Urea chemical system comprehensive energy scheduling method and system considering multi-energy-mass coupling

Abstract

The invention belongs to the related technical field of electrical engineering, and discloses a urea chemical system comprehensive energy scheduling method and system considering multi-energy-mass coupling, and the method comprises the steps: constructing an operation model of each device in a system, the device comprises a water electrolysis hydrogen production device, a pressure swing adsorption device, a biomass gasification hydrogen production device, an electrochemical energy storage device, a hydrogen-doped gas turbine, a carbon capture device, a synthesis ammonia device and a urea synthesis device. Building balance constraints among the devices in the system, wherein the balance constraints comprise electric balance constraints, heat balance constraints, oxygen balance constraints, hydrogen balance constraints and carbon dioxide balance constraints; constructing a cost function; and solving the model by taking the minimum cost function as an optimization target to obtain an optimal scheduling scheme. The energy utilization rate of the rural chemical industrial park can be effectively improved, the carbon emission intensity is reduced, and the cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field related to electrical engineering, and more particularly, to a urea chemical system comprehensive energy scheduling method and system considering multi-energy coupling. BACKGROUND

[0002] Rural areas have abundant wind energy, solar energy, biomass energy and other renewable energy sources, but there are problems such as low energy efficiency, insufficient utilization, and unreasonable planning and configuration. With a large number of chemical enterprises gradually moving from cities to rural areas, coal-fired and gas turbine-based chemical production entering rural areas will cause serious environmental pollution, and it is urgent to reform the rural energy utilization structure and build a high-energy efficiency, low-carbon emission and low-cost rural chemical system. SUMMARY

[0003] In view of the above defects or improvement needs of the prior art, the present application provides a urea chemical system comprehensive energy scheduling method and system considering multi-energy coupling, which aims to effectively improve the energy utilization rate of rural chemical industrial parks, reduce carbon emission intensity and reduce costs.

[0004] To achieve the above-mentioned purpose, according to the first aspect of the present application, a urea chemical system comprehensive energy scheduling method considering multi-energy coupling is provided, which comprises:

[0005] A running model of each device in the system is constructed, the devices including a water electrolysis hydrogen production device, a pressure swing adsorption device, a biomass gasification hydrogen production device, an electrochemical energy storage device, a hydrogen-doped gas turbine, a carbon capture device, an ammonia synthesis device and a urea synthesis device; the water electrolysis hydrogen production device produces hydrogen and oxygen by electrolyzing water; the pressure swing adsorption device separates nitrogen and oxygen in air by selective adsorption based on carbon molecular sieve using air as raw material, producing nitrogen and oxygen; the biomass gasification hydrogen production device produces hydrogen and carbon dioxide by reacting biomass with oxygen and separates the gas by chemical looping method; the electrochemical energy storage device realizes electrochemical energy storage charging and discharging, but charging and discharging cannot be performed at the same time; the hydrogen-doped gas turbine produces electric energy and carbon dioxide by adding hydrogen as a fuel source in addition to natural gas; the carbon capture device captures the carbon dioxide produced by the hydrogen-doped gas turbine; the ammonia synthesis device produces ammonia by synthesizing hydrogen and nitrogen; and the urea synthesis device synthesizes urea using ammonia and carbon dioxide.

[0006] Construct balance constraints between various devices in the system, and the balance constraints include electrical balance constraints, thermal balance constraints, oxygen balance constraints, hydrogen balance constraints, and carbon dioxide balance constraints; wherein, the oxygen balance constraint indicates that the oxygen produced by the device is balanced with the oxygen required by the device and the oxygen sold, the oxygen produced by the device includes the sum of oxygen from the water electrolysis hydrogen production device and the pressure swing adsorption device, and the oxygen required by the device includes the input oxygen of the biomass gasification hydrogen production device; the hydrogen balance constraint indicates that the hydrogen produced by the device is balanced with the hydrogen required by the device, the hydrogen produced by the device includes the sum of hydrogen from the water electrolysis hydrogen production device and the biomass gasification hydrogen production device, and the hydrogen required by the device includes the hydrogen consumed by the hydrogen-blended gas turbine and the ammonia synthesis device; the carbon dioxide balance constraint indicates that the sum of carbon dioxide produced by the device and purchased carbon dioxide is balanced with the carbon dioxide required by the device, the carbon dioxide produced by the device includes the sum of carbon dioxide from the biomass gasification hydrogen production device and the carbon capture device, and the carbon dioxide required by the device includes the carbon dioxide consumed by the urea synthesis device;

[0007] Constructing a cost function, the cost function comprising expenditure costs minus revenue, the expenditure costs comprising the purchase costs of biomass, natural gas, and carbon dioxide, the operation and maintenance costs of the system devices, and the system power curtailment penalty costs, and the revenue comprising revenue from the sale of oxygen;

[0008] The model is solved with the optimization goal of minimizing the cost function to obtain the optimal scheduling solution.

