Thermal calculation method, system and equipment for variable working condition during vaporization of waste heat boiler economizer and medium

Abstract

The invention belongs to the field of gas-steam combined cycle units, and discloses a thermodynamic calculation method, system, equipment and medium for the vaporization time-varying working condition of a waste heat boiler economizer, and the method comprises the steps: calculating a first water side heat exchange amount value, a second water side heat exchange amount value and a first deviation value of the economizer based on related parameters of the economizer; if the first deviation value is smaller than the first residual error standard, whether the water side outlet enthalpy value of the economizer is smaller than the water side saturated water enthalpy value or not is judged; if the water side outlet enthalpy value of the economizer is larger than the water side saturated water enthalpy value, the economizer is divided into a first part and a second part; calculating a third water side heat exchange amount value, a fourth water side heat exchange amount value and a second deviation value of the second part; and if the second deviation value is smaller than the second residual standard, key data of the economizer under the variable working condition are output. By judging the state of the working medium at the water side outlet of the economizer, the variable working condition thermal performance during vaporization of the outlet of the economizer can be calculated more accurately, and the efficiency of a waste heat boiler and even a combined cycle unit is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas-steam combined cycle units, and in particular to a thermal calculation method, system, equipment and medium for time-varying working conditions of a waste heat boiler economizer during vaporization. Background Art

[0002] In recent years, in order to cope with the severe challenges posed by the large-scale access of intermittent and fluctuating renewable energy to the safe and stable operation of the power grid, the installed capacity of efficient and flexible gas-fired generators has continued to grow. Since combined cycle units usually undertake peak load regulation tasks and gas turbines are extremely sensitive to changes in environmental parameters, combined cycle units are often operated under variable conditions. As the hub connecting gas turbines and steam turbines, the accurate calculation of the thermal performance of waste heat boilers under variable conditions is very important for analyzing and diagnosing the overall performance of combined cycle units under variable conditions.

[0003] The waste heat boiler is generally composed of multiple economizers, evaporators and superheaters connected in series. The overall variable operating condition calculation of the waste heat boiler is calculated by independently calculating the variable operating conditions of multiple components and then solving them jointly. In general, the working conditions of the economizer, evaporator and superheater inlet and outlet are usually determined. However, when the deviates far from the design operating conditions, the water side outlet of the last economizer is easily heated to wet saturated steam and contains a small amount of steam. At this time, the traditional variable operating condition theory of the waste heat boiler economizer will no longer be applicable, which may cause distortion of the calculation results and make it impossible to accurately calculate the overall variable operating condition thermal performance of the waste heat boiler. Summary of the invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a thermal calculation method and system for time-varying operating conditions of a waste heat boiler economizer vaporization to solve the problem that when the actual operation of the waste heat boiler deviates greatly from the design operating conditions, the water side outlet of the last economizer vaporizes, and the traditional economizer variable operating condition calculation method cannot accurately calculate the overall variable operating condition thermal performance of the waste heat boiler.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for calculating the thermal power of a waste heat boiler economizer under time-varying vaporization conditions, comprising: Get economizer related parameters; Based on the economizer related parameters, a first water-side heat exchange value, a second water-side heat exchange value, and a first deviation between the first water-side heat exchange value and the second water-side heat exchange value of the economizer are calculated; If the first deviation value is less than the first residual standard, determining whether the water-side outlet enthalpy of the economizer is less than the water-side saturated water enthalpy; If the outlet enthalpy of the economizer on the water side is greater than the saturated water enthalpy on the water side, the economizer is divided into a first part and a second part; Calculating a third water-side heat exchange value, a fourth water-side heat exchange value, and a second deviation between the third water-side heat exchange value and the fourth water-side heat exchange value of the second part; If the second deviation value is smaller than the second residual standard, the key data of the economizer under variable operating conditions are output.

[0007] As a preferred solution of the thermal calculation method for the time-varying working condition of the waste heat boiler economizer vaporization described in the present invention, the first water side heat exchange value and the second water side heat exchange value of the economizer are calculated based on the relevant parameters of the economizer, including: Based on the relevant parameters of the economizer design working condition and the variable working condition, the water side pressure drop, the product of the first total heat transfer coefficient and the total heat exchange area, and the first water side heat exchange value of the economizer under the variable working condition are calculated; Based on the water side pressure drop, the product of the first total heat transfer coefficient and the total heat exchange area, and the first water side heat exchange value, combined with the input parameters when the economizer changes operating conditions, the second water side heat exchange value when the economizer changes operating conditions is obtained.

