Energy-saving and carbon-reducing optimal control method and system for power plant

Abstract

The invention discloses an energy-saving and carbon-reducing optimization control method and system for a power plant. The system comprises a multi-medium fuel gas regulation and control module, a fuel dynamic adaptation module, a fuel gas supply optimization module, a low-carbon power generation module, a waste heat recycling module, a whole-plant fuel gas balance module, a fuel gas collection and supply module, an energy storage peak regulation module and a fuel gas safety diffusion module. The method comprises the following steps: acquiring output and consumption data of blast furnace gas, converter gas and coke oven gas of a target industrial plant area, judging a fuel gas balance state, dynamically optimizing a fuel gas consumption path and replacing high-calorific-value fuel gas when the fuel gas balance state is unbalanced, determining a fuel gas supply scheme of a generator set, regulating and controlling operation parameters, and adjusting a fuel ratio and a fuel consumption. According to the invention, surplus industrial fuel gas can be effectively consumed, fuel gas diffusion and energy waste are reduced, the effective components of the fuel gas are fully utilized to improve the energy utilization efficiency, the solid fuel consumption and the CO emission are reduced, and the win-win situation of energy conservation, carbon reduction and economic benefit of a power plant is realized.

Description

Technical Field

[0001] This invention relates to the fields of energy conservation and carbon reduction technology in power plants and environmental protection technology, and in particular to an optimized control method and system for energy conservation and carbon reduction in power plants. Background Technology

[0002] Industrial enterprises generate large amounts of by-product gas during smelting processes such as coking, blast furnace ironmaking, and converter steelmaking, including coke oven gas, blast furnace gas, and converter gas. To reduce energy waste and improve energy utilization efficiency, some of this gas is currently supplied to power plants for electricity generation. However, traditional power generation methods suffer from low gas utilization efficiency and supply-demand imbalances.

[0003] When industrial plant production loads fluctuate or power plant equipment is under maintenance, the gas balance is easily disrupted, and surplus gas is often directly released, resulting in energy waste and environmental pollution. Furthermore, green and low-carbon development is the main theme of today's energy industry. Traditional power generation methods only focus on the thermal energy utilization of gas, neglecting the optimal configuration of gas composition, leading to high carbon emission intensity, which does not meet the requirements of low-carbon development. Therefore, how to achieve a dynamic balance between gas supply and demand, improve gas utilization efficiency, and reduce carbon emissions are urgent problems that power plants need to solve. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide an energy-saving and carbon-reducing optimization control method and system for power plants, which can solve the technical problems of energy waste and high carbon emissions in the prior art.

[0005] To achieve the above and other related objectives, this invention provides an energy-saving and carbon-reducing optimization control system for power plants, comprising: a multi-media gas regulation module for calculating and regulating the operating parameters of a target generator set after gas supply; wherein the target generator set includes a low-carbon energy-saving generator set; a fuel dynamic adaptation module for dynamically adjusting the fuel ratio and fuel consumption of the target generator set according to the operating parameters; a gas supply optimization module for determining the supply scheme of the target generator set according to the expected gas type and quantity; a low-carbon power generation module for generating electricity and consuming a portion of surplus gas according to the supply scheme, the operating parameters, the fuel ratio, and the fuel consumption; a waste heat recovery and utilization module for recovering waste heat generated during generator set operation to provide heat energy for auxiliary equipment in the plant area or convert it into additional electricity; a plant-wide gas balance module for dynamically allocating the surplus gas to achieve dynamic balance; and a gas collection and supply module for providing the surplus gas; wherein the surplus gas includes blast furnace gas, converter gas, and coke oven gas from the target industrial plant area.

[0006] Optionally, the system further includes an energy storage and peak-shaving module, used to store surplus electrical energy other than the low-carbon power generation module, waste heat recovery and utilization module and gas collection and supply module, and release electrical energy during peak electricity consumption periods to improve energy utilization efficiency.

[0007] Optionally, the system further includes a gas safety venting module, used to safely burn and vent the excess gas when the energy storage peak-shaving module cannot completely absorb the remaining gas.

[0008] Optionally, the gas supply optimization module includes at least one of the following: blast furnace gas purification supply unit, converter gas treatment supply unit, and coke oven gas adaptation supply unit.

[0009] Optionally, the blast furnace gas purification and supply unit includes at least one of the following: gas dust removal device, gas desulfurization device, gas pressurization device, gas decarbonization device, gas heating device, and gas transmission device.

