JP2000356404A - Hot-water generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam injection type hot-water generating device without causing water hammer. SOLUTION: A hot-water generating device is provided with a water heater 20, mixing steam into water in a tank 19 to produce hot-water, and a steam supplying passage 34 for supplying steam S into the water heater 20. An air supplying passage 65 is concerted to the steam supplying passage 34 to supply air A into the water heater 20 through the air supplying passage 65 before starting the supply of the steam from the steam supplying passage 34 into the water heater 20. On the other hand, air is supplied into the water heater 20 through the air supplying passage 65 before stopping the supply of steam from the steam supplying passage 34 into the water heater 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water producing apparatus for producing hot water by utilizing excess steam generated in a plant such as a cogeneration system using a gas turbine.

[0002]

2. Description of the Related Art As a device for producing hot water to be supplied to a boiler or the like, a device for supplying steam to a heating coil,
Although there are electric heaters, etc., in order to heat a large volume of water in a short time, a hot water production apparatus of a steam direct injection type in which steam and water are mixed is effective (see Japanese Utility Model Application Laid-Open No. 63-179405). ). In the steam direct injection type hot water production equipment, an ejector type that sucks low-temperature hot water by the ejector effect to the jetted steam or a type with a silencer attached to the tip of the steam header are placed in the water tank. There is a method in which steam is injected into a steam header.

[0003]

However, in the case of a steam injection type hot water production apparatus in which a muffler is attached to the end of a steam header, the steam injected at the start of steam injection remains in the steam header. Water hammer is generated by mixing with water. Also, when the steam injection is stopped, part of the steam remaining in the steam header liquefies, causing a pressure drop,
Water penetrates into the steam header, and the water and the residual steam come into contact to generate a water hammer. Therefore, there is a problem that the life of the header and the tank is shortened by the impact of the water hammer.

[0004] The present invention has been made in view of the above problems, and has as its object to provide a hot water producing apparatus which does not generate a water hammer while being of a steam injection type.

[0005]

According to a first aspect of the present invention, there is provided a hot water producing apparatus comprising: a water heater for mixing hot water into water in a tank to generate hot water; A steam supply passage for supplying steam to the water heater; and an air supply passage connected to the steam supply passage and supplying air to the water heater before the start of steam supply from the steam supply passage to the water heater.

According to the hot water producing apparatus, before the start of the steam supply, the air is supplied from the air supply passage to the water heater via the steam supply passage, so that the steam header of the water heater or the steam supply passage close to the water heater is provided. Even if water remains in the tank, the remaining air is sent out into the tank by the supplied air, and even when the supply of steam is started, the steam and water come into contact in the steam header and steam supply passage in the water heater. Water hammer does not occur.

[0007] Further, the hot water producing apparatus according to a second aspect of the present invention, in the configuration of the first aspect, has a tank main valve for opening and closing a supply port to a tank of the steam supply passage, and the air supply passage is provided with a tank main valve. A controller which has an air opening / closing valve for opening / closing this passage, is connected to the steam supply passage upstream of the tank main valve, and further opens the tank main valve after opening the air opening / closing valve. Is provided.

[0008] According to the hot water producing apparatus, in the air supply before the start of the steam supply, the air opening / closing valve is first opened by the controller, the air is supplied to the tank base valve of the steam supply passage, and then the controller supplies the air. Since the tank main valve is opened and the air is further sent out from the tank main valve into the tank, the water remaining in the steam supply passage can be reliably sent into the tank before the start of the steam supply.

A third aspect of the present invention provides a hot water producing apparatus, comprising: a hot water heater for mixing hot water into water in a tank to generate hot water; a steam supply passage for supplying hot water to the hot water device;
An air supply passage connected to the steam supply passage for supplying air to the water heater before the supply of steam from the steam supply passage to the water heater is stopped.

[0010] According to the hot water producing apparatus, before the steam supply is stopped, the air is supplied from the air supply passage to the water heater via the steam supply passage, so that the steam header of the water heater or the steam supply passage close to the water heater is provided. Steam is sent out into the tank by the supplied air without remaining steam in the steam, and even if the supply of steam stops, the steam and water contact in the steam header and steam supply passage in the water heater Water hammer does not occur.

