JP3165754B2 - Hot water production equipment - Google Patents

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 mixing steam and water.

[0002]

2. Description of the Related Art Conventionally, there is a hot water producing apparatus for producing hot water by mixing steam and water. Such a hot water production apparatus is excellent in thermal efficiency because the temperature of water is raised using the latent heat of steam. An example of this type of hot water production apparatus is shown in FIGS.

In FIG. 5, a tank 1 has a floating valve 2. The floating valve 2 keeps the water level of the tank 1 constant, and controls the flow rate of the cold water C from the water supply pipe 3. The tank 1 is provided in a circulation path 4. The circulation path 4 is provided with a pump 5 for taking out water W from the tank 1 and supplying the water W to the mixer 20 via the supply pipe 13. The mixer 20 mixes the water W with the steam S and discharges the hot water H into the discharge pipe 10.
Discharge from. The temperature of the hot water in the mixer 20 is detected by the temperature detector 6, and based on the detected temperature, the temperature control device 7 adjusts the opening of the regulating valve 8 and flows into the mixer 20 from the steam pipe 9. The predetermined temperature is maintained by controlling the amount of steam generated. An outlet pipe 11 for extracting a part of the discharged hot water H to the user load side branches from the discharge pipe 10.
The distal end portion 12 of the discharge pipe 10 is inserted into the tank 1, and surplus hot water H after being taken out to the user load side is collected in the tank 1.

In FIG. 6, the mixer 20 has a mixing chamber 21 for mixing steam S and water W.
1, a steam blowing pipe 24 having a number of small holes 23 is inserted. The steam blowing pipe 24 blows out the steam S from the steam pipe 9 into the mixing chamber 21 through the small holes 23 in a bubble state. The water W is mixed with the steam S and heated to become hot water H, which is discharged from the discharge pipe 10 in FIG.

[0005]

By the way, the amount of hot water H taken out to the user load side (hereinafter referred to as "usage amount") varies greatly depending on time of day and the like. Since it is necessary to maintain the pressure of the taken-out hot water H at a predetermined pressure or higher, conventionally, the discharge amount of the pump 5 is set to an amount corresponding to the maximum usage amount. Therefore, when the usage amount is small, the water pressure in the mixer 20 increases. On the other hand, as described above, since the amount of steam S supplied to the mixer 20 is changed to maintain the temperature of the hot water H at a predetermined temperature, when the temperature of the hot water H increases, the flow rate of the steam S decreases. And therefore the vapor pressure in the mixer 20 of FIG. 6 decreases.

As described above, when the steam pressure is lowered and the water pressure is increased, the water pressure exceeds the steam pressure, so that the water W flows backward from the small holes 23 into the steam blow-out pipe 24. Therefore, since the mixing of the water W and the steam S is performed in the steam blowing pipe 24, the contact area between the water W and the steam S decreases, and as a result, the thermal efficiency decreases.

Further, as described above, when the water S is mixed in the steam blow-out pipe 24, the steam S is rapidly absorbed by the water W, so that a water hammer is generated. Therefore, the pipelines and valves such as the steam blowing pipe 24 are easily damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a hot water producing apparatus capable of improving thermal efficiency and preventing damage to pipelines and valves.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a pressure detector for detecting a pressure of water pressurized by a pump, and a pressure detector for detecting the pressure of the water. A pump control device for controlling the discharge amount of the pump based on the detected pressure. According to the first aspect of the present invention, since the discharge amount of the pump is controlled based on the pressure of the water pressurized by the pump, for example, by keeping the water pressure at a constant value, the water pressure is kept lower than the vapor pressure. be able to.

