JPS6131791B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a boiler having an auxiliary tank for replenishment when the amount of heat medium in the can decreases, and particularly relates to the detection of the heat medium. The purpose of this system is to provide a circuit to improve the safety of the boiler and to facilitate the replenishment of heat medium.

In conventional hot water boilers of this kind, the method for detecting the heating medium was to provide a detector in either the can body or the auxiliary tank. In such a case, first of all, with the method of installing a detector in the can body, the heat medium will decrease, and if you forget to refill the auxiliary tank, the heat medium in the auxiliary tank will completely run out. However, the operation continues and will not stop unless the heat medium inside the can decreases. At that point, air is trapped in the heating circuit, making replenishment extremely difficult. Furthermore, the method of installing a detector in the auxiliary tank is extremely dangerous because if the detector malfunctions and the heat medium decreases, the tank will run dry. Furthermore, when the heating medium inside the can is suddenly reduced due to an accident such as damage to the can, there is also the problem that the heating becomes dry.

The present invention was made in order to solve these conventional problems, and the can body and the auxiliary tank are each provided with a detector, and the detector provided in the auxiliary tank prompts the replenishment of the heat medium. In the event of a failure of the detector or damage to the can, the detector installed inside the can will stop its operation. An embodiment thereof will be described below with reference to the drawings.

Figure 1 is the main body configuration diagram, 1 is the can body, 2 is the can body 1
An auxiliary tank for replenishing the heat medium inside when it decreases; 3 is a burner for warming the heat medium inside the can body 1; 4
is a circulation pump for conveying a heat medium to a hot water heat exchanger, etc., where A is a hot water pipe and B is a hot water return pipe.
Reference numeral 5 represents an electrode for detecting the heat medium within the can body 1, and reference numeral 6 represents an electrode for detecting the heat medium within the auxiliary tank 2.
With the above configuration, replenishment from the auxiliary tank 6 to the can body 1 is such that when the heat medium in the can body 1 decreases, a pressure difference occurs between the can body 1 and the auxiliary tank 2, and as a result, a pressure difference occurs inside the can body 1. It is sucked in and replenished. Figure 2 shows the load circuit, where 7 is the commercial power supply, 8 is the operation switch,
9 is a power transformer for the control circuit, 10 is a vaporization heater for burner 3, 11 to 15 are contacts for load control relays, 16 is a burner motor for burner 3, 17 is a pulse pump for supplying fuel to burner 3, 18 is the igniter for three burners. Fig. 3 shows a control circuit, 19 is a DC power supply for the control circuit, 20 is a vaporization heater control circuit, 21 is a hot water temperature thermo circuit, 22 is a pre-purge circuit for burner 3, 23 is an igniter drive circuit,
24 to 27 are relays controlled by the outputs of the respective circuits 20 to 23, 28 to 30 are resistors, 31 is a capacitor, 32 is an operational amplifier, 33 is a relay,
34 is a transistor, and the above-mentioned 28 to 34 form a circulation pump drive circuit. 35 is a combustion detection circuit for burner 3, 36 is a flame rod, 37 is a resistor, 38 is a capacitor, 39 to 42 are resistors, 43
is PUT, 44 is a transistor, and this 39
~44 and 5 form a heat medium detection circuit inside the can body 1. 45 to 48 are resistors, 49 is a PUT, 50 is a transistor, and 51 and 52 are diodes. 45 to 50 and 6 form a heat medium detection circuit in the auxiliary tank 2, and the outputs of the transistors 44 and 50 are
It is connected to the + input of the operational amplifier 32 in an AND configuration. Further, the output of the operational amplifier 32 and the input of the hot water temperature thermostat circuit 21 are connected via a diode 52,
When the circulation pump drive circuit is stopped, the hot water temperature thermocircuit 21 is turned off and the burner 3 is stopped.

