CN104165823A - Method and device for measuring viscosity of products generated by splitting of hydrocarbon fuel at high temperature and under high pressure on line - Google Patents

Abstract

The invention relates to a device and a method for measuring the viscosity of products generated by splitting of hydrocarbon fuel at high temperature and under high pressure on line. The device comprises an oil storage tank, a high-pressure constant-flow pump mass flowmeter, a heating pipe, a viscosity measurement pipe, a density measurement pipe, a condenser and a back pressure valve. The method is used for measuring the viscosity of splitting products according to a viscosity expression based on a turbulent flow condition in a flow state and by the device, and in the viscosity expression, delta p is online collected differential pressure value of two ends of the viscosity measurement pipe, Qm is the online collected mass flow rate of hydrocarbon fuel, pho is the density of the products generated by splitting of hydrocarbon fuel, and A is the flow field coefficient of a thin pipe and is obtained by calibration on standard gas with known viscosity. The measurement method and the matched measurement device are adopted to avoid adverse effects of high-temperature coking on a pipeline in a hydrocarbon fuel splitting process and can be used for safely carrying out online measurement on the viscosity of the products generated by splitting of hydrocarbon fuel at high temperature and under high pressure.

Description

On-line determination method and the determinator of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity

Technical field

The invention belongs to Engineering Thermophysics and fuel physical property measurement technical field, particularly a kind of viscosity measurement of hydrocarbon fuel pyrolysis product and supporting determinator.

Background technology

The hydrocarbon fuel of scramjet engine technical requirement certain flow heats and undergoes phase transition and cracking reaction in small-bore cooling duct, absorbs the heat of engine chamber, thereby realizes the cooling of engine, and cooling duct internal diameter is generally below 3mm.Fuel molecule phase transformation and reaction at high temperature, the phase of system, component, molecular weight, density and viscosity constantly change, and because the cracking reaction of hydrocarbon fuel is thermonegative reaction, be difficult to reach chemical equilibrium, so the density of system, viscosity and flow velocity are also subject to the impact of heat time.And in engineering test, along with the variation of fuel mass rate in pipe, fuel bringing-up section residence time in pipe also can change.In order to ensure the safe operation of engine, must there is clear and definite understanding to the thermophysical property of hydrocarbon fuel.The performance data of fuel, as specific heat, density, viscosity, surface tension and critical parameters have vital role to the design cycle of the performance condition of prediction component and shortening engine, and viscosity is one of important physical character of fluid, the data that analysis and calculation fuel-pyrolysis gas heat transfer characteristic, flow characteristics must be known, at engineering discipline widely, and playing very important effect in the character of determining fluid, the on-line measurement that therefore realizes viscosity under different engineering specifications is significant.

About the on-line determination of viscosity, tubule method is conventional method, and its measuring principle is identical with laboratory determined off-line principle, is all based on Bo Shi law: in formula, f is flow field coefficient, can be calculated by the size of tubule, in actual viscosity measurement, also can be demarcated and be obtained by viscosity standard fluid, and Δ p is the pressure differential at tubule two ends, Q _vvolumetric flow rate for the tubule of flowing through.Adopting the tubule method on-line determination viscosity most important is to guarantee that fluid is laminar condition, when yet hydrocarbon fuel cracking reaction occurs, micro-molecular gas increases, meanwhile, coking reaction also can produce, rely on low flow velocity to maintain Laminar Flow and will produce a large amount of cokings, then may cause even equipment scaling loss of line clogging.The viscosity on-line determination of the pyrolysis gas that therefore, the tubule method based on Bo Shi law produces under high-temperature and high-pressure conditions for hydrocarbon fuel is also inapplicable.Also without a kind of method, can realize at present the on-line determination of flowing gas viscosity in hydrocarbon fuel cracking reaction process.

Summary of the invention

The present invention is directed to the deficiency that prior art exists, provide a kind of on-line determination method and determinator of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity, to realize the on-line determination of hydrocarbon fuel pyrolysis product viscosity.

Technical conceive of the present invention is: for the concrete features of hydrocarbon fuel cracking, i.e. and high temperature, high pressure, cracking process is complicated, change of component, flow velocity is fast (turbulence state) etc. very, adopts the tubule method based under flow state turbulent-flow conditions to carry out on-line determination.According to the mensuration of on-way resistance, obtain resistance coefficient, then according to the relation of resistance coefficient under turbulent-flow conditions and Reynolds number, and then the viscosity of acquisition fluid.

