Fire simulator and evaporation rate regulation and control method

Abstract

The invention relates to a fire simulator and an evaporation rate regulation and control method. The fire simulator comprises an evaporation pond and a steam outlet; the hydraulic assembly is arranged at the bottom of the evaporation pond and comprises a top plate and a hydraulic column connected with the top plate; the porous medium module is arranged in the evaporation pond, a liquid fuel layer is formed between the punching supporting plate and the top plate, and the porous infiltration layer is located on the side, away from the top plate, of the punching supporting plate. The radiation type heater is positioned above the porous infiltration layer; the first temperature sensor is located in the porous medium module; the mass sensor is arranged at the bottom of the outer side of the evaporation pond; the shooting module is located on the outer side of the evaporation pond and detects the liquid level parameter of the porous infiltration layer, and the liquid level parameter is the interval height between an evaporation interface in the porous infiltration layer and the top plate; and the processing module controls the jacking pressure of the hydraulic column and the incident radiation flux of the radiation type heater according to the temperature parameter, the liquid level parameter, the quality parameter and the target evaporation rate until the porous infiltration layer evaporates the liquid fuel according to the target value.

Description

Technical Field

[0001] The present disclosure relates to the technical field of fire simulation, and in particular to a fire simulator and a method for controlling an evaporation rate. Background Art

[0002] Some related technologies use a room-temperature gaseous fuel (such as methane) as a fuel source, adjusting the gas supply rate to be equivalent to the evaporation rate of the liquid fuel to study the characteristics of liquid fuel fires. However, the chemical composition of liquid fuels at room temperature differs from that of gaseous fuels at room temperature, resulting in discrepancies between the research results and actual liquid fires, and the fire characteristics are less accurate. Summary of the Invention

[0003] The present disclosure provides a fire simulator and a method for controlling an evaporation rate to address deficiencies in related technologies.

[0004] According to a first aspect of an embodiment of the present disclosure, there is provided a fire simulator, comprising:

[0005] an evaporation pond, the evaporation pond including a steam outlet;

[0006] A hydraulic assembly, the hydraulic assembly being arranged at the bottom of the evaporation pond, the hydraulic assembly comprising a top plate and a hydraulic column connected to the top plate;

[0007] A porous medium module, the porous medium module being disposed in the evaporation tank, the porous medium module comprising a perforated support plate, a porous infiltration layer, and a liquid fuel layer, the liquid fuel layer being formed between the perforated support plate and the top plate, the porous infiltration layer being disposed on a side of the perforated support plate facing away from the top plate;

[0008] a radiant heater, the radiant heater being located above the porous infiltration layer;

[0009] a first temperature sensor, the first temperature sensor being disposed in the porous medium module;

[0010] A mass sensor, the mass sensor being arranged at the outer bottom of the evaporation pond;

[0011] a photographing module, the photographing module being located outside the evaporation pool and being used to detect a liquid level parameter of the porous infiltration layer, the liquid level parameter being a height between an evaporation interface in the porous infiltration layer and the top plate;

[0012] and a processing module, wherein the processing module controls the lifting pressure of the hydraulic column and the incident radiation flux of the radiant heater according to the temperature parameter of the first temperature sensor, the liquid level parameter, the mass parameter of the mass sensor, and the target evaporation rate, until the porous infiltration layer evaporates the liquid fuel at a target value, and the difference between the target value and the target evaporation rate is less than or equal to a preset threshold.

[0013] Optionally, the processing module optimizes and iterates to obtain the lifting pressure and the incident radiation flux according to the temperature parameter, the liquid level parameter, and the quality parameter, based on the evaporation rate control equation of the porous medium module, the objective function in the evaporation rate control process, and the constraints in the evaporation rate control process, until the objective function is minimized in this iterative cycle, where the objective function is the difference between the target evaporation rate and the actual evaporation rate;

[0014] adjusting an output parameter of the hydraulic column according to the lifting pressure, and adjusting an output parameter of the radiant heater according to the incident radiation flux;

[0015] The above steps are repeated until the objective function reaches the target value after multiple iterations.

[0016] Optionally, also include:

[0017] A porous temperature-controlled electric heating plate, the porous temperature-controlled electric heating plate being located above the radiant heater, the temperature of the porous temperature-controlled electric heating plate being greater than the boiling point of the liquid fuel;

[0018] An igniter is arranged near the steam outlet.

[0019] Optionally, at least one of the following is also included:

[0020] a second temperature sensor, located outside the evaporation pool and configured to detect flame temperature;

[0021] A gas concentration sensor is located outside the evaporation pool and is used to detect the gas concentration around the flame;

[0022] A radiation heat flux sensor is located outside the evaporation pool and is used to detect the radiation heat around the flame.

[0023] Optionally, the evaporation pool includes a valve, and the valve is used to control the connection and disconnection between the liquid fuel layer and the outside;

[0024] The fire simulator further includes a peristaltic pump and a fuel supply assembly, wherein the peristaltic pump is connected to the fuel supply assembly and the valve.

[0025] Optionally, also include:

[0026] an interaction unit, the interaction unit being electrically connected to the processing module;

[0027] a data acquisition module, the data acquisition module being electrically connected to the first temperature sensor, the photographing module, the mass sensor, and the interaction unit, respectively;

[0028] The processing module obtains the temperature parameter, the liquid level parameter, and the quality parameter through the interaction unit.

