Floor heating pipe material heat conduction capacity comparison test device
By designing a comparative testing device for the thermal conductivity of underfloor heating pipes, the thermal conductivity testing process has been simplified, solving the problems of complex testing and high cost in existing technologies. This enables rapid and intuitive comparison of thermal conductivity, thereby improving product quality stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JINGHUA PLASTICS CO LTD
- Filing Date
- 2025-07-08
- Publication Date
- 2026-06-12
AI Technical Summary
Existing methods for testing the thermal conductivity of underfloor heating pipes are complex, costly, and inefficient, making it difficult to quickly and intuitively compare the thermal conductivity of multi-layer composite pipes made of different materials, which affects the stability of product quality.
A comparative testing device for the thermal conductivity of underfloor heating pipes was designed, including a constant temperature water tank, a temperature display timer, and a sealing end cap. The thermal conductivity is evaluated by measuring the time it takes for the liquid temperature inside the pipe to change, which simplifies the testing process, reduces costs, and improves testing efficiency.
It enables a simple and quick comparative test of thermal conductivity, allowing direct comparison of multi-layer composite pipes made of different materials, thus improving product quality stability and quality control capabilities during the production process.
Smart Images
Figure CN224354359U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of pipe testing, and in particular to a comparative testing device for the thermal conductivity of underfloor heating pipes. Background Technology
[0002] With the increasing application of radiant floor heating in home heating, people have higher and higher requirements for the performance of underfloor heating pipes. However, ordinary PERT and PPR pipes have low thermal conductivity, which can affect the heat dissipation speed of underfloor heating systems. Therefore, the thermal conductivity of underfloor heating pipes has gradually become an important evaluation indicator for underfloor heating pipe products, and also a key quality control item that underfloor heating pipe manufacturers need to focus on during the production process. However, due to the diverse manufacturing processes of underfloor heating pipes, different manufacturers, different raw materials, different formulas, and different equipment produce underfloor heating pipes with inconsistent thermal conductivity. Therefore, it is necessary to establish effective testing and analysis methods for the quality control of the thermal conductivity of underfloor heating pipes in order to effectively regulate the market and ensure the quality stability of the thermal conductivity of underfloor heating pipe products.
[0003] Currently, the quality inspection method for the thermal conductivity of underfloor heating pipes involves measuring the thermal conductivity coefficient. However, the equipment for measuring thermal conductivity is expensive and the operation is complex. Furthermore, when comparing the thermal conductivity of multiple pipe samples, the thermal conductivity of each sample must be tested separately before comparison and evaluation, resulting in long testing cycles, low efficiency, and high costs. Additionally, this method requires preparing raw material samples before comparing their thermal conductivity, rather than directly comparing samples. Sample preparation is complex, comparisons are not intuitive, and the quality evaluation method is cumbersome. Moreover, it limits the comparison of thermal conductivity for multi-layer composite pipes made of different materials. Therefore, current methods for testing the thermal conductivity of underfloor heating pipes still have some shortcomings, hindering companies from improving their ability to quickly inspect, evaluate, and ensure the quality of underfloor heating pipe products during production, thus affecting the quality stability of the thermal conductivity of underfloor heating pipe products. Summary of the Invention
[0004] This utility model provides a comparative testing device for the thermal conductivity of underfloor heating pipes. This device allows for a simple and quick comparison of the thermal conductivity of different pipe materials, and also enables comparative evaluation of the quality of the thermal conductivity of underfloor heating pipes during the production process, thereby improving the quality stability of the product's thermal conductivity. The specific technical solution is as follows:
[0005] A comparative testing device for the thermal conductivity of underfloor heating pipes includes a constant temperature water tank. The constant temperature water tank is filled with water, has a lid on top, and a constant temperature heater at the bottom. The heater heats the water in the tank to ensure it remains within the required temperature range. The lid has two ports connected to the inside of the tank, each with left and right contacts connected to a temperature display timer via wiring. The pipe to be tested is sealed at the bottom, filled with liquid, and has a sealing cap at the top. The pipe is inserted into the tank through the ports, with its lower end immersed in the water. The upper end is fixed to the ports by the sealing cap, which has a probe in the center. One end of the probe is inserted into the pipe and immersed in the liquid, while the other end is connected to the temperature display timer via wiring.
