Gas-fired power plant waste heat boiler gas-heat coupling calculation method, system, device and medium

Abstract

The application provides a gas-heat coupling calculation method, system, device and medium for a waste heat boiler of a gas power plant, and the method comprises the following steps: establishing a waste heat boiler operation parameter set according to a waste heat boiler device to be studied; the waste heat boiler operation parameter set comprises device rated design parameters, device actual average operation parameters and device upper unit flue gas emission data; determining a waste heat boiler flue gas input flow upper limit value and a waste heat boiler flue gas input flow lower limit value according to preset waste heat boiler heat output parameters and the waste heat boiler operation parameter set; and solving a waste heat boiler input air extraction mass flow through a preset iterative decomposition algorithm according to the waste heat boiler flue gas input flow upper limit value and the waste heat boiler flue gas input flow lower limit value. The application can accurately describe the real waste heat boiler operation condition through analyzing the heat transfer process of unit air extraction in the waste heat boiler, and can effectively improve the precision of system optimization scheduling and control.

Description

Technical Field

[0001] This invention relates to the field of thermal power engineering technology, and in particular to a method, system, computer equipment, and storage medium for calculating gas-heat coupling in waste heat boilers of gas-fired power plants. Background Technology

[0002] In engineering applications, waste heat boilers are commonly used energy conversion devices in combined gas-steam cycles or various exhaust-powered multi-energy systems. These systems recover waste heat from the exhaust gas of generating units (coal-fired, gas-fired, etc.) and supply steam through water-gas heat exchange. Existing research mainly abstracts the process of the unit's exhaust gas flowing through the waste heat boiler, heating water in ambient temperature water pipes into hot steam to meet the heat energy needs of centralized heating or industrial users as a one-time heat exchange process. This process is described using simple linearization and a waste heat recovery coefficient to mathematically model the performance of the waste heat boiler. Furthermore, power balance is a primary focus in system analysis.

[0003] However, in real waste heat boiler systems, industrial condensate undergoes a complete phase change from liquid to gas within the boiler. This phase change is not a one-time event but rather a multi-stage heat transfer process involving the economizer, evaporator, and superheater. The actual heating power of the waste heat boiler is the heat transferred to the secondary side by the extraction medium through mixed flow heat exchange. Therefore, the direct control of the waste heat boiler's heat output is not the heat output from the upstream unit, but rather the extraction rate of the upstream unit. A complex relationship exists between the two, and this relationship changes with the operating conditions of the waste heat boiler. Clearly, existing calculation methods that abstract waste heat boiler performance into a waste heat recovery coefficient and provide a simple linear representation, while simplifying the system problem to some extent and facilitating its use in operation optimization and control, cannot accurately describe the actual operating conditions of a waste heat boiler. Their reliability and stability are low, and they cannot reliably and effectively improve the accuracy of system optimization scheduling and control. Summary of the Invention

[0004] The purpose of this invention is to provide a gas-heat coupling calculation method for waste heat boilers in gas-fired power plants. By considering the multi-stage heat transfer process between condensate and unit exhaust gas caused by the internal structure of the waste heat boiler, an iterative decomposition algorithm is used to obtain the relationship between thermal output and extraction gas volume. This effectively solves the application defect of existing waste heat recovery coefficient expressions that treat the extraction gas input of the waste heat boiler as a direct control variable rather than the boiler thermal power. It explores the complex relationship between extraction gas flow rate and thermal power, and provides a reliable and stable numerical model that can accurately describe the actual operation of the waste heat boiler, providing a reliable guarantee for improving the accuracy of system optimization scheduling and control.

[0005] To achieve the above objectives, it is necessary to provide a method, system, computer equipment, and storage medium for calculating gas-heat coupling in waste heat boilers of gas-fired power plants, addressing the aforementioned technical problems.

[0006] In a first aspect, embodiments of the present invention provide a method for calculating gas-heat coupling in a waste heat boiler of a gas-fired power plant, the method comprising the following steps:

[0007] Based on the waste heat boiler components to be studied, a set of waste heat boiler operating parameters is established; the set of waste heat boiler operating parameters includes the rated design parameters of the equipment, the actual average operating parameters of the equipment, and the flue gas emission data of the upstream unit of the equipment.

[0008] Based on the preset waste heat boiler heat output parameters and the waste heat boiler operating parameter set, determine the upper limit value and the lower limit value of the waste heat boiler flue gas input flow rate;

[0009] Based on the upper limit and lower limit of the flue gas input flow rate of the waste heat boiler, the mass flow rate of the waste heat boiler input extraction gas is calculated using a preset iterative decomposition algorithm.

[0010] Furthermore, the step of establishing a set of operating parameters for the waste heat boiler based on the waste heat boiler components under study includes:

[0011] The rated design parameters of the waste heat boiler are obtained by reading the equipment nameplate; the rated design parameters include the total heat exchange area of ​​the waste heat boiler, the economizer heat transfer coefficient, the evaporator heat transfer coefficient, and the superheater heat transfer coefficient.