[0029] According to a second aspect of an embodiment of the present disclosure, a method for controlling an evaporation rate is provided, which is applied to a fire simulator as described in any of the aforementioned embodiments, comprising:

[0030] Acquiring temperature parameters, liquid level parameters, and quality parameters, wherein the quality parameters are used to calculate a real-time evaporation rate of the porous infiltration layer;

[0031] Based on the temperature parameter, the liquid level parameter, the mass parameter of the mass sensor, and the target evaporation rate, the lifting pressure of the hydraulic column and the incident radiation flux of the radiant heater are controlled until the porous infiltration layer evaporates the liquid fuel at a target value, and the difference between the target value and the target evaporation rate is less than or equal to a preset threshold.

[0032] Optionally, controlling the lifting pressure of the hydraulic column and the incident radiation flux of the radiant heater according to the temperature parameter, the liquid level parameter, the mass parameter of the mass sensor, and the target evaporation rate until the porous infiltration layer evaporates the liquid fuel at the target evaporation rate includes:

[0033] According to the temperature parameter, the liquid level parameter, and the quality parameter, based on the evaporation rate control equation of the porous medium module, the objective function in the evaporation rate control process, and the constraints in the evaporation rate control process, optimizing iteratively to obtain the lifting pressure and the incident radiation flux until the objective function in this cycle is minimized, wherein the objective function is the difference between the target evaporation rate and the actual evaporation rate;

[0034] adjusting an output parameter of the hydraulic column according to the lifting pressure, and adjusting an output parameter of the radiant heater according to the incident radiation flux;

[0035] The above steps are repeated until the objective function is minimized in multiple cycles.

[0036] Optionally, the control equation is:

[0037]

[0038]

[0039]

[0040]

[0041] T 计算域下表面 =T 环境 (1.5)

[0042]

[0043]

[0044]

[0045]

[0046] Among them, α 气-固 is the known value of the thermal diffusivity in the region from the evaporation interface of the porous infiltrated layer to the upper surface of the porous infiltrated layer;

[0047] T is the temperature value of any grid after the porous medium module is meshed along the longitudinal direction;

[0048] q rad,in is the incident radiation flux of the radiant heater, is the solved value;

[0049] is the gradient value of the incident radiation flux along the longitudinal direction in the porous medium module;

[0050] d is the particle size of the porous infiltrated layer;

[0051] z is the longitudinal height of any grid after the porous medium module is meshed along the longitudinal direction;

[0052] α 液-固 is the known value of the thermal diffusivity in the region from the evaporation interface of the porous infiltrated layer to the lower surface of the porous infiltrated layer;

[0053] L is the known latent heat of vaporization per unit mass of liquid fuel;

[0054] is the actual evaporation rate;

[0055] α 液 is the known value of the thermal diffusivity of the liquid fuel in the liquid fuel cavity;

[0056] k 气-固 is the known thermal conductivity from the evaporation interface of the porous wetting layer to the upper surface of the computational domain;

[0057] ε is the emissivity of the porous medium infiltrated layer;

[0058] σ is the Stefan-Boltzmann constant;

[0059] h is the convective heat transfer coefficient between the porous infiltrated layer and the ambient steam;

[0060] T 蒸汽 is the temperature of the surrounding steam;

[0061] T 环境 is the temperature value of the atmospheric environment below the top plate;

[0062] T k+1 , is the temperature state vector of the k+1th time step;

[0063] T k is the temperature state vector at the kth time step;

[0064] Δt is the time step between adjacent time steps;

[0065] A is the heat conduction matrix;

[0066] B is the interface tracking matrix, which takes 1 only at the intersection of the evaporation interface of the porous infiltrated layer and the main diagonal of the matrix, and takes 0 at other locations;

[0067] is the evaporation rate vector at the Kth time step;

[0068] k 液-固 is the known thermal conductivity from the evaporation interface of the porous infiltrated layer to the lower surface of the computational domain;

[0069] h 蒸发界面,k+1 is the height of the evaporation interface in the porous wetting layer at the k+1th time step;

[0070] h 蒸发界面,k+1 is the height of the evaporation interface in the porous wetting layer at the kth time step;

[0071] μ is the dynamic viscosity of the liquid fuel;

[0072] P 外压,k is the lifting pressure of the hydraulic column at the kth time step;

[0073] The objective function is:

[0074]

[0075] Wherein, J is the difference between the actual evaporation rate and the target evaporation rate;

[0076] N p To predict the time domain length;

[0077] is the target evaporation rate;

[0078] is the evaporation rate value calculated for the i-th time step;

[0079] The constraints include state constraints and input constraints. The state constraints are:

[0080] T min ≤T k ≤T max

[0081] The input constraints are:

[0082] 0≤q rad,in ≤q max

[0083] 0≤P 外压,k ≤P max

[0084] Among them, T max is the upper limit of safe temperature;

[0085] T min It is the lower limit of safe temperature;

[0086] q max For radiation constraints, do not exceed the upper limit of the radiant heater;

[0087] P 外压,k The pressure constraint is to not exceed the maximum top lift pressure of the hydraulic column.

