JPS6259335A - Water heater - Google Patents

Abstract

PURPOSE:To provide a water heater provided with a function to detect the lowering of the atmospheric pressure to stop the power supply to a heater by attaching to the heater an atmospheric pressure sensor for sensing an atmospheric pressure suited to bring forth a boiling point which is slightly lower than the boiling point of water and stopping the power supply based on the sensed signal. CONSTITUTION:When an atmospheric pressure sensor senses an atmospheric pressure which is lower by 0.09kg/cm<2> than the atmospheric pressure on each sea level, that is, the lowering of the boiling point of water by approximately 3 deg.C, it turns off the electric contact thereof. A microswitch 33 as the electric contact is connected in series, together with a thermostat 23, to a power supply circuit to main relay 22 for turning ON or OFF of the power supply to a water heating band heater 20. Therefore, in a case where, despite a fact that the thermostat 23 which is turned OFF when the temperature of hot water rises to 95 deg.C or more, is turned ON, the atmospheric sensor senses the lowering of the atmospheric pressure suited to lower the boiling point of water by approximately 3 deg.C, the power supply circuit to the main relay 22 is opened, and the power supply to the band heater 23 is stopped. Thus, despite a fact that the temperature of hot water is 95 deg.C or less, not to mention 100 deg.C, a possibility of bumping due to a boiling point lowering phenomenon can be prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention has a built-in heater for heating water that is free from the risk of sudden boiling due to the boiling point depression phenomenon even when used at high altitudes. Regarding pot-type water heaters.

[Conventional technology] A pot-type water heater that incorporates a water heater with a thermostat is extremely useful because it can draw out hot water that is always kept at a constant temperature just by connecting the heater to a power source. Because they are so convenient, they are now being used not only at home, but also in cars to make leisure activities more comfortable and for outdoor workers to relax.

[Problems to be Solved by the Invention] If you load a water heater like the one described above into your car and go to a recreational area, the elevation of famous sightseeing spots will be 2.5 m. It is not uncommon for roads to reach high altitudes as high as 000m, so if the operating temperature of the thermostat to maintain a constant water temperature is set to 95°C, for example, if the temperature is 95°C,
If you climb to a high altitude of 500 m above sea level, water will begin to boil at around 92 degrees Celsius due to the boiling point depression phenomenon, and the boiling prevention function of the thermostat will not be utilized at all, so when you pour hot water from the water heater, the strong vapor pressure will cause the water to splatter. Hanging on your hand,
Not only is there a danger that the area near the steam escape hole provided at the top of the water heater may become too hot, but the generated steam may fog up the window glass, causing inconvenience.

In response to the phenomenon in which the boiling point of water drops at high altitudes, the present invention has a function that can stop the power supply to the heater by detecting a drop in atmospheric pressure before boiling occurs due to the drop in the boiling point. The purpose is to provide water heaters.

[Means for Solving the Problems] In order to achieve the above object, the water heater of the present invention includes a heat-retaining hot water storage bot, a heater for heating water, and controlling the energization of the heater to adjust the temperature of the water. In a water heater that incorporates a temperature sensor to maintain the temperature at a set temperature, an atmospheric pressure equivalent to a boiling point slightly lower than the boiling point of water is sensed, and electricity to the heater is stopped based on this sensing signal. A configuration was adopted in which a barometric pressure sensor was attached to the system.

[Function] When a water heater with the above configuration is used in a place with low atmospheric pressure, such as at a high altitude, it will produce water at a temperature slightly lower than the boiling point of water at that atmospheric pressure. When the barometric pressure sensor detects the pressure equivalent to causing boiling, it stops energizing the heater even if the water temperature in the water heater is below the set temperature, thus preventing dangerous sudden boiling due to the phenomenon of lowering the boiling point of water. is prevented.

[Example] A specific configuration of the present invention will be described below based on an example shown in the accompanying drawings.

