Grid-connected off-grid waste heat power generation system

Abstract

The invention belongs to the technical field of power generation, and particularly relates to a grid-connected off-grid waste heat power generation system which is provided with a waste heat generator set and a switch cabinet group, the waste heat generator set is an equipment device for converting waste heat into electric energy, and the switch cabinet group is an equipment device for transmitting the electric energy generated by the waste heat to a local load for power supply. The switch cabinet group is connected with the commercial power grid, so that grid-connected use of the waste heat generator set and the commercial power grid is implemented, and electric energy generated by the waste heat generator set is isolated from being transmitted to the commercial power grid, so that the aim of not surfing the internet is fulfilled; meanwhile, optimization is carried out through a control system in the power transmission and utilization process. The problem that in the prior art, the utilization rate of steam waste heat is not good can be solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power generation, and in particular relates to a waste heat power generation system that is connected to a grid but not connected to the grid. Background Art

[0002] In the modern industrial production system, the sulfuric acid operation area is undoubtedly one of the important cornerstones of the chemical industry. In the sulfuric acid production process, the steam generated by the boiler contains considerable heat, and this part of the steam waste heat theoretically has great reuse value. However, for a long time, traditional sulfuric acid operation areas have mostly adopted a relatively extensive and primary treatment method when treating boiler steam waste heat, resulting in a low level of utilization efficiency.

[0003] From the current actual situation, some enterprises only use steam waste heat for some basic preheating links with limited heat exchange efficiency, such as simple preliminary heating of raw materials or some production process water. This utilization method only extracts a very small part of the energy in the steam waste heat, and a large amount of heat energy still remains in the steam and is then discharged into the atmosphere. Therefore, improving the utilization efficiency of boiler steam waste heat in sulfuric acid operation areas, converting it into electrical energy and effectively utilizing it in local loads can not only reduce the electricity cost of enterprises, but also reduce dependence on external power grids, which has important economic and environmental significance. However, the current special and efficient grid-connected and non-grid-connected power generation technology for boiler steam waste heat in sulfuric acid operation areas still has many shortcomings, and innovative technical solutions are urgently needed. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a waste heat power generation system that is connected to the grid but not connected to the grid, so as to solve the problem of poor utilization rate of steam waste heat in the prior art.

[0005] The basic solution provided by the present invention is: a waste heat power generation system that is connected to the grid but not connected to the grid, comprising a waste heat generator set, a switch cabinet set and a control system, wherein the waste heat generator set is connected to the switch cabinet set, the waste heat generator set is used to convert waste heat into electrical energy and transmit it to the switch cabinet set, the switch cabinet set is used to receive the electrical energy transmitted by the waste heat generator set and transmit it to the local load grid through distribution processing, and the control system is connected to the waste heat generator set and the switch cabinet set;

[0006] The control system includes a monitoring module, a data acquisition module, a data preprocessing module, a digital twin management module and a transmission strategy optimization module, wherein:

[0007] The monitoring module is arranged at the equipment components in the waste heat generator set and the switch cabinet group, and is used to monitor the operating data and environmental data of each equipment component;

[0008] The data acquisition module communicates wirelessly with the monitoring module, and the data acquisition module is used to receive the operation data of each device component in the waste heat generator set and the switch cabinet group monitored by the monitoring module, as well as the parameter information and structure data of the waste heat generator set and the switch cabinet group;

[0009] The data preprocessing module is used to preprocess the acquired operation data, parameter information and structural data before modeling;

[0010] The digital twin management module is used to construct a digital image of the waste heat power generation equipment based on the preprocessed parameter information and structural data, and to drive the simulation of the change of the digital image of the waste heat power generation equipment based on the preprocessed operation data;

[0011] The digital twin management module is pre-set with an element model of the waste heat power generation scenario. The data acquisition module is also used to obtain the scene elements of the scene where the waste heat power generation system is located, and to call the preset element model according to the scene elements to build a digital image of the waste heat power generation scenario, and to drive the change simulation of the digital image of the waste heat power generation scenario according to the environmental data;

