A device and method for rapid detection of the heat transfer coefficient of a building wall

Abstract

The application discloses a kind of building wall heat transfer coefficient rapid detection device, including electric heater, heat flow sensor component, temperature detection component and controller, electric heater is installed on the wall to be measured, electric heater has main heating zone and guard ring heating zone, and main heating zone and guard ring heating zone are concentrically arranged;Heat flow sensor component includes several heat flow sensors, heat flow sensor is installed on the wall to be measured, and heat flow sensor is located in main heating zone;Temperature detection component includes two high-precision temperature sensors, high-precision temperature sensor is installed on the both sides of the wall to be measured, and high-precision temperature sensor is correspondingly arranged with main heating zone;Controller is electrically connected with electric heater, heat flow sensor, high-precision temperature sensor respectively.The application suppresses lateral heat diffusion by guard ring heating zone, cooperates heat flow sensor to directly measure the heat flux density of wall, significantly shortens detection time and improves the calculation precision of heat transfer coefficient.

Description

Technical Field

[0001] This invention relates to the field of on-site testing technology in building engineering, and in particular to a rapid testing device and method for the heat transfer coefficient of building walls. Background Technology

[0002] The heat transfer coefficient (K-value) of building exterior walls is a core indicator for measuring the thermal insulation performance of walls, and it directly affects the evaluation of building energy-saving design compliance and on-site acceptance judgment.

[0003] Currently, the mainstream method for on-site testing of wall heat transfer coefficients in building construction is the heat flux method. This method involves placing heat flux meters and temperature sensors on both sides of the wall, monitoring a stable heat flux over a long period under natural temperature differences, and then calculating the heat transfer coefficient. Its main disadvantages are: long testing time, typically requiring continuous monitoring for several to tens of hours; limitations imposed by outdoor natural temperature differences, making testing difficult in summer when the indoor-outdoor temperature difference is small; and the need for frequent recording of ambient temperature during operation, resulting in a large workload for data post-processing.

[0004] To address the aforementioned issues, existing technologies have proposed various improved heating methods. For example, CN1900705A discloses a method of using a constant-power planar heat source to continuously heat the wall, combined with a heat flow meter and temperature sensor to calculate the heat transfer coefficient; CN102759543B discloses an on-site testing device comprising a heat spreader, a flexible electric heating coil layer, and an insulation material layer, which also uses an electric power regulator to control the heating power. These solutions confirm the technical feasibility of active heating combined with a heat flow meter measurement route, but there is still room for improvement in lateral heat loss control and rapid stabilization.

[0005] To address this issue, a rapid detection device and method for the heat transfer coefficient of building walls are proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a rapid detection device and method for the heat transfer coefficient of building walls, so as to solve the problems of insufficient control of lateral heat loss, long detection time, and accuracy affected by three-dimensional heat diffusion in the prior art, and enable the detection to quickly reach a steady state under active heating conditions and accurately measure the heat transfer coefficient of the wall.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a rapid detection device for the heat transfer coefficient of building walls, comprising: An electric heater is installed on the wall being tested. The electric heater has a main heating zone and a protective ring heating zone, which are arranged concentrically. A heat flow sensor assembly, comprising a plurality of heat flow sensors, wherein the heat flow sensors are mounted on the wall being measured and are located within the main heating zone; A temperature detection component, comprising a heating-side temperature sensor and a non-heating-side temperature sensor, wherein the heating-side temperature sensor is installed on the heated side of the wall being tested, and the non-heating-side temperature sensor is installed on the non-heated side of the wall being tested, and the heating-side temperature sensor is configured corresponding to the main heating zone. The controller is electrically connected to the electric heater, the heat flow sensor, and the high-precision temperature sensor, respectively. The controller integrates a data acquisition unit, a stability criterion unit, a calculation unit, an environmental correction unit, and an output unit.

[0008] Preferably, a thermally conductive silicone layer is fixedly connected to the wall being tested, the electric heater is installed on the thermally conductive silicone layer, and the heat flow sensor is installed on the thermally conductive silicone layer.

[0009] Preferably, a heat insulation groove is provided between the main heating zone and the retaining ring heating zone.

[0010] Preferably, the number of heat flow sensors is at least three, and all three heat flow sensors are located within the main heating zone.

