On-site detection device for fire resistance of steel structure intumescent fire retardant coating

Abstract

The invention belongs to the technical field of paint detection, and particularly relates to a fire resistance on-site detection device for steel structure intumescent fire retardant paints.When the device works, firstly, a furnace body is arranged on a construction site, a steel structure test piece is placed in the furnace body, the furnace body is heated, and in the process, temperature change information in the furnace is obtained through a first obtaining module; the temperature change information of the test piece is obtained through a second obtaining module, and the obtained information is sorted into a furnace temperature-time curve, a test piece temperature-time curve and the average heating rate of the furnace body through an information processing module; according to the furnace temperature-time curve, the test piece temperature-time curve and the average heating rate of the furnace body, the average thermal resistance of the coating in the complete expansion stage under the standard condition is obtained, so that the effect of detecting the fire resistance of the fireproof coating on site is achieved.

Description

Technical Field

[0001] This invention belongs to the field of coating testing technology, and in particular relates to a device for on-site testing of the fire resistance performance of intumescent fireproof coatings for steel structures. Background Technology

[0002] Fire poses a serious threat to the safety of steel structures. High temperatures can significantly reduce the mechanical properties of steel, leading to structural collapse and loss of life and property. To ensure the safety of steel building structures during fire, fire protection is crucial. Fire-retardant coatings, due to their ease of application and good decorative properties, have become the mainstream choice for fire protection of steel structures. Intumescent fire-retardant coatings, as the mainstream product, delay the heating of the substrate and enhance thermal insulation performance by being applied to the surface of components, thus postponing structural failure.

[0003] The fire resistance of building components is a key indicator of their ability to withstand rapid temperature increases during a fire, directly impacting building safety. However, existing standard testing methods are costly and time-consuming, and due to limitations in current technology and equipment, current domestic steel structure fire protection design and acceptance codes do not explicitly specify on-site testing requirements for the fire resistance performance of fire-retardant coatings. The market is currently flooded with counterfeit and substandard intumescent fire-retardant coatings, and the lack of effective on-site inspection methods makes it difficult to identify substandard products and other violations.

[0004] Therefore, a field testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a field testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures, in order to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A device for on-site testing of the fire resistance performance of intumescent fire-retardant coatings for steel structures, comprising:

[0008] A furnace body is used to be set up at the construction site, and the furnace body is used to hold steel structure test specimens, the outer side of which is coated with paint;

[0009] The first acquisition module is used to acquire information on temperature changes inside the furnace.

[0010] The second acquisition module is used to acquire specimen temperature change information;

[0011] The information processing module is used to obtain the furnace temperature-time curve, the specimen temperature-time curve, and the average heating rate of the furnace body based on the furnace temperature change information and the steel structure specimen temperature change information.

[0012] The calculation module is used to obtain the average thermal resistance of the coating during the full expansion stage under test conditions based on the furnace temperature-time curve and the specimen temperature-time curve.

[0013] The fitting relationship between the furnace heating rate and the average thermal resistance of the coating during the full expansion stage was obtained based on the average heating rate of the furnace body and the average thermal resistance of the coating under test conditions.

[0014] The average thermal resistance of the coating during the full expansion stage under standard conditions is obtained based on the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under test conditions, the fitting relationship between the furnace heating rate and the average thermal resistance of the coating during the full expansion stage under standard conditions, and the preset relationship between the average thermal resistance of the coating during the full expansion stage under test conditions and the average thermal resistance of the coating during the full expansion stage under standard conditions.

[0015] The on-site testing device for the fire resistance performance of intumescent fireproof coatings for steel structures of the present invention also includes an equivalent correction module. The equivalent correction module is electrically connected to the calculation module. The equivalent correction module is used to obtain the corrected average thermal resistance of the coating during the full expansion stage based on the preset relationship between the average thermal resistance of the coating during the full expansion stage under standard conditions and the thermal boundary condition correction parameters.

[0016] The average thermal resistance of the coating at different expansion stages is obtained based on a preset relationship between the average thermal resistance of the coating at the fully expanded stage and the average thermal resistance of the coating at different expansion stages.