[0012] The actual average operating parameters of the waste heat boiler equipment are obtained through the safety instrumented system and the distributed control system. The actual average operating parameters of the equipment include the condensate input flow rate of the waste heat boiler, the steam heating temperature of the waste heat boiler, the exhaust inlet temperature, and the standard phase change temperature of the condensate.

[0013] The waste heat boiler equipment's upstream unit flue gas emission data is acquired through a distributed control system.

[0014] Based on the rated design parameters of the equipment, the actual average operating parameters of the equipment, and the flue gas emission data of the upstream unit of the equipment, a set of operating parameters for the waste heat boiler is established.

[0015] Furthermore, the step of determining the upper limit and lower limit of the flue gas input flow rate of the waste heat boiler based on the preset waste heat boiler thermal output parameters and the waste heat boiler operating parameter set includes:

[0016] Based on the flue gas emission data of the upstream unit of the equipment, the maximum emission value of the unit during the sampling period is obtained, and the maximum emission value of the unit during the sampling period is used as the upper limit value of the flue gas input flow of the waste heat boiler.

[0017] Based on the constraint of the complete phase change process of the condensate in the waste heat boiler, the lower limit of the flue gas input flow rate of the waste heat boiler is obtained; the constraint of the complete phase change process is:

[0018] T wg,out >T hrsg,in

[0019] Among them, T wg,out and T hrsg,in These represent the exhaust temperature of the waste heat boiler flue gas and the input temperature of the waste heat boiler condensate, respectively.

[0020] Further, the step of calculating the input extraction mass flow rate of the waste heat boiler based on the upper limit and lower limit of the waste heat boiler flue gas input flow rate using a preset iterative decomposition algorithm includes:

[0021] The upper limit of the flue gas input flow rate of the waste heat boiler and the lower limit of the flue gas input flow rate of the waste heat boiler are respectively used as the initial value of the upper boundary of the extraction mass flow rate and the initial value of the lower boundary of the extraction mass flow rate. Based on the initial value of the upper boundary of the extraction mass flow rate and the initial value of the lower boundary of the extraction mass flow rate, the calculation step size and convergence accuracy of the preset iterative decomposition algorithm are determined.

[0022] The update mode of the extraction mass flow rate in a single iteration calculation is determined, and the updated key parameters of the waste heat boiler system are calculated. Based on the key parameters of the waste heat boiler system, the equivalent heat transfer area is obtained. The key parameters of the waste heat boiler system include heat transfer parameters, temperature parameters, and equivalent heat transfer area parameters.

[0023] Based on the comparative analysis of the equivalent heat exchange area and the total heat exchange area of ​​the waste heat boiler, update the upper or lower bound of the extraction mass flow rate.

[0024] The preset iterative decomposition algorithm is executed according to the calculation step size, and the input extraction mass flow rate of the waste heat boiler is obtained when the convergence accuracy is reached.

[0025] Furthermore, the heat exchange parameters include the equivalent heat exchange of the superheater, the equivalent heat exchange of the evaporator, and the equivalent heat exchange of the economizer;

[0026] The temperature parameters include the intermediate temperature of the waste heat boiler flue gas after heat exchange in the heat exchanger, the intermediate temperature of the waste heat boiler flue gas after heat exchange in the evaporator, the exhaust temperature of the waste heat boiler flue gas, and the input temperature of the waste heat boiler condensate.

[0027] The equivalent heat exchange area parameters include the equivalent heat exchange area of ​​the economizer, the equivalent heat exchange area of ​​the evaporator, and the equivalent heat exchange area of ​​the superheater.

[0028] Furthermore, the steps of calculating the updated key parameters of the waste heat boiler system and obtaining the equivalent heat exchange area based on the key parameters of the waste heat boiler system include:

[0029] The temperature parameters are obtained based on the heat exchange parameters; the temperature parameters are expressed as follows:

[0030]

[0031] In the formula,

[0032]

[0033]

[0034] in, and T represents the intermediate temperature of the waste heat boiler flue gas after heat exchange in the heat exchanger, the intermediate temperature of the waste heat boiler flue gas after heat exchange in the evaporator, the input temperature of the waste heat boiler condensate, and the discharge temperature of the waste heat boiler flue gas at the k-th iteration, respectively. wg,in and T hrsg,out These represent the exhaust gas inlet temperature of the waste heat boiler and the steam supply temperature of the waste heat boiler, respectively. and Let m represent the equivalent heat transfer of the economizer, evaporator, and superheater in the waste heat boiler at the k-th iteration; water Indicates the condensate input flow rate of the waste heat boiler; c water c represents the specific heat capacity of water; wg This indicates the specific heat capacity of the flue gas. This represents the actual mass flow rate of the waste heat boiler during the k-th iteration. and These represent the upper and lower bounds of the waste heat boiler extraction mass flow rate at the k-th iteration, respectively; q represents the latent heat of water; Q represents the preset waste heat boiler thermal output parameters; T P Indicates the standard phase transition temperature of condensate;

[0035] Based on the temperature parameter and the heat transfer parameter, the equivalent heat transfer area parameter is obtained; the equivalent heat transfer area parameter is expressed as:

[0036]

[0037] in, and Let k represent the equivalent heat transfer areas of the economizer, evaporator, and superheater in the waste heat boiler, respectively, during the k-th iteration; sm k zf and k grThese represent the economizer heat transfer coefficient, evaporator heat transfer coefficient, and superheater heat transfer coefficient in a waste heat boiler, respectively.