[0088] According to a third aspect of an embodiment of the present disclosure, a computer-readable storage medium is provided, on which computer instructions are stored. When the instructions are executed by a processor, the steps of any of the methods described above are implemented.

[0089] The technical solutions provided by the embodiments of the present disclosure may have the following beneficial effects:

[0090] It can be seen from the above embodiments that the present disclosure involves a porous infiltration layer as the evaporation source of liquid fuel, and adjusts the evaporation rate of the porous infiltration layer to achieve the target evaporation rate by changing the incident radiation flux of the radiant heater and the lifting pressure of the hydraulic column. This can achieve the regulation of the evaporation rate of liquid fuel in a large range, realize the decoupling between the combustion scale and the evaporation rate, and provide technical support for studying the smoke production behavior of liquid fuel fires under different evaporation rates.

[0091] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0093] Figure 1 The figure is a schematic structural diagram of a fire simulator according to an exemplary embodiment.

[0094] Figure 2 is a schematic diagram of a porous media module according to an exemplary embodiment.

[0095] Figure 3 The figure is a schematic structural diagram of another fire simulator according to an exemplary embodiment.

[0096] Figure 4 FIG. 1 is a structural diagram of another fire simulator according to an exemplary embodiment.

[0097] Figure 5 The figure is a flow chart showing a method for controlling an evaporation rate according to an exemplary embodiment.

[0098] Figure 6 The figure is a flow chart showing another method for controlling evaporation rate according to an exemplary embodiment.

[0099] Figure 7 It is a debugging curve diagram showing a process of regulating and controlling an evaporation rate according to an exemplary embodiment.

[0100] Figure 8 The figure is a block diagram of a device for controlling an evaporation rate according to an exemplary embodiment. DETAILED DESCRIPTION

[0101] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0102] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0103] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining."

[0104] Figure 1 FIG. 1 is a structural diagram of a fire simulator according to an exemplary embodiment. Figure 1 As shown, the fire simulator may include an evaporation pool 1, a hydraulic assembly 2, a porous medium module 3, and a radiant heater 4. The evaporation pool 1 is provided with an evaporation chamber and a steam outlet. The hydraulic assembly 2, the porous medium module 3, and the radiant heater 4 may all be disposed within the evaporation chamber. The hydraulic assembly 2 is disposed at the bottom of the evaporation pool 1 and includes a top plate 21 and a hydraulic column 22 connected thereto. The top plate 21 is tightly sealed against the inner ring of the evaporation chamber. The hydraulic column 22 is lifted to propel the top plate 21 back and forth within the evaporation chamber.

[0105] The porous medium module 3 includes a perforated support plate 31, a porous infiltration layer 32, and a liquid fuel layer 33. The liquid fuel layer 33 is formed between the perforated support plate 31 and the top plate 21. The porous infiltration layer 32 is arranged on the side of the perforated support plate 31 facing away from the top plate 21. The liquid fuel layer 33 can be filled with liquid fuel. Under the action of the hydraulic assembly 2, the liquid fuel can infiltrate into the porous infiltration layer 32 through the perforated support plate 31. By adjusting the lifting pressure of the hydraulic column 22, the spacing between the top plate 21 and the perforated support plate 31 can be adjusted, thereby adjusting the infiltration height of the liquid fuel in the porous infiltration layer 32. The radiant heater 4 can be arranged above the porous infiltration layer 32, outputting radiation to the porous infiltration layer 32 through the radiant heater 4, thereby transferring heat to the porous infiltration layer 32, causing the liquid fuel immersed in the inner layer 32 of the porous machine to evaporate, and the evaporated gaseous fuel is discharged through the steam outlet. For example, the radiant heater 4 may include a conical radiant heater. The porous infiltration layer 32 may be made of materials with stable physical and chemical properties, such as glass beads and quartz sand, with uniform particle sizes.

[0106] Furthermore, the fire simulator also includes a first temperature sensor 5, a mass sensor 6, and a camera module 7. The first temperature sensor 5 can be located within the porous medium module 3. There can be one or more first temperature sensors 5, and multiple first temperature sensors 5 can be arranged longitudinally along the evaporation pool 1 to measure temperatures at different locations. The mass sensor 6 is located at the outer bottom of the evaporation pool 1. The mass sensor 6 can detect the total weight of the evaporation pool 1 and its components. The real-time evaporation rate of the porous infiltration layer 32 can then be calculated based on the mass difference over time.

[0107] The camera module 7 is located outside the evaporation pool 1. The camera module 7 can detect the liquid level parameter of the porous infiltration layer 32. The liquid level parameter is the height between the evaporation interface in the porous infiltration layer 32 and the top plate 21, that is, the height of the evaporation interface. Figure 1 The middle is the height between the end point of the liquid fuel infiltration in the porous infiltration layer 32 and the top. The fire simulator also includes a processing module 8, which controls the lifting pressure of the hydraulic column 22 and the incident radiation flux of the radiant heater 4 based on the temperature parameter of the first temperature sensor 5, the liquid level parameter, the mass parameter of the mass sensor 6, and the target evaporation rate. The processing module 8 then adjusts the lifting pressure of the hydraulic column 22 to change the liquid level parameter, and adjusts the incident radiation flux to change the amount of heat received by the porous infiltration layer 32, thereby achieving the purpose of adjusting the evaporation rate of the porous infiltration layer 32, until the porous infiltration layer 32 evaporates the liquid fuel at the target value, and the difference between the target value and the target evaporation rate is less than or equal to a preset threshold.