[0017] The simulated temperature rise curve of the steel structure specimen was obtained based on the average thermal resistance of the coating at different expansion stages. The time corresponding to when the steel structure specimen reached 540℃ was obtained based on the simulated temperature rise curve of the steel structure specimen. The equivalent thermal resistance of the coating under standard conditions was obtained based on the time corresponding to when the steel structure specimen reached 540℃.

[0018] The on-site testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures of the present invention also includes a comparison module, which is electrically connected to the equivalent correction module. The comparison module is used to compare the equivalent thermal resistance of the coating under standard conditions with the input equivalent thermal resistance of the coating.

[0019] In the on-site testing device for the fire resistance performance of intumescent fireproof coatings for steel structures of the present invention, the top and bottom surfaces of the furnace body are provided with first openings, and the two first openings are arranged correspondingly. One end of the furnace body is provided with a second opening, and the two first openings are connected to the second opening. Two first furnace doors are provided at the first opening, and the two first furnace doors are arranged opposite to each other and adapted to the first opening. Two second furnace doors are provided at the second opening, and the two second furnace doors are arranged opposite to each other and adapted to the second opening.

[0020] In the on-site testing device for the fire resistance performance of intumescent fireproof coatings for steel structures of the present invention, two second furnace doors are respectively arranged on two opposite sides of the second opening. The second furnace doors are hinged to the furnace body by a plurality of second hinges. The second hinges are arranged on the outer side wall of the furnace body. One of the second furnace doors is rotatably connected to a stop bar on the side outside the furnace body, and the other second furnace door is fixedly connected to a locking block on the side outside the furnace body. The locking block is detachably connected to the stop bar.

[0021] In the on-site testing device for the fire resistance performance of intumescent fireproof coatings for steel structures of the present invention, a sliding groove is provided on one side of each of the two first furnace doors. The two sliding grooves are arranged opposite each other. One end of one of the sliding grooves extends out of the first furnace door and communicates with the other sliding groove. A slide rail is fixedly connected to the two opposite side walls of the sliding groove. The two slide rails are arranged parallel and symmetrically. The slide rails are slidably connected in slots. The slots are opened on two opposite sides of the sliding cover. The sliding cover is detachably connected to the first furnace door.

[0022] In the on-site testing device for the fire resistance performance of intumescent fireproof coatings for steel structures of the present invention, one of the second furnace doors is rotatably connected to a stop bar on one side of the furnace body, and the other second furnace door is fixedly connected to a locking block on one side of the furnace body, and the locking block is detachably connected to the stop bar.

[0023] In the on-site testing device for the fire resistance performance of intumescent fireproof coatings for steel structures of the present invention, a frame is fixedly connected to the bottom surface of the furnace body, and rollers are installed at the four corners of the bottom surface of the frame.

[0024] In the on-site testing device for the fire resistance performance of intumescent fireproof coatings for steel structures of the present invention, observation ports are provided on the two opposite side walls of the furnace body.

[0025] In the on-site testing device for the fire resistance performance of intumescent fireproof coatings for steel structures of the present invention, an oxygen cylinder and a gas cylinder are fixedly installed on the frame, and both the oxygen cylinder and the gas cylinder are connected to the furnace body.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] When the device of the present invention is in operation, a furnace body is first set up at the construction site, a steel structure specimen is placed inside the furnace body, and the furnace body is heated. During this process, the first acquisition module acquires the temperature change information inside the furnace, and the second acquisition module acquires the temperature change information of the specimen. The information processing module organizes the acquired information into a furnace temperature-time curve, a specimen temperature-time curve, and the average heating rate of the furnace body. The calculation module acquires the average thermal resistance of the coating during the full expansion stage under test conditions, the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under test conditions, and the average thermal resistance of the coating during the full expansion stage under standard conditions based on the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under test conditions, the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under standard conditions, the average thermal resistance of the coating during the full expansion stage under test conditions, and the preset relationship between the average thermal resistance of the coating during the full expansion stage under standard conditions. This serves to test the fire resistance performance of fire-retardant coatings on-site. Attached Figure Description

[0028] 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 described 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.

