A method for controlling the opening of a gas turbine gas flow valve

Abstract

The present invention discloses a method for controlling the opening of a gas flow valve of a gas turbine, and relates to the technical field of gas flow valve control of a gas turbine. The specific process is: firstly, the flow coefficients of a gas flow valve A, a gas flow valve B and a pilot flow valve are calculated respectively, and then opening instructions are outputted according to the flow coefficients to control the openings of the gas flow valve A, the gas flow valve B and the pilot flow valve respectively. The present invention can calculate and correct the opening of each flow valve through relevant actual parameters of natural gas and gas turbine operation, thereby accurately controlling the natural gas flow of the gas turbine at different stages and working conditions, and finally ensuring the safe operation of the gas turbine.

Description

Technical Field

[0001] The invention relates to the technical field of gas turbine gas flow valve control, and in particular to a method for controlling the opening of a gas turbine gas flow valve. Background Art

[0002] Gas turbines are widely used in energy, national defense, and transportation fields such as power generation, ship and locomotive power, and pipeline boosting. They are high-tech core equipment related to national security and national economic development. The natural gas of existing domestic heavy-duty gas turbines usually enters the burner for combustion in three pipelines, namely the main A gas pipeline including the gas flow valve A, the main B gas pipeline including the gas flow valve B, and the pilot gas pipeline including the pilot flow valve. For gas turbines, the control of its fuel is the core and most basic part of the entire control strategy. In order to ensure that natural gas can burn safely and stably in the gas turbine burner and meet the emission requirements of nitrogen oxides (NOx), the control system needs to adjust the natural gas flow entering the gas turbine by controlling the opening of the flow valve in the three pipelines. However, there are different stages and working conditions in the operation of gas turbines, and the natural gas flow required for each stage and working condition is different. Therefore, how to accurately control the flow of natural gas under different stages and working conditions is of great significance to the safe operation of gas turbines. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned technical problems existing in the prior art and provide a method for controlling the opening of a gas flow valve of a gas turbine. The present invention can calculate and correct the opening of each flow valve through relevant actual parameters of natural gas and gas turbine operation, thereby accurately controlling the natural gas flow of the gas turbine in different stages and working conditions, and ultimately ensuring the safe operation of the gas turbine.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A method for controlling the opening of a gas flow valve of a gas turbine, characterized in that: firstly, the flow coefficients of a gas flow valve A, a gas flow valve B and a pilot flow valve are calculated respectively, and then opening instructions are outputted according to the flow coefficients to control the openings of the gas flow valve A, the gas flow valve B and the pilot flow valve respectively;

[0006] The flow coefficient and the opening instruction are both derived based on the opening realization module, which includes a mass flow realization module, a natural gas compression coefficient realization module, a natural gas density realization module, a flow coefficient realization module, a valve flow coefficient conversion opening module and a valve opening conversion pressure difference coefficient module; wherein,

[0007] The mass flow realization module is used to calculate the natural gas mass flow according to the natural gas parameters;

[0008] The natural gas compression coefficient realization module is used to calculate the natural gas compression coefficient according to the natural gas parameters and flow valve parameters;

[0009] The natural gas density realization module is used to calculate the natural gas density according to the natural gas compression coefficient, natural gas parameters and flow valve parameters;

[0010] The flow coefficient realization module is used to calculate the flow coefficient according to the natural gas mass flow, natural gas density, natural gas parameters, flow valve parameters and valve pressure difference coefficient;

[0011] The valve flow coefficient to opening degree module is used to output the opening degree instruction according to the flow coefficient;

[0012] The valve opening to pressure differential coefficient module is used to output the valve pressure differential coefficient according to the opening instruction.

[0013] The number of the opening realization modules is three, and the three opening realization modules are respectively connected to the gas flow valve A, the gas flow valve B and the pilot flow valve.

[0014] The natural gas parameters include the natural gas heat flow, gas calorific value, gas specific gravity and specific heat ratio, and the flow valve parameters include the flow valve inlet pressure, valve inlet temperature and differential pressure; wherein,

[0015] The natural gas mass flow rate is calculated by the mass flow rate realization module according to the heat flow rate and the calorific value of the gas;

[0016] The calculated natural gas compression coefficient is calculated by the natural gas compression coefficient realization module according to the specific gravity of the gas, the pressure before the valve and the temperature before the valve;

[0017] The natural gas density is calculated by the natural gas density realization module according to the specific gravity of the gas, the pressure before the valve, the temperature before the valve and the natural gas compression coefficient;

[0018] The flow coefficient is calculated by the flow coefficient realization module according to the natural gas mass flow, specific heat ratio, natural gas density, valve front pressure, differential pressure and valve pressure differential coefficient.

[0019] Among the flow valve parameters, the pre-valve pressure and pre-valve temperature are measured by a pressure sensor and a temperature sensor respectively arranged at the front end of the flow valve, and the differential pressure is measured by a differential pressure sensor connected at both ends of the flow valve.

[0020] The advantages of adopting the present invention are:

[0021] 1. The valve opening control method of the present invention is implemented based on an opening realization module designed with six submodules. Through the six submodules of the opening realization module, the opening of each flow valve can be calculated and corrected in real time according to the relevant parameters of the natural gas required by the gas turbine and the relevant parameters of each flow valve (gas flow valve A, gas flow valve B and pilot flow valve) during actual operation, so as to accurately control the natural gas flow of the gas turbine at different stages and working conditions, and ultimately ensure the safe operation of the gas turbine.

[0022] 2. The present invention divides the valve opening control method into six sub-functions, which has a clear structure and can quickly analyze the coupling relationship between the functions, thus facilitating the debugging of the gas turbine.

