CN114486997B - Phase-change composite wall thermal performance testing device and method - Google Patents

Phase-change composite wall thermal performance testing device and method Download PDF

Info

Publication number
CN114486997B
CN114486997B CN202011162519.1A CN202011162519A CN114486997B CN 114486997 B CN114486997 B CN 114486997B CN 202011162519 A CN202011162519 A CN 202011162519A CN 114486997 B CN114486997 B CN 114486997B
Authority
CN
China
Prior art keywords
wall
heat
tested
temperature
wall body
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202011162519.1A
Other languages
Chinese (zh)
Other versions
CN114486997A (en
Inventor
张源
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yangzhou University
Original Assignee
Yangzhou University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yangzhou University filed Critical Yangzhou University
Priority to CN202011162519.1A priority Critical patent/CN114486997B/en
Publication of CN114486997A publication Critical patent/CN114486997A/en
Application granted granted Critical
Publication of CN114486997B publication Critical patent/CN114486997B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/18—Investigating or analyzing materials by the use of thermal means by investigating thermal conductivity
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/02—Investigating or analyzing materials by the use of thermal means by investigating changes of state or changes of phase; by investigating sintering
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A30/00—Adapting or protecting infrastructure or their operation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/90—Passive houses; Double facade technology

Abstract

The invention discloses a phase-change composite wall thermal performance testing device and a method thereof: comprises an angle steel frame for constructing a cube structure; square heat-insulating wallboards are placed on the upper surface and the lower surface of the frame, wall frames to be tested are placed on the four sides of the frame, and the wall to be tested is placed in the central hole of the frame; an incandescent lamp positioned at the central position in the box body is used as a heat source of the wall body to be tested; sticking a thermocouple temperature measurement at a specific thickness position on the surface and the inside of a wall to be measured, and sticking a heat flow meter on the outer side surface of a box body of the wall to be measured to obtain the heat flow density of the wall; collecting data by a data collector connected with a sensor; after the test results are arranged and calculated, the unsteady thermal performance index values such as attenuation times, delay times and the like of the wall body and the steady thermal performance index values such as thermal resistance, heat transfer coefficients and the like can be obtained. The method has the advantages of simplicity in operation, wide application range, stable test conditions, high test efficiency, strong comparability of test results and the like.

