CN-122026444-A - Off-grid wind-light-hydrogen-ammonia integrated system and scheduling method

CN122026444ACN 122026444 ACN122026444 ACN 122026444ACN-122026444-A

Abstract

The invention discloses an off-grid wind-light-hydrogen-ammonia integrated system and a scheduling method, and relates to the technical field of renewable energy sources. The method comprises the steps of calculating the relative error between the wind-solar actual power generation and the predicted power generation after each rolling scheduling period is finished, triggering a deviation correction flow if the relative error exceeds a preset threshold, and otherwise, keeping the original plan. When the energy is corrected, the energy deviation is calculated by combining the dispatching plan and the actual output force, and bidirectional graded regulation and control are implemented according to the direction of the energy deviation, wherein the energy deviation is used for preferentially storing hydrogen and recharging energy when the energy is surplus, and the energy deviation is used for preferentially discharging and recharging hydrogen when the energy is shortage. The actual state of hydrogen storage and energy storage is dynamically updated according to the method and is used as the initial condition of the next period. According to the method, through a threshold triggering and grading response mechanism, the power discarding and energy gaps are effectively reduced, continuous and stable operation of the ammonia synthesis device is ensured, and meanwhile, the system robustness and the green electricity utilization efficiency are remarkably improved.

Inventors

LI DANDAN
WEI XIANAN
ZHAO HONGPENG
WANG YUEXIN
YANG XIUYU
LI ZHEN
YANG CHENG

Assignees

中国电力工程顾问集团东北电力设计院有限公司
东北电力大学

Dates

Publication Date: 20260512
Application Date: 20260210

Claims (7)

1. The off-grid wind, light, hydrogen and ammonia integrated system is characterized by comprising an electric energy storage device, an electric hydrolysis device, a purification device, a hydrogen storage tank, air separation equipment, a synthetic ammonia tower and an ammonia separation device; The electric energy storage device is used for receiving and storing wind-solar electric energy; the electric hydrolysis device comprises a plurality of electrolytic tanks connected in parallel, receives wind, light and electric energy, performs chemical reaction with water to prepare hydrogen, processes the hydrogen through the purification device, and stores the hydrogen in the hydrogen storage tank; the air separation equipment is used for receiving wind, light and electric energy and separating nitrogen from air; and synthesizing the hydrogen and the nitrogen into ammonia gas by the ammonia synthesizing tower, and sending the ammonia gas into an ammonia separating device for ammonia separation to obtain liquid ammonia.
2. The dispatching method of the off-grid wind, light, hydrogen and ammonia integrated system is characterized by comprising the following steps of: After each rolling scheduling period is finished, calculating a relative prediction error according to the actual total power generation amount and the predicted total power generation amount of the wind power system; If the relative prediction error is larger than a preset error threshold, triggering a deviation correction flow, otherwise, continuing to use the original plan; After triggering a deviation correction flow, calculating energy deviation according to the rolling scheduling plan parameters and combining the actual total power generation amount and the predicted total power generation amount of the wind power system; And carrying out bidirectional grading correction according to the energy deviation direction to obtain the initial condition of the next rolling scheduling period.
3. The scheduling method of claim 2, wherein the relative prediction error is expressed as: In the formula, A relative prediction error for a kth scheduling period; The actual total power generation amount of the kth period; the predicted total power generation amount for the kth period.
4. The scheduling method of claim 2, wherein the error threshold is 10%.
5. The scheduling method according to claim 2, wherein calculating the energy deviation based on the rolling schedule parameters in combination with the actual total power generation and the predicted total power generation of the wind power system includes: according to the actual total power generation amount and the rolling scheduling plan parameters, calculating the actual residual power, wherein the expression is as follows: In the formula, Is the actual residual electric quantity; Is the actual total power generation; the total electricity consumption of the ammonia synthesizing tower is the kth period; the total power consumption of the hydrogen production device in the kth period; The load of the ammonia tower is synthesized for the kth period; hydrogen production power for the kth cycle hydrogen production device; the duration of the scheduling period for scrolling; According to the predicted total power generation amount and the rolling scheduling plan parameters, calculating the predicted residual power, wherein the expression is as follows: In the formula, To predict the remaining power; To predict the total power generation; According to the actual residual electric quantity and the predicted residual electric quantity, calculating energy deviation, wherein the expression is as follows: In the formula, Is the energy deviation.
6. The scheduling method according to claim 2, wherein the performing bidirectional hierarchical correction according to the energy deviation direction to obtain the initial condition of the next rolling scheduling period includes: if the energy deviates The method adopts the priority order of storing hydrogen and then storing energy for correction, and comprises the following steps: according to the running state of the hydrogen storage tank, calculating the hydrogen storage capacity, and updating the hydrogen storage state, wherein the expression is as follows: In the formula, Is the hydrogen storage capacity; is the energy deviation; rated gas quantity for the hydrogen storage tank; the actual hydrogen mass at the end of the k period of the hydrogen storage tank; The energy conversion coefficient; is the rated power of the electro-hydrolysis device; the operating power of the k period of the electro-hydrolysis device; the duration of the scheduling period for scrolling; The updated actual hydrogen quality; if the hydrogen storable electric quantity is larger than the energy deviation, finishing correction, otherwise, calculating the residual energy, wherein the expression is as follows: In the formula, Is the remaining energy; Energy deviation; according to the residual energy, calculating the actual charge quantity of the electric energy storage device, and updating the energy storage state, wherein the expression is as follows: In the formula, Is the actual charge amount; is the rated capacity of the electric energy storage device; actual capacity at the end of the K period; The updated actual capacity; and calculating the electric quantity abandoned amount according to the electric quantity capable of storing hydrogen and the actual charging quantity, wherein the expression is as follows: In the formula, The actual power loss for the k scheduling periods.
7. The scheduling method according to claim 2, wherein the performing bidirectional hierarchical correction according to the energy deviation direction to obtain the initial condition of the next rolling scheduling period includes: If it is The method adopts the priority order of discharging before releasing hydrogen for correction, and comprises the following steps: according to the running state of the electric energy storage device, calculating the releasable energy storage electric quantity and updating the energy storage state, wherein the expression is as follows: In the formula, Is capable of releasing energy storage electric quantity; is the energy deviation; The actual capacity of the electric energy storage device at the end of the k period; The updated actual capacity; if the releasable energy storage electric quantity is larger than the energy deviation, finishing correction, otherwise, calculating the residual deviation energy, wherein the expression is as follows: In the formula, Is the residual deviation energy; according to the residual deviation energy, calculating the equivalent hydrogen storage electric quantity, and updating the hydrogen storage state, wherein the expression is as follows: In the formula, Is the equivalent electric quantity of hydrogen storage; the actual hydrogen mass at the end of the k period of the hydrogen storage tank; The energy conversion coefficient; According to the releasable energy storage electric quantity and the hydrogen storage equivalent electric quantity, calculating notch energy, wherein the expression is as follows: In the formula, Is notch energy; If it is And generating an energy shortage early warning.