[0023] 3. The present invention sets the valve flow coefficient conversion to opening degree and the valve opening conversion to differential pressure coefficient as independent functional functions, which are easy to debug and correct.

[0024] 4. The present invention converts the units of input parameters, performs fixed value processing on the parameters related to the natural gas fuel of the gas turbine, introduces some dimensionless parameters, and simplifies the control loop under the premise of ensuring the control accuracy.

[0025] 5. The present invention has been verified in actual operation on a domestically produced gas turbine with independent intellectual property rights. The gas turbine flow valve opening control is accurate and reliable, fully meeting the operating requirements of the gas turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a principle block diagram of the present invention;

[0027] Figure 2 This is the principle block diagram of the opening of the gas flow valve A;

[0028] Figure 3 This is the principle block diagram of the opening of the medium gas flow valve B;

[0029] Figure 4 This is the principle block diagram of the pilot flow valve opening;

[0030] Figure 5 Implementation block diagram of the module for mass flow;

[0031] Figure 6 The principle block diagram of the module for realizing the compression factor of natural gas;

[0032] Figure 7 Schematic diagram of the module for natural gas density implementation;

[0033] Figure 8 It is a principle block diagram of the flow coefficient realization module, the valve flow coefficient conversion opening module and the valve opening conversion pressure difference coefficient module cooperating to control the opening of the gas flow valve A;

[0034] Fig. 9 It is a principle block diagram of the flow coefficient realization module, the valve flow coefficient conversion opening module and the valve opening conversion pressure difference coefficient module cooperating to control the opening of the gas flow valve B;

[0035] Fig.10 It is a principle block diagram of the flow coefficient realization module, the valve flow coefficient conversion opening module and the valve opening conversion pressure difference coefficient module cooperating to control the opening of the pilot flow valve. DETAILED DESCRIPTION

[0036] like Figure 1 As shown, the present invention provides a method for controlling the opening of a gas flow valve of a gas turbine, wherein the gas flow valve of the gas turbine comprises a gas flow valve A, a gas flow valve B and a pilot flow valve, and the specific control method is: firstly, the flow coefficients of the gas flow valve A, the gas flow valve B and the pilot flow valve are calculated respectively, and then, according to the flow coefficient of the gas flow valve A, the flow coefficient of the gas flow valve B and the flow coefficient of the pilot flow valve, the opening instructions corresponding to the gas flow valve A, the gas flow valve B and the pilot flow valve are output respectively, so as to control the opening of the gas flow valve A, the gas flow valve B and the pilot flow valve.

[0037] In order to ensure the effective control of the opening of each flow valve, the present invention specifically sets up three opening realization modules, and connects these three opening realization modules to the gas flow valve A, gas flow valve B and pilot flow valve respectively. Based on the connected opening realization modules, the flow coefficient and opening instruction of each flow valve (gas flow valve A, gas flow valve B and pilot flow valve, the same below) are obtained by the opening realization module. Specifically,

[0038] The opening realization module includes a mass flow realization module, a natural gas compression coefficient realization module, a natural gas density realization module, a flow coefficient realization module, a valve flow coefficient conversion opening module and a valve opening conversion pressure difference coefficient module; wherein,

[0039] The mass flow realization module is used to calculate the natural gas mass flow rate according to the natural gas parameters.

[0040] The natural gas compression coefficient realization module is used to calculate the natural gas compression coefficient according to the natural gas parameters and flow valve parameters.

[0041] The natural gas density realization module is used to calculate the natural gas density based on the natural gas compression coefficient, natural gas parameters and flow valve parameters.

[0042] The flow coefficient realization module is used to calculate the flow coefficient according to the natural gas mass flow, natural gas density, natural gas parameters, flow valve parameters and valve pressure difference coefficient.

[0043] The valve flow coefficient to opening module is used to output opening instructions according to the flow coefficient.

[0044] The valve opening to pressure differential coefficient module is used to output the valve pressure differential coefficient according to the opening instruction.

[0045] It should be noted that the natural gas parameters required by the present invention include the heat flow rate, calorific value, specific gravity and specific heat ratio of natural gas, and the required flow valve parameters include the flow valve inlet pressure, inlet temperature and differential pressure. Among the flow valve parameters, the inlet pressure and inlet temperature are measured by the pressure sensor and temperature sensor respectively arranged at the front end of the flow valve, and the differential pressure is measured by the differential pressure sensor connected at both ends of the flow valve.

[0046] Furthermore, the specific parameters and calculation methods involved in the above modules are as follows:

[0047] The natural gas mass flow rate is calculated by the mass flow rate realization module according to the heat flow rate and the calorific value of the gas.

[0048] The calculated natural gas compression coefficient is calculated by a natural gas compression coefficient realization module according to the specific gravity of the fuel gas, the pressure before the valve and the temperature before the valve.

[0049] The natural gas density is calculated by a natural gas density realization module according to the specific gravity of the fuel gas, the pressure before the valve, the temperature before the valve and the natural gas compression coefficient.

[0050] The flow coefficient is calculated by the flow coefficient realization module according to the natural gas mass flow, specific heat ratio, natural gas density, valve front pressure, differential pressure and valve pressure differential coefficient.

[0051] In actual application of the present invention, the opening realization module corresponding to each flow valve receives the above-mentioned four parameters of natural gas and three parameters of the flow valve respectively, and the corresponding flow coefficient and opening instruction can be obtained after relevant processing of these parameters, thereby realizing accurate control of the opening of each flow valve and ensuring the safe operation of the gas turbine.

[0052] The present invention is fully described below by taking a domestically produced gas turbine as an example in conjunction with the accompanying drawings.

