CN201096545Y - Solar water heater temperature- liquid level sensor - Google Patents

Abstract

The utility model relates to a liquid-level temperature sensor of a solar energy water heater. A sensing element is composed of a group of liquid-level electrodes constructed by more than three conducting wires made of stainless steel and a temperature probe connected by two different types of metal conducting wires; the liquid-level electrodes comprise an electrode and a public electrode; the sensing element is separated from the pipelines of the electric apparatus. The liquid-level temperature sensor has the advantages that the whole senor is not needed to be sealed because the electronic element is not contacted with water; the liquid-level temperature sensor has simple structure, convenient mounting, uneasy scaling of the electrodes and long service life.

Description

Solar water heater temperature liquid level sensor

technical field

The utility model relates to a sensor, in particular to a sensor specially designed for a solar water heater and capable of sensing liquid level and temperature.

Background technique

The existing technology is used in the liquid level and temperature sensors of solar water heaters. The main problem is that the electronic components are integrated with the sensor probe and directly enter the water tank, so that the electronic components are in the high-temperature water environment for a long time, which accelerates the aging of the electronic components and reduces the service life. The 2nd, must have good sealing performance in order not to make electronic component contact with water, and existing sealing method is mainly useful heat-shrinkable tubing, silica gel, epoxy resin etc., and adopts above-mentioned method service life all not long; The 3rd is The prior art generally uses a thermistor, and the thermistor is easily damaged in a high-temperature, high-humidity environment for a long time.

Contents of the invention

The utility model mainly solves the shortcomings of the prior art, thereby developing a solar water heater liquid level temperature sensor with simple structure, reliability, electromechanical separation and long service life.

Another object of the utility model is to provide a liquid level temperature sensor for solar water heaters whose electrodes are not easily scaled.

The above-mentioned technical problems of the utility model are mainly solved by the following technical solutions: a temperature and liquid level sensor for a solar water heater, which has a sensing element and an electrical circuit, and is characterized in that: the sensing element is installed on the body A group of more than three liquid level electrodes using stainless steel wires and a temperature probe connected by two different metal wires; the liquid level electrodes include electrodes and common electrodes; the sensing element is separated from the electrical circuit . The diameter of the stainless steel wire can be determined as required.

The above-mentioned technical scheme can adopt two kinds of solutions according to the different structures of the air outlet of the solar water heater hot water tank:

One is that the air outlet of the hot water tank is located at the top, and a vertical plug-in sensor is used. The electrodes of its liquid level electrode are a group of exposed but separated stainless steel wires of different lengths, and the common electrode is a copper tube. , generally using a copper tube; the metal wire of the temperature probe is covered by an insulating material, placed in the copper tube of the common electrode, and the lower end of the copper tube is closed. The thickness of the electrodes is based on the principle that the rods can be separated from each other, or a separation frame can be used to prevent contact between the electrodes and reduce the diameter of the electrodes.

In order to make the gas outlet of the hot water tank go out smoothly, there are T-shaped through holes for gas outlet in the body, and the through holes lead to both sides from the bottom of the body. Guide the air from the middle to the two sides.

The other is that the gas outlet of the hot water tank is located on the side, and a horizontal plug-in sensor is used. The liquid level electrode is a set of stainless steel wires of different lengths. The wires are covered by insulating materials, and the ends of the wires are exposed; the metal wires of the temperature probe Covered by insulating material. In this case there is no problem of mutual contact between the wires, so that the wire diameter can be relatively small. Material can be greatly saved.

As a preferred solution, a helical coil is wound on the exposed wire end. This is conducive to accurate measurement of the water level.

As a preferred solution, the end of the metal wire of the temperature probe is connected with a weight body. A weight body is connected to the lower end of the temperature probe so that the wire is always in a vertical state, so that the water level measurement is more accurate.

The technical scheme of the utility model is based on:

Water level electrode: When the electrode is put into the water tank, according to the principle of water conduction, when the water level in the water tank changes, the resistance value at the two ends of the water level signal line connected to it will also change synchronously, and the different resistance values can be obtained through the conversion of the instrument. Get a certain water level value.

Temperature sensor: It is based on the thermal characteristics of two different materials. Two metal wires of different materials, when the temperature changes, an electromotive force will be generated at the two ends of the temperature signal line. After the electromotive force is amplified by the differential amplifier in the instrument, it is sent to the single-chip microcomputer for linearization processing through A/D conversion, because There is also a certain relationship between this electromotive force and the ambient temperature, so the resistance value of the thermistor in the casing must be detected to determine the ambient temperature. The temperature of the hot water in the water tank is obtained after comprehensive calculation of the ambient temperature and the electromotive force.

The principle of preventing electrode fouling is that when measuring the liquid level, one end of the liquid level signal line is positive and the other end is negative, and when measuring the ambient temperature, the positive and negative poles are opposite, so the polarity of the potential on the electrode changes, is High-frequency AC pulse, so it is not easy to scale on the upper electrode.

Therefore, the beneficial effects of the utility model are: since the electronic components do not touch water, the whole sensor does not need to be sealed, the structure is simple, the installation is convenient, the electrodes are not easy to scale, and the service life is long.