[0038] The equivalent heat transfer area is obtained based on the aforementioned equivalent heat transfer area parameters; the equivalent heat transfer area is expressed as:

[0039]

[0040] in, This represents the equivalent heat transfer area in the k-th iteration.

[0041] Furthermore, the step of updating the upper or lower bound of the extraction mass flow rate based on the comparative analysis of the equivalent heat exchange area and the total designed heat exchange area of ​​the waste heat boiler includes:

[0042] If the equivalent heat exchange area is less than the total designed heat exchange area of ​​the waste heat boiler, the lower bound of the extraction mass flow rate is updated according to the first update formula; otherwise, the upper bound of the extraction mass flow rate is updated according to the second update formula. The first update formula is expressed as:

[0043]

[0044] in, and These represent the lower bound of the waste heat boiler extraction mass flow rate and the actual extraction mass flow rate of the waste heat boiler at the kth iteration, respectively. Indicates the calculation step size for a single iteration;

[0045] The second update formula is expressed as:

[0046]

[0047] in, This represents the upper bound of the waste heat boiler extraction mass flow rate during the k-th iteration.

[0048] Secondly, embodiments of the present invention provide a gas-heat coupling calculation system for waste heat boilers in gas-fired power plants, the system comprising:

[0049] The parameter acquisition module is used to establish a set of operating parameters for the waste heat boiler based on the waste heat boiler components to be studied. The set of operating parameters includes the rated design parameters of the equipment, the actual average operating parameters of the equipment, and the flue gas emission data of the upstream unit of the equipment.

[0050] The limit determination module is used to determine the upper limit value and the lower limit value of the flue gas input flow rate of the waste heat boiler based on the preset waste heat boiler thermal output parameters and the waste heat boiler operating parameter set.

[0051] The iterative solution module is used to solve the waste heat boiler input extraction mass flow rate by using a preset iterative decomposition algorithm based on the upper limit value and the lower limit value of the waste heat boiler flue gas input flow rate.

[0052] Thirdly, embodiments of the present invention also provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0053] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-described method.

[0054] The present application provides a method, system, computer equipment, and storage medium for calculating the gas-thermal coupling of waste heat boilers in gas-fired power plants. The method establishes a set of waste heat boiler operating parameters, including rated design parameters, actual average operating parameters, and flue gas emission data from the upstream unit, based on the waste heat boiler components under study. It then determines the upper and lower limits of the waste heat boiler flue gas input flow rate based on preset waste heat boiler thermal output parameters and the set of operating parameters. Finally, it solves for the waste heat boiler input extraction mass flow rate using a preset iterative decomposition algorithm, based on the upper and lower limits of the waste heat boiler flue gas input flow rate. Compared with existing technologies, this gas-heat coupling calculation method for waste heat boilers in gas-fired power plants analyzes the multi-stage heat transfer process between condensate and unit exhaust gas caused by the internal structure of the waste heat boiler (economizer, evaporator, superheater). It proposes an iterative method to accurately calculate the exhaust gas input quality of the waste heat boiler, provides a reliable and stable numerical model that can accurately describe the actual operation of the waste heat boiler, explores the complex relationship between exhaust gas flow rate and thermal power, effectively solves the application defect of existing waste heat recovery coefficient expressions that treat the exhaust gas input of the waste heat boiler as a direct control variable rather than the boiler thermal power, and improves the accuracy of system optimization scheduling and control. Attached Figure Description

[0055] Figure 1 This is a schematic diagram illustrating the application scenario of the gas-heat coupling calculation method for waste heat boilers in gas-fired power plants in this embodiment of the invention.

[0056] Figure 2 This is a schematic diagram of the gas-heat coupling relationship of the waste heat boiler in a gas-fired power plant in an embodiment of the present invention;

[0057] Figure 3 This is a flowchart illustrating the gas-heat coupling calculation method for waste heat boilers in gas-fired power plants in an embodiment of the present invention.

[0058] Figure 4This is a schematic diagram of the iterative calculation of the input extraction mass flow rate of the waste heat boiler in an embodiment of the present invention;

[0059] Figure 5 This is a schematic diagram of the gas-heat coupling calculation system for the waste heat boiler of a gas-fired power plant in an embodiment of the present invention;

[0060] Figure 6 This is an internal structural diagram of the computer device in an embodiment of the present invention. Detailed Implementation

[0061] To make the objectives, technical solutions, and beneficial effects of this application clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Obviously, the embodiments described below are only part of the embodiments of the present invention and are used to illustrate the present invention, but are not intended to limit the scope of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0062] The gas-heat coupling calculation method for waste heat boilers in gas-fired power plants provided by this invention can be applied to, for example... Figure 1 The terminal or server shown. The terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, and portable wearable devices. The server can be a standalone server or a server cluster consisting of multiple servers. The server can, according to the method of the present invention, analyze, based on the set of operating parameters of the waste heat boiler obtained through the waste heat boiler nameplate, safety instrumented system (SIS system), and distributed control system (DCS system), such as... Figure 2 The heat transfer process of multi-stage gas-heat coupling in a waste heat boiler is shown, exploring the complex relationship between extraction flow rate and thermal power. This provides a more accurate and reliable numerical model for system optimization scheduling and control, and the numerical model obtained from the analysis can be used for subsequent application services on the server or fed back to end users for viewing and use. The following embodiments will provide a detailed description of the gas-heat coupling calculation method for waste heat boilers in gas-fired power plants of the present invention.