[0008] As a preferred solution of the thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization described in the present invention, the first deviation value includes: If the first deviation value is less than the first residual standard, the water side outlet pressure, temperature and enthalpy value and the flue gas side inlet temperature of the economizer under the changed operating condition are output; If the first deviation value is not less than the first residual standard, the first water-side heat exchange value is updated by the Newton-Raphson algorithm, and the first deviation value is iteratively calculated and compared with the first residual standard until the first deviation is less than the first residual standard.

[0009] As a preferred solution of the thermal calculation method for the time-varying working condition of the waste heat boiler economizer vaporization described in the present invention, wherein: judging whether the water side outlet enthalpy of the economizer is less than the saturated water enthalpy of the water side includes: If the outlet enthalpy of the economizer on the water side is less than the saturated water enthalpy on the water side, the calculation ends and the key data of the economizer under variable operating conditions are output; If the outlet enthalpy of the economizer on the water side is not less than the saturated water enthalpy on the water side, the economizer is divided into a first part and a second part; The first part is the process of heating supercooled water to saturated water, and the second part is the process of heating saturated water to wet saturated steam.

[0010] As a preferred solution of the thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization described in the present invention, wherein: calculating the third water side heat exchange value and the fourth water side heat exchange value of the second part includes: Calculate the inlet flue gas temperature, outlet saturated water temperature and heat exchange ratio of the first part; Calculate the heat exchange value of the third water side of the second part; Based on the inlet flue gas temperature, outlet saturated water temperature, heat exchange ratio of the first part and the third water side heat exchange value of the second part, the fourth water side heat exchange value is obtained.

[0011] As a preferred solution of the thermal calculation method for the time-varying working condition of the waste heat boiler economizer vaporization described in the present invention, if the second deviation value is less than the second residual standard, the key data of the economizer under the variable working condition is output, including: If the second deviation value is less than the second residual standard, the outlet pressure, temperature and enthalpy of the water side and the inlet temperature of the flue gas side under the variable operating condition of the economizer are output; If the second deviation value is not less than the second residual standard, the third water-side heat exchange value is updated by the Newton-Raphson algorithm, and the second deviation value is iteratively calculated and compared with the second residual standard until the second deviation is less than the second residual standard.

[0012] As a preferred solution of the thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization described in the present invention, wherein: economizer related parameters include economizer design working condition parameters and variable working condition parameters; The design operating parameters include the product of the second total heat transfer coefficient and the total heat exchange area, the heat dissipation coefficient, the inlet and outlet pressure, temperature and flow rate of the water side, and the inlet and outlet composition, temperature and flow rate of the flue gas side; The variable operating parameters include the water side inlet pressure, temperature and flow rate, and the flue gas side outlet composition, temperature and flow rate.

[0013] Another object of the present invention is to provide a thermal calculation system for the time-varying working conditions of the waste heat boiler economizer vaporization.

[0014] In order to solve the above technical problems, the present invention provides the following technical solutions: a thermal calculation system for time-varying working conditions of a waste heat boiler economizer vaporization, comprising: Data acquisition module, used to obtain economizer related parameters; A first calculation module is used to calculate a first water-side heat exchange value, a second water-side heat exchange value, and a first deviation between the first water-side heat exchange value and the second water-side heat exchange value of the economizer based on the economizer related parameters; A first judgment module is used to judge whether the water-side outlet enthalpy of the economizer is less than the saturated water enthalpy of the water side if the first deviation value is less than the first residual standard; if the water-side outlet enthalpy of the economizer is greater than the saturated water enthalpy of the water side, divide the economizer into a first part and a second part; A second calculation module, used for calculating a third water-side heat exchange value, a fourth water-side heat exchange value, and a second deviation between the third water-side heat exchange value and the fourth water-side heat exchange value of the second part; The second judgment module is used to output key data under the variable operating condition of the economizer if the second deviation value is less than a second residual standard.

[0015] The present invention provides a computer device, comprising a memory and a processor, wherein the memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of a thermal calculation method for time-varying operating conditions of a waste heat boiler economizer vaporization are implemented.

[0016] The present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, can implement the steps of the thermal calculation method for the time-varying working condition of the waste heat boiler economizer vaporization.