[0053] like Figure 1 As shown, the domestically produced gas turbine uses 3-way gas pipelines to enter the gas turbine burner. The 3-way pipelines are equipped with three flow valves, namely gas flow valve A, gas flow valve B and pilot flow valve, and flow valve differential pressure measuring points, flow valve inlet pressure measuring points and flow valve inlet temperature measuring points are set respectively to measure the valve differential pressure △P1, inlet pressure P1 and inlet temperature T1 of each flow valve. Among them,

[0054] The opening degree realization module of the gas turbine flow valve A receives a total of 7 types of signals, namely: the natural gas heat flow Q of the flow valve A TH1 , Gas calorific value T LHV, Gas specific gravity G g and specific heat ratio γ, differential pressure △P1 of flow valve A, pressure P1 before flow valve A and temperature T1 before flow valve A. The opening realization module of flow valve A processes the received data and outputs opening instruction D1 to control the opening of flow valve A.

[0055] The opening degree realization module of the gas turbine flow valve B receives a total of 7 types of signals, namely: the natural gas heat flow Q of the flow valve B TH2 , Gas calorific value T LHV , Gas specific gravity G g and specific heat ratio γ, differential pressure △P2 of flow valve B, pressure P2 before flow valve B and temperature T2 before flow valve B. The opening degree realization module of flow valve B processes the received data and outputs opening degree instruction D2 to control the opening degree of flow valve B.

[0056] The gas turbine pilot flow valve opening realization module receives 7 types of signals, namely: the natural gas heat flow Q TH3 , Gas calorific value T LHV , Gas specific gravity G g and specific heat ratio γ, differential pressure △P3 of the pilot flow valve, pressure P3 before the pilot flow valve and temperature T3 before the pilot flow valve. After processing the received data, the opening degree realization module of the pilot flow valve outputs the opening degree instruction D3 to control the opening degree of the pilot flow valve.

[0057] like Figure 2 As shown, the method for realizing the opening of the gas turbine flow valve A is as follows: the opening realization module of the gas flow valve A includes 6 submodules, namely, the mass flow realization module of the flow valve A, the natural gas compression coefficient realization module of the flow valve A, the natural gas density realization module of the flow valve A, the flow coefficient realization module of the flow valve A, the valve flow coefficient conversion opening module of the flow valve A and the valve opening conversion pressure difference coefficient module of the flow valve A. Among them,

[0058] Flow valve A mass flow realization module receives flow valve A natural gas thermal flow Q TH1 and gas calorific value T LHV , after processing, the mass flow W1 of the output flow valve A is sent to the flow coefficient realization module of the flow valve A.

[0059] Flow valve A Natural gas compression coefficient realization module receives gas specific gravity G g , the flow valve A front pressure P1 and the flow valve A front temperature T1, and after processing, the natural gas compression coefficient Z1 of the flow valve A is output to the flow valve A natural gas density realization module.

[0060] Flow valve A Natural gas density realization module receives gas specific gravity G g, flow valve A front pressure P1, flow valve A front temperature T1 and natural gas compression coefficient Z1, and after processing, output flow valve A natural gas density ρ1 to flow valve A flow coefficient realization module.

[0061] The flow coefficient realization module of flow valve A receives the mass flow W1, specific heat ratio γ, natural gas density ρ1, flow valve A inlet pressure P1, flow valve A differential pressure △P1 and flow valve A valve differential pressure coefficient X T1 , after processing, the output flow valve A flow coefficient K V1 To the flow valve A valve flow coefficient opening module.

[0062] The flow valve A valve opening conversion pressure difference coefficient module receives the flow valve A opening instruction D1, and after processing, outputs the flow valve A valve pressure difference coefficient X T1 To the flow valve A coefficient implementation module.

[0063] Flow valve A valve flow coefficient turn opening module receives flow valve A flow coefficient K V1 , after processing, the flow valve A opening instruction D1 is output to complete the control of the flow valve A valve opening.

[0064] like Figure 3 As shown, the method for realizing the opening of the gas turbine flow valve B is as follows: the opening realization module of the gas flow valve B includes 6 submodules, namely, the mass flow realization module of the flow valve B, the natural gas compression coefficient realization module of the flow valve B, the natural gas density realization module of the flow valve B, the flow coefficient realization module of the flow valve B, the flow coefficient conversion module of the flow valve B, and the valve opening conversion module of the flow valve B. Among them,

[0065] Flow valve B mass flow realization module receives flow valve B natural gas thermal flow Q TH2 and gas calorific value T LHV , after processing, the mass flow rate W2 of the output flow valve B is sent to the flow coefficient realization module of the flow valve B.

[0066] Flow valve B Natural gas compression coefficient realization module receives gas specific gravity G g , the flow valve B valve front pressure P2 and the flow valve B valve front temperature T2, and after processing, the natural gas compression coefficient Z2 of the flow valve B is output to the flow valve B natural gas density realization module.

[0067] Flow valve B Natural gas density realization module receives gas specific gravity G g , flow valve B valve front pressure P2, flow valve B valve front temperature T2 and natural gas compression coefficient Z2, after processing, the output flow valve B natural gas density ρ2 to the flow valve B flow coefficient realization module.

[0068] The flow coefficient realization module of flow valve B receives the mass flow W2, specific heat ratio γ, natural gas density ρ2, flow valve B valve front pressure P2, flow valve B differential pressure △P2 and flow valve B valve differential pressure coefficient X T2 , after processing, the output flow valve B flow coefficient K V2 To the flow valve B valve flow coefficient opening module.

[0069] The valve opening conversion module of flow valve B receives the opening instruction D2 of flow valve B and outputs the valve differential pressure coefficient X of flow valve B after processing. T2 To the flow valve B coefficient implementation module.

