阅读说明：本技术 一种氢气-电力联产系统与调峰运行方法 (Hydrogen-power cogeneration system and peak shaving operation method ) 是由 高林 洪慧 王朝威 魏延冰 于 2021-09-24 设计创作，主要内容包括：本公开提供了一种氢气-电力联产系统,包括：气化单元(100),用于进行合成气的制备及净化；储气单元(200),用于存储气化单元生产的合成气,并分别向发电单元、制氢单元输送合成气；发电单元(300),其包括燃气轮机(17)和发电机(22),用于使用合成气进行燃气发电；制氢单元(400),用于使用合成气进行脱碳制氢；其中,当电力负荷偏离额定工况时,发电单元(300)利用燃气轮机(17)快速进入调峰运行工况,储气单元(200)即时调整输送给发电单元(300)的合成气的流量,并反向调节制氢单元(400)的制氢产率,以应对电力负荷的变化。本公开还提供了一种氢气-电力联产系统的调峰运行方法。(The present disclosure provides a hydrogen-power cogeneration system, comprising: a gasification unit (100) for the preparation and purification of synthesis gas; the gas storage unit (200) is used for storing the synthesis gas produced by the gasification unit and respectively conveying the synthesis gas to the power generation unit and the hydrogen production unit; a power generation unit (300) including a gas turbine (17) and a generator (22) for gas power generation using the synthesis gas; a hydrogen production unit (400) for performing decarburization hydrogen production using the synthesis gas; when the power load deviates from the rated working condition, the power generation unit (300) rapidly enters the peak-shaving operation working condition by using the gas turbine (17), the gas storage unit (200) immediately adjusts the flow of the synthesis gas transmitted to the power generation unit (300), and reversely adjusts the hydrogen production yield of the hydrogen production unit (400) so as to cope with the change of the power load. The disclosure also provides a peak shaving operation method of the hydrogen-power cogeneration system.)

1. A hydrogen-power cogeneration system, comprising:

a gasification unit (100) for the preparation and purification of synthesis gas;

the gas storage unit (200) is used for storing the synthesis gas produced by the gasification unit and respectively conveying the synthesis gas to the power generation unit and the hydrogen production unit;

a power generation unit (300) comprising a gas turbine (17) and a generator (22) for gas-fired power generation using the syngas;

a hydrogen production unit (400) for performing decarburization hydrogen production using the synthesis gas;

when the power load deviates from the rated working condition, the power generation unit (300) rapidly enters the peak shaving operation working condition by using the gas turbine (17), the gas storage unit (200) instantly adjusts the flow of the synthesis gas transmitted to the power generation unit (300), and reversely adjusts the hydrogen production yield of the hydrogen production unit (400) so as to respond to the change of the power load.

2. Hydrogen-power co-generation system according to claim 1, wherein the gasification unit (100) comprises:

a coal gasification furnace (3) for generating a raw synthesis gas (4) by a gasification reaction using coal (1) and a gasification agent (2);

a waste boiler (5) for cooling the raw synthesis gas (4);

a purification device (6) for removing dust, sulphides and nitrogen oxides from the raw synthesis gas (4).

3. The hydrogen-power cogeneration system of claim 1, wherein the gas storage unit (200) comprises:

a syngas storage tank (8);

and a synthesis gas flow control valve (9) for controlling the synthesis gas flow to the power generation unit (300), and a synthesis gas flow control valve (11) for controlling the synthesis gas flow to the hydrogen production unit (400).

4. Hydrogen-power co-generation system according to claim 2, wherein the hydrogen production unit (400) comprises:

a water gas shift device (13);

CO₂a separation device (14) for separating the separated CO₂(15) After compression and transportation, the hydrogen (16) with high purity is obtained after sealing.

5. Hydrogen-power co-generation system according to claim 4, wherein the power generation unit (300) further comprises:

the waste heat boiler (18) and the steam turbine (20) form a combined cycle power generation system together with the gas turbine (17) and the generator (22); the waste heat boiler (18) is connected with the gas turbine (17).

