JPS6055728B2 - Pump control device for hot water system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pump control device for a hot water supply system.

As shown in FIG. 2, a pump 4 is provided in the hot water supply pipe 37,
If a second floor hot water supply system is adopted in which the pump 4 is controlled by a pump control device 44 that is controlled by a flow rate switch 36 that opens and closes depending on the amount of hot water flowing through the hot water supply piping 37, the second floor where hot water supply pressure is required is installed. Even when hot water is being supplied, a sufficient flow rate of hot water can be ensured and maintained.

In FIG. 2, 38 is a water heater, 39 and 39 are safety valves, 40 is a pressure reducing valve, 41 is a water supply valve, 42 is a water supply pipe, and 43 is a hot water tap. Further, as shown in FIG. 3, the return pipe 45 is connected to the hot water supply pipe 37, and the return pipe 45 is
If a hot water supply system is adopted in which a pump 4 is installed inside the return pipe 45 and the pump 4 is controlled by a pump control device 44 controlled by a thermistor 14 whose resistance value changes depending on the temperature of hot water in the return pipe 45, the hot water supply pipe 37 A so-called freeze prevention/immediate hot water supply system can be obtained in which freezing of the return pipe 5 and pipe 45 can be prevented, and hot water can be used immediately when the hot water tap 43 is opened.

In addition, in FIG. 3, 46 is a check valve. Furthermore, a return pipe 45 is connected to the hot water supply pipe 37, and a pump 4 is provided in the hot water supply pipe 37 or the return pipe 45, and the pump 4 is controlled by a pump control device 44 controlled by the flow rate switch 36 and the thermistor 14. If a hot water supply system is adopted, sufficient hot water flow rate can be obtained even when hot water is supplied on the second floor, which requires hot water pressure, and the thermistor 14 automatically controls the pump 4 to prevent the hot water temperature from falling below a predetermined temperature. By being operated, the hot water supply pipe 37 and the return pipe 4
It is possible to obtain a hot water supply system which can prevent water from freezing and can use immediate hot water by circulating hot water when the hot water tap 43 is opened. The present invention provides a pump control device for a hot water supply system that allows a single pump control device to control the pumps employed in the various hot water supply systems described above.
An embodiment of the present invention will be described below with reference to FIG.

That is, in the figure, 1 is an AC power source, 4 is a pump connected to this AC power source 1 via a current fuse 2, and a contact 7 that is opened and closed by an energizing coil 32 of a relay, which will be described later.
It is installed in hot water supply piping or return piping in floor hot water supply systems, immediate hot water supply systems, hot water/freezing prevention hot water systems, etc.

In addition, a fixed resistor 6 and a capacitor 5 are installed to protect the contact 7.
is connected in parallel to the contact 7.
3 is a varistor for surge absorption, 8 is 3 connected to power supply 1
Step-down transformers 9 and 37 are diodes connected to the secondary side of step-down transformer 8, and together with capacitor 12 constitute a rectifier circuit.

Reference numeral 10 denotes a change-over switch for activating or deactivating a thermistor 14, which will be described later.

13 is a capacitor, 11 is a fixed resistor, and 14 is a thermistor, which are installed near the hot water supply pipe or return pipe as piping in the hot water supply system, and whose resistance value changes depending on the temperature of hot water in the hot water supply pipe or return pipe. .

16 is a fixed resistor, 17 is a variable resistor, 18 is a capacitor,
415 is a diode for dissipating the charge of the capacitor 18.

19, 20, 23 are fixed resistors, 25 is a comparator,
21 is a variable resistor, 22 is a fixed resistor, and 26 is a diode, which together with the variable resistor 21 and fixed resistor 22 constitute a differential setting circuit, and the output of the comparator 25 is
When the temperature becomes high, the purpose is to prevent chattering by adjusting the difference in LO, and by adjusting the variable resistor 721, the opening and closing of the transistor 31, which will be described later, is controlled.For example, when the thermistor 14 temperature is 70°C, it is set to 0FF. When the temperature of the thermistor 14 is 50°C, it is set to 0N, and when the temperature of the thermistor 14 is 50°C, it is set to 0FF, and when the temperature of the thermistor 14 is 40°C, it is turned on.

