JPH0632958U - Water heater - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent condensation on the heat exchanger surface and prolong the service life of the water heater. [Structure] The passage from the water supply pipe 3 to the heat exchanger 2 is connected to the hot water passage 30 side of the mixing unit 28, and the branched water supply pipe 27 branched from the water supply pipe 3 is connected to the water passage 29 side of the unit 28. Further, the hot water passing through the hot water passage 30 and the water passing through the water passage 29 are combined and mixed in the mixing chamber 42 in the unit 28 to obtain hot water having a predetermined temperature, and the hot water is discharged through the outlet passage 47. The hot water passage 30
Is provided with a dew condensation prevention valve 33 that opens only when the amount of water flowing exceeds the minimum operating flow rate of the device. Therefore, the dew condensation prevention valve 33 remains closed when a small amount of water cannot be heated by the heat exchanger 2, so that cold water does not pass through the heat exchanger 2 and no condensation occurs on the surface of the heat exchanger 2, so that heat exchange is performed. Corrosion of the vessel 2 can be prevented.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hot water supply device including hot water and water mixing means.

[0002]

[Prior art]

 FIG. 4 is a schematic diagram showing the structure of a conventional hot water supply apparatus and its usage. In the figure, a water supply pipe 3 is connected to the inlet side of the heat exchanger 2, and the inlet side of the water supply pipe 3 is connected to a water supply source side such as tap water via a flow sensor 9. A hot water supply pipe 11 is connected to the outlet side of the heat exchanger 2, and a tip end side of the hot water supply pipe 11 is piped to a desired hot water supply place, that is, a sink 13 in this figure, and a hot water supply pipe is provided near a sink. A stopper 12 is attached.

A burner 7 is arranged below the heat exchanger 2, a gas nozzle 6 is arranged opposite to a gas inlet of the burner 7, and a gas supply amount is opened to a gas pipe 14 leading to the gas nozzle 6. A proportional valve 8 which is controlled by the valve amount and a solenoid valve 10 which opens and closes the pipeline are provided.

A bypass passage 4 branches from the water supply pipe 3 and is arranged in parallel with the heat exchanger 2. The outlet end of the bypass passage 4 is connected to the hot water supply pipe 11 by a mixing portion 19.

A water heater 1 of this type is provided with a control device (not shown). In this control device, the flow sensor 9 detects the amount of water supplied, and when the amount of water supplied exceeds a certain amount (the minimum operating flow rate of the equipment (heat exchanger)), burner combustion is performed, and the heat exchanger 2 It is configured to control the heating of water passing through.

[0006] In this type of hot water supply equipment, when the hot water supply equipment 1 is used, when the hot water tap 12 is opened, water is supplied to the water supply pipe 3, and burner combustion occurs when the amount of water supply is at least the minimum operating flow rate of the equipment. The water passing through the heat exchanger 2 is heated to be hot water, which passes through the hot water supply pipe 11 and merges with the unheated water that has passed through the bypass passage 4 when reaching the mixing section 19 to be used temperature. Hot water is produced and this hot water is discharged into the sink 13 for use.

On the other hand, since the hot water tap 12 opens less, and as a result, the burner combustion does not occur unless the water supply amount is less than the minimum operating flow rate, the water passing through the heat exchanger 2 passes through the bypass passage 4 without being heated. It merges with the water and a small amount of water flows out into the sink 13.

[0008]

[Problems to be solved by the device]

 However, when the hot water supply device 1 having the above-mentioned configuration is used for commercial purposes in a restaurant or the like, water is stored in the sink 13 for washing dishes, and a small amount of clean water is constantly poured into the sink 13 to overflow the water. It is often the case that you leave it. In addition, the tableware used is often used intermittently with hot water. When a small amount of water is constantly discharged, the flow rate is less than the minimum operating flow rate of the heat exchanger 2, so the water passes through the heat exchanger 2 without being heated. On the other hand, when hot water is used, the amount of water supplied in the water supply pipe 3 is equal to or higher than the minimum operating flow rate of the heat exchanger 2, so that the heat exchanger 2 is heated by burner combustion.

