Method and system for real-time monitoring of energy efficiency of catalytic cracking three-machine set, electronic device and storage medium

Abstract

The application discloses a kind of catalytic cracking three-machine set energy efficiency real-time monitoring method and system, the method includes the following steps: A, construct flue gas turbine theoretical power calculation model, the mass flow of flue gas entering flue gas turbine under standard state, mixed flue gas constant-pressure specific heat capacity, flue gas turbine inlet temperature and the corrected temperature of flue gas turbine outlet under the influence of cooling steam are used to calculate flue gas turbine theoretical power;B, in the main motor is electric state, construct flue gas turbine shaft power calculation model, by main fan shaft power, gear box power consumption data, coupling power consumption data and main motor output power calculate flue gas turbine shaft power;C, the total efficiency of flue gas turbine is calculated by the ratio of flue gas turbine shaft power and flue gas turbine theoretical power;Flue gas energy recovery rate is calculated by the ratio of flue gas turbine shaft power and main fan shaft power.The application can realize three-machine set operation energy efficiency and economic real-time, accurate evaluation result by obtaining three-machine set operating parameters (including process parameters and flue gas real-time composition etc.) and inputting relevant calculation model.

Description

Technical Field

[0001] This invention relates to the field of energy efficiency monitoring technology for large-scale petrochemical units, and particularly to a method, system, electronic equipment, and storage medium for real-time energy efficiency monitoring of three units in a catalytic cracking unit. Background Technology

[0002] For a long time, sufficient attention has been paid to energy-saving optimization of production processes, but insufficient attention has been paid to energy conservation of equipment. In fact, equipment energy consumption accounts for a high proportion of the energy consumption structure of a plant. Taking the catalytic cracking unit, which has the highest energy consumption in the oil refining process, as an example, the energy consumption of its large units and pumps accounts for about 11% of the total energy consumption of the catalytic cracking unit. Therefore, it is very necessary to do a good job in equipment energy conservation.

[0003] The flue gas turbine-main blower-motor / generator unit, as the main energy recovery equipment in the catalytic cracking unit, is the core equipment of the unit. After separation and purification, the flue gas from the catalytic cracking process enters the flue gas turbine through a high-temperature flue gas butterfly valve to expand and perform work, and the energy generated is recovered by the flue gas turbine. The flue gas butterfly valve and double-acting slide valve installed in the flue gas passage are the main devices for regulating the regenerator pressure or controlling the reactor, regenerator differential pressure, and flue gas turbine speed. The main blower is generally an adjustable-blade axial flow fan. By controlling the adjustable blades, the fan airflow is automatically adjusted to effectively meet production needs. The energy recovered from the flue gas by the flue gas turbine is converted into kinetic energy from the thermal and pressure energy of the flue gas, and then the energy is directly transferred to the blower to perform work through the shaft. When the energy recovered by the flue gas turbine is less than the energy consumed by the blower, the motor operates in motor mode; otherwise, the motor operates in generator mode.

[0004] The energy efficiency of the three generating units directly affects the energy consumption of the entire plant. These units have complex structures and operating principles, numerous parameters, and strong inter-parameter interactions. Currently, there is a lack of accurate online real-time energy efficiency monitoring technology for these units. This makes it impossible to conduct timely horizontal comparisons of energy efficiency between different units using the same generating unit, and it is also inconvenient to understand the historical trends in the unit's energy consumption. Consequently, energy efficiency management lacks a clear objective, sense of urgency, and guidance for optimization, hindering the improvement of unit energy efficiency.

[0005] While existing technologies also include monitoring techniques for the energy efficiency of three-unit systems, such as the article "Efficiency Analysis of Flue Gas Machines in Catalytic Cracking Units" published in *Shandong Chemical Industry* (July 2014), which proposes a calculation method for the flue gas machine efficiency of three units (main blower + flue gas machine + motor / generator) in a catalytic cracking unit, and applies this method to a refinery with a 3.0 × 10⁻⁶ unit efficiency rating... 6 The flue gas turbine of the t / a catalytic cracking unit was calculated and analyzed. However, the operating parameters, such as the process parameters and flue gas composition obtained online, were not fully considered, making it difficult to obtain real-time and accurate evaluation results of the energy efficiency and economy of the three units.

[0006] Therefore, there is an urgent need for a method and system for real-time monitoring of the energy efficiency of three catalytic cracking units. This system would acquire the operating parameters of the three units (including process parameters and flue gas composition) online and input them into a relevant calculation model to achieve real-time and accurate evaluation results of the energy efficiency and economy of the three units.

[0007] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to provide a method and system for real-time monitoring of the energy efficiency of three catalytic cracking units. By acquiring the operating parameters of the three units (including process parameters and flue gas composition, etc.) online and inputting them into a relevant calculation model, the method can achieve real-time and accurate evaluation results of the energy efficiency and economy of the three units.