[0012] The transmission strategy optimization module is used to use the simulation results of the changes in the digital image of the waste heat power generation equipment and the simulation results of the changes in the digital image of the waste heat power generation scene as the dynamic model of the waste heat power generation system, and to build a power demand prediction model based on the local load power consumption data; the transmission strategy optimization module is also used to call the target optimization algorithm and the power demand prediction model to dynamically adjust the dynamic model of the waste heat power generation system, and generate a waste heat power generation system adjustment command after verifying the dynamic adjustment result, and transmit it to the digital twin management module;

[0013] The digital twin management module is also used to control the digital image of the waste heat power generation equipment to perform simulation evolution according to the waste heat power generation system adjustment command, and to control the operation of the waste heat power generation unit and the switch cabinet group according to the simulation evolution results.

[0014] The principle and advantage of the present invention are as follows: in this scheme, for the effective utilization of steam waste heat, a waste heat generator set and a switch cabinet set are provided, wherein the waste heat generator set is a device for converting waste heat into electric energy, and the switch cabinet set is a device for transmitting the electric energy generated by the waste heat to the local load for power supply, and the switch cabinet set is connected to the city power grid, on the one hand, the waste heat generator set and the city power grid are connected to the grid, and on the other hand, the electric energy generated by the waste heat generator set is isolated from being transmitted to the city power grid, so as to achieve the purpose of not being connected to the grid;

[0015] In the above-mentioned waste heat power generation system that is connected to the grid but not connected to the grid, its power transmission and power consumption optimization are realized through the control system. Specifically, the operation data and environmental data of the waste heat power generation unit and the switch cabinet group are first collected, and the parameter information and structural data of the waste heat power generation unit and the switch cabinet group are obtained at the same time. A digital image of the waste heat power generation equipment is constructed according to the parameter information and structural data, and a digital image of the waste heat power generation scene is constructed according to the environmental data. At the same time, the digital image of the waste heat power generation equipment and the digital image of the waste heat power generation scene are driven to perform change simulation according to the operation data. From the change simulation results, the parameter data of the actual waste heat power generation system used for power consumption optimization can be extracted. In this way, the transmission strategy optimization module is combined with the target optimization algorithm and the power demand prediction model to obtain the optimal transmission strategy to maximize the utilization of steam waste heat.

[0016] Furthermore, the power transmission strategy optimization module includes a power consumption prediction model building unit and a power transmission optimization unit;

[0017] The power consumption prediction model building unit is used to collect the historical power consumption data of the local load and then build a power demand prediction model according to the characteristics in the historical power consumption data. The expression is:

[0018]

[0019] Among them, B is the backshift operator, BP L (k) = P l (k-1), θ(B)=1+θ1B+…+θ q B q ; represents the d-order difference operator, ∈(k) represents the white noise sequence, represents the autoregressive coefficient, θ q represents the moving average coefficient;

[0020] A time window and a power optimization objective function are preset in the power transmission optimization unit. The power transmission optimization unit calls the preset time window to obtain the power demand forecast data output by the power demand forecast model, and after the preset time window is filled, calculates the current power optimization control data of the local load according to the power demand forecast data in the preset time window and the preset power optimization objective function.

[0021] Beneficial effect: By building an electricity demand prediction model, the local load electricity demand can be predicted, and the predicted value is used to calculate the electricity optimization control data based on the electricity optimization objective function. This data is used as the control quantity for subsequent electricity regulation, such as turbine steam inlet regulation, to achieve early control of the regulation control quantity.