[0029] Figure 1 This is a schematic diagram of the overall structure of the furnace door when it is open in this invention;

[0030] Figure 2 This is a schematic diagram of the overall structure of the furnace door when it is closed in this invention;

[0031] Figure 3 This is a schematic diagram of the overall structure of the furnace body in this invention;

[0032] Figure 4 This is a schematic diagram of the overall structure of the vehicle frame in this invention;

[0033] The components are as follows: 1. Furnace body; 2. First furnace door; 3. First hinge; 4. First stop block; 5. Sliding cover; 6. First opening; 7. Control system; 8. Observation port; 9. Car frame; 10. Second furnace door; 11. Stop bar; 12. Locking block; 13. Second hinge; 14. Second opening; 15. Oxygen cylinder; 16. Roller; 17. Slide groove; 18. Gas cylinder. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] Reference Figures 1 to 4 This invention discloses a field testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures, comprising:

[0037] Furnace body 1 is used to be set up at the construction site and to hold steel structure test specimens, the outer side of which is coated with paint.

[0038] The first acquisition module is used to acquire information on temperature changes inside the furnace.

[0039] The second acquisition module is used to acquire specimen temperature change information;

[0040] The first and second acquisition modules can select contact temperature measurement devices, such as expansion thermometers, resistance thermometers, and thermocouple thermometers, or non-contact temperature measurement devices, such as radiation pyrometers, infrared thermometers, and fiber optic thermometers. They can also select intelligent and integrated temperature sensors, such as digital sensors and temperature transmitters.

[0041] The information processing module is used to obtain the furnace temperature-time curve, the specimen temperature-time curve, and the average heating rate of furnace body 1 based on the furnace temperature change information and the steel structure specimen temperature change information.

[0042] The calculation module is used to obtain the average thermal resistance of the coating during the full expansion stage under test conditions based on the furnace temperature-time curve and the specimen temperature-time curve.

[0043] The fitting relationship between the furnace heating rate and the average thermal resistance of the coating during the full expansion stage was obtained based on the average heating rate of furnace body 1 and the average thermal resistance of the coating under the test conditions.

[0044] The average thermal resistance of the coating during the full expansion stage under standard conditions is obtained based on the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under experimental conditions, the fitting relationship between the furnace heating rate and the average thermal resistance of the coating during the full expansion stage under standard conditions, and the preset relationship between the average thermal resistance of the coating during the full expansion stage under experimental conditions and the average thermal resistance of the coating during the full expansion stage under standard conditions.

[0045] When the device of the present invention is in operation, a furnace body 1 is first set up at the construction site, a steel structure specimen is placed inside the furnace body 1 and the furnace body 1 is heated. During this process, the first acquisition module acquires the temperature change information inside the furnace, the second acquisition module acquires the temperature change information of the specimen, and the information processing module organizes the acquired information into a furnace temperature-time curve, a specimen temperature-time curve and the average heating rate of the furnace body. The calculation module acquires the average thermal resistance of the coating during the full expansion stage under test conditions, the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under test conditions, and the average thermal resistance of the coating during the full expansion stage under standard conditions based on the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under test conditions, the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under standard conditions, the average thermal resistance of the coating during the full expansion stage under test conditions and the preset relationship between the average thermal resistance of the coating during the full expansion stage under standard conditions, thereby playing the role of on-site testing of the fire resistance performance of fireproof coatings.

[0046] In one alternative scheme, an equivalent correction module is also included. The equivalent correction module is electrically connected to the calculation module. The equivalent correction module is used to obtain the corrected average thermal resistance of the coating during the full expansion stage based on the preset relationship between the average thermal resistance of the coating during the full expansion stage under standard conditions and the thermal boundary condition correction parameters.

[0047] The average thermal resistance of the coating at different expansion stages is obtained based on the preset relationship between the average thermal resistance of the coating at the full expansion stage and the average thermal resistance of the coating at different expansion stages.

[0048] The simulated temperature rise curves of the steel structure specimens were obtained based on the average thermal resistance of the coating at different expansion stages. The time corresponding to when the steel structure specimens reached 540℃ was obtained based on the simulated temperature rise curves of the steel structure specimens. The equivalent thermal resistance of the coating under standard conditions was obtained based on the time corresponding to when the steel structure specimens reached 540℃.

[0049] In one alternative embodiment, a comparison module is also included, which is electrically connected to the equivalent correction module. The comparison module is used to compare the equivalent thermal resistance of the coating under standard conditions with the input equivalent thermal resistance of the coating.

