JPH07109320B2 - Direct contact hot water heater - Google Patents

Description

TECHNICAL FIELD The present invention relates to a direct contact hot water heater.

BACKGROUND ART A typical prior art direct contact hot water heater forms an endothermic chamber above a combustion chamber and sprinkles water from above the endothermic chamber toward an endothermic material filled in the endothermic chamber. And a combustion gas such as a gas provided in the combustion chamber from a burner are brought into direct contact with each other to perform heat exchange and heating.

Problems to be Solved by the Invention In such a prior art, since watering to the heat absorbing material is stopped and combustion of the burner is stopped at the same time, water droplets stay on the heat absorbing material. For this reason, various bacteria and algae may proliferate especially in the summer, which is not preferable in terms of hygiene.

An object of the present invention is to provide a direct contact hot water heater capable of supplying sanitary hot water.

Means for Solving the Problems The present invention forms a combustion chamber provided with a burner in a tubular body, forms an endothermic chamber filled with an endothermic material above the combustion chamber, and removes water from above the endothermic chamber. A direct contact hot water heater that sprinkles water and makes direct contact between the water and the combustion gas from the combustion chamber, characterized by maintaining the combustion state in the combustion chamber for a short time after stopping the sprinkling when the operation is stopped. It is a direct contact type hot water heater.

Operation According to the present invention, the combustion chamber provided with the burner is formed in the cylindrical main body, and the heat absorbing chamber filled with the heat absorbing material is formed above the combustion chamber. Water is sprayed from above the heat absorbing chamber toward the heat absorbing material, and the water and the combustion gas from the combustion chamber are brought into direct contact with each other to perform heat exchange, whereby hot water can be obtained.

When such a warm water heater is not operated for a relatively long period of time, after stopping the water sprinkling, the combustion state in the combustion chamber is maintained for a predetermined short time, the heat absorbing material is put into an empty state, and the water droplets retained in the heat absorbing material are kept. Hot air drying is carried out.

Embodiment FIG. 1 shows a direct contact type hot water heater 1 according to an embodiment of the present invention.
FIG. A hot water storage portion 3 is formed at the lowermost portion of the heater body 2 formed in a right cylindrical shape. This hot water storage unit 3
A combustion chamber 4 is formed above. In the combustion chamber 4, combustion is performed by the burner 5 attached to the side portion of the heater body 2. Combustion air is sent under pressure from the centrifugal blower 6 to the burner 5, and fuel gas is supplied from the pipe 7 through the fuel cutoff valve 18. The combustion exhaust gas from the burner 5 is exhausted to the outside through an exhaust pipe 8 above the heater body 2. A heat absorbing chamber 9 is formed above the combustion chamber 4, and the heat absorbing chamber 9 is partitioned from the combustion chamber 4 by a perforated plate 10 made of a material having heat resistance such as metal.
The endothermic material 11 is filled on the upper part 10. A water sprinkling chamber 12 is formed above the heat absorbing chamber 9, and in this water sprinkling chamber 12, water supplied from a pipe line 13 is passed from a water supply nozzle 15 via a solenoid valve 17 and an electric flow control valve 14. Water is sprayed toward the heat absorbing material 11. A cooling pipe 16 is provided immediately above the perforated plate 10. Water is supplied to the cooling pipe 16 from the electric flow control valve 14 to cool the perforated plate 10.

The electrically operated flow control valve 14 can continuously and continuously adjust the flow rate of water through the conduit 13 in response to an output from a control means (not shown).

The burner 5 is a so-called blast burner, and the combustion air pressure-fed from the centrifugal blower 6 is discharged from the air chamber 21 into the straightening vane.
It is uniformly supplied to the burner body 23 via 22. The burner 5 is provided with a pilot burner 24. While the hot water heater 1 is in operation, the pilot burner 24
Is igniting a pilot fire, and the centrifugal blower 6 is operating. Therefore, the opening of the fuel cutoff valve 13 immediately ignites the burner body 23. In this way, the burner 5 is in a combustion state in which the pilot burner 24 and the burner body 23 are ignited. The fuel cutoff valve 18 is the same as the electric flow control valve described above.
It is controlled by control means (not shown). Since a constant fuel gas is always supplied during combustion of the burner 5, the amount of heat generated by the combustion of the burner 5 is constant. Burner 5
In addition to gas, the fuel may be a liquid fuel such as petroleum, or a solid fuel such as coal.