Further, the hot water producing apparatus according to a fourth aspect of the present invention, in the configuration of the third aspect, has a tank main valve for opening and closing a supply port to a tank of the steam supply path, and the air supply path is A controller which has an air opening / closing valve for opening and closing this passage, is connected to the steam supply passage upstream of the tank main valve, and further closes the tank main valve after opening the air opening / closing valve. Is provided.

According to the hot water producing apparatus, in the air supply before the stop of the steam supply, first, the air opening / closing valve is opened by the controller, and the air is supplied into the tank through the steam supply passage and the water heater. The steam in the steam supply passage is reliably sent out into the tank, and then the tank main valve is closed by the controller.Therefore, even if the air supply stops, the steam supply passage close to the steam header or the water heater of the water heater It is possible to reliably prevent water from entering the water.

[0013] Also, a hot water producing apparatus according to a fifth aspect of the present invention is a water heater that mixes steam with water in a tank to generate hot water, a steam supply passage that supplies steam to the water heater,
A temperature control valve that is provided in the steam supply passage and adjusts a steam supply amount to the water heater based on the temperature of the hot water in the tank; and a temperature control valve that is connected to the steam supply passage and before the opening operation of the temperature control valve starts. Or, an air supply passage for supplying air to the water heater before the closing operation is completed.

According to the hot water producing apparatus, the temperature of the hot water generated in the tank by the water heater is kept constant.
It is controlled by adjusting the steam supply amount by a temperature control valve.
Before the opening of the temperature control valve at which steam supply starts, air is supplied from the air supply passage to the water heater via the steam supply passage, so that the steam header of the water heater or the steam supply passage close to the water heater is provided. Even if water remains in the tank, the remaining air is sent out into the tank by the supplied air, and even when the supply of steam is started, the steam and water come into contact in the steam header and steam supply passage in the water heater. Water hammer does not occur. Furthermore, even before the closing operation of the temperature control valve in which the steam supply stops, air is supplied from the air supply passage to the water heater through the steam supply passage, so that the steam header of the water heater,
Alternatively, the steam is sent out into the tank by the supplied air without leaving steam in the steam supply passage near the water heater, and even if the supply of steam is stopped, the steam header or steam supply inside the water heater is stopped. There is no occurrence of water hammer due to contact between steam and water in the passage.

According to a sixth aspect of the present invention, in the hot water producing apparatus according to any one of the first to fifth aspects, a check valve for preventing a back flow of the hot water is provided in the steam supply passage. The air supply passage is connected to the steam supply passage downstream of the check valve.

According to the apparatus for producing hot water, it is possible to prevent hot water from flowing back upstream of the check valve in the steam supply passage.
Also, even if the hot water flows back to the check valve, the hot water is sent out into the tank by the supply of air from the air supply passage before the start of steam supply, so that the hot water and steam come into contact with each other and the water hammer It does not occur.

Further, a hot water producing apparatus according to a seventh aspect of the present invention includes a water heater for mixing the steam with water in the tank to generate hot water, a steam supply passage for supplying steam to the water heater,
A temperature control valve that is provided in the steam supply passage and adjusts a steam supply amount to the water heater based on the temperature of the hot water in the tank; and a bypass passage that bypasses the temperature control valve and passes a small amount of steam. Prepare.

According to the apparatus for producing hot water, the temperature of the hot water generated in the tank by the water heater is controlled to be constant by adjusting the steam supply amount by the temperature control valve, and the temperature control valve is closed. Even in the valve state, a small amount of steam continues to be supplied by the bypass passage, so that the supply of steam is not interrupted, and water is interrupted in the steam supply passage or the steam header in the water heater due to the interruption of steam supply. Hammer can be reliably prevented from occurring.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a hot water production device according to one embodiment of the present invention.
In FIG. 1, a gas turbine 1 compresses air by a compressor 2 and guides it to a combustor 3, injects gas fuel or liquid fuel into the combustor to burn it, and uses the high-temperature and high-pressure combustion gas to generate a turbine 4. Drive. The turbine 4 drives the compressor 2 and drives the generator 6 via the speed reducer 5. The generated power from the generator 6 is supplied to various power loads.

