JPH0527017B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a hot water temperature control device for a two-can, two-water type hot water heater.

Configuration of conventional example and its problems The hot water temperature control device of the conventional 2-can 2-water hot water heater uses a proportional control valve to control the fuel supply to the hot water burner on the hot water supply side, and proportionally controls the hot water temperature. The heating side uses multiple solenoid valves to maintain Hi-Lo.
-The mainstream method was to control the hot water temperature using OFF combustion. This is a so-called composite product that simply incorporates a water heater and a space heater into a single box, and is extremely expensive.

FIG. 1 shows a schematic diagram of the configuration of a conventional example.

1 is a heat exchanger for hot water supply, which has a water supply port 1a and a hot water supply port 1.
connected to b. 2 is a heating heat exchanger connected to a hot water return port 2a and a hot water outlet 2b.

The heating hot water passage A includes a pump 3, an expansion tank 4, and a bypass pipe 5.

An overflow pipe 6 is connected to the expansion tank 4.
An exhaust pipe 7 is connected to each of the heat exchangers 1 and 2.

The fuel passage branches off from the main solenoid valve 8, passes through the hot water supply solenoid valve 9 and the proportional control valve 10, passes through the hot water supply burner 11, through the heating Lo solenoid valve 12, the heating Hi solenoid valve 13, and the bypass passage 14, and then passes through the heating Lo solenoid valve 12, the heating Hi solenoid valve 13, and the bypass passage 14. It is connected to the burner 15 for use.

A hot water supply thermistor 16 is provided at the outlet of the hot water supply heat exchanger 1, and a comparator 17 compares the thermistor signal with a signal from the hot water temperature setting device 18, and the proportional control valve drive unit 19 is operated based on this comparison signal. , the proportional control valve 10 is operated to keep the hot water temperature constant, and the combustion amount of the hot water supply burner 11 is controlled.

On the other hand, a heating thermistor 20 is provided at the outlet of the heating heat exchanger 2, and the heating hot water temperature adjustment circuit 21 is operated by the thermistor signal, and the heating Lo solenoid valve 12 is operated.
The heating Hi electromagnetic valve 13 is operated to control the combustion amount of the heating burner 15 and to control the heating water temperature to be constant.

In order to control the temperature of each hot water, there are many fuel passage components, and a circuit for controlling the hot water temperature is required for each of hot water supply and heating, which increases the cost.

OBJECTS OF THE INVENTION In view of the above drawbacks, the present invention aims to provide a hot water temperature control device that reduces the number of parts and circuits, and stably controls the hot water temperature for hot water supply and heating.

Composition of the Invention In order to achieve this object, the hot water temperature control device for a hot water heater of the present invention connects a main solenoid valve and a proportional control valve in series, and branches each burner for hot water supply and heating to supply hot water. A solenoid valve for hot water supply and a solenoid valve for heating are installed, and the thermistor for hot water supply installed at the outlet of the heat exchanger for hot water supply and the thermistor for heating installed at the outlet of the heat exchanger for heating are passed through each comparator. Connected to a microcomputer having a proportional control calculation unit, hot water supply or heating, and a simultaneous mode switching processing unit, and operating a proportional control valve drive unit connected to the output side of the microcomputer to drive the proportional control valve, It is configured to control the combustion amount of each burner. By operating the proportional control valve with one proportional control valve drive unit, during hot water supply operation, the signal from the hot water supply thermistor is used to switch between the hot water supply/heating proportional control calculation unit of the microcomputer, hot water supply or heating, and simultaneous mode switching. The hot water supply mode output processed by the processing unit can drive the proportional control valve to stably control the hot water temperature, and during heating operation, the signal from the heating thermistor is used to perform proportional control calculations for water supply and space heating on the microcomputer. The water temperature can be stably controlled by driving the proportional control valve with the output of the heating mode processed by the hot water supply or heating section and the simultaneous mode switching processing section.