[0108] Based on the technical solution disclosed herein, by using a porous infiltration layer 32 as the evaporation source of the liquid fuel, and by varying the incident radiation flux of the radiant heater and the lifting pressure of the hydraulic column 22, the evaporation rate of the porous infiltration layer 32 is adjusted to achieve a target evaporation rate. This allows for regulation of the evaporation rate of the liquid fuel over a wide range, achieving decoupling between the combustion scale and the evaporation rate, and providing technical support for studying the smoke production behavior of liquid fuel fires at different evaporation rates. For example, this can be used to study the flame behavior and smoke production characteristics in scenarios with high initial momentum liquid pool fires (corresponding to high evaporation rates) or nearly extinguished liquid pool fires (corresponding to low evaporation rates).

[0109] The processing module can optimize and iterate the lifting pressure of the hydraulic column 22 and the incident radiation flux of the radiant heater 4 based on the temperature parameters, liquid level parameters, and quality parameters, the evaporation rate control equation of the porous medium module 3, the objective function in the evaporation rate control process, and the constraints in the evaporation rate control process, until the objective function in this iterative cycle is minimized. The objective function is the difference between the target evaporation rate and the actual evaporation rate. The output parameters of the hydraulic column 22 are then adjusted according to the lifting pressure, and the output parameters of the radiant heater 4 are adjusted according to the incident radiation flux. Based on the adjustments of the hydraulic column 22 and the radiant heater 4, the evaporation interface of the porous infiltrating layer 32 and the heating of the porous infiltrating layer 32 both respond to changes, and the actual evaporation rate of the porous infiltrating layer 32 changes. Based on this change, the temperature parameters, quality parameters, and liquid level parameters can be obtained again by the first temperature sensor 4, the quality sensor 5, and the imaging module 6, respectively, for calculation until the objective function reaches the target value after multiple iterative cycles. The target value is the minimum threshold of the acceptable difference between the actual evaporation rate and the target evaporation rate.

[0110] In this embodiment, the evaporation rate control equation of the porous medium module 3 is as follows:

[0111]

[0112]

[0113]

[0114]

[0115] T 计算域下表面 =T 环境 (1.5)

[0116]

[0117] Among them, Figure 2 As shown, formula (1.1) is the energy conservation equation for the area from the evaporation interface in the porous infiltration layer 32 to the upper surface of the porous infiltration layer 32 (i.e., the upper surface of the calculation domain), formula (1.2) is the energy conservation equation for the area from the evaporation interface in the porous infiltration layer 32 to the lower surface of the porous infiltration layer 32, formula (1.3) is the energy conservation equation for the liquid fuel layer 33, formula (1.4) is the boundary condition equation for the upper surface position of the porous infiltration layer 32, formula (1.5) is the boundary condition equation for the lower surface of the porous medium module 3 (i.e., the lower surface of the calculation domain), and formula (1.6) is the calculation formula for the transmission value of the incident radiation flux along the longitudinal direction in the porous medium module 3.

[0118] α 气-固is a known value of the thermal diffusivity in the region from the evaporation interface of the porous infiltration layer 32 to the upper surface of the porous infiltration layer 32;

[0119] T is the temperature value of any grid after the porous medium module 3 is gridded along the longitudinal direction;

[0120] q rad,in is the incident radiation flux of the radiant heater, is the solved value;

[0121] is the gradient value of the incident radiation flux along the longitudinal direction in the porous medium module 3;

[0122] d is the particle size of the porous infiltration layer 32;

[0123] z is the longitudinal height of any grid after the porous medium module 3 is gridded along the longitudinal direction;

[0124] α 液-固 is the known value of the thermal diffusivity in the region from the evaporation interface of the porous infiltration layer to the lower surface of the porous infiltration layer 32;

[0125] L is the known latent heat of vaporization per unit mass of liquid fuel;

[0126] is the actual evaporation rate;

[0127] α 液 is the known value of the thermal diffusivity of the liquid fuel in the liquid fuel cavity;

[0128] k 气-固 is the known thermal conductivity from the evaporation interface of the porous wetting layer 32 to the upper surface of the computational domain;

[0129] ε is the emissivity of the porous medium infiltrated layer;

[0130] σ is the Stefan-Boltzmann constant;

[0131] h is the convective heat transfer coefficient between the porous infiltrated layer 32 and the ambient steam;

[0132] T 蒸汽 is the temperature of the surrounding steam;

[0133] T 环境 is the temperature value of the atmospheric environment below the top plate.