The exhaust gas G from the gas turbine 1 is guided to a waste heat boiler 7 and is discharged into the atmosphere through a chimney 8. The rotation axis of the gas turbine 1 is the bearing 1
It is supported on the casing by 3,14. When the gas turbine 1 is started, the compressor 9, the air tank 10, and the pressure reducing valve 11 leak oil from the air supply passage 12 provided in this order from the upstream side to the bearings 13 and 14 on the compressor 2 side and the turbine 4 side. Sealing air for prevention is supplied. That is, the air supply passage 12 is branched into two, and the seal air is supplied from one branch passage 15 to the bearing 13 of the compressor 2, and the seal air is supplied from the other branch passage 16 to the bearing 14 of the turbine 4. Check valves 17, 17 are provided in both branch passages 15, 16.
18 are provided, and after the start of the gas turbine 1,
Compressed air taken out from the middle stage of the compressor 2 passes through the branch passages 15 and 16 downstream of the check valves 17 and 18 and the bearings 13 and 1 of the compressor 2 and the turbine 4.
4 is supplied as seal air.

On the other hand, in the tank 19 for storing hot water,
A water heater 20 that mixes steam with water to generate hot water is provided. The water heater 20 comprises a tree-shaped steam header 21 for supplying steam, and a plurality of mufflers 22 attached to the steam openings distributed and opened in the branch portion 21a of the steam header 21.

FIG. 2 is a longitudinal sectional view showing an example of the structure of the muffler 22. As shown in FIG. The muffler 22 includes a housing 23 having a connection port 23a connected to the steam supply tube 32 of the header branch portion 21a.
4, a plurality of nozzle rings 26 externally fitted to the rod 25, and a plurality of disc-shaped plates 2 externally fitted to each nozzle ring 26.
7, a press plate 28 which is fitted to the distal end portion 25b of the rod 25 and sandwiches each of the nozzle rings 26 and the respective disc-shaped plates 27 with the housing 23; 2 and nut 2 for pressing holding plate 28 against housing 23
9 is provided.

The mixing chamber 30 is constituted by a pair of the disc-shaped plates 27 adjacent to each other, and a jet port 31 is formed on the outer peripheral side thereof. An opening 26a communicating with the mixing chamber 30 is formed in a peripheral wall of each nozzle ring 26, and a communication hole 26b is formed in an upper wall. Thereby, from the branch part 21a of the steam header 21 of FIG.
The steam S that has passed through the communication hole 26 b around the rod 25 of the silencer 22 in FIG. 2 is jetted into the mixing chamber 30 through the opening 26 a of the nozzle ring 26. Further, the mixing chamber 30 is tapered toward the outer peripheral side toward the ejection port 31, and the disc-shaped plate 27 constituting the mixing chamber 30 is kept at a low temperature by hot water stored in the tank 19. Therefore, the steam S condenses toward the outer periphery of the mixing chamber 30 to become hot water, and then jets into the tank 19. Therefore,
Since the steam S and the water do not come into contact in the tank 19, no water hammer is generated.

In FIG. 1, for the sake of simplicity, the water heater 20 is arranged so that its steam header 21 is in a vertical position in the tank 19; As shown in a perspective view, a steam header 21 extends parallel to the bottom of the tank 19 and is disposed.

A part of the steam S generated by the exhaust heat boiler 7 shown in FIG. 1 is injected from the intermediate pressure header 33 to the steam header 21 in the tank 19 via the steam supply passage 34. Also,
Another part of the steam S is supplied from the medium-pressure header 33 to the various loads 36 through other steam supply passages 35, where the liquefied water is returned to the tank 19.

In the middle of the steam supply passage 34, an automatic opening / closing valve 37, which closes when the temperature of the hot water in the tank 19 abnormally rises to a predetermined upper limit temperature, is adjusted upstream to regulate the supply amount of steam S. Temperature control valves 38 for maintaining the hot water in the tank 19 at a constant temperature are provided on the downstream side, respectively. A pressure reducing valve 39 is provided between the automatic on-off valve 37 and the temperature control valve 38. The controller 40 for controlling the entire equipment includes a PID temperature controller 41, and this PI
The D temperature controller 41 controls the opening of the temperature control valve 38 based on the temperature detected by the temperature sensor 42.