[0070] Flow valve B valve flow coefficient turn opening module receives flow valve B flow coefficient K V2 , after processing, the flow valve B opening instruction D2 is output to complete the control of the flow valve B valve opening.

[0071] like Figure 4 As shown, the valve opening realization method of the gas turbine pilot flow is as follows: the opening realization module of the gas pilot flow valve includes 6 submodules, namely, the pilot flow valve mass flow realization module, the pilot flow valve natural gas compression coefficient realization module, the pilot flow valve natural gas density realization module, the pilot flow valve flow coefficient realization module, the pilot flow valve valve flow coefficient conversion opening module, and the pilot flow valve valve opening conversion pressure difference coefficient module. Among them,

[0072] The pilot flow valve mass flow realization module receives the pilot flow valve natural gas thermal flow Q TH3 and gas calorific value T LHV , after processing, the mass flow rate W3 of the pilot flow valve is output to the pilot flow valve flow coefficient realization module.

[0073] Pilot flow valve natural gas compression coefficient realization module receives gas specific gravity G g , the pilot flow valve inlet pressure P3 and the pilot flow valve inlet temperature T3, and after processing, the natural gas compression coefficient Z3 of the pilot flow valve is output to the pilot flow valve natural gas density realization module.

[0074] Pilot flow valve natural gas density module receives gas specific gravity G g , pilot flow valve inlet pressure P3, pilot flow valve inlet temperature T3 and natural gas compression coefficient Z3, and after processing, output the pilot flow valve natural gas density ρ3 to the pilot flow valve flow coefficient realization module.

[0075] The pilot flow valve flow coefficient module receives the mass flow W3 of the pilot flow valve, the specific heat ratio γ, the natural gas density ρ3 of the pilot flow valve, the pressure P3 before the pilot flow valve, the differential pressure △P3 of the pilot flow valve and the differential pressure coefficient X of the pilot flow valve. T3, after processing, the output pilot flow valve flow coefficient K V3 To the pilot flow valve valve flow coefficient opening module.

[0076] The pilot flow valve valve opening conversion pressure difference coefficient module receives the pilot flow valve opening instruction D3, and after processing, outputs the pilot flow valve valve pressure difference coefficient to the pilot flow valve coefficient realization module.

[0077] The pilot flow valve valve flow coefficient is transferred to the opening module to receive the pilot flow valve flow coefficient K V3 , after processing, the pilot flow valve opening instruction D3 is output to complete the control of the pilot flow valve opening.

[0078] like Figure 5 As shown, the method for realizing the natural gas mass flow rate of each flow valve is:

[0079] The mass flow realization module of flow valve A receives the natural gas thermal flow Q of flow valve A. TH1 and gas calorific value T LHV Then, the heat flow Q TH1 The result of multiplication by 3.6 is divided by the calorific value of the gas T LHV , the mass flow rate W1 of flow valve A can be output.

[0080] Flow valve B mass flow realization module receives flow valve B natural gas thermal flow Q TH2 and gas calorific value T LHV Then, the heat flow Q TH2 The result of multiplication by 3.6 is divided by the calorific value of the gas T LHV , the mass flow rate W2 of flow valve B can be output.

[0081] The pilot flow valve mass flow realization module receives the pilot flow valve natural gas thermal flow Q TH3 and gas calorific value T LHV Then, the heat flow Q TH3 The result of multiplication by 3.6 is divided by the calorific value of the gas T LHV , the mass flow rate W3 of the pilot flow valve can be output.

[0082] Among them, the unit of heat flow demand is KJ / s, the unit of calorific value is MJ / kg, and the unit of mass flow is kg / h.

[0083] like Figure 6 As shown, the method for realizing the natural gas compression coefficient of each flow valve is:

[0084] The natural gas compression coefficient of the flow valve A realizes the specific gravity of the gas received by the module G g , flow valve A inlet pressure P1 and flow valve A inlet temperature T1, and after processing, the natural gas compression coefficient Z1 of flow valve A is output. The specific processing process is:

[0085] Gas specific gravity G g The result of multiplying by 1.785 enters the x of the 10x square function block. The output of the 10x square function block is multiplied by the pressure P1 in front of the flow valve A, and then multiplied by 49951. The result enters the numerator of the division function block. The temperature T1 in front of the flow valve A is added to 273.15 and multiplied by 1.8. The multiplication result is raised to the power of 3.825 and enters the denominator of the division function block. The output value after dividing the numerator and denominator of the division function block is added to 1, and then divided by 1 to output the natural gas compression coefficient Z1 of the flow valve A.

[0086] Flow valve B Natural gas compression coefficient realization module receives gas specific gravity G g , flow valve B valve front pressure P2 and flow valve B valve front temperature T2, after processing, output flow valve B natural gas compression coefficient Z1. The specific processing process is: gas specific gravity G g The result of multiplying by 1.785 enters the x of the 10x square function block. The output of the 10x square function block is multiplied by the pressure P2 in front of the flow valve B, and then multiplied by 49951. The result enters the numerator of the division function block. The temperature T2 in front of the flow valve B is added to 273.15 and multiplied by 1.8. The multiplication result is raised to the power of 3.825 and enters the denominator of the division function block. The output value after dividing the numerator and denominator of the division function block is added to 1, and then divided by 1 to output the natural gas compression coefficient Z2 of the flow valve B.