According to a second aspect of the present invention, there is provided a flow rate detector for detecting a flow rate of hot water taken out to the user load side or a flow rate of excess hot water, and a discharge amount of the pump based on the flow rate detected by the flow rate detector. And a pump control device for controlling the pressure. In the invention of claim 2, when the discharge amount of the pump is controlled based on the used amount, for example, by making the discharge amount of the pump proportional to the used amount, when the hot water is not taken out or when the used amount is small. , The water pressure will be lower.
On the other hand, when the discharge rate of the pump is controlled based on the flow rate of the surplus hot water, for example, by keeping the flow rate of the surplus hot water at a constant value, when not in use or when the usage amount is small, the water pressure is low. Become.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment. In FIG. 1, in the first embodiment, a pressure detector 14 is provided near a mixer 20 in a discharge pipe 10. The pressure detector 14 detects a pressure in the vicinity of the mixer 20 in the discharge pipe 10 and outputs a pressure signal p obtained by converting the pressure into a voltage to the pump control device 15. The pump control device 15 controls the discharge amount of the pump 5 based on the pressure detected by the pressure detector 14. That is, in the case of this embodiment, the pump control device 15 receives the pressure signal p, converts the voltage into a frequency, and outputs the frequency signal r to the pump 5, so that the detected pressure becomes a predetermined pressure, for example. Pump 5
To control the number of revolutions. The predetermined pressure is, for example,
In an unused state in which the hot water H is not taken out from the outlet pipe 11, the detected pressure is set to a value slightly lower than the steam pressure at that time. The other configuration is the same as that of the conventional example, and the same or corresponding portions are denoted by the same reference characters and detailed description thereof will not be repeated.

In the above configuration, when the amount of hot water H used increases, the water pressure in the discharge pipe 10 starts to decrease, and the pressure detector 14 detects this, and the pump control device 1
5, the discharge amount of the pump 5 is increased, and the pressure in the discharge pipe 10 is maintained at a predetermined pressure. Therefore, the discharge pressure from the discharge pipe 11 is also maintained in a predetermined range.

On the other hand, when the usage amount of the hot water H decreases, the detected pressure of the discharge pipe 10 starts to increase. However, since the discharge amount of the pump 5 is suppressed by the pump control device 15, the supply pipe 1
3 is maintained in a predetermined range lower than the vapor pressure. Therefore, the mixer 20 communicating with the discharge pipe 10 of FIG.
Since the water pressure in the inside is also lower than the steam pressure in the steam blow-out pipe 24, there is no possibility that the water W flows backward from the small hole 23 into the steam blow-out pipe 24.

Therefore, since the steam S blown out from the small holes 23 is mixed with the water W in a bubble state, the contact area between the water W and the steam S is large, so that the thermal efficiency is improved. Further, since the steam S is mixed with the water W in a bubble state, the water hammer can be prevented, and there is no risk of damaging the pipeline and the valve.

In the above embodiment, the pressure detector 14 is provided on the discharge pipe 10, but the pressure detector 14 is not necessarily provided on the discharge pipe 10. That is, the pressure detector 1
4 may be provided, for example, in the vicinity of the mixer 20 in the supply pipe 13 or in the mixing chamber 21. In other words, the detector 4 detects the pressure of the water W or the hot water H pressurized by the pump 5 in FIG. I just need.

In the above embodiment, the pressure detected by the pressure detector 14 is maintained at a constant predetermined pressure. However, it is not always necessary to maintain the pressure detected at a constant level. One example is shown in the second embodiment in FIG. In FIG. 3, in this embodiment, a pressure detector 16 for detecting a steam pressure is provided on a secondary side 9a downstream of the regulating valve 8 in the steam pipe 9. This pressure detector 16
The pressure of the steam S on the secondary side 9a is detected and the pressure signal p
s is output to the pump controller 15. Pump control device 1
5 compares the pressures from the two pressure detectors 14, 16 and generates a frequency signal r so that the water pressure is lower than the vapor pressure.
Is output to the pump 5 to control the rotation speed of the pump 5.
Other configurations are the same as those of the first embodiment, and the same or corresponding portions are denoted by the same reference characters, and description and illustration are omitted.

