JPH0223926Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a water supply control device for a vacuum steam type hot water heater equipped with a heat exchanger for heating water for hot water supply or space heating.

Vacuum steam type hot water heaters are sealed internally, and the generated steam gives heat to the heat exchanger installed at the top of the heater, which supplies water for hot water supply and space heating, and converts it into condensate. It is repeatedly used as canned water after falling down, and it is relatively easy to handle because it does not require a constant water supply like other boilers, and in recent years it has been used in buildings, dormitories, and even homes. It has become like that. However, non-condensable gas gradually accumulates inside the vacuum steam type hot water heater and obstructs heat transfer in the heat exchanger, so it is necessary to bleed the gas from time to time. In this case, a large amount of steam is also extracted along with the non-condensable gas, and the water in the can gradually decreases, so it is necessary to occasionally supply water to keep the water level at an appropriate level. Conventionally,
An example of a vacuum steam type hot water heater equipped with a water supply control device that has been used for such water supply purposes is shown in FIG. 1, and its construction is as follows. 1 is a vacuum steam type hot water heater body into which canned water W is injected. Reference numeral 2 denotes a heat exchanger provided inside and above the hot water heater main body 1, into which water for hot water supply and space heating is supplied. Reference numeral 3 denotes a water level detection cylinder, which is communicated with the side of the hot water heater main body 1 through upper and lower communication pipes 3a and 3b. 4 is a burner, 5 is a water supply electromagnetic valve, 6 is a starting switch, 7 is a self-holding relay, 7a is a contact point of the self-holding relay, 8 is a power switch, 9 is a non-condensable gas vent valve, and 10 is a vacuum pump. The water level detection tube 3 is provided with an upper limit water level electrode E1 at the highest position as indicated by the lower end of each electrode, a lower limit water level electrode E2 at a lower position, and a lower electrode E3 at an even lower position. E
1 lower end E1a and lower end E2a of lower limit water level electrode E2
The position of the canned water W is adjusted to limit the height of the water surface Wa of the canned water W, that is, the water level, to an appropriate range. Reference numeral 11 is a floatless switch having a first contact U1 and a second contact U2. First contact U1
is the upper limit water level electrode E1 and/or the lower limit water level electrode E
2 and the lower electrode E3 are provided in the first circuit 1 formed through water, and as described later, the upper limit is set only after the water level reaches the upper limit water level electrode E1 and until it falls below the lower limit water level electrode E2. It operates to bring the water level electrode E1 and lower limit water level electrode E2 into electrical continuity. On the other hand, the second contact U2 is always enabled to be energized by turning on the power switch 8.
The water supply solenoid valve 5 is provided in the second circuit m that is opened and closed only by the contact U2, and is operated OFF and ON in conjunction with the ON and OFF operation of the first contact U1. It is operated in conjunction with contact U2. In Fig. 1, the water supply solenoid valve 5 is provided directly in the second circuit m, but a separate circuit for operating the water supply solenoid valve 5 is provided, and a relay switch for opening and closing this separate circuit is operated by the second circuit m. It may be arranged as follows.

In this way, the water supply control device conventionally used has an upper limit water level, a lower limit water level, and each lower electrode E1,
It is composed of E2, E3, a floatless switch 11, a first circuit 1, a second circuit m, and a water supply solenoid valve 5, and its operation is as follows. When the hot water heater is in operation and water is not supplied to the hot water heater main body 1, the second contact U2 that operates the water supply solenoid valve 5 is in the OFF state as shown in FIG. U1 is ON
In this state, the lower electrode E3 is energized via the canned water W to the lower limit water level electrode E2, and the first circuit 1 is closed, so that the floatless switch 11 is energized, and the first circuit 1 is closed. Contact U1 is
Connect the ON state. As soon as the water level gradually falls and the water surface Wa separates downward from the lower end E2a of the lower limit water level electrode E2, both the upper limit water level electrode E1 and the lower limit water level electrode E2 are separated from the water surface Wa, so the first circuit l opens. Then, the excitation of the floatless switch 11 disappears, and the first
The contact U1 is turned OFF, and in conjunction with this, the second contact U2 is turned ON, the second circuit m is closed, the water supply solenoid valve 5 is operated, and water supply to the hot water heater main body 1 is started. The water level rises due to water supply, and the canned water W soaks the lower end E2a of the lower limit water level electrode E2, but since the first contact U1 is in the OFF state, the first
Since the circuit 1 remains open and the floatless switch 11 is not energized, both the first contact U1 and the second contact U2 are not activated, so that water supply continues. As soon as the water level rises further and the canned water W immerses the lower end E1a of the upper limit water level electrode E1, the lower electrode E3 connects to the upper limit water level electrode E1 via the canned water W.
By configuring the circuit 1 in a closed state, the floatless switch 11 is energized, and the first contact U1 and the second contact U2 operate in conjunction with each other, and are in the ON and OFF states, respectively, as shown by the solid lines in Figure 1. , the second circuit m is opened and the water supply is stopped. Then, as the non-condensable gas is extracted, steam is also discharged, and the water level begins to gradually fall again. In this manner, the first contact point U1 establishes conduction between these electrodes E1 and E2 only after the water level reaches the upper limit water level electrode E1 until it falls below the lower limit water level electrode E2. In this way, the water level is always maintained at an appropriate level by moving up and down between the upper limit water level electrode E1 and the lower limit water level electrode E2.