In Figs. 1 to 4 showing the structure of a water heater as an embodiment of the present invention, 1 and 2 respectively indicate a stainless steel water storage container which is the main body of a heat-retaining hot water storage pot, and w.
4I! J's exterior casing, and a gap is provided between the two for attaching a heater, a sensor, etc., and for heat retention. 3 is hot water stored in the container 1.

4 is an inner lid of the container 1 made of stainless steel, and 5 is an outer lid fitted to the outer casing 2 and made of synthetic resin. 6 is a bellows-type air pump for pumping hot water, which is assembled inside the outside N5 with a built-in spring 8 made of stainless steel. 7 is a push button for operating the pump 6, and 9 is a ventilation path connecting the pump 6 and the space inside the container 1. 10 is a stainless steel pipe for pumping out hot water, 11 is a spout at the tip of pipe 10, 12 and 13 are ball valves for checking the hot water, and 14 and 15 are gaskets for preventing leaks from the air shaft and the filter, respectively. These parts are assembled to a synthetic resin member 4a which is integrally joined to the stainless steel inner cover 4, as shown in FIG. 16
17 is a mounting bracket for supporting the container 1 above the bottom lid 16; 18 is a hinge for mounting the outer lid; 19 is a steam escape hole; , and 26 is a carrying handle.

Reference numeral 20 denotes a band heater 2 closely attached to the lower outer periphery of the container 1;
3 is a thermostat that functions as a temperature sensor to maintain the water temperature at a set temperature by intermittent supply of electricity to the heater 20;
22 is a main relay for turning on and off electricity of the heater 20;
4 is a harness, 25 is a power outlet, 28 is a power cord plug, 27 is a water meter, and 42 is a mounting bracket for an atmospheric pressure sensor.

In FIGS. 3 and 4 illustrating the structure of an atmospheric pressure sensor, 30 is a pressure sensing element, 33 is a microswitch as an electrical contact, and the pressure sensing element 30 deforms as the atmospheric pressure changes. It operates on and off in response to the current.

The pressure-sensitive element 30 is constructed by maintaining a vacuum inside a disc-shaped sealed case 31 formed by bonding two bellows-shaped diaphragms made of thin plates such as phosphor bronze or stainless steel, and injecting a small amount of water 32. It has an injected configuration.

The contact on/off knob 34 of the micro switch 33 is
The pressure-sensitive element 30 is placed opposite to the center of the upper surface of the case 31 with some gap in between. When a portion of the water vapor 32a is vaporized, the case 31 expands and deforms, pushing the knob 34 and turning off the contact of the microswitch 33. Then, when the atmospheric pressure drops again, the pressure sensitive element 30
The case 31 contracts and deforms to return the contact to the on state.

35 and 36 are input/output terminals of the microswitch 33.

The structure of the pressure-sensitive element 30 and the case 31 are such that the barometric pressure sensor turns off its electrical contact when it senses a pressure that is somewhat lower than the barometric pressure of the place where the sensor is placed, for example, by 0.09 kg/cm2. The positional relationship with the switch knob 34, etc. are set in advance. The boiling point of water is the 6th
As seen in Figure 7 and Figure 7, it decreases almost in proportion to the decrease in atmospheric pressure, and the above 0.09kO/C1
A drop in pressure of 112 degrees causes a drop in boiling point of about 3 degrees Celsius, so
This atmospheric pressure sensor functions as a kind of temperature sensor, detecting changes in atmospheric pressure and notifying that the boiling point of water has gone up or down only within a certain temperature range (in this case, about 3 degrees Celsius).

FIG. 5 is a circuit diagram for controlling the supply of electricity to the heater 20 for heating water, and 21 is a power switch, which is provided in a power supply circuit that is supplied with electricity only when the ignition switch of the automobile engine is turned on.

