JPH04248452A - Method and device for detecting ice - Google Patents

Abstract

PURPOSE: To obtain a new ice detection method which can solve the problems in a electrode rod method or a float switch method. CONSTITUTION: From an oscillating part 7A of a detector 7 actuated by an oscillator 1, a signal of a specific frequency is generated in a specific isolation room capable of freezing water. This frequency signal is received with a receiving part 7B, and the received signal is detected with voltage doubling detection diodes 9 and 10, amplified with an amplifier 11, and compared with a reference voltage with a comparator 19. If a freezing state of water is detected from the comparison result, alarms of a light-emitting diode 28 and a buzzer 29 are generated.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to boilers, refrigerators, or automobiles, and particularly relates to an ice detection method and apparatus for detecting freezing of water and freezing of moisture in the air. .

0002

[Prior Art] For example, in the case of a boiler that uses heat from a burner to circulate water through piping for heating and heat exchange with hot water, if there is no water in the piping due to a water outage or other causes, the heat exchange of the boiler will be interrupted. Not only does boiler damage due to overheating of the boiler and the associated risk of fire occur, but if the water inside the boiler pipes freezes, the circulation pump will not be able to circulate the water and the boiler will be destroyed. A case had occurred. Furthermore, in the case of automobiles, the radiator is filled with water to cool the engine, and antifreeze is added to prevent damage to the radiator, but in extremely cold temperatures, even if antifreeze is added, the water in the radiator may freeze. Because of this, the radiator had a tendency to be damaged. In order to prevent this phenomenon, conventional methods have been to install electrode rods that use electric current at the relevant location to detect the freezing state of the water, or to install a float switch that uses a permanent magnet in the hot water tank. It was used to detect freezing conditions.

0003

[Problems to be Solved by the Invention] However, since the electrode rod method uses alternating current or direct current, it has the problem of malfunction due to electrolysis, scale, and water turbidity, and the float switch method uses alternating current or direct current. Since it receives heat, there is a problem in that the temperature change is severe and the internal permanent magnet is thermally deformed and its performance is degraded.

[0004] Furthermore, in the case of conventional refrigerators, there was no means to detect the presence or absence of ice, so a method was adopted to remove ice and frost from the heat exchanger using a timer that operates based on time and temperature. However, this has the problem of wasting unnecessary power.

[0005]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an ice detection method and apparatus that overcomes the conventional problems caused by electrolysis, scale, turbidity, and direct boiler heat. According to one aspect of the present invention to achieve these objects, an ice detection method is provided, which includes generating a predetermined frequency signal inside the piping of a boiler, and causing the inside of the piping to be detected by the frequency signal. This system consists of several steps: detecting the state of the water present, determining whether the detected state of the water is freezing, and issuing an alarm when the above-mentioned freezing state occurs.

According to yet another feature of the invention, an ice sensing device is provided. This device includes a frequency oscillation means for providing a predetermined frequency signal inside the piping of the boiler, a detection means installed inside the piping and operated by the frequency signal to detect the state of water existing inside the piping, Consisting of a discriminating means for detecting and amplifying the signal detected by the detecting means to determine whether the water is frozen, and an alarm means operated by the discriminating means to warn the outside of the frozen state of the water. It is what was done.

[0007]

[Operation] According to the present invention, by focusing on the difference in electromagnetic wave transmission ratio (relative dielectric constant) between water, ice, or air, a predetermined frequency signal is generated inside a predetermined compartment where water can freeze, and the water The state of the water present inside the compartment is detected based on the reception state of the frequency signal received through a medium such as ice or air. In other words, since the dielectric constant decreases in the order of water, ice, and air, it is possible to detect the condition of the dielectric medium between the transmitting part and the receiving part (whether it is frozen or not) from the receiving state of the transmitted frequency signal. I have to.

The frequency oscillation signal according to the present invention is preferably a rectangular wave or a sine wave.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 illustrates a circuit diagram of an ice detection device according to the present invention, and is designated by reference number 1.
1 illustrates a frequency oscillator for generating a rectangular wave. The on-time period of the rectangular wave output from oscillator 1 (FIG. 2A) is determined by resistor 2 and capacitor 3, and the off-time period is determined by resistors 4 and 2 and capacitor 3.
Determined by The rectangular wave signal outputted from the oscillator 1 is applied through the coupling capacitor 5 to the transmitting section 7A of the detector 7 installed inside the piping 6 shown in FIG.