However, such conventional water supply control devices have the following drawbacks. If the vacuum steam hot water heater as described above is not used at night, the power switch 8 is turned off and the operation is temporarily stopped. (Such operation stoppages are routinely carried out in buildings, homes, etc. where vacuum steam hot water heaters are preferred) and power terminals a and b of the excitation part of the floatless switch 11 are also not energized.
The first contact U1 remains ON until the power switch 8 is turned off.
Even in this state, the floatless switch 11 is de-energized, the first contact U1 is turned OFF, and the second
Contact U2 is in the ON state. Therefore, when the power switch 8 is turned on to resume operation next time, the first contact U1 is always OFF and the second contact U1 is ON, so the water supply solenoid valve 5 is activated as explained above. Water is supplied until the water level reaches the lower end E1a of the upper limit water level electrode E1. However, since it is normal for the entire canned water W to have cooled down while the operation is not in operation, the start switch 6 is pressed to activate the self-holding relay 7 and its contact 7a is turned ON to turn on the burner 4.
Even if the water level starts to heat the canned water W, the temperature does not rise suddenly and the water level rises, causing the upper limit water level electrode E1 to rise.
The lower end E1a of the container is filled with low-temperature canned water. In this way, as the water temperature rises in a state filled with low-temperature water to the upper limit water level, the volume of the canned water W thermally expands, and the water surface Wa of the canned water W rises from the lower end E1a of the upper limit water level electrode E1 by the amount of thermal expansion. do. When the temperature rises from a predetermined temperature, for example, from 30°C to 85°C, the height of the water surface Wa rises is 40 to 50 mm with a heater with an output of about 1 million kcal/hour. This rise in water surface Wa causes the lower part of heat exchanger 2 to be submerged in canned water W, and the height of the steam chamber (space above water surface Wa) decreases from the design value by the rise in water surface Wa. The heat transfer performance of the heat exchanger 2 deteriorates because priming (a phenomenon in which generated steam contains many water droplets) is likely to occur. However, in this type of hot water heater, which is characterized by easy handling that allows one or two switches to be operated without much attention, when restarting operation, for example, burner 4 is first activated and its temperature increases. It is undesirable to operate the water supply solenoid valve 5 without wasting time after confirming that the water has been completely drained and then operate the switch to activate the water supply solenoid valve 5. This is a major drawback of the above-mentioned conventional water supply control devices.

The inventor of the present invention has developed the present invention as a result of studies aimed at providing a water supply control device that does not have such drawbacks.

That is, the present invention includes an upper limit water level electrode, a lower limit water level electrode, and a lower electrode located further below the lower limit water level electrode and forming a circuit with the upper limit water level electrode and/or the lower limit water level electrode via water. a first circuit having a first contact that connects the upper limit water level electrode and the lower limit water level electrode only until the water level falls below the lower limit water level electrode after reaching the upper limit water level electrode;
When the first contact of the circuit is not connected to the upper limit water level electrode and the lower limit water level electrode,
A second circuit having a second contact that is ON and OFF when conducting, and the ON/OFF of the second contact.
In an electrode-type water supply control device for a vacuum steam hot water heater, which is equipped with a water supply solenoid valve that is operated in conjunction with the water supply solenoid valve, and whose first contact is activated when the power switch is turned on,
The present invention relates to a water supply control device for a vacuum steam hot water heater, characterized in that a third circuit having a third contact that turns off is connected to an upper limit water level electrode and a lower limit water level electrode.