[0063] In one embodiment, such as Figure 3 As shown, a method for calculating gas-heat coupling in waste heat boilers of gas-fired power plants is provided, including the following steps:

[0064] S11. Based on the waste heat boiler components to be studied, establish a set of operating parameters for the waste heat boiler; the set of operating parameters for the waste heat boiler includes the rated design parameters of the equipment, the actual average operating parameters of the equipment, and the flue gas emission data of the upstream unit of the equipment;

[0065] Specifically, the step of establishing a set of operating parameters for the waste heat boiler based on the waste heat boiler components under study includes:

[0066] The rated design parameters of the waste heat boiler are obtained by reading the equipment nameplate; the rated design parameters include the total heat exchange area of ​​the waste heat boiler, the economizer heat transfer coefficient, the evaporator heat transfer coefficient, and the superheater heat transfer coefficient.

[0067] The actual average operating parameters of the waste heat boiler equipment are obtained through a safety instrumented system and a distributed control system. These actual average operating parameters include the waste heat boiler condensate input flow rate, waste heat boiler steam heating temperature, exhaust gas inlet temperature, and condensate standard phase change temperature. The step of obtaining these actual average operating parameters through the safety instrumented system and distributed control system includes:

[0068] Based on the waste heat boiler structure diagram of the safety instrumented system, determine the equipment operating parameters and the corresponding equipment operating parameter labels;

[0069] Based on the distributed control system and the equipment operating parameter labels, data of each equipment operating parameter is sampled according to a preset cycle and sampling duration. The average of the sampled equipment operating parameter data is then calculated to obtain the corresponding actual average operating parameters of the equipment. For example, the condensate input flow rate of the waste heat boiler is sampled with a sampling cycle of 1 hour and a sampling duration of 365 days. After obtaining 24*365 data points, the average of the above data is calculated to obtain the actual average operating data of the condensate input flow rate of the waste heat boiler for subsequent calculations.

[0070] The waste heat boiler equipment is equipped with a distributed control system to acquire the flue gas emission data of the upstream unit. The sampling period and sampling duration of the waste heat boiler equipment are determined according to actual needs. For example, sampling is performed at a period of 1 hour to obtain the hourly flue gas emission data of the unit for 2 years (730 days in total) (24 hours a day).

[0071] Based on the rated design parameters of the equipment, the actual average operating parameters of the equipment, and the flue gas emission data of the upstream unit of the equipment, a set of operating parameters for the waste heat boiler is established.

[0072] S12. Determine the upper limit and lower limit of the flue gas input flow rate of the waste heat boiler based on the preset waste heat boiler heat output parameters and the waste heat boiler operating parameter set.

[0073] The step of determining the upper limit and lower limit of the flue gas input flow rate of the waste heat boiler based on the preset waste heat boiler thermal output parameters and the waste heat boiler operating parameter set includes:

[0074] Based on the flue gas emission data of the upstream unit of the equipment, the maximum emission value of the unit in the sampling period is obtained, and the maximum emission value of the unit in the sampling period is used as the upper limit of the flue gas input flow of the waste heat boiler; wherein, the maximum emission value of the unit in the sampling period can be understood as the maximum emission value of the unit corresponding to each sampling period within the preset sampling time.

[0075] Based on the constraint of the complete phase change process of the condensate in the waste heat boiler, the lower limit of the flue gas input flow rate of the waste heat boiler is obtained; the constraint of the complete phase change process is:

[0076] T wg,out >T hrsg,in

[0077] Among them, T wg,out and T hrsg,in These represent the exhaust temperature of the waste heat boiler flue gas and the input temperature of the waste heat boiler condensate, respectively.

[0078] Based on the heat transfer principle of waste heat boilers and constrained by the complete phase change process of condensate undergoing a complete phase change in the waste heat boiler, the extraction mass flow rate (m) of the waste heat boiler is obtained. wg The following constraints must exist:

[0079]

[0080] Where Q represents the thermal output parameter of the waste heat boiler; m wg This indicates the mass flow rate of the exhaust gas from the waste heat boiler; m water Indicates the condensate input flow rate of the waste heat boiler; T hrsg,out Indicates the steam supply temperature of the waste heat boiler; T wg,in Indicates the inlet temperature of the waste heat boiler exhaust gas; c water This indicates the specific heat capacity of water, with a typical value of 4.2 kJ / kg·℃; c wg q represents the specific heat capacity of the flue gas, with a typical value of 2 kJ / kg·℃; q represents the latent heat of water, with a typical value of 6 kJ / kg.

[0081] Therefore, the lower limit of the pumping flow rate is the minimum value of the above inequality, that is...

