is provided on the downstream side of the bathtub mixing valve 18 of the bathtub pipe 16. When performing a hot water supply operation for supplying hot water to the bathtub 15, the bathtub hot water solenoid valve 20 is opened, and hot water is supplied to the bathtub 15.

  In such a hot water storage type hot water heater 1, the heating device 3 is driven using inexpensive electric power at night, and a boiling operation for heating the water stored in the hot water storage tank 2 is performed at night. .

  When the boiling operation is started, the hot water in the hot water storage tank 2 expands, and the pressure in the hot water storage tank 2 gradually increases with this expansion. When the pressure in the hot water storage tank 2 rises to the set pressure, the first relief valve 9 is opened, and part of the hot water in the hot water storage tank 2 is drained out of the hot water storage tank 2 through the first relief valve 9. Then, the pressure in the hot water storage tank 2 is lowered and the first relief valve 9 is closed. Since the water supply pipe 6 provided with the first relief valve 9 is a pipe connected to the lower part of the hot water storage tank 2, a low temperature portion of the hot water in the hot water storage tank 2 passes through the first relief valve 9. It is drained out of the hot water storage tank 2, and the loss of thermal energy associated with draining part of the hot water in the hot water storage tank 2 as expansion water can be reduced.

  When the hot water in the hot water storage tank 2 is supplied to various hot water supply destinations and the bathtub 15, the hot water in the upper part of the hot water storage tank 2 taken out from the upper pipe 10 and the middle part of the hot water storage tank 2 taken out from the central pipe 11. Hot water is mixed by the intermediate mixing valve 12, and the hot water mixed by the intermediate mixing valve 12 is mixed with the supply water by the hot water mixing valve 17 or mixed with the supply water by the bathtub mixing valve 18 so as to have an appropriate temperature. After the temperature is adjusted, the hot water is supplied to various hot water supply destinations and the bathtub 15.

  During the boiling operation, the gas (mainly oxygen) contained in the hot water becomes bubbles and accumulates in the upper part of the hot water storage tank 2. Here, when the hot water in the upper part of the hot water storage tank 2 is taken out through the upper pipe 10, the gas accumulated in the upper part of the hot water storage tank 2 is discharged together with the hot water through the upper pipe 10. It is possible to prevent the gas from being accumulated in the upper part of the gas tank and to prevent a large amount of gas from accumulating in the hot water storage tank 2.

  Further, in order to prevent the gas accumulated in the upper part of the hot water storage tank 2 from being blown out from the hot water supply destination at once, the opening of the intermediate mixing valve 12 is set so that the ratio of hot water taken out through the upper pipe 10 is reduced. You can adjust. For example, when the opening degree of the intermediate mixing valve 12 is automatically adjusted by the control device, the hot water is used after a set time has elapsed since the previous hot water use, and gas is accumulated in the upper part of the hot water storage tank 2. The opening degree may be adjusted so that the ratio of hot water taken out through the upper pipe 10 is reduced at a timing at which it can be predicted. On the other hand, when hot water is used in the bathtub 15, there is no particular problem even if the gas in the hot water storage tank 2 blows into the bathtub 15 at a stretch, so that the ratio of hot water taken out through the upper pipe 10 is reduced. It is not necessary to adjust the opening degree.

  Also, for example, after the boiling operation at night is completed and a predetermined time has elapsed, when no hot water is used in the various hot water taps 13, the opening degree of the intermediate mixing valve 12 and the bathtub mixing valve 18 is adjusted, The upper pipe 10 and the bathtub pipe 16 are communicated, and the bathtub hot water supply solenoid valve 20 is opened. Thereby, the gas accumulated on the hot water storage tank 2 can be discharged to the bathtub 15.

  Moreover, when discharging | emitting gas to the bathtub 15, the opening degree of the mixing valve 17 for hot water supply is adjusted so that the hot water supply path 14 side may be closed or an opening degree may be made small. Thereby, even when the user opens the hot-water tap 13 while discharging the gas to the bathtub 15, the gas does not blow out from the hot-water tap 13.

  Further, when the hot water tap 13 is opened and the use of hot water is started, the opening of the intermediate mixing valve 12 is adjusted so that the middle pipe 11 side becomes larger, and then the opening of the hot water mixing valve 17 is adjusted. Hot water of a predetermined temperature is supplied to the hot water tap 13.