Description of drawings

Accompanying drawing 1 is a kind of structural representation of the utility model;

Accompanying drawing 2 is another kind of structural representation of the utility model.

Accompanying drawing 3 is the electrical schematic diagram of the utility model.

Detailed ways

The technical solution of the utility model is further specifically described below through the embodiments and in conjunction with the accompanying drawings.

Example:

As shown in Figure 1, it is a vertical plug-in sensor used on the top of a hot water tank. In this embodiment, there are four electrodes of the liquid level electrode, namely 11, 12, 13, and 14, which are a group of exposed but separated from each other and of different lengths. The common electrode 10 is a copper tube, generally using a copper tube; the metal wire of the temperature probe 2 is covered by an insulating material, placed in the copper tube of the common electrode, and the lower end of the copper tube is closed. The thickness of the electrodes is based on the principle that the rods can be separated from each other, or a separation frame can be used to prevent contact between the electrodes and reduce the diameter of the electrodes. In order to make the air outlet of the hot water tank go out smoothly, there is a T-shaped through hole 31 for air outlet in the body 3. The through hole leads from the bottom of the body to both sides, and guides from the middle to the air outlet 32 on the two sides, as shown in the figure Among them, the liquid level electrode is connected to the metal wire of the temperature probe 2 with the signal line 1, and the 5 is a circuit board.

As shown in Figure 2, the air outlet of the hot water tank is located on the side, and a horizontal plug-in sensor is used. There are four liquid level electrodes 11, 12, 13, and 14, and 10 is a common electrode, which is a group of stainless steel with different lengths. The above-mentioned wires are covered by insulating materials, the ends of the wires are exposed, and the exposed ends of the wires are wound with helical coils, and the metal wires of the temperature probe 2 are covered by insulating materials. In this case, there is no problem of mutual contact between the wires, so the diameter of the wires can be relatively thin, and the material used can be greatly saved. A weight body 4 is connected to the end of the metal wire of the temperature probe, so that the wire is always in a vertical state, and the water level measurement is more accurate. In the figure, the signal line 1 is used to connect the liquid level electrode with the metal wire of the temperature probe 2, and 4 is Fastener.

In the electrical schematic diagram shown in Figure 3, 11, 12, 13, 14, and 10 are electrodes, among which 10 is a common electrode, T is a temperature sensor, D ₁ and D ₂ are triodes, R ₁ , R ₂ , R ₃ , _R4 is the resistor, R _T thermistor.

Water level measurement:

① When there is no water, the resistance value R of terminals T ₃ and T _{4 is no water} = R ₁ +R ₂ +R ₃ +R ₄

② When the water level is at level 1, that is, electrodes 10 and 11 are short-circuited, the resistance value R _{level 1} = R ₂ + R ₃ + R ₄

③When the water level is at the second level, that is, the 10th electrode is short-circuited with the 11th and 12th electrodes, and the resistance value _{R2 level} = _R3 + _R4

④ When the water level is at the third level, that is, the 10th electrode is short-circuited with the 11th, 12th, and 13th electrodes, and its resistance value is _R3 = _R4

⑤ At the 4th water level, that is, the 10th electrode is short-circuited with the 11th, 12th, 13th, and 14th electrodes.

Its resistance value R _{4 files} = 0Ω

Measuring the water level is to measure the resistance of _T3 and _T4 terminals.

Temperature measurement:

①The temperature sensor T will generate a corresponding potential difference at the T ₁ and T ₂ terminals according to the temperature change, and the potential value and the temperature value are in a corresponding relationship.

②The potential difference between the two ends of T ₁ and T ₂ is amplified by the instrument amplifier, converted by A/D, and then sent to the single-chip microcomputer to be converted into a temperature value and displayed.

Claims (6)

1. A temperature and liquid level sensor for a solar water heater, which has a body, a liquid level sensor, a temperature sensor and matching electrical components and electrical circuits, and is characterized in that: the liquid level sensor is a group of three or more installed on the body A liquid level electrode using a stainless steel wire, the temperature sensor is a temperature probe connected by two different metal wires; the liquid level electrode includes an electrode and a common electrode; the sensor and electrical components and electrical circuits phase separation. 2. The solar water heater temperature liquid level sensor according to claim 1, characterized in that: the electrodes of the liquid level electrodes are a group of bare but separated stainless steel wires of different lengths, and the common electrodes are a A copper tube; the metal wire of the temperature probe is covered by insulating material, placed in the copper tube of the common electrode, and the lower end of the copper tube is closed. 3. The temperature and liquid level sensor for solar water heater according to claim 1 or 2, characterized in that: there is a T-shaped through hole for air outlet in the body, and the through hole leads from the bottom of the body to both sides. 4. The solar water heater temperature liquid level sensor according to claim 1, characterized in that: said liquid level electrode is a group of stainless steel wires of different lengths, said wires are covered by insulating material, and the ends of the wires are exposed; The metal wires of the temperature probe are covered with insulating material. 5. The solar water heater temperature and liquid level sensor according to claim 4, characterized in that: said exposed wire end is wound with a helical coil. 6. The temperature and liquid level sensor for solar water heater according to claim 4 or 5, characterized in that: the end of the metal wire of the temperature probe is connected with a weight body.

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