22 is a main relay, 22a is its contact, 20 is a band heater for water heating, 23 is a thermostat for keeping the water temperature constant, 33 is a microswitch that constitutes the electrical contact of the barometric pressure sensor, 37 and 38 are light emitting diodes, 40 is a temperature fuse, and +B is a wiring connected to the vehicle battery power source.

Next, regarding the operation of the above-mentioned water heater, graph A of the relationship between atmospheric pressure and the saturated steam temperature of water is shown in Figure 6, graph B of the relationship between altitude above ground and atmospheric pressure is shown in Figure 7, and The following description will be made with reference to a relationship graph C between ground altitude and saturated steam temperature and a relationship graph D between ground altitude and set hot water temperature drawn in FIG. 8.

As the altitude above sea level increases, atmospheric pressure gradually decreases from the value of 1 atm at sea level, as shown in graph B of FIG. As the atmospheric pressure decreases, the boiling point of liquids decreases, so the saturated vapor temperature of water, or in other words, the boiling point of water, decreases approximately in proportion to the decrease in atmospheric pressure, as shown in graph A in Figure 6. and lowered. Therefore, as the altitude above the ground increases, the saturated vapor temperature, or boiling point, of water decreases almost linearly, as shown in graph C in FIG.

For this reason, in the case of a water heater whose water temperature is set to, for example, 95°C on the assumption that it will always be used under normal pressure of 1 atm, as can be understood by referring to Figure 8. In places where the altitude is about 1,500 m or more, the thermostat 23, which has the role of turning on and off the electricity to the heater 20 to maintain the water temperature at 95°C, turns off the electricity to the heater 20. However, due to the phenomenon of boiling point depression, it suddenly begins to boil, resulting in the inconveniences mentioned at the beginning.

In the water heater according to the present invention, the power switch 21 is turned on to enter the operating state, and the band heater 20 is energized by turning on the contact 22a of the main relay to start boiling water. Under this state, the light emitting diode 37 lights up to indicate that the water heater is energized. When the constant temperature holding temperature set for WA warm reaches, for example, 95 degrees Celsius, the constant temperature holding thermostat 23 is activated and the power supply to the heater 20 and the light emitting diode 37 is stopped, and the hot water temperature is changed to the middle white with the set temperature. The light emitting diode 38 lights up to indicate that the temperature is maintained. If the water temperature decreases due to heat loss through the wall of container 1, thermostat 2
3 functions within its operating hysteresis loop, so the set water temperature continues to be maintained from then on.

After such usage, when the water heater installed in the car is gradually lifted up with the car towards an altitude of 1,500,111 or higher, the atmospheric pressure decreases accordingly, so the atmospheric pressure sensor is 0 from the atmospheric pressure at each altitude
．． 09k (1/Cm2) When it senses a lower atmospheric pressure, and accordingly detects that the boiling point of water has dropped by about 3°C as mentioned above, it turns off the electrical contact. band heater 20
Since it is connected in series with the thermostat 23 to the energization circuit for the main relay 22 for on/off energization,
Even though the thermostat 23, which turns off when the water temperature rises to 95 degrees Celsius or higher, is turned on, the barometric pressure sensor detects a drop in air pressure equivalent to lowering the boiling point of water by about 3 degrees Celsius at each altitude. In this case, the energizing circuit to the main relay 22 is opened and the energizing to the band heater 20 is stopped, thereby preventing the risk of boiling due to boiling point depression even though the water temperature is not only 100°C but also below 95°C. Ru. When the vehicle descends again toward low ground, the barometric pressure sensor turns on the contact when the above-mentioned operating conditions are met.

In other words, the electric circuit in Figure 5 is a water heater! 1. No matter how high the altitude is, the temperature of the water in the container 1 can be determined by graph D in Figure 8.
As shown in Figure 8, the boiling point of water at each elevation point (8th
Saturated steam temperature = boiling point of water, shown as graph C in the figure)
It plays a role in keeping the temperature about 3℃ lower at all times.