  Thereby, the hot gas of the hot water storage tank 2 upper part can be discharged | emitted to the bathtub 15, a hot gas does not blow off to the various hot-water taps 13, and a user can use hot water safely.

(Second Embodiment)
A second embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same component as the component demonstrated in 1st Embodiment, and the overlapping description is abbreviate | omitted.

  The basic configuration of the hot water storage type hot water heater 1A of the second embodiment is the same as that of the hot water storage type hot water heater 1 of the first embodiment. That is, the hot water storage type water heater 1A includes a hot water storage tank 2 and a heating device 3, and further includes a water supply pipe 6, a pressure reducing valve 8, a first relief valve 9, an upper pipe 10, an intermediate pipe 11, and an intermediate mixing valve 12. , A hot water supply mixing valve 17 and a bathtub mixing valve 18 are provided.

  A second pressure relief valve 19 is provided in the middle of the upper pipe 10 and between the hot water storage tank 2 and the intermediate mixing valve 12. The second relief valve 19 is opened when the pressure in the hot water storage tank 2 rises to a set pressure during the boiling operation for heating the hot water in the hot water storage tank 2, and a part of the hot water in the hot water storage tank 2 is stored in the hot water storage tank. 2 Functions to drain outside. Further, when the supply water is supplied into the hot water storage tank 2 or when the hot water in the hot water storage tank 2 is drained, the valve is opened so that air enters and exits the hot water storage tank 2.

  Here, the valve opening set pressure values of the pressure reducing valve 8, the first relief valve 9, and the second relief valve 19 are set so that the first relief valve 9 has a valve opening set pressure higher than that of the pressure reducing valve 8. Reference numeral 19 denotes a valve opening set pressure higher than that of the first relief valve 9.

  In such a configuration, when supplying water into the hot water storage tank 2, the air in the hot water storage tank 2 can be exhausted from the second relief valve 19 by opening the second relief valve 19. The supply water can be easily supplied in a short time. In addition, when the hot water in the hot water storage tank 2 is drained from the drain pipe 5, the second relief valve 19 is opened so that air can smoothly flow into the hot water storage tank 2. The drainage from the inside can be easily performed in a short time.

  In addition to the first relief valve 9, the hot water storage type hot water heater 1 </ b> A is provided with a second relief valve 19, and the pressure setting value of the second relief valve 19 is set higher than that of the first relief valve 9. For this reason, the second relief valve 19 also serves as a double protection function for preventing an abnormal pressure rise in the hot water storage tank 2, and even when the first relief valve 9 is malfunctioning, the hot water storage type hot water heater 1A can be improved.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Hot water storage type water heater, 1A ... Hot water storage type water heater, 2 ... Hot water storage tank, 3 ... Heating device, 6 ... Pipe for water supply (lower piping), 9 ... First relief valve, 10 ... Upper piping, 11 ... Middle piping , 12 ... Intermediate mixing valve, 15 ... Bathtub, 17 ... Hot water mixing valve, 18 ... Bathtub mixing valve, 19 ... Second pressure relief valve

Claims (1)

A hot water storage tank for storing hot water heated by a heating device;
A lower pipe connected to the lower part of the hot water storage tank;
A first pressure relief valve provided in the middle of the lower pipe;
An upper pipe connected to the upper part of the hot water storage tank;
A middle pipe connected to the middle of the hot water storage tank;
An intermediate mixing valve that is connected to the upper pipe and the middle pipe and mixes hot water taken out from the upper pipe and hot water taken out from the middle pipe;
A hot water mixing valve that mixes the hot water that has passed through the intermediate mixing valve and the feed water and guides it to the hot water supply destination;
A mixing valve for a bathtub that mixes the hot water that has passed through the intermediate mixing valve and the supply water and guides it to the bathtub;
A second pressure relief valve provided in the middle of the upper pipe;
A pressure reducing valve for reducing the pressure of water supplied to the lower pipe,
The valve opening set pressure of the second pressure relief valve is higher than the valve opening set pressure of the first relief valve, and the valve opening set pressure of the first relief valve is higher than the valve opening set pressure of the pressure reducing valve. Hot water storage water heater.

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