[0087] Pilot flow valve natural gas compression coefficient realization module receives gas specific gravity G g , the pilot flow valve inlet pressure P3 and the pilot flow valve inlet temperature T3, and after processing, the natural gas compression coefficient Z3 of the pilot flow valve is output. The specific processing process is:

[0088] Gas specific gravity G g The result of multiplying by 1.785 enters the x of the 10x square function block. The output of the 10x square function block is multiplied by the pressure P3 in front of the pilot flow valve, and then multiplied by 49951. The result enters the numerator of the division function block. The pilot flow valve inlet temperature T3 is added to 273.15 and multiplied by 1.8. The multiplication result is raised to the power of 3.825 and enters the denominator of the division function block. The output value after dividing the numerator and denominator of the division function block is added to 1, and then divided by 1 to output the natural gas compression coefficient Z3 of the pilot flow valve.

[0089] Among them, the specific gravity of gas G g The natural gas compression coefficient and the natural gas pressure before the valve are dimensionless parameters. The unit of the natural gas pressure before the valve is kPaG, and the unit of the temperature before the valve is ℃.

[0090] like Figure 7 As shown, the method for realizing the natural gas density of each flow valve is:

[0091] Flow valve A Natural gas density realization module receives gas specific gravity G g , flow valve A inlet pressure P1, flow valve A inlet temperature T1 and natural gas compression coefficient Z1, output flow valve A natural gas density ρ1. The specific processing process is:

[0092] Gas specific gravity G g Multiply by 28.96443, then multiply by the value of the pressure P1 before the flow valve A and 101.325, and the result enters the numerator of the division function block. The temperature T1 before the flow valve A is added to 273.15, multiplied by the natural gas compression coefficient Z1 of the flow valve A, and then multiplied by 8.3144598, and enters the denominator of the division function block. The output of the division function block after dividing the numerator and denominator is the natural gas density ρ1 of the flow valve A.

[0093] Flow valve B Natural gas density realization module receives gas specific gravity G g , flow valve B valve front pressure P2, flow valve B valve front temperature T2 and natural gas compression coefficient Z2, output flow valve B natural gas density ρ2. The specific processing process is:

[0094] Gas specific gravity G g Multiply by 28.96443, then multiply by the value of the pressure P2 in front of flow valve B and 101.325, and the result enters the numerator of the numerical division function block. The temperature T2 in front of flow valve B is added to 273.15, multiplied by the natural gas compression coefficient Z2 of flow valve B, and then multiplied by 8.3144598, and enters the denominator of the division function block. The output of the division function block after dividing the numerator and denominator is the natural gas density ρ2 of flow valve B.

[0095] Pilot flow valve natural gas density module receives gas specific gravity G g , pilot flow valve inlet pressure P3, pilot flow valve inlet temperature T3 and natural gas compression coefficient Z3, output pilot flow valve natural gas density ρ3. The specific processing process is:

[0096] Gas specific gravity G g Multiply by 28.96443, then multiply by the value of the pilot flow valve inlet pressure P3 plus 101.325, and the result enters the numerator of the numerical division function block. The pilot flow valve inlet temperature T3 is added to 273.15, multiplied by the pilot flow valve natural gas compression coefficient Z3, and then multiplied by 8.3144598, and enters the denominator of the division function block. The output of the division function block after dividing the numerator and denominator is the pilot flow valve natural gas density ρ3.

[0097] Among them, the specific gravity of gas G g The natural gas compression coefficient and the natural gas pressure before the valve are dimensionless parameters. The unit of natural gas pressure before the valve is kPaG, the unit of temperature before the valve is ℃, and the unit of natural gas density is kg / m3 .

[0098] like Figure 8 As shown, the method for realizing the opening of the flow valve A based on the cooperation of the flow coefficient realization module, the valve flow coefficient conversion opening module and the valve opening conversion pressure difference coefficient module is as follows: the flow coefficient realization module of the flow valve A receives the mass flow W1 of the flow valve A, the specific heat ratio γ, the natural gas density ρ1 of the flow valve A, the pressure P1 before the flow valve A, the differential pressure △P1 of the flow valve A and the valve pressure difference coefficient X of the flow valve A T1 , after processing, the output flow valve A flow coefficient K V1 To the flow coefficient conversion module of flow valve A. The flow valve A valve opening conversion pressure difference coefficient module receives the flow valve A opening instruction D1, and after processing, outputs the flow valve A valve pressure difference coefficient to the flow valve A flow coefficient realization module. The flow valve A valve flow coefficient conversion module receives the flow valve A flow coefficient K V1 , after processing, the flow valve A opening instruction D1 is output. The specific processing process is:

[0099] The ratio coefficient X1 is obtained by dividing the differential pressure △P1 of flow valve A by the value of the pressure P1 before flow valve A plus 101.325. The specific heat ratio γ is divided by 1.4 to obtain the specific heat ratio coefficient F γ , compare the output of the opening conversion pressure differential coefficient module of flow valve A (x1=-5%, y1=0.61; x2=0%, y2=0.61; x3=5%, y3=0.59; x4=10%, y4=0.53; x5=15%, y5=0.51; x6=20%, y6=0.48; x7=30%, y7=0.49; x8=50%, y8=0.5; x9=70%, y9=0.5; x10=80%, y10=0.51; x11=90%, y11=0.52; x12=100%, y12=0.54) with 0.1, and select the larger value as the pressure differential coefficient X of flow valve A T1 With F γ Multiply and compare the result with X1. There are two cases: X1<F γ X T1 and X1 ≥ F γ X T1 When X1<F γ X T1 When X1 is divided by 3, then divided by F γ X T1，Subtract the result from 1 to get the expansion coefficient Y1. Add 101.325 to the pressure P1 before the flow valve A, multiply it by the natural gas density ρ1 of the flow valve A, then multiply it by X1, take the square root of the value, multiply it by 3.16, multiply it by the expansion coefficient Y1, and enter the denominator of the division function block. The mass flow W1 of the flow valve A enters the numerator of the division function block. After dividing the numerator and denominator of the division function block, the flow coefficient K of the flow valve A is output. V1 When X1 ≥ F γ X T1 When 2 is divided by 3, the expansion coefficient Y1 is obtained. The pressure P1 before the flow valve A plus 101.325 is multiplied by the natural gas density ρ1 of the flow valve A, and then multiplied by F γ , then multiply by X T1 After the value is squared, it is multiplied by 3.16 and the expansion coefficient Y1, and enters the denominator of the division function block. The mass flow W1 of the flow valve A enters the numerator of the division function block. After the numerator and denominator of the division function block are divided, the flow coefficient K of the flow valve A is output. V1 . K V1 Enter the flow coefficient conversion opening module of flow valve A (x1=-5, y1=-5%; x2=0, y2=0%; x3=0.66, y3=5%; x4=1.55, y4=10%; x5=2.47, y5=15%; x6=4.07, y6=20%; x7=6.13, y7=30%; x8=10.86, y8=50%; x9=15.86, y9=70%; x10=18.01, y10=80%; x11=19.91, y11=90%; x12=21.4, y12=100%), and output the flow valve A opening command D1.