The mounting state of the detector 7 shown in FIG. 3 is for application to a boiler. However, this can be applied not only to the boiler but also to the radiator of an automobile or the freezer compartment of a refrigerator (not shown). A rectangular wave frequency signal emitted from the transmitter 7A of the detector 7 is sensed by the receiver 7B, passed through the coupling capacitor 8, voltage-doubled by diodes 9 and 10, and applied to the non-inverting terminal of the amplifier 11. Here, the resistor 12 and capacitor 13 represent a noise removal filter.

The amplifier 11 amplifies the input signal using amplifying resistors 14 to 17 and applies the amplified signal to the inverting terminal of a comparator 19 through a resistor 18.
It compares the reference voltage set by and its inverted input voltage and outputs a high or low state signal. If the water present in the pipe 6 does not freeze, the output of the comparator 19 is configured to maintain a low state.

A bias resistor 2 is connected to the output terminal of the comparator 19.
4 and 25 to the base of the transistor 26. When the transistor 26 is turned on (when the water is frozen), the relay 27 is activated and the light emitting diode 28 and the buzzer 29 can be activated at the same time. The operation of the first embodiment of the present invention configured as described above will be explained in detail. The installation example shown in FIG. 3 is based on the assumption that the boiler piping is installed adjacent to the building wall 30 because most of the ice forms in the piping adjacent to the building wall 30 during the winter season. However, such installation locations are not limited to boilers, but may also be automobile radiators.

When the power supply +Vcc is applied with the detector 7 installed inside the boiler piping 6, the oscillator 1 generates a voltage of approximately 10KHz to 200K due to the resistors 2, 4 and the capacitor 3.
A rectangular wave frequency signal of Hz (see FIG. 2A) is generated and applied to the transmitter 7A of the detector 7. At this time, the transmitter 7A emits a rectangular wave frequency signal into the pipe 6. If the water inside the pipe 6 does not freeze, the receiving section 7B of the detector 7 will receive almost all of the rectangular wave frequency signal emitted from the transmitting section 7A.

The rectangular wave frequency signal thus received with almost no loss is subjected to voltage doubler detection by diodes 9 and 10 as shown in FIG. 2B, and then noise is removed by resistor 12 and capacitor 13. The detected signal of FIG. 2B is input to the amplifier 11 and amplified. The input signal at this time is applied to the inverting terminal of the comparator 19. Comparator 19 compares the input signal and the reference voltage signal and outputs a low state signal.

When the output of comparator 19 is low, transistor 26 is turned off and relay coil 27A is turned off.
Current no longer flows, and accordingly, the light emitting diode 28 and buzzer 29 do not generate an alarm sound. Therefore, if the alarm is not generated, the user can easily know that the water present inside the boiler piping has not frozen.

On the other hand, if the water existing inside the pipe 6 is frozen, the rectangular wave frequency signal emitted from the transmitting section 7A cannot pass through the ice, so that the receiving section 7B does not detect the received signal. Therefore, since there is no signal applied to the inverting input terminal of comparator 19, the output of comparator 19 remains high. The output signal of comparator 19 turns on transistor 26 via bias resistor 24. When the transistor 26 is turned on, current flows through the relay coil 27A to generate electromagnetic force, which turns on the relay contact 27B and causes the light emitting diode 28 and buzzer 29 to generate an alarm. Therefore, the user can use the light emitting diode 28
The occurrence of an abnormal condition inside the pipe 6 can be easily recognized by the visual alarm caused by the alarm and the audible alarm caused by the buzzer 29.

[0017] Furthermore, if there is no water inside the pipe 6,
The strength of the rectangular wave frequency signal radiated from the transmitting section 7A becomes extremely weak, and the signal cannot reach the receiving section 7B. In this case, an alarm is generated by the light emitting diode 28 and the buzzer 29 as in the case where the water freezes. As described above, the first embodiment uses the square wave frequency to quickly alert the user that the water inside the pipe 6 has frozen or that there is no water inside the pipe 6. It has the feature of being able to prevent damage in advance.

FIG. 4 shows another embodiment of the present invention.
This example uses a sine wave frequency, and is shown in FIG.
The same reference numbers as in Figure 1 represent the same parts. Figure 4 shows Zener diode 40, 41 and operational amplifier 42,
43 and a large number of capacitors 44 to 46 and resistors 47 to 50
This is a device for detecting the freezing state of water using a sine wave frequency of 50 to 1200 Hz as shown in Figure 2C, and in this case, it is specifically for detecting the presence of ice or frost in a refrigerator. It is.