6. Hydrogen-power co-production system according to claim 5, wherein the waste heat boiler (18) is further adapted to recover sensible heat from the cooling of the raw synthesis gas (4) by the waste heat boiler (5) and to generate recovered steam (23);

the steam turbine (20) is also used for the water gas shift device (13), CO₂The separation device (14) provides the required steam (21).

7. A peak shaving operation method of a hydrogen-power cogeneration system, comprising:

s1, preparing and purifying the synthesis gas through a gasification unit (100);

s2, storing the synthesis gas produced by the gasification unit through a gas storage unit (200), and respectively conveying the synthesis gas to a power generation unit and a hydrogen production unit;

s3, generating power by a power generation unit (300) through gas combustion by using the synthesis gas, wherein the power generation unit (300) comprises a gas turbine (17) and a power generator (22); and decarbonizing the synthesis gas by a hydrogen production unit (400) to produce hydrogen;

when the power load deviates from the rated working condition, the power generation unit (300) rapidly enters the peak shaving operation working condition by using the gas turbine, the gas storage unit (200) instantly adjusts the flow of the synthesis gas transmitted to the power generation unit (300), and reversely adjusts the hydrogen production yield of the hydrogen production unit (400) so as to correspond to the change of the power load.

8. Method of peak shaver operation of a hydrogen-power co-generation system in accordance with claim 7, characterized in that the operation of the gasification unit (100) is kept constant when the power load deviates from the nominal operation.

9. The peak shaver operation method of a hydrogen-power co-generation system as set forth in claim 7, wherein reversely adjusting the hydrogen production yield of the hydrogen production unit (400) comprises:

the gas storage unit (200) reversely adjusts the flow of the synthesis gas delivered to the hydrogen production unit (400), and the gasification unit (100) co-directionally adjusts the yield of the synthesis gas.

10. The peak shaving operation method of a hydrogen-power co-generation system according to claim 7, further comprising:

when the power load is recovered to the rated working condition, the gas storage unit (200) immediately adjusts the flow of the synthesis gas conveyed to the power generation unit (300), and the power generation unit (300) recovers to the rated working condition to operate; and regulating the synthesis gas yield of the gasification unit (100) and the hydrogen production yield of the hydrogen production unit (400) to return the gas storage amount of the gas storage unit (200) to the value of the normal reserve gas amount.

Technical Field

The disclosure relates to the technical field of power and clean fuel production, in particular to a hydrogen-power cogeneration system and a peak shaving operation method.

Background

CO resulting from energy utilization₂The emission accounts for nearly 90% of the total carbon emission in China, and is the main field of emission reduction. The emission reduction technology in the energy field can be divided into the aspects of improving the renewable energy ratio, saving energy, increasing efficiency and CO₂Capture Utilization and Sequestration (CCUS), in which increasing renewable energy ratios to reduce carbon emissions, has become a consensus. However, as the power proportion of renewable energy sources is continuously increased, although the carbon emission intensity is reduced, the safety stability problem of the power system is more prominent: the wind-light-based renewable energy source has the characteristic of discontinuity and instability naturally, and the superposition of the fluctuation of the energy production end and the fluctuation of the user load of the energy consumption end can cause unprecedented challenges to the safe and stable operation of a power grid system, which is also the root cause of the phenomenon of wind and light abandonment. In other words, the goal of achieving both low carbon and safety is a key challenge facing the construction of carbon neutral power systems.

In order to meet the dual challenges of low carbon and safety and improve the consumption capacity of a power grid to renewable energy power, two technical approaches can be mainly adopted, one is energy storage, and the other is reverse peak regulation by utilizing the adjustable and controllable output characteristic of a thermal power plant so as to offset the influence of renewable power fluctuation. It is in this technical background that the peak shaving and variable load operation capabilities of thermal power plants are increasingly gaining importance.