24 is a capacitor for noise prevention, 27 is a capacitor 29
, 30 is a fixed resistor, 31 is a transistor as a switch means whose conduction is controlled by the thermistor 14, and 36 is a flow rate switch connected in parallel to the transistor 31, which is connected to the hot water supply pipe 37 or the return pipe 45 in the hot water supply system. It is installed in the hot water supply pipe or return pipe and automatically opens and closes depending on the amount of hot water flowing through the hot water supply pipe or return pipe.

Reference numeral 32 denotes a relay energizing coil for controlling the pump 4, which is connected to a rectifier circuit including the diodes 7, 37, etc., through a parallel circuit of a transistor 31 and a flow rate switch 36.

Also, 34 is a fixed resistor, 35 is a capacitor, and fixed resistor 3
4 and protects the flow rate switch 36 when it is opened or closed. 33
is a diode, which is used to release back electromotive force when the energizing coil 32 of the relay is opened and closed.

The pump control device according to the present invention is configured as described above, and its operation will be explained next.

That is, if the selector switch 10 is now set to 0FF (open),
Since the thermistor 1, comparator 25, etc. do not operate, and the transistor 31 becomes non-conductive, the AC power supply 1 is connected to a step-down transformer 8, a rectifier circuit consisting of diodes 9, 37, and a capacitor 12, a transistor 31, and a flow rate switch 36.
energizing coil 3 of the relay connected through a parallel circuit with
2 will be controlled only by the flow rate switch 36. At this time, if the flow rate switch 36 is set to turn on when hot water flows at a predetermined flow rate (for example, 3e'Min) or more, when the flow rate switch 36 turns 0N, the energizing coil 32 of the relay is energized and connected. 7 becomes ON and the pump 4 can be driven. Such pump control can be used, for example, to control the f-pump employed in the second floor hot water supply system as shown in FIG. 2 described above. On the other hand, if the selector switch 10 is set to 0N (closed), the relay 3
2 is controlled by both the flow rate switch 36 and the transistor 31.

At this time, the flow rate switch 36 is set so that the hot water reaches a predetermined flow rate (for example, 3e
If the flow is set to 0N when the flow exceeds 1 min), if the flow rate switch 36 is set to 0N, the contact 7 of the relay's energizing coil 32 will turn 0N and drive the pump 4, and the thermistor 14 will turn 0N. When the temperature falls below a predetermined temperature, the transistor 31 becomes conductive, the energizing coil 32 of the relay is energized, the contacts 7 of the relay are turned ON, and the pump 4 can be driven. This type of pump control allows instant hot water supply while supplying hot water to the second floor as described above.
Furthermore, it can be used to control pumps used in hot water supply systems that can also prevent freezing.

Note that the transistor 31 is controlled as follows.
That is, a fixed resistor 2 is connected to the (+) terminal of the comparator 25.
A comparison reference potential is input through 0 and 23, and the thermistor 14, fixed resistor 16, and variable resistor 17 are input to the (-) terminal.
The voltage divided by is input, but now thermistor 1
4 is below a predetermined temperature, the resistance value of the thermistor 14 becomes large, and the (-) terminal of the comparator 25 becomes lower than the reference potential. Therefore, the output of the comparator 25 becomes ``H'' level and the fixed resistance 30 The transistor 31 becomes conductive due to the base potential of the thermistor 14, and the resistance value of the thermistor 14 becomes smaller than the predetermined temperature, so that the (-) terminal of the comparator 25 becomes higher than the reference potential, and therefore the output of the comparator 25 reaches the 66L level, and the transistor 31 is rendered non-conductive.Furthermore, the changeover switch 10 is turned ON (closed), and the flow rate switch 36 is deactivated (not shown in the circuit of the flow rate switch 36, but a If a changeover switch 100 is provided and the changeover switch is set to the OFF state), the energizing coil of the relay will be controlled only by the transistor 31.