Between the upstream side and the downstream side of the steam supply passage 34 with the temperature control valve 38 interposed therebetween, a bypass passage 4 for passing a small amount of steam S bypassing the temperature control valve 38.
6, an on-off valve 47 is provided in the middle of the bypass passage 46.

Further, a check valve 48 for preventing a back flow of hot water from the tank 19 is provided downstream of the temperature control valve 38 in the steam supply passage 34. Further, downstream of the check valve 48, the steam supply passage 3
4 is provided with a tank main valve 49 for opening and closing a connection port to the tank 19.

A steam valve 50 and a pressure sensor 51 are provided in this order from the upstream side between the intermediate pressure header 33 and the automatic opening / closing valve 37 in the steam supply passage 34.

A drain passage 53 having a steam trap 54 in the middle thereof is connected to the bypass passage 46 on the upstream side of the on-off valve 47.
A bypass passage 55 is provided between the upstream side and the downstream side of the steam trap 54, and an on-off valve 56 is provided in the bypass passage 55.

The portion 34a of the steam supply passage 34 between the temperature control valve 38 and the check valve 48 is provided in the tank 1
9 so that the check valve 4
Even if the tube 8 is damaged, the hot water in the tank 19 is prevented from flowing back to the temperature control valve 38 side.

A drain passage 57 having a steam trap 58 in the middle thereof is connected to a portion of the steam supply passage 34 downstream of the high position 34a on the upstream side of the check valve 48 and immediately before the check valve. A bypass passage 59 is provided between the upstream side and the downstream side of the drain passage 57 with the steam trap 58 interposed therebetween.
9 is provided with an on-off valve 60.

A steam trap 62 is also provided between the check valve 48 and the tank main valve in the steam supply passage 34.
Is connected in the middle of the steam trap 62 in the drain passage 61, and a bypass passage 63 is provided in the drain passage 61. An on-off valve 64 is provided in the bypass passage 63. Have been.

Further, the drain passage 6 is provided between the check valve 48 and the tank main valve 49 in the steam supply passage 34.
An air supply passage 65 for supplying air A to the water heater 20 before the start of steam supply from the steam supply passage 34 to the water heater 20 and the stop of the steam supply from the steam supply passage 34 to the upstream side of the point of connection with the water heater 20 are connected. I have. The air supply passage 65 is branched from the downstream side of the pressure reducing valve 11 in the air supply passage 12 having the compressor 9 on the upstream side. The air supply passage 65 has an air opening / closing valve 6 for opening and closing the passage.
6 and a check valve 67 are provided in this order from the upstream side.

Next, the operation of the hot water producing apparatus will be described with reference to the flowcharts of FIGS. FIG. 4 shows an operation at the start of steam supply to the water heater 20, and FIG. 5 shows an operation at the stop of steam supply.

Prior to the start of steam supply to the water heater 20 in FIG. 1, the automatic opening / closing valve 37, the temperature control valve 38, and the tank base valve 49 in the steam supply passage 34 are closed, and are upstream of the automatic opening / closing valve 37. The steam valve 50 on the side is opened (step S1 in FIG. 4). Also, the drain passage 5
3, 57, 61 bypass passages 55, 59, 63
Each of the on-off valves 56, 60, 64 is opened (step S2). As a result, the drain is quickly discharged without passing through the steam traps 54, 58, and 62 before the supply of the steam having a large drain discharge amount.

The on-off valve 47 of the bypass passage 46 for bypassing the temperature control valve 38 in the steam supply passage 34 is also opened, and the automatic on-off valve 37 is opened (step S3).

In this state, when a start signal is input to the controller 40 (step S4), the water level in the tank 19 is higher than a predetermined level, or the steam pressure in the medium pressure header 33 is higher than a predetermined high pressure (for example, 4 kg / cm). ² ) is maintained for a certain period of time (for example, 10 seconds), and whether the water temperature of the tank 19 is maintained for a certain period of time at or below a predetermined upper limit is determined to be appropriate (step S5).

When the above conditions are satisfied, the air opening / closing valve 66 of the air supply passage 65 is opened.
6).