The peak regulation capability of the thermal power plant mainly depends on the dynamic response speed and the variable load depth of the unit. Under the normal condition, the advantages of short starting time, high load-lifting speed, flexible tracking, quick response to load change and the like are achieved, and the peak shaving capacity of the gas turbine unit is far superior to that of a coal-fired unit, so that the gas turbine unit becomes a preferred unit for power grid peak shaving. An Integrated Gasification Combined Cycle (IGCC) is a gas turbine combined cycle power generation technology based on a coal gasification technology, and the IGCC can adopt high-efficiency flexibility by converting coal into gaseous fuelGas turbine, and enabling pollutant and CO conversion in the fuel conversion stage₂The source control of the method is a potential technology for clean and low-carbon utilization of coal. However, the dynamic response characteristics and the variable load capacity of the coal gasification process and the air separation process are far lower than those of the gas turbine cycle, so that the peak regulation capacity of the IGCC power plant is severely limited, and the peak regulation advantage of the gas turbine unit cannot be fully exerted. For example, the load-lifting speed of the Huanentianjin IGCC power plant is only 1-2%/min and is far lower than the load-lifting speed of a gas turbine unit by 5%/min. Furthermore, peak shaving units that operate off of design values are often accompanied by an increase in energy consumption and a decrease in economy. Therefore, it is of great practical significance to explore an energy system capable of realizing high efficiency, low carbon and flexibility at the same time.

Disclosure of Invention

Technical problem to be solved

In view of the above problems, the present disclosure provides a hydrogen-power cogeneration system and a peak shaving operation method, which are used to at least partially solve the technical problems of weak peak shaving capability, high energy consumption, and the like of the conventional hydrogen-power cogeneration system.

(II) technical scheme

One aspect of the present disclosure provides a hydrogen-power cogeneration system, comprising: the gasification unit is used for preparing and purifying the synthesis gas; the gas storage unit is used for storing the synthesis gas produced by the gasification unit and respectively conveying the synthesis gas to the power generation unit and the hydrogen production unit; a power generation unit including a gas turbine and a generator for performing gas power generation using the synthesis gas; a hydrogen production unit for performing decarburization hydrogen production using the synthesis gas; when the power load deviates from the rated working condition, the power generation unit rapidly enters the peak shaving operation working condition by using the gas turbine, the gas storage unit immediately adjusts the flow of the synthesis gas transmitted to the power generation unit, and the hydrogen production yield of the hydrogen production unit is reversely adjusted so as to cope with the change of the power load.

Further, the gasification unit comprises: a coal gasification furnace for generating a raw synthesis gas through a gasification reaction using coal and a gasification agent; a waste boiler for cooling the raw synthesis gas; and the purification device is used for removing dust, sulfide and nitrogen oxide in the crude synthesis gas.

Further, the gas storage unit includes: a syngas storage tank; and a synthesis gas flow control valve for controlling the synthesis gas flow delivered to the power generation unit and a synthesis gas flow control valve for controlling the synthesis gas flow delivered to the hydrogen production unit.

Further, the hydrogen production unit includes: a water gas shift device; CO 2₂A separation device for separating the separated CO₂And after compression and transportation, sealing and storing, the high-purity hydrogen is obtained.

Further, the power generation unit further includes: the waste heat boiler, the steam turbine, the gas turbine and the generator form a combined cycle power generation system; the waste heat boiler is connected with the gas turbine.

Furthermore, the waste heat boiler is also used for recovering sensible heat in the process of cooling the crude synthesis gas by the waste boiler and generating steam; steam turbines, also for water gas shift devices, CO₂The separation device provides the required steam.

In yet another aspect, the present disclosure provides a peak shaving operation method of a hydrogen-power cogeneration system, including: s1, preparing and purifying the synthesis gas through a gasification unit; s2, storing the synthesis gas produced by the gasification unit through a gas storage unit, and respectively conveying the synthesis gas to a power generation unit and a hydrogen production unit; s3, generating power by using the synthesis gas through a power generation unit, wherein the power generation unit comprises a gas turbine and a generator; and decarbonizing and producing hydrogen by using the synthesis gas through a hydrogen production unit; when the power load deviates from the rated working condition, the power generation unit rapidly enters the peak shaving operation working condition by using the gas turbine, the gas storage unit immediately adjusts the flow of the synthesis gas transmitted to the power generation unit, and the hydrogen production yield of the hydrogen production unit is reversely adjusted so as to cope with the change of the power load.

