SY 7517-1992 Determination of specific heat capacity of crude oil Adiabatic calorimetry SY7517-1992 Standard download decompression password: www.bzxz.net

After the cleanup and rectification of the standards of the petroleum and natural gas industry of the People's Republic of China, the standard number of this standard is SY/T7517-94. After the rectification, a new text was published, and the 1992 version is still used. Method for determination of specific heat capacity of crude oil
Adiabatic calorimetry
Published on April 27, 1992
Ministry of Energy of the People's Republic of China
SY 7517-92
Implemented on October 1, 1992
Subject content and scope of application
Standards of the Petroleum and Natural Gas Industry of the People's Republic of China Method for determination of specific heat capacity of crude oil Adiabatic calorimetry This standard specifies the method for determining the specific heat capacity of crude oil using the adiabatic base heat method. This standard is applicable to the determination of the specific heat capacity of crude oil in the temperature range from 273K to the initial distillation point at room temperature. 2 Reference standards
GB255 Determination method of petroleum products
GB5to Determination method of freezing point of petroleum products
GB4756 Sampling method of petroleum and liquid petroleum products 3 Terms and symbols
3.1 Calorimetric system
SY751792
Refers to each part to which the heat to be measured can be distributed. Including calorimetric container, sample heater, standard pin resistance thermometer and sample,
3.2 Calorimetric experimental environment
Refers to the environment within the outer screen of the calorimeter,
3.3 Adiabatic calorimetryWww.bzxZ.net
A method for determining specific heat capacity that eliminates the heat exchange between the calorimetric system and the calorimetric experimental environment and keeps the calorimetric system and the ambient temperature equal at any moment during the calorimetric process.
3.4 ​​Initial temperature T1 and final temperature T
Assume that the hottest system is in thermal equilibrium state 1, a certain amount of energy is added to make the system warm up and form a new thermal equilibrium state 2. In the thermodynamic process, the temperature of state 1 is the initial temperature T1 and the temperature of state 2 is the final temperature 7.4 Principle
Under adiabatic conditions, add electrical energy Q. to a crude oil sample of mass m to make it produce a certain temperature rise △? , and calculate the specific heat capacity of the crude oil sample from the measured Q, A7, proof. The principle expression is Cp
Wu Zhong: Ca——Specific heat capacity of crude oil, J < kg·) Q-Added electrical energy, i
47—Experimental liter, K,
…Original leakage test mass, name.
5 Adiabatic heating device
5.1 The device structure is shown in Figure 1
5.2 Performance indicators
5.2.1 The resolution of the measurement system is 0.IV.
Approved by the Ministry of Energy of the People's Republic of China on April 27, 1992 Q.
+++++(1)
Implemented on October 1, 1992
True density machine line
SY 7517--92
Figure 1 Adiabatic calorimeter
Temperature difference recorder
Inner screen temperature control device
Outer screen temperature control device
State thermal power supply
Time measuring and controlling instrument
Digital electric meter
Interface circuit
Potentiometer
Wenle power supply
1-Resistance-temperature ratio; 3-Sample heater; 3-Calorific container; 4-Thermocouple, 5-Inner insulation screen, 6-Outer insulation screen, 7-Thermal screen heater: 8-Leading wire! 9- Vacuum chamber; 10- Connection electrode 5.2.2 The temperature change rate of measurement is less than 6×10-3K/min. 5.2.3 The timing error is less than 1×10-1s.
5.2.4 The vacuum degree of the system is not less than 1.3×10\Pa 5.3 Component requirements
5.3.1 Calorimetric container: Made of 99.99% pure convex silver or purple pin, gold-plated, with a wall thickness of no more than 0.3mm, and a volume range of 20 to 100m1. The shell is cylindrical, with a hemispherical top and bottom. The top is equipped with a sample moon with a threaded cover and a sealing gasket in the center, and a concave central tube well in the center of the bottom, with a heat sink welded on the tube well. Its structure is shown in Figure 2: 4
Figure 2 Schematic diagram of the structure of the calorimetric container
1—porcelain body, 2—threaded part: 3—sealed part 1—thermal plate, 5—central tube SY 7517-92
5.3.2 Standard platinum resistance thermometer: the temperature accuracy is not less than 0.01K. 5.3.3 Differential thermopile: no less than 4 pairs of nickel-chromium-copper thermocouples are connected. 5.3.4 Vacuum dryer, which can withstand a vacuum degree of 1.3×10-Pa. 5.3.5 Cold bath: Dewar flask filled with refrigerant. 6. Reagents and experimental materials
6.1 Standard substances
n-heptane (GR) ethylene glycol (GR); double distilled water (freshly distilled). 6.2. Detergent
Crude oil (CP) or other organic solvents, anhydrous ethanol (AR) s6.3 Refrigerant
Ethanol-in ice; saturated salt water-in ice.