Based on above-mentioned technical conceive, the present invention adopts and revises smooth pipe formula calculate and measurement viscosity, and principle is as follows:

By straight tube resistance gauge formula:

$\frac{\mathrm{\Δp}}{\mathrm{\ρ}}=\mathrm{\λ}\frac{l}{d}\frac{{\stackrel{\‾}{u}}^2}{2}---\left(1\right)$

By $\stackrel{\‾}{u}=\frac{Q_m}{\mathrm{A\ρ}}=\frac{{4Q}_m}{{\mathrm{\πd}}^2\mathrm{\ρ}}$ :

$\mathrm{\Δp}=\mathrm{\λ}\frac{l}{d}\frac{{\stackrel{\‾}{u}}^2}{2}=8\mathrm{\λ}\frac{Q_m^{2}l}{{\mathrm{\π}}^2{d}^5\mathrm{\ρ}}---\left(2\right)$

Above-mentioned (1) formula, (2) formula are from < < Principles of Chemical Engineering (the 4th edition) > > (Wang Zhikui; Liu Liying; Liu Wei .[M]. the .2010 of Chemical Industry Press, 5.)

In above-mentioned (1) formula, (2) formula:

Q _m: mass rate

Δ p: be short tube used two ends differential pressure,

L: be short tube length used

D: be short tube diameter used

ρ: be short tube inner fluid density used

for short tube inner fluid mean flow rate used

λ: pipeline friction factor

According to the smooth pipe formula of turbulent flow:

$\mathrm{\&lambda;}=\frac{0.3164}{{\mathrm{Re}}^{0.25}}=\frac{0.3164}{{\left(\frac{{4Q}_m}{\mathrm{\&pi;d\&mu;}}\right)}^{0.25}}---\left(3\right)$

Above-mentioned (3) formula is from < < Principles of Chemical Engineering (the 4th edition) > > (Wang Zhikui; Liu Liying; Liu Wei .[M]. the .2010 of Chemical Industry Press, 5.)

When pipeline one regularly, the rubbing characteristics of pipeline be one quantitatively.Because the stainless-steel tube tube wall using is smooth, therefore adopt turbulent flow smooth pipe formula, (3) substitution (2) formula is obtained:

$\mathrm{\&Delta;p}=\frac{0.2414l}{d^{4.75}}\frac{Q_m^{1.75}}{\mathrm{\&rho;}}{\mathrm{\&mu;}}^{0.25}---\left(4\right)$

Note a is defined as to tubule flow field coefficient, by known gas, demarcates and can obtain A value.

The viscosity formula of turbulence state is as follows:

$\mathrm{\&mu;}={\left(\frac{\mathrm{\&Delta;p}\&CenterDot;\mathrm{\&rho;}}{A\&CenterDot;Q_m^{1.75}}\right)}^4---\left(5\right)$

(5) the tubule flow field coefficient A in formula demarcated with the calibrating gas of known-viscosity before measuring unknown fluid, and scaling method is as follows:

Control Re>4000, by (5) formula, obtained

$A=\frac{\mathrm{\&Delta;p}\&CenterDot;\mathrm{\&rho;}}{Q_m^{1.75}{\mathrm{\&mu;}}^{0.25}}---\left(6\right)$

In formula, μ, ρ is respectively viscosity, the density of known gas, can table look-up and obtain (data in the present invention are looked into the software from NIST Superstrap), Q _mfor known gas mass rate, by mass flowmeter, obtained online Δ p: for short tube used two ends differential pressure, by pressure difference transmitter, obtained online.

According to the viscosity formula of technical conceive of the present invention and turbulence state, the technical scheme of the on-line determination apparatus and method of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity of the present invention is as follows:

The on-line determination device of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity of the present invention, comprises storage tank, high pressure constant flow pump mass flowmeter, heating tube, viscosimetric analysis pipe, tensimeter, orifice plate pressure vessel, condenser and the counterbalance valve of the second pressure difference transmitter is installed; The liquid feeding end of described high pressure constant flow pump is connected with storage tank by pipe fitting, the outlet end of high pressure constant flow pump is connected with the inlet of mass flowmeter by pipe fitting, is provided with the retaining valve that stops hydrocarbon fuel to be back to high pressure constant flow pump on the pipe fitting that connects high pressure constant flow pump outlet end and mass flowmeter inlet; The entrance point of described heating tube is connected with the liquid outlet of mass flowmeter by pipe fitting, the endpiece of heating tube is connected with the entrance point of viscosimetric analysis pipe by pipe fitting, the endpiece of heating tube is provided with thermopair, viscosimetric analysis pipe is equipped with the first pressure difference transmitter, and the two ends of described the first pressure difference transmitter are connected with the two ends of viscosimetric analysis pipe respectively; The entrance point of described orifice plate pressure vessel is connected with the endpiece of viscosimetric analysis pipe, and the endpiece of orifice plate pressure vessel is connected with the entrance point of condenser, and described tensimeter is arranged on the front end of orifice plate pressure vessel, and the endpiece of described condenser is connected with counterbalance valve.