Description

Phase-change composite wall thermal performance testing device and method
Technical Field
The invention belongs to the technical field of building thermal performance testing, and particularly relates to a device and a method for testing thermal performance of a phase-change composite wall body.
Background
Phase Change Materials (PCM) refer to a class of substances that change phase with temperature changes and undergo absorption and release of latent heat. During the phase change, the PCM absorbs or releases a large amount of latent heat, while its own temperature is unchanged or changes little. With the gradual penetration of the research on the thermal performance and the application of the PCM, the building wall body composited with the PCM is increasingly entering the work and the life of people. The PCM is compounded in the building wall, the heat accumulation and release characteristics of the PCM are reasonably utilized, and the purposes of reducing indoor heat flow and stabilizing indoor temperature amplitude can be achieved, so that the building energy-saving level and indoor heat comfort level are remarkably improved. Thus, there is a need for accurate and efficient acquisition of thermal properties of composite PCM building walls.
Currently, the thermal performance of the phase-change composite wall is mainly obtained by two methods, namely numerical simulation calculation and thermal performance test. Because the mathematical model used in the numerical simulation calculation has deviation when describing the actual heat transfer process, it is difficult to obtain a more accurate result. Therefore, the thermal performance test of the phase-change composite wall body is increasingly applied to scientific research and engineering practice.
However, thermal performance testing of phase change composite walls is not perfect. When the thermal performance of the entity wall is tested, the test result can not accurately reflect the thermal performance of the tested wall under the target thermal boundary condition due to the influence of factors such as outdoor weather change, outdoor atypical thermal conditions, improper test method and operation and the like. Meanwhile, some testing methods can only test single-sided walls, or can only test building wallboards with smaller thickness, or can not ensure that a plurality of walls are under identical testing conditions, can not ensure the consistency of a temperature field in a wall (9) to be tested and an actual building (such as the influence of lateral heat conduction), and the like, and the problems related to the application range, the testing precision, the testing efficiency and the like of the testing methods can also lead the testing result to deviate from a true value. In addition, no standard method or basic principle is given to the thermal performance test of the phase-change composite wall body in the relevant building energy-saving standard in China.
Chinese patent 201510363741.0 and 201520449944.7 disclose a testing device for phase change thermal insulation effect of building wall and a using method thereof, which are characterized in that: the device and the method can be used for testing the heat preservation and insulation effect of the phase change heat preservation system of the building wall body relative to the heat preservation system of the conventional building wall body. But this technique is subject to outdoor weather changes and can only be used to test single-sided, low-thickness phase change building panels at the same time. Chinese patent 201520976032.5 discloses a device for testing the overall heat insulation effect of a phase-change wall body, and realizes the heat insulation contrast effect of the phase-change wall body and a common wall body in four directions by one-time test. However, the technology is also limited by outdoor weather conditions, can not freely and accurately set indoor and outdoor target thermal environment conditions for the wall to be tested, and can only be used for testing the heat preservation and insulation effects of a single same phase-change wall and a common wall. Chinese patent 201811560097.6 discloses a testing device and method for building phase-change wallboard. The method is characterized in that the method can be used for testing the effective heat conductivity, equivalent specific heat capacity and other thermophysical parameters of the phase-change wallboard of the building, and provides a way and a method for further evaluating the thermodynamic performance of the phase-change enclosure structure. The technology is limited by the ability to test only small, single sided phase change wallboard simultaneously. Chinese patent 201920006763.5 discloses a phase-change wall body heat preservation effect testing device. Also, the technology can only test and compare single-sided phase change walls with single-sided common walls at the same time.
Disclosure of Invention
The invention aims to establish a phase-change composite wall thermal performance testing method to simplify operation, expand application surface, improve stability and testing efficiency of testing conditions and comparability of testing results.
In order to solve the technical problems, the invention can be realized by the following ideas: 1) Comprises an angle steel frame for constructing a cube structure; 2) Square heat-insulating wallboards are placed on the upper surface and the lower surface of the frame, wall frames to be tested are placed on the four sides of the frame, and the wall to be tested is placed in the central hole of the frame; 3) An incandescent lamp positioned at the central position in the box body is used as a heat source of the wall body to be tested; 4) Sticking a thermocouple temperature measurement at specific thickness positions on the surface and the inside of a wall to be measured, and sticking a heat flow meter on the outer surface of the box body of the wall to be measured by using mechanical butter to obtain the heat flow density of the wall; 5) Collecting data by a data collector connected with a sensor; 6) After the test results are arranged and calculated, the unsteady thermal performance index values such as attenuation times, delay times and the like of the wall body and the steady thermal performance index values such as thermal resistance, heat transfer coefficients and the like can be obtained.
The invention adopts the following specific technical scheme:
the phase-change composite wall thermal performance testing device is characterized by comprising:
the heat-insulating wall comprises a fan (1), a heat source (2), a thermocouple (3), a heat-insulating wall board (4), a wall body frame (5), square holes (6), a structural frame (7), a heat-insulating material (8), a wall body (9) to be tested and a bracket (10);
the structural frame (7) is formed by welding angle steel frames and is used for supporting foot frames;
the heat preservation wallboards (4) with corresponding sizes are arranged in the angle steel frames above and below the structural frame (7); wall frames (5) with corresponding sizes are placed in angle steel grooves around the structural frame (7), heat insulation materials are filled in the frames, each wall frame (5) is detachably fastened by 2 binding bands respectively, and each binding band is tied on an upper bracket (10) and a lower bracket (10) which correspond to each other respectively; the upper and lower heat-insulating wallboards (4) and the surrounding wall frames (5) form a test box body; the outer surface and the inner surface of the wall body (9) to be tested in actual use face the inner environment space and the outer environment space of the test box body respectively in the test box body;
a square hole (6) is arranged at the center of the wall body frame (5); a small wall body (9) to be measured is built in a central hole (6) of the wall body frame (5), and the size of the central hole (6) is larger than that of the wall body (9) to be measured; the thermal insulation material (8) is filled between the peripheral surface of the wall body (9) to be tested and the inner surface of the central hole (6); the heat sources (2) of the wall body (9) to be tested are four incandescent lamps positioned at the central position inside the test box body, and the four incandescent lamps are respectively aligned to the central areas of the four wall bodies (9) to be tested; the on and off of the heat source (2) are controlled by a timing controller, the brightness is controlled by a current magnitude controller, and the simulation of the outdoor thermal boundary conditions of day and night can be realized through debugging; and the indoor thermal boundary conditions are controlled by an air conditioner in the laboratory;
fans (1) are respectively arranged at four corners of the test box body to ensure air flow and thermal uniformity in the test box body; the middle part of the heat-insulating wallboard (4) at the upper end of the test box body is provided with a hole, and a fan (1) is embedded in the hole to promote the air flow between the inner side and the outer side of the test box body, and the purpose of cooling the environment at the inner side of the test box body is achieved; if the air temperature outside the test box is insufficient to cool the inside of the test box, a small air conditioning fan is connected with the middle opening through a ventilation pipeline so as to strengthen the cooling effect of the air environment in the test box.
The side length of the structural frame (7) is in the range of 1.0 m-1.5 m.
The outer layer materials of the heat-insulating wallboard (4) and the wall frame (5) are wood materials with the thickness ranging from 0.008m to 0.015 m; the heat-insulating wallboard (4) contains a heat-insulating material layer with the thickness of 0.08 m-0.12 m, and has a heat insulation effect between the inner side and the outer side of the test box body; the wall frame (5) is set to be 0.2-0.4 m thick according to the thickness of the wall to be measured; the heat insulation material is any one of conventional heat insulation material foamed polyethylene, foamed polystyrene and foamed polyurethane.
The heat source (2) selects an incandescent lamp with the power of 50W-300W according to actual needs.
The phase-change composite wall thermal performance testing method is characterized by comprising the following steps of:
step one, taking down the wall frame from the test box body
Releasing the binding belt, and respectively taking down the four wall frames (5) of the test box body to load the wall to be tested; the wall body frame (5) is filled with heat insulation materials, so that lateral heat conduction of the wall body (9) to be tested in the testing process is prevented;
step two, building the wall to be tested to obtain an intermediate
A layer of heat preservation material layer is respectively padded at the lower boundaries of the central holes (6) of the four wall frames (5) of the test box body, and then a wall (9) to be tested is respectively built in the four central holes (6); if the number of the built walls (9) to be tested is smaller than 4, filling the central holes (6) of the rest wall frames (5) with heat insulation materials; if the built wall body (9) to be tested is of a multi-layer structure, the bonding mode among all layers is concrete or mortar, or mechanical butter is uniformly smeared on the contact surfaces among all layers of the wall body so as to ensure good thermal contact among the surfaces;
obtaining an intermediate after the step two is completed, wherein the intermediate comprises four wall frames (5);
filling the central hole
In order to better prevent lateral heat conduction of the wall body (9) to be measured and enable the size selection of the wall body (9) to be measured to be more elastic, heat preservation materials are filled between the inner surface of the central hole (6) of the wall body frame (5) and the outer surfaces around the wall body (9) to be measured; compacting the heat insulation material (8), spraying and filling gaps by using heat insulation foam, and enabling the inner surfaces of the wall body (9) to be tested, the heat insulation material and the central hole (6) to be in a close contact state so as to ensure that no air convection heat exchange exists between the inside of the wall body (9) to be tested and the outside;
step four, setting a temperature and heat flow sensor
Uniformly sticking thermocouples (3) on the outer surface of each wall (9) to be measured in the thickness direction by using aluminum foil adhesive tapes so as to obtain the time-by-time change condition of the wall temperature; all the measuring heads of the thermocouples (3) are stuck or wrapped by aluminum foil adhesive tapes so as to prevent the deviation of the measured temperature value caused by the influence of heat radiation of the surrounding environment; a plurality of thermocouples (3) are arranged in the inner side space and the outer side space of the test box body to obtain the temperature time-by-time change condition of the ambient air inside and outside the test box body; sticking a heat flow meter on the part of the wall body (9) to be tested, which is positioned on the outer surface of the test box, by using mechanical butter so as to obtain the change condition of the heat flow density passing through the wall body (9) to be tested;