Therefore, in the usage form for business purposes in which hot water is intermittently used and a small amount of water is poured into the sink 13 between the hot water, the heat exchanger 2 is heated immediately after it is heated by the use of the hot water, and then cold. Since water often passes and is rapidly cooled, dew condensation occurs on the surface of the heat exchanger 2 each time, and the heat exchanger 2 is corroded. Especially for business use, hot water and water are intermittently used frequently, so the service life is very short compared to household water heaters, for example, 1/10. there were.

The present invention has been made to solve the above-mentioned conventional problems, and its purpose is to pour a small amount of water between intermittently using hot water, even if the usage pattern is frequently repeated. The purpose of the present invention is to provide a water heater with a long service life by preventing the heat exchanger from corroding without causing dew condensation on the surface of the heat exchanger.

[0011]

[Means for Solving the Problems]

 The present invention is configured as follows to achieve the above object. That is, the present invention is a hot water supply device for heating water supplied from a water supply pipe through a heat exchanger and supplying hot water from the heat exchanger through the hot water supply pipe, in which a branch water supply pipe is branched from the water supply pipe. A mixing unit is connected to the outlet of the branch water supply pipe and the outlet of the hot water supply pipe, and in the mixing unit, a water passage leading to the branch water supply pipe, a hot water passage leading to the hot water supply pipe, and water from the water passage are connected. A mixing chamber where the hot water from the hot water passage joins and an outlet passage that goes out of the mixing chamber are provided, and the hot water passage supplies water at a minimum working flow rate or higher to the heat exchanger side. It is characterized by a dew condensation prevention valve of the heat exchanger that opens the hot water passage when the amount of water reaches a certain amount, and the dew condensation prevention valve is a differential pressure regulator between the upstream side and the downstream side of the valve. Is above the minimum operating flow rate of the device A differential pressure operated valve that opens when a pressure difference corresponding to the flow rate is reached.A flow sensor is installed in the outlet passage of the mixing unit and a dew condensation prevention valve installed in the hot water passage It is composed of a solenoid valve that opens the valve when the flow sensor detects that the amount of water that exceeds the operating flow rate has been supplied to the heat exchanger, and that the mixing chamber of the mixing unit has the mixing valve. A thermo control valve is provided to control the hot water temperature to a set temperature by sensing the hot water temperature in the room and varying the hot water passage opening amount and the water passage opening amount to adjust the mixing ratio of hot water and water. That is also a characteristic configuration of the present invention.

[0012]

[Action]

 In the present invention having the above-mentioned structure, when hot water is used, the water is supplied from the water supply pipe in an amount equal to or higher than the minimum working flow of the equipment, the heat exchanger is heated to heat the water, and the water is provided in the hot water passage of the mixing unit. The anti-condensation valve that is open opens, and the hot water passes through the anti-condensation valve and is mixed with the water that has passed through the water passage in the mixing chamber before being used through the outlet passage. On the other hand, when using a small amount of water, the heat exchanger does not heat up because the water supply pipe supplies less than the minimum operating flow rate of the equipment, and the dew condensation prevention valve closes, so the water supplied from the water supply pipe It is used without passing through the passage on the heat exchanger side, passing through the branch water supply pipe and passing through the mixing unit.

[0013]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same parts as those in the conventional example are designated by the same reference numerals, and the duplicate description thereof will be omitted. 1 and 2 show a first embodiment of a hot water supply device according to the present invention. FIG. 1 is a schematic diagram showing the structure of the first embodiment and its usage. The difference from the conventional one is that instead of the conventional bypass passage 4, a branch water supply pipe 27 that branches from the water supply pipe 3 is provided, and a mixing unit 28 that mixes water that has passed through the branch water supply pipe 27 and hot water that has passed through the hot water supply pipe 11 is provided. It is provided. The branch water supply pipe 27 and the mixing unit 28 are provided outside the hot water supply case 26. Other structures are similar to those of the conventional example.