[0022] Further, the calculation of the current power consumption optimization control data of the local load according to the power demand forecast data in the preset time window and the preset power consumption optimization objective function is specifically:

[0023] The preset power consumption optimization objective function in the transmission optimization unit is constructed as follows:

[0024]

[0025] Where i = 1, 2, ..., N, N is the prediction time domain, P(k+i|k) is the predicted value of the power generation at the future k+i time based on the current time k, P L (k+i|k) is the predicted value of the local load power consumption at the future k+i time based on the current time k, Δu(k+i) is the control increment at the future k+i time, λ i is the weight coefficient;

[0026] Set constraints, including steam flow constraints, power generation constraints and control increment constraints, and based on each sampling time k, according to the current waste heat power generation system dynamic model state and power demand forecast data, call the preset power optimization objective function to calculate the current power optimization control data and generate a control sequence, the control sequence is: Δu(k), Δu(k+1)…Δu(k+N-1);

[0027] The control sequence is sequentially and rollingly applied to the digital image of the waste heat power generation equipment in the dynamic model of the waste heat power generation system in a time sequence to obtain an optimized control result of the digital image of the waste heat power generation equipment.

[0028] Beneficial effect: Through the above processing steps, the regulation and optimization of the waste heat power generation system is achieved, ensuring the effective use of steam waste heat.

[0029] Furthermore, the waste heat power generation unit includes a steam turbine, a generator, a medium-pressure steam pipeline, a low-pressure steam pipeline, a condenser and a recovery pipeline, the medium-pressure steam pipeline is connected to the main air inlet of the steam turbine, the low-pressure steam pipeline is connected to the auxiliary air inlet of the steam turbine, the steam turbine is connected to the generator through a coupling, and the generator is connected to the switch cabinet group;

[0030] The steam turbine exhaust port is communicated with the condenser inlet, the condenser outlet is communicated with one end of a recovery pipe, and the other end of the recovery pipe is communicated with an external water supply system.

[0031] Beneficial effects: In this scheme, the main function of the waste heat power generation unit is to effectively utilize the boiler steam in the sulfuric acid operation to generate waste heat power. To this end, the generated boiler steam is divided into medium-pressure steam and low-pressure steam according to its gas pressure. The medium-pressure steam is transported to the steam turbine through the medium-pressure steam pipeline. With its high-pressure and high-temperature characteristics, it drives the impeller of the steam turbine to rotate at a high speed, realizing the initial conversion of thermal energy into mechanical energy. At the same time, the low-pressure steam is used as supplementary steam and enters the steam turbine through the low-pressure steam pipeline to optimize the work process of the steam turbine and improve the overall energy conversion efficiency of the waste heat power generation unit.

[0032] At the same time, the exhaust steam after energy conversion in the turbine is output to the condenser, where it is condensed into water through heat exchange with cooling water and recycled to the water supply system to achieve recycling and further improve the energy utilization rate of the entire waste heat power generation unit.

[0033] Furthermore, the switch cabinet group includes a switch cabinet and a cable. The switch cabinet is provided with equipment components for performing electrical isolation, control and protection. The generator in the waste heat power generation group is connected to the incoming line terminal of the switch cabinet through a cable. The switch cabinet is also connected to the municipal power grid through a municipal power interface, and the generator is connected to the grid but not to the grid.

[0034] Beneficial effects: In the switch cabinet assembly, the switch cabinet includes electrical equipment components, which can effectively distribute, control and monitor the electric energy generated by the generator in the waste heat power generation unit, ensuring the safe and stable transmission of electric energy to the local load power grid; at the same time, when the power generation of the waste heat power generation unit is less than the power demand of the local load, the municipal power grid is used to supplement the local load through the switch cabinet to ensure the stable power supply of the local load.

[0035] Furthermore, the digital twin management end includes a device model construction unit, a scene model construction unit, a scene optimization unit and a rendering unit. The device model construction unit is used to construct a digital image of the waste heat power generation equipment according to the parameter information and structural data of each device component in the waste heat power generation unit and the switch cabinet group; the scene model construction unit is used to call the corresponding preset element model to construct a digital image of the waste heat power generation scene according to the environmental data at the waste heat power generation unit and the switch cabinet group; the scene optimization unit is used to associate the digital image of the waste heat power generation equipment with the digital image of the waste heat power generation scene and generate a digital image of the waste heat power generation system. The scene optimization unit is also used to obtain user operation instructions to perform corresponding operations on the digitization of the waste heat power generation system. The rendering unit is used to render the digital image of the waste heat power generation system, and to render the simulation of the change of the digital image of the waste heat power generation system after the user instruction operation.