according to the requirements of experimental tests, uniformly sticking thermocouples (3) at different thickness positions inside the wall body (9) to be tested in the second step to obtain the temperature gradual change condition at the specific thickness;
step five, setting and debugging a data acquisition system
Connecting the wiring terminals of all thermocouples and the heat flow meter with a data acquisition instrument, and debugging the data acquisition system; all temperature and heat flow signals are collected by a data acquisition instrument and transmitted to a computer in real time for the arrangement and analysis of test results, and acquisition software of the corresponding data acquisition instrument is installed on the computer;
step six, installing a wall frame
The intermediate body is arranged in an angle steel frame of the test box body, four wall frames (5) in the intermediate body are respectively tightly bound with the surrounding four sides of the angle steel frame by two binding bands, and each binding band is tied on an upper bracket (10) and a lower bracket (10) corresponding to the intermediate body;
step seven, turning on all fans
Step eight, debugging the heat source
Starting an air conditioner, and adjusting the external environment temperature of the test box body to simulate the indoor temperature of the actual use environment of the wall body to be tested; further, the outdoor temperature of the actual use environment of the wall to be tested is simulated by adjusting the environmental temperature in the test box body through a fan and a heat source;
if the thermal performance is unsteady state thermal performance test, in order to simulate the actual day and night outdoor thermal boundary conditions of the wall to be tested, the timing controller and the current magnitude controller are debugged and controlled according to the acquired data conditions, so that the switching time and the power magnitude of the heat source (2) in each period are determined, and the outdoor thermal conditions required by the experiment are manufactured by utilizing the heat source (2);
if the thermal performance is tested in a steady state, the heat source (2) is always kept in an open state in the test process, so that the surface temperature of the wall (9) to be tested in the test box body is obviously higher than the peripheral test environment temperature;
step nine, experimental testing the thermal performance of the wall to be tested, and collecting test data
Step ten, sorting and calculating the test data
Sorting data acquired by a data acquisition instrument; calculating attenuation times and delay time values of the wall body by using the unsteady state test results; calculating to obtain a thermal resistance value of the wall body by using a steady-state test result;
the attenuation multiple is the ratio of the temperature amplitude of the inner side surface of the box of the wall body (9) to be detected to the temperature amplitude of the outer side surface of the box;
the delay time is the difference between the peak time of the surface temperature of the outer side of the box of the wall body (9) to be detected and the peak time of the surface temperature of the inner side of the box, and the unit is h;
the thermal resistance value is the ratio of the temperature difference at two ends of the wall body (9) to be measured to the heat flow density passing through the wall body, and the unit is m 2 ·K·W -1 。
Compared with the prior art, the invention has the following advantages and beneficial effects.
a. The testing method provided by the invention is simple to operate, has wide application range, and can be used for testing the thermal performance level of any conventional wall or wallboard structure containing or not containing PCM;
b. according to the eighth step, the method can accurately simulate any indoor and outdoor heat boundary conditions by controlling the laboratory air conditioner and the heat source in the test box body, and has wide application range;
c. the method can accurately control the heat source in the laboratory air conditioner and the test box body, thereby ensuring the stability of the test conditions and being not influenced by any outdoor climate change;
d. according to the setting of the phase-change composite wall thermal performance testing device and the filling measures of the central hole of the wall frame in the third step, the method can effectively prevent the lateral heat conduction of the wall to be tested, ensure the stability of the temperature field inside the tested wall and the one-dimensional heat transfer process of the wall, and enable the testing result to be more accurate;
e. in the method, the test box body is provided with four wall frames, so that the test box body has higher test efficiency, and four walls can be tested simultaneously;
f. as shown in the eighth step, each wall to be tested in the method is under the influence of the identical cold and heat sources, so that a plurality of walls to be tested are ensured to be under the identical test condition, and the method has strong comparability of test results.
Drawings
FIG. 1 is a schematic diagram of the basic structure of a thermal performance test stand for a phase-change composite wall body;
FIG. 2 is a schematic diagram of a wall to be tested for thermal properties and a frame of the phase change composite wall according to the present invention;
FIG. 3 is a schematic illustration of a wall to be tested, a conventional hollow block wall, in accordance with an embodiment of the present invention;
FIG. 4 is a block diagram of a wall to be tested, a conventional hollow block wall filled with a layer of PCM, in an embodiment of the invention;
FIG. 5 is a graph showing the temperature change of the wall surface to be measured under the condition of temperature zone 1 according to the embodiment of the present invention;
FIG. 6 is a graph showing the temperature decay times of the wall under test under the temperature zone 1 condition in an embodiment of the present invention;
FIG. 7 shows the heat flux density variation of the wall under test in the temperature zone 1 condition according to the embodiment of the present invention;