[0100] Among them, the specific heat ratio coefficient F γ , ratio coefficient X1, pressure difference coefficient X T1 , expansion coefficient Y1 and flow coefficient K V1 All are dimensionless parameters, the unit of mass flow rate W1 is kg / h, and the unit of natural gas density ρ1 is kg / m 3 , the unit of the pressure before the valve P1 is kPaG, the unit of the differential pressure △P1 is kPa, and the unit of the opening instruction D1 is %.

[0101] like Fig. 9 As shown, the method for realizing the opening of flow valve B based on the cooperation of flow coefficient realization module, valve flow coefficient conversion opening module and valve opening conversion pressure difference coefficient module is as follows: the valve flow coefficient module of flow valve B receives the mass flow W2 of flow valve B, the specific heat ratio γ, the natural gas density ρ2 of flow valve B, the pressure P2 before flow valve B, the differential pressure △P2 of flow valve B and the valve differential pressure coefficient X of flow valve B T2 , after processing, the output flow valve B flow coefficient K V2To the flow valve B valve flow coefficient conversion opening module. The flow valve B valve opening conversion pressure difference coefficient module receives the flow valve B opening instruction D2, and after processing, outputs the flow valve B valve pressure difference coefficient to the flow valve B flow coefficient realization module. The flow valve B valve coefficient module receives the flow valve B flow coefficient K V2 , after processing, the flow valve B opening instruction D2 is output. The specific processing process is:

[0102] The ratio coefficient X2 is obtained by dividing the differential pressure △P2 of flow valve B by the value of the pressure P1 before flow valve B plus 101.325. The specific heat ratio γ is divided by 1.4 to obtain the specific heat ratio coefficient F. γ , compare the output of the opening conversion pressure differential coefficient module of flow valve B (x1=-5%, y1=0.69; x2=0%, y2=0.69; x3=5%, y3=0.65; x4=10%, y4=0.55; x5=15%, y5=0.51; x6=20%, y6=0.5; x7=30%, y7=0.48; x8=40%, y8=0.49; x9=50%, y9=0.47; x10=60%, y10=0.46; x11=80%, y11=0.47; x12=100%, y12=0.48) with 0.1, and select the larger value as the pressure differential coefficient X of flow valve A T1 With F γ Multiply and compare the result with X2. There are two cases: X2<F γ X T2 and X2 ≥ F γ X T2 When X2<F γ X T2 When X2 is divided by 3, then divided by F γ X T2， Subtract the result from 1 to get the expansion coefficient Y2. Add 101.325 to the pressure P2 before the flow valve B, multiply it by the natural gas density ρ2 of the flow valve B, multiply it by X2, take the square root of the value, multiply it by 3.16, multiply it by the expansion coefficient Y2, and enter the denominator of the division function block. The mass flow rate W2 of the flow valve B enters the numerator of the division function block. After dividing the numerator and denominator of the division function block, the flow coefficient K of the flow valve B is output. V2 When X2 ≥ F γ X T2 When 2 is divided by 3, the expansion coefficient Y2 is obtained. The pressure P2 before the flow valve B is added to 101.325 and multiplied by the natural gas density ρ2 of the flow valve B, and then multiplied by F γ , then multiply by X T2After the value is squared, it is multiplied by 3.16 and the expansion coefficient Y2, and enters the denominator of the division function block. The mass flow rate W2 of the flow valve B enters the numerator of the division function block. After the numerator and denominator of the division function block are divided, the flow coefficient K of the flow valve B is output. V2 . K V2 Enter the flow coefficient conversion opening module of flow valve B (x1=-5, y1=-5%; x2=0, y2=0%; x3=0.73, y3=5%; x4=1.4, y4=10%; x5=1.9, y5=15%; x6=2.6, y6=20%; x7=4.99, y7=30%; x8=8.7, y8=40%; x9=11.98, y9=50%; x10=16.29, y10=60%; x11=22.75, y11=80%; x12=29.65, y12=100%), and output the flow valve B opening instruction D2. Specific heat ratio coefficient F γ , ratio coefficient X2, pressure difference coefficient X T2 , expansion coefficient Y2 and flow coefficient K V2 All are dimensionless parameters, the mass flow rate W2 is in kg / h, and the natural gas density ρ2 is in kg / m 3 , the unit of the pressure before the valve P2 is kPaG, the unit of the differential pressure △P2 is kPa, and the unit of the opening command D2 is %.