[0134] Use the finite element method to discretize the above energy conservation equation and boundary condition equation to form the corresponding discrete state equation:

[0135]

[0136] Among them, Figure 2 As shown, T k+1, is the temperature state vector of the k+1th time step;

[0137] T k is the temperature state vector at the kth time step;

[0138] Δt is the time step between adjacent time steps;

[0139] A is the heat conduction matrix, which can be obtained by discretizing Equations (1.1) to (1.5) using the finite element method;

[0140] B is the interface tracking matrix, which takes 1 only at the intersection of the evaporation interface grid position of the porous infiltration layer 32 and the main diagonal position of the matrix, and is 0 at other positions;

[0141] is the evaporation rate vector at the Kth time step, which can be calculated using formula (1.8).

[0142]

[0143] During the evaporation process, the evaporation interface position of the porous wetting layer 32 can be calculated using formula (1.9):

[0144]

[0145] By calculating the position of the evaporation interface, the energy conservation equations for the areas corresponding to Equations (1.1) and (1.2) can be dynamically updated.

[0146] Among them, k 液-固 is the known thermal conductivity from the evaporation interface of the porous infiltrated layer to the lower surface of the computational domain;

[0147] h 蒸发界面,k+1 is the height of the evaporation interface in the porous wetting layer 32 at the k+1 time step;

[0148] h 蒸发界面,k is the height of the evaporation interface in the porous wetting layer at the kth time step;

[0149] μ is the dynamic viscosity of the liquid fuel;

[0150] P 外压,k is the lifting pressure of the hydraulic column at the kth time step;

[0151] ρ 燃料 is the density of liquid fuel.

[0152] The objective function is:

[0153]

[0154] Wherein, J is the difference between the actual evaporation rate and the target evaporation rate;

[0155] N p To predict the time domain length;

[0156] is the target evaporation rate;

[0157] The evaporation rate value calculated for the i-th time step.

[0158] The constraints are:

[0159] State constraint: T min ≤T k ≤T max (1.11)

[0160] Input constraint: 0≤q rad,in ≤q max (1.12)

[0161] 0≤P 外压,k ≤P max (1.13)

[0162] Among them, T max is the upper limit of safe temperature;

[0163] T min It is the lower limit of safe temperature;

[0164] q max For radiation constraints, do not exceed the upper limit of the radiant heater;

[0165] P max For pressure constraints, the maximum top lift pressure of the hydraulic column shall not be exceeded.

[0166] In this embodiment, the objective function (Equation (1.10)), constraints (Equations (1.11)-(1.13)), and discrete state equations (Equations (1.7)-(1.9)) are solved using a model predictive control algorithm. Furthermore, after inputting temperature, mass, and liquid level parameters, the outputs are the lift pressure and incident radiation flux.

[0167] In some embodiments, before implementing the above-mentioned control step, the evaporation interface in the porous infiltration layer 32 can be heated to the boiling point of the fuel by the radiant heater 4, thereby ensuring that the heat radiated to the hot porous infiltration layer 32 by the subsequent radiant heater 4 is used to evaporate the liquid fuel. The evaporation rate of the porous infiltration layer 32 is completely controlled by heat transfer and does not need to be used to heat the porous infiltration layer 32 itself, thereby ensuring that the control of the evaporation rate is more stable.

[0168] In some embodiments, the fire simulator further includes a porous temperature-controlled electric heating plate 9 and an igniter 10. The porous temperature-controlled electric heating plate 9 is located above the radiant heater 4, and the temperature control temperature of the porous temperature-controlled electric heating plate 9 is greater than the boiling point of the liquid fuel, thereby preventing the steam flowing out of the porous infiltration layer 32 from liquefying. The igniter 10 can be set close to the steam outlet to ignite the steam at the steam outlet when the porous infiltration layer 32 evaporates at a target evaporation rate to simulate a fire. The igniter 10 can be controlled by the user, or the igniter 10 can be electrically connected to the processing module 8, and the processing module 8 can control the ignition of the igniter 10 when the objective function reaches the target value after multiple iterative cycles.

[0169] In some embodiments, as Figure 1 and Figure 3 As shown, the fire simulator may further include a second temperature sensor 11, which may be located outside the evaporation pool 1 and may detect the flame temperature through the second temperature sensor 11 to obtain flame characteristics at a target evaporation rate. The second temperature sensor 11 may be electrically connected to the processing module 8, which may collect flame characteristics based on the temperature signal fed back by the second temperature sensor 11. In some embodiments, the fire simulator may further include a gas concentration sensor 12, which may be located outside the evaporation pool 1 and may detect the gas concentration surrounding the flame to obtain flame characteristics at a target evaporation rate. The gas concentration sensor 12 may be electrically connected to the processing module 8, which may collect flame characteristics based on the concentration signal fed back by the gas concentration sensor 12. In some embodiments, the fire simulator may further include a radiation heat flux sensor 13, which may be located outside the evaporation pool 1 and may detect the radiant heat surrounding the flame to obtain flame characteristics at a target evaporation rate. The radiation heat flux sensor 13 may be electrically connected to the processing module 8, which may collect flame characteristics based on the heat signal fed back by the radiation heat flux sensor 13. In the same embodiment, the fire simulator may include one or more of the second temperature sensor 11, the gas concentration sensor 12, and the radiation heat flux sensor 13, and may integrate the detection data of multiple sensors to understand the flame behavior characteristics.