[0006] Furthermore, the temperature measurement display timer includes a housing and a circuit board disposed inside the housing. The circuit board is provided with a microprocessor, a temperature measurement module, a timing module, an input keyboard, a time display, and a temperature display. The temperature measurement module, timing module, input keyboard, time display, and temperature display are electrically connected to the microprocessor through wires. The input keyboard, time display, and temperature display are disposed on the outer surface of the housing. The temperature T can be preset through the input keyboard as the endpoint temperature of the liquid inside the pipe to be measured.
[0007] The timing module is connected to the left and right contacts via a line. After the pipe to be tested is placed in the work station, the sealing cap at its upper end triggers the left and right contacts, and the timing module starts timing.
[0008] The temperature measurement module is connected to the probe via a line. The probe measures the initial temperature T1 of the liquid inside the pipe. As time increases, the constant temperature water outside the pipe continuously transfers heat to the liquid inside the pipe, causing the temperature of the liquid inside the pipe to rise continuously. When the temperature of the liquid inside the pipe reaches the preset temperature T, the timing module stops timing and records the time t, which is the time taken for the liquid inside the pipe to go from the initial temperature T1 to the final temperature T.
[0009] The temperature display shows the preset endpoint temperature T and the initial temperature T1 of the liquid inside the pipe; the time display shows the time t taken for the liquid inside the pipe to rise from the initial temperature T1 to the endpoint temperature T.
[0010] Furthermore, a reset button is also provided on the circuit board. The reset button is exposed outside the housing and is electrically connected to the microprocessor through a wire. After the initial temperature T1, the final temperature T and the time t of the liquid inside the pipe are recorded, the pipe is removed and the reset button is clicked to clear the data display and reset the temperature display timer to wait for the new test.
[0011] Furthermore, the circuit board is also equipped with a memory and a communication unit. The memory and the communication unit are electrically connected to the microprocessor via wires. The memory is used to store the signals processed by the microprocessor. The records in the memory can be retrieved by inputting the keyboard and displayed on the display. The communication unit can connect and send the signals processed by the microprocessor to external devices.
[0012] Furthermore, a power supply, which is a lithium battery, is also installed inside the casing. The power supply is connected to the microprocessor and provides power to the various units on the circuit board through the microprocessor.
[0013] Furthermore, the cover is equipped with sealing grooves near both workstation openings. After the pipe to be tested enters the constant temperature water tank through the workstation opening, the sealing end cap at the upper end of the pipe to be tested fits tightly with the sealing groove.
[0014] Furthermore, the sealing end cap includes a top cover, an end cap ring at the lower end of the top cover, and an end cap inner seat inside the end cap ring. The end cap inner seat is provided with an upper sealing ring and a lower sealing ring. The probe penetrates the sealing end cap and is placed inside the pipe to be tested. The end cap inner seat extends into the pipe, so that the upper and lower sealing rings of the end cap inner seat are tightly fitted with the inner wall of the pipe to be tested to form a sealed space, which plays a role in double sealing, heat insulation and fixing of the pipe. The end cap ring is tightly fitted with the sealing groove at the work station opening to achieve sealing and heat insulation. The outer layer of the sealing end cap is provided with a heat insulation layer, which can provide heat insulation for the sealing end cap.
[0015] Furthermore, the liquid inside the pipe being tested is either distilled water or heat transfer oil.
[0016] The constant temperature water tank is equipped with an insulation layer on the outside, which can keep the constant temperature water tank warm and insulated.
[0017] Two temperature display timers are set on the front surface of the constant temperature water tank.