[0036] Beneficial effects: By constructing a digital image of the waste heat power generation system, the operating status of the waste heat power generation system can be visualized and presented to users in real time, which is convenient for users to understand the operating status of the waste heat power generation system. At the same time, the digital twin technology used can also simulate the aforementioned power optimization plan through a digital image, predict the results of the plan in advance, and facilitate timely detection of errors and corresponding measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a functional block diagram of an embodiment of the present invention;

[0038] Figure 2 Schematic diagram of the structure of a waste heat power generation system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following is further described in detail through specific implementation methods:

[0040] The embodiment is basically as shown in the attached Figure 1 and Figure 2 As shown: A waste heat power generation system that is connected to the grid but not connected to the grid, including a waste heat generator set, a switch cabinet group and a control system. The waste heat generator set is connected to the switch cabinet group. The waste heat generator set is used to convert waste heat into electrical energy and transmit it to the switch cabinet group. The switch cabinet group is used to receive the electrical energy transmitted by the waste heat generator set and transmit it to the local load power grid through distribution processing. The control system is connected to the waste heat generator set and the switch cabinet group. Specifically:

[0041] The waste heat generator set consists of a steam turbine, a generator, a medium-pressure steam pipeline, a low-pressure steam pipeline, a condenser and a recovery pipeline, wherein the steam turbine is connected to the generator through a coupling, so that the rotation of the blades in the steam turbine drives the coupling to rotate, the coupling drives the generator to rotate, the generator generates electricity and transmits it to the switch cabinet; the medium-pressure steam pipeline is connected to the main inlet of the steam turbine, and the low-pressure steam pipeline is connected to the secondary inlet of the steam turbine. In this embodiment, the medium-pressure steam pipeline uses pipes that are resistant to high temperature and high pressure and have good insulation properties, such as alloy steel pipes. The welding of the pipeline meets the process requirements. When the pipeline is installed, a slope of 0.002-0.005 is set to facilitate the smooth flow of medium-pressure steam in the pipeline and prevent condensate from accumulating in the pipeline to cause water hammer. At key locations of the pipeline, such as elbows, tees or valves, temperature and pressure monitoring instruments are installed to grasp the changes in steam parameters in real time; the low-pressure steam pipeline is similar to the above, except that pipes with lower cost and meeting the requirements can be used.

[0042] The condenser inlet is connected to the turbine exhaust port, wherein the installation position of the condenser is lower than the turbine exhaust port so that the exhaust steam in the turbine can flow smoothly into the condenser. The condenser outlet is connected to the recovery pipe, and the condensed water at the condenser outlet flows through the recovery pipe to the external water supply system for recycling.

[0043] Therefore, in the above-mentioned equipment structures of the waste heat power generation unit, the boiler in the sulfuric acid operation area generates medium-pressure steam and low-pressure steam during operation. The standard of medium-pressure steam in this application is 2.5MPa and the temperature is 350°C. The medium-pressure steam enters the main air inlet of the steam turbine through the medium-pressure steam pipeline according to the design flow rate of the steam turbine. The medium-pressure steam expands and does work in the steam turbine, driving the impeller to rotate at high speed, converting the thermal energy of the medium-pressure steam into mechanical energy. At the same time, the steam turbine itself accurately controls the speed through the speed control system, so that the power frequency and output of the generator connected to it are stabilized at a fixed value;

[0044] During the work of the medium-pressure steam in the steam turbine, it is necessary to adjust the amount of low-pressure steam supplement in time, that is, when the steam intake of the steam turbine is insufficient or the steam energy decreases, the low-pressure steam is transported to the steam turbine through the low-pressure steam pipeline. The low-pressure steam used for supplementary steam in this application is maintained at 0.5MPa and the temperature is 200°C. Therefore, the work of the steam turbine in this scheme can improve the energy utilization rate of the steam and keep the output power of the steam turbine stable through the coordinated cooperation of medium-pressure steam and low-pressure steam.