FIG. 8 is a graph showing the thermal resistance of a wall to be tested according to an embodiment of the present invention;
FIG. 9 is a graph showing the temperature change of the wall surface to be measured under the condition of temperature zone 2 according to the embodiment of the present invention;
FIG. 10 is a graph showing the temperature decay times of the wall under test under the temperature zone 2 condition in an embodiment of the present invention;
fig. 11 shows the heat flux density variation of the wall to be tested under the condition of the temperature zone 2 according to the embodiment of the present invention.
Detailed Description
The technical scheme of the invention is further described in detail below with reference to the attached drawings and specific embodiments.
Example 1
By adopting the testing method, the hollow block wall filled with the PCM is tested under the unsteady state and steady state thermal boundary conditions.
The PCM used is a paraffin-based material, commercially known as PX-27. The phase transition temperature of the PCM is 25.4-27.7 ℃, and the phase transition latent heat is 93.16 kJ.kg -1 。
The wall 9 to be tested is shown in fig. 3 and 4. Fig. 3 is a conventional hollow block wall, and fig. 4 is a wall in which PCM is filled into a hole at the outside of a box of the wall of fig. 3.
The test device used is arranged entirely in accordance with claim 1.
The test procedure is as follows:
step one, taking down the wall frame 5;
step two, building a wall body 9 sample to be tested;
a heat preservation material layer is respectively padded at the lower boundary of the central holes 6 of two wall frames 5 of the test box body, and a small wall 9 sample to be tested is respectively built in the central holes 6 of the two wall frames 5; filling the central holes 6 of the remaining two wall frames 5 with a heat insulating material; uniformly sticking thermocouples 3 at two different thickness positions inside the wall 9 to be measured according to the requirement to obtain the temperature gradual change condition of a specific thickness position; uniformly smearing a proper amount of mechanical butter on the contact surfaces among all layers of the wall body to ensure good thermal contact among the surfaces;
filling holes;
filling a sufficient amount of heat insulation material 8 between the peripheral surface of the wall 9 to be tested and the surface of the central hole 6; compacting the heat insulation material 8, spraying heat insulation foam, filling gaps, and ensuring that no air convection heat exchange exists between the inside of the wall 9 to be tested and the outside;
setting a temperature and heat flow sensor;
uniformly sticking thermocouples 3 on the wall surfaces on two sides of each wall body 9 to be measured by using aluminum foil adhesive tapes so as to obtain the time-by-time change condition of the wall surface temperature; all the measuring heads of the thermocouples 3 are stuck or wrapped by aluminum foil adhesive tapes to prevent the deviation of the measured temperature value caused by the influence of heat radiation of the surrounding environment; a plurality of thermocouples 3 are arranged in the inner side space and the outer side space of the test box body to obtain gradual change conditions of the ambient air inside and outside the test box body; sticking a heat flow meter on the outer surface of the test box of the wall body 9 to be tested by using mechanical butter so as to obtain the change condition of the heat flow density passing through the wall body 9 to be tested;
step five, setting and debugging a data acquisition system;
connecting the wiring terminals of all thermocouples and the heat flow meter with a data acquisition instrument, and debugging the data acquisition system; all temperature and heat flow signals are collected by a data acquisition instrument and transmitted to a computer in real time for the arrangement and analysis of test results;
step six, installing a wall frame 5;
lifting each wall body frame 5 and respectively installing the wall body frames in angle steel frames of the test box body, binding each wall body frame 5 by two binding bands, and binding each binding band on an upper bracket 10 and a lower bracket 10 which are respectively corresponding;
step seven, all fans 1 are started;
step eight, debugging the heat source 2;
determining the temperature of an indoor air conditioner to be 21 ℃ and starting the air conditioner; when unsteady state thermal performance test is carried out, in order to simulate the outdoor thermal boundary conditions of day and night required by the experiment, a timing controller and a current magnitude controller are debugged and controlled according to the acquired data condition, and the temperature change period of the test is determined to be 24 hours; in each period, the heat source 2 is turned on for 9 hours and turned off for 15 hours so as to achieve periodic parabolic change of the wall surface temperature, and the heat source 2 is made into outdoor heat conditions required by experiments; setting the temperature of the inner side surface of the wall body at 23-30 ℃ (temperature zone 1); when steady-state thermal performance test is carried out, selecting heating power of a heat source 2 which enables the surface temperature of a wall 9 to be tested in the box to be significantly higher than the temperature of an indoor air conditioner, and enabling the heat source 2 to be kept in an open state all the time in the test process;
step nine, performing experimental tests and collecting data at the same time;
and step ten, data arrangement and calculation.
The thermal performance of the wall to be tested is analyzed as follows by combining the test results after finishing;
the temperature change conditions of the surface temperatures of the inside and the outside of the box (the surface temperatures of the outside and the inside of an actual building are respectively simulated) of the two walls 9 to be tested are shown in fig. 5, and the temperature amplitude at each surface and the temperature attenuation multiple of each layer of the wall are shown in fig. 6; it can be seen that phase change walls generally have a greater degree of attenuation and retardation effects on outdoor temperature waves than ordinary walls, especially for PCM-containing layers; fig. 7 shows the variation of the heat flux density of two walls 9 to be tested, wherein the data respectively show the heat flux average value and the heat flux amplitude; the average value and the amplitude of the heat flow of the phase-change wall are smaller than those of the common wall; FIG. 8 shows a thermal resistance curve of the wall 9 under test under steady state thermal conditions; the surface temperature of the wall body 9 to be tested in the test box body is obviously higher than the peripheral test environment temperature by more than 10 ℃, the wall bodies gradually tend to be in a thermal stable state from an initial state, and the thermal resistance of the phase-change wall is slightly higher than that of a common wall.