[0011] Preferably, the heating-side temperature sensor and the non-heating-side temperature sensor are platinum resistance temperature sensors with a measurement accuracy of not less than ±0.05℃; the heat flow sensor has a sensitivity of not less than 10μV•㎡ / W and an accuracy of not less than ±5%.

[0012] Preferably, the electric heater is covered with a heat insulation layer.

[0013] A rapid method for detecting the heat transfer coefficient of building walls includes the following steps: Step 1: Select the test area, avoiding thermal bridges such as doors, windows, beams and columns. Clean the wall surface to ensure it is flat and dry. The effective size of the test area should be larger than the outer diameter of the electric heater, and the distance from adjacent thermal bridges should be no less than 500mm. Step 2: Attach the thermally conductive silicone layer to one side of the wall to be tested, attach the electric heater to the thermally conductive silicone layer, and confirm that there are no gaps after installation and fixation; distribute the heat flow sensor evenly within the projection range of the main heating area, and attach the two temperature sensors to both sides of the wall respectively; Step 3: First start the retaining ring heating zone, then start the main heating zone, preheat for 10-20 minutes, and start formal data collection after the heat flow sensor reading tends to rise and stabilize. Step 4: The controller receives the heat flux density q and the temperature difference ΔT between the two sides of the wall being tested 2 in real time, and determines whether the stability criterion has been reached. When the heat flux density and the temperature difference between the two sides of the wall being tested 2 reach relative stability within the set time window, the heat transfer coefficient of the wall is calculated according to the heat transfer coefficient formula K=q / ΔT, where ΔT is the temperature difference between the two sides of the wall, and the temperature difference ΔT = T1− T2, where T1 and T2 are the temperatures of the two sides of the wall being tested. Step 5: After reaching stability, take the average heat flux density q and temperature difference ΔT within the stability window, and calculate the heat transfer coefficient according to K=q / ΔT; at the same time, output the heat flux density time history curve, temperature time history curve and environmental parameter records. Step 6: Repeat the test in different locations, testing at least 3 different areas with a distance of no less than 500 mm between adjacent test points. Take the average heat transfer coefficient K of each point as the final result and calculate the coefficient of variation. If the coefficient of variation exceeds 10%, the number of test points should be increased.

[0014] Preferably, the principle for adjusting the power of the retaining ring heating zone in step three is to gradually increase the power of the retaining ring until the temperature difference between the outer side of the retaining ring and the edge temperature of the main heating zone does not exceed 0.5℃. This value is used as the set value for the retaining ring power and remains unchanged during subsequent testing.

[0015] Preferably, the data acquisition unit acquires heat flux density and temperature data in real time at a frequency of not less than 1 time / min; the stability criterion unit uses the heat flux density fluctuation range not exceeding ±5% and the temperature difference fluctuation range on both sides of the tested wall not exceeding ±0.2℃ as the stability criterion; after reaching stability, the calculation unit takes the average value of heat flux density and temperature difference within the stability window and substitutes it into the formula K=q / ΔT for calculation.

[0016] Preferably, the environmental correction unit is equipped with an ambient temperature sensor and a wind speed sensor to collect indoor and outdoor ambient temperatures and wind speed near the surface during the detection period. When the wind speed exceeds 0.5 m / s or the temperature difference between indoor and outdoor exceeds 2°C during the detection period, an alarm is issued to the operator and the environmental parameters are recorded in the detection report.

[0017] The present invention discloses the following technical effects: 1. By effectively suppressing lateral heat diffusion through the heating zone of the retaining ring, one-dimensional heat transfer is achieved, improving measurement accuracy. This invention incorporates a retaining ring heating zone concentric with the main heating zone and powered independently within the electric heater. During testing, the power of the retaining ring is independently adjusted to ensure its temperature matches the edge temperature of the main heating zone, thus forming a "thermal barrier" around the main heating zone and actively compensating for lateral heat loss. This structure forces the heat generated by the main heating zone to be transferred primarily along a direction perpendicular to the wall, making the heat flow within the projected area of ​​the main heating zone approach a one-dimensional heat transfer state. This avoids the measurement deviation of heat flow caused by three-dimensional heat diffusion in traditional heating methods, fundamentally improving the accuracy of calculating the heat transfer coefficient K.

[0018] 2. A heat flux sensor is used to directly measure the heat flux density through the wall, avoiding systematic errors in power estimation. Unlike existing technologies that indirectly estimate heat flux by detecting the total input power of the electric heater, this invention directly mounts a heat flux sensor within the orthographic projection range of the main heating zone of the wall being measured, actually collecting the effective heat flux density q passing through the wall. This approach avoids systematic errors in heat flux measurement caused by factors such as lateral heat dissipation, contact thermal resistance, and heat loss from the back of the heater. The heat flux measurement error depends only on the sensor's own accuracy (within ±5%), resulting in a clear and traceable measurement chain and more accurate and reliable measurement results.

[0019] 3. Active heating combined with stable criteria significantly shortens detection time. This invention employs a high-power circular planar electric heater to actively and constantly heat the wall, forcing the wall's temperature field to establish and stabilize rapidly. Combined with a stability criterion unit in the data processing module (heat flux density fluctuation not exceeding ±5% and temperature difference fluctuation not exceeding ±0.2℃ within 15 minutes), calculations are automatically triggered upon reaching stability. Compared to the traditional natural temperature difference heat flow meter method, which requires long-term monitoring of several hours to tens of hours, this invention can shorten the detection stabilization time to 40-90 minutes, significantly improving on-site testing efficiency and meeting the needs of rapid acceptance in building construction projects.

[0020] 4. Multi-point heat flux sampling and environmental parameter monitoring ensure the reliability and traceability of test results. This invention employs at least three heat flux sensors evenly distributed within the projected area of ​​the main heating zone, averaging the results to effectively reduce the impact of uneven wall material distribution or installation variations on the measurement results. Simultaneously, the data processing module integrates an environmental correction unit, equipped with independent ambient temperature and wind speed sensors, to monitor real-time changes in indoor and outdoor temperature differences and wind speed near the wall during testing. When environmental conditions exceed permissible limits (wind speed > 0.5 m / s or temperature difference > 2℃), an alert is issued to the operator, and the environmental parameters are recorded in the test report, facilitating quality assessment and post-test traceability of the test results.

[0021] 5. The structure is reasonably designed and easy to operate on site. The device of this invention uses a circular planar electric heater. The heating surface is provided with a thermally conductive silicone layer to reduce contact thermal resistance, and the non-heated surface and sides are covered with a heat insulation layer to reduce back heat dissipation. The overall structure is compact and lightweight. It can be quickly fixed to the wall with a suction cup, and is easy to assemble and disassemble. It is suitable for rapid deployment and testing in various scenarios on construction sites.

[0022] This invention suppresses lateral heat diffusion through the heating zone of the retaining ring, and directly measures the heat flux density through the wall using a heat flux sensor, which significantly shortens the detection time and improves the accuracy of heat transfer coefficient calculation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the rapid detection device for the heat transfer coefficient of building walls according to the present invention. Figure 2 This is a top view of the detection device of the present invention; Figure 3 This is a flowchart of the detection method of the present invention; The components include: 1. Main heating zone; 2. Protective ring heating zone; 3. Insulation groove; 4. Thermal insulation layer; 5. Thermally conductive silicone layer; 6. Heat flow sensor; 7. Heating side temperature sensor; 8. Non-heating side temperature sensor; 9. Controller; 10. Measuring wall; 11. Ambient temperature sensor; 12. Ambient temperature sensor; 13. Electric heater. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1 Reference Figure 1-3 This invention provides a rapid detection device for the heat transfer coefficient of a wall structure, comprising: Electric heater 13 is installed on the wall 10 being tested. Electric heater 13 has a main heating zone 1 and a protective ring heating zone 2, which are arranged concentrically. The heat flow sensor assembly includes several heat flow sensors 6, which are mounted on the wall 10 being measured and are located within the main heating zone 1. The temperature detection component includes a heating-side temperature sensor 7 and a non-heating-side temperature sensor 8. The heating-side temperature sensor 7 is installed on the heated side of the wall 10 being tested, and the non-heating-side temperature sensor 8 is installed on the non-heated side of the wall 10 being tested. The heating-side temperature sensor 7 is set to correspond to the main heating zone 1. The controller 9 is electrically connected to the electric heater 13, the heat flow sensor 6, and the high-precision temperature sensor 7. The controller 9 integrates a data acquisition unit, a stability criterion unit, a calculation unit, an environmental correction unit, and an output unit.

[0028] In this device, the electric heater 13 is circular in shape, and its flat end can completely cover the wall 10 being tested. It is made of high thermal conductivity aluminum alloy or copper-based substrate. The power range of the main heating zone 1 is 300–1200W, the diameter of the heating surface is 200–400mm, and the uniformity error of the heating surface does not exceed ±5%. The width of the retaining ring heating zone 2 is 50–100mm, and the power of the retaining ring is independently adjustable. Its function is to make the temperature of the retaining ring area and the edge temperature of the main heating zone tend to be consistent, thereby suppressing the lateral heat diffusion of the main heating zone and making the heat flow through the positive projection area of ​​the main heating zone close to the one-dimensional heat transfer state.

[0029] The heating side temperature sensor 7 and the non-heating side temperature sensor 8 have a measurement accuracy of not less than ±0.05℃. The heating side temperature sensor 7 and the non-heating side temperature sensor 8 are respectively attached to the heating side and the non-heating side surface of the wall being measured. The installation position is located at the center of the orthographic projection of the main heating zone. The wall surface temperatures T1 and T2 on both sides of the wall being measured are ΔT = T1− T2.

[0030] The controller 9 uses an STM32 embedded processor with a data acquisition frequency of 1 time / min; an LCD color screen that displays the q time history curve, ΔT time history curve, K value, and environmental parameters in real time; built-in storage can record no less than 200 sets of detection data; and supports USB export.

[0031] The scheme was further optimized by fixing a thermally conductive silicone layer 5 to the wall 10 under test, installing an electric heater 13 on the thermally conductive silicone layer 5, and installing a heat flow sensor 6 on the thermally conductive silicone layer 5.

[0032] The thickness of the thermally conductive silicone layer 5 ranges from 1 to 3 mm, and the contact thermal resistance is not higher than 0.005 m²•K / W.

[0033] To further optimize the design, a heat insulation groove 3 is installed between the main heating zone 1 and the protective ring heating zone 2.

[0034] The function of the heat insulation groove 3 is to reduce mutual thermal crosstalk. The heat insulation groove 3 is about 5 mm wide and 3 mm deep, and is filled with polytetrafluoroethylene.

[0035] To further optimize the design, the number of heat flow sensors 6 is at least three, and all three heat flow sensors 6 are located within the main heating zone 1.

[0036] Three heat flux sensors 6 are evenly distributed within the orthographic projection range of the main heating zone, with a sensitivity of not less than 10 μV•㎡ / W and a measurement accuracy of not less than ±5%. The thickness of the heat flux sensors 6 does not exceed 0.5 mm to reduce the influence on the temperature field. The average value of the heat flux density at multiple points is taken as the input quantity q (W / ㎡) for calculating the heat transfer coefficient.

[0037] Further optimization of the scheme: the heating side temperature sensor 7 and the non-heating side temperature sensor 8 adopt platinum resistance temperature sensors with a measurement accuracy of not less than ±0.05℃; the heat flow sensor 6 has a sensitivity of not less than 10μV•㎡ / W and an accuracy of not less than ±5%.

[0038] The high-precision temperature sensor 7 is a PT1000 platinum resistance temperature sensor with a measurement accuracy of ±0.05℃.

[0039] The design was further optimized by covering the electric heater 13 with a heat insulation layer 4.

[0040] The thickness of the thermal insulation layer 4 is not less than 20mm, and the thermal conductivity of the thermal insulation layer 4 is not higher than 0.05W / (m•K), reducing heat dissipation from the back and sides.