[0082]

[0083] S13. Based on the upper limit and lower limit of the waste heat boiler flue gas input flow rate, the waste heat boiler input extraction mass flow rate is calculated using a preset iterative decomposition algorithm; wherein, after the upper limit and lower limit of the waste heat boiler flue gas input flow rate are obtained through the above steps, Figure 1In the coupling calculation of the multi-stage gas-heat coupling relationship of the waste heat boiler shown, the initial upper and lower bounds of the extraction gas mass flow rate can be regarded as the initial upper and lower bounds, respectively. Based on these, an iterative decomposition method is used to solve for the accurate value of the extraction gas mass flow rate. It should be noted that the preset iterative decomposition algorithm can be set according to the actual application requirements. In this embodiment, it is preferred to use an algorithm based on... Figure 4 The iterative decomposition algorithm shown is used to solve the problem, resulting in a reliable and stable numerical model that can accurately describe the actual operation of the waste heat boiler.

[0084] Specifically, the step of calculating the input extraction mass flow rate of the waste heat boiler based on the upper limit and lower limit of the waste heat boiler flue gas input flow rate using a preset iterative decomposition algorithm includes:

[0085] The upper limit and lower limit of the flue gas input flow rate of the waste heat boiler are used as the initial values ​​of the upper and lower bounds of the extraction mass flow rate, respectively. Based on these initial values, the calculation step size and convergence accuracy of the preset iterative decomposition algorithm are determined. The calculation step size and convergence accuracy can be determined according to actual application requirements. The calculation step size of the iterative decomposition should not be too large or too small, and theoretically, a smaller convergence accuracy is better. However, higher accuracy requires more iterations, resulting in higher time costs. To ensure accuracy while limiting the number of iterations, this embodiment preferably sets the calculation step size to 1 / 50 of the initial interval length of the extraction mass flow rate determined by the upper and lower bounds of the extraction mass flow rate, and sets the convergence accuracy ε to 1×10⁻⁶. -3 ;

[0086] The update mode for the extraction mass flow rate in a single iteration calculation is determined, and the updated key parameters of the waste heat boiler system are calculated. Based on these key parameters, the equivalent heat transfer area is obtained. The key parameters of the waste heat boiler system include heat transfer parameters, temperature parameters, and equivalent heat transfer area parameters. While the update mode for the extraction mass flow rate in a single iteration calculation can generally be set according to application requirements, considering that the upper and lower limits of the extraction mass flow rate will affect the actual extraction mass flow rate, this embodiment preferably uses a weighted average method for updating. The calculation formula is as follows:

[0087]

[0088] Where k is the current iteration number;

[0089] based on Figure 2The waste heat boiler shown has an internal structure including an economizer, an evaporator, and a superheater. Correspondingly, the heat exchange parameters include the equivalent heat exchange of the superheater, the equivalent heat exchange of the evaporator, and the equivalent heat exchange of the economizer. The temperature parameters include the intermediate temperature of the waste heat boiler flue gas after heat exchange through the superheater, the intermediate temperature of the waste heat boiler flue gas after heat exchange through the evaporator, the exhaust temperature of the waste heat boiler flue gas, and the input temperature of the waste heat boiler condensate. The equivalent heat exchange area parameters include the equivalent heat exchange area of ​​the economizer, the equivalent heat exchange area of ​​the evaporator, and the equivalent heat exchange area of ​​the superheater.

[0090] After each iteration of the calculation updates the extraction mass flow rate according to the preset update mode, the corresponding key parameters of the waste heat boiler system can be updated synchronously based on the updated extraction mass flow rate, and the equivalent heat transfer area of ​​the current iteration can be updated based on the updated key parameters. Specifically, the steps of calculating the updated key parameters of the waste heat boiler system and obtaining the equivalent heat transfer area based on the key parameters of the waste heat boiler system include:

[0091] The temperature parameters are obtained based on the heat exchange parameters; the temperature parameters are expressed as follows:

[0092]

[0093] In the formula,

[0094]

[0095]

[0096] in, and T represents the intermediate temperature of the waste heat boiler flue gas after heat exchange in the heat exchanger, the intermediate temperature of the waste heat boiler flue gas after heat exchange in the evaporator, the input temperature of the waste heat boiler condensate, and the discharge temperature of the waste heat boiler flue gas at the k-th iteration, respectively. wg,in and T hrsg,out These represent the exhaust gas inlet temperature of the waste heat boiler and the steam supply temperature of the waste heat boiler, respectively. and Let m represent the equivalent heat transfer of the economizer, evaporator, and superheater in the waste heat boiler at the k-th iteration; water Indicates the condensate input flow rate of the waste heat boiler; c water c represents the specific heat capacity of water. wg This indicates the specific heat capacity of the flue gas. This represents the actual mass flow rate of the waste heat boiler during the k-th iteration. and These represent the upper and lower bounds of the waste heat boiler extraction mass flow rate at the k-th iteration, respectively; q represents the latent heat of water; Q represents the preset waste heat boiler thermal output parameters; TP Indicates the standard phase transition temperature of condensate;

[0097] Based on the temperature parameter and the heat transfer parameter, the equivalent heat transfer area parameter is obtained; the equivalent heat transfer area parameter is expressed as:

[0098]

[0099] in, and Let k represent the equivalent heat transfer areas of the economizer, evaporator, and superheater in the waste heat boiler, respectively, during the k-th iteration; sm k zf and k gr These represent the economizer heat transfer coefficient, evaporator heat transfer coefficient, and superheater heat transfer coefficient in a waste heat boiler, respectively.

