JPH0424353Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application and overview of the invention] The present invention is a water heater anti-freeze device, in particular, a water heater that heats and insulates the water circuit in winter. This is an antifreeze device that prevents freezing, and when the inside of the water circuit that is being heated reaches a high temperature due to heat generation from a gas burner when the device is in use, the heat retention heater stops generating heat regardless of the outside temperature. This is to reduce wasteful power consumption.

[Prior art and its problems] In a water heater that is not in use, water in the water circuit remains in a stagnant state, so when the outside temperature drops in winter, the water in the water circuit freezes. May damage piping.

Therefore, as shown in FIG. 7, there is a system in which the water circuit of a water heater is heated and kept warm by a heater to prevent the water in the water circuit from freezing.

That is, first heaters 31, 31, 31 are disposed in the water pipe 2 constituting the water circuit, at its inlet portion 21, outlet portion 22, and portion 23 exiting from the heat exchanger 1. Second heaters 32, 32 for heating and keeping the inside of the water pipe 2 near the heat exchanger 1 warm are attached to the water circuit 2 of the can body 10 on the upstream side of the heat exchanger 1. In addition, each of the heaters 31, 31, 32, 32 is turned on and off by the temperature sensor 4 installed at the bottom of the device.
It is controlled to be OFF.

In this conventional system, when the outside temperature drops to the extent that the inside of the water pipe 2 freezes, the first and second heaters 31, 31, 32, and 32 generate heat based on the output of the temperature detector 4, causing the water inside the water pipe 2 to cool. to prevent it from freezing.

However, the above-mentioned conventional device has a problem in that it wastes a lot of power.

This is because even if the inside of the water pipe 2 near the heat exchanger 1 is heated and heated by the combustion of the gas burner 5, etc., so that heating and keeping warm by the second heaters 32, 32 is not necessary, the outside temperature freezes. As long as the temperature is below
This is because the second heaters 32, 32 are left in the energized state.

That is, when the outside temperature is below the freezing temperature, even if the inside of the water pipe 2 in the second heater 32, 32 installation area (near the heat exchanger) is in a high temperature state during or immediately after using the appliance, A second heater 3 for keeping the area warm
2 and 32 will generate heat unnecessarily, and power will be wasted.

[Technical Problem] The present invention is based on ``disposing the second heaters 32, 32 in the water circuit part of the heat exchanger 1 or in the vicinity of the heat exchanger 1 in the appliance, is equipped with a plurality of first heaters 31, 31, and further includes the first heaters 31, 31 and the second heaters 32, 32.
is a water heater antifreeze device that is controlled on and off by the output of a temperature detection switch installed inside the appliance.In order to reduce unnecessary power consumption, one part of the heat exchanger is The technical problem is to stop the second heaters 32, 32 from generating heat when the water circuit is located at a high temperature.

[Means] The technical means of the present invention for solving the above problem is described using the conceptual diagram shown in Fig. 1.The technical means of the present invention is as follows. A first temperature detection switch 41 having an operating temperature and a second temperature detection switch 42 having an operating temperature set higher than the first temperature detection switch 41 are provided, and each temperature detection switch 41, 42 is configured to turn on at a temperature below the operating temperature. and the first heater 31
The output of the first temperature detection switch 41 is applied to the other second heater 32, 32.
Temperature detection switch 41 and second temperature detection switch 4
The AND output of 2 is applied, and the heat sensing part of the second temperature detection switch 42 senses the water circuit part of the heat exchanger 1 or its vicinity, and the heat sensing part of the other first temperature detection switch 41 senses the outside temperature of the appliance. Each was placed in an easily accessible location.

[Effect] The above technical means works as follows.

When the outside temperature drops to the freezing temperature of water when the appliance is not in use, two temperature detection switches 41, 4 are activated.
2 are both in the ON state, and each of these switches
The AND output is applied to the second heaters 32, 32, and the second heaters 32, 32 generate heat. That is, the heat exchanger 1 and the water circuit portion in the vicinity thereof are heated and kept warm by the second heaters 32, 32, and are prevented from freezing.

At the same time, the output of the first temperature detection switch 41, which is in the ON state, is also applied to the first heaters 31, 31 attached to the water circuit located in parts other than the heat exchanger 1. 1 heater 31,
31 also generates heat, and freezing in the water circuit of this part is also prevented.

Therefore, in the water circuit inside the appliance, the heat exchanger 1 part and other parts are heated and kept warm by the first heater 31 and the second heaters 32, 32, so freezing is prevented at low temperatures such as in winter. It becomes possible.