[0050] A control system 7 is also installed on the outer wall of the furnace body 1. The equivalent correction module, comparison module, information processing module and calculation module are all integrated in the control system 7. The control system 7 is a programmable controller or a microcontroller. The equivalent correction module, comparison module, information processing module and calculation module are programs built into the control system 7.

[0051] In one alternative embodiment, the top and bottom surfaces of the furnace body 1 are provided with first openings 6, and the two first openings 6 are arranged correspondingly. One end of the furnace body 1 is provided with a second opening 14, and the two first openings 6 are connected to the second opening 14. Two first furnace doors 2 are provided at the first opening 6, and the two first furnace doors 2 are arranged opposite each other and adapted to the first opening 6. Two second furnace doors 10 are provided at the second opening 14, and the two second furnace doors 10 are arranged opposite each other and adapted to the second opening 14.

[0052] This setup opens the two interconnected first openings 6 and second opening 14, making it convenient to place the steel structure specimen inside the furnace body 1.

[0053] In one alternative, two first furnace doors 2 are respectively located on two opposite sides of the first opening 6. The first furnace doors 2 are hinged to the furnace body 1 by multiple first hinges 3. The first hinges 3 are located on the outer side wall of the furnace body 1. Two first stops 4 are rotatably connected to the outer side wall of the furnace body 1. The two first stops 4 are symmetrically arranged with the two first furnace doors 2 respectively.

[0054] The first furnace door 2 is hinged to the furnace body 1 by multiple first hinges 3 and the first hinges 3 are set on the outer side wall of the furnace body 1, so that the first furnace door 2 can be opened to the outside of the furnace body 1. After the first furnace door 2 is closed, the two first stops 4 rotate and abut against the first furnace door 2 to prevent the first furnace door 2 from opening.

[0055] In one alternative, each of the two first furnace doors 2 has a sliding groove 17 on one of their opposite sides. The two sliding grooves 17 are arranged opposite each other. One end of one sliding groove 17 extends out of the first furnace door 2 and communicates with the other sliding groove 17. Slide rails are fixed to the two opposite side walls of the sliding grooves 17. The two slide rails are parallel and symmetrically arranged. The slide rails are slidably connected in slots. The slots are opened on the two opposite sides of the sliding cover 5. The sliding cover 5 is detachably connected to the first furnace door 2.

[0056] The sliding cover 5 is detachably connected to the slide groove 17 via a matching slide rail and slot. When using steel structure specimens of different specifications and styles, different sliding covers 5 are used.

[0057] In one alternative embodiment, two second furnace doors 10 are respectively located on two opposite sides of the second opening 14. The second furnace doors 10 are hinged to the furnace body 1 by a plurality of second hinges 13. The second hinges 13 are located on the outer side wall of the furnace body 1. One of the second furnace doors 10 is rotatably connected to a stop bar 11 on the side outside the furnace body 1, and the other second furnace door 10 is fixedly connected to a locking block 12 on the side outside the furnace body 1. The locking block 12 and the stop bar 11 are detachably connected.

[0058] After closing the second furnace door 10, connect the stop bar 11 to the locking block 12 to lock the second furnace door 10.

[0059] In one alternative embodiment, a frame 9 is fixedly connected to the bottom surface of the furnace body 1, and rollers 16 are installed at each of the four corners of the bottom surface of the frame 9. The frame is used to support the furnace body 1, the oxygen cylinder 15, and the gas cylinder 18. The rollers 16 are omnidirectional wheels with self-locking function, which facilitates the movement of the furnace body 1 to the construction site and its fixation.

[0060] In one alternative, observation ports 8 are provided on both opposite side walls of the furnace body 1.

[0061] The observation port 8 allows staff to observe the changes in the steel structure specimens inside the furnace body 1.

[0062] In one alternative embodiment, an oxygen cylinder 15 and a gas cylinder 18 are fixedly mounted on the frame 9, and both the oxygen cylinder 15 and the gas cylinder 18 are connected to the furnace body 1. Both the oxygen cylinder 15 and the gas cylinder 18 are connected to the combustion chamber inside the furnace body 1 via high-strength corrugated hoses.