The present invention will be explained in detail below with reference to FIG. 2, which shows one embodiment of the apparatus of the present invention.

In the figure, X is the third contact point and is the upper limit water level electrode E1
It is provided in the third circuit n that connects the lower limit water level electrode E2 and is turned off under specific conditions. Other numbers and symbols are the same as in FIG. 1.

The specific conditions under which the third contact X turns OFF can be divided into two. The first specific condition is the power switch 8
In other words, it is a state in which the power switch 8 changes from an OFF state to an ON state. In other words, the third contact in this case is turned off after the power switch 8 is turned on from off. A specific example of the third contact X that operates under the first specific condition is the b contact of the self-holding relay 7 of the starting switch 6 (when the self-holding relay 7 of the starting switch 6 is not operating). is in the ON state, and when the start switch 6 is turned on, the self-holding relay 7 is activated and turned OFF), or the start switch 6 is mechanically interlocked with the starting switch 6 that does not have a self-holding relay 7, and the start switch 6 is turned ON. ，
Contacts that turn OFF and ON in response to OFF (hereinafter referred to as interlocking contacts), and also the ON of the start switch 6.
Examples include contacts that turn from ON to OFF after a predetermined period of time due to the action of a timer or the like after being operated (hereinafter referred to as time difference contacts). Since these switches are operated after the starting switch 6, which is the basis of their operation, is turned on by the power switch 8, they will operate from ON to OFF under the first specific condition.

Another second specific condition is that the hot water heater body 1
In other words, the characteristic value indicating the state inside the hot water heater main body 1, which is in a state different from the steady operating state due to the suspension of operation, is closer to the steady operating state than the constant value. Under this second specific condition, the third contact point
It operates in the OFF position. Temperature or pressure is used as such a specific value. A specific example of the third contact X that operates under the second specific condition is a contact that is operated by a temperature switch,
It is turned ON when the temperature inside the hot water heater body 1 is lower than a certain temperature set lower than the temperature in a steady operating state, and turns OFF when the temperature rises and becomes higher than the certain temperature. Temperature switch contacts are shown. As a contact operated by such a temperature switch, the contact of the temperature switch may be used as it is as the third contact X, but it may be a contact that opens and closes under the control of the contact of such a temperature switch. . Another specific example is a contact operated by a pressure switch, which is turned ON when the pressure inside the hot water heater body 1 is lower than a constant pressure that is set to be a predetermined pressure lower than the pressure in a steady operating state. A pressure switch is shown which turns OFF when the pressure increases and becomes higher than the constant pressure.
As a contact operated by such a pressure switch, the contact of the pressure switch may be used as it is as the third contact X, but it may be a contact that opens and closes under the control of the contact of the pressure switch. The effect of the present invention can be demonstrated even when restarting operation after a short stoppage, as the constant temperature and constant pressure at which the temperature switch and pressure switch operate are close to those in steady operating conditions. It is determined as appropriate depending on the degree of necessity for the effects of the present invention, such as the structure of the hot water heater. The device of the present invention constructed as described above operates as follows. When the hot water heater is stopped from normal operation by turning off the power switch 8, the water level is between the lower end E1a of the upper limit water level electrode E1 and the lower end E2a of the lower limit water level electrode E2, as shown in FIG. The first contact U1 is OFF and the second contact U2 is ON. When the third contact X is the B contact, joint contact, or time difference contact of the self-holding relay 7 of the start switch 6, it becomes ON at the same time as the power switch 8 is turned off, and the third contact X is activated by the temperature switch. If the switch is operated by a contact or a pressure switch, the third contact
The state will be as follows. Therefore, the lower limit water level electrode E2 is the canned water W.
The first circuit 1, which is composed of the lower electrode E3 and the first contact U1, connects the upper limit water level electrode E1 and the lower limit water level electrode E2 even though the first contact U1 is in the OFF state. The third contact X of the third circuit n
Since it is ON, it is in the same state as if it were closed. When the power switch 8 is turned on to restart the operation of the hot water heater in such a dormant state, the power terminals a and b of the floatless switch 11 are also energized, so the floatless switch 11 becomes energized. Moreover, as described above, since the first circuit l is in the same state as closed, the first contact U1 is immediately activated and turned ON, and therefore the second contact U2 is activated OFF and the water supply solenoid valve 5 is not energized. From this point on, water is not supplied to the hot water heater main body 1. After that, the start switch 6 is turned on and heating by the burner 4 is started. If the third contact X is the B contact, joint contact, or time difference contact of the self-holding relay 7 of the start switch 6, the third contact X turns OFF at the same time or after a predetermined time delay when the start switch 6 is turned on. Operate. If the third contact X is a contact operated by a temperature switch or a pressure switch, the third contact 3 Contact X operates OFF. In other words, regardless of whether the third contact X is any of the above, it will turn OFF after the start switch 6 is turned on.
When the power switch 8 is turned on, the first contact U1 is closed.
The second contact U2 is turned ON and the second contact U2 is turned OFF, and then the third contact X is turned OFF. However, once the third contact When the lower limit water level electrode E2 leaves the lower end E2a, the first contact U1 is turned OFF and the second contact U2 is turned ON, and water supply is started.
The operating state is exactly the same as that of the conventional hot water heater described above. In this way, even if the hot water heater is restarted from a suspended state, it will not be filled with low-temperature water to the upper limit water level, and therefore the function of the heat exchanger 2 will not be degraded. Thus, the device of the present invention can be started without the disadvantage of filling up to the upper limit water level with low-temperature water when restarting the operation of the hot water heater by the simple operation of turning on the power switch 8 and then turning on the start switch 6 without requiring special attention. This improvement improves the functionality of vacuum steam hot water heaters, and is valuable in popularizing the functionality of vacuum steam hot water heaters.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a conventional water supply control device, Figure 2
The figure is an explanatory diagram of one embodiment of the device of the present invention. 1...Hot water heater main body, 2...Heat exchanger, 3
...Water level detection tube, 3a...Upper communication pipe, 3b...
Lower communication pipe, 4...Burner, 5...Water supply solenoid valve, 6...Start switch, 7...Self-holding relay, 7a...Contact of self-holding relay, 8...Power switch, 9...Non-condensing Gas vent valve, 10...Vacuum pump, 11...Switch without float, E1
... Upper limit water level electrode, E1a ... Lower end, E2 ... Lower limit water level electrode, E2a ... Lower end, E3 ... Lower electrode, U1 ... First contact, U2 ... Second contact, X ...
...Third contact, W...canned water, Wa...water surface, l...
First circuit, m...second circuit, n...third circuit.

