A method for testing and calculating the efficiency of a gas turbine waste heat boiler

Abstract

This invention relates to a method for testing and calculating the efficiency of a gas turbine waste heat boiler, comprising the following steps: Step 1, confirming the test before the gas turbine waste heat boiler efficiency test; Step 2, determining the conditions for stable boiler operation; Step 3, calculating the relative molecular mass of natural gas; Step 4, calculating the molar content of C and H elements in the alkene and hydrogen components of natural gas; Step 5, calculating the molar content of non-alkene components in natural gas; Step 6, calculating the amount of dry flue gas Q produced by the complete combustion of natural gas fuel. tgy Calculation; Step 7: Molar quantity of dry air at the gas turbine inlet, Q phgkq And the total dry air molar quantity Q zgkq The calculation includes: Step 8, calculation of the dry air molar ratio in the air; Step 9, calculation of the mass and specific enthalpy of each component of the flue gas; Step 10, calculation of the enthalpy value of the flue gas at the inlet and outlet of the waste heat boiler; Step 11, calculation of the heat dissipation loss and efficiency of the waste heat boiler; This invention reduces the number of test points and improves test efficiency.

Description

Technical Field

[0001] This invention relates to a method for testing and calculating the efficiency of a gas turbine waste heat boiler, belonging to the technical field of performance evaluation of gas turbine waste heat boilers. Background Technology

[0002] Currently, most large-scale gas turbines in China are imported units. Performance testing of gas-fired combined cycle units is mostly conducted according to ASME standards, including ASME PTC46-1996 "Integrated Performance Testing Standards for Power Plants," ASME PTC22-2005 "Gas Turbine Performance Testing Procedures," and ASME PTC4.4-2008 "Gas Turbine Waste Heat Boiler Performance Testing Procedures." The waste heat boiler efficiency test follows ASME PTC4.4-2008. There is also a corresponding domestic industry standard, DL / T1427-2015 "Combined Cycle Waste Heat Boiler Performance Testing Procedures," whose content is similar to ASME standards. PTC4.4-2008, "Performance Test Procedure for Waste Heat Boilers from Gas Turbines," is essentially the same, except that some parameters in the measurement and calculation are replaced with SI units for imperial units. The test content and methods are identical in both standards, requiring the measurement and calculation of the enthalpy increase of the working fluid extracting heat from the waste heat boiler based on heat balance. A typical gas turbine waste heat boiler system includes high-pressure steam, medium-pressure steam, low-pressure steam, and performance heater systems, etc. Therefore, the enthalpy increase of the working fluid requires testing and calculating multiple feedwater flow rates, working fluid pressures, and temperatures. The steam-water system is complex to manage, the installation and measurement of measuring points are arduous, and the calculation of the enthalpy increase of the working fluid is tedious. Summary of the Invention

[0003] This invention provides a method for testing and calculating the efficiency of a gas turbine waste heat boiler that can be displayed in real time in a distributed control system for waste heat boilers in a combined cycle gas turbine unit.

[0004] The present invention adopts the following technical solution:

[0005] The present invention provides a method for testing and calculating the efficiency of a gas turbine waste heat boiler, comprising the following steps:

[0006] Step 1: Before testing the efficiency of the gas turbine waste heat boiler, confirm the testing of natural gas side parameters, dry air molar content, gas turbine exhaust diffuser temperature measurement, and flue gas parameter testing of the chimney SEMS platform.

[0007] Step 2: Determine the conditions for stable boiler operation;

[0008] Step 3: Calculation of the relative molecular mass of natural gas;

[0009] Step 4: Calculation of the molar content of C and H elements in the alkane and hydrogen components of natural gas;

[0010] Step 5: Calculation of the molar content of non-alkane components in natural gas;

[0011] Step 6: The amount of dry flue gas Q produced by the complete combustion of natural gas fuel tgy Calculation;

[0012] Step 7: Molar quantity Q of dry air at the gas turbine inlet phgkq And the total dry air molar quantity Q zgkq Calculation;

[0013] Step 8: Calculation of the dry air molar ratio in the air;

[0014] Step 9: Calculation of the mass and specific enthalpy of each component of the flue gas;

[0015] Step 10: Calculation of enthalpy values ​​of flue gas at the inlet and outlet of the waste heat boiler;

[0016] Step 11: Calculation of heat loss and efficiency of waste heat boiler.

[0017] The method for testing and calculating the efficiency of a gas turbine waste heat boiler in this invention includes the following formula for calculating the relative molecular mass of natural gas in step three:

[0018] TRQ=(∑a i a i ) / 100 (1)

[0019] Where: TRQ—relative molecular mass of natural gas; unit: g / mol

[0020] a i —Molar percentage of each component of natural gas; unit: %

[0021] a i —Relative molecular mass of each component of natural gas; unit: g / mol.