The perforated plate 10 has a shape having a slope for forming a water film on the upper and lower surfaces of the top part 10a to allow water to flow down the entire circumference, that is, a shape such as a cone shape or a pyramid shape. A large number of holes 10b capable of forming a water film are formed.

The water supplied from the pipe 13 is sprinkled from the water supply nozzle 15 and heat-exchanges with the combustion gas from the combustion chamber 4 in the heat absorbing material 11 by direct contact with the bottom plate.
The falling pipe 26 formed at 25 flows into the hot water storage unit 3 and is stored therein. The lower end of the falling pipe 26 is formed above the bottom plate 40 by a height of 1.

The hot water stored in the hot water storage unit 3 is taken into the pump 32 from the pipe 31, the pipe 48 passes through the flow rate control mechanism 33, and the hot water supply pipe 34.
Is supplied to. The pump 32 rotates at a constant speed and the hot water supply pipe 34
The flow rate of the warm water supplied to the
It is adjusted by the flow rate control mechanism 33. A plurality of currans 34 are attached to the tip of the hot water supply pipe 34 (in FIG. 1,
Only one of those Callan 35 is shown).

By providing the hot water storage unit 3 in this way, hot water can be stably supplied even with a relatively large amount of hot water supply. Further, at the start of hot water supply and when the amount of hot water supply is small, high-temperature hot water is not supplied, while when the amount of hot water supply is large, the temperature of the hot water does not drop, thus making it possible to achieve high water content regardless of the amount of hot water supplied. , You will always be able to obtain the desired constant temperature hot water. Further, the flow rate of the water sprinkled on the heat absorbing material 11 is larger than the hot water supply amount when a small number of the plurality of currans 35 are opened, and therefore, even when the small number of currans 35 are opened, the combustion chamber 4 and There is no possibility that the heat absorbing chamber 9 will become excessively high. Furthermore,
For example, the burner body 23 does not frequently repeat ignition and extinguishing in response to the opening / closing operation of one calan 35, and the burner 5 can be stably burned.

The pump 32 may be, for example, a centrifugal type or an axial flow type.
The upper end of the intake port 46 of the pipeline 31 that supplies hot water to the pump 32 is
A temperature detecting element 47 is formed at a height l2 from the bottom plate 40 and near the water intake port 46.

FIG. 2 is a sectional view of the vicinity of the flow rate control mechanism 33. pump
The hot water discharged from 32 is guided to the valve chamber 51 of the flow rate control mechanism 33 from the pipe line 48. The force acting on the float 52 floated in warm water in the hot water storage unit 3 is transmitted to the lever 60. lever
The pin 60 is fixed to one end of the lever 54 by the pin 61.
The lever 54 is swingably supported by a bracket 53 attached to the wall surface of the hot water storage unit 3 by a pin 62. The other end of the lever 54 supports the valve rod 55 by a pin 63 so that the valve rod 55 can be angularly displaced. The force thus transmitted to the lever 60 is applied to the valve body 56.
Be transmitted to. The valve body 56 is spring-biased by a spring 57 in a direction to be seated on the valve seat 58.

Therefore, when the water level in the hot water storage unit 3 is lowered, the float
52 descends, the flow passage cross-sectional area of the valve hole 59 becomes smaller, and the hot water supply pipe
The flow rate of hot water supplied to 34 becomes smaller. Also the hot water storage part 3
When the water level is high, the float 52 rises, the flow passage cross-sectional area of the valve hole 59 increases, and the flow rate of hot water supplied to the hot water supply pipe 34 increases. As described above, by the flow rate control mechanism 33, the flow rate corresponding to the amount of hot water stored in the hot water storage unit 3, that is, the same flow rate as the amount of water sprayed to the heat absorbing material 11, is the upper limit of the hot water supply flow rate, and the hot water supply pipe 34 Since the hot water is supplied to the hot water, the water level of the hot water storage unit 3 does not suddenly decrease, and the hot water can be continuously used. In addition, the flow rate control mechanism 33
When the water level of the hot water storage unit 3 becomes lower than the third water level l3, the valve body 56 of the valve seat 56 is seated on the valve seat 53, and the supply of hot water to the hot water supply pipe 34 is stopped. At a water level above the third water level l3, hot water is supplied at a flow rate below the upper limit.