[0045] The switch cabinet group in this embodiment includes a switch cabinet and corresponding cables. In this embodiment, the switch cabinet adopts a KYN28A-12 type switch cabinet. A series of electrical components such as circuit breakers, contactors, relays, inverters, etc. are arranged in the switch cabinet, and the switch cabinet is connected to the generator of the waste heat generator set through cables, so as to realize reasonable distribution and control of electric energy. At the same time, according to the demand of the local load, the switch cabinet can accurately transmit the electric energy to each power-consuming equipment or power-consuming area. In addition, the switch cabinet also has an interface for connecting to the municipal power grid. In this scheme, under normal operation, only the grid-connected but not connected to the municipal power grid function is realized, that is, when the local load power demand is less than the power generation of the waste heat generator set, the excess electric energy of the waste heat generator set will not be transmitted to the municipal power grid, and when the local load power demand is greater than the power generation of the waste heat generator set, the shortfall is supplemented by the municipal power grid to the local load through the switch cabinet to ensure stable power supply to the local load.

[0046] The control system is connected to the waste heat generator set and the switch cabinet group, where the control system includes a monitoring module, a data acquisition module, a data preprocessing module, a digital twin management module and a transmission strategy optimization module. The monitoring module is arranged at the equipment components in the waste heat generator set and the switch cabinet group to monitor the operating data and environmental data of each equipment component; for example, the monitoring module includes various sensors and monitoring cameras, and various sensors are arranged at the equipment components of the waste heat generator set and the switch cabinet group to collect the operating data of each equipment component; at the same time, the monitoring camera collects the environmental data of the waste heat generator set and the switch cabinet group in real time, including real-time video data of the surrounding environment, foreign object detection image data, etc.

[0047] The data acquisition module communicates wirelessly with the monitoring module, wherein the monitoring module transmits the monitored operating data and environmental data to the data acquisition module. In addition to acquiring the operating data and environmental data of the waste heat generator set and the switch cabinet group, the data acquisition module also acquires parameter information and structural data of the waste heat generator set and the switch cabinet group, wherein the waste heat generator set includes a steam turbine, a generator, a medium-pressure steam pipeline, a low-pressure steam pipeline, a condenser and a recovery pipeline, and the switch cabinet group includes a switch cabinet and a cable. By acquiring the parameter information and structural data of the above-mentioned various types of equipment, for example, the parameter information of the steam turbine includes model, specification, rated speed, steam inlet parameters, exhaust parameters, etc., and the structural data includes rotor structure, cylinder structure, bearing type and parameters, steam seal structure, etc., the parameter information and structural data of the above-mentioned various types of equipment are acquired.

[0048] After the operation data, parameter information, and structural data of the waste heat generator set and switch cabinet group are obtained through the data acquisition module, they are preprocessed and analyzed through the data preprocessing module, such as data cleaning, data association, data conversion, etc., so that the preprocessed data can meet the input of the digital twin management module.

[0049] The digital twin management module constructs a digital image of the waste heat power generation equipment based on the pre-processed parameter information and structural data of the waste heat power generation unit and switch cabinet family. In this solution, the generation of the digital image of the waste heat power generation equipment is based on the digital twin technology and uses modeling to restore the real waste heat power generation system; further, the digital twin management module drives the digital image of the waste heat power generation equipment to perform change simulation according to the operation data, so that the operation status of each device in the real waste heat power generation system can be obtained through the digital image of the waste heat power generation equipment, and by adjusting the parameters of the digital image of the waste heat power generation equipment, on the one hand, the simulated operation status of the waste heat power generation equipment after the parameter adjustment can be seen, and the operation on the real waste heat power generation equipment can be performed after the parameters are correct. On the other hand, the digital image of the waste heat power generation equipment can provide real-time feedback to the user on the operation status of each device in the real waste heat power generation system.