[0009] To achieve the above objectives, according to a first aspect of the present invention, the present invention provides a method for real-time monitoring of the energy efficiency of a three-unit catalytic cracking plant, comprising the following steps: A. Constructing a theoretical power calculation model for the flue gas turbine, calculating the theoretical power of the flue gas turbine using the mass flow rate of the flue gas entering the flue gas turbine under standard conditions, the specific heat capacity of the mixed flue gas at constant pressure, the inlet temperature of the flue gas turbine, and the corrected outlet temperature of the flue gas turbine under the influence of cooling steam; B. Constructing a flue gas turbine shaft power calculation model with the main motor in electric mode, calculating the flue gas turbine shaft power using the main fan shaft power, gearbox power consumption data, coupling power consumption data, and the output power of the main motor; C. Calculating the total efficiency of the flue gas turbine using the ratio of the flue gas turbine shaft power to the theoretical power of the flue gas turbine; and calculating the flue gas energy recovery rate using the ratio of the flue gas turbine shaft power to the main fan shaft power.

[0010] Furthermore, in the above technical solution, the theoretical power calculation model for the flue gas turbine is specifically as follows:

[0011] N 理 =G e ·C p ·(T e -T1);

[0012] Among them, G e The mass flow rate of the flue gas entering the flue gas turbine under standard conditions, expressed in kg / s; G p T1 is the isobaric specific heat capacity of the mixed flue gas, kJ / (kg·K); T2 is the flue gas turbine inlet temperature, K; T3 is the temperature at which the flue gas is inlet. e The corrected temperature (k) at the outlet of the flue gas turbine under the influence of cooling steam.

[0013] Furthermore, in the above technical solution, the mass flow rate G of the flue gas entering the flue gas turbine under standard conditions... eIt can be obtained by calculation as follows:

[0014] G e =ρ 烟 V1 / 60;

[0015]

[0016] Where, ρ 烟 The density of flue gas under standard conditions, kg / Nm³ 3 V1 is the volumetric flow rate of the flue gas entering the flue gas turbine under standard conditions, in Nm³. 3 / min; V1′ is the volumetric flow rate of the main fan under standard conditions, Nm³ 3 / min; γ A —Double-acting spool valve A opening degree, %; γ B For the opening degree of the double-acting spool valve B, %.

[0017] Furthermore, in the above technical solution, the specific heat capacity C of the mixed flue gas at constant pressure p It can be obtained by calculation as follows:

[0018] C p =∑C pi ·Y i / 100;

[0019] Among them, C pi Y represents the average isobaric specific heat capacity of the i-th component, in kJ / (kg·K); i Let m be the mass content of the i-th component.

[0020] Furthermore, in the above technical solution, the corrected temperature T at the flue gas turbine outlet under the influence of cooling steam... e It can be obtained by calculation as follows:

[0021]

[0022] Among them, G s The mass flow rate of cooling steam is kg / s; C ps The specific heat capacity of cooling steam at constant pressure, kJ / (kg·K); T s For cooling steam temperature, k; C pg T1 is the constant pressure specific heat capacity of the flue gas at the outlet of the flue gas turbine, kJ / (kg·k); T2 is the outlet temperature of the flue gas turbine, k.

[0023] Furthermore, in the above technical solution, the specific calculation model for the flue gas turbine shaft power is as follows:

[0024] N e =N c +N g +N p -Nm ;

[0025] Where, N c Main fan shaft power, kW; N g Power consumption of the gearbox, kW; N p Power consumption of the coupling, kW; N m The main motor output power is expressed in kW.

[0026] Furthermore, in the above technical solution, the main fan shaft power N c It can be obtained by calculation as follows:

[0027]

[0028] Wherein, P1′ is the main fan inlet pressure, MPa(a); P2′ is the main fan outlet pressure, MPa(a); and V1″ is the main fan inlet corrected volumetric flow rate, m³ / s. 3 / min; m is the variable index of the main fan; η pol The main fan has variable efficiency; η m The main fan mechanical efficiency.

[0029] Furthermore, in the above technical solution, the corrected volumetric flow rate V1″ at the main fan inlet is:

[0030]

[0031] Wherein, V1′ is the volumetric flow rate of the main fan under standard conditions, in Nm³. 3 / min; T1′ is the inlet temperature of the main fan, k.

[0032] Furthermore, in the above technical solution, the variable efficiency η of the main fan... pol It can be:

[0033]

[0034] Wherein, P1′ is the main fan inlet pressure, MPa(a); P2′ is the main fan outlet pressure, MPa(a); T2′ is the main fan outlet temperature, k; T1′ is the main fan inlet temperature, k; K 空 The air insulation index is 1.4.

[0035] Furthermore, in the above technical solution, the main motor output power N m Specifically, it can be:

[0036] N m =N 电入 -N 电损 ;

[0037] Where, N 电入 Main motor input power, kW; N电损 The main motor power loss is expressed in kW.

[0038] Furthermore, in the above technical solution, the overall efficiency of the flue gas turbine in step C is:

[0039] Where, N e N is the shaft power of the flue gas turbine. 理 This represents the theoretical power of the flue gas turbine.

[0040] Furthermore, in the above technical solution, the flue gas energy recovery rate in step C is:

[0041]

[0042] Where, N e The power of the flue gas turbine shaft is expressed in kW and N. c The main fan shaft power is expressed in kW.

