阅读说明：本技术 无焰燃烧自燃温度测试装置、系统及方法 (Flameless combustion spontaneous combustion temperature testing device, system and method ) 是由 颜蓓蓓 苏红 周生权 陈冠益 程占军 于 2020-07-10 设计创作，主要内容包括：本发明公开了一种无焰燃烧自燃温度测试装置、系统及方法,装置包括测试腔体,其中,测试腔体上设置有进气通道和排气通道,测试腔体内设置有用于判定待测燃气是否自燃的温度感应装置；进气通道嵌入设置有用于喷射待测燃气和氧化剂的喷头,喷头上设置有待测燃气喷口和氧化剂喷口,待测燃气喷口用于连通待测燃气源,氧化剂喷口用于连通氧化剂源；还包括腔体加热装置,用于对测试腔体进行加热,通过喷头实现待测燃气在测试腔体内的无焰燃烧,配合测试腔体内的温度感应装置以及测试腔体外侧的腔体加热装置,可以精准的控制测试腔体内的温度,经过多次试验可以准确的获取待测燃气无焰燃烧的自燃温度。(The invention discloses a device, a system and a method for testing the spontaneous combustion temperature of flameless combustion, wherein the device comprises a testing cavity, an air inlet channel and an air outlet channel are arranged on the testing cavity, and a temperature sensing device for judging whether the gas to be tested is spontaneous combustion or not is arranged in the testing cavity; the air inlet channel is embedded with a nozzle for spraying gas to be detected and oxidant, the nozzle is provided with a gas nozzle to be detected and an oxidant nozzle, the gas nozzle to be detected is used for communicating with a gas source to be detected, and the oxidant nozzle is used for communicating with an oxidant source; the device is characterized by further comprising a cavity heating device, wherein the cavity heating device is used for heating the test cavity, flameless combustion of the gas to be tested in the test cavity is realized through the spray head, the temperature sensing device in the test cavity and the cavity heating device outside the test cavity are matched, the temperature in the test cavity can be accurately controlled, and the spontaneous combustion temperature of the flameless combustion of the gas to be tested can be accurately obtained through multiple tests.)

1. The utility model provides a flameless combustion spontaneous combustion temperature testing arrangement for measure the spontaneous combustion temperature of the gas flameless combustion that awaits measuring under the ordinary pressure, its characterized in that includes:

the testing device comprises a testing cavity, wherein an air inlet channel and an air outlet channel are arranged on the testing cavity, a temperature sensing device used for judging whether the gas to be tested spontaneously combusts or not is arranged in the testing cavity, the air outlet channel is communicated with the external space of the testing cavity, a nozzle used for injecting the gas to be tested and an oxidant is embedded in the air inlet channel, a gas nozzle to be tested and an oxidant nozzle are arranged on the nozzle, the gas nozzle to be tested is used for being communicated with a gas source to be tested, and the oxidant nozzle is used for being communicated with an oxidant source; and

and the cavity heating device is used for heating the test cavity.

2. The flameless combustion autoignition temperature testing device according to claim 1, wherein a preheating device is disposed between the oxidant nozzle and the oxidant source, and the preheating device is configured to preheat the oxidant.

3. The flameless combustion spontaneous combustion temperature testing device of claim 1 or 2, wherein the gas nozzle to be tested is arranged at a central position of the nozzle, the number of the oxidant nozzles is multiple, and the multiple oxidant nozzles are annularly arranged outside the gas nozzle to be tested.

4. The flameless combustion spontaneous combustion temperature test device according to claim 1 or 2, wherein the chamber heating device is a furnace body disposed outside the test chamber.

5. The flameless combustion auto-ignition temperature testing apparatus according to claim 1 or 2, wherein the temperature sensing means comprises a thermocouple.

6. A flameless combustion auto-ignition temperature test system, comprising:

the flameless combustion autoignition temperature testing device according to any one of claims 1 to 5;

a central control unit; and

the first electromagnetic valve and the first flowmeter are arranged between the gas source to be tested and the testing cavity; and

a second solenoid valve and a second flow meter disposed between an oxidant source and the test chamber;

the central control unit is connected with the temperature sensing device and the cavity heating device, and is used for receiving and judging a temperature signal sent by the temperature sensor and sending a temperature judgment result to the cavity heating device; the central control unit is connected with the first flow meter and used for receiving and judging the flow signal sent by the first flow meter and sending a first flow judgment result to the first flow meter; the central control unit is connected with the second flow meter and used for receiving and judging the flow signal sent by the second flow meter and sending a second flow judgment result to the second flow meter.

7. The flameless combustion auto-ignition temperature testing system of claim 6, further comprising:

the gas source to be tested is used for introducing gas to be tested into the testing cavity; and

and the oxidant source is used for introducing an oxidant into the test cavity.

8. The flameless combustion auto-ignition temperature test system according to claim 6 or 7, wherein an electronic device is used as the central control unit for controlling the first solenoid valve, the second solenoid valve, the first flow meter and the second flow meter, and recording and analyzing data measured by the temperature sensing device.

9. A method of testing the flameless combustion auto-ignition temperature using the flameless combustion auto-ignition temperature testing apparatus of any one of claims 1 to 5, comprising:

s1, heating the internal temperature of the testing cavity to a target preset temperature through the cavity heating device, and heating the temperature of the oxidant to be sprayed into the testing cavity to the target preset temperature through the preheating device;

s2, spraying the heated oxidant into the test cavity in a jet flow mode, and executing S3 after the test cavity is filled with the oxidant;

s3, spraying the fuel gas to be tested into the test cavity, recording the temperature change of the temperature sensing device and judging:

s31, if the internal temperature of the testing cavity is in a stable state within y seconds, the fact that the fuel gas to be tested does not reach the spontaneous combustion temperature and burns is indicated, the fuel gas to be tested is firstly stopped being sprayed, then the oxidant is stopped being sprayed, then the fuel gas returns to S1, and the internal temperature of the testing cavity and the heating temperature of the oxidant are increased to a first temperature value on the basis of the target preset temperature;

s32, if the internal temperature of the testing cavity rises suddenly above a second temperature value, it is indicated that the fuel gas to be tested is combusted, after the combustion time lasts at least x seconds, the fuel gas and the oxidant to be tested are simultaneously stopped being sprayed or the fuel gas to be tested is firstly stopped being sprayed, then the oxidant is stopped being sprayed, the testing cavity is waited to be cooled, the step S1 is returned, and the internal temperature of the testing cavity and the heating temperature of the oxidant are reduced by a third temperature value on the basis of the target preset temperature;

s4, repeatedly executing the substeps S31 and S32 of S1, S2, S3 and S3 until the internal temperature of the test chamber and the temperature of the oxidant are heated to (a target preset temperature + m times the first temperature value-n times the third temperature value) deg.c, the gas to be tested is burnt, and the gas to be tested is not burnt when the internal temperature of the test chamber and the temperature of the oxidant are heated to (a target preset temperature + m times the first temperature value- (n +1) times the third temperature value) deg.c, and recording (a target preset temperature + m times the first temperature value-n times the third temperature value) deg.c as the spontaneous combustion temperature of the gas to be tested;

wherein m and n are natural numbers, and the first temperature value is larger than the third temperature value.

10. The method as claimed in claim 9, wherein the fuel gas to be tested comprises a single fuel gas or a mixed fuel gas, and the oxidant comprises air or a diluent gas obtained by mixing air with an inert component or a diluent gas obtained by mixing oxygen with an inert component.

Technical Field

The invention relates to the technical field of gas spontaneous combustion temperature detection, in particular to a device, a system and a method for testing flameless combustion spontaneous combustion temperature.

Background

The spontaneous combustion temperature of the fuel gas is an important index for measuring safety in the processes of production, use, storage and transportation, and is also one of important indexes for judging and evaluating the fire hazard of the fuel gas.

The autoignition temperature is also called as the autoignition temperature, and is the lowest temperature at which a substance burns due to the temperature rise when the rate of heat release from the substance due to an exothermic oxidation reaction is higher than the rate of heat release under specific conditions without the action of an open flame source such as a flame or an electric spark. The auto-ignition temperature of the gas is strongly related to the combustion regime, flow rate, residence time, oxygen concentration and reactor volume.

Flameless combustion (MILD combustion) is a novel clean and efficient combustion technology and has the characteristics of high combustion efficiency and low pollution emission. The technology is realized by forming entrainment by high-speed jet flow of preheated air, and the low oxygen concentration in the furnace is higher than the self-ignition temperature of fuel. One skilled in the art establishes an experiment system for measuring the spontaneous combustion temperature of the mixed gas, and researches the spontaneous combustion temperature of the mixed gas under the initial condition of normal temperature and normal pressure; one skilled in the art discloses a device for testing the spontaneous combustion temperature in pure oxygen, so as to evaluate the risk of spontaneous combustion of combustible gas under the condition of pure oxygen.

In the current research, combustible gas and air (oxidant) to be tested at normal temperature are generally injected into a testing cavity in a traditional mode, the spontaneous combustion temperature is tested by raising the temperature of the testing cavity, and a device and a method for testing the flameless combustion spontaneous combustion temperature are absent. When the technicians in the field study that the fuel gas is applied to flameless combustion, the high air preheating temperature is generally adopted to reach the spontaneous combustion temperature, the accurate control is lacked, and meanwhile, the energy waste is caused. The self-ignition temperature of various fuel gases under the flameless combustion condition cannot be accurately tested.

Disclosure of Invention

Technical problem to be solved

In view of the problem that no suitable testing device can accurately and conveniently test the spontaneous combustion temperature of the flameless combustion of the gas at present, the invention provides the device, the system and the method for testing the spontaneous combustion temperature of the flameless combustion of the gas, and the spontaneous combustion temperature of the flameless combustion of the gas can be conveniently and accurately tested.

(II) technical scheme

The invention provides a flameless combustion spontaneous combustion temperature testing device.

According to an embodiment of the present invention, the flameless combustion autoignition temperature testing device comprises:

the testing device comprises a testing cavity, wherein an air inlet channel and an air outlet channel are arranged on the testing cavity, a temperature sensing device used for judging whether the gas to be tested spontaneously combusts or not is arranged in the testing cavity, the air outlet channel is communicated with the external space of the testing cavity, a nozzle used for injecting the gas to be tested and an oxidant is embedded in the air inlet channel, a gas nozzle to be tested and an oxidant nozzle are arranged on the nozzle, the gas nozzle to be tested is used for being communicated with a gas source to be tested, and the oxidant nozzle is used for being communicated with an oxidant source; and

and the cavity heating device is used for heating the test cavity.

According to an embodiment of the invention, a preheating device is arranged between the oxidant nozzle and the oxidant source, and the preheating device is used for preheating the oxidant.

According to the embodiment of the invention, the gas nozzles to be detected are arranged at the center of the spray head, the number of the oxidant nozzles is multiple, and the multiple oxidant nozzles are annularly arranged on the outer side of the gas nozzles to be detected.

According to an embodiment of the present invention, the chamber heating device is a heating furnace body disposed outside the test chamber.

According to an embodiment of the invention, the temperature sensing means comprises a thermocouple.

The invention also discloses a flameless combustion spontaneous combustion temperature test system, which comprises:

the flameless combustion spontaneous combustion temperature testing device is used for testing the flameless combustion spontaneous combustion temperature;

a central control unit; and

the first electromagnetic valve and the first flowmeter are arranged between the gas source to be tested and the testing cavity; and

a second solenoid valve and a second flow meter disposed between an oxidant source and the test chamber;

the central control unit is connected with the temperature sensing device and the cavity heating device, and is used for receiving and judging a temperature signal sent by the temperature sensor and sending a temperature judgment result to the cavity heating device; the central control unit is connected with the first flow meter and used for receiving and judging the flow signal sent by the first flow meter and sending a first flow judgment result to the first flow meter; the central control unit is connected with the second flow meter and used for receiving and judging the flow signal sent by the second flow meter and sending a second flow judgment result to the second flow meter.

According to an embodiment of the present invention, further comprising:

the gas source to be tested is used for introducing gas to be tested into the testing cavity; and

and the oxidant source is used for introducing an oxidant into the test cavity.

According to the embodiment of the invention, an electronic device is used as the central control unit for controlling the first electromagnetic valve, the second electromagnetic valve, the first flowmeter and the second flowmeter, and recording and analyzing data measured by the temperature sensing device.

The invention also discloses a method for testing the flameless combustion spontaneous combustion temperature by using the flameless combustion spontaneous combustion temperature testing device, which comprises the following steps:

s1, heating the internal temperature of the testing cavity to a target preset temperature through the cavity heating device, and heating the temperature of the oxidant to be sprayed into the testing cavity to the target preset temperature through the preheating device;

s2, spraying the heated oxidant into the test cavity in a jet flow mode, and executing S3 after the test cavity is filled with the oxidant;

s3, spraying the fuel gas to be tested into the test cavity, and recording the temperature change of the temperature sensing device:

s31, if the internal temperature of the testing cavity is in a stable state within y seconds, the fact that the fuel gas to be tested does not reach the spontaneous combustion temperature and burns is indicated, the fuel gas to be tested is firstly stopped being sprayed, then the oxidant is stopped being sprayed, then the step S1 is returned, and the internal temperature of the testing cavity and the heating temperature of the oxidant are increased to a first temperature value on the basis of the target preset temperature;

s32, if the internal temperature of the testing cavity rises suddenly above a second temperature value, it is indicated that the fuel gas to be tested is combusted, after the combustion time lasts at least x seconds, the fuel gas and the oxidant to be tested are simultaneously stopped being sprayed or the fuel gas to be tested is firstly stopped being sprayed, then the oxidant is stopped being sprayed, the testing cavity is waited to be cooled, the step S1 is returned, and the internal temperature of the testing cavity and the heating temperature of the oxidant are reduced by a third temperature value on the basis of the target preset temperature;

s4, repeatedly executing the steps S1, S2, and S3 until the fuel gas to be tested is burned when the internal temperature of the test chamber and the temperature of the oxidant are heated to (a target preset temperature + m times the first temperature value-n times the third temperature value) ° c, and the fuel gas to be tested is not burned when the internal temperature of the test chamber and the temperature of the oxidant are heated to (a target preset temperature + m times the first temperature value- (n +1) times the third temperature value) ° c, and recording (a target preset temperature + m times the first temperature value-n times the third temperature value) ° c as the spontaneous combustion temperature of the fuel gas to be tested;

wherein m and n are natural numbers, and the first temperature value is larger than the third temperature value.

According to the embodiment of the invention, the fuel gas to be measured is single fuel gas or mixed fuel gas, and the oxidant is air or diluent gas with inert components mixed in oxygen.

(III) advantageous effects

The device realizes flameless combustion of the gas to be tested in the test cavity through the spray head, can accurately control the temperature in the test cavity by matching with the thermocouple in the test cavity and the cavity heating device outside the test cavity, and can accurately obtain the spontaneous combustion temperature of the flameless combustion of the gas to be tested through a plurality of tests.

In addition, the preheating device is additionally arranged to preheat the oxidant, so that the influence of the temperature difference between the oxidant and the test cavity on the test result is reduced, and the test accuracy is higher.

Drawings

FIG. 1 is a schematic structural diagram of a flameless combustion auto-ignition temperature testing device provided by an embodiment of the invention;

FIG. 2 is a schematic structural diagram of a nozzle of the flameless combustion auto-ignition temperature testing apparatus provided in the embodiment of the present invention;

FIG. 3 is a flow chart of a flameless combustion auto-ignition temperature test method provided by an embodiment of the invention;

wherein: 1 denotes a test chamber; 2 represents a gas source to be measured; 3 represents an oxidant source; 4 denotes a preheating device; 5 represents a computer; 6 denotes a heating furnace body; 7 denotes an exhaust passage; 8 denotes a first solenoid valve; 9 denotes a first flow meter; 10 denotes a second solenoid valve; 11 denotes a second flow meter; 12 denotes a thermocouple; 13 denotes an oxidant jet; 14 denotes a gas nozzle to be measured; 15 denotes an intake passage; and 16 denotes a spray head.

Detailed Description

In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments.

It is to be understood that such description is merely illustrative and not intended to limit the scope of the present invention. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It may be evident, however, that one or more embodiments may be practiced without these specific details. Furthermore, in the following description, descriptions of well-known technologies are omitted so as to avoid unnecessarily obscuring the concepts of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "comprises" and "comprising," when used herein, specify the presence of stated features, steps, or operations, but do not preclude the presence or addition of one or more other features, steps, or operations.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly formal sense such as "atmospheric" being a standard atmosphere of about 0.1MPa, with a slight difference depending on the measurement, specifically the local equipment or vessel not being subjected to atmospheric pressure and its internal pressure being an atmosphere, calculated as 0.1 MPa.

Fig. 1 schematically shows a structural schematic diagram of a flameless combustion auto-ignition temperature testing device provided by an embodiment of the invention.

As shown in figure 1, the flameless combustion spontaneous combustion temperature testing device comprises a testing cavity 1 and a cavity heating device.

According to an embodiment of the present invention, the testing chamber 1 may be a sealed chamber of a square, spherical or ellipsoidal type.

According to the embodiment of the invention, the test cavity is spherical or ellipsoidal, and the sealing performance and the integrity are better.

According to the embodiment of the invention, the test cavity 1 is provided with the air inlet channel 15 and the air outlet channel 7, the air inlet channel 15 is a channel for the fuel gas to be tested and the oxidant to enter the test cavity, the air outlet channel 7 is communicated with the external space of the test cavity 1, and the air outlet channel 7 can discharge the miscellaneous gas, the waste gas before combustion and the waste gas after combustion in the test cavity 1 out of the test cavity 1.

According to the embodiment of the present invention, the air inlet passage 15 and the air outlet passage 7 are symmetrically disposed at both ends of the test chamber 1.

According to the embodiment of the present invention, the testing chamber 1 is a steel chamber or other high-strength chamber.

According to the embodiment of the invention, the test cavity 1 is provided with the observation window which is made of transparent material, so that the combustion condition of the gas to be tested in the test cavity 1 can be observed from the outer side of the test cavity, and the flow of the gas to be tested and the injected oxidant can be adjusted according to the specific combustion condition of the gas to be tested, thereby ensuring that the gas to be tested is flameless combusted.

According to an embodiment of the invention, the inlet channel 15 is embedded with a nozzle 16 provided for injecting the gas to be measured and the oxidizing agent.

According to the embodiment of the invention, as shown in the structural schematic diagram of the nozzle of the flameless combustion spontaneous combustion temperature testing device shown in fig. 2, the nozzle 16 is provided with a gas nozzle 14 and an oxidant nozzle 13 to be tested.

According to the embodiment of the invention, the gas nozzle 14 to be tested is arranged at the center of the spray head 16, and the oxidant nozzle 13 is arranged at the side of the gas nozzle 14 to be tested.

According to the embodiment of the invention, the number of the oxidant nozzles 13 is multiple, and may be 2, 3, 4, 5 or more, the multiple oxidant nozzles 13 are annularly distributed around the gas nozzle 14 to be measured, and the gas nozzle 14 to be measured is located at the center of the above ring. The structure that a plurality of oxidant spouts 13 annular was arranged can make the oxidant jet get into test cavity 1 in, form the entrainment and with the gas intensive mixing that awaits measuring, form the flameless combustion mode of "mixing earlier, the postcombustion", simultaneously, can prevent that the gas that awaits measuring directly takes place traditional diffusion combustion after meetting the oxidant.

According to the embodiment of the invention, the gas nozzle 14 to be detected is communicated with the gas source 2, and the oxidant nozzle 13 is communicated with the oxidant source 3.

According to the embodiment of the invention, the fuel gas to be measured can be single-component fuel gas or multi-component mixed gas.

According to an embodiment of the present invention, the oxidizing agent may be air or a diluent gas doped with an inert component.

According to the embodiment of the invention, a temperature sensing device for judging whether the fuel gas to be tested is spontaneously combusted is arranged in the testing cavity 1.

Illustratively, the fuel gas to be tested and the oxidant are sprayed into the testing cavity 1, and if the temperature detected by the temperature sensing device is in a stable state within y seconds, it indicates that the fuel gas to be tested does not reach the spontaneous combustion temperature and burns. Specifically, if the temperature change detected by the temperature sensing device is within 5-10 seconds, the temperature sensing device can be determined to be in a stable state, namely, the to-be-detected gas does not spontaneously combust.

The fuel gas to be tested and the oxidant are sprayed into the testing cavity 1, if the temperature sensing device detects that the temperature rises suddenly above a second temperature value, specifically, if the temperature detected by the temperature sensing device rises within 5-10 seconds and exceeds 20 ℃, the fuel gas to be tested can be determined to be spontaneously combusted.

According to an embodiment of the present invention, the temperature sensing device may include a thermocouple 12 or a temperature sensor or other temperature monitoring device.

According to the embodiment of the invention, the cavity heating device is used for heating the test cavity 1, the cavity heating device heats the interior of the test cavity 1 to the target preset temperature, and the adaptive adjustment is carried out according to the temperature condition monitored by the temperature sensing device, so that the temperature in the test cavity 1 is not lower than the target preset temperature.

According to the embodiment of the invention, the chamber heating device can be a heating furnace arranged outside the test chamber 1, and the inner wall of the heating furnace body 6 of the heating furnace is close to or abutted against the outer wall of the test chamber 1. The chamber heating device may also be a heating tube or a heating ring disposed inside the testing chamber 1.

According to the embodiment of the present invention, a preheating device 4 is provided between the oxidant source 3 and the showerhead 16. Preheating device 4 is used for preheating the oxidant that treats to spout into test cavity 1, and through preheating the oxidant to the target temperature of predetermineeing, and then reduce the influence that the difference in temperature of oxidant and test cavity 1 inside caused the test result.

According to the embodiment of the present invention, the preheating device 4 includes a heating chamber, a heating device and a temperature sensing device, which may be embodied as a set or spiral of heating wires and temperature sensors disposed in the heating chamber. And the oxidant part enters the heating cavity, and is heated to a target preset temperature under the cooperation of the heating device and the temperature sensing device.

According to the embodiment of the invention, the oxidant source 3, the fuel gas source 2 to be tested, the preheating device 4 and the spray head 16 are connected through pipelines, and particularly, the oxidant source, the fuel gas source, the preheating device and the spray head can be communicated and connected through a high-pressure hose.

The invention also discloses a flameless combustion spontaneous combustion temperature testing system which comprises the flameless combustion spontaneous combustion temperature testing device.

Specifically, the system comprises a central control unit.

The gas flowmeter comprises a first electromagnetic valve 8 and a first flowmeter 9 which are arranged between a gas source 2 to be tested and a testing cavity 1.

And a second solenoid valve 10 and a second flow meter 11 disposed between the oxidant source 3 and the test chamber 1.

The first electromagnetic valve 8, the second electromagnetic valve 10, the first flow meter 9, the second flow meter 11 and the temperature sensing device are all connected with the central control unit.

According to the embodiment of the invention, the central control unit is a device for centrally managing and controlling the temperature sensing device, the cavity heating device, the preheating device 4, the first electromagnetic valve 8, the second electromagnetic valve 10, the first flowmeter 9 and the second flowmeter 11.

According to the embodiment of the present invention, the central control unit may be specifically a PLC controller or a computer 5 or other electronic devices.

In a preferred scheme, the computer 5 is adopted to cooperate with a corresponding software program to perform control, operation, recording and analysis. The software program is prior art and is not further described again.

According to the embodiment of the invention, the gas source 2 to be measured can be a high-pressure steel cylinder or a combination of multiple high-pressure steel cylinders, and is used for providing the gas to be measured of single-component gas or multi-component gas mixture.

According to embodiments of the present invention, the oxidant source 3 may be an oxygen cylinder or air compressed using an air compressor or both or in combination with other compressed gases.

According to the embodiment of the invention, the central control unit adjusts the first electromagnetic valve 8 and the second electromagnetic valve 10 through the data fed back by the first flowmeter 9 and the second flowmeter 11, controls the flow and the proportion of the fuel gas to be tested and the oxidant sprayed into the testing cavity 1, and avoids the fuel gas to be tested from being diffused and combusted.

The invention also discloses a method for testing the flameless combustion spontaneous combustion temperature by using the flameless combustion spontaneous combustion temperature testing device, which is shown in a flow chart of the flameless combustion spontaneous combustion temperature testing method shown in figure 3 and specifically comprises the following steps.

S1, heating the internal temperature of the testing cavity 1 to a target preset temperature through the cavity heating device, and heating the temperature of the oxidant to be sprayed into the testing cavity 1 to the target preset temperature through the preheating device 4.

According to the embodiment of the invention, the central control unit controls the cavity heating device to heat the testing cavity 1, the heating is stopped or the heating power of the cavity heating device is reduced after the temperature in the testing cavity 1 fed back by the temperature sensing device in the cavity 1 to be tested reaches the target preset temperature, and the temperature in the testing cavity 1 is kept not lower than the target preset temperature.

According to an embodiment of the present invention, the central control unit controls the preheating device 4 to heat the temperature of the oxidant to be injected into the test chamber 1 to the target preset temperature.

S2, spraying the heated oxidant into the testing cavity 1 in a jet mode, and executing S3 after the cavity 1 to be tested is filled with the oxidant.

