JPS6032836Y2 - Circulation pump control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a circulation pump for forcedly supplying a heat medium within a heat source for cooling and/or heating operations.

Conventionally, this type of circulation pump has been controlled by using a manual switch, or by operating and stopping the pump in conjunction with a heat exchanger operation switch.

However, in the former method, even when the operation of the heat exchanger is stopped due to the operation of a thermostat or the like, the circulation pump continues to be operated, resulting in a waste of electrical energy.

Moreover, in the latter case, since a signal line is required between the heat exchanger and the circulation pump, there is an inconvenience that the construction is complicated and the installation cost is high.

The present invention was developed in view of the above points, and detects the temperature difference between the heat medium flowing out from the heat source and the heat medium flowing in.
By making the circulation pump operate when it receives at least one signal of the signal corresponding to this temperature difference and a separate discontinuous circulation pump operation signal, the circulation pump operates according to the operation of the heat exchanger. This made it possible.

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

1 is a commercial power supply, 2 is a hot water circulation pump that forcibly supplies hot water as a heat medium from a heat source to a heat exchange device (not shown) and returns it into the heat source after passing through the heat exchange device; 3 is a hot water circulation pump 2; Relay contacts connected in series, 4 a power transformer, 5 a thermistor for hot water temperature detection arranged on the heat medium outflow side of the heat source, and 6 hot water temperature detection arranged on the heat medium inflow side of the heat source. 7.8 is the thermistor output characteristic correction resistor, 9 is the voltage dividing resistor, 10.1
1 is a resistance for correcting thermistor output characteristics, 12 and 13 are input resistances, 14 is a thermistor for detecting hot water temperature, together with thermistors 5 and 6, detects the temperature difference between the heat medium inflow side and the outflow side of the heat source, and detects a predetermined temperature difference or more. 15 is a positive feedback resistor, 16.17 is a voltage dividing resistor, 18 is a comparator that operates as an unstable multivibrator, 19 is a timer time constant. 20 is a resistor for charging the capacitor 19, 21 is a diode, 22 is a resistor for discharging the capacitor 19 connected in series with the diode 21, and together with the capacitor 19, the charging resistor 20, and the comparator 18, controls the operation of the circulation pump. It acts as a means of transmitting signals discontinuously and periodically.

23 is a positive feedback resistor, 24 is an output terminal of the comparator 18, an output terminal of the comparator 14, a charging resistor 20, and a discharging resistor 22.
A relay coil that controls the opening and closing of the relay contact 3 connected to the contact point P of , and is connected to the output terminal of the comparator 14.18 to discontinuously control the operation control signal of the temperature difference detection means and the circulation pump. It functions as a control circuit that receives at least one operation control signal among the signals from the transmitting means and controls the operation of the circulation pump.

25 is a back electromotive voltage canceling diode connected in parallel to the relay coil 24, 26 is a rectifying diode, and 27 is a power supply smoothing capacitor.

In the circulation pump control device having such a configuration, when the heat exchange device is in operation, the hot water that is the heat medium radiates heat through the heat exchange device, so that the temperature detected by the thermistor 6 for hot water temperature detection is equal to the hot water temperature on the inflow side. The resistance is lower than that of the detection thermistor 5 and greater than the resistance of the hot water temperature detection thermistor 5.

At this time, since the non-inverting input of the comparator 14 is lower than the inverting input, the output of the comparator 14 is at a low level.

As a result, the relay coil 24 is in an excited state, so the relay contact 3 is in a closed state and the hot water circulation pump 2 is in an operating state.

On the other hand, when the heat exchange device stops, the heat radiation of the hot water through the heat exchange device is drastically reduced, so the temperature of the hot water flowing into the heat source is relatively high (and the difference between the temperature of the hot water flowing out from the heat source is less than a predetermined value). .

At this time, the resistance values of the thermistors 5 and 6 for hot water temperature detection are approximately the same, and due to the presence of the voltage dividing resistor 9, the non-inverting input of the comparator 14 is at a higher level than the inverting input, so the output of the comparator 14 is Becomes a high level.

As a result, the relay coil 24 is demagnetized, the relay contact 3 is opened, and the hot water circulation pump 2 is stopped.

Therefore, if the heat exchange device is in a stopped state, the hot water circulation pump 2 is controlled to be in a stopped state.