[0043] According to a second aspect of the present invention, the present invention provides a real-time energy efficiency monitoring system for a three-unit catalytic cracking plant, comprising: a flue gas turbine theoretical power calculation module, which is used to construct a flue gas turbine theoretical power calculation model and calculate the theoretical power of the flue gas turbine by means of the mass flow rate of the flue gas entering the flue gas turbine under standard conditions, the specific heat capacity of the mixed flue gas at constant pressure, the flue gas turbine inlet temperature, and the flue gas turbine outlet correction temperature under the influence of cooling steam; a flue gas turbine shaft power calculation module, which is used to construct a flue gas turbine shaft power calculation model when the main motor is in motor mode and calculate the flue gas turbine shaft power by means of the main fan shaft power, gearbox power consumption data, coupling power consumption data, and the main motor output power; and an energy efficiency evaluation module, which is used to calculate the total efficiency of the flue gas turbine by means of the ratio of the flue gas turbine shaft power to the flue gas turbine theoretical power, and to calculate the flue gas energy recovery rate by means of the ratio of the flue gas turbine shaft power to the main fan shaft power.

[0044] According to a third aspect of the present invention, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform the real-time energy efficiency monitoring method for a catalytic cracking three-unit as described in any of the above technical solutions.

[0045] According to a fourth aspect of the present invention, the present invention provides a non-transitory computer-readable storage medium storing computer-executable instructions for causing a computer to execute the real-time energy efficiency monitoring method for a catalytic cracking three-unit as described in any of the above technical solutions.

[0046] Compared with the prior art, the present invention has one or more of the following beneficial effects:

[0047] 1) This invention can achieve real-time and accurate evaluation results of the energy efficiency and economy of the three units by acquiring the operating parameters of the three units (including process parameters and flue gas composition, etc.) online in real time and inputting them into the relevant flue gas turbine theoretical power calculation model and flue gas turbine shaft power calculation model;

[0048] 2) The inventors discovered through research that various parameters of cooling steam, such as mass flow rate, specific heat capacity at constant pressure, and temperature, have a certain impact on the flue gas temperature at the outlet of the flue gas turbine. The outlet temperature of the flue gas turbine is the basis for accurately calculating the theoretical power of the flue gas turbine. Therefore, this invention corrects the outlet temperature of the flue gas turbine to more accurately calculate the theoretical power of the flue gas turbine, which can provide stronger data support for the final energy efficiency monitoring.

[0049] 3) The inventors discovered through research that the opening degree of the double-acting slide valve has a certain impact on the flue gas volume flow rate. If this parameter is not considered, it will affect the calculation of the flue gas mass flow rate, and ultimately affect the accuracy of the theoretical power calculation of the flue gas hood. Therefore, this invention incorporates the collected opening degree data of the double-acting slide valve into the calculation of the flue gas mass flow rate, which can further improve the accuracy of the theoretical power calculation of the flue gas hood;

[0050] 4) This invention can not only use the calculation results of the theoretical power and shaft power of the flue gas turbine to further calculate the total efficiency of the flue gas turbine and the energy efficiency index of flue gas energy recovery rate in real time, but also calculate and output other energy efficiency indexes such as the real-time power and efficiency of the main fan and the flue gas turbine in the process of calculating and outputting the above two energy efficiency indexes, thereby effectively evaluating the operating economy of the main fan and the operating economy of the flue gas turbine.

[0051] 5) The present invention can also use the data of the above-mentioned energy efficiency indicators to make horizontal and vertical comparisons of key energy efficiency indicators, such as instantaneous horizontal comparison of energy efficiency indicators of three units of different users and vertical energy efficiency analysis and comparison of the same equipment.

[0052] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description

[0053] Figure 1 This is a flowchart illustrating the real-time energy efficiency monitoring method for three catalytic cracking units according to the present invention.

[0054] Figure 2 This is a schematic diagram of the structure of the real-time energy efficiency monitoring system for the three catalytic cracking units of the present invention.

[0055] Figure 3 This is a schematic diagram of the electronic equipment structure of the real-time energy efficiency monitoring method for three catalytic cracking units according to the present invention. Detailed Implementation

[0056] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0057] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0058] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” other elements or features will be oriented “above” the element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. Objects may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0059] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0060] The methods, systems, electronic devices, and storage media of the present invention are described in more detail below by way of specific embodiments. It should be understood that the embodiments are merely exemplary and the present invention is not limited thereto.

[0061] The inventors discovered that the three-unit system—flue gas turbine, main blower, and main motor (electric motor / generator)—is the core equipment of a catalytic cracking unit, and its energy efficiency directly affects the unit's energy consumption. The three units have complex structures and operating principles, numerous operating parameters, and strong inter-parameter coupling. However, existing technologies lack effective online and relatively accurate energy efficiency monitoring methods. Further research revealed that cooling steam is needed to prevent catalyst fines from entering the dead zone of the turbine disc, forming clumps that adhere to the disc and affect dynamic balance, and to maintain the disc temperature within the allowable range of the disc material. Experiments show that various parameters of the cooling steam, such as mass flow rate, specific heat capacity at constant pressure, and temperature, have a certain impact on the flue gas temperature at the turbine outlet. Since the flue gas turbine outlet temperature is the basis for accurately calculating the theoretical power of the flue gas turbine, the inventors corrected the outlet temperature to more accurately calculate the theoretical power of the turbine, providing stronger data support for final energy efficiency monitoring.

[0062] Further research by the inventors revealed that the primary function of the double-acting slide valve is to control the pressure of the regenerator by adjusting its opening, maintaining the pressure difference between the regenerator and the reactor at a stable value. In actual production, the reactor pressure can fluctuate. The opening of the double-acting slide valve is based on the signal of changes in the differential pressure between the two reactors, rather than solely on the pressure signal from the regenerator. Besides regulating the differential pressure, the double-acting slide valve can also be used to vent air in case of an accident to prevent overpressure in the regenerator. Therefore, the opening of the double-acting slide valve has a certain impact on the flue gas volumetric flow rate. Ignoring this parameter will affect the calculation of the flue gas mass flow rate, ultimately impacting the accuracy of the theoretical power calculation of the flue gas turbine.