The on-line determination device of above-mentioned hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity, the dimensional parameters of orifice plate pressure vessel is shown in patent CN102507375 B, described the second pressure difference transmitter is for the pressure reduction before and after measuring diaphragm pressure vessel aperture plate.

The on-line determination device of above-mentioned hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity, the internal diameter of its viscosimetric analysis pipe is 1mm～4mm, length is 20cm～100cm.

The on-line determination method of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity of the present invention, adopts the viscosity expression formula based under flow state turbulent-flow conditions use above-mentioned on-line determination device to measure, in described viscosity expression formula, the differential pressure value at the viscosimetric analysis pipe two ends that Δ p is online acquisition, Q _mfor the mass rate of the hydrocarbon fuel of online acquisition, ρ is the density of hydrocarbon fuel pyrolysis product, and A is tubule flow field coefficient, with the calibrating gas of known-viscosity, demarcates and obtains.

The on-line determination method of above-mentioned hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity, operation steps is as follows:

1. open high pressure constant flow pump, make tested hydrocarbon fuel enter heating tube by the mass rate of setting, and with the mass rate Q of mass flow meter measurement hydrocarbon fuel _m;

2. open the heating system of heating tube, adjust cracking temperature and cracking pressure to the temperature and pressure requiring, make to undergo phase transition and cracking reaction through the hydrocarbon fuel of heating tube;

3. use the temperature of thermocouple measurement hydrocarbon fuel pyrolysis product, with the first differential pressure transmitter, measure the differential pressure value Δ p at viscosimetric analysis pipe two ends, with the pressure of gauge measurement hydrocarbon fuel pyrolysis product, with the pressure reduction before and after the second pressure difference transmitter measuring diaphragm pressure vessel aperture plate; By data acquisition unit by the mass rate Q that is not less than the frequency online acquisition hydrocarbon fuel of 1 time/s _m, the temperature and pressure of hydrocarbon fuel pyrolysis product, the pressure reduction before and after the differential pressure value Δ p at viscosimetric analysis pipe two ends and orifice plate pressure vessel aperture plate.

By the 3. mass rate Q of the hydrocarbon fuel of online acquisition of step _m, the differential pressure value Δ p at viscosimetric analysis pipe two ends and the mass rate Q of the hydrogen fuel by online acquisition _mwith pressure reduction before and after orifice plate pressure vessel aperture plate and the hydrocarbon fuel pyrolysis product density p that obtains is brought into by calculating the viscosity that can obtain tested hydrocarbon fuel pyrolysis product.

Obtain the method for hydrocarbon fuel pyrolysis product density p: by the disclosed method computing of patent CN 102507375 B for the pressure reduction before and after the mass rate of the hydrocarbon fuel of online acquisition and orifice plate pressure vessel aperture plate, can obtain the density p of hydrocarbon fuel pyrolysis product.

The on-line determination method of above-mentioned hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity, tested hydrocarbon fuel enters heating tube with the mass rate of 0.1g/s～5g/s.

The on-line determination method of above-mentioned hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity, the cracking temperature of hydrocarbon fuel is that 450 ℃～800 ℃, cracking pressure are 0.1MPa～6MPa.

The on-line determination method of above-mentioned hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity, its cracking temperature is adjusted by heating system, and cracking pressure is adjusted by counterbalance valve.The pressure of described hydrocarbon fuel pyrolysis product equals cracking pressure, and the temperature of hydrocarbon fuel pyrolysis product equals cracking temperature.

Compared with prior art, the present invention has following beneficial effect:

1, the on-line determination that the present invention is hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity provide a kind of practicable method and with the supporting device of the method, use assay method of the present invention and supporting determinator, avoid the harmful effect that in hydrocarbon fuel cracking process, high-temperature coking causes pipeline, can realize safely the on-line determination of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity.