[0050] After the waste heat power generation equipment is digitally mirrored and simulated for changes, the digital twin management module also constructs a digital mirror of the waste heat power generation scene based on the environmental data. Specifically, in the digital twin management module, element models of the waste heat power generation scene are preset, such as static objects, including building models, plant models, etc., and dynamic objects, including people and animals, where people include men, women, children, etc., and animals include snakes, mice, and floating or moving foreign objects, such as plastic bags, kites, etc.; in this way, when constructing a digital mirror of the waste heat power generation scene, the monitoring module monitors the characteristics of the objects in the environment where the waste heat generator set and the switch cabinet set are located, and the corresponding scene model is quickly retrieved according to the characteristics, so that the digital mirror of the waste heat power generation scene is quickly constructed, saving computing resources and high model change efficiency, and the required configuration is low; similarly, according to the operating data of the waste heat power generation equipment scene, or the user input instruction requirements, the scene model in the digital mirror of the waste heat power generation scene is increased or decreased in real time to achieve the purpose of rapid transformation, and the transformation process is realized by the rendering unit in the digital twin management module.

[0051] In the digital image generated by the above-mentioned digital twin management module, the operation status of the waste heat power generation system can be reflected in real time according to the results of the change simulation. In this regard, in order to improve the high utilization rate of steam waste heat in the waste heat power generation system, it is necessary to improve and optimize the transmission strategy of the waste heat power generation system. Therefore, in this scheme, the simulation results of the change of the digital image of the waste heat power generation equipment and the simulation results of the change of the digital image of the waste heat power generation scene are used as the dynamic model of the waste heat power generation system. The dynamic model can reflect in real time the relationship between the medium-pressure steam flow, the low-pressure steam flow and the power generation of the waste heat generator set in the waste heat power generation system, and can also reflect the relationship between the power generation and power consumption of the waste heat generator set and the local load of the switch cabinet combination. In this regard, the operation data obtained from the simulation results of the change of the digital image can be represented as the operation data of the real waste heat power generation system.

[0052] The power transmission strategy optimization module includes a power consumption forecasting model building unit and a power transmission optimization unit. The power consumption forecasting model building unit builds a power demand forecasting model based on the local load power consumption data. In this scheme, the construction process of the power demand forecasting model is as follows: it is necessary to collect the historical data of the local load, including the power demand change curve over time and the load fluctuation law in different time periods. For this, the autoregressive moving average model is used in this scheme to build a power demand forecasting model to predict the future power demand of the local load. The expression is:

[0053]

[0054] Among them, B is the backshift operator, BP L (k) = P L (k-1), θ(B)=1+θ1B+…+θ q B q ; represents the d-order difference operator, ∈(k) represents the white noise sequence, represents the autoregressive coefficient, θ q Represents the moving average coefficient; in the specific implementation, taking the autoregressive moving average model ARIMA (d=1, p=1, q=1) as an example, for the sequence after the first-order difference The expression of the electricity demand forecasting model is:

[0055]

[0056] in, is the autoregressive coefficient, θ1 is the moving average coefficient, ∈(k) is the white noise sequence;

[0057] Then the least squares method is used to estimate and the value of θ1;

[0058] Finally, the load demand P at time k+1 is predicted L (k+1), according to the actual k value, the load demand at time k+1 can be obtained.

[0059] After the electricity demand forecasting model building unit builds the electricity demand forecasting model, it outputs the electricity demand forecasting data, which is input into the power transmission optimization unit, wherein the power transmission optimization unit presets the time window and the electricity optimization objective function, and the power transmission optimization unit calls the forecast time window to obtain the electricity demand forecasting data output by the electricity demand forecasting model. For example, if the preset time window is 3 days, all the electricity demand forecasting data of the electricity demand forecasting model in the next 3 days are input into the preset time window as the initial data. Then, after the preset time window is filled, the power transmission optimization unit calculates the current electricity optimization control data of the local load according to the electricity demand forecasting data in the preset time window and the preset electricity optimization objective function. Specifically, the calculation process is:

[0060] Step 1: Construct the preset power consumption optimization objective function in the transmission optimization unit as follows:

[0061]