[0063] Example 1

[0064] like Figure 1 As shown, this embodiment provides a method for real-time monitoring of the energy efficiency of a three-unit catalytic cracking plant. It mainly involves real-time collection of relevant operating parameters (including process parameters and flue gas composition) and real-time calculations. Ultimately, the energy efficiency of the three units is monitored and evaluated in real-time using key indicators such as the total efficiency of the flue gas turbine and the flue gas energy recovery rate. The method includes the following steps:

[0065] Step S101 involves constructing a theoretical power calculation model for the flue gas turbine. The theoretical power is calculated using the mass flow rate of the flue gas entering the turbine under standard conditions, the specific heat capacity of the mixed flue gas at constant pressure, the turbine inlet temperature, and the corrected outlet temperature of the turbine under the influence of cooling steam. During the calculation, measured input variable parameters and some input constants need to be retrieved from a real-time database. The specific implementation process of this step is as follows:

[0066] The theoretical power calculation model for the flue gas turbine is as follows:

[0067] N 理 =G e ·C p ·(T e -T1); formula (1);

[0068] In formula (1), G e The mass flow rate of the flue gas entering the flue gas turbine under standard conditions, expressed in kg / s; C p T1 is the isobaric specific heat capacity of the mixed flue gas, kJ / (kg·K); T2 is the flue gas turbine inlet temperature, K; T3 is the temperature at which the flue gas is inlet. e The corrected temperature (k) at the outlet of the flue gas turbine under the influence of cooling steam.

[0069] Furthermore, G in formula (1) e It can be calculated in the following ways (i.e., formulas 2 to 4):

[0070] G e =ρ 烟 ·V1 / 60; Formula (2);

[0071] In formula (2), ρ 烟 The density of flue gas under standard conditions, kg / Nm³ 3 V1 represents the volumetric flow rate of the flue gas entering the flue gas turbine under standard conditions, in Nm³. 3 / min. The flue gas density can be calculated using the following formula:

[0072] ρ 烟 =∑M i ·Y i / (100·22.4); Formula (3);

[0073] In formula (3), M i Y is the molecular weight of the i-th component; i Let (v) represent the molar content of the i-th component.

[0074]

[0075] In formula (4), V1′ is the volumetric flow rate of the main fan under standard conditions, in Nm³. 3 / min; γ A —Double-acting spool valve A opening degree, %; γ BThe percentage represents the opening degree of the double-acting slide valve B. It should be noted that this embodiment, when calculating the mass flow rate of the flue gas entering the flue gas turbine under standard conditions, fully considers the influence of the opening degree of the double-acting slide valves on the volumetric flow rate of the flue gas. By introducing the opening degree data of double-acting slide valves A and B, the accuracy of the final theoretical power calculation of the flue gas turbine can be effectively guaranteed. It should be noted that the maximum flow rate of the flue gas passing through the flue gas turbine is the rated flow rate of the flue gas turbine. If the calculated flow rate is greater than the rated flow rate of the flue gas turbine, it should be calculated according to the rated flow rate of the flue gas turbine.

[0076] Furthermore, C in formula (1) p It can be calculated in the following ways (i.e., formulas 5 to 8):

[0077] C p =∑C pi ·Y i / 100; Formula (5);

[0078] In formula (5), C pi Y represents the average isobaric specific heat capacity of the i-th component, in kJ / (kg·K); i Let m be the mass content of the i-th component, (m)%. This mass content data can be obtained from the refinery's LIMS real-time analysis data.

[0079] C pi (C pi Enter + C pi出 ) / 2; Formula (6);

[0080] In formula (6), C pi入 C is the isobaric specific heat capacity of the i-th component at the inlet temperature T1 of the flue gas machine (which can be retrieved from the real-time database), in kJ / (kg·k); pi出 Let T2 be the isobaric specific heat capacity of the i-th component at the outlet temperature T2 of the smoke machine (which can be retrieved from the real-time database), in kJ / (kg·k).

[0081] C pi入 =a+bT1·10 -3 +cT1 2 ·10 -6 ; Formula (7);

[0082] C pi出 =a+bT2·10 -3 +cT2 2 ·10 -6 ; Formula (8);

[0083] In formulas (7) and (8), the constants for different components are shown in Table 1:

[0084] Table 1. Isobaric specific heat constants of different components in flue gas

[0085] Components a b c <![CDATA[O2]]> 28.17 6.297 -0.7494 <![CDATA[N2]]> 27.32 6.226 -0.9502 <![CDATA[CO2]]> 26.75 42.258 -14.25

[0086] Furthermore, the flue gas turbine outlet correction temperature Te under the influence of cooling steam in formula (1) can be calculated in the following way (i.e., formulas 9 to 10):

[0087]

[0088] In formula (9), G s The mass flow rate of cooling steam is kg / s; C ps The specific heat capacity of cooling steam at constant pressure, kJ / (kg·K); T s For cooling steam temperature, k; C pg T1 is the constant pressure specific heat capacity of the flue gas at the outlet of the flue gas turbine, kJ / (kg·k); T2 is the outlet temperature of the flue gas turbine, k.