[0022] The method for testing and calculating the efficiency of a gas turbine waste heat boiler in this invention includes the following formula for calculating the molar content of element C in step four:

[0023] C mol =∑QxC x H y / TRQ (2) The formula for calculating the molar content of H element is:

[0024] H mol =∑QyC x H y / TRQ (3)

[0025] In equations (2) and (3):

[0026] Q—Mass flow rate of natural gas; unit: kg / h;

[0027] C mol —The total C molar content of alkanes (including hydrogen) in natural gas; unit: mol / h;

[0028] H mol —The total hydrogen molar content of alkanes (including hydrogen) in natural gas; unit: mol / h;

[0029] C x H y —Molar ratio of alkanes (containing hydrogen) in natural gas; unit: % (mol / mol).

[0030] The present invention relates to a method for testing and calculating the efficiency of a gas turbine waste heat boiler. In step five, the non-alkene components include nitrogen (N2), carbon dioxide (CO2), helium (He), and water (H2O). The calculation formulas for the molar contents of nitrogen (N2), carbon dioxide (CO2), helium (He), and water (H2O) are as follows:

[0031] N 2(mol) =QN2 / TRQ (4)

[0032] CO 2(mol) =QCO2 / TRQ (5)

[0033] He (mol) =QHe / TRQ (6)

[0034] H2O (mol) =QH2O / TRQ (7)

[0035] BH2O (mol) =N 2(mol) +CO 2(mol) +He (mol (8)

[0036] in:

[0037] BH2O (mol — Total molar amount of components other than water vapor; unit: mol / h.

[0038] The present invention relates to a method for testing and calculating the efficiency of a gas turbine waste heat boiler, wherein in step six, the amount of dry flue gas Q generated by the complete combustion of natural gas fuel is... tgy The calculation formula is:

[0039]

[0040] In the formula: C gy(mol)—The molar amount of dry flue gas produced by the complete combustion of carbon in natural gas;

[0041] Unit: mol / h;

[0042]

[0043] In the formula: H gy(mol) —Molar amount of dry flue gas produced by the complete combustion of hydrogen in natural gas; unit: mol / h;

[0044] Q tgy =C gy(mol) +H gy(mol) +BH2O (mol) -O 2(mol) / (O2) (11)

[0045] In the formula: Q tgy -------Molar amount of dry flue gas produced by the complete combustion of natural gas; unit: mol / h.

[0046] The present invention relates to a method for testing and calculating the efficiency of a gas turbine waste heat boiler. In step seven, the molar amount of dry air at the gas turbine inlet is Q. phgkq The calculation formula is:

[0047] Q phgkq =Q tgy ×O 2c / ((O2)-O 2c (12)

[0048] In the formula: O 2c —Measurement of oxygen content in dry flue gas at the chimney as a mole percentage; unit: % (mol);

[0049] Total dry air molar quantity Q at the gas turbine inlet zgkq The calculation formula is:

[0050]

[0051] Q zgkq =C gk(mol) +H gk(mol) +Q phgkq -O 2(mol) / (O2) (15)

[0052] In the formula: C gk(mol) —The amount of dry air required for the complete combustion of carbon in natural gas;

[0053] Unit: mol / h;

[0054] H gk(mol) --- The amount of dry air required for the complete combustion of hydrogen in natural gas;

[0055] Unit: mol / h;

[0056] Q zgkq —Total dry air molar quantity at the gas turbine inlet; unit: mol / h.

[0057] The method for testing and calculating the efficiency of a gas turbine waste heat boiler in this invention, specifically the calculation method for the dry air molar ratio in step eight, is as follows:

[0058] According to the ambient temperature T h 'Looking up the table of saturated water vapor partial pressures, the saturated partial pressure of water vapor is Pv;

[0059] Or it can be calculated using the formula:

[0060] T h =1.8(T) h '+273.15) (16)

[0061] When -100℃ to 0℃

[0062] Pv = 6894.757 EXP

[0063] (-1.0214165E4 / T h -4.8932428-5.3765794E-3T h -1.9202377E-7T h 2 -3.5575832E-10T h 3 -9.0344688E-14T h 4 +4.1635019ln(T h );

[0064] When the temperature is between 0℃ and 200℃

[0065] Pv = 6894.757 EXP

[0066] (-1.0440397E4 / T h -11.294650-2.7022355E-2T h +1.2890360E-5T h 2 -2.4780681E-9T h 3 +6.5459673ln(T h );

[0067]

[0068] In the formula:

[0069] T h '—Ambient temperature; Unit: °C;'

[0070] T h —Ambient temperature (Rankine temperature); Unit: R;

[0071] R—Relative humidity; Unit: %;

[0072] Pv—Partial pressure of saturated water vapor; Unit: Pa;

[0073] P atm —Local atmospheric pressure; Unit: Pa;

[0074] —Partial pressure of water vapor in the air; unit: Pa;

[0075] G mb ----Molar ratio of dry air to air; unit: %.