[0170] In some embodiments, as Figure 3 As shown, the evaporation pool 1 also includes a valve (not shown), which is used to control the connection and disconnection of the liquid fuel layer 33 with the outside. The fire simulator can also include a peristaltic pump 14 and a fuel supply assembly 15. The peristaltic pump 14 connects the fuel supply assembly 15 and the valve, so that the filtered liquid fuel can be filled into the liquid fuel layer 33 through the peristaltic pump 14, so as to facilitate pumping sufficient fuel into the porous medium module 3 before the experiment begins.

[0171] In some embodiments, as Figure 4 As shown, the fire simulator also includes a data acquisition module 16 and an interaction unit 17. The interaction unit 17 is electrically connected to the processing module 8. The data acquisition module 16 is also electrically connected to the first temperature sensor 5, the mass sensor 6, the camera module 7, and the interaction unit 17. Based on this, the detection parameters of the first temperature sensor 5, the mass sensor 6, and the camera module 7 can be fed back to the interaction unit 17, and the processing module 8 can obtain temperature parameters, liquid level parameters, and quality parameters through the interaction unit 17. The interaction unit 17 also includes a display area and a virtual key area within the display area. The display area can display data collected by the data acquisition module 16, and the virtual key area can be used to input a target evaporation rate, so that the processing module 8 can obtain the target evaporation rate input by the user.

[0172] Figure 5 FIG. 1 is a flow chart showing a method for controlling an evaporation rate according to an exemplary embodiment. Figure 5 As shown, the method is applied to the fire simulator described in any of the above embodiments and may include the following steps:

[0173] In step 501, a temperature parameter, a liquid level parameter, and a quality parameter are acquired. The quality parameter is used to calculate a real-time evaporation rate of the porous infiltration layer.

[0174] In this embodiment, the temperature parameter can be detected by the first temperature sensor, the liquid level parameter can be collected by the shooting module, and the quality parameter can be collected by the quality sensor. The real-time evaporation rate of the porous infiltration layer 32 can be calculated based on the difference between two adjacent quality parameters and the interval time.

[0175] In step 502, the lifting pressure of the hydraulic column and the incident radiation flux of the radiant heater are controlled according to the temperature parameter, the liquid level parameter, the mass parameter of the mass sensor, and the target evaporation rate until the porous infiltration layer evaporates the liquid fuel at a target value.

[0176] In this embodiment, the lifting pressure of the hydraulic column 22 and the incident radiation flux of the radiant heater 4 can be calculated through the temperature parameters, liquid level parameters, mass parameters of the mass sensor and the target evaporation rate, and then regulated into electrical signals to control the hydraulic column to adjust the lifting pressure and control the radiant heater 4 to adjust the incident radiation flux until the porous infiltration layer 32 evaporates the liquid fuel at a target value, and the difference between the target value and the target evaporation rate is less than or equal to a preset threshold.

[0177] Based on the technical solution disclosed in the present invention, by involving the porous infiltration layer 32 as the evaporation source of the liquid fuel, and by changing the incident radiation flux of the radiant heater and the lifting pressure of the hydraulic column 22, the evaporation rate of the porous infiltration layer 32 is adjusted to reach the target evaporation rate. This can realize the regulation of the evaporation rate of the liquid fuel in a large range, achieve the decoupling between the combustion scale and the evaporation rate, and provide technical support for studying the smoke production behavior of liquid fuel fires under different evaporation rates.

[0178] In order to elaborate on the above embodiment, Figure 6 As shown in FIG, a flow chart of another method for regulating evaporation rate is provided, as shown in FIG. Figure 6 As shown, the control method comprises the following steps:

[0179] In step 601, temperature parameters, liquid level parameters, quality parameters and target evaporation rate are obtained.

[0180] In step 602, the real-time evaporation rate is calculated based on the quality parameter.

[0181] In this embodiment, the real-time evaporation rate of the porous wetting layer 32 may be calculated based on the quality parameters collected during the previous cycle, the quality parameters collected during the current cycle, and the interval between the two cycles.

[0182] In step 603, based on the control equation, the objective function and the constraint conditions, the optimization iteration is performed to obtain the lifting pressure and the incident radiation flux.

[0183] The specific real-time method in this embodiment can refer to the above embodiment and will not be described again here.

[0184] In step 604, control information is output based on the lifting pressure and incident radiation flux obtained through iterative optimization.

[0185] In this embodiment, the lifting pressure and the incident radiation flux may be modulated into an electrical signal, and the control information may be output.

[0186] In step 605 , the hydraulic column 22 and the radiant heater 4 are regulated based on the control information.

[0187] In this embodiment, control information is sent to the hydraulic column 22 and the radiant heater 4 respectively. The hydraulic column responds to control the longitudinal movement of the top plate along the evaporation pool 1, and the radiant heater 4 responds to adjust the amount of heat that the porous infiltration layer 32 can receive, thereby adjusting the evaporation rate of the porous infiltration layer 32.

[0188] In step 606, it is determined whether the objective function has reached the target value.

[0189] In this embodiment, the objective function is the difference between the target evaporation rate and the actual evaporation rate. In a single cycle, the objective function may reach the target value or may be greater than the target value. When the objective function is greater than the target value, step 601 is executed to enter the next cycle. When the objective function is less than or equal to the target value, the igniter 10 can be controlled to ignite, or the interactive unit 17 can be controlled to display an ignition prompt information, and the user manually ignites after understanding the ignition prompt information.