[0089]

[0090] In formula (10), a i b i c i is the constant corresponding to the i-th component, and the specific values ​​are shown in Table 1.

[0091] Thus far, step S101 has completed the calculation of the theoretical power of the flue gas turbine in formula (1) by constructing the calculation model and collecting and substituting the operating parameters.

[0092] Step S102: With the main motor in motored mode, construct a flue gas turbine shaft power calculation model. Calculate the flue gas turbine shaft power using the main fan shaft power, gearbox power consumption data, coupling power consumption data, and main motor output power. It should be noted that the main motor is in motored mode when the energy recovered by the flue gas turbine is less than the energy consumed by the main fan; it is in generator mode when the energy recovered by the flue gas turbine is greater than the energy consumed by the main fan. This step only considers the flue gas turbine shaft power calculation when the main motor is in motored mode.

[0093] The specific model for calculating the flue gas turbine shaft power in this step is as follows:

[0094] N e =N c +N g +N p -N m ; Formula (11);

[0095] In formula (11), N c Main fan shaft power, kW; N g Power consumption of the gearbox, kW; N p Power consumption of the coupling, kW; Nm The main motor output power is expressed in kW.

[0096] Furthermore, the main fan shaft power N in formula (11) c (That is, the actual power consumption of the main fan) can be calculated in the following way:

[0097]

[0098] In formula (12), P1′ is the main fan inlet pressure, MPa (a); P2′ is the main fan outlet pressure, MPa (a); and V1″ is the main fan inlet corrected volumetric flow rate, m³ / s. 3 / min; m is the variable index of the main fan; η pol The main fan has variable efficiency; η m The main fan mechanical efficiency.

[0099] The corrected volumetric flow rate V1″ at the main fan inlet is:

[0100]

[0101] In formula (13), V1′ is the volumetric flow rate of the main fan under standard conditions, in Nm³. 3 / min; T1′ is the inlet temperature of the main fan, k.

[0102] The variability index m of the main fan is:

[0103]

[0104] In formula (14), T2′ is the outlet temperature of the main fan, k; T1′ is the inlet temperature of the main fan, k.

[0105] Variable efficiency η of main fan pol for:

[0106]

[0107] In formula (15), P1′ is the inlet pressure of the main fan, MPa(a); P2′ is the outlet pressure of the main fan, MPa(a); T2′ is the outlet temperature of the main fan, k; T1′ is the inlet temperature of the main fan, k; K 空 The air insulation index is 1.4.

[0108] Furthermore, the main motor output power N in formula (11) m Specifically:

[0109] N m =N 电入 -N 电损 ; Formula (16);

[0110] In formula (16), N 电入 Main motor input power, kW; N 电损 The main motor power loss is expressed in kW.

[0111] The main motor input power is:

[0112]

[0113] In formula (17), U is the rated voltage of the main motor, U = 10kV; I is the operating current of the main motor, A; This is the main motor power factor (full load; motor data can be retrieved from the database).

[0114] The power loss of the main motor is:

[0115]

[0116] In formula (18), N0 is the no-load power of the main motor (which does not change with the motor load), kW; N 额 Rated power of the main motor (can be found in motor data), kW; N 铜 The maximum copper loss and stray loss of the main motor under full load (varying with motor load) are in kW.

[0117] The no-load power of the main motor is:

[0118]

[0119] In formula (19), The no-load power factor of the main motor (can be retrieved from motor data), for example, the no-load power factor of an 18000kW motor is 0.15.

[0120] The maximum copper loss and stray loss of the main motor under full load are:

[0121] N 铜 =N 满0 -N0 formula (20);

[0122] In formula (20), 0 represents the power consumed by the main motor itself when fully loaded, in kW.

[0123] The power consumed by the main motor itself when fully loaded is:

[0124] N 满0 =N 有入 -N 有出 Formula (21);

[0125] In formula (21), N 有入 Input active power of the main motor at full load, kW; N 有出 The active power output of the main motor at full load is expressed in kW.

[0126] The input active power of the main motor at full load is:

[0127]

[0128] In formula (22), I 额 The rated current of the main motor (can be found in the motor's factory data), A.

[0129] The main motor outputs the following active power at full load:

[0130] N 有出 =N 有入 ·η 满 Formula (23);

[0131] In formula (23), η 满 This is the motor's full-load efficiency (you can retrieve the motor's factory data).

[0132] Furthermore, the power consumption data of the gearbox in formula (11) is as follows:

[0133] N g =N m ·(1-η 齿 ) formula (24);

[0134] In formula (24), η 齿 For gearbox efficiency, η 齿 =0.985

[0135] Furthermore, the power consumption of the coupling in formula (11) is:

[0136] N p =N c ·(1-η 联 ) formula (25);

[0137] In formula (25), η 联 For coupling efficiency, η 联 =0.99.

[0138] Thus far, step S102 has completed the calculation of the flue gas turbine shaft power in formula (11) by constructing the calculation model and collecting and substituting the operating parameters.

[0139] Step S103: The overall efficiency of the flue gas turbine is calculated using the ratio of the flue gas turbine shaft power obtained in step S102 to the theoretical power of the flue gas turbine obtained in step S101; the flue gas energy recovery rate is calculated using the ratio of the flue gas turbine shaft power to the main fan shaft power obtained in step S102. This invention uses these two indicators to perform real-time evaluation of the energy efficiency of the three-unit system.