[0018] This utility model features a simple structure and reasonable design. This device allows for quick and easy comparative testing of the thermal conductivity of underfloor heating pipes, particularly comparing the thermal conductivity of multi-layer composite pipes made of different materials. It allows for direct comparison testing via pipe samples, providing intuitive and efficient testing with a short cycle time and low cost. This device enables rapid and comprehensive evaluation of the thermal conductivity of underfloor heating pipes. During the production process, it allows for direct comparison of the thermal conductivity of different batches of underfloor heating pipes with standard samples, and also monitors fluctuations in the thermal conductivity of different batches. By comparing the thermal conductivity of underfloor heating pipes from multiple dimensions, including the degree of deviation, quality inspection and evaluation can be conducted, thereby improving the quality assessment system for the thermal conductivity of underfloor heating pipes and better ensuring the quality of underfloor heating pipe products. Attached Figure Description
[0019] Figure 1 This is a front view of the testing device of this utility model;
[0020] Figure 2 This is a top view of the testing device of this utility model;
[0021] Figure 3 This is a schematic diagram of the structure of the testing device of this utility model, in which the pipe to be tested is placed.
[0022] Figure 4 This is a schematic diagram of the sealing end cap of this utility model;
[0023] Figure 5 yes Figure 4 A cross-sectional view of surface AA;
[0024] Figure 6 This is a structural block diagram of the temperature display timer of the testing device of this utility model. Detailed Implementation
[0025] To better understand the purpose, function, and specific design scheme of this utility model, the following description, in conjunction with the accompanying drawings, provides a more detailed account of the comparative testing device, testing method, and evaluation method for the thermal conductivity of underfloor heating pipes.
[0026] like Figures 1-3 As shown, the thermal conductivity comparison testing device for underfloor heating pipes of this utility model includes a constant temperature water tank 1, which is filled with water. A cover 2 is installed on the top of the constant temperature water tank 1, and a constant temperature heater 3 is installed at the bottom. The heater 3 heats the water in the constant temperature water tank 1 to ensure that the water temperature remains within the required range. The cover 2 has a first working port 21 and a second working port 22, both of which communicate with the interior of the constant temperature water tank 1. The first working port 21 has a left contact 25 and a right contact 26, which are connected to their corresponding temperature display timers 4 via circuits. The second working port 22 has a left contact 27 and a right contact 28, which are connected to their corresponding temperature display timers 5 via circuits. The two temperature display timers are located on the front surface of the constant temperature water tank 1.
[0027] The bottom of the pipe 6 to be tested is closed, the inside is filled with liquid, and the upper end is equipped with a sealing cap 7. The liquid inside the pipe 6 is distilled water or heat transfer oil. The pipe 6 to be tested is inserted into the constant temperature water tank 1 through the station port. The lower end of the pipe 6 to be tested is immersed in the water in the constant temperature water tank 1. The upper end of the pipe 6 to be tested is fixed at the station port by the sealing cap 7. A probe 76 is set in the middle of the sealing cap 7. One end of the probe 76 is inserted into the pipe to be tested and immersed in distilled water or heat transfer oil. The other end of the probe 76 is connected to the corresponding temperature display timer through a circuit.
[0028] like Figure 6 As shown, the two temperature display timers have the same structure. For ease of description, one of the temperature display timers is taken as an example. The temperature display timer includes a housing and a circuit board disposed inside the housing. The circuit board is provided with a microprocessor, a temperature measurement module, a timing module, an input keyboard, a time display, and a temperature display. The temperature measurement module, timing module, input keyboard, time display, and temperature display are electrically connected to the microprocessor through wires. The input keyboard, time display, and temperature display are disposed on the outer surface of the housing. The temperature T can be preset through the input keyboard as the endpoint temperature of the liquid inside the pipe to be measured.
[0029] The timing module is connected to the left and right contacts via a circuit. After the pipe to be tested is placed in the workstation, the sealing cap at its upper end triggers the left and right contacts, and the timing module starts timing.
[0030] The temperature measurement module is connected to the probe via a circuit. The probe measures the initial temperature T1 of the liquid inside the pipe. As time increases, the constant temperature water outside the pipe continuously transfers heat to the liquid inside the pipe, causing the temperature of the liquid inside the pipe to rise continuously. When the temperature of the liquid inside the pipe reaches the preset temperature T, the timing module stops timing and records the time t, which is the time taken for the liquid inside the pipe to go from the initial temperature T1 to the final temperature T.