2, assay method of the present invention and supporting determinator, Media density in the engineering research of scramjet engine Active Cooling System and the on-line measurement problem of viscosity have been solved, and then the mean molecular weight that can realize fuel-pyrolysis gas calculates, in pipe with small pipe diameter passage, the performance evaluation of the mobile process of heterogeneous reaction, plays an important role to engine Active Cooling System Design.

3, the on-line determination apparatus structure of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity of the present invention is simple, is convenient to processing and fabricating, and assay method is simple, easy operating and grasp.

Accompanying drawing explanation

Fig. 1 is the structural representation of the on-line determination device of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity of the present invention.

In figure, 1-storage tank, 2-high pressure constant flow pump, 3-retaining valve, 4-mass flowmeter, 5-heating tube, 6-AC power, 7-thermopair, 8-viscosimetric analysis pipe, 9-the first differential pressure transmitter, 10-orifice plate pressure vessel, 11-tensimeter, 12-the second pressure difference transmitter, 13-condenser, 14-counterbalance valve.

Embodiment

Below by embodiment, on-line determination device and the assay method of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity of the present invention are described further.

Embodiment 1

In the present embodiment, the structure of the on-line determination device of described hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity as shown in Figure 1, comprises storage tank 1, high pressure constant flow pump 2, mass flowmeter 4, heating tube 5, tensimeter 11, viscosimetric analysis pipe 8, the orifice plate pressure vessel 10 that the second pressure difference transmitter 12 is installed, condenser 13 and counterbalance valve 14; The liquid feeding end of described high pressure constant flow pump 2 is connected with storage tank 1 by pipe fitting, the outlet end of high pressure constant flow pump 2 is connected with the inlet of mass flowmeter 4 by pipe fitting, is provided with the retaining valve 3 that stops hydrocarbon fuel to be back to high pressure constant flow pump on the pipe fitting that connects high pressure constant flow pump outlet end and mass flowmeter inlet; The entrance point of described heating tube 5 is connected with the liquid outlet of mass flowmeter 4 by pipe fitting, and the endpiece of heating tube 5 is connected with the entrance point of viscosimetric analysis pipe 8 by pipe fitting, and the endpiece of heating tube 5 is provided with thermopair 7, and heating tube two ends are connected with AC power 6; Viscosimetric analysis pipe 8 is equipped with the first pressure difference transmitter 9, and the two ends of described the first pressure difference transmitter are connected with the two ends of viscosimetric analysis pipe respectively; The entrance point of described orifice plate pressure vessel 10 is connected with the endpiece of viscosimetric analysis pipe 8, the endpiece of orifice plate pressure vessel 10 is connected with the entrance point of condenser 13, described tensimeter 11 is arranged on the front end of orifice plate pressure vessel, the endpiece of described condenser 13 is connected with counterbalance valve 14, water inlet is established in condenser 13 bottoms, and top sets out the mouth of a river.

In the present embodiment, heating tube 5, viscosimetric analysis pipe 8, orifice plate pressure vessel 10 and all connecting tubes are made by stainless steel.

Embodiment 2

The present embodiment is demarcated tubule flow field coefficient A, and step is as follows:

With the nitrogen of purity 99.99%, demarcate, viscosity, the density of nitrogen of tabling look-up to obtain, passes into nitrogen described in embodiment 1 in structure on-line determination device, adjusts different temperature, measures the mass rate Q of nitrogen _mand the differential pressure Δ p at viscosimetric analysis pipe 8 two ends under different temperatures, by the viscosity of nitrogen, density and measure the mass rate Q of gained _m, differential pressure Δ p brings following formula into:

calculate A value, result of calculation is in Table 1.Get the mean value of repeatedly measuring for the viscosimetric analysis of aviation kerosene High Temperature High Pressure pyrolysis product.

The demarcation of table 1 tubule flow field coefficient A

Note: 1, in on-line determination device, the internal diameter of heating tube is 2mm, and length is 100cm, and the internal diameter of viscosimetric analysis pipe 8 is 2mm, and length is 20cm.

2,, in table 1, E-03 is * 10 ^-3, E-04 is * 10 ^-4, E-05 is * 10 ^-5, E+11 is * 10 ¹¹, for example, 1.14E-03=1.14 * 10 ^-3, 7.09E-04=7.09 * 10 ^-4, 1.83E-05=1.83 * 10 ^-5, 5.83E+11=5.83 * 10 ¹¹.