Next, when using a device that burns the gas burner 5 or immediately after using the device, the water circuit of the heat exchanger 1 or the second heater 32, 32 located near the heat exchanger 1 is heated. , the temperature of the second temperature detection switch 42 is higher than the operating temperature of the second temperature detection switch 42.
becomes OFF. From this, it can be seen that the second temperature detection switch 42 and the first temperature detection switch 41
Since the AND condition is no longer satisfied, the second heaters 32, 32 near the heat exchanger 1, which were energized by the AND output, no longer generate heat. That is, when the water circuit located in the heat exchanger 1 section reaches a high temperature state due to the combustion of the gas burner 5, the second heaters 32, 32 that heat the section are stopped from generating heat.

Next, after a while after the gas burner 5 is extinguished, the inside of the water circuit near the heat exchanger 1 cools down.

When the inside of the water circuit near the heat exchanger cools down, a second temperature detection switch 4 detects the temperature of the part and operates.
2 is turned ON again, and the AND of the second temperature detection switch 42 and the first temperature detection switch 41 is again performed.
When the conditions are met, the second heaters 32, 3 are activated in the same way as above.
2 generates heat and heats and keeps the water circuit portions near the second heaters 32 and 32 warm.

Also, if the second heaters 32, 32, 32 generate heat and the temperature inside the circuit of the heat exchanger 1 portion rises more than necessary, the second temperature detection switch 42 detects this temperature and the second heater 32, 32. Prevents unnecessary heat generation.

[Effect] The system uses outside temperature detection to control multiple heaters attached to the water circuit to prevent freezing.
Compared to systems that detect the temperature of the water circuit inside the water heater, the anti-freeze function of the entire anti-freeze system has better sensitivity, and it is also possible to detect when the water heater is in operation or immediately after it has stopped operating. a certain period of time, etc.
When the inside of the water circuit located in the heat exchanger 1 is in a high temperature state, at least the second heaters 32, 3
Since the heat generation of 2 is reliably stopped, wasteful power consumption can be suppressed.

[Example] Next, an example of the present invention described above will be described in detail with reference to the drawings.

As shown in FIG. 2, the water pipe 2 constituting the water circuit in the water heater is attached with first heaters 31, 31 and second heaters 32, 32, similar to the conventional ones described above. , a first part with an operating temperature set to 0°C is located at the lower part of the appliance where it is easy to sense the outside temperature.
A heat sensitive part 43 of a temperature detection switch 41 is located there. Further, the heat sensitive part 44 of the second temperature detection switch 42, which has an operating temperature set higher than that of the first temperature detection switch 41, is attached to the water pipe 2 located in the heat exchanger 1 section. In this case, the heat-sensitive portion 44 of the second temperature detection switch 42 is located near the exhaust port 6 where cold air is easily blown in and cooled when there is wind.

Specifically, each of the above parts is electrically wired as shown in FIG. The output of the first switch 61 is applied to the base of the switch 61, and the output of the first switch 61 turns the first heaters 31, 31 on and off.
It is applied to the input part of the third switch 63 (using a switching transistor) which is turned off.

Further, the second temperature detection switch 42 includes a second thermistor 72, a second switch 62, and a resistor 52.
The output is applied to the NAND circuit 51 together with the output of the first temperature detection switch 41. and,
The second thermistor 72 corresponds to the heat sensitive part of the second temperature detection switch 42 described in the technical means described above.

The output of the second thermistor 72 is amplified by an amplifier circuit 55, and the amplifier circuit 55 is turned on and off by a fifth switch 65, which is turned on and off by the output of the NAND circuit 51. It's becoming controlled.

The output of the second thermistor 72 amplified by the amplifier circuit 55 is then sent to the Schmitt circuit 4.
The output of the Schmitt circuit 46 is applied to the fourth switch 64, which turns on and off the second heaters 32, 32.
It is starting to be turned off.

In this device, by appropriately setting the values of the first resistor 53 and the first thermistor 71, the first switch 61 is activated when the outside temperature drops to 0°C.
By appropriately selecting the values of the second resistor 52 and the second thermistor 72, the second switch 62 is set to turn on when the temperature is below 45°C. be.

Further, by appropriately setting the values of the respective resistors of the Schmitt circuit 46, the output of the Schmitt circuit 46 becomes "L" when the output of the second thermistor 72 indicating that the temperature has reached 40°C or higher is received. When the second thermistor 72 outputs an output indicating that the temperature has fallen below 15°C, an "H" output is produced. Therefore, the fourth switch 64 to which the output of the Schmitt circuit 46 is applied is connected to the fourth switch 64 when the outside temperature is 40°C.
It turns off when the temperature is above ℃, and turns on when the temperature falls below 15℃.

Now, when the outside temperature drops when the appliance is not in use, first the first switch 61 constituting the first temperature detection switch 41 is turned on, and the first
The third switch 63 is activated by the output of the switch 61.
The first heaters 31, 31 generate heat in the ON state. As a result, the 2 portions of the water pipes other than the 1 portion of the heat exchanger are heated and kept warm.