[0017] Beneficial effects of the present invention: The present invention solves the problem of distorted results of traditional calculation methods when vaporizing at the economizer outlet. When vaporization occurs at the water side outlet of the last economizer of the waste heat boiler in the case of frequent variable operating conditions of the gas-steam combined cycle unit, the parameters such as the average logarithmic temperature difference, heat exchange, water side outlet enthalpy value, and flue gas inlet temperature of the economizer calculated by the traditional method have large deviations. However, the present invention divides the economizer under vaporization conditions into two parts for calculation by judging the state of the working medium at the water side outlet of the economizer, so that the calculation process is more in line with the actual heat exchange process. Compared with the traditional method, the water side outlet enthalpy value and flue gas side inlet temperature calculated by the present invention are closer to the actual values, and can more accurately calculate the variable operating condition thermal performance when vaporizing at the economizer outlet, providing a calculation basis for the safe and efficient operation of the waste heat boiler and even the combined cycle unit under variable conditions, which is helpful to optimize the unit operating parameters, improve energy utilization efficiency, and enhance the adaptability and stability of the combined cycle unit under complex conditions such as peak load regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0019] Figure 1 The schematic diagram of the general flow logic of the thermal calculation method of the time-varying working condition of the waste heat boiler economizer vaporization according to one embodiment of the present invention.

[0020] Figure 2A schematic diagram of the overall process logic of a conventional method for thermal calculation of time-varying conditions of a waste heat boiler economizer vaporization according to an embodiment of the present invention.

[0021] Figure 3 It is a schematic diagram of the overall process logic of a newly added method of the thermal calculation method for the time-varying working condition of the waste heat boiler economizer vaporization described in one embodiment of the present invention.

[0022] Figure 4 It is a schematic diagram of the temperature variation of the unsteamed condition at the economizer outlet in the thermal calculation method of the time-varying condition of the steaming economizer of a waste heat boiler described in one embodiment of the present invention.

[0023] Figure 5 It is a schematic diagram of temperature variation of the vaporization condition of the economizer outlet in the thermal calculation method of the time-varying vaporization condition of the waste heat boiler economizer described in one embodiment of the present invention.

[0024] In the figure: Figure 2 This is the flow chart of the traditional method for thermal calculation of the time-varying working condition of the waste heat boiler economizer vaporization. Figure 3 This is a new method flow chart of the thermal calculation of the waste heat boiler economizer vaporization time-varying condition, based on Figure 2 After outputting the water side outlet pressure, temperature, enthalpy value and the flue gas side inlet temperature under the economizer's changed operating conditions, the present invention further judges the economizer and re-outputs the water side outlet pressure, temperature, enthalpy value and the flue gas side inlet temperature under the economizer's changed operating conditions. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0026] Example 1, reference Figure 1~Figure 5 , as an embodiment of the present invention, provides a thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization, comprising: S100: obtaining economizer related parameters; Preferably, the economizer related parameters include economizer design operating condition parameters and variable operating condition parameters; In the embodiment of the present invention, the design operating condition parameters include the product of the second total heat transfer coefficient and the total heat exchange area, the heat dissipation coefficient, the inlet and outlet pressure, temperature and flow rate of the water side, and the inlet and outlet composition, temperature and flow rate of the flue gas side, etc.; In the embodiment of the present invention, the variable operating parameters include the water side inlet pressure, temperature and flow rate, the flue gas side outlet composition, temperature and flow rate, various residual standards and the initial value of the economizer heat exchange etc.

[0027] S102: Calculating a first water-side heat exchange value, a second water-side heat exchange value, and a first deviation between the first water-side heat exchange value and the second water-side heat exchange value of the economizer based on relevant parameters of the economizer; Preferably, based on the relevant parameters of the economizer design working condition and the variable working condition, the water side pressure drop, the product of the first total heat transfer coefficient and the total heat exchange area, and the first water side heat exchange value of the economizer under the variable working condition are calculated; In the embodiment of the present invention, the water side pressure drop calculation formula when the economizer changes working conditions is: , in, is the water side pressure drop when the economizer changes operating conditions, is the water side inlet flow rate when the economizer changes working conditions, is the water side inlet flow rate of the economizer under design conditions, This is the water side pressure drop at the economizer design condition.