[0063] Specific testing methods:

[0064] Install the sliding cover 5, which is adapted to the shape of the steel structure specimen, in the sliding groove 17. Place the steel structure specimen coated with fireproof paint in the furnace body 1 and close the first furnace door 2 and the second furnace door 10. Rotate the first stop block 4 to abut against the first furnace door 2. Rotate the stop rod 11 to engage with the locking block 12. Open the oxygen cylinder 15 and the gas cylinder 18 and ignite them in the combustion chamber to heat the furnace body 1. Observe the changes of the steel structure specimen through the observation port 8. Obtain the temperature change information of the steel structure specimen through the high-temperature thermocouple embedded in the steel structure specimen. Obtain the temperature change information inside the furnace body 1 through the temperature sensor. Obtain the furnace temperature-time curve, the specimen temperature-time curve and the average heating rate of the furnace body 1 based on the furnace temperature change information and the specimen temperature change information. Obtain the average thermal resistance of the coating during the complete expansion stage under the test conditions based on the furnace temperature-time curve and the specimen temperature-time curve.

[0065] First, the instantaneous thermal resistance curve of the coating is calculated based on the furnace temperature-time curve and the specimen temperature-time curve. The calculation formula is as follows:

[0066]

[0067] Where R(t) is the instantaneous thermal resistance curve of the coating under the test conditions, and d i λ(t) is the dry film thickness of the coating; λ(t) is the heat transfer coefficient of the coating; c s It is the specific heat capacity of steel under fire protection, ρ s It is the density of steel under fire protection, A i V is the fire-exposed surface area per unit length of fire-protected steel structural member; A is the volume per unit length of fire-protected steel structural member. i / V is the cross-sectional shape factor, and the specimen temperature-time curve includes T.s (t), with an initial value of 20℃, the furnace temperature-time curve includes T g (t), where Δt is the calculation time step, which is based on the thermocouple sampling frequency and should not exceed 15s;

[0068] The average thermal resistance R during the full expansion phase of the coating under test conditions was calculated based on the instantaneous thermal resistance curve of the coating under test conditions. e-Test The calculation formula is as follows:

[0069]

[0070] Where R(t) is R(T) s ), T s The temperature of the steel structure specimen;

[0071] Based on the average thermal resistance of the intumescent fire-retardant coating during the full expansion stage under different heating rates inside furnace 1, the relationship curve between the two was organized and fitted to obtain the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under the experimental conditions:

[0072] R e (v)=-0.0001v 2 +0.004v +0.056;

[0073] Where v is the average heating rate of furnace body 1 (°C / min), which is the average heating rate of furnace temperature corresponding to component temperature of 400-600°C. The heating rate corresponding to the ISO834 furnace temperature curve can be taken as 4.5-5.0°C / min.

[0074] Based on the measured value of thermal resistance R under experimental conditions e-Test Experimental conditions: Thermal resistance-furnace heating rate model theoretical value R e-Test (v Test The theoretical value R of the ISO 834 conditional thermal resistance-furnace heating rate model is compared with that of the model. e (v ISO ), the average thermal resistance R of the component during the full expansion stage under the standard ISO834 heating condition. e ;

[0075]

[0076] R e (v ISO R represents the fitted relationship between the furnace heating rate and the average thermal resistance of the coating under standard conditions. e-Test (v Test The figure represents the fitted relationship between the furnace heating rate and the average thermal resistance of the coating under the experimental conditions.

[0077] Based on the thermal boundary conditions of the steel structure specimens under experimental conditions, the average thermal resistance of the coating under the fitted standard conditions is corrected as follows:

[0078] R′ e =α BC ×R e ;

[0079] Among them, R' e To fit the average thermal resistance of the coating under standard conditions; thermal boundary condition correction parameter α BC The specific value is determined based on the location and length of the fire-receiving zone of the heating device.

[0080] Based on the average thermal resistance of the coating under the corrected fitting standard conditions, the average thermal resistances R1 and R2 corresponding to the melting and expansion foaming stages of the coating under the ISO834 heating conditions are calculated according to the three-stage average thermal resistance model.

[0081]

[0082] Average thermal resistance R of coatings at different characteristic expansion stages i (T s The average thermal resistance of the corresponding stage is taken according to the iterative furnace temperature range.