[0103] like Fig.10 As shown, the method for realizing the pilot flow valve opening based on the cooperation of the flow coefficient realization module, the valve flow coefficient conversion opening module and the valve opening conversion pressure difference coefficient module is as follows: the pilot flow valve valve flow coefficient module receives the mass flow W3 of the pilot flow valve, the specific heat ratio γ, the natural gas density ρ3 of the pilot flow valve, the pilot flow valve inlet pressure P3, the pilot flow valve differential pressure △P3 and the pilot flow valve valve pressure difference coefficient X T3 , after processing, the output pilot flow valve flow coefficient K V3 To the pilot flow valve flow coefficient conversion opening module. The pilot flow valve opening conversion pressure difference coefficient module receives the pilot flow valve opening instruction D3, and after processing, outputs the pilot flow valve pressure difference coefficient to the pilot flow valve flow coefficient realization module. The pilot flow valve flow coefficient conversion opening module receives the pilot flow valve flow coefficient K V3 , after processing, the pilot flow valve opening instruction D3 is output. The specific processing process is:

[0104] The pilot flow valve differential pressure △P3 divided by the pilot flow valve inlet pressure P3 plus 101.325 gives the ratio coefficient X3, and the specific heat ratio γ divided by 1.4 gives the specific heat ratio coefficient F γ, compare the output of the pilot flow valve opening conversion pressure differential coefficient module (x1=-5%, y1=0.62; x2=0%, y2=0.62; x3=5%, y3=0.62; x4=10%, y4=0.54; x5=15%, y5=0.57; x6=20%, y6=0.59; x7=40%, y7=0.6; x8=50%, y8=0.66; x9=60%, y9=0.65; x10=70%, y10=0.63; x11=90%, y11=0.66; x12=100%, y12=0.64) with 0.1, and select the larger value as the pilot flow valve pressure differential coefficient X T3 With F γ Multiply and compare the result with X3. There are two cases: X3<F γ X T3 and X3 ≥ F γ X T3 When X3<F γ X T3 When X3 is divided by 3, then divided by F γ X T3， Subtract the result from 1 to get the expansion coefficient Y3. The pilot flow valve inlet pressure P3 plus 101.325 is multiplied by the pilot flow valve natural gas density ρ3, then multiplied by X3, the value is squared, then multiplied by 3.16, multiplied by the expansion coefficient Y3, and enters the denominator of the division function block. The mass flow W3 of the pilot flow valve enters the numerator of the division function block. After the numerator and denominator of the division function block are divided, the flow coefficient K of the pilot flow valve is output. V3 When X3 ≥ F γ X T3 When 2 is divided by 3, the expansion coefficient Y3 is obtained. The pilot flow valve inlet pressure P3 plus 101.325 multiplied by the pilot flow valve natural gas density ρ3, and then multiplied by F γ , then multiply by X T3 After the value is squared, it is multiplied by 3.16 and the expansion coefficient Y3, and enters the denominator of the division function block. The mass flow rate W3 of the pilot flow valve enters the numerator of the division function block. After the numerator and denominator of the division function block are divided, the flow coefficient K of the pilot flow valve is output. V3 . K V3Enter the pilot flow valve flow coefficient conversion opening module (x1=-5, y1=-5%; x2=0, y2=0%; x3=0.69, y3=5%; x4=0.91, y4=10%; x5=1.18, y5=15%; x6=1.47, y6=20%; x7=2.71, y7=40%; x8=3.49, y8=50%; x9=5.38, y9=60%; x10=8.14, y10=70%; x11=16.89, y11=90%; x12=20.34, y12=100%), and output the pilot flow valve opening command D3. Specific heat ratio coefficient F γ , ratio coefficient X3, pressure difference coefficient X T3 , expansion coefficient Y3 and flow coefficient K V3 All are dimensionless parameters, the unit of mass flow rate W3 is kg / h, and the unit of natural gas density ρ3 is kg / m 3 , the unit of pre-valve pressure P3 is kPaG, the unit of differential pressure △P3 is kPa, and the unit of opening instruction D3 is %.

[0105] It should be noted that some specific values ​​are involved in the above specific implementation process. Since the gas turbine has certain requirements on the composition of natural gas, these values ​​are mainly related to the composition of natural gas in the gas turbine. For example, 28.96443 is the conversion of natural gas specific gravity into molar mass, 8.3144598 is the molar constant of natural gas, and 101325 is a unit of atmospheric pressure, which is related to the molecular weight of natural gas.

