CN206311169U - A kind of heat transfer temperature induction type liquid-level switch - Google Patents

Abstract

The utility model provides a heat conduction temperature sensing type liquid level switch, which is characterized in that it includes a heating temperature sensing component, a temperature sensing component, a heating excitation unit, a signal detection processing unit, a power supply module and a housing; The heating temperature sensing component, the temperature sensing component, the heating excitation unit, the signal detection processing unit and the power supply module are all arranged in the housing; line on the housing wall, and the heating temperature sensing component and one end surface of the temperature sensing component are exposed outside the housing wall, the heating excitation unit is electrically connected to the heating temperature sensing component, and the heating temperature sensing The sensing components are respectively electrically connected to the signal detection processing unit; the heating excitation unit and the signal detection processing unit are respectively electrically connected to the power supply module. The utility model has the characteristics of simple structure, small volume, no movable parts, good shock resistance, convenient installation and low cost.

Description

A heat conduction temperature sensing liquid level switch

technical field

The utility model relates to the technical field of liquid level measurement, in particular to a heat conduction temperature induction type liquid level switch.

Background technique

At present, the common types of liquid level switches include float type, photoelectric type, microwave type and other forms. Among them, the float type liquid level switch is widely used, and it is divided into two types: pure mechanical float liquid level switch and magnetic float liquid level switch. The purely mechanical float type liquid level switch uses the float to move up and down with the rise and fall of the liquid level, and generally uses the principle of leverage to open or close the contacts to achieve the purpose of automatic control. However, its structure is complex, its volume is large, its vibration resistance is poor, it is difficult to install, and its cost is high. The magnetic float type liquid level switch uses the magnetic field generated by the float equipped with permanent magnet steel and the magnetic induction element. The magnetic float changes with the rise and fall of the liquid level. The change of the position of the magnetic float causes the change of the electrical parameters of the magnetic induction device to detect the liquid. bit. However, the mechanism of this type of liquid level switch is also relatively complicated, bulky, and inconvenient to install, and the magnetic steel cannot be used under high-temperature medium conditions due to demagnetization at high temperatures. The photoelectric liquid level switch uses the principle of refraction and reflection of light. When the liquid is submerged and not submerged in the liquid level switch, the proportion of refracted light is different, and the emitted light intensity is also different, so as to detect the liquid level. Conical optical prisms are easy to wear and damage, and are prone to false alarms in oil, gas, water vapor and other environments, making their work unreliable. The microwave type is realized by the way of microwave transmission and reception, which is easily affected by reflections such as space obstacles, has strict requirements on the environment, and is relatively expensive.

Contents of the invention

In order to solve the above problems, the purpose of this utility model is to provide a heat conduction temperature-sensing liquid level switch, which has a simple structure, small size, no moving parts, good shock resistance, and high reliability; It can still be used reliably under the environment, easy to install, low in cost, and has low requirements on the environment.

In order to achieve the above purpose, the technical solution adopted by the utility model is: a heat conduction temperature induction liquid level switch, which is characterized in that it includes a heating temperature sensing component, a temperature sensing component, a heating excitation unit, a signal detection processing unit, The power module and the housing; the heating temperature sensing component, the temperature sensing component, the heating excitation unit, the signal detection processing unit and the power module are all arranged in the housing; the heating temperature sensing component, the temperature sensing component The liquid level alarm line at the lower end of the housing is arranged on the housing wall, and the heating temperature sensing component and one end surface of the temperature sensing component are exposed outside the housing wall, and the heating excitation unit is electrically connected to the heating temperature sensing component. At the same time, the heating temperature sensing component and the temperature sensing component are respectively electrically connected to the signal detection processing unit; the heating excitation unit and the signal detection processing unit are respectively electrically connected to the power supply module.

The heating temperature sensing component is composed of a first heat-conducting protective layer, a first heat-conducting layer, a heating element, a second heat-conducting layer, a first temperature sensor and a first heat-insulating layer, and the first heat-insulating layer is A heat-insulating sleeve with an open end, the first heat-conducting protective layer, the first heat-conducting layer, the heating element, the second heat-conducting layer and the first temperature sensor are sequentially and closely attached to the first heat-insulating layer, wherein the first A heat conduction protection layer is located at the opening end of the first heat insulation layer, and the end surface of the first heat conduction protection layer is exposed outside the housing wall.