[0062] Where i = 1, 2, ..., N, N is the prediction time domain, P(k+i|k) is the predicted value of the power generation at the future k+i time based on the current time k, P L (k+i|k) is the predicted value of the local load power consumption at the future k+i time based on the current time k, Δu(k+i) is the control increment at the future k+i time, λ i is the weight coefficient;

[0063] Step 2: Set constraints, including steam flow constraints, power generation constraints and control increment constraints, and based on each sampling time k, according to the current waste heat power generation system dynamic model state and power demand forecast data, call the preset power optimization objective function to calculate the current power optimization control data and generate a control sequence, the control sequence is: Δu(k), Δu(k+1)…Δu(k+N-1);

[0064] Step 3: The control sequence is sequentially applied to the digital image of the waste heat power generation equipment in the dynamic model of the waste heat power generation system in a rolling manner according to the time sequence to obtain the optimized control result of the digital image of the waste heat power generation equipment.

[0065] Therefore, in this scheme, based on the simulation of changes in the digital image of the waste heat power generation equipment in the generated waste heat power generation system and the simulation of changes in the digital image of the waste heat power generation scene, the control strategy of the entire system is optimized, which greatly improves the utilization rate of steam waste heat in the waste heat power generation system in this scheme.

[0066] The above are only embodiments of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. Ordinary technicians in the relevant field know all the common technical knowledge in the technical field to which the invention belongs before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A waste heat power generation system that is connected to the grid but not connected to the grid, characterized in that: It includes a waste heat generator set, a switch cabinet group and a control system. The waste heat generator set is connected to the switch cabinet group. The waste heat generator set is used to convert waste heat into electrical energy and transmit it to the switch cabinet group. The switch cabinet group is used to receive the electrical energy transmitted by the waste heat generator set and transmit it to the local load power grid through distribution processing. The control system is connected to the waste heat generator set and the switch cabinet group. The control system includes a monitoring module, a data acquisition module, a data preprocessing module, a digital twin management module and a transmission strategy optimization module, wherein: The monitoring module is arranged at the equipment components in the waste heat generator set and the switch cabinet group, and is used to monitor the operating data and environmental data of each equipment component; The data acquisition module communicates wirelessly with the monitoring module, and the data acquisition module is used to receive the operation data of each device component in the waste heat generator set and the switch cabinet group monitored by the monitoring module, as well as the parameter information and structure data of the waste heat generator set and the switch cabinet group; The data preprocessing module is used to preprocess the acquired operation data, parameter information and structural data before modeling; The digital twin management module is used to construct a digital image of the waste heat power generation equipment based on the preprocessed parameter information and structural data, and to drive the simulation of the change of the digital image of the waste heat power generation equipment based on the preprocessed operation data; The digital twin management module is pre-set with an element model of the waste heat power generation scenario. The data acquisition module is also used to obtain the scene elements of the scene where the waste heat power generation system is located, and to call the preset element model according to the scene elements to build a digital image of the waste heat power generation scenario, and to drive the change simulation of the digital image of the waste heat power generation scenario according to the environmental data; The transmission strategy optimization module is used to use the simulation results of the changes in the digital image of the waste heat power generation equipment and the simulation results of the changes in the digital image of the waste heat power generation scene as the dynamic model of the waste heat power generation system, and to build a power demand prediction model based on the local load power consumption data; the transmission strategy optimization module is also used to call the target optimization algorithm and the power demand prediction model to dynamically adjust the dynamic model of the waste heat power generation system, and generate a waste heat power generation system adjustment command after verifying the dynamic adjustment result, and transmit it to the digital twin management module; The digital twin management module is also used to control the digital image of the waste heat power generation equipment to perform simulation evolution according to the waste heat power generation system adjustment command, and to control the operation of the waste heat power generation unit and the switch cabinet group according to the simulation evolution results.