[0140] Specifically, the overall efficiency of the flue gas turbine is:

[0141]

[0142] Where, N e N is the shaft power of the flue gas turbine. 理 This represents the theoretical power of the flue gas turbine.

[0143] The flue gas energy recovery rate is:

[0144]

[0145] Where, N e The power of the flue gas turbine shaft is expressed in kW and N. c The main fan shaft power is expressed in kW.

[0146] The constants and real-time process parameter variables involved in the above calculation model of this embodiment are summarized in Tables 2 and 3 below.

[0147] Table 2 Model Input Constants Table

[0148]

[0149]

[0150] Table 3. Model Input Process Variables Table

[0151] Serial Number Process variable name symbol unit numerical values Data source 1 Range hood inlet temperature <![CDATA[t1]]> ℃ Real-time changes Real-time database 2 Smoke hood outlet temperature <![CDATA[t2]]> ℃ Real-time changes Real-time database 3 Smoke hood inlet pressure <![CDATA[p1]]> MPa(g) Real-time changes Real-time database 4 Smoke machine outlet pressure <![CDATA[p2]]> MPa(g) Real-time changes Real-time database 5 Double-acting spool valve A opening degree <![CDATA[γ A ]]> ％ Real-time changes Real-time database 6 Double-acting slide valve B opening degree <![CDATA[γ B ]]> ％ Real-time changes Real-time database 7 Cooling steam temperature ℃ Real-time changes Real-time database 8 Cooling steam flow rate kg / h Real-time changes Real-time database 9 Main fan inlet temperature <![CDATA[t1’]]> ℃ Real-time changes Real-time database 10 Main fan outlet temperature <![CDATA[t2’]]> ℃ Real-time changes Real-time database 11 Main fan inlet pressure <![CDATA[p1’]]> MPa(g) Real-time changes Real-time database 12 Main fan outlet pressure <![CDATA[p2’]]> MPa(g) Real-time changes Real-time database 13 Main airflow <![CDATA[V1’]]> <![CDATA[Nm 3 / min]]> Real-time changes Real-time database 14 Motor operating current I A Real-time changes Real-time database 15 <![CDATA[O2 content in flue gas]]> ％(v) Real-time changes LIMS 16 <![CDATA[N2 content in flue gas]]> ％(v) Real-time changes LIMS 17 <![CDATA[CO2 content in flue gas]]> ％(v) Real-time changes LIMS

[0152] Using the constants in Table 2 and the real-time process variable data in Table 3, the energy efficiency index in step S103 of this embodiment can be calculated in real time. At the same time, other energy efficiency indexes such as the real-time power and efficiency of the main fan and flue gas turbine can also be calculated. See Table 4 for details.

[0153] Table 4 Real-time power and efficiency output values ​​of main fan and flue gas turbine

[0154]

[0155]

[0156] The economic efficiency of the main fan operation can be evaluated based on the output results in Table 4 above, as shown in Table 5.

[0157] Table 5. Economic Evaluation Standards for Main Fan Operation

[0158] Serial Number <![CDATA[Variable efficiency (η pol )]]> Evaluation results 1 <![CDATA[η pol ≥0.75]]> Operating Economy 2 <![CDATA[0.7≤η pol <0.75]]> Reasonable operation 3 <![CDATA[η pol <0.7]]> Uneconomical

[0159] The economic efficiency of flue gas turbine operation can also be evaluated using the output results in Table 4 above, as shown in Table 6.

[0160] Table 6. Economic Evaluation Standards for Smoke Hood Operation

[0161] Serial Number <![CDATA[Variable efficiency (η 总 )]]> Evaluation results 1 <![CDATA[η 总 ≥0.65]]> Operating Economy 2 <![CDATA[0.6≤η 总 <0.65]]> Reasonable operation 3 <![CDATA[η 总 <0.6]]> Uneconomical

[0162] Based on the output results in Table 4 above, we can also conduct horizontal and vertical comparisons of key energy efficiency indicators, such as instantaneous horizontal comparisons of energy efficiency indicators of three units for different users and vertical energy efficiency analysis and comparison of the same equipment, which will not be detailed here.

[0163] Example 2

[0164] Combination Figure 2 As shown in the figure, this embodiment provides a real-time energy efficiency monitoring system for a three-unit catalytic cracking plant, including: a flue gas turbine theoretical power calculation module 201, a flue gas turbine shaft power calculation module 202, and an energy efficiency evaluation module 203. The flue gas turbine theoretical power calculation module 201 is used to construct a theoretical power calculation model for the flue gas turbine, calculating the theoretical power of the flue gas turbine using the mass flow rate of the flue gas entering the turbine under standard conditions, the specific heat capacity of the mixed flue gas at constant pressure, the inlet temperature of the flue gas turbine, and the corrected outlet temperature of the flue gas turbine under the influence of cooling steam. The flue gas turbine shaft power calculation module 202 is used to construct a flue gas turbine shaft power calculation model when the main motor is in motored mode, calculating the flue gas turbine shaft power using the main fan shaft power, gearbox power consumption data, coupling power consumption data, and the main motor output power. The energy efficiency evaluation module 203 is used to calculate the total efficiency of the flue gas turbine by the ratio of the flue gas turbine shaft power to the theoretical power of the flue gas turbine; and to calculate the flue gas energy recovery rate by the ratio of the flue gas turbine shaft power to the main fan shaft power. This embodiment is a system embodiment corresponding to method embodiment 1, and can achieve the same technical effect as embodiment 1.