The temperature sensing component is composed of a second heat-conducting protective layer, a third heat-conducting layer, a second temperature sensor and a second heat-insulating layer, the second heat-insulating layer is a heat-insulating sleeve with an open end, and the The second heat-conducting protective layer, the third heat-conducting layer and the second temperature sensor are sequentially arranged in close contact with the second heat-insulating layer, wherein the second heat-conducting protective layer is located at the opening end of the second heat-insulating layer, and the second heat-conducting layer The end face of the protective layer is exposed outside the housing wall.

The signal detection processing unit includes: a first sensor processing unit, a second sensor processing unit, a temperature comparison processing unit, and an alarm output unit; The component and the temperature sensing component are electrically connected; the output terminals of the first sensor processing unit and the second sensor processing unit are respectively electrically connected with the two input terminals of the temperature comparison processing unit, and the output terminal of the temperature comparison processing unit is connected with the input terminal of the alarm output unit connection; the output end of the alarm output unit is connected with an input/output cable.

The input/output cable is provided with an output interface and an input interface; one end of the input interface is connected to an external power supply, and the other end is electrically connected to the power supply module through the input wire of the input/output cable; one end of the output interface is connected to the controlled The equipment is electrically connected, and the other end is electrically connected to the output terminal of the alarm output unit through the output wire of the input/output cable.

Both the first temperature sensor and the second temperature sensor are thermal resistors, thermocouples, diode temperature sensors or integrated temperature sensors.

The beneficial effects of the utility model:

Both the heating temperature sensing component and the temperature sensing component of the heat conduction temperature sensing liquid level switch provided by the utility model are in contact with the external measured medium, and the heating excitation unit is connected with the heating temperature sensing component, and is excited to make it generate heat. The sensing component and the temperature sensing component exchange heat with their surroundings mainly through the first and second thermal conductive protective layers. When the liquid level switch is not in contact with the liquid medium, the external medium of the liquid level switch is the air gas phase medium. Due to its poor thermal conductivity, the heating temperature sensing component is obviously higher than the ambient temperature, and the temperature sensing component is close to the ambient temperature. The temperature difference is large. When the liquid level switch is in contact with the liquid medium, because the thermal conductivity and heat exchange characteristics of the fluid are significantly higher than those of the gaseous medium such as air, the temperature of the heating temperature sensing component and the temperature sensing component are quickly balanced with the medium temperature, and both are close to the medium temperature , making the temperature difference between the two components smaller. By judging the temperature difference between the two components, it is judged whether the liquid level is alarming. The heating temperature sensing component and the temperature sensing component are respectively electrically connected to the signal detection processing unit to complete signal detection, processing and alarm.

The heat conduction temperature sensing type liquid level switch provided by the utility model has small volume, no movable parts, good shock resistance, can be conveniently installed on the tank wall or the top of the liquid container, and has high reliability. And it can still be used reliably in high and low temperature media.

The utility model will be described in detail below in conjunction with the accompanying drawings and embodiments, so that the advantages and features of the utility model can be more easily understood by those skilled in the art, but not as a limitation of the utility model.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a schematic diagram of a heating temperature sensing assembly of the present invention;

Fig. 3 is a schematic diagram of a temperature sensing assembly of the present invention;

In the figure, 1. Heating temperature sensing component; 2. Temperature sensing component; 3. Heating excitation unit; 4. Signal detection processing unit; 5. First sensor processing unit; 6. Second sensor processing unit; 7. Temperature Comparison processing unit; 8. Alarm output unit; 9. First heat conduction protective layer; 10. First heat conduction layer; 11. Heating element; 12. Second heat conduction layer; 13. First temperature sensor; 14. First heat insulation layer; 15. second heat conduction protective layer; 16. third heat conduction layer; 17. second temperature sensor; 18. second heat insulation layer; 19. shell; 20. input/output cable; 21. output interface; 22 , input interface; 23, power module; 24, liquid level alarm line.