[0041] A rapid method for detecting the heat transfer coefficient of building walls includes the following steps: Step 1: Select the test area, avoiding thermal bridges such as doors, windows, beams and columns. Clean the wall surface to ensure it is flat and dry. The effective size of the test area should be larger than the outer diameter of the electric heater (13mm), and the distance from adjacent thermal bridges should be no less than 500mm. Step 2: Attach the thermally conductive silicone layer 5 to one side of the wall 10 to be tested, attach the electric heater 13 to the thermally conductive silicone layer 5, and confirm that there are no gaps after installation and fixation; distribute the heat flow sensor 6 evenly within the projection range of the main heating area 1, and attach the two temperature sensors to both sides of the wall respectively. Step 3: First start the retaining ring heating zone 2, then start the main heating zone 1, preheat for 10-20 minutes, and start formal data collection after the reading of the heat flow sensor 6 tends to rise and stabilize. Step 4: The controller 9 receives the heat flux density q and the temperature ΔT on both sides of the wall 10 being tested in real time, and determines whether the stability criterion has been reached. When the heat flux density and the temperature difference between the two sides of the wall 10 being tested reach relative stability within the set time window, the heat transfer coefficient of the wall is calculated according to the heat transfer coefficient formula K=q / ΔT, where ΔT is the temperature difference between the two sides of the wall, and the temperature difference ΔT=T1-T2, where T1 and T2 are the temperatures of the two sides of the wall being tested. Step 5: After reaching stability, take the average heat flux density q and temperature difference ΔT within the stability window, and calculate the heat transfer coefficient according to K=q / ΔT; at the same time, output the heat flux density time history curve, temperature time history curve and environmental parameter records. Step 6: Repeat the test in different locations, testing at least 3 different areas with a distance of no less than 500 mm between adjacent test points. Take the average heat transfer coefficient K of each point as the final result and calculate the coefficient of variation. If the coefficient of variation exceeds 10%, the number of test points should be increased.

[0042] Further optimize the scheme. In step three, the power adjustment principle for the retaining ring heating zone 2 is as follows: gradually increase the power of the retaining ring until the temperature difference between the outer side of the retaining ring and the edge temperature of the main heating zone 1 does not exceed 0.5℃. This value is used as the set value for the retaining ring power and remains unchanged during subsequent testing.

[0043] The scheme was further optimized. The data acquisition unit collected heat flux density and temperature data in real time at a frequency of no less than once per minute. The stability criterion unit used the fluctuation range of heat flux density within 15 minutes not exceeding ±5% and the fluctuation range of temperature difference between the two sides of the tested wall 10 not exceeding ±0.2℃ as the stability criteria. After reaching stability, the calculation unit took the average value of heat flux density and temperature difference within the stability window and substituted it into the formula K=q / ΔT for calculation.

[0044] The scheme has been further optimized. The environmental correction unit is equipped with an ambient temperature sensor and a wind speed sensor to collect indoor and outdoor ambient temperatures and wind speed near the surface during the test. When the wind speed exceeds 0.5 m / s or the temperature difference between indoor and outdoor exceeds 2°C during the test, an alarm is issued to the operator and the environmental parameters are recorded in the test report.

[0045] Example 2 Reference Figure 1-3 A rapid testing device for the heat transfer coefficient of building walls, with the following specific parameters: High-power circular planar electric heater: Main heating zone: heating surface diameter 300mm, power 600W, aluminum alloy base material, heating surface uniformity error ≤±5%; Heating zone of retaining ring: 70mm wide, independently powered, maximum power 200W, adjustable; Insulation groove: 5mm wide, 3mm deep, filled with polytetrafluoroethylene; Back side insulation layer: 25mm thick rock wool, with a thermal conductivity of approximately 0.04W / (m•K); Bonding surface: 2mm thermally conductive silicone layer, contact thermal resistance approximately 0.003㎡•K / W.

[0046] Heat flow sensor assembly: Sensor model: Thin-film thermopile heat flux sensor, sensitivity approximately 60 μV•㎡ / W; Quantity: 3 units, evenly distributed within the orthographic projection area of ​​the main heating zone (arranged at equal angles, 100mm from the center). Thickness: 0.3mm, its effect on the temperature field is negligible.

[0047] Temperature detection component: Two PT1000 platinum resistance temperature sensors, with a measurement accuracy of ±0.05℃, are attached to both sides of the wall. One independent ambient temperature sensor (PT100) is installed 500mm from the wall. Wind speed sensor: hot wire anemometer, range 0–5 m / s, accuracy ±0.1 m / s.

[0048] Data processing module: STM32 embedded processor, sampling frequency 1 time / min; The LCD color screen displays the q-time history curve, ΔT-time history curve, K value, and environmental parameters in real time. Built-in storage can record no fewer than 200 sets of test data; USB export is supported.