FIG. 2 shows a detailed sectional view of the characteristic mixing unit 28 of this embodiment. In the figure, the inside of the unit case 43 is divided into upper and lower sides by the partition wall 5, the lower side is the mixing chamber 42, the upper side is further partitioned by the partition wall 15 into the left and right, and the left side is the heat exchanger 2 Side is a hot water passage 30 connected to the outlet side of the hot water supply pipe 11, and the right side is a water passage 29 connected to the outlet side of the branch water supply pipe 27. A hot water outlet 37a and a water outlet 36a are opened in the partition wall 5 as passages from the hot water passage 30 and the water passage 29 to the mixing chamber 42, respectively. An exit passage 47 is provided on the lower left side of the mixing chamber 42.

A valve port 18 is formed on the inlet side of the hot water passage 30, and a differential pressure actuating valve 33 as a dew condensation preventing valve is provided in the hot water passage 30 in the vicinity of the valve port 18. The differential pressure actuated valve 33 includes a valve body 46 and a spring 32. The valve body 46 is arranged so as to face the outlet side of the valve opening 18, and a spring 32 is interposed between the valve body 46 and the partition wall 5, and the valve body 46 constantly opens the valve opening 18 by the elastic restoring force of the spring 32. Acts to close. The strength of the spring 32 is such that the valve body 46 is operated when the differential pressure between the upstream side and the downstream side of the differential pressure actuated valve 33 becomes a pressure corresponding to the minimum working flow rate of the device (heat exchanger) or more. Designed to open.

A thermo control valve 48 is housed in the mixing chamber 42, and a spring 45 is interposed between the thermo control valve 48 and the left wall of the unit case 43 in a compressed state. The thermostatic control valve 48 is pressed against the right wall side of the unit case 43 by the elastic restoring force of. The thermo control valve 48 has a cylindrical cylinder 38, a partition plate 17, a temperature sensing part 39 and a spindle 40, and the temperature sensing part 39 and the spindle 40 are integrally configured with the cylinder 38 via the partition plate 17. Has become. The cylinder 38 is provided with a hot water inlet 37b and a water inlet 36b, and the partition plate 17 is provided with a hole 16. The tip of the spindle 40 is fitted and locked in the hot water temperature adjusting screw 41 embedded in the wall of the unit case 43.

When the hot water temperature adjusting screw 41 is moved back and forth, the positions of the hot water inlet 37b and the hot water inlet 36b provided in the thermo control valve 48 change with respect to the hot water outlet 37a and the hot water outlet 36a provided in the partition wall 5. As a result, the amount of hot water and the amount of water entering the mixing chamber 42 change, and hot water having a desired temperature corresponding to the ratio of the amount of hot water and the amount of water can be obtained.

This embodiment is configured as described above, and the hot water supply operation will be described next. When the hot-water tap 12 is opened when hot water is used, water exceeding the minimum operating flow rate flows from the water supply pipe 3 into the heat exchanger 2, so the heat exchanger 2 is heated by burner combustion and the water is heated, and the hot water supply pipe 11 to the valve opening 18 on the inlet side of the hot water passage 30 of the mixing unit 28. On the other hand, since the differential pressure between the upstream side and the downstream side of the differential pressure actuating valve 33 provided at this valve port 18 becomes a pressure corresponding to the minimum operating flow rate or more, the differential pressure actuating valve 33 is opened and the hot water is operated at the differential pressure. After passing through the valve 33, the hot water passage 30, the hot water inlets / outlets 37a and 37b, and then the mixing chamber 42. On the other hand, the water that has passed through the branch water supply pipe 27 passes through the water passage 29, enters the mixing chamber 42 through the water inlets / outlets 36a and 36b, mixes with the hot water that has entered the mixing chamber 42, and the thermo control valve 48. As a result, a predetermined temperature is reached and hot water is poured into the sink 13 to use the hot water.