In addition, during simultaneous operation, the proportional control valve is driven preferentially by the simultaneous mode output using the output processed by the hot water proportional control calculation section to keep the water temperature stable, and the heating side receives the heating thermistor signal. By controlling the opening and closing of the heating solenoid valve during the ON-OFF control range, the heating water temperature can be controlled.

In addition, by using a small number of parts and a microcomputer to perform arithmetic processing for each mode, optimal water temperature control can be performed for each mode, and the purpose can be achieved at low cost.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic diagram of the configuration of the embodiment.

1 is a heat exchanger for hot water supply, which has a water supply port 1a and a hot water supply port 1.
b, and has a water supply detection element 22 in the water supply side passage that detects water supply and outputs a signal.

2 is a heating heat exchanger connected to a hot water return port 2a and a hot water outlet 2b. The heating hot water passage A is provided with a pump 3, an expansion tank 4, and a bypass pipe 5, and the expansion tank 4 has an overflow pipe 6. An exhaust pipe 7 is connected to each of the heat exchangers 1 and 2, and a forced exhaust fan motor 23 having fan blades 24 is provided to discharge combustion exhaust gas to an exhaust port 26 through an exhaust guide 25. Further, a part of the case 28 is formed so that combustion air can be supplied from the air supply port 27.

The fuel passage connects the main solenoid valve 8 and the proportional control valve 10 in series, branches from this and connects to the hot water supply burner 11 through the hot water supply solenoid valve 9, and connects the heating burner 15 through the heating solenoid valve 13. and configure.

A comparator 17 compares and calculates a signal from a thermistor 16 for hot water provided at the outlet of the hot water heat exchanger 1 and a signal from a hot water temperature setting device 18 such as a remote controller, and a hot water/heater provided in a microcomputer 31 performs a comparator 17 to compare and calculate the signal from the thermistor 16 for hot water provided at the outlet of the heat exchanger 1 for hot water and the signal from a hot water temperature setting device 18 such as a remote control. The proportional control valve drive unit 19 is operated by the hot water supply mode output processed by the hot water supply/heating/simultaneous mode switching processing unit 33 and the proportional control calculation unit 32, and the proportional control valve 10 is operated. The heating heat exchanger 2 is configured to control the hot water temperature so that the hot water temperature is constant by controlling the amount of combustion.
A comparator 29 compares and calculates the signal from the heating thermistor 20 provided at the outlet of the heating thermistor 20 and the signal from the hot water temperature setting device 30.
The proportional control valve drive unit 19 is operated by the output of the heating mode processed by the hot water supply/heating proportional control calculation unit 32 and the hot water supply/heating/simultaneous mode switching processing unit 33 provided in the microcomputer 31. The control valve 10 is operated to control the combustion amount of the heating burner 15 to control the temperature of the heating hot water at a constant temperature.

The hot water supply electromagnetic valve 9 and the heating electromagnetic valve 13 are configured to open when each hot water temperature is controlled.

In addition, when hot water supply and heating are used simultaneously, the signals of the hot water supply thermistor 16 and the heating thermistor 20 are compared with the comparators 17 and 29, and the hot water supply/heating proportional The proportional control valve drive unit 19 is operated with the output that has been subjected to the proportional control calculation process for hot water supply preferentially using the simultaneous mode output processed by the control calculation unit 32 and the hot water supply/heating/simultaneous mode switching processing unit 33. The proportional control valve 10 is operated to control the combustion amount of the hot water supply burner 11 to control the hot water temperature so that the outlet temperature is constant, and the combustion amount of the heating burner 15 is controlled in the hot water supply mode. The combustion amount is controlled by the proportional control valve 10 operated. Note that even if the microcomputer 31 receives a signal from the heating thermistor 20, it ignores it. Furthermore, when the heating load causes the ON-OFF control range, the signal from the heating thermistor 20 is processed by the microcomputer through the comparator 29, and the heating solenoid valve 13 is controlled to close or open. It is configured to control the temperature of heating hot water.