[0010] Optionally, the coke oven gas adaptation supply unit includes at least one of the following: a gas purification device, a gas pressurization device, a gas transmission device, and a gas composition adjustment device.

[0011] Optionally, the converter gas treatment and supply unit includes at least one of the following: a gas pressurization device, a gas decarbonization device, a gas filtration device, and a gas transmission device.

[0012] This invention also provides an energy-saving and carbon-reducing optimization control method for power plants. The method includes the following steps: acquiring the types of natural gas in the target industrial plant area and the corresponding output and consumption data for each type of natural gas; wherein, the types of natural gas include: blast furnace gas, converter gas, and coke oven gas; determining whether the natural gas supply and demand of the target industrial plant area is balanced based on the types of natural gas and the corresponding output and consumption data for each type of natural gas; if balanced, maintaining the current operating state and outputting natural gas balance information; if unbalanced, dynamically optimizing and adjusting the natural gas consumption path and replacing it with high-calorific-value natural gas for use by the target generator set; acquiring the types and quantities of natural gas expected to be used by the target generator set, and adjusting the natural gas supply and demand data according to the target generator set's requirements. The gas supply scheme for the target generator set is determined by the type and quantity of gas expected to be used by the unit; the operating parameters of the target generator set after gas supply are calculated and controlled, and the fuel ratio and fuel consumption of the target generator set are dynamically adjusted according to the operating parameters; some surplus gas is consumed according to the supply scheme, the operating parameters, the fuel ratio, and the fuel consumption; and waste heat generated during the operation of the generator set is recovered to achieve secondary energy utilization; power generation data and surplus gas information are output, and the types of gas in the target industrial plant area and the corresponding output and consumption data of each type of gas are iteratively obtained to achieve a dynamic balance between gas and electricity supply in the target industrial plant area.

[0013] Optionally, the process of calculating and regulating the operating parameters of the target generator set after gas supply includes: when the target generator set uses coke oven gas, controlling the H2 / (CO+H2) ratio in the gas to be between 15% and 20%; and when the target generator set uses converter gas, controlling the gas supply to be between 50 and 125 m³ / MWh, and controlling the calorific value of the gas to be greater than or equal to 6000 kJ / m³.

[0014] Optionally, the process of dynamically adjusting the fuel ratio and fuel consumption of the target generator set according to the operating parameters includes: combining the operating parameters with the energy balance and emission control model of the target generator set to dynamically adjust the fuel ratio and fuel consumption of the target generator set; wherein, the operating parameters include the type and supply of natural gas. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the hardware structure of a power plant energy-saving and carbon-reducing optimization control system provided in one embodiment of the present invention; Figure 2 This is a schematic diagram of the hardware structure of a gas supply optimization module provided in one embodiment of the present invention; Figure 3 This is a flowchart illustrating an energy-saving and carbon-reducing optimization control method for power plants, as provided in one embodiment of the present invention. Detailed Implementation

[0016] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0017] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0018] This embodiment provides an energy-saving and carbon-reducing optimization control system for power plants, including: a multi-media gas regulation module, a fuel dynamic adaptation module, a gas supply optimization module, a low-carbon power generation module, a waste heat recovery and utilization module, a plant-wide gas balance module, a gas collection and supply module, an energy storage and peak-shaving module, and a gas safety release module.

[0019] Among them, in addition to being used for power generation, the low-carbon power generation module can also consume the surplus gas in the industrial plant area and adjust the gas supply-demand balance; the raw fuel dynamic adaptation module dynamically adjusts the fuel ratio and consumption of the generator set according to the optimized calculation results of the multi-medium gas regulation module; the multi-medium gas regulation module calculates and regulates the key operating parameters after the gas supply of the generator set, guides the stable and efficient operation of the unit, and reduces carbon emissions; the gas supply optimization module processes the surplus gas, including purification, decarbonization, pressurization, etc., to ensure the stable supply of gas to the generator set; the waste heat recovery and utilization module recovers the waste heat during the operation of the unit to achieve secondary utilization of energy; the whole-plant gas balance module dynamically distributes gas, optimizes the consumption path, and reduces gas flaring; the gas collection and supply module is responsible for collecting various by-product gases in the industrial plant area; the energy storage and peak regulation module stores the surplus electric energy to alleviate the peak-valley difference of electricity consumption; the gas safety flaring module performs safety flaring when the gas is excessive.