[0009] According to a second aspect of the present invention, there is provided an integrated energy scheduling system for a urea chemical system taking into account multi-energy coupling, comprising a memory and a processor, wherein the memory stores a computer program, wherein the processor implements the steps of the above method when executing the computer program.

[0010] According to a third aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0011] According to a fourth aspect of the present invention, there is provided a computer program product comprising a computer program or instructions, which implement the steps of the above method when executed by a processor.

[0012] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0013] The present invention can reduce carbon emissions: Because the present invention modifies the gas turbine and uses both natural gas and hydrogen as fuel, it can improve the low-carbon content of the gas turbine's fuel source. Furthermore, the introduction of a carbon capture device to capture carbon dioxide and use it as a raw material for urea synthesis reduces carbon dioxide emissions into the air. The lower the carbon content of the fuel source, the less carbon dioxide is emitted into the air.

[0014] The present invention can reduce system costs: in order to reduce carbon emissions, the carbon content of the gas turbine is reduced, and the carbon capture device may be underpowered, resulting in insufficient captured carbon dioxide to synthesize the required amount of urea. In this case, the present invention is combined with a biomass gasification hydrogen production device. The biomass gasification hydrogen production device reacts biomass with oxygen to produce hydrogen and carbon dioxide, wherein the carbon dioxide is also used as a raw material for synthesizing urea, thereby reducing the purchase cost of carbon dioxide when synthesizing urea; moreover, the pressure swing adsorption device in the present invention collects oxygen while collecting nitrogen. The oxygen produced by the pressure swing adsorption device and the water electrolysis hydrogen production device can be directly used in the biomass gasification hydrogen production device. The biomass gasification hydrogen production device does not need to purchase oxygen, and the remaining oxygen in the system can be sold to increase revenue. Therefore, the system cost can be further reduced.

[0015] The present invention can improve energy efficiency: the present invention sets electrical balance constraints and thermal balance constraints. The electrical energy and thermal energy generated within the system can be provided to the internal devices, forming a supply and demand balance and improving energy efficiency.

[0016] In general, the present invention effectively improves the energy utilization rate of rural chemical parks, reduces carbon emission intensity and reduces costs by performing multi-energy coupling. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flowchart of the steps of a comprehensive energy scheduling method for a urea chemical system considering multi-energy coupling in one embodiment of the present invention;

[0018] Figure 2 It is a wind and solar power output per unit curve and an electricity and heat load demand curve in the integrated energy dispatch of the urea chemical system in one embodiment of the present invention;

[0019] Figure 3 This is a thermal energy balance diagram in the integrated energy scheduling of a urea chemical system in one embodiment of the present invention;

[0020] Figure 4 This is an electric energy balance diagram in the integrated energy scheduling of a urea chemical system in one embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0022] Example 1

[0023] The present invention discloses a comprehensive energy scheduling method for a urea chemical system considering multi-energy coupling, such as Figure 1 The figure shows a flowchart of the steps of a comprehensive energy scheduling method for a urea chemical system considering multi-energy coupling in one embodiment of the present invention, and the steps are introduced below.

[0024] S1. Construct the operation model of each device in the system, including water electrolysis hydrogen production device, pressure swing adsorption device, biomass gasification hydrogen production device, electrochemical energy storage device, hydrogen-blended gas turbine, ammonia synthesis device, carbon capture device and urea synthesis device.

[0025] Before building the operation model of each device, it is necessary to obtain rural wind and solar load data and the inherent parameters of each device.

[0026] Among them, rural wind and solar load data include the daily wind power output curve, the daily photovoltaic power output curve, as well as the daily electricity load demand curve, the daily heat load demand curve, and the daily urea load demand curve in rural areas.

[0027] In the present invention, the inputs and outputs of the various devices in the system are tightly coupled to achieve efficient utilization of substances such as electrical energy, thermal energy, hydrogen, oxygen and carbon dioxide.

[0028] The following is an introduction to each device.

[0029] 1) Water electrolysis hydrogen production device.

[0030] Water electrolysis hydrogen production devices produce hydrogen and oxygen through the electrolysis of water. They feature a wide operating current density range, rapid start-up and shutdown, and flexible power regulation. They are highly adaptable to fluctuating and intermittent power sources and can be easily integrated with renewable energy sources such as wind and solar power.