[0106] The above description is only a specific implementation mode of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other alternative features that are equivalent or have similar purposes; all the disclosed features, or all the steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A method for controlling the opening of a gas flow valve of a gas turbine, wherein the gas turbine uses a three-way gas pipeline to enter a gas turbine burner, and the three-way pipeline is equipped with three flow valves, namely, a gas flow valve A, a gas flow valve B and a pilot flow valve; the method is characterized in that: First, the flow coefficients of the gas flow valve A, the gas flow valve B and the pilot flow valve are calculated respectively, and then the opening instructions corresponding to the gas flow valve A, the gas flow valve B and the pilot flow valve are outputted respectively according to the flow coefficient of the gas flow valve A, the flow coefficient of the gas flow valve B and the flow coefficient of the pilot flow valve, so as to control the opening of the gas flow valve A, the gas flow valve B and the pilot flow valve; The flow coefficient and the opening instruction are both derived based on the opening realization module, which includes a mass flow realization module, a natural gas compression coefficient realization module, a natural gas density realization module, a flow coefficient realization module, a valve flow coefficient conversion opening module and a valve opening conversion pressure difference coefficient module; wherein, The mass flow realization module is used to calculate the natural gas mass flow according to the natural gas parameters; The natural gas compression coefficient realization module is used to calculate the natural gas compression coefficient according to the natural gas parameters and flow valve parameters; The natural gas density realization module is used to calculate the natural gas density according to the natural gas compression coefficient, natural gas parameters and flow valve parameters; The flow coefficient realization module is used to calculate the flow coefficient according to the natural gas mass flow, natural gas density, natural gas parameters, flow valve parameters and valve pressure difference coefficient; The valve flow coefficient to opening degree module is used to output the opening degree instruction according to the flow coefficient; The valve opening to pressure differential coefficient module is used to output the valve pressure differential coefficient according to the opening instruction; The natural gas parameters include the heat flow rate, calorific value, specific gravity and specific heat ratio of natural gas, and the flow valve parameters include the flow valve inlet pressure, inlet temperature and differential pressure; The opening degree of each flow valve is realized as follows: The mass flow realization module receives the natural gas heat flow Q TH and gas calorific value T LHV , after processing, the mass flow rate W is output to the flow coefficient realization module; Natural gas compression coefficient realization module receives gas specific gravity G g , valve front pressure P and valve front temperature T, and output natural gas compression coefficient Z to natural gas density realization module after processing; Natural gas density realization module receives gas specific gravity G g , valve front pressure P, valve front temperature T and natural gas compression coefficient Z, and output natural gas density ρ to flow coefficient realization module after processing; The valve flow coefficient realization module receives mass flow W, specific heat ratio γ, natural gas density ρ, valve front pressure P, differential pressure △P and valve pressure differential coefficient X T , output flow coefficient after treatment K V To the valve flow coefficient opening module; The valve opening to pressure differential coefficient module receives the opening command D and outputs the valve differential pressure coefficient X after processing. T To the flow coefficient realization module; The valve flow coefficient is converted to the opening module to receive the flow coefficient K V , after processing, the opening instruction D is output to complete the control of the valve opening; The method for realizing the natural gas mass flow of each flow valve is as follows: the mass flow realization module receives the natural gas heat flow Q TH and gas calorific value T LHV Then, the heat flow Q TH The result of multiplication by 3.6 is divided by the calorific value of the gas T LHV , that is, the output mass flow rate W; Among them, the unit of heat flow demand is KJ / s, the unit of calorific value is MJ / kg, and the unit of mass flow is kg / h; The method for realizing the natural gas compression coefficient of each flow valve is as follows: gas specific gravity G g The result of multiplying by 1.785 enters the x of the 10x square function block, the output of the 10x square function block is multiplied by the valve front pressure P, and then multiplied by 49951, and the result enters the numerator of the division function block; the valve front temperature T is added to 273.15 and then multiplied by 1.8, and the multiplication result is 3.825 times the power and enters the denominator of the division function block; the output value after dividing the numerator and denominator of the division function block is added to 1, and then divided by 1 to output the natural gas compression coefficient Z; The method of realizing the natural gas density of each flow valve is as follows: gas specific gravity G g Multiply by 28.96443, then multiply by the value of the sum of the valve front pressure P and 101.325, and the result enters the numerator of the numerical division function block; add the valve front temperature T to 273.15, multiply by the natural gas compression coefficient Z, and then multiply by 8.3144598, and enter the denominator of the division function block; the output after dividing the numerator and denominator of the division function block is the natural gas density ρ; The method for realizing the opening of each flow valve based on the flow coefficient realization module, the valve flow coefficient conversion opening module and the valve opening conversion pressure difference coefficient module is as follows: The differential pressure △P is divided by the value of the pressure P before the valve plus 101.325 to get the ratio coefficient X, and the specific heat ratio γ is divided by 1.4 to get the specific heat ratio coefficient F γ , compare the output of the opening conversion pressure difference coefficient module with 0.1, and select the larger value as the pressure difference coefficient X T With F γ Multiply and compare the result with X. There are two cases: X<F γ X T and X ≥ F γ X T ; When X<F γ X T When X is divided by 3, then divided by F γ X T , subtract the result from 1 to get the expansion coefficient Y; add 101.325 to the pressure P before the valve, multiply it by the natural gas density ρ, then multiply it by X, take the square root of the value, then multiply it by 3.16, multiply it by the expansion coefficient Y, enter the denominator of the division function block, the mass flow W enters the numerator of the division function block, and the numerator of the division function block is divided by the denominator to output the flow coefficient K V ; When X ≥ F γ X T 2 is divided by 3 to get the expansion coefficient Y; the pressure P before the valve plus 101.325 multiplied by the natural gas density ρ, and then multiplied by F γ , then multiply by X T After the value is squared, it is multiplied by 3.16 and the expansion coefficient Y, and enters the denominator of the division function block. The mass flow W enters the numerator of the division function block. The numerator of the division function block is divided by the denominator to output the flow coefficient K. V ; K V Enter the flow coefficient to opening module and output the opening instruction D; specific heat ratio coefficient F γ , ratio coefficient X, pressure difference coefficient X T , expansion coefficient Y and flow coefficient K V All are dimensionless parameters, the mass flow rate W is in kg / h, and the natural gas density ρ is in kg / m 3 , the unit of pressure P before the valve is kPaG, the unit of differential pressure △P is kPa, and the unit of opening command D is %.

2. A method for controlling the opening of a gas turbine gas flow valve according to claim 1, characterized in that: The number of the opening realization modules is three, and the three opening realization modules are respectively connected to the gas flow valve A, the gas flow valve B and the pilot flow valve.

3. A method for controlling the opening of a gas turbine gas flow valve according to claim 1, characterized in that: Among the flow valve parameters, the pre-valve pressure and pre-valve temperature are measured by a pressure sensor and a temperature sensor respectively arranged at the front end of the flow valve, and the differential pressure is measured by a differential pressure sensor connected at both ends of the flow valve.

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