Embodiment 3

Described in the present embodiment employing embodiment 1, the determinator of structure is, the tubule flow field coefficient that embodiment 2 demarcates carries out on-line determination to aviation kerosene High Temperature High Pressure pyrolysis product viscosity.

Hydrocarbon fuel: aviation kerosene;

Mass rate Q _m: 1g/s;

Cracking pressure p: 1.0MPa;

Viscosimetric analysis bore: 2mm; Length: 20cm;

The internal diameter of heating tube: 2mm, length: 100cm;

Cracking temperature: in Table 2.

Concrete operation step is as follows:

1. open high pressure constant flow pump 2, make tested hydrocarbon fuel enter heating tube 5 by the mass rate of setting, and with mass flowmeter 4, measure the mass rate Q of hydrocarbon fuel _m;

2. open the AC power 6 of heating tube 5, adjust cracking temperature and cracking pressure to the temperature and pressure requiring, make to undergo phase transition and cracking reaction through the hydrocarbon fuel of heating tube;

3. with thermopair 7, measure the temperature of hydrocarbon fuel pyrolysis product, with the first differential pressure transmitter 9, measure the differential pressure value Δ p at viscosimetric analysis pipe 8 two ends, with the pressure of gauge measurement hydrocarbon fuel pyrolysis product, with the pressure reduction before and after the second pressure difference transmitter 12 measuring diaphragm pressure vessel 10 aperture plate; By data acquisition unit (HIOKI LR8500) by the mass rate Q that is not less than the frequency online acquisition hydrocarbon fuel of 1 time/s _m, the temperature and pressure of hydrocarbon fuel pyrolysis product, the pressure reduction before and after the differential pressure value Δ p at viscosimetric analysis pipe two ends and orifice plate pressure vessel 10 aperture plate;

4. be calculated as follows the viscosity of tested hydrocarbon fuel pyrolysis product,

$\mathrm{\&mu;}={\left(\frac{\mathrm{\&Delta;p}\&CenterDot;\mathrm{\&rho;}}{A\&CenterDot;Q_m^{1.75}}\right)}^4$

In formula, the differential pressure value at the viscosimetric analysis pipe two ends that Δ p is online acquisition, Q _mmass rate for the hydrocarbon fuel of online acquisition, ρ is the density of hydrocarbon fuel pyrolysis product, pressure reduction before and after the mass rate of the hydrocarbon fuel of online acquisition and orifice plate pressure vessel 10 aperture plate is obtained to (in Table 2) with the disclosed method computing of patent CN 102507375 B, A is tubule flow field coefficient, in embodiment 2, demarcates and obtains.

Measurement result sees the following form:

Viscosity number under the different cracking pressure of table 2, cracking temperature, mass rate

Embodiment 4

The tubule flow field coefficient that described in the present embodiment employing embodiment 1, determinator, embodiment 2 demarcate carries out on-line determination to aviation kerosene High Temperature High Pressure pyrolysis product viscosity.

Hydrocarbon fuel: aviation kerosene;

Mass rate Q _m: 1g/s;

Cracking pressure p: 1.5MPa;

Viscosimetric analysis bore: 1mm; Length: 40cm;

The internal diameter of heating tube: 2mm, length: 100cm;

Cracking temperature: in Table 3.

Concrete operation step is identical with embodiment 3.

Measurement result sees the following form:

Viscosity number under the different cracking pressure of table 3, cracking temperature, mass rate

Embodiment 5

The tubule flow field coefficient that described in the present embodiment employing embodiment 1, determinator, embodiment 2 demarcate carries out on-line determination to aviation kerosene High Temperature High Pressure pyrolysis product viscosity.

Hydrocarbon fuel: aviation kerosene;

Mass rate Q _m: 1g/s;

Cracking pressure p: 3.5MPa;

Viscosimetric analysis bore: 3mm; Length: 80cm;

The internal diameter of heating tube: 2mm, length: 100cm;

Cracking temperature: in Table 4.

Concrete operation step is identical with embodiment 3.

Measurement result sees the following form:

Viscosity number under the different cracking pressure of table 4, cracking temperature, mass rate

Embodiment 6

The tubule flow field coefficient that described in the present embodiment employing embodiment 1, determinator, embodiment 2 demarcate carries out on-line determination to aviation kerosene High Temperature High Pressure pyrolysis product viscosity.