To explain the operation based on the flowcharts of FIGS. 2 and 3, the operation switch 41 of the control device
When the hot water heater (not shown) connected to the hot water supply port 1b is opened with the water heater turned on, the water supply detection element 22
Water supply is detected at , a hot water supply operation sequence is activated at hot water supply operation determination 42, and the forced exhaust fan motor 23 is rotated. When only the hot water supply mode is determined by the heating operation determination 43 (N of 43), the main solenoid valve 8, the proportional control valve 10, and the hot water supply solenoid valve 9 are opened based on the sequence of 44, 45, and 46, and the fuel is kept ignited. .
(The ignition/holding means is not particularly shown) The hot water supply heat exchanger 1 is heated by the combustion of the hot water supply burner 11, and the hot water is discharged from the hot water supply port 1b. The hot water supply temperature is detected by the hot water supply thermistor 16, and processed by the hot water supply/heating/simultaneous mode switching processing section 33 of the microcomputer 31 so that the hot water temperature is determined by the comparator 17 and becomes the hot water temperature set by the hot water temperature setting device 18. With the hot water supply mode output 47, the proportional control valve drive unit 19 is operated using a control signal programmed for PID or PI calculation in the hot water/heating proportional control calculation unit 32 (sequence 48), and the combustion amount of the hot water supply burner 11 is controlled. Control.

On the other hand, in the heating hot water passage A, a heating radiator and a bath reheating heat exchanger (not shown) are connected to the tips of the hot water outlet 2b and hot water return port 2a.

Switch heating operation signal, etc. (not shown)
When turned on, the heating operation sequence is activated in heating operation determination 49, and the pump 3 and forced exhaust fan motor 23 are rotated.

Based on the sequences 50, 51, and 53, the main solenoid valve 8, the proportional control valve 10, and the heating solenoid valve 13 are opened to ignite and hold the fuel. (Ignition and maintenance are not particularly shown) When the heating burner 15 burns, the heating heat exchanger 2 is heated, and hot water is circulated and supplied to a heating radiator etc. through the hot water outlet 2b.

The temperature of the circulating water is detected by the heating thermistor 20 and processed by the hot water/heating/simultaneous mode switching processing section 33 of the microcomputer 31 so that the hot water temperature reaches the temperature set by the comparator 29 and hot water temperature setting device 30. With the heating mode output 54, the proportional control valve drive unit 19 is operated (sequence 55) using a control signal programmed for PID or PI calculation in the proportional control calculation unit 32 for hot water supply/heating, and the proportional control valve 10 is operated. , controls the combustion amount of the heating burner 15.

Condition 1 of sequence 52 is heating burner combustion amount > heating load (even if the proportional control valve 10 is set to a small combustion amount, if the heating load is exceeded and the ON-OFF control range is reached, the heating thermistor 20 The circulating water temperature can be controlled by closing the heating solenoid valve 13 in sequence 56 and opening it in sequence 53 using a signal via the microcomputer 31.

In addition, when hot water supply and heating are operated simultaneously, the hot water supply and heating simultaneous operation mode is determined in sequence 43 (Y in 43), and based on the sequences 57, 58, and 59, the main solenoid valve 8, the proportional control valve 10, and the hot water supply The solenoid valve 9 is opened to ignite and hold the fuel.
At the same time, the heating solenoid valve 13 is opened based on sequences 60 and 61, and the simultaneous mode output 6 processed by the hot water/heating/simultaneous mode switching processing section 33 is activated.
2, the proportional control valve drive unit 19 is operated to preferentially control the combustion amount of the hot water supply burner 11 to control the hot water temperature, and the combustion amount of the heating burner 15 follows the combustion of the hot water supply burner 11. control.

When heating load is small (condition 1) Sequence 60
If the heating is in the ON-OFF control range,
The circulating water temperature can be controlled by opening the heating solenoid valve 13 in sequence 63 or opening it in sequence 61 using a signal from the heating thermistor 20 via the microcomputer 31.