[0076] The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to the present invention, wherein the formula for calculating the mass of each component of the flue gas in step nine is as follows:

[0077]

[0078] In the formula: ----Nitrogen content in flue gas, unit: g / h;

[0079]

[0080] In the formula: ----Oxygen content in flue gas, unit: g / h;

[0081]

[0082] In the formula: ----Carbon dioxide content in flue gas, unit: g / h;

[0083] Z Ar =(Q zgkq ×(Ar))×Ar' (22)

[0084] In the formula: Z Ar Argon content in flue gas, unit: g / h;

[0085]

[0086] In the formula: -----Water vapor content in flue gas, unit: g / h;

[0087] The formula for calculating the specific enthalpy of each component of the flue gas is as follows:

[0088] h i =2.326(-A1 / T+A2 ln(T)+A3T+A4T 2 +A5T 3 +A6T 4 +A7T 5 -A8)(24)

[0089] In the formula: hi----enthalpy value of each component of flue gas, unit: g / h;

[0090] T----Flue gas temperature, unit: Land scale °R, °R = 1.8 (℃ + 273.15),

[0091] The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to the present invention includes the following formula for calculating the enthalpy of the flue gas at the inlet and outlet of the waste heat boiler in step ten:

[0092]

[0093] In the formula: H r -----Heat of flue gas at the inlet of the waste heat boiler, unit: J / h;

[0094]

[0095] Where: H c -----Heat of flue gas at the outlet of the waste heat boiler, unit: J / h.

[0096] The method for testing and calculating the efficiency of a gas turbine waste heat boiler in this invention includes the following formula for calculating heat loss of the waste heat boiler in step eleven:

[0097]

[0098] In the formula: q rs ----- Waste heat boiler heat loss, unit: J / h;

[0099] The efficiency calculation formula for a waste heat boiler is as follows:

[0100] η=(H r -H c -q rs )×100 / H r unit:%.

[0101] The positive effects of this invention are as follows: First, it eliminates the need for measuring pressure, temperature, flow rate, and other parameters on the boiler steam and water sides, reducing the workload and improving efficiency. Second, based on the DCS panel parameters, this invention enables real-time online display of waste heat boiler efficiency, providing operators with a basis for adjusting boiler parameters. Third, the invention requires significantly less on-site measurement data than the original method, reducing the uncertainty of test results and improving test accuracy. Attached Figure Description

[0102] Appendix Figure 1 This is a schematic diagram showing the location of the measuring points for testing the efficiency of a waste heat boiler. Detailed Implementation

[0103] The present invention provides a method for testing and calculating the efficiency of a gas turbine waste heat boiler, comprising the following steps:

[0104] Step 1: Before testing the efficiency of the gas turbine waste heat boiler, confirm the testing of natural gas side parameters, dry air molar content, gas turbine exhaust diffuser temperature measurement, and flue gas parameter testing of the chimney SEMS platform.

[0105] Step 2: Determine the conditions for stable boiler operation;

[0106] Step 3: Calculation of the relative molecular mass of natural gas;

[0107] Step 4: Calculation of the molar content of C and H elements in the alkane and hydrogen components of natural gas;

[0108] Step 5: Calculation of the molar content of non-alkane components in natural gas;

[0109] Step 6: The amount of dry flue gas Q produced by the complete combustion of natural gas fuel tgy Calculation;

[0110] Step 7: Molar quantity Q of dry air at the gas turbine inlet phgkq And the total dry air molar quantity Q zgkq Calculation;

[0111] Step 8: Calculation of the dry air molar ratio in the air;

[0112] Step 9: Calculation of the mass and specific enthalpy of each component of the flue gas;

[0113] Step 10: Calculate the enthalpy of flue gas at the inlet and outlet of the waste heat boiler; Step 11: Calculate the heat dissipation loss and efficiency of the waste heat boiler.

[0114] The method for testing and calculating the efficiency of a gas turbine waste heat boiler in this invention includes the following formula for calculating the relative molecular mass of natural gas in step three:

[0115] TRQ=(∑a i ai ) / 100 (1)

[0116] Where: TRQ—relative molecular mass of natural gas; unit: g / mol

[0117] a i —Molar percentage of each component of natural gas; unit: %

[0118] a i —Relative molecular mass of each component of natural gas; unit: g / mol.

[0119] The method for testing and calculating the efficiency of a gas turbine waste heat boiler in this invention includes the following formula for calculating the molar content of element C in step four:

[0120] C mol =∑QxC x H y / TRQ (2) The formula for calculating the molar content of H element is:

[0121] H mol =∑QyC x H y / TRQ (3)

[0122] In equations (2) and (3):

[0123] Q—Mass flow rate of natural gas; unit: kg / h;

[0124] C mol —The total C molar content of alkanes (including hydrogen) in natural gas; unit: mol / h;

[0125] H mol —The total hydrogen molar content of alkanes (including hydrogen) in natural gas; unit: mol / h;

[0126] C x H y —Molar ratio of alkanes (containing hydrogen) in natural gas; unit: % (mol / mol).

[0127] The present invention relates to a method for testing and calculating the efficiency of a gas turbine waste heat boiler. In step five, the non-alkene components include nitrogen (N2), carbon dioxide (CO2), helium (He), and water (H2O). The calculation formulas for the molar contents of nitrogen (N2), carbon dioxide (CO2), helium (He), and water (H2O) are as follows:

[0128] N 2(mol) =QN2 / TRQ (4)

[0129] CO 2(mol)=QCO2 / TRQ (5)

[0130] He (mol) =QHe / TRQ (6)

[0131] H2O (mol) =QH2O / TRQ (7)

[0132] BH2O (mol) =N 2(mol) +CO 2(mol) +He (mol) (8)

[0133] in:

[0134] BH2O (mol) —Total molar amount of components other than water vapor; unit: mol / h.