[0190] In step 607, time is counted.

[0191] In step 608 , ignition is initiated.

[0192] In step 609, it is determined whether the interval time has been reached.

[0193] In this embodiment, after the interval time is reached, step 601 may be executed to enter the next cycle; if the interval time is not reached, step 607 may be executed.

[0194] For example, Figure 7 As shown, taking the target evaporation rate of 0.045 g / s as an example, after the processing module 8 executes the above steps 601-609 until the actual evaporation rate approaches the target evaporation rate of 0.045 g / s, the above control process can be terminated, and the ignition can be controlled or the user can be prompted to ignite.

[0195] Corresponding to the aforementioned embodiments of the control method, the present disclosure also provides embodiments of a control device.

[0196] Figure 8 FIG. 1 is a block diagram of a device for controlling evaporation rate according to an exemplary embodiment. Figure 8 The device includes an acquisition module 81 and a control module 82, wherein:

[0197] An acquisition module 81 acquires temperature parameters, liquid level parameters, and quality parameters, wherein the quality parameters are used to calculate a real-time evaporation rate of the porous infiltration layer;

[0198] The control module 82 controls the lifting pressure of the hydraulic column and the incident radiation flux of the radiant heater according to the temperature parameter, the liquid level parameter, the mass parameter of the mass sensor, and the target evaporation rate until the porous infiltration layer evaporates the liquid fuel at a target value, and the difference between the target value and the target evaporation rate is less than or equal to a preset threshold.

[0199] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0200] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the partial description of the method embodiments. The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the disclosed solution. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0201] Accordingly, the present disclosure also provides a terminal, which includes a memory and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by one or more processors, and the one or more programs include instructions for performing the following operations: obtaining temperature parameters, liquid level parameters and quality parameters, and the quality parameters are used to calculate the real-time evaporation rate of the porous infiltration layer; controlling the lifting pressure of the hydraulic column and the incident radiation flux of the radiant heater according to the temperature parameters, the liquid level parameters, the quality parameters of the mass sensor and the target evaporation rate, until the porous infiltration layer evaporates the liquid fuel at a target value, and the difference between the target value and the target evaporation rate is less than or equal to a preset threshold.

[0202] In an exemplary embodiment, a computer-readable storage medium is further provided, on which computer instructions are stored. When the instructions are executed by a processor, the steps of the method described in any of the aforementioned embodiments are implemented. For example, the computer-readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0203] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0204] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A fire simulator, characterized in that: include: an evaporation pond, the evaporation pond including a steam outlet; A hydraulic assembly, the hydraulic assembly being arranged at the bottom of the evaporation pond, the hydraulic assembly comprising a top plate and a hydraulic column connected to the top plate; A porous medium module, the porous medium module being disposed in the evaporation tank, the porous medium module comprising a perforated support plate, a porous infiltration layer, and a liquid fuel layer, the liquid fuel layer being formed between the perforated support plate and the top plate, the porous infiltration layer being disposed on a side of the perforated support plate facing away from the top plate; a radiant heater, the radiant heater being located above the porous infiltration layer; a first temperature sensor, the first temperature sensor being disposed in the porous medium module; A mass sensor, the mass sensor being arranged at the outer bottom of the evaporation pond; a photographing module, the photographing module being located outside the evaporation pool and being used to detect a liquid level parameter of the porous infiltration layer, the liquid level parameter being a height between an evaporation interface in the porous infiltration layer and the top plate; and a processing module, wherein the processing module controls the lifting pressure of the hydraulic column and the incident radiation flux of the radiant heater according to the temperature parameter of the first temperature sensor, the liquid level parameter, the mass parameter of the mass sensor, and the target evaporation rate, until the porous infiltration layer evaporates the liquid fuel at a target value, and the difference between the target value and the target evaporation rate is less than or equal to a preset threshold.

2. The fire simulator according to claim 1, characterized in that The processing module optimizes and iterates to obtain the lifting pressure and the incident radiation flux according to the temperature parameter, the liquid level parameter, and the quality parameter, based on the evaporation rate control equation of the porous medium module, the objective function in the evaporation rate control process, and the constraints in the evaporation rate control process, until the objective function is minimized in this iterative cycle, where the objective function is the difference between the target evaporation rate and the actual evaporation rate; adjusting an output parameter of the hydraulic column according to the lifting pressure, and adjusting an output parameter of the radiant heater according to the incident radiation flux; The above steps are repeated until the objective function reaches the target value after multiple iterations.

3. The fire simulator according to claim 1, characterized in that: Also includes: A porous temperature-controlled electric heating plate, the porous temperature-controlled electric heating plate being located above the radiant heater, the temperature of the porous temperature-controlled electric heating plate being greater than the boiling point of the liquid fuel; An igniter is arranged near the steam outlet.

4. The fire simulator according to claim 1, characterized in that Also includes at least one of the following: a second temperature sensor, located outside the evaporation pool and configured to detect flame temperature; A gas concentration sensor is located outside the evaporation pool and is used to detect the gas concentration around the flame; A radiation heat flux sensor is located outside the evaporation pool and is used to detect the radiation heat around the flame.