[0028] In the embodiment of the present invention, the water side pressure drop calculation formula under the economizer design working condition is: ,

[0029] in, is the water side pressure drop of the economizer under design conditions, is the water side inlet pressure of the economizer under design conditions, It is the water side outlet pressure of the economizer under design conditions.

[0030] In the embodiment of the present invention, the water side outlet pressure calculation formula when the economizer changes working conditions is: , in, is the water side inlet pressure when the economizer changes working condition, is the water side inlet pressure when the economizer changes working condition, It is the water side pressure drop when the economizer changes operating conditions.

[0031] In the embodiment of the present invention, the calculation formula of the product of the first total heat transfer coefficient and the total heat exchange area when the economizer changes working conditions is: , in, It is the product of the first total heat transfer coefficient and the total heat exchange area when the economizer changes working conditions. It is the product of the second total heat transfer coefficient and the total heat exchange area under the design condition of the economizer. is the flue gas outlet flow rate when the economizer changes working conditions, It is the flue gas outlet flow rate at the economizer design condition.

[0032] It should be noted that the inlet and outlet flow rates of the water side of the economizer are the same, and the inlet and outlet compositions and flow rates of the flue gas side are the same.

[0033] In the embodiment of the present invention, the calculation formula of the heat exchange value of the first water side when the economizer changes working conditions is: , in, is the heat exchange value of the first water side when the economizer changes working conditions, is the water side heat exchange value of the economizer under design conditions, is the water side inlet flow rate when the economizer changes working conditions, It is the water side inlet flow rate at the economizer design condition.

[0034] In the embodiment of the present invention, the calculation formula of the water side heat exchange value under the design working condition of the economizer is: , in, is the water side heat exchange value of the economizer under design conditions, and The water outlet pressure and temperature of the economizer under design conditions. and The water side inlet pressure and temperature of the economizer under design conditions, It is the water side inlet flow rate at the economizer design condition.

[0035] Preferably, based on the water side pressure drop, the product of the first total heat transfer coefficient and the total heat exchange area, and the first water side heat exchange value, combined with the input parameters of the economizer when the operating condition changes, the second water side heat exchange value of the economizer when the operating condition changes is obtained; In the embodiment of the present invention, the input parameters of the economizer when the operating condition changes include the flue gas side inlet temperature, the water side outlet temperature and the logarithmic mean temperature difference.

[0036] In the embodiment of the present invention, the calculation formula of the heat exchange value of the second water side when the economizer changes working conditions is: , in, is the heat exchange value of the second water side when the economizer changes working conditions, It is the product of the first total heat transfer coefficient and the total heat exchange area when the economizer changes working conditions. It is the logarithmic mean temperature difference when the economizer changes its operating conditions.

[0037] In the embodiment of the present invention, the calculation formula of the logarithmic mean temperature difference when the economizer changes working conditions is: , , , , , in, is the logarithmic mean temperature difference when the economizer changes its working condition, is the inlet temperature of the economizer flue gas side, is the outlet temperature of the economizer flue gas side, is the economizer water outlet temperature, is the economizer water side inlet temperature, is the water side inlet flow rate when the economizer changes working conditions, is the economizer water side outlet pressure, is the water side outlet enthalpy value when the economizer changes working conditions, is the economizer water side inlet pressure, is the heat exchange value of the first water side when the economizer changes working conditions, is the composition of the flue gas outlet of the economizer, is the inlet enthalpy of the economizer flue gas side, is the flue gas outlet flow rate when the economizer changes working conditions, is the economizer heat dissipation coefficient.

[0038] Preferably, the calculation formula of the first deviation value is: , in, is the first deviation value, is the heat exchange value of the first water side when the economizer changes working conditions, It is the heat exchange value of the second water side when the economizer changes its operating condition.

[0039] S104: if the first deviation value is less than the first residual standard, determine whether the water-side outlet enthalpy of the economizer is less than the saturated water enthalpy of the water-side; if the water-side outlet enthalpy of the economizer is greater than the saturated water enthalpy of the water-side, divide the economizer into a first part and a second part; Preferably, if the first deviation value is less than the first residual standard, the water side outlet pressure, temperature and enthalpy value and the flue gas side inlet temperature when the economizer changes operating conditions are output; Preferably, if the first deviation value is not less than the first residual standard, the first water-side heat exchange value is updated by the Newton-Raphson algorithm, and the first deviation value is iteratively calculated and compared with the first residual standard until the first deviation is less than the first residual standard.