Even if the heat exchange device is switched from the stopped state to the operating state, the hot water circulation pump 2 will not become active as it is, but the comparator 18 is determined by the capacitor 19, the charging resistor 20, and the discharging resistor 22. Since it operates as an unstable multivibrator that generates periodic pulses, the comparator 18 periodically outputs high and low levels in response to these pulses, and the relay coil 24 is excited when the comparator 18 outputs a low level. An exciting current periodically flows through the relay coil 24, and the hot water circulation pump 2 is activated and stopped periodically by the periodic opening and closing operations of the relay contacts 3.

Specifically, charging of the timer time constant capacitor 19 to 19 starts via the charging resistor 20, and the capacitor 19 starts charging.
When the potential of becomes equal to or higher than the potential of the non-inverting input of the comparator 18,
The comparator 18 outputs a low level, and the relay coil 24
is excited, and discharge of the capacitor 19 begins via the discharge resistor 22.

When the potential of the capacitor 19 becomes lower than the potential of the non-inverting input due to this discharge, the comparator 18 outputs a high level, and the relay coil 24 is demagnetized while the charging resistor 2
Charging of the capacitor 19 is started via 0, and the above operation is repeated in the same manner.

Therefore, if the heat exchange device is in operation due to the periodic operation of the hot water circulation pump 2, a temperature difference is created between the heat medium flowing out from the heat source and the heat medium flowing in, and the hot water temperature detection thermistors 5 and 6 and the comparator 14, the relay coil 24 is maintained in an excited state, and the hot water circulation pump 2 continues to operate via the relay contact 3.

In this way, in this embodiment, when the heat exchange device is in an operating state, the hot water circulation pump 2 continues to operate, and when the heat exchange device is in a stopped state, the hot water circulation pump 2 only operates discontinuously. , the hot water circulation pump 2 can be operated efficiently, leading to labor savings.

Figure 2 shows activation/stopping of the heat exchange device B according to indoor temperature A.
It shows the temperature difference C between the temperature of the hot water flowing out from the heat source (boiler) and the temperature of the hot water returning to the heat source depending on the state, and the operating/stopping state of the hot water circulation pump 2 according to this temperature difference.

In the above embodiment, the temperature difference is detected by measuring the temperature of the hot water flowing out from the heat source and the temperature of the hot water flowing into the heat source. However, if the temperature of the hot water inside the heat source is known, It is only necessary to provide a thermistor for hot water temperature detection to measure the temperature of the hot water.

In addition, although hot water is used as the heat medium of the heat source and the heat exchange device is used for heat radiation, it is clear that the present invention can also be applied to a case where a low temperature material is used as the heat medium and the heat exchange device is used for heat absorption. Furthermore, it can be applied to any number of heat exchange devices.

Further, the means for transmitting the discontinuous circulation pump operation control signal is not limited to the embodiment.

As explained above, according to the present invention, the operation/stop status of the heat exchange device is determined based on the temperature difference between the heat medium flowing out from the heat source and the heat medium flowing in, and the operation of the circulation pump is controlled according to this determination. On the other hand, since discontinuous operation control signals are sent to the circulation pump, the circulation pump operates continuously when the heat exchanger is activated, but only occasionally when the heat exchanger is stopped. Therefore, labor-saving operation of the circulation pump can be achieved.

Moreover, since it is only necessary to arrange the signal line in the heat source section, the construction work is simple and has the advantage of being inexpensive.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a control device for a circulation pump that is an embodiment of the present invention, and Fig. 2 A, B, C, and D show the indoor temperature, heat exchange device, temperature difference, and operation of the hot water circulation pump by the same control device. A characteristic diagram is shown. 2...Hot water circulation pump, 3...Relay contact, 5.6...Hot water temperature detection thermistor,
14, 18... Comparator, 19... Capacitor for timer time constant, 20... Charging resistor,
22...Resistance for discharge.

Claims (1)

[Scope of utility model registration request] In a circulation pump that forcibly supplies a heat medium in a heat source to a heat exchange device, causes the heat medium to receive and receive heat through the heat exchange device, and returns the heat medium to the heat source, which flows out from the heat source. Temperature difference detection means for detecting a temperature difference between a heat medium and a heat medium flowing into the heat source and transmitting a circulation pump operation control signal when a predetermined temperature difference or more is detected; and discontinuously transmitting a circulation pump operation control signal. and a control circuit that receives at least one operation control signal from the signals from the two means and controls the operation of the circulation pump.