Digital liquid temperature transmitter

Abstract

The utility model relates to heating and water temperature detection technical field especially relates to a digital liquid temperature transmitter, include: blind pipe for inserting to the liquid pipeline of heating equipment, digital temperature sensor, digital temperature sensor sets up in blind pipe inside, digital signal processor is located the outside of blind pipe, wherein, the one end of blind pipe insertion in the liquid pipeline of heating equipment is equipped as the closed end, and the inner chamber sealing of blind pipe fills with heat conduction medium, digital temperature sensor is embedded in heat conduction medium and is connected to digital signal processor through wire outward, to the digital signal transmission of digital signal processor and exports temperature data through digital signal processor. The utility model relates to a digital liquid temperature transmitter can help to avoid the temperature detection signal transmission distortion of heating equipment liquid pipeline, improve measurement accuracy.

Description

Technical Field

[0001] This utility model relates to the field of HVAC water temperature detection technology, and in particular to a digital liquid temperature transmitter. Background Technology

[0002] In the fields of HVAC, building automation, and industrial fluid process control, accurate monitoring of liquid temperature within pipelines is a crucial step in achieving automated system control and energy-efficient operation. Currently, the common technical means to achieve this function is to use temperature transmitters or temperature sensors for temperature measurement.

[0003] In existing technologies, mainstream pipeline liquid temperature measurement schemes typically rely on analog sensing elements, such as negative temperature coefficient (NTC) thermistors, PT100 / PT1000 platinum resistance thermometers, or various thermocouples. Their working principle is as follows: these temperature-sensitive sensing element probes are placed inside the pipe or attached to the outer wall of the pipe. When the temperature of the measured liquid changes, the resistance value of the sensing element itself or the electromotive force it generates will change accordingly in a predictable manner. However, the outputs of these sensing elements are all weak analog electrical signals (voltage, current, or resistance signals). In order to be recognized and processed by the downstream controller or data acquisition unit (such as PLC, DDC), this analog signal must pass through a series of complex processing circuits. Typically, this signal needs to be transmitted over a long distance via wires to a signal processing module, where it is first amplified and then converted into a digital signal by an analog-to-digital converter (A / D) circuit.

[0004] However, the aforementioned existing technical solutions have significant technical drawbacks in practical applications. First, the inherent characteristics of analog signals make them highly susceptible to interference from the external electromagnetic environment during transmission, such as electromagnetic noise generated by power equipment like motors and frequency converters. This introduces noise into the transmitted signal, causing signal deviation and directly affecting the accuracy of the final measurement results. Second, the wires connecting the sensing probe and the signal processing circuit have inherent resistance, which changes with ambient temperature. For resistive sensors (such as NTC and PT100), this introduces additional measurement errors; the longer the wire, the more significant the error. To address these issues, existing technologies have had to employ shielded cables and add filtering circuits, increasing system cost and complexity. Furthermore, due to the manufacturing tolerances of the sensing elements themselves, coupled with the discreteness of components in the back-end analog processing circuit, each transmitter product has a certain inherent error. In order to ensure the accuracy of the products when they leave the factory, a special calibration process must be introduced during the production process. By comparing with a standard temperature source, each product is manually calibrated or compensated by software one by one. This process not only consumes a lot of manpower and time, significantly increasing production costs, but also limits production efficiency.

[0005] Therefore, how to design a liquid temperature transmitter that can fundamentally avoid signal distortion during transmission, while ensuring high accuracy, simplifies the production process, and reduces manufacturing costs has become a pressing technical problem in this field. Utility Model Content

[0006] In order to solve the technical problems existing in the prior art, the present invention provides a digital liquid temperature transmitter, which can help avoid distortion of temperature detection signal transmission in HVAC equipment liquid pipelines and improve measurement accuracy.

[0007] This utility model discloses a digital liquid temperature transmitter, comprising:

[0008] Blind tubes are used to insert into the liquid lines of HVAC equipment;

[0009] A digital temperature sensor is disposed inside the blind tube;

[0010] A digital signal processor is located outside the blind tube;

[0011] The blind tube is inserted into the liquid pipeline of the HVAC equipment at one end and is closed. The inner cavity of the blind tube is sealed and filled with a heat conduction medium. The digital temperature sensor is embedded in the heat conduction medium and is connected to the digital signal processor via a wire to transmit digital signals to the digital signal processor and output temperature data to the outside through the digital signal processor.