[0031] Construct an operation model of the water electrolysis hydrogen production device, including: constructing the power consumption of the electrolyzer The operating current provided by the electrolyzer The relationship between the electrolytic cell heat recovery power and power consumption The relationship between the power consumption of the electrolytic cell is and the ramping power of the electrolyzer at the adjacent time is subjected to upper and lower limit constraints, t is time, is the to-be-optimized variable.

[0032] Specifically, the operation model of the water electrolysis hydrogen production device can be expressed in the following form:

[0033]

[0034] wherein, is the power consumption of the electrolyzer at time t, N cell is the number of electrolysis chambers; is the operating voltage and current of the electrolyzer at time t; U rev is the reversible voltage; is the ohmic overvoltage at time t; is the activation overpotential at time t; are the partial pressures of hydrogen and oxygen, respectively; is the activity of water; R cell is the internal equivalent ohmic resistance; is the current density at time t; F is the Faraday coefficient; α an , α cat are the partial pressures of hydrogen and oxygen, respectively; i an , i cat are the anode and cathode current densities, respectively; A cell is the effective reaction area; is the hydrogen production efficiency of the electrolyzer at time t; is the hydrogen heat value; is the heat recovery power of the electrolyzer at time t; η pem,h is the heat recovery efficiency; h F is the Faraday efficiency; are the hydrogen production rate and oxygen production rate of the water electrolysis hydrogen production device at time t, respectively; P pem,min , P pem,max are the minimum and maximum operating powers of the electrolyzer; ΔP pem,up , ΔP pem,down are the upper and lower limits of the electrolyzer ramping; unit conversion coefficients k1=0.001 (W→kW), k3=3600 (kW→kJ / h), k2=RT / P, T and P are the standard temperature and pressure, respectively, and R is the gas constant.

[0035] 2) Pressure swing adsorption device.

[0036] The pressure swing adsorption device separates nitrogen and oxygen in air by selective adsorption based on carbon molecular sieve using air as raw material, and produces nitrogen and oxygen.

[0037] An operation model of the pressure swing adsorption device is constructed, including: constructing the power consumption of the pressure swing adsorption device and oxygen production rate Nitrogen production rate The relationship between the power consumption of the pressure swing adsorption device Perform upper and lower limit constraints, t is time, is the variable to be optimized.

[0038] Specifically, the operation model of the pressure swing adsorption device can be expressed as follows:

[0039]

[0040] Where, is the power consumption of the pressure swing adsorption device at time t; is the air processing rate at time t; η m is the mechanical efficiency of the device; η PSA,ise is the isentropic efficiency; T PSA is the operating temperature of the pressure swing adsorption device; R is the universal gas constant; P out 、P in is the outlet and inlet pressure of the pressure swing adsorption device; ρ air is the air mass density; are the air input rate, oxygen output rate, and nitrogen output rate of the pressure swing adsorption device at time t; is the percentage of oxygen and nitrogen in the air; P PSA,max 、P PSA,min It is the maximum and minimum operating power of the pressure swing adsorption device.

[0041] 3) Biomass gasification hydrogen production equipment.

[0042] The biomass gasification hydrogen production device reacts biomass with oxygen from water electrolysis and pressure swing adsorption devices to produce hydrogen and carbon dioxide and separate the gases using a chemical chain method.

[0043] Specifically, biomass gasification to produce hydrogen is the process of converting biomass particles into hydrogen-containing combustible gas in a gasifying agent. High-purity hydrogen and enriched CO2 can then be separated through a chemical chain method. The hydrogen production from gasification in oxygen is significantly higher than that in air.

[0044] Construct an operation model of a biomass gasification hydrogen production device, including: constructing the feed rate of a biomass gasification hydrogen production device Oxygen input rate Hydrogen production rate and carbon dioxide production rate The relationship between the power consumption of biomass gasification hydrogen production device and hydrogen production rate The relationship between the two, and the heat recovery power of the biomass gasification hydrogen production device With feed rate The relationship between the feed rate And the upper and lower limits of the feed ramp rate at adjacent moments are constrained, t is the time, is the variable to be optimized.