Subsequently, if the downstream side of the intermediate pressure header 33 in the steam supply passage 34 is sufficiently flushed by the bypass passage 55 in the drain passage 53 (for example, 30 seconds after the bypass passage 55 is opened), the bypass passage 55 The 55 on-off valve 56 is closed (step S8). As a result, the trap operation is started in the drain passage 53, and the intermediate pressure header 3 in the steam supply passage 34 is started.
Downstream of 3, the vapor pressure gradually increases.

Next, when the vapor pressure detected by the pressure sensor 51 on the downstream side of the intermediate pressure header 33 becomes higher than a predetermined value (for example, 8.0 kg / cm ² ) (step S9).
The tank main valve 49 on the downstream side in the steam supply passage 34 is opened (Step S10). As a result, the air A supplied from the air supply passage 65 is injected into the water heater 20 via a portion of the steam supply passage 34 downstream of the check valve 48. As a result, water remaining in the header 21 of the water heater 20 and in the steam supply passage 34 downstream of the check valve 48 is discharged into the tank 19 by the air A.

Next, the automatic opening / closing valve 37 in the steam supply passage 34 is opened (step S11). Thereby, the steam S generated in the exhaust heat boiler 7 of the gas turbine 1
Is supplied to the water heater 20 via the header 33 and the bypass passage 46 of the steam supply passage 34. At this time,
Since the steam S passes through the bypass passage 46, the supply amount of the steam S is smaller than in the normal operation.

When the portion from the steam valve 50 to the check valve 48 in the steam supply passage 34 is sufficiently flushed in this small amount of steam supply, the opening and closing valves 60 and 64 of the bypass passages 59 and 63 in the drain passages 57 and 61 are changed. The valve is closed (step S12). Thereby, the drain passage 5
At 7,61, the trap operation is started.

Next, the PID temperature controller 41 of the controller 40 starts operating, whereby the steam supply passage 34
PID control of the temperature control valve 38 is performed (step S13). That is, the PID temperature controller 41 controls the opening of the temperature control valve 38 based on the detection value of the temperature sensor 42 that detects the temperature of the hot water in the tank 19, and adjusts the steam supply amount to the water heater 20. And the tank 1
Keep the temperature of the hot water in 9 constant.

At this time, the air A is supplied from the air supply passage 65 to the steam supply passage 34 downstream of the check valve 48.
In this case, the steam pressure is sufficiently higher than the supply air pressure, and the steam S is supplied to the water heater 20 overcoming the supply of the air A. Further, the water remaining in the water heater 20 and the steam supply passage 34 downstream of the check valve 48 is previously removed by the air A as described above.
0 in the steam header 21 and the steam supply passage 34,
The occurrence of water hammer due to contact between the supplied steam S and the residual water can be reliably prevented.

Next, the air on-off valve 6 in the air supply passage 65
6 is closed (step S14). Thereby, the removal of the residual water in the water heater 20 and the steam supply passage 34 before the start of the steam supply is completed, and thereafter the automatic temperature control by the temperature control valve 38 is performed. The hot water stored in the tank 19 passes through the hot water supply passage 68, for example, into the gas turbine 1
Is supplied to the waste heat boiler 7 and is used for generating steam.
When a level sensor (not shown) detects that the water level in the tank 19 has fallen below the predetermined level, water is supplied to the tank 19 from the water supply passage 69.

From the automatic temperature control state, the supply of steam is stopped in the following procedure. When a stop signal is input to the controller 40 (step R1 in FIG. 5), it is confirmed whether or not the temperature control valve 38 in the steam supply passage 34 is open (step R2). If so, the valve is closed (step R3). Even if the temperature control valve 38 is closed in this way, the temperature control valve 3
Since the bypass passage 46 that bypasses 8 is open, a small amount of steam S continues to be supplied to the water heater 20 at this time as well.

Next, the air on-off valve 6 in the air supply passage 65
The valve 6 is opened for a predetermined time (for example, 30 seconds) (step R4). As a result, the air A is injected into the water heater 20 from the air supply passage 65 through a portion of the steam supply passage 34 downstream of the check valve 48. That is, at this time, since the amount of steam flowing through the steam supply passage 34 is small, the supplied air pressure overcomes the steam pressure, and the water heater 20
Air can be injected into the device. As a result, the steam supply passage 6
The steam S remaining in the portion downstream of the check valve 48 and the water heater 20 in 5 is discharged into the tank 19.