That is, when the temperature of the thermistor 14 falls below a predetermined temperature, the transistor 31 becomes conductive as described above, and the relay's energizing coil 32 is energized to turn the contact 7 ON, allowing the pump 4 to be driven. Such pump control can be used to control pumps employed in any of the instant hot water supply system, the antifreeze hot water supply system, and the instant hot water supply/freeze prevention hot water supply system as shown in FIG. 3 described above.

As is clear from the above description, the present invention provides a hot water supply system in which a hot water supply pump is installed in a pipe through which hot water from a water heater passes, in which a relay contact is inserted into the power supply circuit of the pump, and the relay The energizing coil is connected to a power source through a parallel circuit consisting of a switch means that opens and closes depending on the temperature of the fluid flowing through the piping, and a flow rate switch that opens and closes according to the flow rate of the fluid flowing through the piping. In addition, a changeover switch is provided to arbitrarily disconnect the switch means from the power supply and make it inoperable independently of the opening and closing of the flow rate switch, and when the changeover switch is closed, the power supply to each of the switch means and the flow rate switch is switched off. By opening and closing the selector switch that connects the switch means to the power supply, the hot water pump can be easily switched to either a mode in which the water supply pump is controlled by only the flow rate switch or by both the flow rate switch and the switch means. Therefore, it can be easily applied to both a hot water supply system that provides instant hot water supply while supplying hot water on the second floor, and a hot water supply system that provides freezing prevention.

Further, the present invention provides a hot water supply system in which a hot water supply pump is provided in a pipe through which hot water from a water heater passes, as another configuration, in which a relay contact is inserted into the power supply circuit of the pump, and the relay is energized. The coil is connected to a power source through a parallel circuit consisting of a switch means that is opened and closed depending on the temperature of the fluid flowing through the piping, and a flow rate switch that is opened and closed according to the flow rate of the fluid flowing through the piping. , two change-over switches 10 and 100 are respectively provided to arbitrarily disconnect the switch means 31 and the flow rate switch 36 from the power supply 1 and render them inoperable independently of each other, and these two change-over switches 10 and 100 are Since the power supply 1 is connected to each of the switch means 31 and the flow rate switch 36 in a closed state, in addition to the above-mentioned effects, the switch means 31 and the flow rate switch 36 are connected to the power supply. By opening another changeover switch, the flow rate switch can be deactivated and the control of the hot water pump can be made dependent on the switch means which is opened and closed depending on the temperature of the fluid. The present invention can easily be adapted to a hot water supply system that can provide instant hot water supply and prevent freezing at the same time.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing a second floor hot water supply system to which the present invention is applied, and Fig. 3 is an instant hot water supply/freeze prevention hot water supply system to which the present invention is also applied. FIG.

Claims (1)

[Scope of Claims] 1. In a hot water system in which a pump 4 for hot water supply is provided in piping 37, 45 through which hot water from a water heater passes, a relay contact 7 is inserted into the power supply circuit of the pump, and the relay A switch means 31 which opens and closes the energizing coil 32 according to the temperature of the fluid flowing in the pipe, and a flow rate switch 3 which opens and closes according to the flow rate of the fluid flowing in the pipe.
a changeover switch 1 which is connected to the power supply 1 through a parallel circuit with the flow rate switch 36, and further disconnects the switch means 31 from the power supply 1 independently from the opening/closing of the flow rate switch 36 to render it inoperable;
0, and the switch means 31 is connected to the power supply 1 to the flow rate switch 36 when the changeover switch 18 is closed. 2. In a hot water supply system in which a pump 4 for hot water supply is provided in piping 37, 45 through which hot water from a water heater passes, a relay contact 7 is inserted into the power supply circuit of the pump, and the energizing coil 32 of the relay is inserted. , a switch means 31 that opens and closes depending on the temperature of the fluid flowing in the pipe, and a flow rate switch 3 that opens and closes according to the flow rate of the fluid flowing in the pipe.
6 are connected to the power source 1 through a parallel circuit, and furthermore, the switch means 31 and the flow rate switch 36 are arbitrarily disconnected from the power source 1 independently from each other to render them inoperable. A pump control device for a hot water supply system, in which a power source 1 is connected to the switch means 31 and the flow rate switch 36, respectively, with the two changeover switches 10 and 100 both closed.