At this time, if the mixing hot water temperature becomes higher than the set temperature set by the hot water temperature adjusting screw 41, the temperature sensing portion 39 expands with the fitting locking portion at the tip of the spindle 40 as a fulcrum, and the left side a The hot water inlet 37b and the hot water inlet 36b provided in the cylinder 38 integrally formed with the temperature sensing portion 39 are also displaced in the leftward a direction, so that the hot water inlet 37b and the hot water outlet 37a have matching openings. Since the area decreases and the area of the opening where the water inlet 36b and the water outlet 36a coincide increases, the amount of hot water decreases and the amount of water increases, so the hot water temperature drops to the set temperature. Further, when the mixing hot water temperature becomes lower than the set temperature, the temperature sensing part 39 contracts and the cylinder 38 shifts to the right side opposite to the a direction, so that the hot water amount increases and the hot water temperature decreases. It always produces hot water adjusted to the set temperature.

As is often done in restaurants, when the hot water tap 12 is squeezed and a small amount of water is poured into the sink 13 between the intermittent use of the hot water, the water flow rate of the water supply pipe 3 becomes smaller than that of the heat exchanger. The amount of water is less than the minimum operating flow rate, burner combustion of the heat exchanger 2 does not occur, and the differential pressure control valve 33 of the mixing unit 28 is closed, so that water flows into the heat exchanger 2. No matter what, the water passes through the branch water supply pipe 27, the mixing unit 28, and is discharged into the sink 13. Therefore, the heat exchanger 2 heated when the hot water is used is not rapidly cooled, so that dew condensation does not occur on the surface of the heat exchanger 2.

As described above, according to the water heater of the present embodiment, the differential pressure actuated valve 33 operates so that water passes through the heat exchanger 2 only when the heat exchanger 2 is heated by the burner combustion. As described above, cold water does not pass immediately after the heat exchanger 2 is heated, and dew condensation does not occur on the surface of the heat exchanger 2. Therefore, even if the hot water is used intermittently as described above, and even if it is used for the harsh use for commercial purposes such as discharging cold water little by little in the meantime, the service life can be extended compared to the conventional one. Therefore, the life of the water heater can be significantly extended.

Further, since the dew condensation prevention valve (differential pressure actuated valve) 33 and the thermo control valve 48 are compactly integrated in the mixing unit 28, they are smaller than separate installations, are easy to handle, and are easy to pipe. It will be easy. Furthermore, since the mixing unit 28 is provided on the outside of the hot water supply case 26, it can be attached to an existing hot water supply device or the like to prevent dew condensation of the heat exchanger and also to prevent corrosion, so that the application range is wide.

FIG. 3 shows a second embodiment of the present invention. This embodiment is characterized in that the dew condensation prevention valve is composed of a solenoid valve 34. The electromagnetic valve 34 is configured to have a valve body 44, and the hot water outlet 37a is used as a valve opening, and the valve body 44 is arranged opposite to the inlet side of the hot water outlet 37a. In addition, a flow sensor 35 is provided in the outlet passage 47 for detecting the amount of water in the device. That is, the flow sensor 35 detects the amount of water and sends the detection signal to a control device (not shown). The control device receives the detection signal and determines whether the water flow rate is equal to or higher than the minimum working flow rate of the appliance. The solenoid valve 34 which has received the ON signal is configured such that the valve body 44 is pulled up to open the hot water outlet 37a to allow the hot water to pass therethrough. Otherwise, the configuration is the same as that of the first embodiment.

In the second embodiment having such a configuration, when the flow sensor 35 detects the flow rate and detects a flow rate higher than the minimum working flow rate of the appliance, the solenoid valve 34 opens and the hot water outlet 37a opens. The operation is similar to the hot water supply operation of the first embodiment, except that the passage on the heat exchanger 2 side is opened. The operation of the thermo control valve 48 is also performed in the same manner as in the first embodiment, and hot water of a predetermined temperature is produced.

Therefore, the hot water supply apparatus according to the second embodiment can prevent dew condensation of the heat exchanger 2 as in the case of the first embodiment, and the hot water supply apparatus 1 has the same longevity and construction advantages. It is possible to achieve the desired effect.