[0031] The temperature display shows the preset endpoint temperature T and the initial temperature T1 of the liquid inside the pipe, while the time display shows the time t taken for the liquid inside the pipe to rise from the initial temperature T1 to the endpoint temperature T.
[0032] The circuit board is also equipped with a reset button, which is exposed outside the housing and electrically connected to the microprocessor through a wire. After the initial temperature T1, the final temperature T and the time t of the liquid in the tube are recorded, the tube is removed and the reset button is clicked to clear the data display and reset the temperature display timer to wait for the new test.
[0033] The circuit board also includes a memory and a communication unit. The memory and communication unit are electrically connected to the microprocessor via wires. The memory is used to store signals processed by the microprocessor. Records in the memory can be retrieved by inputting a keyboard and displayed on a monitor. The communication unit can send signals processed by the microprocessor to external devices.
[0034] The housing also houses a power supply, which is a lithium battery. The power supply is connected to the microprocessor and provides power to the various units on the circuit board through the microprocessor.
[0035] like Figures 1-3 As shown, the cover 2 has sealing grooves 23 and 24 near the two workstation openings. After the pipe 6 to be tested enters the constant temperature water tank 1 through the workstation opening, the sealing end cap 7 at the upper end of the pipe 6 to be tested fits tightly with the sealing groove. The constant temperature water tank 1 is provided with an insulation layer 11, which can keep the constant temperature water tank 1 warm.
[0036] like Figure 4 and Figure 5 As shown, the sealing end cap 7 includes a top cover 71, an end cap ring 72 at the lower end of the top cover 71, and an end cap inner seat 75 inside the end cap ring 72. The end cap inner seat 75 is provided with an upper sealing ring 73 and a lower sealing ring 74. The probe 76 penetrates the sealing end cap 7 and is placed inside the pipe 6 to be tested. The end cap inner seat 75 extends into the pipe, so that the upper and lower sealing rings of the end cap inner seat 75 are tightly fitted with the inner wall of the pipe to be tested, forming a double sealing, heat insulation and pipe fixing function. The end cap ring 72 is tightly fitted with the sealing groove at the station opening to achieve sealing and heat insulation functions.
[0037] This device can be used to compare and test the thermal conductivity of underfloor heating pipes. The specific steps are as follows:
[0038] Step 1: Cut equal lengths of the pipes to be compared according to the same specifications and dimensions. Seal the lower end of the pipe with a heat-insulating pipe plug. Add the same mass of the same liquid into the pipe from the upper end. The liquid can be distilled water or heat transfer oil. Seal the sealing cap on the upper end of the pipe. Insert the probe into the pipe and immerse it in the liquid to obtain the pipe sample to be compared.
[0039] Step 2: Heat the water in the constant temperature water tank to the required temperature, and wait for the water temperature in the constant temperature water tank to stabilize;
[0040] Step 3: Pre-set the temperature T by inputting the keypad, which will be the endpoint temperature of the liquid inside the pipe to be tested and displayed on the temperature display.
[0041] Step 4: Place the pipe samples to be compared in an environment with the same temperature for conditioning. After the initial temperature of the liquid inside the pipe is the same, quickly place the two pipe samples to be compared into their respective workstations. The initial temperature T1 of the liquid inside the pipe is transmitted to the temperature measurement module through the probe and displayed on the temperature display.
[0042] Step 5: When the sealing cap at the upper end of the pipe under test triggers the left and right contacts, the timing module starts timing;
[0043] Step 6: As time increases, the constant temperature water outside the pipe continuously transfers heat to the liquid inside the pipe, causing the temperature of the liquid inside the pipe to rise continuously. When the temperature of the liquid inside the pipe reaches the preset temperature T, the timing module stops timing and records the time t, which is the time taken for the liquid inside the pipe to go from the initial temperature T1 to the final temperature T, and displays it through the time display.
[0044] Step 7: Record the time t1 taken for the liquid inside the pipe at station 1 to rise from the initial temperature T1 to the final temperature T using the temperature display timer corresponding to station 1. Record the time t2 taken for the liquid inside the pipe at station 2 to rise from the initial temperature T1 to the final temperature T using the temperature display timer corresponding to station 2. Compare the thermal conductivity of the pipes at station 1 and station 2.