Experimental preparation
7.1 Sample treatment
7.1.1 Collect oil samples according to GB4756.
7.1-2 Put the oil into a water bath 15K higher than its freezing point (GB510) to melt and stir evenly, and divide it into 3 250ml wide-mouth bottles, seal them, and keep them in a book.
7.2 Washing of calorimetric container
Wash with ether or other organic solvents, rinse with anhydrous ethanol 2 to 3 times after washing, blow dry with hot air, put it in a drying oven at 383K for F2h, weigh it at low temperature, and accurately weigh its mass m1. The mass of the calorimeter in each experiment should be within +5×10-3g of the previous one. Otherwise, it should be washed freshly and then repeated.
7.3 Sample loading and weighing
Take a bottle of sample and put it into a water bath 15K higher than the freezing point of the sample to melt. (When calibrating the instrument, take any standard substance in Section 6.1 as the sample). Use a syringe to inject the sample equivalent to 190 kg of the calorimeter container into the calorimeter container measured in Section 8.1. Seal it and weigh its weight m2 in advance.
The weight of the sample is:
The weight of the sample, kg;
Where: m--
m1.—The weight of the calorimeter container, k.
.4 Leakage detection
The sum of the weight of the sample and the calorimeter container, k.
Put the sealed calorimetric container in a vacuum dryer, connect the vacuum pump, and keep it at a vacuum degree of not less than 1.3×t0~1Pa for 30 minutes before taking it out and weighing it. The weight loss does not exceed 5×10-3, which is qualified. Otherwise, reseal it. 7.5 Install the inner screen
Insert the standard Yabolai resistance thermometer and sample heater into the central tube well of the calorimetric tube, and then evenly distribute and stick a group of thermopiles on the corresponding positions of the inner wall of the inner exhibition and the outer wall of the calorimetric container. Check whether the thermometer, heater, thermopiles, and the inner screen heating wire are conductive and have insulation performance. The qualified layer uses cotton thread to install the calorimetric tube into the inner screen, and there should be no connection between the two. The wire can be pulled out and the inner screen is closed. 7.6 Install the outer screen
Stick the male group of thermopiles evenly and evenly with the corresponding positions of the inner screen and the inner wall of the outer screen, and check whether the thermopiles and the outer screen heating wires are conductive and have insulation performance. After passing the test, use cotton thread to hang the inner screen on the outer screen. The three should not have any contact. Lead out the wire and close the outer screen. Connect the wire to the host.
7.7 Start-up inspection
SY7517-92
Start the calorimeter and check whether the working status of the signal acquisition, adiabatic control, sample heating, timing and other systems is normal. After passing the test, shut down the machine. Hang the outer screen with cotton thread into the vacuum chamber, seal the vacuum chamber, check the vacuum system and put on the cold bath. 7.8 Lower the temperature of the calorimetric system to below 273K. 8 Instrument calibration
8.1 Empty equivalent determination
8.1.1 Preparation
Number and mark the empty calorimetric container (made according to Sections 7.2 and 7.4). Install the screen, start the inspection and cool down according to Sections 7.5 to 7.
8.1.2 Determination
a. Turn on the vacuum pump to make the system vacuum reach 1.3×10-\Pa. b. Start the heat exchanger, preheat for 30min, and adjust all systems to make them all in good working condition. c. Adjust the experimental temperature rise to 2±0.5K.