Further, when the electric load deviates from the rated working condition, the working condition of the gasification unit is kept unchanged.

Further, reverse tuning the hydrogen production yield of the hydrogen production unit comprises: the gas storage unit reversely adjusts the flow of the synthesis gas conveyed to the hydrogen production unit, and the gasification unit synchronously adjusts the yield of the synthesis gas.

Further, still include: when the power load is recovered to the rated working condition, the gas storage unit immediately adjusts the flow of the synthesis gas transmitted to the power generation unit, and the power generation unit recovers to operate under the rated working condition; and regulating the synthesis gas yield of the gasification unit and the hydrogen production yield of the hydrogen production unit to return the gas storage amount of the gas storage unit to the normal gas reserve value.

(III) advantageous effects

According to the hydrogen-power cogeneration system and the peak shaving operation method, the dynamic characteristic decoupling of the power generation unit and the hydrogen production unit is realized by using the gas storage unit, and the quick response characteristic of the gas turbine unit is fully utilized; when the power load is recovered to the rated working condition, the gasification unit maintains the running of the rated working condition, and the overall peak regulation performance of the system is prevented from being affected by the air separation and gasification equipment with the worst dynamic characteristics; the hydrogen production unit removes CO while producing hydrogen₂The high-carbon carbide fuel is compressed and sealed, so that low-carbon utilization of the high-carbon carbide fuel is realized; under the variable load working condition, only part of equipment is in variable load operation, and performance loss caused by variable load of the whole system is avoided.

Drawings

Fig. 1 schematically illustrates a schematic structural view of a hydrogen-power cogeneration system in accordance with an embodiment of the present disclosure;

FIG. 2 schematically illustrates a flow chart of a method of peak shaving operation of a hydrogen-power co-generation system in accordance with an embodiment of the disclosure;

FIG. 3 schematically illustrates a dynamic response process of various process flows in a hydrogen-power cogeneration system in accordance with an embodiment of the disclosure;

the reference numbers illustrate:

100: a gasification unit; 200: a gas storage unit; 300: a power generation unit; 400: a hydrogen production unit; 1: coal; 2: a gasifying agent; 3: a coal gasifier; 4: crude synthesis gas; 5: a waste pot; 6: a purification device; 7: synthesis gas; 8: a syngas storage tank; 9: a synthetic gas flow control valve of the power generation unit; 10: generating electricity and synthesizing gas; 11: a synthesis gas flow control valve of the hydrogen production unit; 12: hydrogen production of synthesis gas; 13: a water gas shift device; 14: CO 2₂A separation device; 15: CO 2₂(ii) a 16: high purity hydrogen; 17: a gas turbine; 18: a waste heat boiler; 19: smoke discharge of the waste heat boiler; 20: a steam turbine; 21: steam generating device(ii) a 22: a generator; 23: and recovering the steam.

Detailed Description

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

Aiming at the problems that the utilization of fossil energy presents high carbon emission and renewable energy harms the safe operation of a power grid and the like in the current carbon and under the background, the hydrogen-power cogeneration system and the peak shaving operation method based on coal gasification are provided in the disclosure, so that the low-carbon, flexible and efficient utilization of fossil fuel is realized.

An embodiment of the present disclosure provides a hydrogen-power cogeneration system, please refer to fig. 1, including: a gasification unit 100 for preparation and purification of synthesis gas; the gas storage unit 200 is used for storing the synthesis gas produced by the gasification unit and respectively conveying the synthesis gas to the power generation unit and the hydrogen production unit; a power generation unit 300 including a gas turbine 17 and a generator 22 for gas-fired power generation using the synthesis gas; a hydrogen production unit 400 for performing decarburization hydrogen production using the synthesis gas; when the power load deviates from the rated working condition, the power generation unit 300 rapidly enters the peak shaving operation working condition by using the gas turbine 17, the gas storage unit 200 immediately adjusts the flow rate of the synthesis gas delivered to the power generation unit 300, and reversely adjusts the hydrogen production yield of the hydrogen production unit 400 to cope with the change of the power load.