[0045]
[0046] R represents the comparative evaluation value of thermal conductivity; This represents the time (in seconds) taken for the liquid inside the pipe at station 1 to rise from the initial temperature T1 to the final temperature T. This represents the time (in seconds) taken for the liquid inside the pipe at station 2 to rise from the initial temperature T1 to the final temperature T.
[0047] When R > 1, the thermal conductivity of the pipe at station 1 is better than that of the pipe at station 2.
[0048] When R < 1, the thermal conductivity of the pipe at station 2 is better than that of the pipe at station 1.
[0049] When R=1, the thermal conductivity of the pipe at station 1 is the same as that of the pipe at station 2.
[0050] The above methods can be used to compare and evaluate the thermal conductivity of pipes used in different workstations.
[0051] This device can also be used to conduct a comprehensive evaluation of the thermal conductivity of underfloor heating pipes through comparative testing. The specific steps are as follows:
[0052] Step 1: Obtain comparative samples: Sampling is carried out on the current production batch of underfloor heating pipes according to the preset sampling plan, and a sampling sample of quantity n is obtained, where n represents the number of sampling samples; the sampling sample is denoted as N. i Let i = 1, 2, ..., n; Based on the preset quality requirements, determine the preset standard sample of the underfloor heating pipe and denote it as N. s ;
[0053] Step 2: Comparative test of the thermal conductivity of underfloor heating pipe samples:
[0054] S1: Sample N of the current production batch of pipes to be compared. i and preset standard sample N s Cut equal lengths of pipe to the same specifications and seal the lower end of the pipe with an insulated pipe plug. Add the same mass of the same liquid (distilled water or heat-conducting oil) into the pipe from the upper end. Seal the upper end of the pipe with a sealing cap, and insert the probe into the pipe and immerse it in the liquid. Prepare sampling samples N. i and preset standard sample N s The pipe sample to be tested;
[0055] S2: Heat the water in the constant temperature water tank to the required temperature, and wait for the water temperature in the constant temperature water tank to remain constant;
[0056] S3: The temperature T is preset by inputting the keyboard and used as the endpoint temperature of the liquid inside the pipe to be tested, which is then displayed on the temperature display.
[0057] S4: Place the pipe samples to be compared in an environment with the same temperature for conditioning. Once the initial temperature of the liquid inside the pipes is the same, quickly place the two pipe samples to be compared into their respective workstations. The sampling sample N... i The pipe sample to be tested is placed in station 1, and the preset standard sample N is placed in the station 1. s The pipe sample to be tested is placed in station 2; the initial temperature T1 of the liquid inside the pipe is transmitted to the temperature measurement module through the probe and displayed by the temperature display.
[0058] S5: When the sealing cap at the upper end of the pipe under test triggers the left and right contacts, the timing unit starts timing;
[0059] S6: As time increases, the constant-temperature water outside the pipe continuously transfers heat to the liquid inside the pipe, causing the temperature of the liquid inside the pipe to rise continuously. When the temperature of the liquid inside the pipe reaches the preset temperature T, the timing module stops timing and records the time t, that is, the time taken for the liquid inside the pipe to rise from the initial temperature T1 to the final temperature T, and displays it through the time display. The time displays corresponding to station 1 and station 2 respectively record the sampling sample N of station 1. iThe time t taken for the liquid inside the pipe to rise from the initial temperature T1 to the final temperature T 1i and station 2 preset standard sample N s The time t taken for the liquid inside the pipe to rise from the initial temperature T1 to the final temperature T 2i ;
[0060] Step 3: Comparative evaluation of the thermal conductivity of underfloor heating pipe samples:
[0061] R is calculated using the comparative evaluation formula. i ,
[0062]
[0063] Where R i t represents the comparative evaluation value of the thermal conductivity of the i-th sample. 1i N represents the workstation 1 sampled for the i-th sample comparison test. i The time (s) taken for the liquid inside the pipe to rise from the initial temperature T1 to the final temperature T; t 2i The station 2 for the comparative test of the i-th sample represents the preset standard sample N. s The time (s) taken for the liquid inside the pipe to rise from the initial temperature T1 to the final temperature T.
