System and method for testing flameless combustion spontaneous combustion temperature of combustible gas in high-pressure environment
阅读说明：本技术 高压环境中可燃气无焰燃烧自燃温度测试系统及方法 (System and method for testing flameless combustion spontaneous combustion temperature of combustible gas in high-pressure environment ) 是由 颜蓓蓓 苏红 周生权 陈冠益 程占军 朱小超 于 2020-07-10 设计创作，主要内容包括：本发明公开了一种高压环境中可燃气无焰燃烧自燃温度测试系统,用于测量预设压强范围下的待测燃气无焰燃烧的自燃温度,包括测试腔体、安全联锁单元、控制单元、温控加热单元和中控单元。测试腔体用于提供待测燃气无焰燃烧的场所,测试腔体设置有进气通道,进气通道上设置有喷头,喷头分别与待测燃气源和氧化剂源连接,测试腔体内设置有温度传感器和气压传感器；安全联锁单元,设置在测试腔体上,用于调节控制测试腔体内的气压；温控加热单元,用于对测试腔体进行加热；控制单元,用于控制待测燃气和氧化剂通过喷头喷入测试腔体内；中控单元与安全联锁单元、控制单元和温控加热单元连接,可以精准地测量预设压强范围下待测燃气无焰燃烧的自燃温度。(The invention discloses a combustible gas flameless combustion spontaneous combustion temperature test system in a high-pressure environment, which is used for measuring the spontaneous combustion temperature of the combustible gas flameless combustion to be tested within a preset pressure range and comprises a test cavity, a safety interlocking unit, a control unit, a temperature control heating unit and a central control unit. The test cavity is used for providing a flameless combustion place for the gas to be tested, the test cavity is provided with an air inlet channel, the air inlet channel is provided with a spray head, the spray head is respectively connected with a gas source to be tested and an oxidant source, and a temperature sensor and a gas pressure sensor are arranged in the test cavity; the safety interlocking unit is arranged on the test cavity and used for adjusting and controlling the air pressure in the test cavity; the temperature control heating unit is used for heating the test cavity; the control unit is used for controlling the fuel gas and the oxidant to be tested to be sprayed into the test cavity through the spray head; the central control unit is connected with the safety interlocking unit, the control unit and the temperature control heating unit, and can accurately measure the spontaneous combustion temperature of flameless combustion of the gas to be measured within a preset pressure range.)
1. The utility model provides a combustible gas flameless combustion spontaneous combustion temperature test system in high pressure environment for measure the spontaneous combustion temperature of the gas flameless combustion that awaits measuring under the preset pressure intensity scope, wherein, preset pressure intensity scope is greater than standard atmospheric pressure, its characterized in that includes:
the test cavity is used for providing a flameless combustion place for gas to be tested and comprises an air inlet channel, a spray head for spraying the gas to be tested and an oxidant is arranged on the air inlet channel, the spray head is respectively connected with a gas source to be tested and an oxidant source, a temperature sensor and an air pressure sensor are arranged in the test cavity, the temperature sensor is used for judging whether the gas to be tested spontaneously combusts or not, and the air pressure sensor is used for detecting air pressure in the test cavity;
the safety interlocking unit is arranged on the test cavity and used for adjusting and controlling the air pressure in the test cavity;
the temperature control heating unit is used for heating the test cavity;
the control unit is arranged among the spray head, the fuel gas source to be tested and the oxidant source and is used for controlling the fuel gas to be tested and the oxidant to be sprayed into the test cavity through the spray head;
the central control unit is connected with the temperature sensor and used for receiving and judging the temperature signal transmitted by the temperature sensor and transmitting the judgment result of the temperature signal to the temperature control heating unit, and the central control unit is connected with the air pressure sensor and used for receiving and judging the air pressure signal transmitted by the air pressure sensor and transmitting the judgment result of the air pressure signal to the safety interlocking unit.
2. The system for testing the flameless combustion spontaneous combustion temperature of combustible gas in the high-pressure environment according to claim 1, further comprising a vacuum pump, wherein the vacuum pump is connected to the test chamber and used for pumping out gas in the test chamber to adjust the gas pressure in the test chamber, a third electromagnetic valve is arranged between the vacuum pump and the test chamber, the control unit is connected to the vacuum pump and the third electromagnetic valve, and the control unit sends a control signal to the vacuum pump and the third electromagnetic valve.
3. The system for testing the flameless combustion spontaneous combustion temperature of combustible gas in a high-pressure environment according to claim 1 or 2, wherein the safety interlocking unit comprises a pressure relief port and an automatic pressure regulating valve, and the automatic pressure regulating valve is arranged between the pressure relief port and the test cavity and used for regulating the air pressure in the test cavity.
4. The system for testing the flameless combustion spontaneous combustion temperature of combustible gas in a high-pressure environment according to claim 3, wherein the safety interlock unit further comprises a safety valve disposed between the pressure relief port and the test chamber, the safety valve is connected in parallel with the automatic regulating valve, and the safety valve communicates with the interior of the test chamber to assist the automatic regulating valve in pressure relief after the air pressure in the test chamber exceeds a preset first safety air pressure.
5. The system for testing the flameless combustion spontaneous combustion temperature of combustible gas in a high-pressure environment according to claim 4, wherein the safety interlock unit further comprises a rupture disk disposed between the pressure relief opening and the test chamber, the rupture disk is connected in parallel with the automatic regulating valve and the safety valve, the rupture disk ruptures after the pressure in the test chamber exceeds a second preset safety pressure, so that the pressure relief opening is communicated with the inside of the test chamber for rapid pressure relief, and the first safety pressure is smaller than the second safety pressure.
6. The system for testing the flameless combustion spontaneous combustion temperature of combustible gas in the high-pressure environment according to claim 1 or 2, wherein the temperature-controlled heating unit comprises a heating sleeve arranged outside the test cavity, and the heating sleeve is connected with the central control unit.
7. The system for testing the flameless combustion auto-ignition temperature of a combustible gas in a high-pressure environment according to claim 6, wherein the temperature-controlled heating unit further comprises: and the preheating device is arranged between the oxidant source and the spray head and is used for preheating the oxidant to be sprayed into the test cavity.
8. The system for testing the flameless combustion autoignition temperature of the combustible gas in the high-pressure environment according to claim 1 or 2, wherein the control unit comprises a first solenoid valve and a first flow meter which are arranged between the nozzle and the fuel gas source to be tested, and a second solenoid valve and a second flow meter which are arranged between the nozzle and the oxidant source, the first flow meter and the second flow meter are connected with the central control unit and send monitored flow signals to the central control unit, and the first solenoid valve and the second solenoid valve are connected with the central control unit and receive control signals sent by the central control unit.
9. A method for testing the flameless combustion auto-ignition temperature of a combustible gas using the flameless combustion auto-ignition temperature test system for a combustible gas in a high-pressure environment according to any one of claims 1 to 8, comprising:
s1, raising the internal temperature of the test cavity to a target preset temperature through the heating sleeve, and raising the temperature of the oxidant to be introduced to the target preheating temperature through the preheating device;
s2, spraying the heated oxidant into the test cavity through a spray head, controlling the gas pressure in the test cavity to be a preset pressure through an automatic regulating valve, and spraying the fuel gas to be tested into the test cavity through the spray head;
s3, recording the temperature change of the temperature sensor in the test cavity and judging:
s31, if the internal temperature of the testing cavity is in a stable state within y seconds, indicating that the fuel gas to be tested does not reach the spontaneous combustion temperature and burns, stopping injecting the fuel gas to be tested, stopping injecting the oxidant, returning to S1, and increasing the internal temperature of the testing cavity and the heating temperature of the oxidant by 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 to be tested and the oxidant 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 cooled, the operation returns to S1, and the internal temperature of the testing cavity and the heating temperature of the oxidant are both 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 gas to be tested is burned when the temperature inside the test chamber and the temperature of the oxidant are heated to (a target preheating temperature + a first temperature value m times-a second temperature value n times) deg.c, and the gas to be tested is not burned when the temperature inside the test chamber and the temperature of the oxidant are heated to (a target preheating temperature + a first temperature value m times- (a second temperature value n +1) times) deg.c, and recording (a target preheating temperature + a first temperature value m times-a second temperature value n times) deg.c as the autoignition temperature of the gas to be tested without flame at a preset pressure;
wherein m and n are natural numbers, and the first temperature value is larger than the third temperature value.
10. The testing method as claimed in claim 9, wherein in S1, before raising the temperature inside the testing chamber to a target preset temperature by using the heating sleeve and raising the temperature of the oxidant to be introduced to the target preheating temperature by the preheating device, the method further comprises the step of evacuating the gas inside the testing chamber by using a vacuum pump.
Technical Field
The invention relates to the technical field of gas ignition point detection, in particular to a system and a method for testing the flameless combustion spontaneous combustion temperature of combustible gas in a high-pressure environment.
Background
The spontaneous combustion temperature of combustible gas is one of important indexes for judging and evaluating the fire risk of combustible gas substances, and the lower the spontaneous combustion temperature is, the higher the risk of spontaneous combustion fire of the combustible gas is. The spontaneous combustion temperature is also called ignition temperature, and is the lowest temperature at which the substance can be combusted due to the rise of temperature when the rate of heat release of the substance due to exothermic oxidation reaction is higher than the rate of heat release under specific conditions and without the action of an open flame source such as flame or electric spark. The auto-ignition temperature of the gas is strongly related to the mode of combustion, ambient pressure, flow rate, oxygen content and vessel size.
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 point of fuel.
In the hot spontaneous combustion theory and the research of some technicians in the field and the like, the pressure has obvious influence on the spontaneous combustion temperature, and a technician in the field invents a device and a method for testing the spontaneous combustion temperature of gas or liquid in a high-pressure oxygen-enriched environment, so that the problems that in the process of testing combustible gas, the combustible gas is oxidized completely when reaching the spontaneous combustion point, the temperature and the pressure do not change suddenly, and the spontaneous combustion point cannot be tested due to slow oxidation reaction between the combustible gas and oxygen in the air are solved; one skilled in the art has invented a device for testing the spontaneous ignition point in a high-pressure oxygen-enriched environment, which can measure and record the pressure and temperature information in the device in real time and analyze the spontaneous ignition temperature of the material to be tested under different oxygen-enriched concentrations and pressures.
At present, the test of the flameless combustion spontaneous combustion temperature is usually carried out in the atmosphere of normal pressure, and the spontaneous combustion temperature measurement under different pressure conditions cannot be completed, so that an experimental device for testing the spontaneous combustion temperature in the flameless combustion of combustible gas in a high-pressure environment is needed, a certain reference basis is provided for the application of various combustible gases in the flameless combustion high-pressure environment, the application of combustible gas in the high-pressure field of flameless combustion is promoted, more importantly, the chemical explosion accident of a combustor can be prevented, and the safe operation of the combustor is ensured.
Disclosure of Invention
Technical problem to be solved
In view of the fact that no suitable testing device is available at present for accurately and conveniently testing the spontaneous combustion temperature of the combustible gas in the flameless combustion in the high-pressure environment, the invention provides a system and a method for testing the spontaneous combustion temperature of the combustible gas in the flameless combustion in the high-pressure environment, and the spontaneous combustion temperature of the combustible gas in the flameless combustion can be conveniently and accurately tested in the preset pressure environment.
(II) technical scheme
The invention provides a combustible gas flameless combustion spontaneous combustion temperature testing system in a high-pressure environment.
According to an embodiment of the invention, the system for testing the flameless combustion autoignition temperature of the combustible gas in the high-pressure environment comprises:
the test cavity is used for providing a flameless combustion place for gas to be tested and comprises an air inlet channel, a spray head for spraying the gas to be tested and an oxidant is arranged on the air inlet channel, the spray head is respectively connected with a gas source to be tested and an oxidant source, a temperature sensor and an air pressure sensor are arranged in the test cavity, the temperature sensor is used for judging whether the gas to be tested spontaneously combusts or not, and the air pressure sensor is used for detecting air pressure in the test cavity;
the safety interlocking unit is arranged on the test cavity and used for adjusting and controlling the air pressure in the test cavity;
the temperature control heating unit is used for heating the test cavity;
the control unit is arranged among the spray head, the fuel gas source to be tested and the oxidant source and is used for controlling the fuel gas to be tested and the oxidant to be sprayed into the test cavity through the spray head;
the central control unit is connected with the temperature sensor and used for receiving and judging the temperature signal transmitted by the temperature sensor and transmitting the judgment result of the temperature signal to the temperature control heating unit, and the central control unit is connected with the air pressure sensor and used for receiving and judging the air pressure signal transmitted by the air pressure sensor and transmitting the judgment result of the air pressure signal to the safety interlocking unit.
According to the embodiment of the invention, the testing device further comprises a vacuum pump, the vacuum pump is connected with the testing cavity and used for pumping out gas in the testing cavity to adjust the air pressure in the testing cavity, a third electromagnetic valve is arranged between the vacuum pump and the testing cavity, the control unit is connected with the vacuum pump and the third electromagnetic valve, and the control unit sends control signals to the vacuum pump and the third electromagnetic valve.
According to an embodiment of the invention, the safety interlock unit comprises a pressure relief port and an automatic pressure regulating valve, the automatic pressure regulating valve is arranged between the pressure relief port and the test cavity and is used for regulating the air pressure in the test cavity.
According to the embodiment of the invention, the safety interlocking unit further comprises a safety valve arranged between the pressure relief port and the test cavity, the safety valve is connected with the automatic regulating valve in parallel, and the safety valve is communicated with the interior of the test cavity to assist the automatic regulating valve in pressure relief after the air pressure in the test cavity exceeds a preset first safety air pressure.
According to the embodiment of the invention, the safety interlocking unit further comprises a rupture disc arranged between the pressure relief port and the test cavity, the rupture disc is connected with the automatic regulating valve and the safety valve in parallel, the rupture disc is exploded after the air pressure in the test cavity exceeds a preset second safety air pressure, so that the pressure relief port is communicated with the interior of the test cavity to be quickly relieved, and the first safety air pressure is smaller than the second safety air pressure.
According to the embodiment of the invention, the temperature control heating unit comprises a heating sleeve arranged outside the test cavity, and the heating sleeve is connected with the central control unit.
According to an embodiment of the invention, the temperature controlled heating unit further comprises: and the preheating device is arranged between the oxidant source and the spray head and is used for preheating the oxidant to be sprayed into the test cavity.
According to an embodiment of the invention, the control unit comprises a first electromagnetic valve and a first flow meter which are arranged between the spray head and the gas source to be tested, and a second electromagnetic valve and a second flow meter which are arranged between the spray head and the oxidant source, the first flow meter and the second flow meter are connected with the central control unit and send monitored flow signals to the central control unit, and the first electromagnetic valve and the second electromagnetic valve are connected with the central control unit and receive control signals sent by the central control unit.
The invention also discloses a method for testing the flameless combustion spontaneous combustion temperature of combustible gas by using the flameless combustion spontaneous combustion temperature test system of combustible gas in the high-pressure environment, which comprises the following steps:
s1, raising the internal temperature of the test cavity to a target preset temperature through the heating sleeve, and raising the temperature of the oxidant to be introduced to the target preheating temperature through the preheating device;
s2, spraying the heated oxidant into the test cavity through a spray head, controlling the gas pressure in the test cavity to be a preset pressure through an automatic regulating valve, and spraying the fuel gas to be tested into the test cavity through the spray head;
s3, recording the temperature change of the temperature sensor in the test cavity and judging:
s31, if the internal temperature of the testing cavity is in a stable state within y seconds, indicating that the fuel gas to be tested does not reach the spontaneous combustion temperature and burns, stopping injecting the fuel gas to be tested, stopping injecting the oxidant, returning to S1, and increasing the internal temperature of the testing cavity and the heating temperature of the oxidant by a first temperature value on the basis of the target preset temperature;
s32, if the internal temperature of the test cavity rises suddenly above a 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 simultaneously stopped being sprayed in or firstly the fuel gas to be tested is stopped being sprayed in, then the oxidant is stopped being sprayed in, the test cavity is waited to be cooled, the operation returns to S1, and the internal temperature of the test cavity and the heating temperature of the oxidant are both at the base of the target preset temperature
Reducing the third temperature value on the basis;
s4, repeatedly executing the substeps S31 and S32 of S1, S2, S3 and S3 until the gas to be tested is burned when the temperature inside the test chamber and the temperature of the oxidant are heated to (a target preheating temperature + a first temperature value m times-a second temperature value n times) deg.c, and the gas to be tested is not burned when the temperature inside the test chamber and the temperature of the oxidant are heated to (a target preheating temperature + a first temperature value m times- (a second temperature value n +1) times) deg.c, and recording (a target preheating temperature + a first temperature value m times-a second temperature value n times) deg.c as the autoignition temperature of the gas to be tested without flame at a preset pressure;
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, in S1, before raising the temperature inside the test chamber to the target preset temperature by using the heating sleeve and raising the temperature of the oxidant to be introduced to the target preheating temperature by the preheating device, the method further includes: and pumping out gas in the test cavity by using a vacuum pump.
(III) advantageous effects
According to the invention, the pressure of gas in the test cavity is regulated and controlled through the automatic pressure regulating valve, the gas pressure in the test cavity is matched with the temperature sensor and the gas pressure sensor in the test cavity, the temperature control heating unit, the control unit and the central control unit, so that the gas pressure and the temperature in the test cavity can be accurately controlled, and the spontaneous ignition point of flameless combustion of the gas to be tested can be accurately obtained through multiple tests. Moreover, the safety of the device can be greatly improved by matching the automatic pressure regulating valve with the safety valve and the rupture disk.
Drawings
FIG. 1 is a schematic diagram illustrating a connection relationship of a flameless combustion auto-ignition temperature test system for combustible gas in a high-pressure environment according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a nozzle of a flameless combustion auto-ignition temperature testing system for combustible gas in a high-pressure environment according to an embodiment of the present invention;
FIG. 3 is a flow chart of a method for testing a flameless combustion auto-ignition temperature test system for combustible gas in a high-pressure environment according to an embodiment of the present invention;
wherein, 1 represents 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 jacket; 7 denotes a thermal insulation cover; 8 denotes a first solenoid valve; 9 denotes a first flow meter; 10 denotes a second flow meter; 11 denotes a second electromagnetic valve; 12 denotes a temperature sensor; 13 denotes an air pressure sensor; 14 denotes a vacuum pump; 15 denotes a third electromagnetic valve; 16 denotes an automatic pressure regulating valve; 17 denotes a rupture disk; 18 denotes a safety valve; 19 denotes a pressure relief port; 20 denotes an oxidant jet; 21 denotes a gas nozzle to be measured; 22 denotes an intake passage; and 23 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 slight variations depending on the experimental location, specifically where the local equipment or vessel is not subject to atmospheric pressure, and whose internal pressure is one atmosphere, calculated as 0.1 MPa. Generally, 0.1 to 1.6MPa is low pressure, 1.6 to 10MPa is medium pressure, 10 to 100MPa is high pressure, and >100MPa is ultrahigh pressure.
FIG. 1 is a schematic diagram illustrating a connection relationship of a flameless combustion auto-ignition temperature test system for combustible gas in a high-pressure environment according to an embodiment of the present invention.
As shown in FIG. 1, the system for testing the flameless combustion spontaneous combustion temperature of combustible gas in a high-pressure environment comprises a testing cavity 1, a safety interlocking unit, a control unit, a temperature control heating unit and a central control unit.
According to the embodiment of the invention, the test chamber 1 is used for providing a flameless combustion place for the fuel gas to be tested, and the test chamber 1 can be a square, spherical or ellipsoidal sealed chamber.
According to the embodiment of the present invention, preferably, the test chamber 1 is a cube. The outside of cube sets up control by temperature change heating element, and the control by temperature change heating element outside sets up insulation cover 7.
According to the embodiment of the invention, the testing chamber 1 comprises an air inlet channel 22, and a nozzle 23 for injecting fuel gas to be tested and oxidant is arranged on the air inlet channel 22.
According to the embodiment of the invention, as shown in fig. 2, the nozzle 23 is provided with a
According to the embodiment of the invention, the nozzle 23 is respectively connected with the gas source 2 to be detected and the oxidant source 3, the oxidant source 3 can be an oxygen cylinder or an air compressor for compressing air or the combination of the two or other compressed gases, and the gas source 2 to be detected can be a high-pressure steel cylinder or a combination of multiple groups of high-pressure steel cylinders for providing the gas to be detected of single-component gas or multi-component mixed gas.
According to the embodiment of the invention, the temperature sensor 12 is arranged in the test cavity 1, the temperature sensor 12 is used for judging whether the gas to be tested is spontaneously combusted, and specifically, if the temperature sensor 12 monitors that the temperature in the test cavity 1 suddenly rises. For example, the temperature rises to more than 20 ℃ within 3-10 seconds, and the spontaneous combustion of the fuel gas to be measured can be judged. And if the temperature sensor monitors that the fluctuation range of the temperature does not exceed 1 ℃ within 10 seconds, the situation that the fuel gas to be detected is not spontaneously combusted can be judged. The specific judgment temperature can be adjusted according to the test process and the precision.
According to the embodiment of the invention, the air pressure sensor 13 is arranged in the test cavity 1, and the air pressure sensor 13 is used for detecting the air pressure in the test cavity 1.
According to the embodiment of the invention, the safety interlocking unit is arranged on the testing cavity 1 and used for adjusting and controlling the air pressure in the testing cavity 1, the internal space of the testing cavity 1 is ensured to be closed before the air pressure in the testing cavity 1 reaches a set value, and the internal space and the external space of the testing cavity 1 are communicated after the air pressure in the cavity 1 to be tested reaches the set value to perform pressure relief control, so that the air pressure in the testing cavity 1 is kept constant near the set value.
According to an embodiment of the present invention, the temperature-controlled heating unit is used for heating the test chamber 1. Specifically, including setting up the heating sleeve 6 in the test cavity 1 outside, further, the heating sleeve 6 outside is provided with insulation cover 7, prevents that the heat energy of heating sleeve 6 from radiating to the surrounding space, increases the heating efficiency of heating sleeve 6 to test cavity 1.
According to the embodiment of the invention, the control unit is arranged between the spray head 23 and the gas source 2 and the oxidant source 3 to be tested and is used for controlling the gas and the oxidant to be tested to be sprayed into the test cavity 1 through the spray head 23.
According to the embodiment of the invention, the central control unit is connected with the temperature sensor 12 and used for receiving and judging the temperature signal sent by the temperature sensor 12 and sending the judgment result of the temperature signal to the temperature control heating unit, and the central control unit is connected with the air pressure sensor 13 and used for receiving and judging the air pressure signal sent by the air pressure sensor and sending the judgment result of the air pressure signal to the safety interlocking unit.
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 programs in the computer 5 are prior art and will not be described further.
According to the embodiment of the invention, the testing device further comprises a vacuum pump 14, the vacuum pump 14 is connected with the testing cavity 1 and used for pumping gas in the testing cavity 1 out to adjust the air pressure in the testing cavity 1, a third electromagnetic valve 15 is arranged between the vacuum pump 14 and the testing cavity 1, the control unit is connected with the vacuum pump 14 and the third electromagnetic valve 15, and the control unit sends control signals to the vacuum pump 14 and the third electromagnetic valve 15. Specifically, because the test chamber 1 is a closed space, after each test, gas higher than the standard atmospheric pressure exists in the test chamber, and the gas in the test chamber needs to be pumped out by the vacuum pump 14 to return to the normal pressure. In addition, in the testing process, the vacuum pump 14 can be used for pumping out the gas in the testing chamber 1 after the judging stage of the testing process, so as to prevent the influence on the subsequent steps.
According to an embodiment of the present invention, the safety interlock unit comprises a pressure relief port 19 and an automatic pressure regulating valve 16, the automatic pressure regulating valve 16 being disposed between the pressure relief port 19 and the test chamber 1 for regulating the pressure of the air pressure inside the test chamber 1. Specifically, after the automatic regulating valve 16 is set to a preset pressure, and after the pressure in the cavity to be tested 1 reaches a preset value, the automatic regulating valve 16 opens and communicates the testing cavity 1 with the external space to perform pressure relief control, and when the internal air pressure of the cavity to be tested 1 is lower than the preset value, the automatic regulating valve 16 closes the communication between the testing cavity 1 and the external space.
According to the embodiment of the invention, the safety interlocking unit further comprises a safety valve 18 arranged between the pressure relief opening 19 and the test cavity 1, the safety valve 18 is connected with the automatic regulating valve 16 in parallel, and the safety valve 18 is communicated with the auxiliary automatic regulating valve 16 inside the test cavity 1 for pressure relief after the air pressure in the test cavity 1 exceeds a preset first safety air pressure. Specifically, the first safe air pressure setting value is higher than the preset value of the automatic regulating valve 16, the air pressure in the testing cavity 1 cannot be effectively regulated by the automatic regulating valve 16 due to the fact that the rising speed of the air pressure in the testing cavity 1 is too high, and after the air pressure value in the testing cavity 1 rises to exceed the first safe air pressure, the safety valve 18 is opened to communicate the testing cavity 1 with the external space for auxiliary pressure relief.
According to the embodiment of the invention, the safety interlocking unit further comprises a rupture disk 17 arranged between the pressure relief port 19 and the test cavity 1, the rupture disk 17 is connected with the automatic regulating valve 16 and the safety valve 18 in parallel, the rupture disk 17 is exploded after the air pressure in the test cavity 1 exceeds a preset second safety air pressure, so that the pressure relief port 19 is communicated with the inside of the test cavity 1 for rapid pressure relief, and the first safety air pressure is smaller than the second safety air pressure. Specifically, the purpose of the rupture disk 17 is to prevent the air pressure in the test chamber 1 from suddenly rising in a short time to prevent the test chamber 1 from bursting.
According to the embodiment of the invention, the temperature control heating unit comprises a heating sleeve 7 arranged outside the test chamber 1, and the heating sleeve 7 is connected with the central control unit.
According to an embodiment of the present invention, the temperature-controlled heating unit further comprises a preheating device 4 disposed between the oxidant source 3 and the spray head 23, the preheating device 4 being configured to preheat the oxidant to be sprayed into the test chamber 1. Specifically, the preheating device 4 includes a heating chamber, a heating device and a temperature sensing device, and specifically, a set of or spiral heating wires and a temperature sensor are 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 control unit comprises a first electromagnetic valve 8 and a first flow meter 9 which are arranged between the spray head 23 and the gas source 2 to be tested, and a second electromagnetic valve 11 and a second flow meter 10 which are arranged between the spray head 23 and the oxidant source 3, wherein the first flow meter 9 and the second flow meter 10 are connected with the central control unit and send monitored flow signals to the central control unit, and the first electromagnetic valve 8 and the second electromagnetic valve 11 are connected with the central control unit and receive control signals sent by the central control unit. Specifically, the central control unit sends corresponding control signals to the first electromagnetic valve 8 and the second electromagnetic valve 11 according to the received flow signals, and the flow of the fuel gas to be detected and the flow of the oxidant are controlled.
The invention also discloses a testing method for testing the flameless combustion spontaneous combustion temperature of the combustible gas by using the flameless combustion spontaneous combustion temperature testing system of the combustible gas in the high-pressure environment, which comprises the following steps as shown in figure 3.
And S1, raising the internal temperature of the test cavity 1 to a target preset temperature through the heating sleeve 6, and raising the temperature of the oxidant to be introduced to the target preheating temperature through the preheating device 4.
According to the embodiment of the invention, the central control unit controls the heating sleeve 6 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 12 in the cavity 1 to be tested reaches the target preset temperature, the temperature in the testing cavity 1 is kept not lower than the target preset temperature, and similarly, the preheating device is used for heating the oxidant to be sprayed to the target preset temperature.
S2, spraying the heated oxidant into the test cavity 1 through the spray head 23, controlling the gas pressure in the test cavity 1 to be a preset pressure through the automatic regulating valve 16, and spraying the fuel gas to be tested into the test cavity 1 through the spray head 23.
According to the embodiment of the invention, the central control unit sends a control signal to open the second electromagnetic valve 11, so that the oxidant is sprayed into the testing cavity 1 through the spray head 23 in a jet manner, the air pressure sensor 13 monitors the air pressure in the testing cavity 1 and sends an air pressure signal to the central control unit, and after the air pressure in the cavity 1 to be tested reaches a preset value, the central control unit sends a control signal to open the first electromagnetic valve 8, so that the fuel gas to be tested is sprayed into the testing cavity 1 through the spray head 23 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 11 according to the data fed back by the first flow meter 9 and the second flow meter 10, 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, recording and judging the temperature change of the temperature sensor 12 in the testing cavity 1, judging whether the gas to be tested is subjected to spontaneous combustion according to the temperature change condition, and selecting to enter the next step of operation, wherein the specific expression is 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 both at the target preset temperature.
According to the embodiment of the present invention, the steady state means that the temperature sensor 13 detects a temperature change within 1 ℃.
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 1 ℃, it can be judged 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 self-ignition point 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 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 and the oxidant to be tested are simultaneously stopped spraying, or the fuel gas to be tested is firstly stopped spraying, then the oxidant is stopped spraying, the testing cavity is cooled, S1 is returned, and the internal temperature of the testing cavity and the heating temperature of the oxidant are both reduced by 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 ℃, that is, the temperature monitored by the temperature sensor 13 suddenly rises by 20 ℃, specifically, the temperature monitored by the temperature sensor rises by more than 20 ℃ within 5-10 seconds, and then the spontaneous combustion of the gas to be measured 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 ℃.
S4, repeating the substeps S31 and S32 of S1, S2, S3 and S3 until the gas to be tested is burnt when the temperature inside the test chamber and the temperature of the oxidant are heated to (the target preheating temperature + m times the first temperature value-n times the second temperature value) DEG C, and the gas to be tested is not burnt when the temperature inside the test chamber and the temperature of the oxidant are heated to (the target preheating temperature + m times the first temperature value- (n +1 times the second temperature value) DEG C, and recording (the target preheating temperature + m times the first temperature value-n times the second temperature value) DEG C as the spontaneous combustion temperature of the gas to be tested under the preset pressure without flame.
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
According to the embodiment of the present invention, in S1, before the heating sleeve 6 is used to raise the temperature inside the test chamber 1 to the target preset temperature and the preheating device 4 is used to raise the temperature of the oxidant to be introduced to the target preheating temperature, the method further includes the step of using the vacuum pump 14 to pump out the gas inside the test chamber 1, so as to prevent the residual gas from affecting the subsequent test.
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.
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