Example 2
By adopting the testing method of the invention, the unsteady state thermal test is carried out on the same wall body in the embodiment 1 under the boundary condition that the surface temperature of the inner side of the box is 23-47 ℃ (the temperature zone 2).
The test device used is arranged entirely in accordance with claim 1.
The test procedure is as follows:
step one, taking down the wall frame 5;
step two, building a wall body 9 sample to be tested;
a heat preservation material layer is respectively padded at the lower boundary of the central holes 6 of two wall frames 5 of the test box body, and a small wall 9 sample to be tested is respectively built in the central holes 6 of the two wall frames 5; filling the central holes 6 of the remaining two wall frames 5 with a heat insulating material; uniformly sticking thermocouples 3 at two different thickness positions inside the wall 9 to be measured according to the requirement to obtain the temperature gradual change condition of a specific thickness position; uniformly smearing a proper amount of mechanical butter on the contact surfaces among all layers of the wall body to ensure good thermal contact among the surfaces;
filling holes;
filling a sufficient amount of heat insulation material 8 between the peripheral surface of the wall 9 to be tested and the surface of the central hole 6; compacting the heat insulation material 8, spraying heat insulation foam, filling gaps, and ensuring that no air convection heat exchange exists between the inside of the wall 9 to be tested and the outside;
setting a temperature and heat flow sensor;
uniformly sticking thermocouples 3 on the wall surfaces on two sides of each wall body 9 to be measured by using aluminum foil adhesive tapes so as to obtain the time-by-time change condition of the wall surface temperature; all the measuring heads of the thermocouples 3 are stuck or wrapped by aluminum foil adhesive tapes to prevent the deviation of the measured temperature value caused by the influence of heat radiation of the surrounding environment; a plurality of thermocouples 3 are arranged in the inner side space and the outer side space of the test box body to obtain gradual change conditions of the ambient air inside and outside the test box body; sticking a heat flow meter on the outer surface of the test box of the wall body 9 to be tested by using mechanical butter so as to obtain the change condition of the heat flow density passing through the wall body 9 to be tested;
step five, setting and debugging a data acquisition system;
connecting the wiring terminals of all thermocouples and the heat flow meter with a data acquisition instrument, and debugging the data acquisition system; all temperature and heat flow signals are collected by a data acquisition instrument and transmitted to a computer in real time for the arrangement and analysis of test results;
step six, installing a wall frame 5;
lifting each wall body frame 5 and respectively installing the wall body frames in angle steel frames of the test box body, binding each wall body frame 5 by using 2 binding bands, and binding each binding band on an upper bracket 10 and a lower bracket 10 which are respectively corresponding to each other;
step seven, all fans 1 are started;
step eight, debugging the heat source 2;
determining the temperature of an indoor air conditioner to be 21 ℃ and starting the air conditioner; when unsteady state thermal performance test is carried out, in order to simulate the outdoor thermal boundary conditions of day and night required by the experiment, a timing controller and a current magnitude controller are debugged and controlled according to the acquired data condition, and the temperature change period of the test is determined to be 24 hours; in each period, the heat source 2 is turned on for 9 hours and turned off for 15 hours so as to achieve periodic parabolic change of the wall surface temperature, and the heat source 2 is made into outdoor heat conditions required by experiments; setting the temperature of the inner side surface of the wall body box at 23-47 ℃ (temperature zone 2); when steady-state thermal performance test is carried out, selecting heating power of a heat source 2 which enables the surface temperature of a wall 9 to be tested in the box to be significantly higher than the temperature of an indoor air conditioner, and enabling the heat source 2 to be kept in an open state all the time in the test process;
step nine, performing experimental tests and collecting data at the same time;
and step ten, data arrangement and calculation.
The thermal performance of the wall to be tested is analyzed as follows by combining the test results after finishing;
the temperature change conditions of the surface temperatures of the inside and the outside of the box (the surface temperatures of the outside and the inside of an actual building are respectively simulated) of the two walls 9 to be tested are shown in fig. 9, and the temperature amplitude at each surface and the temperature attenuation multiple of each layer of the wall are shown in fig. 10; it can be seen that phase change walls generally have a greater degree of attenuation and retardation effects on outdoor temperature waves than ordinary walls, especially for PCM-containing layers; fig. 11 shows the variation of the heat flux density of two walls 9 to be tested, wherein the data respectively show the heat flux average value and the heat flux amplitude; likewise, the average value and amplitude of the heat flow of the phase-change wall are smaller than those of the common wall;
in addition, as shown by comparing the test results of the two specific embodiments, the effect of the phase change wall in the temperature area 2 is better than that of the temperature area 1, because the temperature of the temperature area 2 at the wall position where the PCM is positioned is more matched with the phase change temperature of the PCM, the PCM can better complete the self melting-solidification periodic phase transformation, thereby fully playing the heat storage and release performances.