[0040] In an optional embodiment, the first residual criterion may be set to , , .

[0041] Preferably, judging whether the water-side outlet enthalpy of the economizer is less than the water-side saturated water enthalpy includes: If the enthalpy value at the water side outlet of the economizer is less than the enthalpy value of the saturated water on the water side, the calculation is completed and the key data of the economizer under the variable operating condition are output; the key data include the water side outlet pressure, temperature and enthalpy value and the flue gas side inlet temperature when the economizer is under the variable operating condition; In the embodiment of the present invention, the calculation formulas for the economizer water side outlet enthalpy and the water side saturated water enthalpy are: , , in, is the water side outlet enthalpy value when the economizer changes working conditions, is the saturated water enthalpy at the water side outlet, is the water outlet temperature of the economizer when the operating condition changes, It is the water side outlet pressure when the economizer changes operating conditions.

[0042] If the outlet enthalpy of the economizer on the water side is not less than the saturated water enthalpy on the water side, the economizer is divided into a first part and a second part; The first part is the process of heating supercooled water to saturated water, and the second part is the process of heating saturated water to wet saturated steam.

[0043] S106: calculating the third water-side heat exchange value, the fourth water-side heat exchange value, and the second deviation between the third water-side heat exchange value and the fourth water-side heat exchange value of the second part; Preferably, the inlet flue gas temperature, outlet saturated water temperature and heat exchange ratio of the first part are calculated; In the embodiment of the present invention, the calculation formulas for the inlet flue gas temperature, outlet saturated water temperature and heat exchange ratio of the first part are: , , , , , in, is the inlet flue gas temperature of the first part of the economizer, is the composition of the flue gas outlet of the economizer, is the flue gas inlet enthalpy of the first part of the economizer, is the flue gas outlet flow rate when the economizer changes working conditions, is the outlet temperature of the economizer flue gas side, is the saturated water enthalpy at the economizer water side outlet, is the economizer water side inlet pressure, is the economizer water side inlet temperature, is the water side inlet flow rate when the economizer changes working conditions, is the economizer heat dissipation coefficient, is the outlet temperature of the first part of the economizer water side, is the economizer water side outlet pressure, is the heat exchange ratio of the first part of the economizer, It is the product of the first total heat transfer coefficient and the total heat exchange area when the economizer changes working conditions. is the logarithmic mean temperature difference of the first section of the economizer.

[0044] Preferably, the third water-side heat exchange value of the second part is calculated; In the embodiment of the present invention, the third water side heat exchange value is equal to the initial value of the economizer heat exchange .

[0045] Preferably, the fourth water side heat exchange value is obtained based on the inlet flue gas temperature, the outlet saturated water temperature, the heat exchange ratio of the first part and the third water side heat exchange value of the second part; In the embodiment of the present invention, the calculation formula of the fourth water side heat exchange value is: , in, is the heat exchange value of the fourth water side when the economizer changes working conditions, is the heat exchange ratio of the first part, It is the product of the first total heat transfer coefficient and the total heat exchange area when the economizer changes working conditions. is the logarithmic mean temperature difference of the second section of the economizer.

[0046] Preferably, the calculation formula of the second deviation value is: , in, is the second deviation value, is the heat exchange value of the third water side when the economizer changes working conditions, It is the heat exchange value of the fourth water side when the economizer changes its operating condition.

[0047] S108: If the second deviation value is less than the second residual standard, output key data under the economizer variable operating condition; Preferably, if the second deviation value is less than the second residual standard, the water side outlet pressure, temperature and enthalpy value and the flue gas side inlet temperature under the economizer variable operating condition are output; Preferably, if the second deviation value is not less than the second residual standard, the third water-side heat exchange value is updated by the Newton-Raphson algorithm, and the second deviation value is iteratively calculated and compared with the second residual standard until the second deviation is less than the second residual standard.

[0048] In an optional embodiment, the second residual criterion may be set to , , .

[0049] like Figure 4 As shown in the figure, when the economizer outlet is not vaporized, the temperature change trend of the flue gas and water is relatively smooth, and the traditional variable operating condition calculation method can meet the demand.

[0050] like Figure 5 As shown, when the economizer outlet is vaporized, the temperature of the water will remain constant from the beginning to the end of vaporization.