[0100] The equivalent heat transfer area is obtained based on the aforementioned equivalent heat transfer area parameters; the equivalent heat transfer area is expressed as:

[0101]

[0102] in, This represents the equivalent heat transfer area in the k-th iteration;

[0103] like Figure 4 As shown, based on the comparative analysis of the equivalent heat exchange area and the total designed heat exchange area of ​​the waste heat boiler, the upper or lower bound of the extraction mass flow rate is updated; specifically, the step of updating the upper or lower bound of the extraction mass flow rate based on the comparative analysis of the equivalent heat exchange area and the total designed heat exchange area of ​​the waste heat boiler includes:

[0104] If the equivalent heat exchange area is less than the total designed heat exchange area of ​​the waste heat boiler, the lower bound of the extraction mass flow rate is updated according to the first update formula; otherwise, the upper bound of the extraction mass flow rate is updated according to the second update formula. The first update formula is expressed as:

[0105]

[0106] in, and These represent the lower bound of the waste heat boiler extraction mass flow rate and the actual extraction mass flow rate of the waste heat boiler at the kth iteration, respectively. Indicates the calculation step size for a single iteration;

[0107] The second update formula is expressed as:

[0108]

[0109] in, This represents the upper bound of the waste heat boiler extraction mass flow rate at the k-th iteration;

[0110] The preset iterative decomposition algorithm is executed according to the calculated step size, and the waste heat boiler input extraction mass flow rate is obtained when the convergence accuracy is reached. The waste heat boiler input extraction mass flow rate can be understood as the precise value of the waste heat boiler input extraction mass flow rate that meets the corresponding accuracy requirements for iterative convergence. It should be noted that when updating the upper bound of the waste heat boiler extraction mass flow rate in each iteration, the lower bound remains unchanged; similarly, when updating the lower bound of the waste heat boiler extraction mass flow rate, the upper bound remains unchanged. After updating either the upper or lower bound of the waste heat boiler extraction mass flow rate, the absolute value of the difference between the upper and lower bounds is recalculated, and the convergence accuracy requirements are determined accordingly. If satisfied, the iteration stops, and the required waste heat boiler input extraction mass flow rate is obtained.

[0111] This embodiment, based on the internal structure of the waste heat boiler, obtains a set of waste heat boiler operating parameters, including rated design parameters, actual average operating parameters, and flue gas emission data from the upstream unit. Combined with preset waste heat boiler thermal output parameters, it determines the upper and lower limits of the waste heat boiler flue gas input flow rate. Based on these upper and lower limits, and combined with the analysis of the multi-stage heat transfer process between condensate and unit exhaust gas, a preset iterative decomposition algorithm is used to solve for the waste heat boiler input extraction mass flow rate. This method, based on the full-process analysis of multi-stage heat transfer in the waste heat boiler, proposes an iterative method for accurately calculating the waste heat boiler exhaust gas extraction mass flow rate. It provides a reliable and stable numerical model that accurately describes the actual operation of the waste heat boiler, explores the complex relationship between extraction flow rate and thermal power, and effectively addresses the shortcomings of existing waste heat recovery coefficient expressions that treat the waste heat boiler extraction input as a direct control variable rather than boiler thermal power, thus effectively improving the accuracy of system optimization scheduling and control.

[0112] In one embodiment, such as Figure 5 As shown, a gas-heat coupling calculation system for waste heat boilers in gas-fired power plants is provided, the system comprising:

[0113] The parameter acquisition module 1 is used to establish a set of operating parameters for the waste heat boiler based on the waste heat boiler components to be studied. The set of operating parameters for the waste heat boiler includes the rated design parameters of the equipment, the actual average operating parameters of the equipment, and the flue gas emission data of the upstream unit of the equipment.

[0114] Limit determination module 2 is used to determine the upper limit value and the lower limit value of the flue gas input flow rate of the waste heat boiler based on the preset waste heat boiler heat output parameters and the waste heat boiler operating parameter set;

[0115] The iterative solution module 3 is used to solve the waste heat boiler input extraction mass flow rate based on the upper limit value and the lower limit value of the waste heat boiler flue gas input flow rate, using a preset iterative decomposition algorithm.

[0116] Specific limitations regarding the gas-heat coupling calculation system for waste heat boilers in gas-fired power plants can be found in the limitations of the gas-heat coupling calculation method for waste heat boilers in gas-fired power plants mentioned above, and will not be repeated here. Each module in the aforementioned gas-heat coupling calculation system for waste heat boilers in gas-fired power plants can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0117] Figure 6 An internal structural diagram of a computer device is shown in one embodiment. This computer device may specifically be a terminal or a server. Figure 6 As shown, the computer device includes a processor, memory, network interface, display, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The network interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a gas-thermal coupling calculation method for waste heat boilers in gas-fired power plants. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0118] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computing devices may include more or fewer components than those shown in the figure, or combine certain components, or have the same component arrangement.