[0045] Specifically, the operation model of the biomass gasification hydrogen production device can be expressed as follows:

[0046]

[0047]

[0048] Where, are the feed rate, oxygen input rate, hydrogen production rate, and carbon dioxide production rate of the biomass gasification unit at time t; is the reaction coefficient of biomass gasification oxygen, hydrogen, carbon dioxide and biomass; is the power consumption of the biomass gasification hydrogen production device at time t; σ bio The electrical energy consumption required to produce unit hydrogen for the biomass gasification unit; is the heat recovery power of the biomass gasification hydrogen production device at time t; η bio,h is the heat recovery efficiency of the biomass gasification device; L bio is the calorific value of biomass; N bio,max 、N bio,min are the upper and lower limits of the feed rate of the biomass gasification device; ΔN bio,up , ΔN bio,down They are the upper and lower limits of the feed ramp rate of the biomass gasification unit respectively.

[0049] 4) Electrochemical energy storage device.

[0050] The electrochemical energy storage device realizes electrochemical energy storage charging and discharging and cannot be charged and discharged at the same time.

[0051] Constructing an operating model of an electrochemical energy storage device, including: constructing the storage capacity of electrochemical energy storage and the charging power of electrochemical energy storage Discharge power The relationship between the stored power Charging power Discharge power Perform upper and lower limit constraints, t is time, is the variable to be optimized.

[0052] Specifically, the operation model of the electrochemical energy storage device can be expressed as follows:

[0053]

[0054] Where, is the charging and discharging power of electrochemical energy storage at time t; P is the charge and discharge state variable of the electrochemical energy storage at time t, which is used to ensure that the electrochemical energy storage cannot be charged and discharged at the same time; bat,max is the maximum charge and discharge power of electrochemical energy storage; is the amount of electrochemical energy stored at time t, are the electrochemical energy storage capacity at the start and end of the scheduling period. If the scheduling period is one day, it means that the initial and final states of the energy storage within one day must be balanced; σ bat is the self-consumption rate of electrochemical energy storage; η bat E is the charge and discharge efficiency of electrochemical energy storage; bat,max 、E bat,min It is the upper and lower limits of the amount of electricity that can be stored in electrochemical energy storage.

[0055] 5) Hydrogen-blended gas turbine.

[0056] The hydrogen-blended gas turbine produces electricity and carbon dioxide by adding hydrogen from a water electrolysis hydrogen production device and a biomass gasification hydrogen production device as a fuel source on the basis of natural gas.

[0057] In the present invention, in order to improve the low carbon level of the fuel source of the gas turbine and flexibly utilize hydrogen energy, a gas turbine hydrogen blending device is introduced.

[0058] Constructing an operating model of a hydrogen-blended gas turbine, including: constructing the combustion power release of the gas turbine and gas turbine natural gas consumption rate Hydrogen consumption rate The relationship between and natural gas consumption rate and the rate of carbon dioxide release The relationship between the power generation capacity of the gas turbine and the and combustion release power The relationship between the heat recovery power of the gas turbine and combustion release power The relationship between the hydrogen blending ratio and the combustion release power And the upper and lower limits of the combustion release climbing power at adjacent moments are constrained, t is the time, is the variable to be optimized.

[0059] Specifically, the operating model of the hydrogen-blended gas turbine can be expressed as follows:

[0060]

[0061]

[0062] Where, is the power released by gas turbine combustion at time t; is the natural gas consumption, hydrogen consumption, and carbon dioxide release rate of the gas turbine at time t; are the calorific values ​​of natural gas and hydrogen respectively; is the reaction coefficient of gas turbine carbon dioxide and natural gas; is the gas turbine power generation and heat recovery power at time t; η GU,e ,η GU,h is the electricity and heat conversion efficiency of the gas turbine; α GU,max , α GU,min is the upper and lower limits of hydrogen doping ratio; Q GU,max , Q GU,min The upper and lower limits of the gas turbine combustion power release; ΔQ GU,up , ΔQ GU,down It is the upper and lower limits of the gas turbine climbing power.

[0063] 6) Carbon capture device.

[0064] The carbon capture device captures the carbon dioxide produced by the hydrogen-blended gas turbine. The introduction of carbon capture equipment captures the carbon dioxide produced by the gas turbine and uses it as a feedstock for the urea production unit, reducing carbon purchase costs and lowering carbon emissions.

[0065] Constructing an operating model of the carbon capture device, including: constructing the total power of the carbon capture device and operating energy consumption Fixed energy consumption P CCS,f The relationship between the carbon capture device and the rate of carbon dioxide capture The rate of carbon dioxide release from hydrogen-blended gas turbines and the rate of carbon dioxide diversion to air The relationship between the two, and the operating energy consumption and the rate of carbon dioxide capture The relationship between the two, and the operating energy consumption The upper and lower limits of the ramp power of the carbon capture device at adjacent moments are constrained, t is the time, is the variable to be optimized.