d. Adjust the equilibrium time so that the measured humidity change rate is less than 5×10-3K/min. e. The heating interval is 200s and the upper limit of the measured retreat zone is 373K. f. Determine the initial temperature T1 of the first experimental point: collect data once every minute, and collect 10 sets of EV (voltage drop of standard temperature measuring resistor) and E1 (voltage drop of standard platinum resistance thermometer). Calculate the average value and calculate the T1 value using formula (3) in Section 10.1. 9. Determine the added electric energy Q: collect data once every minute, and collect 10 sets of EN (voltage drop of standard energy measuring resistor) and E2 (voltage drop of sample heater voltage divider resistor). Calculate the average value and calculate Q value according to formula (11). h. After the equilibrium period, measure the final temperature, which is the same as f. The final temperature of each measurement point is the initial temperature of the next measurement point, and continue to measure until the upper limit of the measurement temperature range. 8.1.3 Calculation
Calculate the equivalent data of the calorimeter in the temperature range of 273-373K according to the test (12) from the determined series (T1Q, T2), and calculate the comfort value according to formulas (13) to (16) in Section 102. 8.2 Determination of standard substances
8.2.1 Preparation
Weigh the sample, check for leaks, install screens, inspect, and reduce overflow according to Sections 7.3 to 7.8. 8.2.2 Determination
Operate according to Section 8.1
8.2.3 Calculation
Calculate the c value of the standard substance in the temperature range of 273-373K according to formula (3) from the determined series (T1Q, T2). Calculate its comfort value according to formula (13). Parallel experiments are required: the maximum percentage deviation of the comfort value must be less than 0.5%; the maximum percentage deviation of the comfort value and the literature value (Appendix A) must be less than 1 trillion, otherwise find the cause and recalibrate. 8.3 Calibration period of the instrument
Generally, calibration is performed once a year. Any replacement of any component in the adiabatic calorimeter must be recalibrated. 9 Sample determination
9.1 Preparation
Use the calibrated calorimeter and operate according to Sections 7.2 to 7.8. 92 Determination
9.2.1 Repeat the operations from 8.1.2 to d. 9.2.2 The heating time is 600S, and the upper limit of the measurement temperature range is the initial distillation point of the sample being tested (GB255) 9.2.3 Repeat the operations from f to h in 8.1.2. 8.3 Calculate the measured series of [71, Q, T,] data from SY7517-92, and calculate the c value of the tested sample in the temperature range from 273K to the initial boiling point according to formula (3) in Section 10.1. Calculate the comfort value according to formula (13) 10 Calculation formula
10.1 Sample specific heat capacity calculation formula
Wuzhong c—
-the measured value of the specific heat capacity of the sample at temperature, J/(kg·K) Q--the amount of electrical energy added, J,
-the sudden temperature rise, K,
-the average temperature of the experimental point, K,
-the equivalent of the calorimeter at temperature, J/K; m--the mass of the sample, kg.
Temperature calculation formula
AT=T,-T1:
71 = t1 + 273.15-
T, = I2 + 273.15.
ti+ f,
The initial and final temperatures of an experimental point, K,
-The initial and final temperatures of the experimental point, "C. According to the 1990 International Temperature Scale (1TS-90) W(t)= R()
AW()=n[W(t)-+hW(t)-j2
W(t)-W(t) -aW -(t)-
Formula W ()
Standard platinum resistance thermometer resistance ratio:
Standard resistance thermometer resistance at the experimental temperature: Total resistance of the standard platinum resistance thermometer at the water triple point, Q: Temperature measurement standard resistance value, 2;
Standard resistance voltage drop, mV:
Standard platinum resistance thermometer voltage drop at the experimental temperature, mV; Standard platinum resistance thermometer graduation constant! 0 ~ 419.527 ° C temperature range difference function: specific test function.
Output W, (t) value in 0 ~ 961.78 ° C temperature range reference function table, use linear interpolation method to find the corresponding temperature t value, 10.1.2 Electric energy calculation formula
EL) + (R + s +Rss+Ro)Ex
（10)
Wherein: Er——voltage drop of energy measurement standard resistor, V; R1—value of energy measurement standard resistor, 2,
Ex---voltage drop of heater voltage divider resistor, V: SY 7517-92
Ra,Ra value of heater voltage divider resistor, 0
R—lead resistance value, Q;
——heating time,
empty equivalent quantity meter formula
Wherein, H.-empty equivalent quantity of calorimeter at temperature T, J/K; Qo——electric energy added, J,
AT safety test temperature rise, K.
102 Data leveling formula
10.2.1 The attack adopts a multi-factor fitting formula: c
X= (T: B,) /B2*
B, = (T+7.i.) /2******
B2 - (T*x-7i.) /2.......