[0020] In an exemplary embodiment, the gas supply optimization module includes a blast furnace gas purification and supply unit, a converter gas treatment and supply unit, and a coke oven gas adaptation and supply unit. The blast furnace gas purification and supply unit includes a gas dust removal device, a gas desulfurization device, a gas pressurization device, a gas decarbonization device, a gas heating device, and a gas transmission device; the coke oven gas adaptation and supply unit includes a gas purification device, a gas pressurization device, a gas transmission device, and a gas composition adjustment device; the converter gas treatment and supply unit includes a gas pressurization device, a gas decarbonization device, a gas filtration device, and a gas transmission device.

[0021] This embodiment also provides a method for optimizing the energy conservation and carbon reduction control of a power plant. Taking the power plant supporting an industrial plant area as an example, the implementation process is elaborated in detail: First, collect the gas production and consumption data of the industrial plant area, which involves three types of gas: blast furnace gas, converter gas, and coke oven gas. The power plant supporting this plant area has 4 low-carbon generator sets with a capacity of 1 million kilowatts each. When operating normally, there is a surplus of 1,087,220 m³ / h of gas (converted to blast furnace gas) in the whole plant, and all the surplus gas is used for power generation. The load rate of the generators is 93%, and there is no gas flaring in the whole plant.

[0022] Judge the gas income and expenditure situation of the whole plant. If there is an imbalance between supply and demand or equipment maintenance leads to incomplete consumption of gas, enter the whole-plant gas balance module for regulation. When a certain generator set is under maintenance (the maintenance cycle is 46 days) and only 3 generator sets are operating, calculated at 2.93 m³ of blast furnace gas generating 1 kWh of electricity, about 208,220 m³ of gas per hour is at risk of flaring. Through the optimization and adjustment of the whole-plant gas balance module, 31,200 m³ of coke oven gas in the coking process is replaced with 247,470 m³ of blast furnace gas with the same calorific value. On the premise of ensuring the normal operation of 3 generator sets, 25,000 m³ of coke oven gas and 40,000 m³ of converter gas are replaced for use by the low-carbon generator sets.

[0023] It outputs the types, quantities, and composition parameters of surplus gas available for generator sets, including 25,000 Nm³ / h of coke oven gas with CO accounting for 7.8% and H2 accounting for 63.3%; and 40,000 Nm³ / h of converter gas with CO accounting for 45.5% and CO2 accounting for 18.8%.

[0024] The gas supply scheme is determined to be a mixed supply of coke oven gas and converter gas. The two types of gas are purified, pressurized, and decarbonized by the corresponding processing unit of the gas supply optimization module before being delivered to the generator set.

[0025] The optimal operating parameters are determined by the multi-media gas control module, the mixed gas supply is controlled at 70~90 m³ / MWH, and the H2 / (H2+CO) ratio is controlled at around 15.7%.

[0026] By utilizing the dynamic fuel adaptation module and combining it with the energy balance and emission control model of the generator set, the raw fuel consumption indicators were determined, including 342 kg / t of coke and 120 kg / t of pulverized coal. The main economic and technical indicators show that, compared with the baseline scheme, the fuel ratio decreased from 500 kg / t to 462 kg / t, the carbon reduction rate reached 7.5%, and the CO2 emission reduction was 114 kg / MWh.

[0027] During the operation of the generator set, the waste heat recovery module recovers waste heat from flue gas and cooling waste heat to provide thermal energy for heating in the plant area and auxiliary equipment. The remaining electrical energy is stored through the energy storage and peak shaving module.

[0028] It outputs power generation data and remaining gas information, and iteratively feeds them back to the gas balance module to continuously maintain a dynamic balance between gas and electricity supply.

[0029] The method and system of this embodiment reduce energy waste caused by gas venting, avoiding economic losses of approximately RMB 51 million during power plant maintenance alone. Meanwhile, waste heat recovery and energy storage peak shaving further improve energy utilization. On the other hand, by optimizing the use of gas, solid fuel consumption and CO2 emissions are reduced, reducing CO2 emissions by approximately 340,000 tons per year, achieving a win-win situation of energy conservation, carbon reduction, and economic benefits for power plants.