Description

Off-grid wind-light-hydrogen-ammonia integrated system and scheduling method Technical Field The invention relates to the technical field of renewable energy sources, in particular to an off-grid wind-light-hydrogen-ammonia integrated system and a scheduling method. Background Currently, off-grid renewable energy hydrogen production ammonia synthesis systems generally employ a predictive-based rolling optimization scheduling method or a rule-based energy management strategy. The typical operation mechanism is that when each dispatching rolling period starts, a reference operation plan in the period is formulated according to the predicted data of wind-light output and load demand in a future period, and the reference operation plan comprises power setting of the electrolytic water hydrogen production device, charging and discharging strategies of an energy storage/hydrogen storage system, operation gears of the synthetic ammonia device and the like. However, in actual engineering operation, renewable energy output has significant randomness and volatility, and a deviation between a predicted value and an actual output is unavoidable. Such "planned-execution" inconsistencies can cause two typical problems, namely, when the actual output is higher than the predicted value, the system generates surplus power exceeding the plan, if the energy storage (such as a battery) or the hydrogen storage capacity is close to the upper limit, the surplus energy cannot be effectively absorbed, so that the waste wind and the light are abandoned, and when the actual output is lower than the predicted value, the system is insufficient in energy supply, and the load of the electrolytic tank or the synthetic ammonia device is forced to drop due to energy supply interruption, and even the non-planned shutdown is caused. The above problems are particularly acute for off-grid ammonia synthesis systems. Because of the lack of the power supporting and adjusting capability of the external power grid, any energy supply and demand unbalance is difficult to buffer through external interaction, and the deviation effect is easily amplified, so that the overall energy balance stability of the system is threatened, and the operation state of key equipment is possibly out of limit (such as hydrogen storage pressure overrun, battery SoC overrun and the like). More importantly, the ammonia plant is highly sensitive to operational continuity and operating stability. The unplanned load adjustment, frequent start-stop or large power fluctuation not only can remarkably reduce the ammonia synthesis efficiency, but also can cause severe changes of a reactor temperature field and a reactor pressure field, exacerbate the thermal stress and mechanical fatigue of equipment, shorten the service life of the device and possibly bring potential safety hazards. The existing scheduling control method generally depends on a mode of generating an operation plan at the beginning of a rolling period, and lacks a real-time monitoring, quantitative evaluation and dynamic response mechanism for prediction deviation in the rolling period. Once the plan is formulated, even if significant deviation occurs, the original plan can be only passively executed, or local protection logic triggered by a simple threshold value is relied on, and on the premise that the safety boundary of the system is difficult to be ensured, dynamic coupling relations among energy storage SoC (State of Charge), hydrogen storage SoG (State of Gas), flexible regulation capacity of the electrolytic tank and synthetic ammonia load are actively coordinated, so that the effective inhibition of deviation influence and on-line correction of the running track are realized. Disclosure of Invention The invention aims to provide an off-grid wind-light-hydrogen-ammonia integrated system and a scheduling method, and aims to solve or improve at least one of the technical problems. In order to achieve the above object, the present invention provides the following solutions: The off-grid wind, light, hydrogen and ammonia integrated system comprises an electric energy storage device, an electric hydrolysis device, a purification device, a hydrogen storage tank, air separation equipment, a synthetic ammonia tower and an ammonia separation device; The electric energy storage device is used for receiving and storing wind-solar electric energy; the electric hydrolysis device comprises a plurality of electrolytic tanks connected in parallel, receives wind, light and electric energy, performs chemical reaction with water to prepare hydrogen, processes the hydrogen through the purification device, and stores the hydrogen in the hydrogen storage tank; the air separation equipment is used for receiving wind, light and electric energy and separating nitrogen from air; and synthesizing the hydrogen and the nitrogen into ammonia gas by the ammonia synthesizing tower, and sending the ammonia gas into an ammonia separating dev