Next, the automatic open / close valve 37 in the steam supply passage 34 is closed (step R5). This allows
Steam supply to the water heater 20 is stopped. Next, the tank main valve 49 on the downstream side of the steam supply passage 34 is closed (step R6), and the air opening / closing valve 66 in the air supply passage 65 is closed (step R7). Thereby, the supply of the air A to the water heater 20 ends. At this time, the portion of the steam supply passage 34 downstream of the tank main valve 49 and the inside of the water heater 20 are filled with the air A, and the steam S does not remain. As a result, it is possible to reliably prevent a situation in which the hot water enters the steam header 21 of the water heater 20 and the steam supply passage 34 and comes into contact with the residual steam to generate a water hammer. Finally, the upstream steam valve 5 in the steam supply passage 34
0 is closed (step R8), and the steam supply is completely stopped.

As described above, in the water temperature producing apparatus, it is possible to reliably prevent the occurrence of water hammer at the start of steam supply or at the stop of steam supply. In general plant equipment, since the compressor 9 is usually provided as an air supply source, there is no need to install special equipment for air supply, and the occurrence of water hammer can be prevented at low cost.

In the above embodiment, the automatic on-off valve 37
Although the on / off valves other than the temperature control valve 38 are automatically opened and closed by the controller 40, these may be manually opened and closed.

In the above embodiment, the steam supply passage 3
4, the temperature control valve 3
8 is provided,
Even when the temperature control valve 38 is fully closed during automatic temperature control, a small amount of steam is supplied through the bypass passage 46, and when the temperature control valve 38 is fully closed or subsequently opened, Although it is possible to prevent the occurrence of water hammer due to the contact between the steam S and the water in the water heater 20 and the steam supply passage 34, the bypass passage 46 is omitted, and the temperature control valve 38 is omitted.
At the start of the opening operation or at the end of the closing operation,
The generation of water hammer may be prevented by the air supply from the air supply unit 5.

That is, in this case, the temperature control valve 38
Is operated to the valve closing side, and immediately before the end of the closing operation when the opening degree reaches a predetermined lower limit value, the air opening / closing valve 66 in the air supply passage 65 is opened, and the air A is supplied to the water heater 20. Inject. Thereby, before the steam supply is stopped, the steam S remaining in the downstream portion and the water heater 20 of the steam supply passage 34 from the check valve 48 can be discharged by the supply air A. When the temperature of the hot water in the tank 19 detected by the temperature sensor 42 drops below a predetermined value lower than the target value while the temperature control valve 38 is fully closed, the air opening / closing valve 66 in the air supply passage 65 is opened. The valve A is injected into the water heater 20 to inject the air A, and the control of the temperature control valve 38 is restarted after a predetermined time measured by a timer has elapsed from the start of the air supply. Thus, before the steam supply is restarted, that is, before the opening operation of the temperature control valve is started, the residual water in the portion of the steam supply passage 34 downstream from the check valve 48 and in the water heater 20 is supplied to the supply air. A can be discharged.

[0054]

As described above, according to the hot water producing apparatus of the first aspect of the present invention, air is supplied to the water heater before the start of steam supply from the steam supply passage to the water heater by being connected to the steam supply passage. Even if water remains in the water heater or the steam supply passage close to the water heater before the start of steam supply, residual water is sent out into the tank by the supplied air, By the start of the supply, there is no occurrence of water hammer due to the contact between the steam and the water in the steam header and the steam supply passage in the water heater.

According to the third aspect of the present invention, the air supply passage connected to the steam supply passage for supplying air to the water heater before the steam supply from the steam supply passage to the water heater is stopped. The steam supplied to the tank by the air supplied before the steam supply was stopped before the steam supply was stopped.Even if the supply of steam was stopped, steam and water would be generated in the steam header and steam supply passage in the water heater. Water hammer does not occur upon contact.