To explain the circuit of FIG. 4, it is assumed that the detector 7 is installed on the side wall (not shown) of the freezer compartment of the refrigerator. That is, it is assumed that the boiler piping 6 in FIG. 3 is placed in the freezer compartment of the refrigerator. Therefore, FIG. 4 is for detecting ice or frost formed on the side wall of the freezer compartment of a refrigerator. First of all,
If no ice or frost is formed inside the freezer compartment, the 50-1200 Hz sine wave frequency signal (FIG. 2C) emitted from the transmitter 7A is not transmitted to the receiver 7B. This is because the electromagnetic wave transmission ratio of ice and air is different, and the transmitter 7A
This is because the electric field strength of the sinusoidal frequency radiated from the air is not sufficient to pass through the air. Therefore, the amplifier 11 is not activated and the comparator 19 outputs a low signal to be applied to the base of the transistor 26. At this time, the transistor 26 is turned off and the relay 27 does not operate, so that the light emitting diode 28 and the buzzer 29 cannot generate an alarm sound.

However, when ice or frost forms on the side wall of the freezer compartment of the refrigerator, the peak value of the sine wave frequency signal shown in FIG. 2C is about 10V, and a signal of this level can pass through the ice. That is, when the side wall of the freezer compartment is frozen or frosted, the sine wave frequency signal emitted from the transmitter 7A passes through the ice or frost and is transmitted to the receiver 7B. At this time, the receiving section 7B detects the sine wave frequency signal and connects the diodes 9 and 10.
However, the diodes 9 and 10 perform voltage double detection on the input signal as shown in FIG. 2C and apply it to the amplifier 11.

Amplifier 11 amplifies the input signal and applies it to comparator 19. Comparator 19 compares the input signal with a reference voltage signal and outputs a high-state signal to transistor 2.
6. At this time, the transistor 26 is turned on, current flows through the relay coil 27A, and electromagnetic force is generated. Therefore, the relay contact 27B is turned on and an alarm is generated by the light emitting diode 28 and the buzzer 29. What is important here is that since a certain degree of frost may form in the freezer compartment of the refrigerator, it is preferable to adjust the values of the reference voltage setting resistors 20 to 23 of the comparator 19 so that a slight degree of frost can be tolerated.

Although the invention has been described with respect to specific embodiments relating to boilers and refrigerators, the invention is not limited thereto, and may be modified and modified in many ways without departing from the scope of the appended claims. be.

[0023]

[Effects of the Invention] As explained above, the present invention transmits a rectangular wave or sine wave frequency signal, and detects whether or not the medium is frozen based on the receiving state. It has the feature of being able to eliminate the problems of the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an ice detection device according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram of a frequency oscillation signal used in the present invention.

FIG. 3 is a diagram illustrating an installation state of an ice detector used in the present invention.

FIG. 4 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

1...Square wave generator 7...Detector 7A...Transmission section 7B...Receiving section 9, 10... Voltage doubler detection diode 11...Amplifier 19...Comparator 27...Relay 28...Light emitting diode 29...Buzzer

Claims (9)

[Claims] Claim 1: A method for detecting the freezing state of water, wherein a frequency signal of a predetermined form is generated inside a predetermined compartment in which water can be frozen, and the reception state of the frequency signal determines the presence of water inside the compartment. 1. An ice detection method comprising the steps of: detecting the state of water, determining whether the detected water state is a freezing state, and issuing a warning when the above-mentioned freezing state occurs. 2. The ice detection method according to claim 1, wherein the frequency signal is a rectangular wave frequency signal. 3. The ice detection method according to claim 1, wherein the frequency signal is a sine wave signal. 4. An apparatus for detecting freezing of water, comprising: a frequency oscillation means for providing a frequency signal of a predetermined form inside a predetermined compartment in which water or moisture can freeze; A detection means is installed and operated by the frequency signal to detect the state of water or moisture present inside the compartment, and a signal detected by the detection means is detected and amplified to determine the frozen state of the water. 1. An ice detection device comprising: a discriminating means for detecting water; and an alarm means operated by the discriminating means for warning the outside of the frozen state of water. 5. An ice detection device according to claim 4, wherein said frequency oscillation means is a rectangular wave frequency generator. 6. An ice detection device according to claim 4, wherein said frequency oscillation means is a sine wave frequency generator. 7. The ice detection device according to claim 4, wherein the detection means is installed within piping of a boiler. 8. An ice detection device according to claim 4, wherein said detection means is installed in a freezing compartment of a refrigerator. 9. An ice detection device according to claim 4, wherein said detection means is installed in a radiator of an automobile.