武：c——Shufu value of specific heat of sample, / (kg·)-set temperature value, K;
T., Tmi. Average temperature of the highest and lowest measuring points in the experiment, K;-polynomial fitting power:
-polynomial coefficient, obtained by the least square method from the measured c, value. 10.2.2 Calculation of data fitting error:
Where:. —Percent standard deviation of the average value, —-number of measured data;
Actual value:
-Shufu value after fitting.
When ra<0.5%, the fitting data is valid. Otherwise, refit, 11 Experimental results show
.100%32
T and c,-T data in the temperature range from 273K to the initial boiling point are reported with a temperature interval of 2K. 12 Precision
The reliability of the determination results shall be determined according to the following provisions (95% confidence level). 12.1 Precision
The difference between two consecutive results determined by the same investigator shall not be greater than 60l(·) 12.2 Reproducibility
The difference between two results obtained by different operators in different laboratories shall not be greater than 105J/(k8·K). -6 --
-(15)
$Y 7517—92
Appendix A
(Supplement)
Literature value of specific heat capacity of standard substance
Zhi Geng Rao
J/(mol.K)
75,280
75,054
Note: (1PTS—68) wet standard is used. i
J/(mal.K)
230,4339
J/cg·K)
$Y 7517—92
Attachment B
(Review)
Example of calculating the specific heat capacity of crude oil from experimental data (calculated according to 6B temperature scale) According to the 1968 Interplanetary Practical Temperature Scale (IPTS—68) t=t'+M (t')
M(t)=0.0456t*
A+VA2+4B (W
Aa(l+
B= - 10-4.α .
Rt =Rn
R. R(0)
Where: α,
Standard platinum resistance thermometer temperature parameters:
Standard platinum resistance thermometer resistance value at 0°C, α; Standard platinum resistance thermometer voltage drop at 1°C, 2mV,
Standard platinum resistance thermometer voltage drop at t\C, mY; ​​Standard temperature voltage drop, 2.
Known: Platinum resistance thermometer parameters:
α = 3,92628 ×10-3
#=1.49748
R(0) -25.7984 0
Temperature measurement standard resistor
Energy measurement standard resistor
Heater voltage-dividing resistor
Lead resistance
Sample weight
Experiment,
When measuring
When measuring Q
When measuring
R=9.99982
Rr1=0.99982
Rk1 = 99.99810
Rr:-1000.019
R。 =2.452
m=0.085309kg
Er2 =10.3619mV
Fr1 = 28.1831mV
EN-0.780060GV
F= f.132032V
7=6003
Fx: =10.3593mY
Frz=28.4324mV
H.=30.58637J/K
Question: The actual riding data of the sample at this time
Solution: (1) Calculate 1
1) ++++++++(B2)
*( B5)
According to T =#1 +273.15
t,=trt+M (t,)
M(fi) -0.645G
1+=.A+VA2+4B (W-1)
SY 7517--92
2-) =3.985 ×10-3,
where: A=α (l+.
B= - 10-48 - r = - 5.8795x10-7Rn_.Ee= 0.9098 ×28.1831-=0.3876.W=
R(0)EN25.7984
Substitute the values ​​of A, B, and I into (3) to obtain t*-13.60, substitute the values ​​into (2) to obtain M(ti)=0.005, substitute the values ​​of t, M(ti) into (1) to obtain, =13.595°c Then
T1 = 273.15 + 13.595 =286-746K（2）Calculate
According to the steps of calculating T1, calculate 12 and get:
T± - 289.2143K
【3）Calculate
TTt+T+= 287.9797K
（4）Calculate7
AT -T -T1=2.4693K
（5）Calculate Q
According to:
（En-Ex
Anz+Rna
1.1320321
=499.3605J
(9.9981+1000.01 +2:4) ×1.132032 ×60099.9081
(6) Calculate G
According to formula (3): C=is-11）／m
Substitute the values ​​of Q△T, H, and m into the above formula
C,=2943.6246J/kg K
Answer: The measured value of the specific heat capacity of the sample at 287.9797K is 2943.6246J／（k, K）. Additional remarks:
This standard was proposed by China National Petroleum Corporation. This standard was drafted by China Petroleum Corporation Pipeline Science Research Institute under the jurisdiction of China National Petroleum Corporation Planning and Design Institute. The drafters of this standard were Chen Jian and Wu Chunfang.
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