[0165] Example 3

[0166] This embodiment provides a non-transient (non-volatile) computer storage medium storing computer-executable instructions. These instructions can execute the methods described in any of the above-described method embodiments and achieve the same technical effects. The method includes: A) constructing a theoretical power calculation model for the flue gas turbine, calculating the theoretical power of the flue gas turbine using the mass flow rate of the flue gas entering the turbine under standard conditions, the specific heat capacity of the mixed flue gas at constant pressure, the inlet temperature of the flue gas turbine, and the corrected outlet temperature of the flue gas turbine under the influence of cooling steam; B) constructing a flue gas turbine shaft power calculation model with the main motor in motor mode, calculating the flue gas turbine shaft power using the main fan shaft power, gearbox power consumption data, coupling power consumption data, and the main motor output power; C) calculating the overall efficiency of the flue gas turbine using the ratio of the flue gas turbine shaft power to the theoretical power of the flue gas turbine; and calculating the flue gas energy recovery rate using the ratio of the flue gas turbine shaft power to the main fan shaft power.

[0167] Example 4

[0168] This embodiment provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, which, when executed by a computer, cause the computer to perform the methods described in the above aspects and achieve the same technical effect. The method includes: A) constructing a theoretical power calculation model for a flue gas turbine, calculating the theoretical power of the flue gas turbine using the mass flow rate of the flue gas entering the turbine under standard conditions, the specific heat capacity of the mixed flue gas at constant pressure, the inlet temperature of the flue gas turbine, and the corrected outlet temperature of the flue gas turbine under the influence of cooling steam; B) constructing a flue gas turbine shaft power calculation model with the main motor in motor mode, calculating the flue gas turbine shaft power using the main fan shaft power, gearbox power consumption data, coupling power consumption data, and the main motor output power; C) calculating the total efficiency of the flue gas turbine using the ratio of the flue gas turbine shaft power to the theoretical power of the flue gas turbine; and calculating the flue gas energy recovery rate using the ratio of the flue gas turbine shaft power to the main fan shaft power.

[0169] Example 5

[0170] Figure 3 This is a schematic diagram of the hardware structure of the electronic device in Embodiment 5. The device includes one or more processors 610 and a memory 620. Taking one processor 610 as an example, the device may also include an input device 630 and an output device 640.

[0171] The processor 610, memory 620, input device 630 and output device 640 can be connected by a bus or other means.

[0172] The memory 620, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules. The processor 610 executes various functional applications and data processing of the electronic device by running the non-transitory software programs, instructions, and modules stored in the memory 620, thereby implementing the processing method of the above-described method embodiments.

[0173] The memory 620 may include a program storage area and a data storage area, wherein the program storage area may store the operating system and applications required for at least one function; the data storage area may store data, etc. Furthermore, the memory 620 may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 620 may optionally include memory remotely located relative to the processor 610, and these remote memories may be connected to the processing device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0174] Input device 630 can receive input digital or character information and generate signal input. Output device 640 may include display devices such as a display screen.

[0175] The one or more modules are stored in the memory 620. When executed by the one or more processors 610, they perform the following: A. Constructing a theoretical power calculation model for the flue gas turbine, calculating the theoretical power of the flue gas turbine using the mass flow rate of the flue gas entering the flue gas turbine under standard conditions, the specific heat capacity of the mixed flue gas at constant pressure, the inlet temperature of the flue gas turbine, and the corrected outlet temperature of the flue gas turbine under the influence of cooling steam; B. Constructing a flue gas turbine shaft power calculation model when the main motor is in motor mode, calculating the flue gas turbine shaft power using the main fan shaft power, gearbox power consumption data, coupling power consumption data, and the output power of the main motor; C. Calculating the total efficiency of the flue gas turbine using the ratio of the flue gas turbine shaft power to the theoretical power of the flue gas turbine; and calculating the flue gas energy recovery rate using the ratio of the flue gas turbine shaft power to the main fan shaft power.

[0176] The above-described product can execute the methods provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects for executing the methods. Technical details not described in detail in this embodiment can be found in the methods provided in other embodiments of the present invention.

[0177] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0178] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0179] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A method for real-time monitoring of the energy efficiency of a three-unit catalytic cracking plant, characterized in that, Includes the following steps: A. Construct a theoretical power calculation model for the flue gas turbine, and calculate the theoretical power of the flue gas turbine by the mass flow rate of the flue gas entering the flue gas turbine under standard conditions, the specific heat capacity of the mixed flue gas at constant pressure, the inlet temperature of the flue gas turbine, and the corrected outlet temperature of the flue gas turbine under the influence of cooling steam. The specific theoretical power calculation model for the flue gas turbine is as follows: ； in, The mass flow rate of the flue gas entering the flue gas turbine under standard conditions, expressed in kg / s; The isobaric specific heat capacity of the mixed flue gas is given in kJ / (kg·k). The inlet temperature of the flue gas turbine is K; The corrected temperature (k) at the outlet of the flue gas turbine under the influence of cooling steam; The mass flow rate of the flue gas entering the flue gas turbine under standard conditions It is obtained through the following calculation method: ； ； in, The density of flue gas under standard conditions, kg / Nm³ 3 ; The volumetric flow rate (Nm³) of the flue gas entering the flue gas turbine under standard conditions. 3 / min; Volumetric flow rate of the main fan under standard conditions, Nm 3 / min; —Double-acting spool valve A opening degree, % For the opening degree of the double-acting spool valve B, % B. With the main motor in electric mode, construct a flue gas turbine shaft power calculation model, and calculate the flue gas turbine shaft power using the main fan shaft power, gearbox power consumption data, coupling power consumption data, and main motor output power. C. Calculate the overall efficiency of the flue gas turbine by using the ratio of the flue gas turbine shaft power to the theoretical power of the flue gas turbine; calculate the flue gas energy recovery rate by using the ratio of the flue gas turbine shaft power to the main fan shaft power.