[0066] Specifically, the operation model of the carbon capture device can be expressed as follows:

[0067]

[0068]

[0069] Where, P CCS,f is the total power, operating energy consumption, and fixed energy consumption of the carbon capture device at time t; e cEnergy consumption required for capturing unit carbon dioxide; Carbon dioxide rate captured by carbon capture device at time t, released by gas turbine, and shunted to air; Carbon capture efficiency; P CCS,max Maximum operating power of carbon capture device; ΔP CCS,up , ΔP CCS,down Upper and lower limits of ramping power of carbon capture device.

[0070] 7) Synthetic ammonia device.

[0071] The synthetic ammonia device produces ammonia gas by synthesizing hydrogen gas from the electrolytic water hydrogen production device and the biomass gasification hydrogen production device and nitrogen gas from the pressure swing adsorption device. Hydrogen gas and nitrogen gas are introduced into the synthetic ammonia device to produce ammonia gas using the Haber-Bosch method.

[0072] An operating model of the synthetic ammonia device is constructed, including: constructing a relationship between ammonia gas production rate and nitrogen gas consumption rate , hydrogen gas consumption rate , and constructing a relationship between power consumption of the synthetic ammonia device and ammonia gas production rate , and heat recovery power of the synthetic ammonia device and ammonia gas production rate , and constraining the power consumption and the ramping power of the synthetic ammonia device at the adjacent time t, t being time, is a variable to be optimized.

[0073] Specifically, the operating model of the synthetic ammonia device can be expressed in the following form:

[0074]

[0075]

[0076] In the formula, is the power consumption of the synthetic ammonia device at time t; is the electrical energy consumption required by the synthetic ammonia device to produce unit ammonia gas; is the ammonia gas production rate, nitrogen gas consumption rate, and hydrogen gas consumption rate of the synthetic ammonia device at time t; is the reaction coefficient of nitrogen gas, hydrogen gas, and ammonia gas of the synthetic ammonia device; is the heat recovery power of the synthetic ammonia device; η HB,h is the efficiency of the heat recovery device; σ HB is the heat released by producing unit ammonia gas; P HB,max , P HB,minThe upper and lower limits of the operating power of the synthetic ammonia unit; ΔP HB,up , ΔP HB,down The upper and lower limits of the operating power ramp of the synthetic ammonia unit.

[0077] 8) Urea synthesis equipment.

[0078] The urea synthesis unit uses ammonia from the ammonia synthesis unit and carbon dioxide from the biomass gasification hydrogen production unit and carbon capture unit to synthesize urea.

[0079] Urea, as the main raw material for fertilizer, an important agricultural product in rural areas, has a wide application market in rural areas. The main raw materials for synthetic urea are ammonia and carbon dioxide.

[0080] Constructing the operation model of the synthetic urea device, including: constructing the power consumption of the synthetic urea device and CO2 consumption rate The relationship between the production rate of urea and and ammonia consumption rate Carbon dioxide consumption rate The relationship between the power consumption The upper and lower limits of the climbing power of the urea synthesis device at adjacent moments are set, and t is the time.

[0081] Specifically, the operation model of the synthetic urea unit can be expressed as follows:

[0082]

[0083] Where, is the power consumption of the urea synthesis device at time t; The electrical energy consumption per unit of carbon dioxide consumed when synthesizing urea; are the urea production rate, ammonia consumption rate, and carbon dioxide consumption rate of the urea synthesis unit at time t; is the reaction coefficient of ammonia, carbon dioxide and urea in the urea synthesis unit; P UR,max 、P UR,min The upper and lower limits of the operating power of the synthetic urea unit; ΔP UR,up , ΔP UR,down It is the upper and lower limits of the operating power ramp of the synthetic urea unit.

[0084] Based on the above method, an operation model of each device in the system is constructed.

[0085] S2. Construct balance constraints between various devices in the system. The balance constraints include electrical balance constraints, thermal balance constraints, oxygen balance constraints, hydrogen balance constraints, and carbon dioxide balance constraints.

[0086] In the present invention, the inputs and outputs of the various devices in the system are tightly coupled, and waste heat from the operation of the water electrolysis hydrogen production, biomass gasification hydrogen production, and ammonia synthesis units in the chemical system is recycled and utilized to supply heat load; oxygen, a by-product of the water electrolysis and pressure swing adsorption (PSA) unit, is supplied to the biomass gasification hydrogen production, and excess oxygen is sold for profit; the CO2 required for the urea synthesis unit comes from the exhaust gas of the biomass gasification hydrogen production unit and the hydrogen-doped gas turbine; and the hydrogen-doped gas turbine can broaden the application paths of hydrogen in the system.