Claims (5)

1. The phase-change composite wall thermal performance testing device is characterized by comprising:
the heat-insulating wall comprises a fan (1), a heat source (2), a thermocouple (3), a heat-insulating wall board (4), a wall body frame (5), square holes (6), a structural frame (7), a heat-insulating material (8), a wall body (9) to be tested and a bracket (10);
the structural frame (7) is formed by welding angle steel frames and is used for supporting foot frames;
the heat preservation wallboards (4) with corresponding sizes are arranged in the angle steel frames above and below the structural frame (7); wall frames (5) with corresponding sizes are placed in angle steel grooves around the structural frame (7), heat insulation materials are filled in the frames, each wall frame (5) is detachably fastened by 2 binding bands respectively, and each binding band is tied on an upper bracket (10) and a lower bracket (10) which correspond to each other respectively; the upper and lower heat-insulating wallboards (4) and the surrounding wall frames (5) form a test box body; the outer surface and the inner surface of the wall body (9) to be tested in actual use face the inner environment space and the outer environment space of the test box body respectively in the test box body;
a square hole (6) is arranged at the center of the wall body frame (5); a small wall body (9) to be measured is built in a central hole (6) of the wall body frame (5), and the size of the central hole (6) is larger than that of the wall body (9) to be measured; the thermal insulation material (8) is filled between the peripheral surface of the wall body (9) to be tested and the inner surface of the central hole (6); the heat sources (2) of the wall body (9) to be tested are four incandescent lamps positioned at the central position inside the test box body, and the four incandescent lamps are respectively aligned to the central areas of the four wall bodies (9) to be tested; the on and off of the heat source (2) are controlled by a timing controller, the brightness is controlled by a current magnitude controller, and the simulation of the outdoor thermal boundary conditions of day and night can be realized through debugging; and the indoor thermal boundary conditions are controlled by an air conditioner in the laboratory;
fans (1) are respectively arranged at four corners of the test box body to ensure air flow and thermal uniformity in the test box body; the middle part of the heat-insulating wallboard (4) at the upper end of the test box body is provided with a hole, and a fan (1) is embedded in the hole to promote the air flow between the inner side and the outer side of the test box body, and the purpose of cooling the environment at the inner side of the test box body is achieved; if the air temperature outside the test box is insufficient to cool the inside of the test box, a small air conditioning fan is connected with the middle opening through a ventilation pipeline so as to strengthen the cooling effect of the air environment in the test box.
2. The phase-change composite wall thermal performance testing device according to claim 1, wherein: the side length of the structural frame (7) is in the range of 1.0 m-1.5 m.
3. The phase-change composite wall thermal performance testing device according to claim 1, wherein: the outer layer materials of the heat-insulating wallboard (4) and the wall frame (5) are wood materials with the thickness ranging from 0.008m to 0.015 m; the heat-insulating wallboard (4) contains a heat-insulating material layer with the thickness of 0.08 m-0.12 m, and has a heat insulation effect between the inner side and the outer side of the test box body; the wall frame (5) is set to be 0.2-0.4 m thick according to the thickness of the wall to be measured; the heat insulation material is any one of conventional heat insulation material foamed polyethylene, foamed polystyrene and foamed polyurethane.
4. The phase-change composite wall thermal performance testing device according to claim 1, wherein: the heat source (2) selects an incandescent lamp with the power of 50W-300W according to actual needs.
5. The testing method of the phase-change composite wall thermal performance testing device according to any one of claims 1 to 4, comprising the following steps:
step one, taking down the wall frame from the test box body
Releasing the binding belt, and respectively taking down the four wall frames (5) of the test box body to load the wall to be tested; the wall body frame (5) is filled with heat insulation materials, so that lateral heat conduction of the wall body (9) to be tested in the testing process is prevented;
step two, building the wall to be tested to obtain an intermediate
A layer of heat preservation material layer is respectively padded at the lower boundaries of the central holes (6) of the four wall frames (5) of the test box body, and then a wall (9) to be tested is respectively built in the four central holes (6); if the number of the built walls (9) to be tested is smaller than 4, filling the central holes (6) of the rest wall frames (5) with heat insulation materials; if the built wall body (9) to be tested is of a multi-layer structure, the bonding mode among all layers is concrete or mortar, or mechanical butter is uniformly smeared on the contact surfaces among all layers of the wall body so as to ensure good thermal contact among the surfaces;
obtaining an intermediate after the step two is completed, wherein the intermediate comprises four wall frames (5);
filling the central hole
In order to better prevent lateral heat conduction of the wall body (9) to be measured and enable the size selection of the wall body (9) to be measured to be more elastic, heat preservation materials are filled between the inner surface of the central hole (6) of the wall body frame (5) and the outer surfaces around the wall body (9) to be measured; compacting the heat insulation material (8), spraying and filling gaps by using heat insulation foam, and enabling the inner surfaces of the wall body (9) to be tested, the heat insulation material and the central hole (6) to be in a close contact state so as to ensure that no air convection heat exchange exists between the inside of the wall body (9) to be tested and the outside;
step four, setting a temperature and heat flow sensor
Uniformly sticking thermocouples (3) on the outer surface of each wall (9) to be measured in the thickness direction by using aluminum foil adhesive tapes so as to obtain the time-by-time change condition of the wall temperature; all the measuring heads of the thermocouples (3) are stuck or wrapped by aluminum foil adhesive tapes so as to prevent the deviation of the measured temperature value caused by the influence of heat radiation of the surrounding environment; a plurality of thermocouples (3) are arranged in the inner side space and the outer side space of the test box body to obtain the temperature time-by-time change condition of the ambient air inside and outside the test box body; sticking a heat flow meter on the part of the wall body (9) to be tested, which is positioned on the outer surface of the test box, by using mechanical butter so as to obtain the change condition of the heat flow density passing through the wall body (9) to be tested;
according to the requirements of experimental tests, uniformly sticking thermocouples (3) at different thickness positions inside the wall body (9) to be tested in the second step to obtain the temperature gradual change condition at the specific thickness;
step five, setting and debugging a data acquisition system
Connecting the wiring terminals of all thermocouples and the heat flow meter with a data acquisition instrument, and debugging the data acquisition system; all temperature and heat flow signals are collected by a data acquisition instrument and transmitted to a computer in real time for the arrangement and analysis of test results, and acquisition software of the corresponding data acquisition instrument is installed on the computer;
step six, installing a wall frame
The intermediate body is arranged in an angle steel frame of the test box body, four wall frames (5) in the intermediate body are respectively tightly bound with the surrounding four sides of the angle steel frame by two binding bands, and each binding band is tied on an upper bracket (10) and a lower bracket (10) corresponding to the intermediate body;
step seven, turning on all fans
Step eight, debugging the heat source
Starting an air conditioner, and adjusting the external environment temperature of the test box body to simulate the indoor temperature of the actual use environment of the wall body to be tested; further, the outdoor temperature of the actual use environment of the wall to be tested is simulated by adjusting the environmental temperature in the test box body through a fan and a heat source;
if the thermal performance is unsteady state thermal performance test, in order to simulate the actual day and night outdoor thermal boundary conditions of the wall to be tested, the timing controller and the current magnitude controller are debugged and controlled according to the acquired data conditions, so that the switching time and the power magnitude of the heat source (2) in each period are determined, and the outdoor thermal conditions required by the experiment are manufactured by utilizing the heat source (2);
if the thermal performance is tested in a steady state, the heat source (2) is always kept in an open state in the test process, so that the surface temperature of the wall (9) to be tested in the test box body is obviously higher than the peripheral test environment temperature;
step nine, experimental testing the thermal performance of the wall to be tested, and collecting test data
Step ten, sorting and calculating the test data
Sorting data acquired by a data acquisition instrument; calculating attenuation times and delay time values of the wall body by using the unsteady state test results; calculating to obtain a thermal resistance value of the wall body by using a steady-state test result;
the attenuation multiple is the ratio of the temperature amplitude of the inner side surface of the box of the wall body (9) to be detected to the temperature amplitude of the outer side surface of the box;
the delay time is the difference between the peak time of the surface temperature of the outer side of the box of the wall body (9) to be detected and the peak time of the surface temperature of the inner side of the box, and the unit is h;
the thermal resistance value is the ratio of the temperature difference at two ends of the wall body (9) to be measured to the heat flow density passing through the wall body, and the unit is m 2 ·K·W -1 。
CN202011162519.1A 2020-10-27 2020-10-27 Phase-change composite wall thermal performance testing device and method Active CN114486997B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011162519.1A CN114486997B (en) 2020-10-27 2020-10-27 Phase-change composite wall thermal performance testing device and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011162519.1A CN114486997B (en) 2020-10-27 2020-10-27 Phase-change composite wall thermal performance testing device and method