The cooled and purified synthesis gas produced by the gasification unit 100 is stored in the gas storage unit 200, and the design capacity of the gas storage unit 200 depends on the dynamic characteristics (peak shaving depth and peak shaving speed) of the power generation unit 300 and the adjustable yield characteristics (adjustable amplitude and adjustable speed) of the gasification unit 100 and the hydrogen production unit 400. The synthesis gas leaving the gas storage unit 200 is divided into two streams, one stream is sent to the hydrogen production unit 400 as feed gas, and hydrogen is produced after water gas shift and decarburization; the other is sent to the power generation unit 300 as fuel to generate power. When the power load deviates from the rated working condition; the gas storage unit 200 adjusts the flow of the fuel gas sent to the power generation unit 300 in real time, and the power generation unit 300 can quickly enter a peak shaving operation condition by utilizing the good dynamic response characteristic of the gas turbine 17 so as to meet the variable load requirement; meanwhile, the gasification unit 100 can adjust the yield of the synthesis gas in the same direction (relative to the load adjustment direction of the power generation unit) or keep the working condition unchanged, the gas storage unit 200 adjusts the flow rate of the raw material gas of the hydrogen production unit in the opposite direction (relative to the load adjustment direction of the power generation unit), and the gasification unit 100 and the hydrogen production unit 400 run under the variable load working condition. The dynamic characteristic decoupling of the power generation unit 300 and the hydrogen production unit 400 is realized through the gas storage unit, and the quick response characteristic of the gas turbine 17 unit is fully realized.

The system mainly comprises processes of coal gasification gas production (gasification unit 100), synthesis gas storage (gas storage unit 200), decarburization hydrogen production (hydrogen production unit 400) and gas-steam combined cycle power generation (power generation unit 300). Through the design of integration and operation strategies among gas production, gas storage, hydrogen production and power generation units, the system can reduce the carbon emission of a coal-based energy system, realize quick response to the load change of a power grid, and simultaneously keep higher energy utilization efficiency and good economy, namely realize three goals of low carbon, flexibility and high efficiency.

On the basis of the above embodiment, the gasification unit 100 includes: a coal gasifier 3 for generating a raw synthesis gas 4 by a gasification reaction using coal 1 and a gasifying agent 2; a waste boiler 5 for cooling the raw synthesis gas 4; and the purification device 6 is used for removing dust, sulfide and nitrogen oxide in the raw synthesis gas 4.

The gasification unit 100 comprises a process for preparing and purifying synthesis gas such as an air separation and coal gasification furnace, a waste boiler 5, a purification device 6 and the like, takes coal 1 or other solid fuels as raw materials, and firstly reacts with a gasification agent 2 such as oxygen, water vapor and the like to generate crude synthesis gas 4; cooling and dedusting the high-temperature crude synthesis gas 4 by the waste boiler 5, then feeding the cooled and dedusted high-temperature crude synthesis gas into the purification device 6 for desulfurization and denitration, wherein the treated synthesis gas 7 mainly contains CO and H₂、CO₂And sent to the gas storage unit 200.

The design capacity of the gasification unit 100 should be able to meet both the power rating of the power generation unit 300 and the design yield of the hydrogen generation unit 400.

On the basis of the above embodiment, the gas storage unit 200 includes: a synthesis gas storage tank 8; and a synthesis gas flow control valve 9 for controlling the supply to the power generation unit 300, and a synthesis gas flow control valve 11 for controlling the supply to the hydrogen production unit 400.

The gas storage unit 200 includes a synthesis gas storage tank 8, the synthesis gas in the synthesis gas storage tank 8 is divided into two streams, one stream is used as a feed gas and sent to the hydrogen production unit 400 through a synthesis gas flow control valve 11, and hydrogen is produced after water gas shift and decarburization; the other stream is sent as fuel to the power generation unit 300 through the synthesis gas flow control valve 9.