[0087] The power balance constraint indicates that the total power generation of the system device is balanced with the total power consumption of the system device, where the total power generation of the system device includes the wind power generation power. Photovoltaic power generation Hydrogen-blended gas turbine power generation and the discharge power of the electrochemical energy storage device The total power consumption of the system device includes the power demand of the electrical load Power consumption of electrolyzer in water electrolysis hydrogen production device Charging power of electrochemical energy storage devices Power consumption of pressure swing adsorption device Power consumption of ammonia synthesis plant And the power consumption of the urea synthesis device The sum of .

[0088] The electrical balance constraint can be specifically expressed as:

[0089]

[0090] Where, are wind power and photovoltaic power generation at time t, which are variables to be optimized. is the power demand of the electric load at time t.

[0091] The heat balance constraint indicates that the total heat recovery power of the system device is balanced with the heat demand of the system heat load, where the total heat recovery power of the system device includes the heat recovery power of the hydrogen-blended gas turbine. Heat recovery power of electrolyzer in water electrolysis hydrogen production device Heat recovery power of ammonia synthesis unit Heat recovery power of biomass gasification hydrogen production device The sum of .

[0092] The thermal balance constraint can be specifically expressed as:

[0093]

[0094] Where, is the heat demand of the heat load at time t.

[0095] The oxygen balance constraint indicates that the oxygen produced by the system device is balanced with the oxygen required by the system device and the oxygen sold. The oxygen produced by the system device includes the oxygen production rate of the water electrolysis hydrogen production device. and the oxygen production rate of the pressure swing adsorption device The sum of the oxygen required by the system device includes the oxygen input rate of the biomass gasification hydrogen production device

[0096] The oxygen balance constraint can be specifically expressed as:

[0097]

[0098] Where, is the amount of oxygen sold at time t.

[0099] The hydrogen balance constraint indicates that the hydrogen produced by the system device is balanced with the hydrogen required by the system device, where the hydrogen produced by the system device includes the hydrogen production efficiency of the electrolyzer in the water electrolysis hydrogen production device. and the hydrogen production rate of the biomass gasification hydrogen production device The sum of the hydrogen required by the system and the hydrogen consumption rate of the hydrogen-blended gas turbine and the hydrogen consumption rate of the ammonia synthesis unit

[0100] The hydrogen balance constraint can be specifically expressed as:

[0101]

[0102] The CO2 balance constraint indicates that the sum of the CO2 produced by the system and the purchased CO2 is balanced with the CO2 required by the system. The CO2 produced by the system includes the CO2 production rate of the biomass gasification hydrogen production unit. and the CO2 rate of the carbon capture device The sum of the carbon dioxide required by the system devices, including the carbon dioxide consumption rate of the urea synthesis device

[0103] CO2 balance constraint:

[0104]

[0105] Where, is the CO2 purchased by the system at time t.

[0106] Based on the above method, the balance constraints between various devices in the system are constructed.

[0107] S3. Construct a cost function. The cost function includes expenditure costs minus revenue. The expenditure costs include the purchase costs of biomass, natural gas, and carbon dioxide, the operation and maintenance costs of the system equipment, and the penalty costs for system power curtailment. The revenue includes the revenue from selling oxygen.

[0108] Specifically, the cost function can be expressed as:

[0109]

[0110] Where C is the daily operating cost of the system, C bio For the cost of purchasing biomass, The cost of purchasing natural gas, The cost of purchasing carbon dioxide, C R is the system equipment operation and maintenance cost, C q Penalty cost for system power curtailment, For the proceeds from the sale of oxygen.

[0111] S4. Solve the model with the optimization goal of minimizing the cost function to obtain the optimal scheduling solution.

[0112] Specifically, the optimization objective can be expressed as min C. The model is solved by the solver, and the output variables to be optimized are shown in Table 1 below.

[0113] Table 1

[0114]

[0115]

[0116] Example 2

[0117] The present invention also relates to an integrated energy scheduling system for a urea chemical system taking into account multi-energy coupling, comprising a memory and a processor, wherein the memory stores a computer program and the processor implements the steps of the above method when executing the computer program.

[0118] The system can be installed on computing devices such as desktop computers, notebooks, PDAs and cloud servers. The processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The memory can be used to store computer programs and / or modules, and the processor can run or execute computer programs and / or modules stored in the memory, as well as call data stored in the memory, to realize various functions of the electronic device.

[0119] Example 3

[0120] The present invention also relates to a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above method when the computer program is executed by a processor.