An overflow pipe 36 is formed in the hot water storage unit 3, and when the hot water in the hot water storage unit 3 reaches a water level exceeding the overflow pipe 36, the hot water is discharged from the overflow pipe 36 to the outside via a drain pipe 43. To be done. On the wall surface of the hot water storage unit 3, water level detecting elements 37 to 39 which are water level detecting means.
Is installed. The water level detecting element 37 provided above the hot water storage unit 3 detects the first water level H, the water level detecting element 38 provided below the water level detecting element 37 detects the second water level M, and below the water level detecting element 33. The water level detecting element 39 provided detects the lower limit value L of the water level. These water level detection elements 37-39
The output of is given to the control means. When the hot water in the hot water storage unit 3 is used and the water level drops to the second water level M, the control means causes the sprinkling and the burner 5 until the water level is restored to the first water level H.
Is burned. The water level detection elements 37 to 39 are, for example,
It may be one that detects whether or not it is submerged by the permittivity of water and air, or one that detects whether or not one is submerged by using the conductivity of water. .

A pipe 41 is connected to the bottom plate 40 of the hot water storage unit 3, and the pipe 41 is connected to a drain pipe 43 via a drain valve 42. Therefore, when it is not used for a long period of time, by opening the drain valve 42, all the water in the hot water storage part 3 can be discharged. The bottom plate 40 of the hot water storage unit 3 is also formed with a rising pipe 44 having a height of l4. This rising pipe 44 is a solenoid valve that can be opened and closed.
It is connected to the drain pipe 43 via 45. Water level H, M described above,
The heights 1, 12, and 4 and the lower limit value L are selected by the following equation.

1 <l2 <L ≦ 4 <M <H (1) Therefore, by opening the solenoid valve 45, the water level of the hot water storage unit 3 is lowered to the height l4, but the lower end of the falling pipe 26 is Since the portion is formed at a position of height 1 lower than this height l4, water sealing of the combustion chamber 4 is achieved, and combustion gas from the combustion chamber 4 is prevented from entering the hot water storage portion 3. Instead of the drain valve 42, the electromagnetic valve 45 may be provided in the conduit 41 so that all the hot water in the hot water storage unit 3 is discharged by opening the electromagnetic valve 45. In addition, the intake port 46 of the pipeline 31 has a height of
Since it is formed at a position with a height l2 lower than that, air will not be caught in the hot water supplied to the hot water supply pipe 34.

Since the height l3 is selected to be the lower limit value L or more, the flow rate control mechanism 33
When it is detected by the water level detection element 39 that the water level has dropped below the lower limit value L due to an abnormality or the like of the pump 32,
Operation is stopped and the water seal is maintained.

In the hot water heater 1 configured in this manner, the water to be heated has a structure that is in direct contact with the combustion gas in the process of flowing from the heat absorbing chamber above the combustion chamber 4 to the hot water storage unit 3 below, so that the thermal efficiency is high. Is very good, and unlike the structure of a conventional boiler or the like that obtains hot water in a closed container, since it has a structure that heats water under atmospheric pressure, it can be easily used in general households. Furthermore, the hot water obtained is
As it is warm water with dissolved oxygen degassed and good for rust prevention, and since carbon dioxide gas contained in the combustion gas is taken in, when used as a bath, normal tap water such as fatigue recovery can be used as it is. It has the effect that hot water heated in a bath pot does not have.

Moreover, in the heating process of the hot water, the perforated plate 10 has slopes on both upper and lower surfaces thereof to allow water to flow down the entire circumference, and the holes 10b provided on the slopes are formed by surface tension. A porous film that can form a water film
Since the endothermic material 11 is arranged so that the endothermic material 11 does not project from the lower surface of 10, the water sprinkled from the water supply nozzle 15 onto the endothermic material 11 and falling falls along the upper and lower surfaces of the porous plate 10. Then, a water film is formed and flows down, and water droplets do not drop from the hole 10b into the combustion chamber 4, so that the burner 5 in the combustion chamber 4 is not misfired or the combustion state is not deteriorated. Further, the water flowing down through the heat absorbing material 11 forms a water film along the upper and lower surfaces of the perforated plate 10 and the entire wall surface of the combustion chamber 4, so that the water overheats the wall surfaces of the perforated plate 10 and the heater body 2. In addition, the contact area between the combustion gas and water increases, which makes it possible to further improve the thermal efficiency.

FIG. 3 is a flow chart for explaining the operation. When the process moves from step n1 to step n2 and the starting step is entered, the electromagnetic valve 45 is closed at step n3, and the discharge of the hot water stored in the hot water storage unit 3 is stopped. Further, the pilot burner 24 is ignited and the pump 32 is started. At step n4, the centrifugal blower 6 is started.

In step n5, the water temperature T1 in the vicinity of the intake port 46 is detected by the temperature detecting element 47, and in step n6 it is determined whether or not this water temperature T1 is lower than a predetermined desired temperature T0. Then, the electric flow rate control valve 14 is narrowed down, the amount of water supplied to the water supply nozzle 15 is reduced, and the flow proceeds to step n9. Otherwise, the flow moves to step n8 and the electric flow rate control valve 14 becomes the flow rate corresponding to the set temperature. Stop and move to step n9. The temperature T0 is set to 60 ° C., for example. In step n9, the solenoid valve 17 is opened and the water supply nozzle
From 15 to the heat sink 11, step n7 or step n8
At the adjusted flow rate, watering is started at step n1
At time 0, the fuel cutoff valve 18 is opened at step n11 and the burner body 23 is opened after a delay of a time W1, which is substantially equal to the time required for the sprinkled water to reach the combustion chamber 4, for example, 2-3 seconds.
Ignites.

As described above, the step n7 or the step n8 is based on the difference between the temperature T1 detected by the temperature detecting element 47 and the predetermined desired temperature T0.
Since the temperature of hot water flowing into the hot water storage unit 3 is controlled by controlling 14, the temperature T1 has dropped to 20 ° C., for example, when the operation is restarted in the morning, and thus the temperature difference is large. Sometimes high-temperature hot water is generated, and when the temperature difference is small, hot water having a temperature close to the desired temperature T0 is generated. Therefore, hot water having a desired constant temperature T0 can always be stored in the hot water storage unit 3.

Also, after watering is started at step n9, the burner body 23 is ignited at step n11 by the time W1 being delayed at step n10, so that the burner body 23 is ignited before the water penetrates the heat absorbing material 11. Since this is prevented, hot hot water is prevented from flowing into the hot water storage unit 3. Since the burner 5 is burned after the water has penetrated into the heat absorbing material 11 and the water film has started to be formed on the wall surface of the combustion chamber 4, deterioration of these portions can be suppressed.

In step n12, it is judged whether or not the water level of the hot water storage unit 3 is equal to or higher than the first water level H which can be detected by the water level detection element 37, and if so, the process moves to step n13 and the solenoid valve 45 is opened for the time W4. Even if the valve state is set and the newly generated hot water flows into the hot water storage unit 3, the water level in the hot water storage unit 3 has an appropriate amount.
The water having the lowered temperature is discharged to the drain pipe 43 so as to be between the water level H and the second water level M. This time W4 is determined according to the temperature difference between the predetermined desired temperature T0 and the actual temperature T1 of the hot water. Therefore, the greater the temperature difference, the longer the time W4
Is long, and even if water is sprinkled until the temperature T1 of the hot water in the hot water storage unit 3 reaches the temperature T0, there is no risk of the hot water storage unit 3 overflowing. The relationship between the temperature difference and the time W4 is shown in FIG.

In step n14, it is judged whether or not the stop switch has been operated, and if not, it moves to step n15 to judge whether or not the water level of the hot water storage unit 3 has recovered to the first water level H, and if not so, it returns to step n5. When the water level is restored to the first water level H, move to step n16,
The electromagnetic valve 17 is closed to stop the water sprinkling from the water supply nozzle 15, and the time W2 which is substantially the same as the time required for the water sprinkled in the step n17 to flow down from the heat absorbing material 11, for example, 2 to
After a delay of 3 seconds, the fuel shutoff valve 18 is closed and the burner 23 is extinguished at step n18. In this way, when the generated warm water is used and it is determined in step n19 that the water level has dropped to the second water level M, the process returns to step n5. By repeating the operations of steps n5 to n19, the warm water at the constant temperature T0 is stored up to the first water level H.

Stop watering at step n16, and wait for W2 at step n17.
After the delay, by digesting the burner body 23 with step n18, the unheated low-temperature water flows into the hot water storage unit 3, and the temperature of the hot water in the hot water storage unit 3 decreases. Is prevented. Therefore, the temperature of the hot water stored in the hot water storage section 3 can be maintained at a predetermined desired constant temperature T0.

When the water level in the hot water storage unit 3 is less than the first water level H in step n12, the process moves to step n20, and the water level is the lower limit value L.
If it is not, that is, if the water level is not less than the lower limit value L and less than the first water level H, the process proceeds to step n14, where the water level is the first level as described above.
Warm water is generated until the water level H is reached. At step n20, when the water level is below the lower limit value L, that is,
Even if the hot water continues to be used beyond the second water level M, when the amount of hot water flowing into the hot water storage unit 3 cannot catch up with the amount of hot water supply due to an abnormality in the flow control mechanism 33 or the like, in order to maintain the water seal, step n21 Then, the solenoid valve 17 and the fuel cutoff valve 18 are closed to stop the water spray and the combustion of the burner 5, and the pump 32
Then, the centrifugal blower 6 is stopped and an alarm is issued in step n22.