[0064] Through R i Thermal conductivity comparison evaluation value for sample N i Compared with the preset standard sample N s The thermal conductivity of each component was compared and evaluated:
[0065] When R i When N > 1, the sample size is N. i Its thermal conductivity is better than that of the preset standard sample N. s Thermal conductivity;
[0066] When R i When <1, the preset standard sample N s Its thermal conductivity is better than that of the sample N. i Thermal conductivity;
[0067] When R i When =1, the sample N i The thermal conductivity of the standard sample N is similar to that of the standard sample N. s They have the same thermal conductivity;
[0068] Step 4: Stability evaluation of the thermal conductivity of the underfloor heating pipe samples:
[0069] Calculate s using the following analytical formula. i :
[0070]
[0071] Where s i R represents the evaluation value of the thermal conductivity deviation of the i-th sample; i This represents the comparative evaluation value of the thermal conductivity of the i-th sample.
[0072] Through the thermal conductivity deviation value s i For sample N i Compared with the preset standard sample N s The degree of deviation in thermal conductivity is analyzed and compared with the pre-set threshold requirement s0 for thermal conductivity deviation evaluation:
[0073] When s i When ≤s0, the sample size N i Compared with the preset standard sample N s The deviation in thermal conductivity meets the preset requirements;
[0074] When s i When s > 0, the sample size N i Compared with the preset standard sample N s The thermal conductivity deviation does not meet the preset requirements;
[0075] Step 5: Conduct a comprehensive evaluation of the thermal conductivity of the current batch of underfloor heating pipes and generate a quality inspection report.
[0076] Statistical analysis of R based on the following formula i The number of times M is greater than or equal to 1:
[0077]
[0078] Where M is the thermal conductivity comparison evaluation factor, representing R i The number of times ≥1; n represents the number of samples; R i This represents the comparative evaluation value of the thermal conductivity of the i-th sample.
[0079] Based on the following analytical formula, s is statistically analyzed. i The number of times K ≥ s0:
[0080]
[0081] Where K is the thermal conductivity deviation evaluation factor, representing s i The number of times ≥s0; n represents the number of samples; s i s0 represents the deviation evaluation value of the thermal conductivity of the i-th sample; s0 represents the pre-set threshold requirement for the deviation evaluation value of thermal conductivity.
[0082] The thermal conductivity evaluation factor M and the thermal conductivity deviation evaluation factor K are compared with the pre-set threshold requirements M0 and K0, respectively, to comprehensively evaluate the thermal conductivity of the current batch of floor heating pipes.
[0083] When M≥M0 and K≤K0, the comprehensive evaluation of the thermal conductivity of the current production batch of floor heating pipes meets the preset requirements and is judged to be qualified;
[0084] When M≥M0 and K>K0, the overall evaluation of the thermal conductivity of the current production batch of floor heating pipes does not meet the preset requirements and is judged as unqualified.
[0085] When M < M0, the overall evaluation of the thermal conductivity of the current production batch of floor heating pipes does not meet the preset requirements and is judged as unqualified.
[0086] Where M0 represents the threshold requirement of the pre-set thermal conductivity comparison evaluation factor; K0 represents the threshold requirement of the pre-set thermal conductivity deviation evaluation factor.
[0087] 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 comparative testing device for the thermal conductivity of underfloor heating pipes, comprising a constant temperature water tank, characterized in that, The constant temperature water tank is filled with water and has a lid on top. A constant temperature heater is located at the bottom of the tank to heat the water, ensuring it remains within the required temperature range. The lid has two ports that connect to the inside of the tank and are equipped with left and right contacts, which are connected to a temperature display timer via wiring. The pipe to be tested is sealed at the bottom, filled with liquid, and has a sealing cap at the top. The pipe is inserted into the tank through the ports, with its lower end immersed in the water. The upper end of the pipe is fixed to the ports by the sealing cap, which has a probe in the center. One end of the probe is inserted into the pipe and immersed in the liquid, while the other end is connected to the temperature display timer via wiring.