5. The fire simulator according to claim 1, characterized in that: The evaporation pool includes a valve, and the valve is used to control the connection and disconnection between the liquid fuel layer and the outside; The fire simulator further includes a peristaltic pump and a fuel supply assembly, wherein the peristaltic pump is connected to the fuel supply assembly and the valve.

6. The fire simulator according to claim 1, characterized in that: Also includes: an interaction unit, the interaction unit being electrically connected to the processing module; a data acquisition module, the data acquisition module being electrically connected to the first temperature sensor, the photographing module, the mass sensor, and the interaction unit, respectively; The processing module obtains the temperature parameter, the liquid level parameter, and the quality parameter through the interaction unit.

7. A method for regulating evaporation rate, characterized in that: The fire simulator according to any one of claims 1 to 6, characterized in that it comprises: Acquiring temperature parameters, liquid level parameters, and quality parameters, wherein the quality parameters are used to calculate a real-time evaporation rate of the porous infiltration layer; Based on the temperature parameter, the liquid level parameter, the mass parameter of the mass sensor, and the target evaporation rate, the lifting pressure of the hydraulic column and the incident radiation flux of the radiant heater are controlled until the porous infiltration layer evaporates the liquid fuel at a target value, and the difference between the target value and the target evaporation rate is less than or equal to a preset threshold.

8. The control method according to claim 7, characterized in that: The controlling the lifting pressure of the hydraulic column and the incident radiation flux of the radiant heater according to the temperature parameter, the liquid level parameter, the mass parameter of the mass sensor, and the target evaporation rate until the porous infiltration layer evaporates the liquid fuel at the target evaporation rate comprises: According to the temperature parameter, the liquid level parameter, and the quality parameter, based on the evaporation rate control equation of the porous medium module, the objective function in the evaporation rate control process, and the constraints in the evaporation rate control process, optimizing iteratively to obtain the lifting pressure and the incident radiation flux until the objective function in this cycle is minimized, wherein the objective function is the difference between the target evaporation rate and the actual evaporation rate; adjusting an output parameter of the hydraulic column according to the lifting pressure, and adjusting an output parameter of the radiant heater according to the incident radiation flux; The above steps are repeated until the objective function is minimized in multiple cycles.

9. The control method according to claim 8, characterized in that: The control equation is: T 计算域下表面 =T 环境 (1.5) Among them, α 气-固 is the known value of the thermal diffusivity in the region from the evaporation interface of the porous infiltrated layer to the upper surface of the porous infiltrated layer; T is the temperature value of any grid after the porous medium module is meshed along the longitudinal direction; q rad,in is the incident radiation flux of the radiant heater, is the solved value; is the gradient value of the incident radiation flux along the longitudinal direction in the porous medium module; d is the particle size of the porous infiltrated layer; z is the longitudinal height of any grid after the porous medium module is meshed along the longitudinal direction; α 液-固 is the known value of the thermal diffusivity in the region from the evaporation interface of the porous infiltrated layer to the lower surface of the porous infiltrated layer; L is the known latent heat of vaporization per unit mass of liquid fuel; is the actual evaporation rate; α 液 is the known value of the thermal diffusivity of the liquid fuel in the liquid fuel cavity; k 气-固 is the known thermal conductivity from the evaporation interface of the porous wetting layer to the upper surface of the computational domain; ε is the emissivity of the porous medium infiltrated layer; σ is the Stefan-Boltzmann constant; h is the convective heat transfer coefficient between the porous infiltrated layer and the ambient steam; T 蒸汽 is the temperature of the surrounding steam; T 环境 is the temperature value of the atmospheric environment below the top plate; T k+1 , is the temperature state vector of the k+1th time step; T k is the temperature state vector at the kth time step; Δt is the time step between adjacent time steps; A is the heat conduction matrix; B is the interface tracking matrix, which takes 1 only at the intersection of the evaporation interface of the porous infiltrated layer and the main diagonal of the matrix, and takes 0 at other locations; is the evaporation rate vector at the Kth time step; k 液-固 is the known thermal conductivity from the evaporation interface of the porous infiltrated layer to the lower surface of the computational domain; h 蒸发界面,k+1 is the height of the evaporation interface in the porous wetting layer at the k+1th time step; h 蒸发界面,k+1 is the height of the evaporation interface in the porous wetting layer at the kth time step; μ is the dynamic viscosity of the liquid fuel; P 外压,k is the lifting pressure of the hydraulic column at the kth time step; The objective function is: Wherein, J is the difference between the actual evaporation rate and the target evaporation rate; N p To predict the time domain length; is the target evaporation rate; is the evaporation rate value calculated for the i-th time step; The constraints include state constraints and input constraints. The state constraints are: T min ≤T k ≤T max The input constraints are: 0≤q rad,in ≤q max 0≤P 外压,k ≤P max Among them, T max is the upper limit of safe temperature; T min It is the lower limit of safe temperature; q max For radiation constraints, do not exceed the upper limit of the radiant heater; P max For pressure constraints, the maximum top lift pressure of the hydraulic column shall not be exceeded.

10. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the instruction is executed by a processor, the steps of the method according to any one of claims 7 to 9 are implemented.

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