When the stop switch is operated in step n14, the process proceeds to step n23, in which the solenoid valve 17 is closed and the water supply nozzle 1
Stop watering from 5, and open the solenoid valve 45,
The discharge of hot water in the hot water storage unit 3 is started. After a predetermined time W3 has been delayed at step n24, the fuel cutoff valve 18 is closed at step n25 to burn out the burner body 23 and the pilot burner 24, and the pump 32 and the centrifugal blower 6 are stopped. , Step n26 ends all operations.

Thus, after stopping watering at step n23 and delaying by time W3 at step n24, by digesting the burner body 23, the heat absorbing material 11 and the perforated plate 10 are hot-air dried in a so-called empty state. It is possible to obtain a sterilizing effect of suppressing the growth of various bacteria and algae, and to supply sanitary hot water. In this case, the time W3 is the heat absorbing material 11 and the perforated plate 10.
Is selected to be 200 to 300 ° C. or higher, for example, for about 10 seconds. Instead of heating the burner body 23 for the time W3 to dry the heat absorbing material 11 and the perforated plate 10, only the pilot fire by the pilot burner 24 may be ignited for a relatively long time. In addition, when the operation is not performed for a relatively long period of time, it is preferable to completely blow the can water in the hot water storage unit 3.

Further, since the solenoid valve 45 is opened and the hot water is started to be discharged, the operation is stopped. Therefore, when the operation is restarted, the water level of the hot water storage unit 3 is lowered to the height l4. Is lower than the second water level M, sprinkling and combustion of the burner are started, hot water having a relatively high temperature generated is replenished, and hot water having a predetermined desired temperature T0 is stored up to the first water level H. To be done. Therefore, even at the start of operation,
Hot water at the desired temperature T0 can be used.

Effects As described above, according to the present invention, when the operation is not performed for a relatively long time, the hot air that stops the water sprinkling, maintains the combustion state in the combustion chamber for a predetermined short time, and evaporates the water droplets retained in the endothermic material. Since the drying is performed, a sterilizing effect can be obtained and sanitary hot water can be supplied.

[Brief description of drawings]

FIG. 1 is a sectional view of a direct contact type hot water heater 1 according to an embodiment of the present invention, FIG. 2 is a sectional view around a flow rate control mechanism 33, FIG. 3 is a flow chart for explaining the operation, and FIG. Is the temperature T1 of the hot water stored in the hot water storage unit 3 and the predetermined temperature T0
6 is a graph showing a valve opening time W4 of a solenoid valve 45 with respect to a difference between 1 ... warm water heater, 2 ... heater body, 3 ... hot water storage part,
4 ... Combustion chamber, 5 ... Burner, 6 ... Centrifugal blower, 9 ...
Heat absorption chamber, 10 Perforated plate, 11 Heat absorbing material, 12 Water sprinkling chamber, 14 Electric flow control valve, 15 Water supply nozzle, 17
Solenoid valve, 18 ... Fuel cutoff valve, 33 ... Flow control mechanism, 34 ...
… Hot water pipe, 37-39 …… Water level detector, 47 …… Temperature detector

Front page continuation (72) Toshimichi Ohara, 5-1, Hirano-cho, Higashi-ku, Osaka, Osaka Prefecture (72) In Osaka Gas Co., Ltd. (72) Kunihiro Kobayashi 8-63, Miwa, Nagano-shi, Nagano (72) Inventor Kazuo Kobayashi 832-4 Shimoice, Inari-cho, Nagano-shi, Nagano Prefecture (72) Inventor Shoji Otsuka 2358-1 Okura, Toyono-cho, Kamimizunai-gun Nagano (72) Inventor Juno Hara 3321 Iiyama, Iiyama-shi, Nagano Prefecture (56) ) References Actual development Sho 49-25052 (JP, U)

Claims (1)

[Claims] 1. A combustion chamber provided with a burner is formed in a cylindrical body, and an endothermic chamber filled with an endothermic material is formed above the combustion chamber, and water is sprinkled from above the endothermic chamber to burn with the water. A direct contact hot water heater that directly contacts the combustion gas from the chamber, characterized by maintaining the combustion state in the combustion chamber for a short period of time after stopping sprinkling when the operation is stopped.