[0049] Example 3 Reference Figure 1-3 A rapid method for detecting the heat transfer coefficient of building walls, comprising the following steps: Step 1: Preprocessing of the detection area Select the central area of ​​the north wall, avoiding window openings and beams, with a test area size of 600mm × 600mm, and a distance of more than 500mm from adjacent thermal bridges. Clean the wall surface, smooth any protrusions with fine sandpaper, and ensure the surface is flat and dry so that it can fully adhere to the thermally conductive silicone layer.

[0050] Step 2: Install the device Attach the thermally conductive silicone side of the electric heater to the inner side of the wall to be tested, and secure it with a suction cup, ensuring a seamless fit. Distribute the three heat flow sensors evenly within the projected area of ​​the main heating zone and secure them with thermally conductive adhesive. Attach the heating-side temperature sensor to the inner surface of the wall (located at the center of the main heating zone's projection), and attach the non-heating-side temperature sensor to the corresponding position on the outer surface of the wall. Install the ambient temperature sensor and wind speed sensor approximately 500mm from the wall.

[0051] Step 3: Preheating Start the retaining ring heating zone and set the initial power to 100W. Start the main heating zone and set the power to 600W. Preheat for 15 minutes, and simultaneously observe the temperature difference between the outer edge of the retaining ring and the edge of the main heating zone. Gradually adjust the retaining ring power so that the temperature difference between the two does not exceed 0.5℃. Set the retaining ring power to 150W and keep it unchanged.

[0052] Step 4: Data Acquisition and Stability Assessment The data processing module began formal data acquisition at a frequency of 1 time / min. After 35 minutes of acquisition, the average heat flux density stabilized at approximately 37.5 W / m², with a fluctuation of ±2.5% over 15 minutes; the temperature difference between the two sides of the wall stabilized at approximately 18.0℃, with a fluctuation of ±0.1℃, meeting the stability criterion and triggering calculation.

[0053] Step 5: Calculation of heat transfer coefficient The mean within the stable window is taken as: q = 37.5 W / m², ΔT = 18.0 K.

[0054] K=q / ΔT=37.5 / 18.0≈2.08W / (㎡·K) This value is consistent with the typical heat transfer coefficient of similar external insulation composite walls (0.3–2.5 W / (㎡•K)), and the result is reasonable.

[0055] Step 6: Multi-point detection The experiment was repeated in two other areas on the north wall (600mm apart), yielding K values ​​of 2.11 W / (㎡•K) and 2.06 W / (㎡•K). The mean of the three values ​​was 2.08 W / (㎡•K), with a coefficient of variation of approximately 1.2%, which meets the requirements.

[0056] Comparative verification: The same wall was tested using the traditional heat flow meter method (natural temperature difference conditions, continuous for 72 hours), and the result was K=2.10W / (㎡•K), which differs from the measurement result of this device by 0.02W / (㎡•K) (deviation of about 1.0%), meeting the accuracy requirements for project acceptance.

[0057] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to 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 a limitation of this invention.

[0058] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A rapid detection device for the heat transfer coefficient of building walls, characterized in that, include: An electric heater (13) is installed on the wall (10) being tested. The electric heater (13) has a main heating zone (1) and a protective ring heating zone (2) inside. The main heating zone (1) and the protective ring heating zone (2) are arranged concentrically. A heat flow sensor assembly, comprising a plurality of heat flow sensors (6), wherein the heat flow sensors (6) are mounted on the wall to be measured (10) and are located within the main heating zone (1); Temperature detection component, the temperature detection component includes a heating side temperature sensor (7) and a non-heating side temperature sensor (8), the heating side temperature sensor (7) is installed on the heated side of the wall (10) under test, the non-heating side temperature sensor (8) is installed on the non-heated side of the wall (10) under test, the heating side temperature sensor (7) is set corresponding to the main heating area (1); The controller (9) is electrically connected to the electric heater (13), the heat flow sensor (6), and the high-precision temperature sensor respectively. The controller (9) integrates a data acquisition unit, a stability criterion unit, a calculation unit, an environmental correction unit, and an output unit.

2. The rapid detection device for the heat transfer coefficient of building walls according to claim 1, characterized in that: A thermally conductive silicone layer (5) is fixedly connected to the wall (10) under test. The electric heater (13) is installed on the thermally conductive silicone layer (5). The heat flow sensor (6) is installed on the thermally conductive silicone layer (5).