[0135] The present invention relates to a method for testing and calculating the efficiency of a gas turbine waste heat boiler, wherein in step six, the amount of dry flue gas Q generated by the complete combustion of natural gas fuel is... tgy The calculation formula is:

[0136]

[0137] In the formula: C gy(mol) —The molar amount of dry flue gas produced by the complete combustion of carbon in natural gas;

[0138] Unit: mol / h;

[0139]

[0140] In the formula: H gy(mol) —Molar amount of dry flue gas produced by the complete combustion of hydrogen in natural gas; unit: mol / h;

[0141] Q tgy =C gy(mol) +H gy(mol) +BH2O (mol) -O 2(mol) / (O2) (11)

[0142] In the formula: Q tgy -------Molar amount of dry flue gas produced by the complete combustion of natural gas; unit: mol / h.

[0143] The present invention relates to a method for testing and calculating the efficiency of a gas turbine waste heat boiler. In step seven, the molar amount of dry air at the gas turbine inlet is Q. phgkq The calculation formula is:

[0144] Q phgkq =Q tgy ×O 2c / ((O2)-O 2c (12)

[0145] In the formula: O 2c —Measurement of oxygen content in dry flue gas at the chimney as a mole percentage; unit: % (mol);

[0146] Total dry air molar quantity Q at the gas turbine inlet zgkq The calculation formula is:

[0147]

[0148] Q zgkq =C gk(mol) +H gk(mol) +Q phgkq -O 2(mol) / (O2) (15)

[0149] In the formula: C gk(mol) —The amount of dry air required for the complete combustion of carbon in natural gas;

[0150] Unit: mol / h;

[0151] H gk(mol) --- The amount of dry air required for the complete combustion of hydrogen in natural gas;

[0152] Unit: mol / h;

[0153] Q zgkq —Total dry air molar quantity at the gas turbine inlet; unit: mol / h.

[0154] The method for testing and calculating the efficiency of a gas turbine waste heat boiler in this invention, specifically the calculation method for the dry air molar ratio in step eight, is as follows:

[0155] According to the ambient temperature T h 'Looking up the table of saturated water vapor partial pressures, the saturated partial pressure of water vapor is Pv;

[0156] Or it can be calculated using the formula:

[0157] T h =1.8(T) h '+273.15) (16)

[0158] When -100℃ to 0℃

[0159] Pv = 6894.757 EXP

[0160] (-1.0214165E4 / T h -4.8932428-5.3765794E-3T h -1.9202377E-7Th 2 -3.5575832E-10T h 3 -9.0344688E-14T h 4 +4.1635019ln(T h );

[0161] When the temperature is between 0℃ and 200℃

[0162] Pv = 6894.757 EXP

[0163] (-1.0440397E4 / T h -11.294650-2.7022355E-2T h +1.2890360E-5T h 2 -2.4780681E-9T h 3 +6.5459673ln(T h );

[0164]

[0165] In the formula:

[0166] T h '—Ambient temperature; Unit: °C;'

[0167] T h —Ambient temperature (Rankine temperature); Unit: R;

[0168] R—Relative humidity; Unit: %;

[0169] Pv—Partial pressure of saturated water vapor; Unit: Pa;

[0170] P atm —Local atmospheric pressure; Unit: Pa;

[0171] —Partial pressure of water vapor in the air; unit: Pa;

[0172] G mb ----Molar ratio of dry air to air; unit: %.

[0173] The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to the present invention, wherein the formula for calculating the mass of each component of the flue gas in step nine is as follows:

[0174]

[0175] In the formula: ----Nitrogen content in flue gas, unit: g / h;

[0176]

[0177] In the formula: ----Oxygen content in flue gas, unit: g / h;

[0178]

[0179] In the formula: ----Carbon dioxide content in flue gas, unit: g / h;

[0180]

[0181] In the formula: Z Ar Argon content in flue gas, unit: g / h;

[0182]

[0183] In the formula: -----Water vapor content in flue gas, unit: g / h;

[0184] The formula for calculating the specific enthalpy of each component of the flue gas is as follows:

[0185] h i =2.326(-A1 / T+A2 ln(T)+A3T+A4T 2 +A5T 3 +A6T 4 +A7T 5 -A8)(24)

[0186] In the formula: hi----enthalpy value of each component of flue gas, unit: g / h;

[0187] T----Flue gas temperature, unit: Land scale °R, °R = 1.8 (℃ + 273.15),

[0188] The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to the present invention includes the following formula for calculating the enthalpy of the flue gas at the inlet and outlet of the waste heat boiler in step ten:

[0189]

[0190] In the formula: H r -----Heat of flue gas at the inlet of the waste heat boiler, unit: J / h;

[0191]

[0192] In the formula: H c -----Heat of flue gas at the outlet of the waste heat boiler, unit: J / h.