[0083] The formula for calculating the simulated temperature rise curve of the steel structure specimen under standard conditions is as follows:

[0084]

[0085] The design value of the furnace temperature heating curve in ISO 834 standard is T. g-ISO (t+Δt);

[0086] Based on the simulated temperature rise curve of the steel structure specimen under standard conditions, the time t0 corresponding to when the component reaches 540℃ is collected; substituting the equivalent thermal resistance calculation formula recommended in GB51249 "Technical Specification for Fire Protection of Steel Structures", the equivalent thermal resistance result R under the standard requirements is calculated. e ''. Among them, T s Take 540℃, T s0 Take 20℃;

[0087]

[0088] Considering the actual differences in the dry film thickness (d0) of intumescent fire-retardant coatings used on construction sites, and based on the dry film thickness of the coating on the steel structure specimens under test conditions, the equivalent thermal resistance (R) under standard requirements is calculated. e Corrections to be made:

[0089]

[0090] Among them, Re0 The equivalent thermal resistance result under the standard requirements after correction for coating dry film thickness; coating dry film thickness correction factor. The specific value is yet to be determined;

[0091] The final equivalent thermal resistance of the coating is compared with the standard value of the fire-retardant coating given by the coating manufacturer to determine whether the fire protection used on site meets the requirements.

[0092] Taking a certain brand of intumescent fire retardant coating as an example, steel plate specimens coated with this fire retardant coating were tested in furnace body 1 according to v Test The equivalent thermal resistance of the coating was tested on-site at a rate of 4℃ / min, and the measured value of the thermal resistance R under this test condition was obtained. e-Test The value is 0.07075. The theoretical value R is calculated according to the thermal resistance-furnace heating rate model under experimental conditions. e-Test (v Test The value is 0.07024, which is the theoretical value R of the ISO 834 conditional thermal resistance-furnace heating rate model. e (v ISO The value is 0.07198, which is converted to the average thermal resistance R of the component during the full expansion stage under standard ISO834 heating conditions. e The value is 0.07250; according to the three-stage average thermal resistance model, the average thermal resistances R1 and R2 corresponding to the melting and expansion foaming stages of the coating under ISO834 heating conditions are calculated to be 0.02175 and 0.11600, respectively; based on the average thermal resistances R1, R2, and R of the coating corresponding to different characteristic expansion stages, the values ​​are calculated to be 0.07250. e Calculate the simulated temperature rise curve ΔT of the steel structure specimen under standard conditions. s Based on the simulated temperature rise curve of the steel structure specimen under standard conditions, the time t0 corresponding to when the component reaches 540℃ was collected; substituting the equivalent thermal resistance calculation formula recommended in GB51249 "Technical Specification for Fire Protection of Steel Structures", the equivalent thermal resistance result R under the standard requirements was obtained after calculation and correction for coating dry film thickness. e0 The result is 0.06487, which is about -6% different from the standard test result of 0.06950 for the equivalent thermal resistance of the brand's intumescent fire retardant coating. This indicates that when the algorithm is used to calculate the equivalent thermal resistance of intumescent fire retardant coating under non-standard temperature rise curve testing conditions on site, it can ensure high accuracy while showing a slightly conservative result tendency.

[0093] 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.

[0094] 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 device for on-site testing of the fire resistance performance of intumescent fire-retardant coatings for steel structures, characterized in that, include: A furnace body (1) is used to be set up at the construction site, and the furnace body (1) is used to hold steel structure test pieces, the outer side of which is coated with paint; The first acquisition module is used to acquire information on temperature changes inside the furnace. The second acquisition module is used to acquire specimen temperature change information; The information processing module is used to obtain the furnace temperature-time curve, the specimen temperature-time curve, and the average heating rate of the furnace body (1) based on the furnace temperature change information and the steel structure specimen temperature change information. The calculation module is used to obtain the average thermal resistance of the coating during the full expansion stage under test conditions based on the furnace temperature-time curve and the specimen temperature-time curve. The fitting relationship between the furnace heating rate and the average thermal resistance of the coating during the full expansion stage was obtained based on the average heating rate of the furnace body (1) and the average thermal resistance of the coating under test conditions. The average thermal resistance of the coating during the full expansion stage under standard conditions is obtained based on the fitting relationship between the furnace heating rate and the average thermal resistance of the coating under test conditions, the fitting relationship between the furnace heating rate and the average thermal resistance of the coating during the full expansion stage under standard conditions, and the preset relationship between the average thermal resistance of the coating during the full expansion stage under test conditions and the average thermal resistance of the coating during the full expansion stage under standard conditions.