3. The rapid detection device for the heat transfer coefficient of building walls according to claim 1, characterized in that: A heat insulation groove (3) is provided between the main heating zone (1) and the protective ring heating zone (2).

4. The rapid detection device for the heat transfer coefficient of building walls according to claim 1, characterized in that: The number of heat flow sensors (6) is at least three, and all three heat flow sensors (6) are located in the main heating zone (1).

5. The rapid detection device for the heat transfer coefficient of building walls according to claim 1, characterized in that: The heating-side temperature sensor (7) and the non-heating-side temperature sensor (8) are platinum resistance temperature sensors with a measurement accuracy of not less than ±0.05℃; the heat flow sensor (6) has a sensitivity of not less than 10μV•㎡ / W and an accuracy of not less than ±5%.

6. The rapid detection device for the heat transfer coefficient of building walls according to claim 1, characterized in that: The electric heater (13) is covered with a heat insulation layer (4).

7. A method for rapid detection of the heat transfer coefficient of building walls, based on the rapid detection device for the heat transfer coefficient of building walls as described in any one of claims 1-6, characterized in that, The steps include the following: Step 1: Select the test area, avoiding thermal bridges such as doors, windows, beams and columns. Clean the wall surface to ensure it is flat and dry. The effective size of the test area should be larger than the outer diameter of the electric heater (13) and the distance from the adjacent thermal bridge should not be less than 500mm. Step 2: Place the thermally conductive silicone layer (5) on one side of the wall (10) to be tested, attach the electric heater (13) to the thermally conductive silicone layer (5), and confirm that there are no gaps after installation and fixing; distribute the heat flow sensor (6) evenly within the projection range of the main heating area (1), and attach the two temperature sensors to the two sides of the wall respectively; Step 3: First start the retaining ring heating zone (2), then start the main heating zone (1), preheat for 10–20 minutes, and start formal data collection after the heat flow sensor (6) reading tends to rise and stabilize; Step 4: The controller (9) receives the heat flux density q and the temperature difference ΔT between the two sides of the wall (10) being tested in real time, and determines whether the stability criterion has been reached. When the heat flux density and the temperature difference between the two sides of the wall (10) being tested reach relative stability within the set time window, the heat transfer coefficient of the wall is calculated according to the heat transfer coefficient formula K=q / ΔT, where ΔT is the temperature difference between the two sides of the wall, and the temperature difference ΔT = T1− T2, where T1 and T2 are the temperatures of the two sides of the wall being tested. Step 5: After reaching stability, take the average heat flux density q and temperature difference ΔT within the stability window, and calculate the heat transfer coefficient according to K=q / ΔT; at the same time, output the heat flux density time history curve, temperature time history curve and environmental parameter records. Step 6: Repeat the test in different locations, testing at least 3 different areas with a distance of no less than 500mm between adjacent test points. Take the average heat transfer coefficient K of each point as the final result.

8. The method for rapid detection of the heat transfer coefficient of building walls according to claim 7, characterized in that: The principle for adjusting the power of the retaining ring heating zone (2) in step three is to gradually increase the power of the retaining ring until the temperature difference between the outer side of the retaining ring and the edge temperature of the main heating zone (1) does not exceed 0.5℃. This is used as the set value of the retaining ring power, which remains unchanged in subsequent testing.

9. A method for rapid detection of the heat transfer coefficient of building walls according to claim 7, characterized in that: The data acquisition unit collects heat flux density and temperature data in real time at a frequency of not less than 1 time / min; the stability criterion unit uses the fluctuation range of heat flux density within 15 minutes not exceeding ±5% and the fluctuation range of temperature difference between the two sides of the tested wall (10) not exceeding ±0.2℃ as the stability criterion; after reaching stability, the calculation unit takes the average value of heat flux density and temperature difference within the stability window and substitutes it into the formula K=q / ΔT for calculation.

10. A method for rapid detection of the heat transfer coefficient of building walls according to claim 7, characterized in that: The environmental correction unit is equipped with an ambient temperature sensor (11) and a wind speed sensor (12) to collect indoor and outdoor ambient temperatures and wind speed near the surface during the detection period. When the wind speed exceeds 0.5 m / s or the temperature difference between indoor and outdoor exceeds 2°C during the detection period, an alarm is issued to the operator and the environmental parameters are recorded in the detection report.

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