detailed description

Example 1

A heat conduction temperature sensing liquid level switch includes a heating temperature sensing component 1, a temperature sensing component 2, a heating excitation unit 3, a signal detection processing unit 4, a power module 23 and a housing 19; the heating temperature sensing component 1. The temperature sensing component 2, the heating excitation unit 3, the signal detection processing unit 4 and the power module 23 are all arranged in the casing 19; the heating temperature sensing component 1 and the temperature sensing component 2 are arranged in the casing 19 The liquid level alarm line 24 at the lower end is on the shell wall, and one end surface of the heating temperature sensing component 1 and the temperature sensing component 2 are exposed outside the shell wall, and the heating excitation unit 3 is electrically connected with the heating temperature sensing component 1 At the same time, the heating temperature sensing component 1 and the temperature sensing component 2 are electrically connected to the signal detection processing unit 4 respectively; the heating excitation unit 3 and the signal detection processing unit 4 are respectively electrically connected to the power module 23 .

Example 2

As shown in Figure 1, a heat conduction temperature sensing liquid level switch includes a heating temperature sensing component 1, a temperature sensing component 2, a heating excitation unit 3, a signal detection processing unit 4, a power module 23 and a housing 19; The heating temperature sensing component 1, the temperature sensing component 2, the heating excitation unit 3, the signal detection processing unit 4 and the power supply module 23 are all arranged in the casing 19; the heating temperature sensing component 1, the temperature sensing component 2 Set the liquid level alarm line 24 at the lower end of the housing 19 on the housing wall so that it is in direct contact with the external measured medium, and one end surface of the heating temperature sensing component 1 and the temperature sensing component 2 are exposed on the housing Outside the wall, the heating excitation unit 3 is electrically connected to the heating temperature sensing assembly 1, while the heating temperature sensing assembly 1 and the temperature sensing assembly 2 are electrically connected to the signal detection processing unit 4 respectively; the heating excitation unit 3 and the signal detection processing unit 4 They are electrically connected to the power module 23 respectively.

As shown in Figure 2, the heating temperature sensing assembly 1 is composed of a first heat conducting protective layer 9, a first heat conducting layer 10, a heating element 11, a second heat conducting layer 12, a first temperature sensor 13 and a first heat insulating layer 14, the first heat insulation layer is a heat insulation sleeve with one end open, the first heat conduction protection layer 9, the first heat conduction layer 10, the heating element 11, the second heat conduction layer 12 and the first temperature sensor 13 are sequentially and tightly fitted in the first heat insulation layer 14, wherein the first heat conduction protection layer 9 is located at the opening end of the first heat insulation layer 14, and the end surface of the first heat conduction protection layer 9 is exposed outside the housing wall.

As shown in Figure 3, the temperature sensing assembly 2 is composed of a second heat conduction protection layer 15, a third heat conduction layer 16, a second temperature sensor 17 and a second heat insulation layer 18, and the second heat insulation layer The layer 18 is a heat insulation sleeve with one end open, and the second heat conduction protection layer 15, the third heat conduction layer 16 and the second temperature sensor 17 are arranged in the second heat insulation layer 18 sequentially and tightly, wherein the second The heat conduction protection layer 15 is located at the opening end of the second heat insulation layer 18 , and the end surface of the second heat conduction protection layer 15 is exposed outside the housing wall.

As shown in Figure 1, the described signal detection processing unit 4 includes: a first sensor processing unit 5, a second sensor processing unit 6, a temperature comparison processing unit 7 and an alarm output unit 8; the first sensor processing unit 5, the second The input end of the sensor processing unit 6 is electrically connected with the heating temperature sensing assembly 1 and the temperature sensing assembly 2 respectively; the output ends of the first sensor processing unit 5 and the second sensor processing unit 6 are respectively connected to two The input end is electrically connected, and the output end of the temperature comparison processing unit 7 is connected to the input end of the alarm output unit 8; the output end of the alarm output unit 8 is connected to an input/output cable 20.