[0121] Specifically, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0122] Example 4

[0123] An embodiment of the present invention provides a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the steps of the method of the above embodiment of the present invention.

[0124] Example 5

[0125] In this example, wind power and photovoltaic power are used as the energy sources of this system. The output curve refers to the historical wind power and photovoltaic power generation output per unit data of a village in Henan Province. The electricity and heat load data refer to the actual annual load output per unit curve of the village. A typical day is selected as the wind power, photovoltaic, and load daily power curve. The sampling time is 1 hour interval, that is, the power is considered to be unchanged in each interval, and the value is equivalent to the value at the beginning of the interval. The power curve is as follows:Figure 2 shown.

[0126] Urea industrial production requires stable operation, so this example sets the power of the synthetic urea unit to a constant value, that is, to ensure a stable supply of urea products.

[0127] The construction capacity of each equipment in the rural urea chemical system model is shown in Table 2 below:

[0128] Table 2

[0129]

[0130] The commercial software Gurobi 10.0.3 is used to solve the model constructed in the present invention to obtain the optimal scheduling solution. Figure 3 The thermal energy curve in the scheduling results is shown, and the rural chemical system can maintain thermal energy conservation in each time period. Figure 4 The power conservation curve in the scheduling results is shown. The rural chemical system can maintain power conservation in every time period.

[0131] Table 3 below shows the simulation results parameters of the rural urea chemical system with and without considering multi-energy coupling:

[0132] Table 3

[0133]

[0134] As shown in Table 3, the proposed multi-energy-mass coupling system can effectively improve the system operation economy through energy-mass coupling while ensuring the smooth operation of the system to meet the load demand. Compared with the system without energy-mass coupling, the total system operation cost is reduced by 54.73%, the carbon emission intensity is reduced by 87.45%, and the new energy consumption rate is increased by 24.64%.

[0135] The technical features of the above embodiments can be combined in any manner. To simplify the description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. It should be noted that the phrases "in one embodiment", "for example", "and another example", etc. of the present invention are intended to illustrate the present invention and are not intended to limit the present invention.

[0136] The above embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A comprehensive energy scheduling method for a urea chemical system considering multi-energy coupling, characterized in that: include: Construct an operation model for each device in the system, including a water electrolysis hydrogen production device, a pressure swing adsorption device, a biomass gasification hydrogen production device, an electrochemical energy storage device, a hydrogen-blended gas turbine, a carbon capture device, an ammonia synthesis device, and a urea synthesis device; the water electrolysis hydrogen production device produces hydrogen and oxygen by electrolyzing water; the pressure swing adsorption device uses air as a raw material and selectively adsorbs carbon molecular sieves to separate nitrogen and oxygen in the air to produce nitrogen and oxygen; the biomass gasification hydrogen production device reacts biomass with oxygen to produce hydrogen and carbon dioxide and uses a chemical chaining method to separate the gases; the electrochemical energy storage device realizes electrochemical energy storage charging and discharging, and charging and discharging cannot be performed simultaneously at the same time; the hydrogen-blended gas turbine adds hydrogen as a fuel source to natural gas to produce electricity and carbon dioxide; the carbon capture device captures carbon dioxide produced by the hydrogen-blended gas turbine; the ammonia synthesis device produces ammonia by synthesizing hydrogen and nitrogen; and the urea synthesis device synthesizes urea from ammonia and carbon dioxide. Construct balance constraints between various devices in the system, and the balance constraints include electrical balance constraints, thermal balance constraints, oxygen balance constraints, hydrogen balance constraints, and carbon dioxide balance constraints; wherein, the oxygen balance constraint indicates that the oxygen produced by the device is balanced with the oxygen required by the device and the oxygen sold, the oxygen produced by the device includes the sum of oxygen from the water electrolysis hydrogen production device and the pressure swing adsorption device, and the oxygen required by the device includes the input oxygen of the biomass gasification hydrogen production device; the hydrogen balance constraint indicates that the hydrogen produced by the device is balanced with the hydrogen required by the device, the hydrogen produced by the device includes the sum of hydrogen from the water electrolysis hydrogen production device and the biomass gasification hydrogen production device, and the hydrogen required by the device includes the hydrogen consumed by the hydrogen-blended gas turbine and the ammonia synthesis device; the carbon dioxide balance constraint indicates that the sum of carbon dioxide produced by the device and purchased carbon dioxide is balanced with the carbon dioxide required by the device, the carbon dioxide produced by the device includes the sum of carbon dioxide from the biomass gasification hydrogen production device and the carbon capture device, and the carbon dioxide required by the device includes the carbon dioxide consumed by the urea synthesis device; Constructing a cost function, the cost function comprising expenditure costs minus revenue, the expenditure costs comprising the purchase costs of biomass, natural gas, and carbon dioxide, the operation and maintenance costs of the system devices, and the system power curtailment penalty costs, and the revenue comprising revenue from the sale of oxygen; The model is solved with the optimization goal of minimizing the cost function to obtain the optimal scheduling solution.