In each of the above embodiments, the pump 5 is controlled by detecting the pressure of the water W and H pressurized by the pump 5. In the present invention, the amount of use is detected and the amount of use is determined. , The pump 5 may be controlled. An example of this is shown in the third embodiment in FIG.

In FIG. 4, in this embodiment, the discharge pipe 1
The flow detector 17 is provided at the branch 10a at 0. This flow rate detector 17 is used for
The flow rate of the hot water H taken out from 1 is detected, and this value is output to the pump control device 15 as a flow rate signal q. The pump control device 15 receives the flow rate signal q and outputs a frequency signal r to the pump 5, thereby increasing or decreasing the number of times of the pump 5 in accordance with an increase or decrease in the usage amount, and controlling the discharge amount from the pump 5. . The other configuration is the same as that of the conventional example, and the same or corresponding portions are denoted by the same reference characters, and detailed description and illustration thereof are omitted.

In the above configuration, when the amount of use decreases, the pressure gradient in the circulation path 4 decreases, so that the water pressure in the mixer 20 starts to increase while the flow rate of steam in the mixer 20 decreases. The vapor pressure starts to drop.
However, when the used amount is reduced, the detected flow rate is reduced, and the discharge amount of the pump 5 is immediately reduced, so that the water pressure in the mixer 20 does not increase, and therefore, the above-described backflow can be prevented.

By the way, in the third embodiment, the branch 1
Although the flow rate detector 17 is provided at 0a to directly detect the usage amount, in the present invention, the usage amount may be detected indirectly.
That is, the flow rate detector 17 is provided at the distal end portion 12 of the discharge pipe 10 to detect the flow rate of the surplus hot water H, and when the flow rate of the surplus hot water H decreases below a predetermined amount, the discharge of the pump 5 When the amount is increased, and the flow rate of the surplus hot water H is larger than a predetermined amount, the discharge amount of the pump 5 may be decreased.

[0021]

As described above, according to the present invention, since the water pressure in the mixer can be kept lower than the vapor pressure, the vapor in a bubble state can be mixed with the water. Therefore, the thermal efficiency can be improved, and the water hammer can be prevented, so that damage to the pipeline and the valve can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hot water producing apparatus showing a first embodiment of the present invention.

FIG. 2 is a schematic front view of a mixer.

FIG. 3 is a schematic configuration diagram of a hot water producing apparatus showing a second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a hot water producing apparatus showing a third embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a conventional hot water production device.

FIG. 6 is a schematic front view of the mixer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... tank, 5 ... pump, 8 ... regulating valve, 14 ... pressure detector, 15 ... pump controller, 17 ... flow detector, 20 ...
Mixer, W: water, H: warm water (water), S: steam.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-54552 (JP, A) JP-A-6-42811 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24H 1/10

Claims (2)

(57) [Claims] 1. A mixer for mixing water and steam to discharge hot water, a tank in which a surplus of the discharged hot water after being taken out to a user load side is returned, and water taken out of the tank is taken out of the tank. A hot water production device comprising: a pump to be supplied to the mixer; and an adjusting valve for controlling a flow rate of steam flowing into the mixer so that the temperature of the hot water heated by the mixer becomes a predetermined temperature. Hot water production, comprising: a pressure detector for detecting a pressure of pressurized water; and a pump control device for controlling a discharge amount of the pump based on a pressure detected by the pressure detector. apparatus. 2. A mixer that mixes water and steam to discharge hot water, a tank in which a surplus of the discharged hot water after being taken out to the user load side is returned, and water is taken out from this tank to take out the hot water. A hot water production apparatus comprising: a pump to be supplied to the mixer; and an adjustment valve for controlling a flow rate of steam flowing into the mixer so that the hot water heated by the mixer has a predetermined temperature. A flow detector for detecting a flow rate of hot water taken out or a flow rate of surplus hot water, and a pump control device for controlling a discharge amount of the pump based on the flow rate detected by the flow detector. A hot water production device characterized by the following.