The input/output cable 20 is provided with an output interface 21 and an input interface 22; one end of the input interface 22 is connected to an external power supply, and the other end is electrically connected to the power supply module 23 through the input wire of the input/output cable 20; the described One end of the output interface 21 is electrically connected to the controlled device, and the other end is electrically connected to the output end of the alarm output unit 8 through the output wire of the input/output cable 20 .

The first heat-conducting protective layer 9 and the second heat-conducting protective layer 15 have the same characteristics, and the ability to exchange heat with the outside is close.

The heat conduction temperature sensing type liquid level switch of the utility model is to judge whether the liquid level alarms by processing the temperature difference between the heating temperature sensing component 1 and the temperature sensing component 2 through the temperature comparison processing unit 7 .

The heating temperature sensing component 1 and the temperature sensing component 2 are installed at the liquid level alarm limit. The volume of the two components is relatively small during production, and the surface area of the heat conduction protective layer is also small, which is convenient for rapid heat balance. The two components are installed at the position where the liquid level switch needs to be detected, and the first and second heat conduction protection layers are exposed on the surface of the liquid level switch and directly contact with the measured medium. The temperature sensing component transmits heat through the second heat-conducting protective layer, and the temperature of the second temperature sensor is the same as the temperature of the surrounding medium (such as air or liquid); the heating element of the heating temperature sensing component adopts an electric heating device, which is realized by resistance in this example. The resistance generates heat when it is energized, and it generates heat under the action of the heating excitation source unit. The heating excitation source unit 3 can be a voltage source or a current source. The heat generated by the heating element 11 is transmitted to the first temperature sensor 13 and the first heat-conducting protective layer 9 at the same time. After the temperature is balanced, the temperature of the first temperature sensor 13 is air when the surrounding medium is not reached. When the alarm is not reached, it is higher than the air temperature. Higher than the temperature of the second temperature sensor 17; when contacting the liquid medium reaches the alarm, due to the difference in thermal conductivity and heat exchange performance of the air and liquid medium, the temperature of the first temperature sensor 13 and the second temperature sensor 17 is close, so that it can Accurately determine whether the liquid level alarm. The signal detection processing unit 4 mainly amplifies, converts, detects, and compares the electrical signals of the front-end temperature sensor, so as to achieve the purpose of alarm judgment and output.

In this embodiment, the first and second thermally conductive protective layers are metal bodies, and the first, second, and third thermally conductive layers are all thermally conductive adhesives. The first and second thermally conductive protective layers transfer heat through thermally conductive adhesives and heating elements. To meet the requirements of more liquid media, but not limited to this, it is also possible to directly use a thermal conductive adhesive with a certain protective function without the thermal conductive protective layer of the metal body to meet the low-cost requirements suitable for specific liquid media.

In this example, the first heat insulation layer and the second heat insulation layer are to prevent heat exchange between the heating temperature sensing component 1 and the temperature sensing component 2 and the outside except the heat conduction protection layer, if the housing itself has a better If there is no heat resistance effect, the heat insulation layer does not need to be specially set, and the shell or air gap can also perform its function.

In this embodiment, the first and second temperature sensors use thermal resistance sensors to sense temperature changes, and are electrically connected to the first sensor processing unit and the second sensor processing unit as processing circuits for thermal resistance signals; when the first and second When the second temperature sensor adopts a thermocouple sensor, its corresponding first sensor processing unit and second sensor processing unit are then changed to a thermocouple processing circuit; when the first and second temperature sensors adopt an integrated sensor or a digital temperature sensor , the first sensor processing unit and the second sensor processing unit are not needed, and the temperature output can be directly processed by the temperature comparison processing unit 7 .

The temperature comparison processing unit 7 is a processing circuit or a processor with this function that performs difference and comparison operations on the output signals of the first and second sensor processing units corresponding to the temperatures of the first and second temperature sensors.

The alarm output unit 8 is an alarm output device or signal output by sound, light and electricity.

The processing circuit of the thermal resistance and the processing circuit of the thermocouple are both prior art, and will not be described in detail here.