2. The scheduling method according to claim 1, wherein: Constructing the operation model of the water electrolysis hydrogen production device, including: constructing the power consumption of the electrolyzer The operating current provided by the electrolyzer The relationship between the electrolytic cell heat recovery power and power consumption The relationship between the power consumption of the electrolytic cell is And the upper and lower limits of the climbing power of the electrolyzer at adjacent moments are constrained, t is the time, is the variable to be optimized.

3. The scheduling method according to claim 1, wherein: Constructing the operation model of the biomass gasification hydrogen production device, including: constructing the feed rate of the biomass gasification hydrogen production device Oxygen input rate Hydrogen production rate and carbon dioxide production rate The relationship between the power consumption of the biomass gasification hydrogen production device and the power consumption of the biomass gasification hydrogen production device and hydrogen production rate and the heat recovery power of the biomass gasification hydrogen production device. With feed rate The relationship between the feed rate And the upper and lower limits of the feed ramp rate at adjacent moments are constrained, t is the time, is the variable to be optimized.

4. The scheduling method according to claim 3, wherein: The operation model of the biomass gasification hydrogen production device is: Where, are the feed rate, oxygen input rate, hydrogen production rate, and carbon dioxide production rate of the biomass gasification unit at time t; is the reaction coefficient of biomass gasification oxygen, hydrogen, carbon dioxide and biomass; is the power consumption of the biomass gasification hydrogen production device at time t; σ bio The electrical energy consumption required to produce unit hydrogen for the biomass gasification unit; is the heat recovery power of the biomass gasification hydrogen production device at time t; η bio,h is the heat recovery efficiency of the biomass gasification device; L bio is the calorific value of biomass; N bio,max 、N bio,min are the upper and lower limits of the feed rate of the biomass gasification device; ΔN bio,up , ΔN bio,down They are the upper and lower limits of the feed ramp rate of the biomass gasification unit respectively.

5. The scheduling method according to claim 1, wherein: Constructing the operation model of the hydrogen-blended gas turbine, including: constructing the combustion release power of the gas turbine and gas turbine natural gas consumption rate Hydrogen consumption rate The relationship between and natural gas consumption rate and the rate of carbon dioxide release The relationship between the power generation capacity of the gas turbine and the and combustion release power The relationship between the heat recovery power of the gas turbine and combustion release power The relationship between the hydrogen blending ratio and the combustion release power And the upper and lower limits of the combustion release climbing power at adjacent moments are constrained, t is the time, is the variable to be optimized.

6. The scheduling method according to claim 5, wherein: The operation model of the hydrogen-blended gas turbine is: Where, is the power released by gas turbine combustion at time t; is the natural gas consumption, hydrogen consumption, and carbon dioxide release rate of the gas turbine at time t; are the calorific values ​​of natural gas and hydrogen respectively; is the reaction coefficient of gas turbine carbon dioxide and natural gas; is the gas turbine electrical power and heat recovery power at time t; η GU,e ,η GU,h is the electricity and heat conversion efficiency of the gas turbine; α GU,max , α GU,min is the upper and lower limits of hydrogen doping ratio; Q GU,max , Q GU,min Release power upper and lower limits for gas turbine combustion; ΔQ GU,up , ΔQ GU,down It is the upper and lower limits of the gas turbine climbing power.

7. The scheduling method according to claim 1, wherein: The electrical balance constraint indicates that the total power generation power of the device is balanced with the total power consumption power of the device, wherein the total power generation power of the device includes the sum of the power generation power of wind and solar power, the hydrogen-blended gas turbine and the electrochemical energy storage device, and the total power consumption power of the device includes the sum of the required power of the electric load, the power consumption of the water electrolysis hydrogen production device, the electrochemical energy storage device, the pressure swing adsorption device, the ammonia synthesis device and the urea synthesis device; the thermal balance constraint indicates that the total heat recovery power of the device is balanced with the required heat of the system heat load, wherein the total heat recovery power of the device includes the sum of the heat recovery power of the hydrogen-blended gas turbine, the water electrolysis hydrogen production device, the ammonia synthesis device and the biomass gasification hydrogen production device.

8. A comprehensive energy scheduling system for a urea chemical system considering multi-energy coupling, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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