The hot water producing apparatus according to claim 5 is
Since the air supply passage for supplying air to the water heater before the start of the opening operation of the temperature control valve or the end of the closing operation of the temperature control valve is provided, before the start of the opening operation of the temperature control valve at which steam supply starts, the steam is supplied from the air supply passage. Since air is supplied to the water heater through the supply passage, even if water remains in the steam header of the water heater or in the steam supply passage close to the water heater, residual water is sent out into the tank by the supplied air, Even when the supply of steam is started, there is no occurrence of water hammer due to contact between steam and water in the water heater or the steam supply passage. Further, before the closing operation of the temperature control valve at which the steam supply is stopped, the air is supplied from the air supply passage to the water heater through the steam supply passage, so that the steam supply close to the steam header or the water heater of the water heater is provided. The steam is sent out into the tank by the supplied air without the steam remaining in the passage, and even if the supply of steam is stopped, the steam and water will be generated in the steam header and steam supply passage in the water heater. Water hammer does not occur upon contact.

The hot water producing apparatus according to the invention of claim 6 is
Since a bypass passage for bypassing the temperature control valve and passing a small amount of steam is provided, even if the temperature control valve is closed, a small amount of steam is continuously supplied by the bypass passage. As a result, it is possible to reliably prevent water hammer from being generated in the steam header in the steam supply passage or the water heater.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hot water production device according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a muffler constituting a water heater in the hot water producing apparatus.

FIG. 3 is a perspective view showing an arrangement configuration of a water heater in the apparatus for producing hot water.

FIG. 4 is a flowchart showing a procedure of a starting operation of the hot water producing apparatus.

FIG. 5 is a flowchart showing a procedure of a stop operation of the hot water producing apparatus.

[Explanation of symbols]

19: tank, 20: water heater, 21: steam header, 34
... Steam supply passage, 38 ... Temperature control valve, 40 ... Controller, 46 ... Bypass passage, 48 ... Check valve, 49 ... Tank base valve, 65 ... Air supply passage, 66 ... Air open / close valve, A ... Air, S ... steam

Claims (7)

[Claims] 1. A water heater that mixes steam with water in a tank to generate hot water, a steam supply passage that supplies steam to the water heater, and a water heater that is connected to the steam supply passage and passes through the steam supply passage. A hot water production device comprising: an air supply passage that supplies air to a water heater before starting steam supply to the water heater. 2. The tank according to claim 1, further comprising: a tank base valve for opening and closing a supply port to the tank of the steam supply passage, wherein the air supply passage has an air on-off valve for opening and closing the passage. A hot water production device connected to the steam supply passage upstream of a main valve, and further comprising a controller that opens the tank main valve after opening the air on-off valve. 3. A water heater that mixes steam with water in a tank to generate hot water, a steam supply passage that supplies steam to the water heater, and a water heater that is connected to the steam supply passage and passes through the steam supply passage. An air supply passage for supplying air to a water heater before the supply of steam to the heater is stopped. 4. The tank according to claim 3, further comprising: a tank base valve for opening and closing a supply port to the tank of the steam supply passage, wherein the air supply passage has an air on-off valve for opening and closing this passage, A hot water production device connected to the steam supply passage upstream of the main valve, and further comprising a controller that opens the air on-off valve and then closes the tank main valve. 5. A water heater that mixes steam with water in a tank to generate hot water, a steam supply passage that supplies steam to the water heater, and a temperature of the hot water in the tank that is provided in the steam supply passage. A temperature control valve that controls the amount of steam supplied to the water heater based on the temperature control valve, and is connected to the steam supply passage to supply air to the water heater before the start of the opening operation or before the end of the closing operation of the temperature control valve. A hot water production device having an air supply passage. 6. The steam supply passage according to claim 1, further comprising a check valve provided in the steam supply passage for preventing a backflow of hot water, wherein the air supply passage is provided downstream of the check valve in the steam supply passage. Hot water production equipment to which the supply passage is connected. 7. A water heater for mixing the steam with water in the tank to generate hot water, a steam supply passage for supplying steam to the water heater, a temperature of the hot water in the tank provided in the steam supply passage. A hot water production apparatus comprising: a temperature control valve that controls a steam supply amount to a water heater based on the temperature control valve; and a bypass passage that allows a small amount of steam to pass through the temperature control valve.