2. A waste heat power generation system connected to the grid but not connected to the grid according to claim 1, characterized in that: The power transmission strategy optimization module includes a power consumption prediction model building unit and a power transmission optimization unit; The power consumption prediction model building unit is used to collect the historical power consumption data of the local load and then build a power demand prediction model according to the characteristics in the historical power consumption data. The expression is: Among them, B is the backshift operator, BP L (k) = P l (k-1), θ(B)=1+θ1B+…+θ q B q ; represents the d-order difference operator, ∈(k) represents the white noise sequence, represents the autoregressive coefficient, θ q represents the moving average coefficient; A time window and a power optimization objective function are preset in the power transmission optimization unit. The power transmission optimization unit calls the preset time window to obtain the power demand forecast data output by the power demand forecast model, and after the preset time window is filled, calculates the current power optimization control data of the local load according to the power demand forecast data in the preset time window and the preset power optimization objective function.

3. A waste heat power generation system connected to the grid but not connected to the grid according to claim 2, characterized in that: The calculation of the current power consumption optimization control data of the local load according to the power demand forecast data in the preset time window and the preset power consumption optimization objective function is specifically: The preset power consumption optimization objective function in the power transmission optimization unit is constructed as follows: Where i = 1, 2, ..., N, N is the prediction time domain, P(k+i|k) is the predicted value of the power generation at the future k+i time based on the current time k, P L (k+i|k) is the predicted value of the local load power consumption at the future k+i time based on the current time k, Δu(k+i) is the control increment at the future k+i time, λ i is the weight coefficient; Set constraints, including steam flow constraints, power generation constraints and control increment constraints, and based on each sampling time k, according to the current waste heat power generation system dynamic model state and power demand forecast data, call the preset power optimization objective function to calculate the current power optimization control data and generate a control sequence, the control sequence is: Δu(k), Δu(k+1)…Δu(k+N-1); The control sequence is sequentially and rollingly applied to the digital image of the waste heat power generation equipment in the dynamic model of the waste heat power generation system in a time sequence to obtain an optimized control result of the digital image of the waste heat power generation equipment.

4. The waste heat power generation system for connecting to the grid but not connected to the grid according to claim 3 is characterized by: The waste heat power generation unit includes a steam turbine, a generator, a medium-pressure steam pipeline, a low-pressure steam pipeline, a condenser and a recovery pipeline, wherein the medium-pressure steam pipeline is connected to the main air inlet of the steam turbine, the low-pressure steam pipeline is connected to the auxiliary air inlet of the steam turbine, the steam turbine is connected to the generator through a coupling, and the generator is connected to the switch cabinet group; The steam turbine exhaust port is communicated with the condenser inlet, the condenser outlet is communicated with one end of a recovery pipe, and the other end of the recovery pipe is communicated with an external water supply system.

5. A waste heat power generation system connected to the grid but not connected to the grid according to claim 4, characterized in that: The switch cabinet group includes a switch cabinet and a cable. The switch cabinet is provided with equipment components for performing electrical isolation, control and protection. The generator in the waste heat power generation group is connected to the incoming line terminal of the switch cabinet through a cable. The switch cabinet is also connected to the municipal power grid through a municipal power interface, and the generator is connected to the grid but not to the grid.

6. A waste heat power generation system for connecting to the grid but not connected to the grid according to claim 5, characterized in that: The digital twin management end includes a device model construction unit, a scene model construction unit, a scene optimization unit and a rendering unit. The device model construction unit is used to construct a digital image of the waste heat power generation equipment according to the parameter information and structural data of each device component in the waste heat power generation unit and the switch cabinet group; The scene model building unit is used to call the corresponding preset element model to build a digital image of the waste heat power generation scene according to the environmental data of the waste heat power generation group and the switch cabinet group; The scene optimization unit is used to associate the digital image of the waste heat power generation equipment with the digital image of the waste heat power generation scene and generate a digital image of the waste heat power generation system. The scene optimization unit is also used to obtain user operation instructions to perform corresponding operations on the digitization of the waste heat power generation system. The rendering unit is used to render the digital image of the waste heat power generation system, and to render the simulation of the change of the digital image of the waste heat power generation system after the user instruction operation.

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