[0012] It is understood that in this design, the end of the blind tube in contact with the liquid is a closed end, thus ensuring that the liquid in the pipeline will not leak and preventing the liquid from directly contacting the internal electronic components, ensuring the safety and reliability of the equipment. Furthermore, the entire inner cavity of the blind tube is sealed and filled with a heat-conducting medium, such as thermal grease. The digital temperature sensor is completely embedded or immersed in this heat-conducting medium. On one hand, the heat-conducting medium fills all the gaps between the digital temperature sensor and the inner wall of the blind tube, forming a highly efficient heat conduction path, allowing the temperature of the liquid in the pipeline to be quickly and with low loss transferred to the digital temperature sensor, ensuring the real-time and accurate temperature measurement. On the other hand, the filling medium also plays a role in physical sealing and fixation, effectively preventing external moisture or contaminants from entering the blind tube and corroding the sensor, while also preventing the sensor from shifting or being damaged due to vibration, improving the product's durability and long-term stability.

[0013] In the entire workflow, when the transmitter is installed in the liquid pipeline, the temperature of the liquid inside the pipe is first transferred to the wall of the blind tube. Subsequently, the heat is rapidly transferred to the digital temperature sensor through the heat conduction medium. Unlike traditional analog sensors, this digital temperature sensor integrates a temperature sensing element and a signal digitization processing circuit, directly converting the sensed temperature physical quantity into a digital signal. This digital signal is then transmitted through wires to a digital signal processor outside the blind tube. Because a digital signal is transmitted, it has extremely strong anti-interference capabilities and is largely unaffected by external factors such as wire length and electromagnetic environment, thus ensuring the fidelity of the signal during transmission. Finally, the digital signal processor performs necessary protocol processing or format conversion on the received raw digital signal and outputs temperature data that can be directly read by the user or control system.

[0014] According to the present invention, a digital liquid temperature transmitter includes a digital temperature sensor comprising: a temperature sensing element for detecting temperature and outputting an analog signal; a PCB substrate, the PCB substrate integrating at least: an analog-to-digital converter connected to the temperature sensing element for converting the analog signal into a digital signal; a digital processing unit connected to the analog-to-digital converter for processing the digital signal; and a digital communication interface connected to the digital processing unit for transmitting the processed digital signal externally via the wire.

[0015] According to the present invention, a digital liquid temperature transmitter has a threaded section integrally formed on the outer wall of the blind tube; the blind tube is connected to the side wall of the liquid pipeline of the HVAC equipment through the threaded section.

[0016] According to the present invention, a digital liquid temperature transmitter is provided with a hexagonal nut fixed at the end of the blind tube, so that the blind tube and the threaded section can be rotated by turning the hexagonal nut.

[0017] According to the present invention, a digital liquid temperature transmitter is provided, wherein a sealing ring is fitted onto the outer wall of the blind tube, and the sealing ring abuts between the threaded section and the hexagonal nut.

[0018] According to the present invention, in a digital liquid temperature transmitter, the blind tube is a copper tube or a stainless steel tube.

[0019] According to the present invention, in a digital liquid temperature transmitter, the wall thickness of the blind tube is set to 0.3 mm to 0.8 mm.

[0020] According to the present invention, a digital liquid temperature transmitter is provided, wherein the heat transfer medium is thermally conductive silicone grease.

[0021] According to the present invention, a digital liquid temperature transmitter is provided, wherein the outer periphery of the conductor is wrapped with a sealing sleeve, the sealing sleeve is inserted into the interior of the blind tube and is in sealing contact with the inner wall of the blind tube.

[0022] According to the present invention, a digital liquid temperature transmitter further includes a power supply, which is electrically connected to the digital signal processor.

[0023] The technical advantages of this digital liquid temperature transmitter are as follows: First, by directly employing a digital temperature sensor at the measurement front end, the temperature measurement value is converted into a digital signal at the source, completely avoiding the signal attenuation and distortion problems caused by environmental electromagnetic interference and changes in line impedance during long-distance transmission of traditional analog signals. This significantly improves the accuracy and reliability of temperature measurement. Second, since the accuracy of the output signal is mainly determined by the digital temperature sensor itself and is not affected by the back-end transmission link, there is no need to introduce complex manual calibration procedures to compensate for signal deviations during the manufacturing process. This not only simplifies the production process and saves labor costs but also ensures consistency between product batches. Finally, encapsulating the digital temperature sensor in a blind tube filled with a heat-conducting medium forms a fully sealed integrated structure, effectively preventing external environmental factors such as moisture and dirt from corroding the internal sensing elements. This greatly enhances the product's environmental adaptability and durability, and extends its overall service life. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a diagram showing the usage state of this utility model;

[0026] Figure 2 This is a perspective view of the present invention;

[0027] Figure 3 This is a diagram of the internal structure of this utility model.