At the same time, the second thermistor 72 also detects a drop in the outside temperature, so the second switch 62 constituting the second temperature detection switch 42 is turned on, and the output on the emitter side of the second switch 62 becomes NAND.
applied to circuit 51.

Not only the output of the second switch 62 but also the output of the first switch 61 mentioned above is applied to the NAND circuit 51, and both the first switch 61 and the second switch 62 are in the ON state. (H
output), so the NAND circuit 51
An "H" signal is input to both of the two input terminals.

When the "H" signal is input to the two input terminals of the NAND circuit 51, the "L" signal is output from the NAND circuit 51, which is the fifth
The voltage is applied to the switch 65, the amplifier circuit 55 provided on the collector side of the fifth switch 65 becomes conductive, and the amplified signal of the second thermistor 72 is applied to the Schmitt circuit 46.

Since the Schmitt circuit 46 outputs an "H" signal under a temperature condition of 15 degrees Celsius or lower, if the outside temperature has dropped to freezing temperature when the appliance is not in use, as shown in FIG. The Schmitt circuit 46 outputs "H". Then, the "H" signal is applied to the fourth switch 64 and the second heater 3
2 and 32 become energized. That is, a second heater 32 that heats the water pipe 2 located in the heat exchanger 1 portion;
32 generates heat and prevents that part from freezing.

Next, the combustion of the gas burner 5 and the second heater 32,
When the temperature of the water pipe 2 located in the heat exchanger 1 portion rises to 40°C due to the heat generated by
applied to switch 64. That is, the second heater 3
2 and 32 stop generating heat, thereby preventing wastage of power.

After that, after the gas burner 5 is extinguished, the heat exchanger 1
When the temperature of the water pipe 2 located in that part decreases and the temperature of the part where the second thermistor 72 is installed falls to 15°C, the Schmitt circuit 46 again outputs the "H" signal, and the second heater 32, 32 will generate heat.

In the second embodiment shown in FIG. 5, the first switch 6 is turned on by the output of the first thermistor 71.
A second thermistor 72 is inserted into the first collector circuit, and the output of the second thermistor 72 is applied to the Schmitt circuit 46.

In this device, when the outside temperature reaches 0°C, the first switch 61 turns on and the second thermistor 7
2 begins to be applied to the Schmitt circuit 46. Then, the output of the second thermistor 72 that detects the water temperature in the water circuit near the heat exchanger 1 is processed by the Schmitt circuit 46, and the second heater 32,
32 is controlled to be ON/OFF.
In this case as well, by appropriately setting the values of the respective resistances in the Schmitt circuit 46, the second heaters 32, 32 can maintain the temperature in the water circuit near the heat exchanger 1.
It is designed to stop generating heat when the temperature reaches 40℃ or higher, and to start generating heat when the temperature drops to 15℃ or lower.

In addition, in the above embodiment, the second heaters 32, 32 are
The temperature at which the second heaters 32, 32 are turned on and off was changed so that the heat generation stopped at 40 degrees Celsius or higher and the heat generation started at 15 degrees Celsius or lower, but by adopting a circuit as shown in FIG. The heaters 32, 32 may be turned on and off using one reference temperature set in the second temperature detection switch 42 as a boundary.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram of the present invention, Fig. 2 is a schematic diagram of a water heater, Fig. 3 is an electric circuit diagram, and Fig. 4 shows the operation timing of the second thermistor 72 and the second heaters 32, 32. Time chart, Fig. 5 is an explanatory diagram of the second embodiment, Fig. 6 is an explanatory diagram of the third embodiment, and Fig. 7 is an explanatory diagram of the conventional example. ...First heater, 32, 32...Second
Heater, 41...First temperature detection switch, 42...
...Second temperature detection switch.

Claims (1)

[Scope of utility model registration request] A second heater is disposed in the water circuit portion of the heat exchanger 1 or in the vicinity of the heat exchanger 1 in the appliance, and a plurality of first heaters are attached to the water circuit portion remote from the heat exchanger 1, and further, The first heater and the second heater are controlled by the output of a temperature detection switch installed inside the device.
In an antifreeze device for a water heater that is controlled to be ON/OFF, a first temperature detection switch 4 having an operating temperature that approximately corresponds to the freezing temperature of water is installed in the device.
1 and a second temperature detection switch 42 having an operating temperature set higher than this, each temperature detection switch 41, 42 is set to turn on at a temperature below the operating temperature, and the first heater has a first At the same time, the output of the temperature detection switch 41 is applied, and the AND output of the first temperature detection switch 41 and the second temperature detection switch 42 is applied to the other second heater. A water heater anti-freeze device in which the heat sensitive part of the other first temperature detection switch 41 is located in the water circuit part of the exchanger 1 or its vicinity at a location where it can easily sense the outside temperature of the appliance.