2. The method for real-time monitoring of energy efficiency of a three-unit catalytic cracking plant according to claim 1, characterized in that, The specific heat capacity at constant pressure of the mixed flue gas It is obtained through the following calculation method: ； in, Let be the average isobaric specific heat capacity of the i-th component, in kJ / (kg·k). Let m be the mass content of the i-th component.

3. The method for real-time monitoring of energy efficiency of a three-unit catalytic cracking plant according to claim 1, characterized in that, The corrected temperature of the flue gas turbine outlet under the influence of cooling steam It is obtained through the following calculation method: ； in, The mass flow rate of cooling steam is kg / s; The isobaric specific heat capacity of cooling steam, kJ / (kg·k); The temperature of the cooling steam is k; T1 is the constant pressure specific heat capacity of the flue gas at the outlet of the flue gas turbine, kJ / (kg·k); T2 is the outlet temperature of the flue gas turbine, k.

4. The method for real-time monitoring of energy efficiency of a three-unit catalytic cracking plant according to claim 1, characterized in that, The specific model for calculating the shaft power of the flue gas turbine is as follows: ； in, Main fan shaft power, kW; The power consumption of the gearbox is expressed in kW. The power consumption of the coupling is expressed in kW. The main motor output power is expressed in kW.

5. The method for real-time monitoring of energy efficiency of a three-unit catalytic cracking plant according to claim 4, characterized in that, The main fan shaft power It is obtained through the following calculation method: ； in, The main fan inlet pressure, MPa(a); Main fan outlet pressure, MPa(a); Corrected volumetric flow rate at the main fan inlet, m 3 / min; The main fan variable index; The main fan has variable efficiency; The main fan mechanical efficiency.

6. The method for real-time monitoring of energy efficiency of a three-unit catalytic cracking plant according to claim 5, characterized in that, The corrected volumetric flow rate at the main fan inlet for: ； in, Volumetric flow rate of the main fan under standard conditions, Nm 3 / min; The main fan inlet temperature, K.

7. The method for real-time monitoring of energy efficiency of a three-unit catalytic cracking plant according to claim 5, characterized in that, The variable efficiency of the main fan for: ； in, The main fan inlet pressure, MPa(a); Main fan outlet pressure, MPa(a); Main fan outlet temperature, K; Main fan inlet temperature, K; The air insulation index is 1.

4.

8. The method for real-time monitoring of energy efficiency of a three-unit catalytic cracking plant according to claim 4, characterized in that, The main motor output power Specifically: ； in, Main motor input power, kW; The main motor power loss is expressed in kW.

9. The method for real-time monitoring of energy efficiency of a three-unit catalytic cracking plant according to claim 1, characterized in that, The overall efficiency of the flue gas turbine in step C is: ； in, This refers to the shaft power of the flue gas turbine. This represents the theoretical power of the flue gas turbine. The flue gas energy recovery rate in step C is: ； in, The power of the flue gas turbine shaft is expressed in kW. The main fan shaft power is expressed in kW.

10. A real-time energy efficiency monitoring system for a three-unit catalytic cracking plant, characterized in that, The method described in any one of claims 1 to 9 includes: The flue gas turbine theoretical power calculation module is used to construct a flue gas turbine theoretical power calculation model. It calculates the theoretical power of the flue gas turbine by the mass flow rate of the flue gas entering the flue gas turbine under standard conditions, the specific heat capacity of the mixed flue gas at constant pressure, the flue gas turbine inlet temperature, and the flue gas turbine outlet correction temperature under the influence of cooling steam. The flue gas turbine shaft power calculation module is used to construct a flue gas turbine shaft power calculation model when the main motor is in electric mode. It calculates the flue gas turbine shaft power using the main fan shaft power, gearbox power consumption data, coupling power consumption data, and main motor output power. The energy efficiency assessment module is used to calculate the overall efficiency of the flue gas turbine by the ratio of the flue gas turbine shaft power to the theoretical power of the flue gas turbine; and to calculate the flue gas energy recovery rate by the ratio of the flue gas turbine shaft power to the main fan shaft power.

11. An electronic device, characterized in that, include: At least one processor; as well as A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, which, when executed by the at least one processor, causes the at least one processor to perform the real-time energy efficiency monitoring method for a catalytic cracking unit as described in any one of claims 1 to 9.

12. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer-executable instructions, which are used to cause the computer to execute the real-time energy efficiency monitoring method for a three-unit catalytic cracking plant as described in any one of claims 1 to 9.

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