2. The comparative testing device for the thermal conductivity of underfloor heating pipes according to claim 1, characterized in that: The temperature measurement display timer includes a housing and a circuit board disposed inside the housing. The circuit board is provided with a microprocessor, a temperature measurement module, a timing module, an input keyboard, a time display, and a temperature display. The temperature measurement module, timing module, input keyboard, time display, and temperature display are electrically connected to the microprocessor through wires. The input keyboard, time display, and temperature display are disposed on the outer surface of the housing. The temperature T can be preset through the input keyboard as the endpoint temperature of the liquid inside the pipe to be measured. The timing module is connected to the left and right contacts via a line. After the pipe to be tested is placed in the work station, the sealing cap at its upper end triggers the left and right contacts, and the timing module starts timing. The temperature measurement module is connected to the probe via a line. The probe measures the initial temperature T1 of the liquid inside the pipe. As time increases, the constant temperature water outside the pipe continuously transfers heat to the liquid inside the pipe, causing the temperature of the liquid inside the pipe to rise continuously. When the temperature of the liquid inside the pipe reaches the preset temperature T, the timing module stops timing and records the time t, which is the time taken for the liquid inside the pipe to go from the initial temperature T1 to the final temperature T. The temperature display shows the preset endpoint temperature T and the initial temperature T1 of the liquid inside the pipe; the time display shows the time t taken for the liquid inside the pipe to rise from the initial temperature T1 to the endpoint temperature T.
3. The comparative testing device for the thermal conductivity of underfloor heating pipes according to claim 2, characterized in that: The circuit board is also equipped with a reset button, which is exposed outside the housing and electrically connected to the microprocessor via a wire. After recording the initial temperature T1, the final temperature T, and the time t of the liquid inside the pipe, the pipe can be removed and the reset button can be clicked to clear the data display and reset the temperature display timer to wait for the new test.
4. The comparative testing device for the thermal conductivity of underfloor heating pipes according to claim 2, characterized in that: The circuit board also includes a memory and a communication unit. The memory and communication unit are electrically connected to the microprocessor via wires. The memory stores the signals processed by the microprocessor. The records in the memory can be retrieved by inputting the keyboard and displayed on the monitor. The communication unit can send the signals processed by the microprocessor to external devices.
5. The comparative testing device for the thermal conductivity of underfloor heating pipes according to claim 2, characterized in that: The housing also houses a power supply, which is a lithium battery. The power supply is connected to the microprocessor and provides power to the various units on the circuit board through the microprocessor.
6. The comparative testing device for the thermal conductivity of underfloor heating pipes according to claim 1, characterized in that: The cover of the test chamber is equipped with sealing grooves near the two workstation openings. After the test pipe enters the constant temperature water tank through the workstation opening, the sealing end cap at the upper end of the test pipe fits tightly with the sealing groove.
7. The comparative testing device for the thermal conductivity of underfloor heating pipes according to claim 6, characterized in that: The sealing end cap includes a top cover, an end cap ring at the lower end of the top cover, and an inner end cap seat inside the end cap ring. The inner end cap seat has an upper sealing ring and a lower sealing ring. The probe penetrates the sealing end cap and is placed inside the pipe to be tested. The inner end cap seat extends into the pipe, so that the upper and lower sealing rings of the inner end cap seat fit tightly against the inner wall of the pipe to form a sealed space, providing double sealing, heat insulation, and pipe fixation. The end cap ring fits tightly against the sealing groove at the workstation opening, achieving sealing and heat insulation. The outer layer of the sealing end cap has an insulation layer, which provides heat insulation for the sealing end cap.
8. The comparative testing device for the thermal conductivity of underfloor heating pipes according to claim 1, characterized in that: The liquid inside the pipe being tested is either distilled water or heat transfer oil.
9. The comparative testing device for the thermal conductivity of underfloor heating pipes according to claim 1, characterized in that: The constant temperature water tank is equipped with an insulation layer on the outside, which can keep the constant temperature water tank warm and insulated.
10. The comparative testing device for the thermal conductivity of underfloor heating pipes according to claim 1, characterized in that: Two temperature display timers are set on the front surface of the constant temperature water tank.