2. The on-site testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures according to claim 1, characterized in that, It also includes an equivalent correction module, which is electrically connected to the calculation module. The equivalent correction module is used to obtain the corrected average thermal resistance of the coating during the full expansion stage based on a preset relationship between the average thermal resistance of the coating during the full expansion stage under standard conditions and the thermal boundary condition correction parameters; to obtain the average thermal resistance of the coating during different expansion stages based on a preset relationship between the corrected average thermal resistance of the coating during the full expansion stage and the average thermal resistance of the coating during different expansion stages; to obtain the simulated temperature rise curve of the steel structure specimen based on the average thermal resistance of the coating during different expansion stages; to obtain the time corresponding to the steel structure specimen reaching 540℃ based on the simulated temperature rise curve of the steel structure specimen; and to obtain the equivalent thermal resistance of the coating under standard conditions based on the time corresponding to the steel structure specimen reaching 540℃.

3. The on-site testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures according to claim 2, characterized in that, It also includes a comparison module, which is electrically connected to the equivalent correction module. The comparison module is used to compare the equivalent thermal resistance of the coating under standard conditions with the input equivalent thermal resistance of the coating.

4. The on-site testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures according to claim 1, characterized in that, The furnace body (1) has a first opening (6) on both the top and bottom surfaces, and the two first openings (6) are arranged correspondingly. A second opening (14) is opened at one end of the furnace body (1), and the two first openings (6) are connected to the second opening (14). Two first furnace doors (2) are provided at the first opening (6), and the two first furnace doors (2) are arranged opposite to each other and adapted to the first opening (6). Two second furnace doors (10) are provided at the second opening (14), and the two second furnace doors (10) are arranged opposite to each other and adapted to the second opening (14).

5. The on-site testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures according to claim 4, characterized in that, Two first furnace doors (2) are respectively located on two opposite sides of the first opening (6). The first furnace doors (2) are hinged to the furnace body (1) by multiple first hinges (3). The first hinges (3) are located on the outer side wall of the furnace body (1). Two first stops (4) are rotatably connected to the outer side wall of the furnace body (1). The two first stops (4) are symmetrically arranged with the two first furnace doors (2).

6. The on-site testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures according to claim 4, characterized in that, Each of the two first furnace doors (2) has a sliding groove (17) on one side opposite to the other. The two sliding grooves (17) are arranged opposite to each other. One end of one of the sliding grooves (17) passes through the first furnace door (2) and communicates with the other sliding groove (17). Slide rails are fixed on the two opposite side walls of the sliding grooves (17). The two slide rails are arranged parallel and symmetrically. The slide rails are slidably connected in the slots. The slots are opened on the two opposite sides of the sliding cover (5). The sliding cover (5) is detachably connected to the first furnace door (2).

7. The on-site testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures according to claim 4, characterized in that, Two second furnace doors (10) are respectively located on two opposite sides of the second opening (14). The second furnace doors (10) are hinged to the furnace body (1) by multiple second hinges (13). The second hinges (13) are located on the outer side wall of the furnace body (1). One of the second furnace doors (10) is rotatably connected to a stop bar (11) on the side outside the furnace body (1). The other second furnace door (10) is fixedly connected to a locking block (12) on the side outside the furnace body (1). The locking block (12) and the stop bar (11) are detachably connected.

8. The on-site testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures according to claim 1, characterized in that, The bottom surface of the furnace body (1) is fixedly connected to a frame (9), and rollers (16) are installed at the four corners of the bottom surface of the frame (9).

9. The on-site testing device for the fire resistance performance of intumescent fire-retardant coatings for steel structures according to claim 1, characterized in that, The furnace body (1) has observation ports (8) on its two opposite side walls.

10. A device for on-site testing of the fire resistance performance of intumescent fire-retardant coatings for steel structures according to claim 8, characterized in that, An oxygen cylinder (15) and a gas cylinder (18) are fixedly installed on the frame (9), and both the oxygen cylinder (15) and the gas cylinder (18) are connected to the furnace body (1).

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