Claims (1)

[Claims for Utility Model Registration] 1. An upper limit water level electrode, a lower limit water level electrode, and a lower electrode located further below the lower limit water level electrode and forming a circuit with the upper limit water level electrode and/or the lower limit water level electrode via water. a first circuit having a first contact point that connects the upper limit water level electrode and the lower limit water level electrode only until the water level falls below the lower limit water level electrode after the water level reaches the upper limit water level electrode; a second circuit having a second contact that operates in conjunction with the contact and is turned ON when the first contact is not conducting the upper limit water level electrode and the lower limit water level electrode and turned OFF when the upper limit water level electrode and the lower limit water level electrode are conducting;
It is equipped with a water supply solenoid valve that is operated in conjunction with ON/OFF, and the first contact is the power switch.
In an electrode type water supply control device for a vacuum steam hot water heater that is activated when turned ON, a third circuit having a third contact that changes from ON to OFF under specific conditions is connected to an upper limit water level electrode and a lower limit water level electrode. A water supply control device for a vacuum steam hot water heater, characterized in that: 2. The vacuum steam type according to claim 1 of the utility model registration claim, wherein the third contact that changes from ON to OFF under specific conditions is a contact that changes from ON to OFF after the power switch changes from OFF to ON. Water supply control device for hot water heaters. 3 The third contact, which changes from ON to OFF under specific conditions, changes from ON to OFF when the characteristic value indicating the state inside the hot water heater approaches the operating state than a certain value.
The first scope of claims for utility model registration, which is the point of contact
A water supply control device for a vacuum steam hot water heater as described in 2. 4 The characteristic value is the temperature inside the hot water heater and the third
The water supply control device for a vacuum steam type hot water heater according to claim 3, wherein the contact point is a contact point operated by a temperature switch. 5 The characteristic value is the pressure inside the hot water heater and the third
The water supply control device for a vacuum steam type hot water heater according to claim 3, wherein the contact point is a contact point operated by a pressure switch.