[0028] Figure label:

[0029] 1. Blind tube; 2. Digital temperature sensor; 21. Temperature sensing element; 22. PCB substrate; 3. Digital signal processor; 4. Heat transfer medium; 5. Wire; 6. Threaded section; 7. Hex nut; 8. Sealing ring; 9. Sealing sleeve; 10. Power supply. Detailed Implementation

[0030] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this utility model.

[0031] like Figures 1 to 3 As shown, this embodiment of a digital liquid temperature transmitter is mainly used in applications such as central air conditioning systems, central air conditioning terminal equipment, and HVAC control systems where temperature detection of liquid pipelines is required. The transmitter mainly includes a blind tube 1 for inserting into the liquid pipeline to be measured, a digital temperature sensor 2 disposed inside the blind tube 1, and a digital signal processor 3 located outside the blind tube 1.

[0032] Specifically, the blind tube 1 is a hollow tubular structure with a closed end extending into the liquid pipeline to prevent liquid from entering the inner cavity of the blind tube 1. The blind tube 1 can be made of a metal material with good thermal conductivity and corrosion resistance, such as copper or stainless steel, to ensure rapid and stable transfer of the temperature of the liquid in the external pipeline to its interior, while also guaranteeing its service life in humid environments. To achieve optimal heat transfer efficiency while ensuring structural strength, the wall thickness of the blind tube 1 is preferably set to 0.5 mm. Too thin a wall thickness may lead to insufficient structural strength and easy damage during installation or use; while too thick a wall thickness will increase thermal resistance, affecting the response speed and sensitivity of temperature measurement.

[0033] The inner cavity of the blind tube 1 is sealed and filled with a heat-conducting medium 4, preferably thermally conductive silicone grease. The digital temperature sensor 2 is completely embedded and covered by the heat-conducting medium 4. The filling function of the thermally conductive silicone grease is twofold: firstly, it can completely fill all the gaps between the digital temperature sensor 2 and the inner wall of the blind tube 1, forming a continuous heat conduction path without air layers, thereby greatly improving the heat conduction efficiency from the outer wall of the blind tube 1 to the digital temperature sensor 2, ensuring the real-time performance and accuracy of temperature measurement; secondly, it can firmly fix the digital temperature sensor 2 near the closed end of the blind tube 1, and play a buffering and protective role.

[0034] The core of this embodiment lies in the use of a digital temperature sensor 2. The digital temperature sensor 2 is electrically connected to an external digital signal processor 3 via wires 5. Unlike existing technologies that use analog sensing elements such as NTC thermistors or PT100, the digital temperature sensor 2 in this embodiment is itself an integrated miniature system. Specifically, the digital temperature sensor 2 includes a temperature sensing element 21 and a PCB substrate 22. The temperature sensing element 21 is responsible for sensing the temperature transmitted by the heat conduction medium 4 and generating an analog electrical signal corresponding to the temperature. Integrating the temperature sensing element 21 tightly onto the same PCB substrate 22 are at least an analog-to-digital converter, a digital processing unit, and a digital communication interface.

[0035] The working process is as follows: The analog signal generated by the temperature sensing element 21 is immediately sent to the analog-to-digital converter, where the conversion from analog to digital signal is completed locally inside the sensor. Subsequently, the digital processing unit can perform necessary processing on the digital signal, such as linearization correction, filtering, or compensation. Finally, the processed temperature data is transmitted directly to the external digital signal processor 3 via the wire 5 through the digital communication interface using a standard digital bus protocol (such as single-bus protocol, I2C protocol, etc.).

[0036] The significant technical advantage of this structure is that, because the analog-to-digital conversion process is completed within the sensor, which has very few sources of interference, the transmitted signal is a digital signal with high anti-interference capability. This fundamentally avoids the signal attenuation and distortion problems caused by environmental electromagnetic interference and changes in line impedance during long-distance transmission of analog signals in traditional technologies. This directly ensures the high accuracy and stability of the final measurement results. Furthermore, since the sensor is calibrated at the factory, the entire transmitter does not require tedious manual calibration procedures during production, thus saving production costs and improving production efficiency.

[0037] For ease of installation and fixation, the outer wall of the blind conduit 1 is integrally formed with a threaded section 6. During installation, the threaded section 6 of the blind conduit 1 can be directly screwed into the pre-set threaded hole on the side wall of the HVAC equipment liquid pipeline. To facilitate tightening, a hexagonal nut 7 is fixedly installed at the outer end of the blind conduit 1. Users can use standard tools such as wrenches to clamp and rotate the hexagonal nut 7, thereby rotating the entire blind conduit 1 to achieve quick and reliable installation.