[0193] The method for testing and calculating the efficiency of a gas turbine waste heat boiler in this invention includes the following formula for calculating heat loss of the waste heat boiler in step eleven:

[0194]

[0195] In the formula: q rs ----- Waste heat boiler heat loss, unit: J / h;

[0196] The efficiency calculation formula for a waste heat boiler is as follows:

[0197] unit:%.

[0198] As attached Figure 1 As shown, this invention takes the testing and calculation method of the waste heat boiler efficiency of a type F gas turbine in a thermal power company of Hebei Southern Power Grid as an example, and adopts the following steps:

[0199] Step 1: Confirm the following before testing the efficiency of the gas turbine waste heat boiler:

[0200] 1. Natural gas side parameter testing: Natural gas composition analysis typically uses data from the power plant's online chromatographic analyzer, which is accurate and reliable; natural gas flow rate data is obtained from the power plant's online instrumentation.

[0201] 2. Dry air molar content test: At the gas turbine air inlet platform, measure atmospheric pressure, ambient dry bulb temperature and relative humidity at multiple points;

[0202] 3. Flue gas temperature measurement at the inlet of the waste heat boiler, i.e., the exhaust diffusion section of the gas turbine: Gas turbine manufacturers usually arrange 6 or more measuring devices evenly around the circumference at this point. During the calibration period, the average value of the flue gas temperature data from multiple points on the DCS can be used for the measuring elements.

[0203] 4. Flue Gas Parameter Testing on the SEMS Platform for Chimneys: The oxygen content and temperature of the flue gas were measured using the grid method. Since the waste heat boiler operates under positive pressure, air cannot leak into the flue gas. Therefore, the flue gas composition at the chimney of the waste heat boiler is the same as that at the inlet of the waste heat boiler. After thorough mixing through the waste heat boiler process, the flue gas composition at the chimney is very uniform. The online test data of flue gas content at a single point on the SEMS can be used as the average value of the multi-point test values ​​of the cross-section. Due to the different heat exchange of the tail heating surface and the short flue gas mixing distance, the flue gas temperature needs to be measured using the multi-point grid method.

[0204] Step 2: The flue gas temperature at the outlet of the waste heat boiler is stable, the curve is flat, and the temperature fluctuation is within 0.5℃. The atmospheric pressure is 100.5 kPa, the ambient temperature is 16.3℃, the relative humidity is 63%, the flue gas temperature at the inlet of the waste heat boiler is 586.7℃, the flue gas temperature at the outlet of the waste heat boiler is 96℃, the oxygen content of the flue gas at the outlet of the waste heat boiler is 13.8%, the natural gas flow rate is 15.55 kg / s, and the molar ratio of the natural gas composition is shown in Table 1. Begin data measurement and recording.

[0205] Step 3: The formula for calculating the relative molecular mass of natural gas is as follows:

[0206] TRQ=(∑a i a i ) / 100 (1)

[0207] In the formula: TRQ—relative molecular mass of natural gas; unit: g / mol;

[0208] a i —Molar percentage of each component of natural gas; unit: %;

[0209] a i —Relative molecular mass of each component of natural gas; unit: g / mol;

[0210] The specific calculated values ​​based on the above formula are shown in Table 1 below:

[0211]

[0212] Table 1

[0213] Step 4: Calculate the molar content of C and H elements in the alkane and hydrogen components of natural gas. The formula for calculating the molar content of C element is as follows:

[0214] C mol =∑QxC x H y / TRQ (2) The formula for calculating the molar content of H element is:

[0215] H mol =∑QyC x H y / TRQ (3)

[0216] In equations (2) and (3):

[0217] Q—Mass flow rate of natural gas; unit: kg / h;

[0218] C mol —The total C molar content of alkanes (including hydrogen) in natural gas; unit: mol / h;

[0219] H mol —The total hydrogen molar content of alkanes (including hydrogen) in natural gas; unit: mol / h;

[0220] C x H y —Molar ratio of alkanes (containing hydrogen) in natural gas; Unit: % (mol / mol);

[0221] The specific calculated values ​​based on the above formula are shown in Table 2 below:

[0222]

[0223] Table 2

[0224] Step 5: Calculation of the molar content of non-alkane components in natural gas; Non-alkane components include nitrogen (N2), carbon dioxide (CO2), helium (He), and water (H2O). The formulas for calculating the molar content of nitrogen (N2), carbon dioxide (CO2), helium (He), and water (H2O) are as follows:

[0225] N 2(mol) =QN2 / TRQ (4)

[0226] CO 2(mol) =QCO2 / TRQ (5)

[0227] He (mol) =QHe / TRQ (6)

[0228] H2O (mol) =QH2O / TRQ (7)

[0229] BH2O (mol) =N 2(mol) +CO 2(mol) +He (mol) (8)

[0230] in:

[0231] BH2O (mol) —Total molar amount of components other than water vapor; unit: mol / h;

[0232] The specific calculated values ​​based on the above formula are shown in Table 3 below:

[0233]

[0234] Table 3

[0235] Step 6: The amount of dry flue gas Q produced by the complete combustion of natural gas fuel tgy Calculation:

[0236]

[0237] Q tgy =C gy(mol) +H gy(mol) +BH2O (mol) =28,819,386.92 units: mol / h;

[0238] Step 7: Molar quantity Q of dry air at the gas turbine inlet phgkq The calculation is as follows:

[0239] Q phgkq =Q tgy ×O 2c / ((O2)-O 2c )

[0240] =28819386.92*0.138 / (0.209476-0.138) = 55642109.18

[0241] Unit: mol / h;

[0242] In the formula: O 2c —Measurement of oxygen content in dry flue gas at the chimney as a mole percentage; unit: % (mol);

[0243] Total dry air molar quantity Q at the gas turbine inlet zgkq The calculation formula is:

[0244]

[0245] Q zgkq =C gk(mol) +H gk(mol) +Q phgkq =87721307.17 Unit: mol / h Where:

[0246] C gk(mol) —The amount of dry air required for the complete combustion of carbon in natural gas; unit: mol / h;

[0247] H gk(mol) —The amount of dry air required for the complete combustion of H in natural gas; unit: mol / h; Q zgkq —Total dry air molar quantity at the gas turbine inlet; unit: mol / h.

[0248] Step 8: The calculation of the dry air molar ratio in the air is as follows:

[0249] According to the ambient temperature T h 'Looking up the table of saturated water vapor partial pressures, the saturated partial pressure of water vapor is Pv;

[0250] Or it can be calculated using the formula:

[0251] T h =1.8(T) h (+273.15)

[0252] When -100℃ to 0℃

[0253] Pv = 6894.757 EXP

[0254] (-1.0214165E4 / T h -4.8932428-5.3765794E-3T h -1.9202377E-7T h 2 -3.5575832E-10T h 3 -9.0344688E-14T h 4 +4.1635019ln(T h );

[0255] When the temperature is between 0℃ and 200℃

[0256] Pv = 6894.757 EXP

[0257] (-1.0440397E4 / T h -11.294650-2.7022355E-2T h +1.2890360E-5T h 2 -2.4780681E-9T h 3 +6.5459673ln(T h = 6894.757 * 0.268841 = 1852.336175 (Unit: Pa)

[0258] P H2O =RPv=0.63*1852.336175=1166.97179 Unit: Pa

[0259] G mb =(P atm -P H2O ) / P atm =(100550-1166.97179) / 100550=0.98838624%(mol)

[0260] In the formula:

[0261] T h '—Ambient temperature; Unit: °C;'

[0262] T h —Ambient temperature (Rankine temperature); Unit: R;

[0263] R—Relative humidity; Unit: %;

[0264] Pv—Partial pressure of saturated water vapor; Unit: Pa;

[0265] P atm —Local atmospheric pressure; Unit: Pa;

[0266] —Partial pressure of water vapor in the air; unit: Pa;

[0267] G mb ----Molar ratio of dry air to air; unit: %.

[0268] Step 9: Calculation of the mass and specific enthalpy of each gas component in the flue gas.

[0269] The mass calculation of each component in the flue gas is as follows:

[0270]

[0271] Calculation of specific enthalpy of each component in flue gas:

[0272] h i =2.326(-A1 / T+A2 ln(T)+A3T+A4T 2 +A5T 3 +A6T 4 +A7T 5 -A8)(24)

[0273] In the formula: hi----enthalpy value of each component of flue gas, unit: g / h;

[0274] T----Flue gas temperature, unit: Landau scale °R, °R=1.8(℃+273.15). Selection of the coefficient when T≤724.85℃:

[0275] <![CDATA[A1]]> <![CDATA[A2]]> <![CDATA[A3]]> <![CDATA[A4]]> <![CDATA[A5]]> <![CDATA[A6]]> <![CDATA[A7]]> <![CDATA[A8]]> <![CDATA[N2]]> 5.076903444E3 -4.872474552E1 4.31208942E-1 -1.679893331E-4 1.00986003E-7 -2.92514667E-11 3.403129176E-15 -1.235670205E2 <![CDATA[O2]]> -6.888073538E3 5.414599817E1 6.9447256E-2 7.402341031E-5 -4.364913417E-9 -5.382934954E-12 1.22855047E-15 4.069617332E2 <![CDATA[CO2]]> 7.227711078E3 -5.087920389E1 2.39235281E-1 3.138394549E-5 -9.87579956E-10 -1.48749738E-12 2.449873977E-16 -1.9950475E2 <![CDATA[H2O]]> -1.410039482E4 1.142053432E2 1.02713623E-1 2.211623913E-4 -8.327114025E-8 2.34141933E-11 -2.807780325E-15 8.443000544E2 Ar 0 0 1.24279476E-1 0 0 0 0 6.458431507E1 <![CDATA[SO2]]> -5.333964877E3 5.072160967E1 -7.3060273E-2 1.898189113E-4 -8.007268636E-8 1.92186454E-11 -1.989719608E-15 3.308196608E2

[0276] Table 4. Selection of coefficients when T ≥ 724.85℃:

[0277] <![CDATA[A1]]> <![CDATA[A2]]> <![CDATA[A3]]> <![CDATA[A4]]> <![CDATA[A5]]> <![CDATA[A6]]> <![CDATA[A7]]> <![CDATA[A8]]> <![CDATA[N2]]> 1.349890343E5 -2.857350578E2 4.3008964E-1 -1.209016552E-5 1.088015054E-9 -5.844054022E-14 1.434281709E-18 -1.8095882177E3 <![CDATA[O2]]> -2.087072821E5 -2.619417179E2 1.12934906E-1 2.185673559E-5 -1.397060777E-9 5.463669086E-14 -9.687873053E-19 2.037040157E3 <![CDATA[CO2]]> 1.720741433E4 -1.452915082E2 3.74147054E-1 -1.15607258E-6 2.2579091E-11 -3.65792361E-15 5.44194572E-19 -7.584598037E2 <![CDATA[H2O]]> 3.696469091E5 -4.787281864E2 5.12156854E-1 7.018191588E-5 -7.753574698E-9 4.454356391E-13 -1.01277945E-17 -3.313267173E3 Ar 3.238297928 -5.362306E-3 1.24282926E-1 -5.51268E-10 6.16422E-14 -3.87631E-18 1.021528E-22 6.454706733E1 <![CDATA[SO2]]> -1.132549719E4 -4.604550381E1 2.36090695E-1 -1.72156415E-6 1.80366793E-10 -7.24777306E-15 1.723497991E-19 -1.514826348E2

[0278] Table 5 shows the specific calculated values ​​of the specific enthalpy of each component of the flue gas based on the above formula, as shown in Table 6 below:

[0279] Natural gas composition Enthalpy of components at inlet smoke temperature Enthalpy values ​​of components at the outlet flue gas temperature <![CDATA[N2]]> 614.5024317 83.70124246 <![CDATA[O2]]> 567.106796 74.33083064 <![CDATA[CO2]]> 596.8046232 70.33187408 <![CDATA[H2O]]> 1146.828567 150.744552 Ar 297.1854837 41.85697338

[0280] Table 6, Step 10: Calculation of enthalpy values ​​of flue gas at the inlet and outlet of the waste heat boiler:

[0281]

[0282] Step 11: Calculation of heat loss from the waste heat boiler:

[0283]

[0284] Efficiency calculation of waste heat boiler:

[0285] η=(H r -H c -q rs )×100 / H r =(1.65009E+12-2.21288E+11-3937305509)*100 / 1.65009E+12=86.35 units:%.

[0286] The method of this invention offers several advantages: First, it eliminates the need for measuring pressure, temperature, flow rate, and other parameters on the boiler's steam and water sides, reducing the workload and improving efficiency. Second, based on DCS panel parameters, this invention enables real-time online display of waste heat boiler efficiency, providing operators with a basis for adjusting boiler parameters. Third, the invention significantly reduces the amount of on-site measurement data required compared to the original method, thereby lowering the uncertainty of test results and improving test accuracy.

[0287] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for testing and calculating the efficiency of a gas turbine waste heat boiler, characterized in that... Includes the following steps: Step 1: Before testing the efficiency of the gas turbine waste heat boiler, confirm the testing of natural gas side parameters, dry air molar content, gas turbine exhaust diffuser temperature, and flue gas parameters on the SEMS platform of the chimney; Step 2: Determine the conditions for stable boiler operation; Step 3: Calculate the relative molecular mass of natural gas; Step 4: Calculate the molar content of C and H elements in the alkene and hydrogen components of natural gas; Step 5: Calculate the molar content of non-alkene components in natural gas; Step 6: Calculate the amount of dry flue gas Q produced by the complete combustion of natural gas fuel. tgy Calculation; Step 7: Molar quantity of dry air at the gas turbine inlet, Q phgkq And the total dry air molar quantity Q zgkq The calculations are as follows: Step 8: Calculation of the dry air molar ratio in the air; Step 9: Calculation of the mass and specific enthalpy of each component of the flue gas; Step 10: Calculation of the heat of the flue gas at the inlet and outlet of the waste heat boiler; Step 11: Calculation of the heat loss and efficiency of the waste heat boiler. The formulas for calculating the mass and specific enthalpy of each component of the flue gas in step nine are as follows: In the formula: ----Nitrogen content in flue gas, unit: g / h; N 2(mol) ----Nitrogen molar content in natural gas; In the formula: ----Oxygen content in flue gas, unit: g / h; C mol —The C molar content of the total amount of alkanes and alkenes in natural gas; In the formula: ----Carbon dioxide content in flue gas, unit: g / h; CO 2(mol) ----Molar content of carbon dioxide in natural gas; Z Ar =(Q zgkq ×(Ar))×Ar' (22) In the formula: Z Ar Argon content in flue gas, unit: g / h; The formula for calculating the specific enthalpy of each component of the flue gas is as follows: h i =2.326(-A1 / T+A2ln(T)+A3T+A4T 2 +A5T 3 +A6T 4 +A7T 5 -A8)(24) Where: hi----enthalpy value of each component of flue gas, unit: g / h; T---- Flue gas temperature, unit: Land scale °R, °R=1.8(℃+273.15).