[0119] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described above.

[0120] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0121] In summary, the present invention provides a gas-heat coupling calculation method, system, computer equipment, and storage medium for waste heat boilers in gas-fired power plants. The method establishes a set of waste heat boiler operating parameters based on the waste heat boiler components under study, including rated design parameters, actual average operating parameters, and flue gas emission data from the upstream unit. It then determines the upper and lower limits of the waste heat boiler flue gas input flow rate based on preset waste heat boiler thermal output parameters and the set of operating parameters. Finally, based on these limits, the calculation is performed using pre-set parameters. An iterative decomposition algorithm is proposed to solve the technical solution for the mass flow rate of the exhaust gas input of a waste heat boiler. This method analyzes the multi-stage heat transfer process between condensate and unit exhaust gas caused by the internal structure of the waste heat boiler (economizer, evaporator, superheater). It proposes an iterative method to accurately calculate the mass flow rate of the exhaust gas input of the waste heat boiler, provides a reliable and stable numerical model that can accurately describe the actual operation of the waste heat boiler, and explores the complex relationship between the exhaust gas flow rate and the thermal power. It effectively solves the application defect of existing waste heat recovery coefficient expressions that treat the exhaust gas input of the waste heat boiler as a direct control variable rather than the boiler thermal power, and improves the accuracy of system optimization scheduling and control.

[0122] The various embodiments in this specification are described in a progressive manner. For directly identical or similar parts of the embodiments, refer to each other. Each embodiment focuses on its differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0123] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this invention, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A method for calculating gas-heat coupling in a waste heat boiler of a gas-fired power plant, characterized in that, The method includes the following steps: Based on the waste heat boiler components to be studied, a set of waste heat boiler operating parameters is established; the set of waste heat boiler operating parameters includes the rated design parameters of the equipment, the actual average operating parameters of the equipment, and the flue gas emission data of the upstream unit of the equipment. Based on the preset waste heat boiler heat output parameters and the waste heat boiler operating parameter set, determine the upper limit value and the lower limit value of the waste heat boiler flue gas input flow rate; Based on the upper limit and lower limit of the flue gas input flow rate of the waste heat boiler, the input extraction mass flow rate of the waste heat boiler is calculated using a preset iterative decomposition algorithm, including: The upper limit of the flue gas input flow rate of the waste heat boiler and the lower limit of the flue gas input flow rate of the waste heat boiler are respectively used as the initial value of the upper boundary of the extraction mass flow rate and the initial value of the lower boundary of the extraction mass flow rate. Based on the initial value of the upper boundary of the extraction mass flow rate and the initial value of the lower boundary of the extraction mass flow rate, the calculation step size and convergence accuracy of the preset iterative decomposition algorithm are determined. The update mode of the extraction mass flow rate in a single iteration calculation is determined, and the updated key parameters of the waste heat boiler system are calculated. Based on the key parameters of the waste heat boiler system, the equivalent heat transfer area is obtained. The key parameters of the waste heat boiler system include heat transfer parameters, temperature parameters, and equivalent heat transfer area parameters. Based on the comparative analysis of the equivalent heat exchange area and the total heat exchange area of ​​the waste heat boiler, update the upper or lower bound of the extraction mass flow rate. The preset iterative decomposition algorithm is executed according to the calculation step size, and the input extraction mass flow rate of the waste heat boiler is obtained when the convergence accuracy is reached.

2. The gas-heat coupling calculation method for waste heat boilers in gas-fired power plants as described in claim 1, characterized in that, The steps for establishing a set of operating parameters for the waste heat boiler based on the waste heat boiler components under study include: The rated design parameters of the waste heat boiler are obtained by reading the equipment nameplate; the rated design parameters include the total heat exchange area of ​​the waste heat boiler, the economizer heat transfer coefficient, the evaporator heat transfer coefficient, and the superheater heat transfer coefficient. The actual average operating parameters of the waste heat boiler equipment are obtained through the safety instrumented system and the distributed control system. The actual average operating parameters of the equipment include the condensate input flow rate of the waste heat boiler, the steam heating temperature of the waste heat boiler, the exhaust inlet temperature, and the standard phase change temperature of the condensate. The waste heat boiler equipment's upstream unit flue gas emission data is acquired through a distributed control system. Based on the rated design parameters of the equipment, the actual average operating parameters of the equipment, and the flue gas emission data of the upstream unit of the equipment, a set of operating parameters for the waste heat boiler is established.

3. The gas-heat coupling calculation method for waste heat boilers in gas-fired power plants as described in claim 2, characterized in that, The step of determining the upper limit and lower limit of the flue gas input flow rate of the waste heat boiler based on the preset waste heat boiler thermal output parameters and the waste heat boiler operating parameter set includes: Based on the flue gas emission data of the upstream unit of the equipment, the maximum emission value of the unit during the sampling period is obtained, and the maximum emission value of the unit during the sampling period is used as the upper limit value of the flue gas input flow of the waste heat boiler. Based on the constraint of the complete phase change process of the condensate in the waste heat boiler, the lower limit of the flue gas input flow rate of the waste heat boiler is obtained; the constraint of the complete phase change process is: in, and These represent the exhaust temperature of the waste heat boiler flue gas and the input temperature of the waste heat boiler condensate, respectively.