[0038] To ensure a tight seal at the installation interface and prevent liquid leakage, a sealing ring 8 is fitted onto the outer wall of the blind pipe 1. This sealing ring 8 is preferably made of oil-resistant, high-temperature-resistant rubber or polytetrafluoroethylene (PTFE), and its installation position is between the root of the threaded section 6 and the end face of the hexagonal nut 7. When the hexagonal nut 7 is tightened, the sealing ring 8 is pressed between the hexagonal nut 7 and the outer wall of the pipe, forming a reliable static seal and effectively preventing liquid leakage from the installation gap.

[0039] Furthermore, to protect the lead wire 5 and further enhance the sealing performance of the entire device, a sealing sleeve 9 is wrapped around the outer periphery of the lead wire 5. One end of the sealing sleeve 9 extends and inserts into the opening of the blind tube 1, and is press-fitted to the inner wall of the blind tube 1 or bonded with sealant to form a tight seal. This not only protects the internal lead wire 5 from mechanical damage, but more importantly, it works together with the internally filled thermally conductive silicone grease 4 to form a solid barrier, completely preventing external dirt and moisture from intruding into the blind tube 1 through the gaps in the lead wire, ensuring the long-term stable operation of the digital temperature sensor 2 and significantly extending the service life of the entire transmitter.

[0040] Finally, this digital liquid temperature transmitter also includes a power supply 10, which is electrically connected to the digital signal processor 3 via wires, providing a stable operating voltage for the digital signal processor 3 and the digital temperature sensor 2 connected thereto. After receiving the pure digital temperature signal from the digital temperature sensor 2, the digital signal processor 3 can perform format conversion or protocol conversion on the data according to the requirements of the host computer or control system, and finally output temperature data that can be directly used by the user.

[0041] In summary, this invention achieves on-site digitization of temperature signals by placing a digital temperature sensor with integrated analog-to-digital conversion function inside a blind tube filled with a heat-conducting medium. This effectively solves the problem of inaccurate measurements caused by interference in analog signal transmission, eliminates the need for production calibration, and reduces costs. Furthermore, the threaded connection and multi-seal structure design ensure convenient and reliable installation as well as long-term durability, giving it high practical value and market competitiveness.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A digital liquid temperature transmitter, characterized in that, include: Blind tube (1), used for insertion into the liquid piping of HVAC equipment; A digital temperature sensor (2) is disposed inside the blind tube (1); A digital signal processor (3) is located outside the blind tube (1); The blind tube (1) is inserted into the liquid pipeline of the HVAC equipment at one end and is closed. The inner cavity of the blind tube (1) is sealed and filled with a heat conduction medium (4). The digital temperature sensor (2) is embedded in the heat conduction medium (4) and is connected to the digital signal processor (3) via a wire (5) to transmit digital signals to the digital signal processor (3) and output temperature data to the outside through the digital signal processor (3).

2. The digital liquid temperature transmitter according to claim 1, characterized in that, The digital temperature sensor (2) includes: Temperature sensing element (21) is used to detect temperature and output analog signal; PCB substrate (22), wherein the PCB substrate (22) integrates at least: An analog-to-digital converter, connected to the temperature sensing element, is used to convert the analog signal into a digital signal; A digital processing unit, connected to the analog-to-digital converter, is used to process the digital signal; A digital communication interface is connected to the digital processing unit and is used to transmit processed digital signals outward through the wire (5).

3. The digital liquid temperature transmitter according to claim 1, characterized in that, The outer wall of the blind tube (1) is integrally formed with a threaded section (6); The blind pipe (1) is connected to the side wall of the liquid pipeline of the HVAC equipment through the threaded section (6).

4. The digital liquid temperature transmitter according to claim 3, characterized in that, The end of the blind tube (1) is fixedly provided with a hexagonal nut (7) so that the blind tube (1) and the threaded section (6) can be rotated by turning the hexagonal nut (7).

5. The digital liquid temperature transmitter according to claim 4, characterized in that, The outer wall of the blind tube (1) is fitted with a sealing ring (8), which abuts between the threaded section (6) and the hexagonal nut (7).

6. The digital liquid temperature transmitter according to claim 1, characterized in that, The blind tube (1) is made of copper or stainless steel.

7. The digital liquid temperature transmitter according to claim 1, characterized in that, The wall thickness of the blind tube (1) is set to be between 0.3 mm and 0.8 mm.

8. The digital liquid temperature transmitter according to claim 1, characterized in that, The heat conduction medium (4) is set as thermally conductive silicone grease.

9. The digital liquid temperature transmitter according to claim 1, characterized in that, The outer periphery of the conductor (5) is wrapped with a sealing sleeve (9), which is inserted into the inside of the blind tube (1) and seals against the inner wall of the blind tube (1).

10. The digital liquid temperature transmitter according to claim 1, characterized in that, It also includes a power supply (10) which is electrically connected to the digital signal processor (3).

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