[0051] Therefore, if the traditional method is used for calculation, the result may be distorted. Therefore, the present invention takes this situation into consideration and divides the economizer into two parts for calculation. One part is to heat the subcooled water to saturated water, and the other part is to heat the saturated water to wet saturated steam.

[0052] Example 2, refer to Table 1 and Figure 4 and Figure 5 Based on the previous embodiment, this embodiment provides an application case of a thermal calculation method for time-varying conditions of a waste heat boiler economizer vaporization to illustrate the feasibility and beneficial effects of our solution.

[0053] Depend on Figure 4 and Figure 5 It can be seen that if the traditional method is used for calculation, the average logarithmic temperature difference of the economizer will be large, resulting in excessive heat exchange, which will lead to excessive enthalpy value at the water side outlet and flue gas inlet temperature. The calculation method of the present invention is closer to the actual heat exchange process, so it can more accurately calculate the variable working conditions when the economizer outlet vaporizes.

[0054] The performance assessment condition of the high-pressure final economizer of a three-pressure reheat type waste heat boiler without supplementary combustion in a certain combined cycle unit is taken as the design condition, and the steaming condition at the outlet of a certain economizer is taken as the variable condition. The traditional method and the method proposed in the present invention are used for calculation respectively, and the calculation results are shown in Table 1.

[0055] Table 1 Comparison of the calculation results of the method of the present invention under variable working conditions with the traditional method , It can be seen from Table 1 that, when the water side outlet pressure and temperature are the same, the water side outlet enthalpy value calculated by the traditional method is 1355.60 kJ / kg, and the flue gas side inlet temperature is 309.32°C; while the water side outlet enthalpy value calculated by the present invention is 1337.12 kJ / kg, and the flue gas side inlet temperature is 307.89°C.

[0056] The water side outlet enthalpy calculated by the present invention is 18.48 kJ / kg lower than that of the traditional method, and the flue gas side inlet temperature is 1.43°C lower. This shows that the present invention can more accurately reflect the real thermal conditions of the economizer outlet during vaporization, avoid misjudgment of the equipment operating status due to calculation deviation, and provide more reliable technical support for the efficient and stable operation of the gas-steam combined cycle unit.

[0057] Embodiment 3 is the third embodiment of the present invention, which is different from the first two embodiments in that: If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0058] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0059] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0060] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0061] Embodiment 4 is the fourth embodiment of the present invention, which provides a thermal calculation system for time-varying working conditions of a waste heat boiler economizer vaporization, including: Data acquisition module, used to obtain economizer related parameters; A first calculation module is used to calculate a first water-side heat exchange value, a second water-side heat exchange value, and a first deviation between the first water-side heat exchange value and the second water-side heat exchange value of the economizer based on relevant parameters of the economizer; A first judgment module is used to judge whether the water-side outlet enthalpy of the economizer is less than the saturated water enthalpy of the water side if the first deviation value is less than the first residual standard; if the water-side outlet enthalpy of the economizer is greater than the saturated water enthalpy of the water side, the economizer is divided into a first part and a second part; A second calculation module, used for calculating a third water-side heat exchange value, a fourth water-side heat exchange value, and a second deviation between the third water-side heat exchange value and the fourth water-side heat exchange value of the second part; The second judgment module is used to output key data under the economizer variable operating condition if the second deviation value is less than the second residual standard.

[0062] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization, characterized in that: include: Get economizer related parameters; Based on the economizer related parameters, a first water-side heat exchange value, a second water-side heat exchange value, and a first deviation between the first water-side heat exchange value and the second water-side heat exchange value of the economizer are calculated; If the first deviation value is less than the first residual standard, determining whether the water-side outlet enthalpy of the economizer is less than the water-side saturated water enthalpy; If the outlet enthalpy of the economizer on the water side is greater than the saturated water enthalpy on the water side, the economizer is divided into a first part and a second part; Calculating a third water-side heat exchange value, a fourth water-side heat exchange value, and a second deviation between the third water-side heat exchange value and the fourth water-side heat exchange value of the second part; If the second deviation value is smaller than the second residual standard, the key data of the economizer under variable operating conditions are output.