The reserve gas should be stored in the gas storage unit 200 at a value depending on the difference between the variable load demand of the power generation unit 300 and the adjustable magnitude of the yields and the dynamic response speed of the gasification unit 100 and the hydrogen generation unit 400.

On the basis of the above embodiment, hydrogen production unit 400 includes: a water gas shift device 13; CO 2₂A separation device 14 for separating the separated CO₂15, the hydrogen gas is compressed, transported and sealed to obtain the high-purity hydrogen gas 16.

The hydrogen production unit comprises water gas shift, CO₂A separation process; production of hydrogen by water gas shift and decarbonation, decarbonation of the resulting CO₂Compressing and sealing to realize carbon emission reduction.

On the basis of the above embodiment, the power generation unit 300 further includes: the waste heat boiler 18, the steam turbine 20, the gas turbine 17 and the generator 22 form a combined cycle power generation system; the waste heat boiler 18 is connected to the gas turbine 17.

The power generation unit 300 includes a gas turbine 17, a waste heat boiler 18, a steam turbine 20, and a generator 22, which constitute a gas/steam combined cycle power generation unit.

On the basis of the above embodiment, the exhaust-heat boiler 18 is further configured to recover sensible heat generated during the process of cooling the raw synthesis gas 4 by the waste boiler 5 and generate recovered steam 23; steam turbine 20, also for water gas shift device 13, CO₂The separation device 14 provides the required steam 21.

The fuel of the gas turbine 17 in the power generation unit 300 is derived from the gas storage unit 200, and the steam 21 is circulated to provide steam for the hydrogen production unit 400, so that the water gas shift and CO conversion are satisfied₂Steam requirements of the separation process.

To sum up, the coal 1 in the hydrogen-power co-production system firstly passes through the coal gasifier 3 to generate the crude synthesis gas 4, and the crude synthesis gas 4 is sent into the gas storage unit 200 after being cooled by the waste boiler 5 and purified by the purification device 6. A strand of synthesis gas 12 from the gas storage unit 200 enters a hydrogen production unit and undergoes water gas shift and CO conversion₂Obtaining high purity hydrogen 16 after separation; the other stream of syngas 10 enters a gas-steam combined cycle power generation unit (comprising a gas turbine 17, a waste heat boiler 18, a steam turbine 20, and a generator 22) to be used as fuel for power generation.

The design capacity of the gasification unit 100 in this disclosure should be able to meet both the power rating of the power generation unit 300 and the design yield of the hydrogen generation unit 400. The cooled and purified synthesis gas enters a synthesis gas storage tank 8, and under the condition that the system operates stably, part of the synthesis gas enters a hydrogen production unit 400 to produce pure hydrogen; a part of the synthesis gas enters a power generation unit 300 for power generation; in addition, a portion of the synthesis gas is always available in the synthesis gas tank 8 to cope with the rapidly changing synthesis gas demand of the power unit during peak shaving. The synthetic gas storage tank 8 is equivalent to a chemical energy storage unit, and the power output load range of the whole system in the peak shaving process is increased so as to meet the load change requirement of a power grid and realize the decoupling of dynamic characteristics among different units. The hydrogen production unit 400 produces hydrogen through water gas shift and decarburization processes, and removes CO while producing hydrogen₂And the high-carbon carbide fuel is compressed and sealed, so that the low-carbon utilization of the high-carbon carbide fuel is realized.

The present disclosure also provides a peak shaving operation method of a hydrogen-power cogeneration system, please refer to fig. 2, which includes: s1, preparation and purification of syngas by gasification unit 100; s2, storing the synthesis gas produced by the gasification unit through the gas storage unit 200, and respectively conveying the synthesis gas to the power generation unit and the hydrogen production unit; s3, generating power by gas combustion using the synthesis gas through the power generation unit 300, the power generation unit 300 including the gas turbine 17 and the generator 22; and decarbonizing by using the synthesis gas through the hydrogen production unit 400 to produce hydrogen; when the power load deviates from the rated working condition, the power generation unit 300 rapidly enters the peak shaving operation working condition by using the gas turbine, the gas storage unit 200 immediately adjusts the flow rate of the synthesis gas delivered to the power generation unit 300, and reversely adjusts the hydrogen production yield of the hydrogen production unit 400 to cope with the change of the power load.