2. The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to claim 1, characterized in that... The formula for calculating the relative molecular mass of natural gas in step three is as follows: TRQ=(∑a i a i ) / 100 (1) Where: TRQ—relative molecular mass of natural gas; unit: g / mol a i —Molar percentage of each component of natural gas; unit: % a i —Relative molecular mass of each component of natural gas; unit: g / mol.

3. The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to claim 2, characterized in that... The formula for calculating the molar content of element C in step four is as follows: C mol =∑QxC x H y / TRQ (2) The formula for calculating the molar content of H element is: H mol =∑QyC x H y / TRQ (3) In equations (2) and (3): Q—Mass flow rate of natural gas; unit: kg / h; C mol —The total C molar content of alkanes and alkenes in natural gas; unit: mol / h; H mol —The total H molar content of alkanes and alkenes in natural gas; unit: mol / h; C x H y —Molar ratio of alkanes and alkenes in natural gas; unit: % (mol / mol).

4. The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to claim 1, characterized in that... In step five, the non-alkene components include nitrogen (N2), carbon dioxide (CO2), helium (He), and water (H2O). The formulas for calculating the molar content of nitrogen (N2), carbon dioxide (CO2), helium (He), and water (H2O) are as follows: N 2(mol) =QN2 / TRQ (4) CO 2(mol) =QCO2 / TRQ (5) He (mol) =QHe / TRQ (6) H2O (mol) =QH2O / TRQ (7) BH2O (mol) =N 2(mol) +CO 2(mol) +He (m ol) (8) in: BH2O (mol) —Total molar amount of components other than water vapor; unit: mol / h.

5. The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to claim 1, characterized in that... The amount of dry flue gas Q produced by the complete combustion of natural gas in step six tgy The calculation formula is: In the formula: C gy(mol) —The molar amount of dry flue gas produced by the complete combustion of carbon in natural gas; Unit: mol / h; In the formula: H gy(mol) —The molar amount of dry flue gas produced by the complete combustion of hydrogen in natural gas; Unit: mol / h; Q tgy =C gy(mol) +H gy(mol) +BH2O (mol) (11) In the formula: Q tgy -------Molar amount of dry flue gas produced by the complete combustion of natural gas; Unit: mol / h.

6. The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to claim 1, characterized in that... In step seven, the molar amount of dry air at the gas turbine inlet is Q. phgkq The calculation formula is: Q phgkq =Q tgy ×O 2c / ((O2)-O 2c ) (12) In the formula: O 2c —Measurement of oxygen content in dry flue gas at the chimney as a mole percentage; unit: % (mol); Total dry air molar quantity Q at the gas turbine inlet zgkq The calculation formula is: Q zgkq =C gk(mol) +H gk(mol) +Q phgkq (15) In the formula: C gk(mol) —The amount of dry air required for the complete combustion of carbon in natural gas; Unit: mol / h; H gk(mol) --- The amount of dry air required for the complete combustion of hydrogen in natural gas; unit: mol / h; Q zgkq —Total dry air molar quantity at the gas turbine inlet; Unit: mol / h.

7. The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to claim 1, characterized in that... The calculation method for the dry air molar ratio in step eight is as follows: According to the ambient temperature T h 'Looking up the table of saturated water vapor partial pressures, the saturated partial pressure of water vapor is Pv; Or it can be calculated using the formula: T h =1.8(T h ’+273.15) (16) When -100℃ to 0℃ Pv=6894.757EXP(-1.0214165E4 / T h -4.8932428-5.3765794E-3T h -1.9202377E-7T h 2 -3.5575832E-10T h 3 -9.0344688E-14T h 4 +4.1635019ln(T h ); When the temperature is between 0℃ and 200℃ Pv=6894.757EXP(-1.0440397E4 / T h -11.294650-2.7022355E-2T h +1.2890360E-5T h 2 -2.4780681E-9T h 3 +6.5459673ln(T h ); G mb =(P atm - P H2O ) / P atm (18) In the formula: T h '—Ambient temperature; Unit: °C;' T h —Ambient temperature; unit: R; R—Relative humidity; Unit: %; Pv — Saturated water vapor partial pressure; unit: Pa; P atm —Local atmospheric pressure; Unit: Pa; —Partial pressure of water vapor in the air; Unit: Pa; G mb ----Molar ratio of dry air to air; unit: %.

8. The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to claim 1, characterized in that... The formula for calculating the heat of the flue gas at the inlet and outlet of the waste heat boiler in step ten is as follows: Where: H r -----Heat of flue gas at the inlet of the waste heat boiler, unit: J / h; In the formula: H c -----Heat of flue gas at the outlet of the waste heat boiler, unit: J / h.

9. The method for testing and calculating the efficiency of a gas turbine waste heat boiler according to claim 1, characterized in that... The formula for calculating the heat loss of the waste heat boiler in step eleven is as follows: In the formula: q rs ----- Waste heat boiler heat loss, unit: J / h; The efficiency calculation formula for a waste heat boiler is as follows: η=(H r -H c -q rs )×100 / H r unit:%.

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