The heat conduction temperature sensing type liquid level switch provided by the utility model has small volume, no movable parts, good shock resistance, can be conveniently installed on the tank wall or the top of the liquid container, and has high reliability. And it can still be used reliably in high and low temperature media.

Of course, the above description is not a limitation to the present utility model, and the present utility model is not limited to the above-mentioned examples, and changes, modifications, additions or replacements made by those skilled in the art within the essential scope of the present utility model are also acceptable. Belong to the protection scope of the utility model.

The unexplained parts involved in the utility model are the same as the prior art or are implemented by using the prior art, so they will not be described one by one here.

Claims (5)

1. A heat conduction temperature sensing liquid level switch, characterized in that it includes a heating temperature sensing component (1), a temperature sensing component (2), a heating excitation unit (3), a signal detection processing unit (4), Power module (23) and housing (19); said heating temperature sensing component (1), temperature sensing component (2), heating excitation unit (3), signal detection processing unit (4) and power module ( 23) are all arranged in the casing (19); the heating temperature sensing assembly (1) and the temperature sensing assembly (2) are arranged at the liquid level alarm line (24) at the lower end of the casing (19). wall, and one end surface of the heating temperature sensing component (1) and the temperature sensing component (2) are exposed outside the housing wall, the heating excitation unit (3) is electrically connected with the heating temperature sensing component (1), and at the same time The heating temperature sensing component (1) and the temperature sensing component (2) are respectively electrically connected to the signal detection processing unit (4); the heating excitation unit (3) and the signal detection processing unit (4) are respectively electrically connected to the power supply module (23) connect. 2. A heat-conducting temperature-sensing liquid level switch according to claim 1, characterized in that: the heating temperature sensing component (1) is composed of the first heat-conducting protective layer (9), the first heat-conducting layer ( 10), heating element (11), second heat conduction layer (12), first temperature sensor (13) and first heat insulation layer (14), the first heat insulation layer is a heat insulation sleeve with one end open , the first heat-conducting protective layer (9), the first heat-conducting layer (10), the heating element (11), the second heat-conducting layer (12) and the first temperature sensor (13) are sequentially arranged in close contact with each other. In a heat insulation layer (14), the first heat conduction protection layer (9) is located at the opening end of the first heat insulation layer (14), and the end face of the first heat conduction protection layer (9) is exposed outside the housing wall. 3. A heat-conducting temperature-sensing liquid level switch according to claim 1, characterized in that: the temperature sensing component (2) is composed of the second heat-conducting protective layer (15), the third heat-conducting layer (16 ) and the second temperature sensor (17) and the second heat insulation layer (18), the second heat insulation layer (18) is a heat insulation sleeve with one end open, the second heat conduction protection layer (15) , the third heat conduction layer (16) and the second temperature sensor (17) are arranged in close contact with each other in the second heat insulation layer (18), wherein the second heat conduction protection layer (15) is located in the second heat insulation layer ( 18), and the end face of the second heat-conducting protective layer (15) is exposed outside the housing wall. 4. A heat conduction temperature-sensing liquid level switch according to claim 1, characterized in that: the signal detection processing unit (4) includes: a first sensor processing unit (5), a second sensor processing unit ( 6), the temperature comparison processing unit (7) and the alarm output unit (8); the input terminals of the first sensor processing unit (5) and the second sensor processing unit (6) are respectively connected with the heating temperature sensing component (1), temperature The sensing component (2) is electrically connected; the output ends of the first sensor processing unit (5) and the second sensor processing unit (6) are respectively electrically connected to the two input ends of the temperature comparison processing unit (7), and the temperature comparison processing unit (7) The output end is connected to the input end of the alarm output unit (8); the output end of the alarm output unit (8) is connected to an input/output cable (20). 5. A heat conduction temperature-sensing liquid level switch according to claim 4, characterized in that: said input/output cable (20) is provided with an output interface (21) and an input interface (22); said One end of the input interface (22) is connected to an external power supply, and the other end is electrically connected to the power module (23) through the input wire of the input/output cable (20); one end of the output interface (21) is electrically connected to the controlled device, and the other end The output wire of the input/output cable (20) is electrically connected to the output terminal of the alarm output unit (8).