Publications (2)

Publication Number Publication Date
CN114486997A CN114486997A (en) 2022-05-13
CN114486997B true CN114486997B (en) 2023-08-18

Family

ID=81470277

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011162519.1A Active CN114486997B (en) 2020-10-27 2020-10-27 Phase-change composite wall thermal performance testing device and method

Country Status (1)

Country Link
CN (1) CN114486997B (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2965922A1 (en) * 2010-10-12 2012-04-13 France Etat Ponts Chaussees DEVICE AND METHOD FOR IDENTIFYING THE CONDUCTIVITY AND / OR THE THERMAL CAPACITY OF A WALL
CN102879424A (en) * 2012-10-10 2013-01-16 信阳天意节能技术有限公司 Measurement method for thermal performance of phase change building heat-insulation material
CN106442609A (en) * 2016-03-10 2017-02-22 上海众材工程检测有限公司 Evaluation method for equivalent heat conductivity coefficient of solid-solid phase change thermal insulation material
CN109187626A (en) * 2018-07-11 2019-01-11 中国矿业大学 A kind of method and test device of two sides thermal characteristic of wall contrast test
CN109932384A (en) * 2018-12-19 2019-06-25 同济大学 A kind of test device and method for building PCM wall
WO2019136885A1 (en) * 2018-01-09 2019-07-18 中国计量大学 Steady-state test method for heat-conducting property in the direction along plane of sheet material

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2965922A1 (en) * 2010-10-12 2012-04-13 France Etat Ponts Chaussees DEVICE AND METHOD FOR IDENTIFYING THE CONDUCTIVITY AND / OR THE THERMAL CAPACITY OF A WALL
CN102879424A (en) * 2012-10-10 2013-01-16 信阳天意节能技术有限公司 Measurement method for thermal performance of phase change building heat-insulation material
CN106442609A (en) * 2016-03-10 2017-02-22 上海众材工程检测有限公司 Evaluation method for equivalent heat conductivity coefficient of solid-solid phase change thermal insulation material
WO2019136885A1 (en) * 2018-01-09 2019-07-18 中国计量大学 Steady-state test method for heat-conducting property in the direction along plane of sheet material
CN109187626A (en) * 2018-07-11 2019-01-11 中国矿业大学 A kind of method and test device of two sides thermal characteristic of wall contrast test
CN109932384A (en) * 2018-12-19 2019-06-25 同济大学 A kind of test device and method for building PCM wall

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Experimental and numerical study of thermal performance of the PCM wall with solar radiation;Xie J et al.;Constr Build Mater;全文 *

Also Published As

Publication number Publication date
CN114486997A (en) 2022-05-13

Similar Documents

Publication Publication Date Title
US4553852A (en) Apparatus and method for heat flow measurement
Piot et al. Experimental wooden frame house for the validation of whole building heat and moisture transfer numerical models
Sun et al. Laboratory assessment of residential building walls containing pipe-encapsulated phase change materials for thermal management
Ricciu et al. Thermal characterization of insulating materials
Buratti et al. Thermal conductivity measurements by means of a new ‘Small Hot-Box’apparatus: Manufacturing, calibration and preliminary experimental tests on different materials
Ferrari et al. The thermal performance of walls under actual service conditions: Evaluating the results of climatic chamber tests
CN102879424B (en) Measurement method for thermal performance of phase change building heat-insulation material
CN103308550B (en) The relative Determination of conductive coefficients method of phase-change energy-storage composite material
Yu et al. Experimental investigation of cooling performance of a novel HVAC system combining natural ventilation with diffuse ceiling inlet and TABS
Nosrati et al. Long-term performance of aerogel-enhanced materials
CN110702357A (en) Hot and humid climate wind tunnel and multi-field coupling control system thereof
Zhang et al. Experimental study on the building evaporative cooling by using the Climatic Wind Tunnel
CN104897721A (en) Building wall phase-change heat insulation effect testing system and using method thereof
Marani et al. An innovative apparatus for simulating daily temperature for investigating thermal performance of wallboards incorporating PCMs
Choi et al. Influence of the moisture driving force of moisture adsorption and desorption on indoor hygrothermal environment and building thermal load
hua Tian et al. Experimental study on the thermal performance of a wall coated with a phase-change, energy-storing mortar layer during summer
Zhang et al. A parametric model on thermal evaluation of building envelopes containing phase change material
CN114486997B (en) Phase-change composite wall thermal performance testing device and method
Zhang et al. A reduced-scale experimental method for the thermal evaluation of building envelopes outfitted with phase change materials
Peavy et al. Dynamic thermal performance of an experimental masonry building
Wilkes et al. Thermal performance of residential attic insulation
Asli et al. Numerical and experimental investigation of heat and mass transfer within bio-based material
Meissner et al. A full-scale experimental set-up for evaluating the moisture buffer effects of porous material
Sun et al. A reduced-scale experiment to evaluate the thermal performance of building envelopes containing phase change material spheres
CN220861527U (en) Teaching experiment table for heat transfer performance test of building envelope

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant