CN203053901U - System for simultaneously determining apparent thermo-physical property and spontaneous ignition temperature of combustible particles - Google Patents

Abstract

The utility model provides a system for simultaneously determining the apparent thermo-physical property and the spontaneous ignition temperature of combustible particles. The system is characterized in that a tubular physical property sample barrel (02) and a tubular spontaneous ignition sample barrel (15), which are siamesed, are placed on an electrical heating thin film (05), the upper openings and the lower openings of the tubular physical property sample barrel (02) and the tubular spontaneous ignition sample barrel (15) are sealed, a program-controlled power source (17) is connected with the electrical heating thin film (05), and a human-computer interface (19) is connected with the program-controlled power source (17) and a temperature collector (18) through serial communication interfaces. The system can be used for simultaneously measuring the thermal diffusion coefficient, heat conductivity, spontaneous ignition temperature and volume heating intensity of combustible particles of a same sample, so that possible sample deviation caused by the fact that multiple independent instruments are used for respectively measuring the thermo-physical property and the ignition property is avoided, and the spontaneous ignition temperature under test conditions is accurately tested. The system provided by the utility model has the advantages of small size, simple structure and low manufacturing cost and can be very conveniently manufactured into a miniaturized and intellectualized desktop or portable instrument.

Description

Measure the system of combustible granules apparent heat rerum natura and self-ignition temperature simultaneously

Technical field

The utility model relates to a kind of system that measures combustible granules apparent heat rerum natura and self-ignition temperature when the open-air self-ignition of coal pile in coal-burning power plant forecasts that is applicable to.

Background technology

In the colliery, the open-air dump of power plant etc., leave the dump in the carrying case in foreign-going ship and the railway transport course in, dieseling all usually takes place.High volatile raw coal spontaneous combustion phenomenon is commonplace, typical analytical data is bright, after volatile matter stores 6 months greater than 35% bottle coal and long-flame coal, its thermal loss average out to 4.9%, and after volatile matter stores 6 months less than 17% meager coal, its thermal loss average out to 2.0%, the spontaneous combustion of dump has not only caused enormous economic loss, also severe contamination around environment.In large coal-fired power plant, for guaranteeing ordinary production, must lay in tens0000 tons of coals to few hundred thousand tonnes of, the storage life is the several months, and spontaneous combustion of coal is that coal is stored maximum potential safety hazard.Because the source difference of power plant's coal, its physics, chemical property also have very big-difference, therefore need analyze its physics relevant with spontaneous combustion and chemical property, grasp the rule of its spontaneous combustion, in order to take to carry out forecast and the corresponding braking measure of spontaneous combustion trend.

Influence in the factor of self-ignition of coal pile, except the meteorological condition (as wind speed, wind direction, air themperature and humidity etc.) of environment of living in, the geometric properties (highly, the gradient, size-grade distribution and factor of porosity) piled up, the most important thing is thermophysical property and the low-temperature oxidation characteristic of coal.The spontaneous combustion process of dump can be described with the equivalent heat-conduction equation with internal heat resource

$\mathrm{\ρc}\frac{\∂T}{\∂\mathrm{\τ}}=\mathrm{\λ\ΔT}+Q_V\left(T\right)---\left(1\right)$

Wherein, ρ c is the equivalent volume thermal capacitance of piling up coal, and λ piles up the equivalent thermal conductivity (or claiming coefficient of heat conductivity) of coal, and Q _V(T) be the volume heat generation rate of piling up coal, it is relevant with the low-temperature oxidation characteristic of coal.Under the situation that the dump boundary condition is determined, ρ c, λ and Q _V(T) heat transmission and the chemical reaction process of dump inside have been determined jointly.When dump inside did not have low-temperature oxidation and low-temperature oxidation more weak, spontaneous combustion generally can not take place in the environment around heat can be passed by flank pass; And when low-temperature oxidation was strong, the energy of generation can't in time pass, and has caused the dump temperature progressively to raise, and oxidation reaction is violent further, and this self-excitation Effect finally causes the generation of self-ignition of coal pile.Therefore, grasp thermophysical property ρ c and λ and the volume heat generation rate Q of coal _V(T), the trend for the forecast self-ignition of coal pile is most important with the generation that suppresses self-ignition of coal pile.

The basic skills of the measurement of hot rerum natura all is that measured material is placed under the specific boundary condition, temperature or rate of temperature change on the heat flux that mensuration is passed through and the unique point (or face) calculate thermal conductivity λ, thermal diffusion coefficient a=λ/ρ c according to the solution of heat-conduction equation under this boundary condition again.For example, metastable state flat band method commonly used is according under the permanent hot-fluid heating condition, calculates thermal conductivity λ, thermal diffusion coefficient a=λ/ρ c in the metastable state stage by the temperature difference between mensuration hot face and the adiabatic face and the heat flow density of hot face.

Measure thermal diffusion coefficient a=λ/ρ c and will adopt the unstable state method.For example regular operating mode flat band method, metastable state flat band method, metastable state pipe method, thermal transient collimation method etc.The major advantage of unstable state method be test period short, device structure is simple etc.

Measure self-ignition temperature and adopt the temperature rise curve method usually.Sample is placed the air atmosphere of different temperatures one by one, measure the temperature variation curve of sample.If in heating process, temperature rise rate appears in the temperature variation curve by the phenomenon that accelerates slowly, and then spontaneous combustion has taken place in interpret sample; Otherwise, in heating process temperature rise rate do not occur marked change then interpret sample spontaneous combustion can not take place.The minimum test temperature that can make sample generation spontaneous combustion of Ce Lianging namely is self-ignition temperature thus.A kind of improved method is the air atmosphere that sample is placed slow intensification, so that sample and environment reach thermal equilibrium as far as possible, when sample reached certain temperature, when temperature rise rate surpassed the temperature rise rate of experimental enviroment, then this temperature namely was self-ignition temperature.

Measurement volumes heat generation rate Q _V(T) method also has a lot, for example adopts comprehensive thermal analyzer to measure apparent reaction activity and frequency factor, utilizes the Arrhenius formula to calculate apparent reaction rates, again according to the data indirect calculation volume heat generation rate of calorimetric; Sample can also be placed the air atmosphere of slow intensification, so that sample and environment reach thermal equilibrium as far as possible, according to heat-conduction equation, the volume heat generation rate Q of the temperature rise rate calculation sample when spontaneous combustion back 2 temperature take place equates _V(T).

Measuring system and the method for the hot rerum natura of existing measurement combustible granules and fire behaviour all are separate, and the instant heating rerum natura will be measured with different systems, diverse ways respectively with fire behaviour, is not easy to rig-site utilization.In addition, because different instrument to the requirement difference of sample, causes the measurement result on the different instruments can not be corresponding mutually, make the confidence level decline of data.

Still lack the system and method that to measure the hot rerum natura of combustible granules and fire behaviour simultaneously at present.

The utility model content

Technical problem to be solved in the utility model, just provide a kind of system that measures combustible granules apparent heat rerum natura and self-ignition temperature simultaneously, adopt the utility model, just can measure the hot rerum natura of combustible granules and fire behaviour simultaneously, and make things convenient for rig-site utilization, measurement result is the corresponding confidence level that improves data mutually.

Solve the problems of the technologies described above, the technical solution adopted in the utility model is:

A kind of system that measures combustible granules apparent heat rerum natura and self-ignition temperature simultaneously is characterized in that: comprising:

The rerum natura sample tube 02 of the tubulose made from highly heat-conductive material and spontaneous combustion sample tube 15 and the base plate that both are connected as one, base plate places with thermo electric material and makes on the electrical-heating film 05;

Adopt heat preservation plate material 06 to support below the electrical-heating film, two metal electrode 08 and 12 is drawn from back up pad 06 below;

The insulation lower cover made from the gas impermeable material of insulation at the end opening of rerum natura sample tube 02 09 seals, and is provided with physical property measurement sample S ₁ Central temperature sensor 04 is used for measuring the physical sample temperature T ₁The insulation lower cover made from the gas permeable material of insulation at the end opening of spontaneous combustion sample tube 15 11 seals, and is provided with spontaneous combustion specimen S ₂ Central temperature sensor 13 is used for measuring spontaneous combustion sample temperature T ₂

Tested physical property measurement sample S ₁03 and spontaneous combustion specimen S ₂14 are loaded into respectively in rerum natura sample tube 02 and the spontaneous combustion sample tube 15;

Insulation upper cover plate 01 sealing made from the gas impermeable material of insulation suitable for reading of rerum natura sample tube 02 is in insulation upper cover plate 16 sealings made from the gas permeable material of insulation suitable for reading of spontaneous combustion sample tube 15;

Base plate in the middle of two sample tubes is installed sample tube temperature sensor 10, is used for measuring sample tube temperature T _R

Two metal electrodes 08 of the programmable power supply 17 with serial communication interface and power measurement function and electrical-heating film 05 with 12 with link to each other, be used for control and metering heating power;

With physical property measurement sample S ₁ Central temperature sensor 04, spontaneous combustion specimen S ₂ Central temperature sensor 13 and sample tube temperature sensor 10 link to each other with the Temperature sampler 18 with serial communication function, are used for temperature data acquisition;

PC or man-machine interface (HMI) 19 and programmable power supply 17 and Temperature sampler 18 be by the serial communication interface (see figure 3) that links to each other, and is used for setup parameter, drives the heating power data that programmable power supply transmits from programmable power supply 17 respectively according in time linear rule heating, record, storage and the temperature data that transmits from Temperature sampler 18.

Adopt said system to measure the method for combustible granules apparent heat rerum natura and self-ignition temperature simultaneously, comprise the calorimetric calibration and test two steps:

The calorimetric calibration:

1.) at first do not loading measured object property testing sample S ₁03 and spontaneous combustion specimen S ₂Under 14 the situation, carry out the calorimetric reference test;

2.) turn on the power switch, give programmable power supply 17, Temperature sampler 18 and man-machine interface 19 power supplies, man-machine interface 19 set test temperature rise rate (representative value be 1-3 ℃/min); Start programmable power supply 17 heating, record sample tube temperature over time curve and heating power with variation of temperature curve P ₀(T), as the benchmark of heating power;

3.) close all power switches, allow instrument be cooled to environment temperature in order to the usefulness of test.

Test:

1.) with measured object property testing sample S ₁03 and spontaneous combustion specimen S ₂14 are loaded into respectively in rerum natura sample tube 02 and the spontaneous combustion sample tube 15;

2.) turn on the power switch, give programmable power supply 17, Temperature sampler 18 and man-machine interface 19 power supplies, man-machine interface 19 set test temperature rise rate (representative value be 1-3 ℃/min); Start programmable power supply 17 heating, record sample tube temperature T _R, physical property measurement sample temperature T _1cTemperature T with the spontaneous combustion specimen _2cAnd heating power is with variation of temperature curve P (T), at this moment

Be the heating power that adds every group of sample;

3.) after spontaneous combustion sample generation spontaneous combustion or the sample tube reached predetermined maximum temperature (for coal, representative value is 150 ℃), then control programmable power supply 17 and stop heating, preserve temperature and power data on the man-machine interface 19;

4.) record data are analyzed, when heating process reaches nominal situation, T _1R-T _1cRemain unchanged, this moment can basis

Calculate thermal diffusion coefficient a, according to

Calculate thermal capacity ρ c, according to the thermal conductivity λ of λ=ρ ca calculation sample; The temperature rise curve at two sample centers of contrast can be found out its burble point and corresponding temperature thereof, and this temperature namely is the self-ignition temperature of sample; Calculate the temperature rise rate of two samples when catching fire from two temperature rise curves

With Then can basis $Q_V\left(T\right)=\mathrm{\ρc}(\frac{{\∂T}_2}{\∂\mathrm{\τ}}-\frac{{\∂T}_1}{\∂\mathrm{\τ}})=\mathrm{\ρc}(\frac{{\∂T}_2}{\∂\mathrm{\τ}}-A)$ Calculate the volume heat generation rate Q of spontaneous combustion sample _V(T).

The utility model principle:

According to the right cylinder sample boundary temperature in time during linear change inner 2 temperature difference calculate thermal diffusion coefficient a=λ/ρ c; Temperature rise rate calculates thermal capacity ρ c with the heating power that adds to sample per sample, and then obtains thermal conductivity λ=ρ ca; Measurement has the separation (being the spontaneous combustion initial temperature) of two samples synchronization temperature rise curve on identical position under autoignition conditions and the no autoignition conditions; According to heat-conduction equation, the volume heat generation rate Q of the temperature rise rate calculation sample when spontaneous combustion back 2 temperature take place equates _V(T).

Technical solutions of the utility model: at elongate cylinder type sample S ₁The side form the boundary condition of isothermal, and will go up bottom surface and constitute adiabatic boundary condition with heat-barrier material, then in sample, can form the rotational symmetry temperature field of one dimension radial variations.If sample and air is isolated, when the temperature of sample side is pressed the linear rule rising in time, oxidation reaction can not take place then, this moment, the differential equation and the definite condition of this sample temperature field were

$\mathrm{\&rho;c}\frac{{\&PartialD;T}_1}{\&PartialD;\mathrm{\&tau;}}=\mathrm{\&lambda;}\frac{1}{r}\frac{\&PartialD;}{\&PartialD;r}\left(r\frac{{\&PartialD;T}_1}{\&PartialD;r}\right)0<r<R$

τ＝0,T ₁＝T ₀ (2)

$r=0,\frac{{\&PartialD;T}_1}{\&PartialD;r}=0$

r＝R,T ₁＝Aτ+T ₀

According to heat transfer theory, after heating beginning a period of time, the temperature in the sample all can raise with speed such as border temperature are linear, i.e. so-called nominal situation is shown in Fig. 1 (a).Its variation of temperature rule is

$T_1(r,\mathrm{\&tau;})-T_0=\frac{{\mathrm{AR}}^2}{a}[\frac{\mathrm{a\&tau;}}{R^2}-\frac{1}{2}(1-\frac{r^2}{R^2})]---\left(3\right)$

Wherein, a=ρ c/ λ.According to formula (3), the temperature at r=0 and r=R place is respectively

$T_{1c}-T_0=\frac{{\mathrm{AR}}^2}{a}(\frac{\mathrm{a\&tau;}}{R^2}-\frac{1}{2})---\left(4\right)$

With

$T_{1R}-T_0=\frac{{\mathrm{AR}}^2}{a}\left(\frac{\mathrm{a\&tau;}}{R^2}\right)---\left(5\right)$

This shows,

Therefore can calculate thermal diffusion coefficient according to above 2 temperature

$a=\frac{{\mathrm{AR}}^2}{2(T_{1R}-T_{1c})}$ (6)

In addition, according to energy equilibrium, under nominal situation, the temperature rise rate of each point is identical, if measure the heating power P that adds to sample _W, then $P_W=\mathrm{\&rho;cV}\frac{{\&PartialD;T}_1}{\&PartialD;\mathrm{\&tau;}}=\mathrm{\&rho;cVA},$ And then can draw respectively

$\mathrm{\&rho;c}=\frac{P_W}{\mathrm{VA}}---\left(7\right)$

With

λ＝ρca (8)

If will with above-mentioned same sample S ₂Communicate with air, when then the temperature in the sample side is elevated to certain temperature by linear rule in time, can begin to take place oxidation reaction, this moment, the differential equation and the definite condition of this sample temperature field were

$\mathrm{\&rho;c}\frac{{\&PartialD;T}_2}{\&PartialD;\mathrm{\&tau;}}=\mathrm{\&lambda;}\frac{1}{r}\frac{\&PartialD;}{\&PartialD;r}\left(r\frac{{\&PartialD;T}_2}{\&PartialD;r}\right)+Q_V\left(T\right)0<r<R$

τ＝0,T ₂＝T ₀ (9)

$r=0,\frac{{\&PartialD;T}_2}{\&PartialD;r}=0$

r＝R,T ₂＝Aτ+T ₀

If place two samples under the identical test condition and heating simultaneously, then before oxidation reaction began, temperature rise curve was be identical on both corresponding point, if sample S ₂In oxidation reaction has taken place, then its inner temperature rise curve will with sample S ₁Temperature rise curve separate, the temperature of this burble point is sample S ₂Self-ignition temperature T _i, shown in Fig. 1 (b).

Oxidation reaction will cause sample S during owing to catch fire ₂Temperature rise rate is than sample S ₁The temperature rise rate height, so near self-ignition temperature, the Temperature Distribution in two samples is consistent, but the temperature rise rate difference subtracts each other formula (9) and formula (2), obtains the volume heat generation rate of sample under the self-ignition temperature condition

$Q_V\left(T\right)=\mathrm{\&rho;c}(\frac{{\&PartialD;T}_2}{\&PartialD;\mathrm{\&tau;}}-\frac{{\&PartialD;T}_1}{\&PartialD;\mathrm{\&tau;}})=\mathrm{\&rho;c}(\frac{{\&PartialD;T}_2}{\&PartialD;\mathrm{\&tau;}}-A)---\left(10\right)$

According to the thermal physical property parameter that records, self-ignition temperature and volume calorific intensity, can also utilize mathematical model further the spontaneous combustion trend of stocking dump of power plant to be assessed.

The utility model just is based on above principle and measures the hot rerum natura of burnable granule material, self-ignition temperature and volume calorific intensity simultaneously.

Beneficial effect: according to the apparatus and method that the utility model proposes, can measure thermal diffusion coefficient, thermal conductivity, self-ignition temperature and the volume calorific intensity of burnable granule material to same sample simultaneously, the sample deviation that may cause when having avoided adopting many platform independent instrument to measure hot rerum natura and fire behaviour respectively.

According to the apparatus and method that the utility model proposes, can accurately record the self-ignition temperature under the test condition by spontaneous combustion relatively taking place and the temperature rise curve of the sample of spontaneous combustion not taking place.

Proving installation of the present utility model has volume advantage little, simple in structure and cheap for manufacturing cost, and the utmost point is convenient to make realization miniaturization, intelligentized Table top type or portable instrument.

Description of drawings

Fig. 1 is that the part in the system of the present utility model is formed the structure cross-sectional schematic;

Fig. 2 is the elevational schematic view of Fig. 1;

Fig. 3 is the schematic top plan view of Fig. 1;

Fig. 4 is that system of the present utility model forms and the annexation synoptic diagram;

Fig. 5 is one of method principle schematic of the present utility model;

Fig. 6 is two of method principle schematic of the present utility model.

Among the figure: insulation upper cover plate 01, ventilative insulation upper cover plate 16 by the rerum natura sample tube 02 that is connected and the spontaneous combustion sample tube 15 that highly heat-conductive material is made, is used for the sample S of thermophysical property measurement ₁03, for the sample S of self-ignition temperature and measurement of calorific value ₂14, insert sample S ₁The temperature sensor 04 at center inserts sample S ₂The temperature sensor 13 at center, electric heating film 05, base for supporting 06, base leg 07, electric heating piece extension line terminal 08 and 12, insulation lower cover 09, ventilative insulation lower cover 11, sample tube temperature sensor 10, programmable power supply 17 temperature acquisition instrument 19 and man-machine interface 19.

Embodiment

As shown in Figures 1 to 4, the system embodiment one of measuring combustible granules apparent heat rerum natura and self-ignition temperature simultaneously of the present invention comprises:

The base plate of making the rerum natura sample tube 02 of tubulose as shown in fig. 1 and spontaneous combustion sample tube 15 and both being connected as one with raffinal machining, base plate places with thermo electric material and makes on the electrical-heating film 05, because the thermal conductivity of aluminium is very high, can guarantee two sample tube temperature homogeneities and consistance.

Electrical-heating film 05 adopts the stainless steel etching to make, two metal electrode 08 and 12 adopts fine copper and heating plate 05 to rivet and draw from back up pad 06 below, the back up pad 06 that adopts heat preservation plate material to make below supports, back up pad 06 adopts the manufacturing of refractory plate, and base leg 07 can adopt the rubber manufacturing.

The insulation lower cover made from the gas impermeable material of insulation at the end opening of rerum natura sample tube 02 09 seals, and is provided with physical property measurement sample S ₁ Central temperature sensor 04 is used for measuring the physical sample temperature T ₁

The insulation lower cover made from the gas permeable material of insulation at the end opening of spontaneous combustion sample tube 15 11 seals, and is provided with spontaneous combustion specimen S ₂ Central temperature sensor 13 is used for measuring spontaneous combustion sample temperature T ₂

Tested physical property measurement sample S ₁03 and spontaneous combustion specimen S ₂14 are loaded into respectively in rerum natura sample tube 02 and the spontaneous combustion sample tube 15.

The insulation upper cover plate 01 of rerum natura sample tube 02 and lower cover 09 adopt the very little through-hole foam aluminium sheet aluminium coating paper tinsel of thermal conductivity to make, and be airtight to guarantee it.

The ventilative insulation upper cover plate 16 of spontaneous combustion sample tube 15 and lower cover 11 adopt the foamed aluminium board manufacturing of the very little through hole (breathing freely) of thermal conductivity.

Base plate in the middle of two sample tubes is installed sample tube temperature sensor 10, is used for measuring sample tube temperature T _R

Programmable power supply 17(with serial communication interface and power measurement function sees Fig. 4) with two metal electrodes 08 of electrical-heating film 05 with 12 with link to each other, be used for control and metering heating power.

With physical property measurement sample S ₁ Central temperature sensor 04, spontaneous combustion specimen S ₂ Central temperature sensor 13 and sample tube temperature sensor 10 link to each other with the Temperature sampler 18 with serial communication function, are used for temperature data acquisition.

PC or man-machine interface (HMI) 19 and programmable power supply 17 and Temperature sampler 18 be by the serial communication interface (see figure 3) that links to each other, and is used for setup parameter, drives the heating power data that programmable power supply transmits from programmable power supply 17 respectively according in time linear rule heating, record, storage and the temperature data that transmits from Temperature sampler 18.

Temperature sensor 04, temperature sensor 10 and temperature sensor 13 adopt armouring minisize thermoelectric resistance (RTD) temperature sensor; Have programmable power supply 17 serial communication interface and the power measurement function and adopt the PMS3000 type direct current programmable power supply with communication interface and power measurement function of inferior sharp company; The 3 passage resistance and temperature acquisition module I-7033 with serial communication function of the deep lattice of Temperature sampler 18 employings company; Man-machine interface (HMI) 19 adopts the touch man-machine interface of the Kunlun MCGS-Tpc7062 of on-state company, and it has with function, the usefulness programmed scripts language of PMS3000 type direct current programmable power supply and resistance and temperature acquisition module I-7033 serial communication realizes data acquisition, processing and formation closed loop PID temperature control function.

Embodiment two is with embodiment one difference:

Make rerum natura sample tube 02 and spontaneous combustion sample tube 15 with high-purity red copper machining, electrical-heating film 05 adopts the constantan etching to make, temperature sensor 04, temperature sensor 10 and temperature sensor 13 adopt armouring micro thermocouple (K type) temperature sensor, have programmable power supply 17 serial communication interface and the power measurement function and adopt the IT6720 type direct current programmable power supply with communication interface and power measurement function of Ai De Ces Co.,Ltd; The 8 path thermocouple temperature collect module I-7018 with serial communication function of the deep lattice of Temperature sampler 18 employings company; Man-machine interface (HMI) 19 adopts and shows the touch man-machine interface of the SA-7A of control company, and it has with function, the usefulness C language of IT6720 type direct current programmable power supply and Thermocouple Temperature Acquisition module I-7018 serial communication realizes data acquisition, processing and formation closed loop PID temperature control function.

Embodiment three is with embodiment one difference:

On the basis of one of embodiment, use man-machine interface instead PC, additional USB/RS485 communication converter based on the PL2102 chip, with PMS3000 type direct current programmable power supply and resistance and temperature acquisition module I-7033 serial communication, can realize data acquisition, processing and formation closed loop PID temperature control function with the C language at PC.

Adopt in above-mentioned three kinds of systems any one to measure the method for combustible granules apparent heat rerum natura and self-ignition temperature simultaneously, comprise the calorimetric calibration and test two steps:

The calorimetric calibration:

1.) at first do not loading measured object property testing sample S ₁03 and spontaneous combustion specimen S ₂Under 14 the situation, carry out the calorimetric reference test;

2.) turn on the power switch, give programmable power supply 17, Temperature sampler 18 and man-machine interface 19 power supplies, man-machine interface 19 set test temperature rise rate (representative value be 1-3 ℃/min); Start programmable power supply 17 heating, record sample tube temperature over time curve and heating power with variation of temperature curve P ₀(T), as the benchmark of heating power;

3.) close all power switches, allow instrument be cooled to environment temperature in order to the usefulness of test.

Test:

1.) with measured object property testing sample S ₁03 and spontaneous combustion specimen S ₂14 are loaded into respectively in rerum natura sample tube 02 and the spontaneous combustion sample tube 15;

2.) turn on the power switch, give programmable power supply 17, Temperature sampler 18 and man-machine interface 19 power supplies, man-machine interface 19 set test temperature rise rate (representative value be 1-3 ℃/min); Start programmable power supply 17 heating, record sample tube temperature T _R, physical property measurement sample temperature T _1cTemperature T with the spontaneous combustion specimen _2cAnd heating power is with variation of temperature curve P (T), at this moment

Be the heating power that adds every group of sample;

3.) after spontaneous combustion sample generation spontaneous combustion or the sample tube reached predetermined maximum temperature (for coal, representative value is 150 ℃), then control programmable power supply 17 and stop heating, preserve temperature and power data on the man-machine interface 19;

4.) record data are analyzed, when heating process reaches nominal situation, T _1R-T _1cRemain unchanged, this moment can basis Calculate thermal diffusion coefficient a, according to Calculate thermal capacity ρ c, according to the thermal conductivity λ of λ=ρ ca calculation sample; The temperature rise curve at two sample centers of contrast can be found out its burble point and corresponding temperature thereof, and this temperature namely is the self-ignition temperature of sample; Calculate the temperature rise rate of two samples when catching fire from two temperature rise curves

With Then can basis $Q_V\left(T\right)=\mathrm{\&rho;c}(\frac{{\&PartialD;T}_2}{\&PartialD;\mathrm{\&tau;}}-\frac{{\&PartialD;T}_1}{\&PartialD;\mathrm{\&tau;}})=\mathrm{\&rho;c}(\frac{{\&PartialD;T}_2}{\&PartialD;\mathrm{\&tau;}}-A)$ Calculate the volume heat generation rate Q of spontaneous combustion sample _V(T).

Claims (1)

1. system that measures combustible granules apparent heat rerum natura and self-ignition temperature simultaneously is characterized in that: comprising:

Rerum natura sample tube (02) and the spontaneous combustion sample tube (15) of tubulose and the base plate that both are connected as one of the tubulose made from highly heat-conductive material, described base plate places with thermo electric material and makes on the electrical-heating film (05);

The back up pad (06) that adopts heat preservation plate material to make below the electrical-heating film supports, and draw from back up pad (06) below two metal electrode (08) and (12);

Insulation lower cover (09) sealing that the end opening of rerum natura sample tube (02) is made with the gas impermeable material of insulation;

The insulation lower cover made from the gas permeable material of insulation at the end opening of spontaneous combustion sample tube (15) (11) seals;

Tested physical property measurement sample (03) and spontaneous combustion specimen (14) are loaded into respectively in rerum natura sample tube (02) and the spontaneous combustion sample tube (15), and are provided with physical property measurement sample central temperature sensor (04) and spontaneous combustion specimen central temperature sensor (13) respectively therein;

Insulation upper cover plate (01) sealing made from the gas impermeable material of insulation suitable for reading of rerum natura sample tube (02), insulation upper cover plate (16) sealing made from the gas permeable material of insulation suitable for reading of spontaneous combustion sample tube (15);

Base plate in the middle of two sample tubes is equipped with sample tube temperature sensor (10);

Programmable power supply (17) with serial communication interface and power measurement function and two metal electrodes (08) of electrical-heating film (05) and (12) with link to each other;

Physical property measurement sample central temperature sensor (04), spontaneous combustion specimen central temperature sensor (13) and sample tube temperature sensor (10) link to each other with the Temperature sampler with serial communication function (18);

PC or man-machine interface (19) link to each other by serial communication interface respectively with programmable power supply (17) and Temperature sampler (18).

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