2. A thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization as claimed in claim 1, characterized in that: Based on the economizer related parameters, calculating the first water side heat exchange value and the second water side heat exchange value of the economizer includes: Based on the relevant parameters of the economizer design working condition and the variable working condition, the water side pressure drop, the product of the first total heat transfer coefficient and the total heat exchange area, and the first water side heat exchange value of the economizer under the variable working condition are calculated; Based on the water side pressure drop, the product of the first total heat transfer coefficient and the total heat exchange area, and the first water side heat exchange value, combined with the input parameters when the economizer changes operating conditions, the second water side heat exchange value when the economizer changes operating conditions is obtained.

3. A thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization as claimed in claim 2, characterized in that: The first deviation value includes: If the first deviation value is less than the first residual standard, the water side outlet pressure, temperature and enthalpy value and the flue gas side inlet temperature of the economizer under the changed operating condition are output; If the first deviation value is not less than the first residual standard, the first water-side heat exchange value is updated by the Newton-Raphson algorithm, and the first deviation value is iteratively calculated and compared with the first residual standard until the first deviation is less than the first residual standard.

4. A thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization as claimed in claim 3, characterized in that: Determine whether the water-side outlet enthalpy of the economizer is less than the saturated water enthalpy of the water-side, including: If the outlet enthalpy of the economizer on the water side is less than the saturated water enthalpy on the water side, the calculation ends and the key data of the economizer under variable operating conditions are output; If the outlet enthalpy of the economizer on the water side is not less than the saturated water enthalpy on the water side, the economizer is divided into a first part and a second part; The first part is the process of heating supercooled water to saturated water, and the second part is the process of heating saturated water to wet saturated steam.

5. A thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization as claimed in claim 4, characterized in that: Calculating the third water-side heat exchange value and the fourth water-side heat exchange value of the second part includes: Calculate the inlet flue gas temperature, outlet saturated water temperature and heat exchange ratio of the first part; Calculate the heat exchange value of the third water side of the second part; Based on the inlet flue gas temperature, outlet saturated water temperature, heat exchange ratio of the first part and the third water side heat exchange value of the second part, the fourth water side heat exchange value is obtained.

6. A thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization as claimed in claim 5, characterized in that: If the second deviation value is less than the second residual standard, key data of the economizer under variable operating conditions are output, including: If the second deviation value is less than the second residual standard, the outlet pressure, temperature and enthalpy value of the water side and the inlet temperature of the flue gas side under the variable working condition of the economizer are output; If the second deviation value is not less than the second residual standard, the third water-side heat exchange value is updated by the Newton-Raphson algorithm, and the second deviation value is iteratively calculated and compared with the second residual standard until the second deviation is less than the second residual standard.

7. A thermal calculation method for time-varying working conditions of a waste heat boiler economizer vaporization as claimed in claim 1, characterized in that: Economizer related parameters include economizer design operating parameters and variable operating parameters; The design operating parameters include the product of the second total heat transfer coefficient and the total heat exchange area, the heat dissipation coefficient, the inlet and outlet pressure, temperature and flow rate of the water side, and the inlet and outlet composition, temperature and flow rate of the flue gas side; The variable operating parameters include the water side inlet pressure, temperature and flow rate, and the flue gas side outlet composition, temperature and flow rate.

8. A heat calculation system for time-varying working conditions of a waste heat boiler economizer under vaporization, using a heat calculation method for time-varying working conditions of a waste heat boiler economizer under vaporization according to any one of claims 1 to 7, characterized in that: include: Data acquisition module, used to obtain economizer related parameters; A first calculation module is used to calculate a first water-side heat exchange value, a second water-side heat exchange value, and a first deviation between the first water-side heat exchange value and the second water-side heat exchange value of the economizer based on the economizer related parameters; A first judgment module is used to judge whether the water-side outlet enthalpy of the economizer is less than the saturated water enthalpy of the water side if the first deviation value is less than the first residual standard; if the water-side outlet enthalpy of the economizer is greater than the saturated water enthalpy of the water side, divide the economizer into a first part and a second part; A second calculation module, used for calculating a third water-side heat exchange value, a fourth water-side heat exchange value, and a second deviation between the third water-side heat exchange value and the fourth water-side heat exchange value of the second part; The second judgment module is used to output key data under the variable operating condition of the economizer if the second deviation value is less than a second residual standard.

9. A computer device comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the thermal calculation method for time-varying operating conditions of the waste heat boiler economizer vaporization are implemented as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the thermal calculation method for time-varying operating conditions of a waste heat boiler economizer vaporization as described in any one of claims 1 to 7.

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