Claims

1. A power plant energy saving and carbon reduction optimization control system, characterized in that, Including: A multi-medium gas control module is used to calculate and control the operating parameters of the target generator set after gas supply; wherein, the target generator set includes a low-carbon energy-saving generator set. A dynamic fuel adaptation module is used to dynamically adjust the fuel ratio and fuel consumption of the target generator set according to the operating parameters. The gas supply optimization module is used to determine the supply scheme of the target generator set based on the type and quantity of gas expected to be used by the target generator set. A low-carbon power generation module is used to generate electricity and consume a portion of surplus gas according to the supply scheme, the operating parameters, the fuel ratio, and the fuel consumption. The waste heat recovery module is used to recover the waste heat generated during the operation of the generator set, and to provide thermal energy for the auxiliary equipment in the plant area or convert it into additional electrical energy. The plant-wide gas balance module is used to dynamically allocate the surplus gas so that the surplus gas can achieve dynamic balance. A gas collection and supply module is used to provide the surplus gas; wherein the surplus gas includes blast furnace gas, converter gas and coke oven gas from the target industrial plant area.

2. The power plant energy saving and carbon reduction optimization control system according to claim 1, characterized in that, The system also includes an energy storage and peak shaving module, which stores the surplus electrical energy outside of the low-carbon power generation module, waste heat recovery and utilization module and gas collection and supply module, and releases the electrical energy during peak electricity consumption periods to improve energy utilization efficiency.

3. The power plant energy-saving and carbon-reduction optimization control system according to claim 2, characterized in that, The system also includes a gas safety venting module, which is used to safely burn and vent the excess gas when the energy storage and peak shaving module cannot completely absorb the remaining gas.

4. The power plant energy-saving and carbon-reduction optimization control system according to claim 1, characterized in that, The gas supply optimization module includes at least one of the following: blast furnace gas purification supply unit, converter gas treatment supply unit, and coke oven gas adaptation supply unit.

5. The power plant energy-saving and carbon-reduction optimization control system according to claim 4, characterized in that, The blast furnace gas purification and supply unit includes at least one of the following: gas dust removal device, gas desulfurization device, gas pressurization device, gas decarbonization device, gas heating device, and gas transmission device.

6. The power plant energy-saving and carbon-reducing optimization control system according to claim 4, characterized in that, The coke oven gas adaptation and supply unit includes at least one of the following: a gas purification device, a gas pressurization device, a gas transmission device, and a gas composition adjustment device.

7. The power plant energy-saving and carbon-reduction optimization control system according to claim 4, characterized in that, The converter gas treatment and supply unit includes at least one of the following: a gas pressurization device, a gas decarbonization device, a gas filtration device, and a gas transmission device.

8. A method for optimizing energy conservation and carbon reduction control in power plants, characterized in that, The method includes the following steps: Acquire the types of natural gas used in the target industrial plant and the corresponding output and consumption data for each type of natural gas; wherein, the types of natural gas include: blast furnace gas, converter gas and coke oven gas; Based on the type of gas and the corresponding output and consumption data for each type of gas, determine whether the gas supply and demand of the target industrial plant is balanced; if balanced, maintain the current operating status and output gas balance information; if unbalanced, dynamically optimize and adjust the gas consumption path and replace it with high-calorific-value gas for use by the target generator set. Obtain the type and quantity of gas expected to be used by the target generator set, and determine the gas supply plan for the target generator set based on the type and quantity of gas expected to be used by the target generator set; Calculate and regulate the operating parameters of the target generator set after gas supply, and dynamically adjust the fuel ratio and fuel consumption of the target generator set according to the operating parameters; Based on the supply plan, the operating parameters, the fuel ratio, and the fuel consumption, a portion of the surplus gas is consumed; and waste heat generated during the operation of the generator set is recovered to achieve secondary energy utilization. Output power generation data and remaining gas information, and iteratively obtain the types of gas in the target industrial plant area and the corresponding output and consumption data of each type of gas, so as to achieve a dynamic balance between gas and electricity supply in the target industrial plant area.

9. The power plant energy-saving and carbon-reduction optimization control method according to claim 8, characterized in that, The process of calculating and regulating the operating parameters of the target generator set after gas supply includes: When the target generator set uses coke oven gas, the H2 / (CO+H2) ratio in the gas should be controlled between 15% and 20%. Furthermore, when the target generator set uses converter gas, the gas supply is controlled between 50 and 125 m³ / MWh, and the calorific value of the gas is controlled to be greater than or equal to 6000 kJ / m³.

10. The power plant energy-saving and carbon-reduction optimization control method according to claim 8, characterized in that, The process of dynamically adjusting the fuel ratio and fuel consumption of the target generator set according to the operating parameters includes: combining the operating parameters with the energy balance and emission control model of the target generator set to dynamically adjust the fuel ratio and fuel consumption of the target generator set; wherein, the operating parameters include the type and supply of natural gas.

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