In the above configuration, the operation is explained as follows.
First, with the can body 1 and auxiliary tank 2 sufficiently filled with heat medium, turn on the operation switch 8 shown in Fig. 2.
When turned on, power is supplied to the control circuit via the power transformer 9 and the DC power supply 19. As a result, the output of the vaporization heater control circuit 20 is first turned on,
The relay 24 is energized, the contact 11 in FIG. 2 is closed, and the vaporization heater 10 starts heating. At the same time, since the can 1 and the auxiliary tank 2 are sufficiently filled with the heating medium, a current flows between the electrodes 5 and 6 and d via the heating medium. As a result, PUTs 43 and 49 become conductive, and transistors 44 and 50 become OFF. That is, the capacitor 31 is charged through the resistor 28, and when the potential becomes higher than the potential determined by the resistors 29 and 30, the output of the operational amplifier 32 becomes 1 state, the transistor 34 is turned on, the relay 33 is energized, and the contact 12 is closed. Therefore, the circulation pump 4 is driven. Next, when the vaporization heater 10 continues to heat up and reaches a predetermined temperature, the stop signal to the hot water temperature thermocircuit 21 is released, and the subsequent combustion control circuit starts operating. First, when the output of the hot water temperature thermo circuit 21 is turned on, the relay 25 is energized, the contact 13 is closed, the burner motor 16 is driven, and then the pre-purge circuit 22
After a predetermined time has elapsed, the output turns ON and relay 26
is excited. At the same time, the igniter drive circuit 23 is turned on.
Then, the relay 27 is energized. As a result, contact 14
and 15 are closed, the pulse pump 17 and igniter 18 are driven, liquid fuel is supplied to the burner 3 section by the pulp pump 17, this is vaporized by the vaporization heater 10, and air from the burner motor 16 is mixed with this to ignite it. do. When ignited, the combustion detection circuit 35 deenergizes the OFF relay 27 of the igniter drive circuit 23 and opens the contact 15 via the flame rod 36, stopping the operation of the igniter 18 and transitioning to normal combustion. Next, when the heat medium in the can body 1 decreases in this state, a pressure difference occurs between the can body 1 and the auxiliary tank 2, as described above, and as a result, the heat medium in the auxiliary tank 2 decreases. However, as the replenishment progresses and the level of the heating medium falls below the installation level of electrode 6, the gap between electrode 6 and d becomes open, and the PUT
Gate 49 is set to high level, so PUT
The transistor 49 becomes non-conductive, and the transistor 50 becomes conductive because the base current is supplied through the resistors 46 and 47. When the transistor 50 is turned on, the charge in the capacitor 31 is discharged through the transistor 50. That is, the operational amplifier 32
The + input of is in a low state, and the output is also in a low state. As a result, the transistor 34 is turned OFF, the relay 33 is de-energized, the contact 12 is opened, and the circulation pump 4, burner motor 16, and pulse pump 17 are stopped and the fire is extinguished. At the same time, the control circuit side also connects the hot water temperature thermocircuit 2 via the diode 52.
1 is kept in the OFF state. If the auxiliary tank 2 is replenished here, it will automatically return and restart.

Next, the operation when the fuel detection circuit of the auxiliary tank 2 fails or the can body 1 is damaged will be explained. In this case, when the heat medium decreases below the installation level of the electrode 5 provided in the can body 1, the gap between the electrode 5 and d becomes open, so the PUT 43
Since the gate of the transistor 44 is set to a high level, it becomes non-conductive and the transistor 44 is turned on. This causes the + input of the operational amplifier 32 to go low and the output to
It becomes Low, the transistor 34 is turned off, the relay 33 is de-energized, the contact 12 is opened, and the circulation pump 4 and combustion are stopped. Here, when the power source of the fuel detection circuit is DC, there are problems such as formation of an oxide film due to polarization and melting of electrodes, so an AC power source is used.

As described above, according to the present invention, when the heat medium is decreasing, the operation is stopped before air is trapped in the heating pipes, prompting replenishment, and the replenishment operation is easy as only the auxiliary tank needs to be replenished. be. In addition, if the detection circuit on the auxiliary tank side malfunctions or the can body is damaged, the detection circuit on the can side will detect it, so there will be no dry firing, improving safety. It is something.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
3 and 3 are the same circuit diagrams. 1... Can body, 2... Auxiliary tank, 3... Burner, 4... Circulation pump, 5, 6... Electrode, 32...
...Operation amplifier.

Claims (1)

[Claims] 1 comprising a can body and an auxiliary tank that is connected to the upper part of the can body and replenishes the heating medium into the can body by a pressure difference with the can body when the heat medium in the can body decreases due to evaporation, etc.; The body and auxiliary tank are each equipped with a heat medium detection electrode and a detection circuit, and the output of each detection circuit is connected to the circulation pump drive circuit and the combustion ON-
Each boiler is connected to the input of the hot water temperature thermo circuit that performs OFF control.