JPS649541B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a hot water circulation type hot water heater, and particularly aims at simplifying the circuit configuration and reducing the running cost of the appliance. In the above-mentioned hot water heater, in order to reduce the number of blinks of the burner, which is the heat source, when the circulating hot water temperature reaches a predetermined first set temperature a, as shown in FIG. In the first combustion loop 1, when the hot water temperature decreases due to weak combustion and reaches the second set temperature b, strong combustion is performed again, and even in the above-mentioned weak combustion, the hot water temperature further increases and reaches the third set temperature c. Then, combustion is stopped, and when the hot water temperature decreases and reaches a fourth set temperature d, which is slightly higher than the second set temperature b, the second combustion loop 2 performs weak combustion,
There are some systems that perform temperature control by switching to the first combustion loop 1 when the hot water temperature during weak combustion reaches the second set temperature b, and switching to the second combustion loop 2 when it reaches the second set temperature c.

However, with the temperature control described above, there is a problem in that the number of switching between strong, weak, and stop is increased depending on the temperature of the room to be heated, that is, the load conditions, resulting in a reduction in the lifespan of the solenoid valve and the like.

The present invention has been developed in view of the above-mentioned problems, and will be described below first with reference to FIG. 2. 3 is a hot water circulation circuit, which includes a heat absorber 5 heated by a gas burner 4;
A heating radiator 6, an open water storage tank 7, and a circulation pump 8 are arranged in this order. Further, a pair of solenoid valves 10 and 11 are connected in parallel to the fuel passage 9 to the gas burner 4, respectively. Note that the solenoid valves 10 and 11 may be connected in series and a bypass flow path may be provided in the downstream solenoid valve.

12 is a temperature control circuit which connects the output of a hot water temperature detector 13 consisting of a thermistor for detecting the hot water temperature in the hot water circulation circuit 3 to one input 15 of a comparator 14, and has a switching function for the output of this comparator 14. The output 18 of the microcomputer 16 is connected to the other input 17 of the comparator 14 via a D/A converter 19. Furthermore, the output 20 of the microcomputer 16 is connected to the solenoid valves 10 and 1 via a solenoid valve control circuit 21.
1 is connected to the input 23, and the output of a room temperature detector 22 consisting of a thermistor or the like for detecting room temperature is connected to the input 23.

FIG. 3 shows the control characteristics of the hot water temperature of the hot water circulation circuit 3, showing the first combustion loop 24 for high-temperature operation and the second combustion loop 25 for low-temperature operation, each having the same set temperature range. These will be explained using the first combustion loop 24.

First, when the hot water temperature reaches the first set temperature a due to strong combustion in the gas burner 4, one solenoid valve 10 is closed to cause weak combustion in the gas burner 4, as shown in steps 1 and 2 in FIG. In step 3, it is determined whether or not the hot water temperature has decreased and reached the second set temperature b or less, and if it is below, in step 4, the electromagnetic valve 10 is opened to cause strong combustion in the gas burner 4. If it is not lower than the second set temperature b in step 3, it is determined in step 5 whether the temperature has risen to higher than the third set temperature c, and if it is higher than the third set temperature, then in step 6 the other electromagnetic The valve 11 is also closed to stop combustion in the gas burner 4, and if the temperature has not reached the third set temperature or higher, the process returns to step 2 to continue weak combustion.

When the hot water temperature reaches the fourth set temperature d or lower due to the combustion stop in step 6, this is determined in step 7 and the gas burner 4 is slightly combusted (step 8), after which the process returns to step 2.

The second combustion loop 25 has the same temperature range as the first combustion loop 24, that is, the temperature difference between the first to fourth set temperatures is the same, and each set temperature is set lower by a predetermined amount α.

On the other hand, as shown in FIGS. 4 and 6, the combustion loops 24 and 25 first determine in step 9 whether or not the temperature in the room where the heating radiator 6 is installed is lower than the fifth set temperature e. , then step 10
and proceeding to the first combustion loop 24 for the high temperature operation.
Perform high temperature operation. Then, it is determined in step 11 whether or not the room temperature has risen due to this high-temperature operation and reached the sixth set temperature f, and if it is higher than that, the combustion is stopped in step 12, and this combustion stop causes the room temperature to decrease. Then, in step 13, it is determined whether or not the temperature is lower than the seventh set temperature g, and if it is below, the process proceeds to step 14, where low-temperature operation is performed using the second combustion loop 25 for low-temperature operation.

Further, if the room temperature rises due to the low-temperature operation in step 14, it is determined in step 15 whether or not the temperature is higher than the sixth set temperature, and if it is above, the process returns to step 12 to perform low-temperature operation. When the value decreases, the process returns to step 9 and the fifth
It is determined whether or not the temperature has reached the set temperature e or lower, and if it is lower than the set temperature e, the process proceeds to step 10 and high temperature operation is performed.

With this control, when the heating load is low, the temperature is controlled at a low temperature, so that the burner 4 can be
Solenoid valve 10, 1 that can have a long weak switching cycle
In addition to improving the durability of 1, when the heating load is large, by controlling the combustion loop with a high set temperature, it is possible to perform comfortable heating with little temperature change. Furthermore, by setting the set temperature difference of the combustion loop to be the same, by simply shifting the reference voltage of the comparator 14 outputted from the microcomputer 16 (this is done in the embodiment of the present invention), the temperature data becomes the same. It can be controlled using a setting circuit or a program, which simplifies the circuit configuration. That is, in FIG. 2, the other input 1 of the comparator 14
7 by changing the output of the microcomputer 16,
By shifting according to the temperature difference, all set temperatures can be compared.

In the embodiment, two combustion loops are set, but the number may be increased. In that case, the number of combustion loops can be easily set without increasing the number of circuit components.

As described above, the hot water heater control device according to the present invention includes a plurality of combustion loops with different set temperatures, each of which controls the burner to be strong, weak, or stopped by comparing the set temperature with the circulating hot water temperature. These combustion loops are selectively switched according to the room temperature, and by controlling the circulating hot water temperature according to the heating load, it reduces the number of times the burner status is changed and improves the durability of the solenoid valves, etc. You can improve.

In addition, by configuring the set temperature difference of each combustion loop to be the same, there is no need to provide a large number of set temperature data for each combustion loop, and this allows the temperature settings of the high-temperature side and low-temperature side combustion loops to be set using the same comparator. The circuit configuration can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a conventional characteristic diagram, FIG. 2 is a schematic configuration diagram of the present invention, FIGS. 3 and 4 are characteristic diagrams, and FIG.
FIG. 6 and FIG. 6 are also flowcharts. 3...Hot water circulation circuit, 4...Gas burner, 9...
... Fuel flow path, 10, 11 ... Solenoid valve, 12 ... Temperature control circuit, 13 ... Hot water temperature detector, 22 ... Room temperature detector, 24 ... First combustion loop, 25 ... Second combustion loop.

Claims (1)

[Claims] 1. Compare the output from a hot water temperature detector that detects the temperature of circulating hot water for heating with a set temperature, and when the hot water temperature reaches the set temperature, In a device equipped with a combustion loop that controls the opening and closing of a solenoid valve to control at least strong, weak, and stop combustion of the burner, a plurality of the above-mentioned combustion loops are provided with different set temperatures, and these plurality of combustion loops are used for heating and heating. 1. A control device for a hot water heater, comprising a switching means that switches based on a detection output from a room temperature detector that detects the temperature in a room in which a radiator is installed. 2. The control device for a hot water heater according to claim 1, wherein the temperature differences between the combustion loops are the same in the set temperatures for strong, weak, and stop control.