4. The gas-heat coupling calculation method for waste heat boilers in gas-fired power plants as described in claim 1, characterized in that, The heat exchange parameters include the equivalent heat exchange of the superheater, the equivalent heat exchange of the evaporator, and the equivalent heat exchange of the economizer. The temperature parameters include the intermediate temperature of the waste heat boiler flue gas after heat exchange in the heat exchanger, the intermediate temperature of the waste heat boiler flue gas after heat exchange in the evaporator, the exhaust temperature of the waste heat boiler flue gas, and the input temperature of the waste heat boiler condensate. The equivalent heat exchange area parameters include the equivalent heat exchange area of ​​the economizer, the equivalent heat exchange area of ​​the evaporator, and the equivalent heat exchange area of ​​the superheater.

5. The gas-heat coupling calculation method for waste heat boilers in gas-fired power plants as described in claim 4, characterized in that, The steps of calculating the updated key parameters of the waste heat boiler system and obtaining the equivalent heat exchange area based on the key parameters of the waste heat boiler system include: The temperature parameters are obtained based on the heat exchange parameters; the temperature parameters are expressed as follows: In the formula, in, , , and These represent the intermediate temperature of the waste heat boiler flue gas after heat exchange in the heat exchanger, the intermediate temperature of the waste heat boiler flue gas after heat exchange in the evaporator, the input temperature of the waste heat boiler condensate, and the discharge temperature of the waste heat boiler flue gas at the kth iteration, respectively. and These represent the exhaust gas inlet temperature of the waste heat boiler and the steam supply temperature of the waste heat boiler, respectively. , and Let represent the equivalent heat transfer of the economizer, the equivalent heat transfer of the evaporator, and the equivalent heat transfer of the superheater in the waste heat boiler at the k-th iteration, respectively. This indicates the condensate input flow rate of the waste heat boiler; This indicates the specific heat capacity of water; This indicates the specific heat capacity of the flue gas. This represents the actual mass flow rate of the waste heat boiler during the k-th iteration. and These represent the upper bound and lower bound of the waste heat boiler extraction mass flow rate at the kth iteration, respectively. Indicates the latent heat of water; This indicates the preset thermal output parameters of the waste heat boiler; Indicates the standard phase transition temperature of condensate; Based on the temperature parameter and the heat transfer parameter, the equivalent heat transfer area parameter is obtained; the equivalent heat transfer area parameter is expressed as: in, , and Let represent the equivalent heat transfer area of ​​the economizer, the equivalent heat transfer area of ​​the evaporator, and the equivalent heat transfer area of ​​the superheater in the waste heat boiler at the k-th iteration, respectively. , and These represent the economizer heat transfer coefficient, evaporator heat transfer coefficient, and superheater heat transfer coefficient in a waste heat boiler, respectively. The equivalent heat transfer area is obtained based on the aforementioned equivalent heat transfer area parameters; the equivalent heat transfer area is expressed as: in, This represents the equivalent heat transfer area in the k-th iteration.

6. The gas-heat coupling calculation method for waste heat boilers in gas-fired power plants as described in claim 1, characterized in that, The step of updating the upper or lower bound of the extraction mass flow rate based on the comparative analysis of the equivalent heat exchange area and the total designed heat exchange area of ​​the waste heat boiler includes: If the equivalent heat exchange area is less than the total designed heat exchange area of ​​the waste heat boiler, the lower bound of the extraction mass flow rate is updated according to the first update formula; otherwise, the upper bound of the extraction mass flow rate is updated according to the second update formula. The first update formula is expressed as: in, and These represent the lower bound of the waste heat boiler extraction mass flow rate and the actual extraction mass flow rate of the waste heat boiler at the kth iteration, respectively. Indicates the calculation step size for a single iteration; The second update formula is expressed as: in, This represents the upper bound of the waste heat boiler extraction mass flow rate during the k-th iteration.

7. A gas-heat coupling calculation system for waste heat boilers in gas-fired power plants, characterized in that, The system, employing the gas-heat coupling calculation method for waste heat boilers in gas-fired power plants as described in claim 1, comprises: The parameter acquisition module is used to establish a set of operating parameters for the waste heat boiler based on the waste heat boiler components to be studied. The set of operating parameters includes the rated design parameters of the equipment, the actual average operating parameters of the equipment, and the flue gas emission data of the upstream unit of the equipment. The limit determination module is used to determine the upper limit value and the lower limit value of the flue gas input flow rate of the waste heat boiler based on the preset waste heat boiler thermal output parameters and the waste heat boiler operating parameter set. The iterative solution module is used to solve the waste heat boiler input extraction mass flow rate based on the upper limit value and the lower limit value of the waste heat boiler flue gas input flow rate, using a preset iterative decomposition algorithm.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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