This temperature difference of 3 degrees Celsius is an arbitrarily determined value that takes into account uncertain factors such as variations in the sensitivity of the barometric pressure sensor, and the point is that if the water temperature can be maintained below the boiling point of water at each altitude, then the invention can be applied. For example, the temperature may be 2°C or 4°C.

The specific structure of the atmospheric pressure sensor shown in the above embodiment is merely an explanation of one embodiment.
In short, the atmospheric pressure is somewhat lower than the atmospheric pressure at the location where the water heater is used, for example, 0.1 km cn below the actual atmospheric pressure at that location.
It is equipped with a function of detecting the atmospheric pressure lower by +2 in advance, and it is sufficient to transmit this atmospheric pressure information to the means for turning on/off electricity to the heater for heating water in the hot water storage bot, for example, the main relay 22. Therefore, it is also possible for this atmospheric pressure sensor to also serve as the thermostat 23.

[Effect of the invention] A water heater having the above configuration can be used, for example, at an altitude of 1
When using a water heater with a built-in thermostat and heater in a place with low atmospheric pressure, such as over 500 m, the water temperature should be lower than the thermostat's set operating temperature (100°C).
Whereas there was a danger that water would suddenly start boiling due to the boiling point depression phenomenon even if the water had not reached (lower temperature).
The water heater of the present invention takes into account the drop in boiling point due to a drop in atmospheric pressure, and is equipped with a function that automatically stops energizing the heater when the water temperature reaches a temperature somewhat lower than that at which the above-mentioned bumping phenomenon occurs. It is possible to avoid dangers such as hot water scattering due to strong steam pressure when pouring hot water or fogging of window glass due to steam when installed in a car.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of the water heater according to the present invention, Fig. 2 is an external view including a partially broken surface, and Fig. 3 is a state in which the barometric pressure sensor incorporated in the water heater is placed under normal pressure. 4 is a side view including a partial cross section showing the state under pressure lower than normal pressure, and FIG. 5 is an illustrative diagram of an energization control circuit for a heater for heating water. , Figure 6 is a graph A of the relationship between atmospheric pressure and the saturated vapor temperature (boiling point) of water, Figure 7 is a graph B of the relationship between altitude from sea level and atmospheric pressure, and Figure 8 is a graph of the relationship between altitude and saturated steam of water. A graph C1 showing the relationship with temperature and a graph D showing changes in the set holding temperature of the water heater at each altitude. . In the diagram 1...Hot water storage container 2...Exterior casing 4
...Inner M5...Outer lid 11...Pouring port 20...
・Water heating band heater 22...Main relay
23...Temperature sensor (thermostat) 25...Power outlet 30...Pressure sensitive element 33...Electric contact (micro switch) 30+33...Atmospheric pressure sensor 1...Hot water storage container 4...Inner lid 20...Water heating heater 22...Main relay 23...Temperature sensor 30...Pressure sensing element 33...Electric contact 30+33...Atmospheric pressure sensor Fig. 1 Fig. 3 Fig. 4 Figure 5 Figure 6 Figure 7 Altitude (m)

Claims (1)

[Scope of Claims] 1) A water heater in which a water heating heater and a temperature sensor for controlling electricity supply to the heater to maintain the water temperature at a set temperature are incorporated in the heat retention type hot water storage pot. 1. A water heater, comprising: an atmospheric pressure sensor for sensing an atmospheric pressure corresponding to a boiling point somewhat lower than the boiling point of the water heater, and for stopping energization to the heater based on this sensing signal. 2) The above-mentioned barometric pressure sensor is characterized by comprising a pressure-sensitive element containing a small amount of water in a vacuum container with excellent deformation and recovery properties, and an electric contact that turns on and off in response to the deformation force of the element. A water heater according to claim 1. 3) The water heater according to claims 1 and 2, wherein the atmospheric pressure sensor also functions as the temperature sensor.