The present invention is not limited to the above-mentioned embodiments, and various modes of implementation can be adopted. For example, in the first embodiment, the differential pressure actuated valve 33 is provided on the inlet side of the hot water passage 30. However, the hot water outlet 37a of the partition wall 5 may be provided as a valve opening, as long as it is on the hot water passage 30 route. There is no limitation on the place to install. Similarly, the solenoid valve 34 in the second embodiment can be provided at any place in the hot water passage 30.

Although the mixing unit 28 is provided outside the hot water supply case 26 in each of the embodiments, it may be incorporated in the hot water supply case 26.

Further, the springs 32 and 45 may be leaf springs, coil springs, or the like, and the type of the springs does not matter.

[0029]

[Effect of device]

 The mixing unit is equipped with a dew condensation prevention valve that opens the hot water passage when water exceeding the minimum operating flow rate of the equipment is supplied to the heat exchanger side, and closes otherwise. Water flows into the heat exchanger and is heated and discharged only when is heated by burner combustion, while when the amount of water supplied is less than the minimum operating flow rate of the heat exchanger, the passage on the heat exchanger side is Since water does not flow and flows out only through the branch water supply pipe, cold water does not pass through the heat exchanger, so that dew condensation does not occur on the surface of the heat exchanger and the service life of the water heater can be extended.

Further, in the case of a unit in which the dew condensation prevention valve and the thermo control valve are integrated as a unit as a mixing unit, it is smaller than the case where the dew condensation prevention valve and the thermo control valve are separately provided. It is easy to handle and piping work is easy. Furthermore, by connecting this mixing unit to an existing water heater or the like, it is possible to prevent dew condensation on the heat exchanger, so that the life of the water heater can be extended.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of a hot water supply device according to the present invention.

FIG. 2 is a detailed cross-sectional view of a mixing unit portion according to the first embodiment of the present invention.

FIG. 3 is a detailed cross-sectional view of the mixing unit portion of the second embodiment of the present invention.

FIG. 4 is a schematic diagram showing a structure of a conventional hot water supply device.

[Explanation of symbols]

 1 Hot water supply equipment 2 Heat exchanger 3 Water supply pipe 27 Branch water supply pipe 28 Mixing unit 29 Water passage 30 Hot water passage 33 Differential pressure operated valve (condensation prevention valve) 34 Electromagnetic valve (condensation prevention valve) 35 Flow sensor 42 Mixing chamber 47 Outlet passage 48 thermo control valve

Claims (4)

[Scope of utility model registration request] 1. A hot water supply device for heating water supplied from a water supply pipe through a heat exchanger and supplying hot water from the heat exchanger through the hot water supply pipe, wherein a branch water supply pipe is branched from the water supply pipe. A mixing unit is connected to the outlet of the branch water supply pipe and the outlet of the hot water supply pipe, and in the mixing unit, a water passage leading to the branch water supply pipe, a hot water passage leading to the hot water supply pipe, and water from the water passage and the hot water passage. There is a mixing chamber where the hot water from the unit joins, and an outlet passage that goes out from the mixing chamber.The hot water passage has a supply amount of water that exceeds the minimum operating flow rate of the equipment to the heat exchanger side. A hot water supply device, which is provided with a dew condensation preventing valve of a heat exchanger that opens a hot water passage when the hot water is opened. 2. The anti-condensation valve is a differential pressure actuated valve that opens the valve when the differential pressure between the upstream side and the downstream side of the valve becomes a pressure difference corresponding to a flow rate higher than the minimum working flow rate of the instrument. Hot water supply equipment according to 1. 3. A flow sensor is provided in the outlet passage of the mixing unit, and the dew condensation prevention valve provided in the hot water passage has a water supply amount at which water of a minimum working flow rate of the equipment or more is supplied to the heat exchanger side. The hot water supply device according to claim 1, wherein the hot water supply device is configured by an electromagnetic valve that opens the valve when the flow sensor detects the fact. 4. The mixing chamber of the mixing unit senses the temperature of the hot water in the mixing chamber to change the opening amount of the hot water passage and the opening amount of the water passage to adjust the mixing ratio of the hot water and the hot water. The hot water supply apparatus according to claim 1, 2 or 3, further comprising a thermo control valve for controlling the temperature to a set temperature.