According to the embodiment of the invention, the central control unit controls to open the first solenoid valve 8 and the second solenoid valve 10, so that the fuel gas to be tested and the oxidant are injected into the test cavity 1 through the nozzle 16 in a jet manner.

According to the embodiment of the invention, the central control unit adjusts the first electromagnetic valve 8 and the second electromagnetic valve 10 according to the data fed back by the first flow meter 9 and the second flow meter 11, and controls the flow rate and the proportion of the gas to be tested and the oxidant which are sprayed into the test cavity 1, so as to control the gas to be tested to generate flameless combustion.

And S3, spraying the fuel gas to be tested into the testing cavity 1, recording the temperature change of the temperature sensing device, judging whether the fuel gas to be tested spontaneously ignites or not according to the temperature change condition, and selectively entering the next operation, wherein the specific performance is as substeps S31 and S32.

S31, if the internal temperature of the testing cavity 1 is in a stable state within y seconds, the fact that the fuel gas to be tested does not reach the spontaneous combustion temperature and burns is indicated, the fuel gas to be tested is firstly stopped being sprayed, then the oxidant is stopped being sprayed, then the step S1 is returned, and the first temperature value is increased on the basis that the internal temperature of the testing cavity 1 and the heating temperature of the oxidant are the target preset temperature.

According to an embodiment of the present invention, the steady state means that the temperature sensing device detects a temperature change within 5 ℃.

According to the embodiment of the invention, the value range of y is 5-10, that is, within 5-10 seconds, if the temperature change of the temperature sensing device is less than 5 ℃, it can be determined that the gas to be detected does not spontaneously combust, and the target preset temperature is lower than the spontaneous combustion temperature of flameless combustion of the gas to be detected.

According to the embodiment of the invention, the target preset temperature is the estimated temperature of the flameless combustion spontaneous combustion temperature of the gas to be measured according to the existing data.

According to an embodiment of the present invention, the first temperature value is a gradient temperature, and specifically, the first temperature value is 5 ℃.

S32, if the internal temperature of the testing cavity 1 rises suddenly above the second temperature value, it is indicated that the fuel gas to be tested is burnt, after the burning time lasts at least x seconds, the fuel gas to be tested and the oxidant are stopped to be sprayed simultaneously, or the fuel gas to be tested is stopped to be sprayed firstly, then the oxidant is stopped to be sprayed, the testing cavity is waited to be cooled, S1 is returned, and the internal temperature of the testing cavity 1 and the heating temperature of the oxidant are reduced to a third temperature value on the basis of the target preset temperature.

According to the embodiment of the invention, the second temperature value is 20 ℃, namely the monitored temperature of the temperature sensor suddenly rises by 20 ℃, the sudden rise is determined according to the size of the internal space of the testing cavity 1, and specifically, the temperature rise monitored by the temperature sensor exceeds 20 ℃ within 3-5 seconds, so that the spontaneous combustion of the gas to be tested can be determined.

According to an embodiment of the present invention, the third temperature value is a gradient temperature, and specifically, the third temperature value is 1 ℃.

And S4, repeatedly executing S1, S2 and S3 until the fuel gas to be tested is combusted when the internal temperature of the test cavity 1 and the temperature of the oxidant are heated to (a third temperature value which is n times of the target preset temperature plus the first temperature value which is m times) and the temperature of the oxidant), and the fuel gas to be tested is not combusted when the internal temperature of the test cavity 1 and the temperature of the oxidant are heated to (a third temperature value which is n +1 times of the target preset temperature plus the first temperature value which is m times) and the temperature of the oxidant, and recording (the third temperature value which is n times of the target preset temperature plus the first temperature value which is m times) and the temperature of the fuel gas to be tested) as the spontaneous combustion temperature of the fuel.

Wherein m and n are natural numbers, and the first temperature value is larger than the third temperature value.

According to the embodiment of the present invention, if the result of the first execution of S3 in the test process indicates spontaneous combustion of the fuel gas to be tested, the third temperature value may be set to 5 ℃. That is, during operation, the auto-ignition temperature may be precisely measured by first roughly determining an approximate range of auto-ignition temperatures, and then adjusting the target preset temperature multiple times.

According to the embodiment of the invention, the fuel gas to be measured comprises single fuel gas or mixed fuel gas, and the oxidant comprises air or diluent gas with inert components mixed in the oxygen.

In order to facilitate the understanding of the technical solutions of the present invention, the following description will be further described with a specific embodiment.