Hydrocarbon fuel: aviation kerosene;

Mass rate Q _m: 2.5g/s;

Cracking pressure p: 1.5MPa;

Viscosimetric analysis bore: 2mm; Length: 20cm;

The internal diameter of heating tube: 2mm, length: 100cm;

Cracking temperature: in Table 5.

Concrete operation step is identical with embodiment 3.

Measurement result sees the following form:

Viscosity number under the different cracking pressure of table 5, cracking temperature, mass rate

Claims (6)

1. the on-line determination device of a hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity, comprise storage tank (1), mass flowmeter (4), heating tube (5), tensimeter (11), the orifice plate pressure vessel (10) that the second pressure difference transmitter (12) is installed, condenser (13), counterbalance valve (14), it is characterized in that also comprising high pressure constant flow pump (2) and viscosimetric analysis pipe (8); The liquid feeding end of described high pressure constant flow pump (2) is connected with storage tank (1) by pipe fitting, the outlet end of high pressure constant flow pump (2) is connected with the inlet of mass flowmeter (4) by pipe fitting, is provided with the retaining valve (3) that stops hydrocarbon fuel to be back to high pressure constant flow pump on the pipe fitting that connects high pressure constant flow pump outlet end and mass flowmeter inlet; The entrance point of described heating tube (5) is connected with the liquid outlet of mass flowmeter (4) by pipe fitting, the endpiece of heating tube (5) is connected with the entrance point of viscosimetric analysis pipe (8) by pipe fitting, the endpiece of heating tube (5) is provided with thermopair (7), viscosimetric analysis pipe (8) is equipped with the first pressure difference transmitter (9), and the two ends of described the first pressure difference transmitter are connected with the two ends of viscosimetric analysis pipe respectively; The entrance point of described orifice plate pressure vessel (10) is connected with the endpiece of viscosimetric analysis pipe (8), the endpiece of orifice plate pressure vessel (10) is connected with the entrance point of condenser (13), described tensimeter (11) is arranged on the front end of orifice plate pressure vessel (10), and the endpiece of described condenser (13) is connected with counterbalance valve (14).

2. the on-line determination device of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity according to claim 1, the internal diameter that it is characterized in that viscosimetric analysis pipe (8) is 1mm～4mm, length is 20cm～100cm.

3. an on-line determination method for hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity, is characterized in that adopting the viscosity expression formula based under flow state turbulent-flow conditions right to use requires the device described in 1 or 2 to measure, in described viscosity expression formula, and the differential pressure value at the viscosimetric analysis pipe two ends that Δ p is online acquisition, Q _mfor the mass rate of the hydrocarbon fuel of online acquisition, ρ is the density of hydrocarbon fuel pyrolysis product, and A is tubule flow field coefficient, with the calibrating gas of known-viscosity, demarcates and obtains.

4. the on-line determination method of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity according to claim 3, is characterized in that operation steps is as follows:

1. open high pressure constant flow pump (2), make tested hydrocarbon fuel enter heating tube (5) by the mass rate of setting, and with mass flowmeter (4), measure the mass rate Q of hydrocarbon fuel _m;

2. open the heating system of heating tube (5), adjust cracking temperature and cracking pressure to the temperature and pressure requiring, make to undergo phase transition and cracking reaction through the hydrocarbon fuel of heating tube;

3. use thermopair (7) to measure the temperature of hydrocarbon fuel pyrolysis product, with the first differential pressure transmitter (9), measure the differential pressure value Δ p at viscosimetric analysis pipe (8) two ends, with the pressure of gauge measurement hydrocarbon fuel pyrolysis product, with the pressure reduction before and after the second pressure difference transmitter (12) measuring diaphragm pressure vessel (10) aperture plate; By data acquisition unit by the mass rate Q that is not less than the frequency online acquisition hydrocarbon fuel of 1 time/s _m, the temperature and pressure of hydrocarbon fuel pyrolysis product, the pressure reduction before and after the differential pressure value Δ p at viscosimetric analysis pipe two ends and orifice plate pressure vessel (10) aperture plate.

5. the on-line determination method of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity according to claim 4, is characterized in that tested hydrocarbon fuel enters heating tube (5) with the mass rate of 0.1g/s～5g/s.

6. according to the on-line determination method of hydrocarbon fuel High Temperature High Pressure pyrolysis product viscosity described in claim 4 or 5, the cracking temperature that it is characterized in that hydrocarbon fuel is that 450 ℃～800 ℃, cracking pressure are 0.1MPa～6MPa.