Therefore, the opening and closing of the heating solenoid valve 13 is controlled by the signal from the heating thermistor 20.
This is done with an OFF control signal, and the hot water supply solenoid valve 9 is
It is configured to be opened and closed by a signal from the water supply detection element 22, and is configured to be controlled by a control signal suitable for each mode by a signal from a hot water supply, heating, and simultaneous mode switching processing section 33 of a microcomputer 31. It has been done.

The proportional control valve 10 has a pressure control valve section using a diaphragm, and a type that controls pressure by electromagnetic force is effective in the present invention.

The hot water supply/heating proportional control calculation unit 32 of the microcopy computer 31 controls the combustion amount of the hot water supply burner 11 and the heating burner 15 by driving the proportional control valve 10, and can perform optimal hot water temperature control for each. However, due to the program capacity of the microcomputer 31, the proportional control calculation program for hot water supply cannot be used as is.
It is also possible to adequately control the heating water temperature without incorporating a heating calculation program.

This is because heating hot water does not have sudden load fluctuations like hot water supply, so even if the same calculation program is used, there is no problem in operation. By doing so, the cost of the microcomputer 31 can be reduced. It is also possible to make it cheaper.

Effects of the Invention As described above, the present invention provides a hot water supply burner and a heating burner branched from the proportional control valve, and controls each heat exchanger by the proportional control valve drive unit through the hot water supply and heating proportional control calculation units. Since the water temperature can be controlled, it has the following effects.

(1) For both hot water supply and heating, a single proportional control valve proportionally controls the amount of combustion to control the hot water temperature, making it possible to stabilize the hot water temperature.

(2) In particular, since the heating water temperature can be controlled by proportional control, energy savings can be achieved compared to conventional hot water temperature control using Hi-Lo-OFF control.

(3) Optimal hot water temperature control can be performed using signals from the proportional control calculation unit for hot water supply and heating.

(4) Based on the signals from the mode switching processing section, the hot water temperature control on the hot water supply side can be optimally controlled both in individual control as well as in the simultaneous use mode, and the heating water temperature can also be sufficiently controlled as hot water, making it possible to use the hot water supply/heating switching system. It is comparatively advantageous.

(5) The number of parts in the fuel passage is small and there is only one hot water temperature control circuit, resulting in lower costs.

[Brief explanation of the drawing]

The drawings show a hot water temperature control device for a 2-can, 2-water hot water heater. Fig. 1 is a schematic diagram of the configuration of a conventional example, Fig. 2 is a schematic diagram of the configuration of an embodiment of the present invention, and Fig. 3 is the same diagram. It is an operation flowchart of an example. 1... Heat exchanger for hot water supply, 2... Heat exchanger for heating, 8... Original solenoid valve, 9... Solenoid valve for hot water supply, 10
...Proportional control valve, 11...Hot water supply burner, 15...
... Burner for heating, 16 ... Thermistor for hot water supply, 1
7... Comparator (for hot water supply), 19... Proportional control valve drive unit, 20... Thermistor for heating, 29... Comparator (for heating), 31... Microcomputer,
32...Proportional control calculation unit for hot water supply/heating, 33...
...Hot water supply/heating/simultaneous mode switching processing unit.

Claims (1)

[Claims] 1. A heat exchanger for hot water supply, a heat exchanger for reheating or heating, a burner for hot water supply and a heating burner that heat each of these heat exchangers, and a solenoid valve for hot water supply connected to the burner for hot water supply and for heating. a heating solenoid valve connected to the burner; a proportional control valve commonly connected to the hot water supply and heating solenoid valves;
A hot water supply thermistor provided at the outlet of the hot water supply heat exchanger and a heating thermistor provided at the outlet of the heating heat exchanger are connected to both these thermistors via respective comparators, and the signals of the two thermistors are respectively connected. A microcomputer has a proportional control calculation unit for hot water supply/heating that receives water through a comparator, a hot water supply/heating/simultaneous mode switching processing unit, and a proportional control valve drive unit connected to the output side of this microcomputer. A hot water temperature control device for a two-can, two-water hot water heater that controls the combustion amount of each of the burners by driving a control valve.