According to the hydrogen-electricity cogeneration system and the peak regulation operation method based on the coal gasification and gas turbine combined cycle, through the arrangement of the gas storage unit and the system integration design, the system can realize the functions of high-efficiency power generation, low-carbon hydrogen production and flexible deep peak regulation. Specifically, the hydrogen-electricity cogeneration system uses coal as a raw material, the coal 1 and a gasifying agent 2 are firstly subjected to gasification reaction to generate a crude synthesis gas 4, the crude synthesis gas is cooled by a waste boiler 5 (sensible heat recovery generates recovered steam 23), and then the crude synthesis gas is sent to a gas storage unit 200 after dust, sulfide and nitrogen oxide are removed by a purification device 6, namely step S1. One strand of the synthesis gas 12 of the gas storage unit 200 is sent to the hydrogen production unit 400 and undergoes water gas shift and CO conversion₂Preparing hydrogen after separation, separating obtained CO₂15, sealing and storing after compression and transportation; the other synthetic gas 10 enters a power generation unit to drive a combined cycle power generation system consisting of a gas turbine 17, a waste heat boiler 18, a steam turbine 20 and a power generator 22; steam turbines for water gas shift and CO₂The separation process provides the required steam 21, i.e. steps S2, S3.

When the power load deviates from the rated working condition, the gas storage unit 200 adjusts the flow of the fuel gas sent to the power generation unit 300 in time, and the power generation unit 300 can quickly enter the peak shaving operation working condition by utilizing the good dynamic response characteristic of the gas turbine 17 so as to meet the load change requirement; meanwhile, the hydrogen production yield of the hydrogen production unit 400 is reversely adjusted, and the hydrogen production unit enters the variable-load working condition to operate.

On the basis of the above embodiment, when the power load deviates from the rated operating condition, the operating condition of the gasification unit 100 is kept unchanged.

The working condition of the gasification unit 100 is kept unchanged, the gasification unit 100 always keeps running under the rated working condition, and the overall peak regulation performance of the system is prevented from being affected by the worst air separation and gasification equipment in dynamic characteristics; under the variable load working condition, only part of equipment is in variable load operation, and performance loss caused by variable load of the whole system is avoided.

On the basis of the above embodiment, the reverse-regulating the hydrogen production yield of the hydrogen production unit 400 includes: the gas storage unit 200 reversely adjusts the flow rate of the synthesis gas delivered to the hydrogen production unit 400, and the gasification unit 100 co-directionally adjusts the yield of the synthesis gas.

The hydrogen production yield of the reverse regulation hydrogen production unit 400 may specifically be that the gas storage unit 200 adjusts the raw material gas flow rate of the hydrogen production unit in a reverse direction (direction adjusted relative to the load of the power generation unit), and meanwhile, the gasification unit 100 may also adjust the yield of the synthesis gas in the same direction at the same time.

On the basis of the above embodiment, the method further includes: when the power load is recovered to the rated working condition, the gas storage unit 200 immediately adjusts the flow of the synthesis gas transmitted to the power generation unit 300, and the power generation unit 300 recovers to the rated working condition to operate; and adjusts the syngas yield of the gasification unit 100 and the hydrogen production yield of the hydrogen production unit 400 such that the gas storage amount of the gas storage unit 200 returns to the normal gas value.

When the power load recovers from the variable working condition to the rated working condition, firstly, the power generation unit 300 recovers the rated working condition to operate by adjusting the flow of the fuel gas sent to the power generation unit 300 by the gas storage unit 200; and meanwhile, the yield of the gasification unit 100 and the hydrogen production unit 400 is adjusted, so that the gas amount of the gas storage unit 200 returns to the value of the normal gas amount, and then the rated yield of the gasification unit 100 and the hydrogen production unit 400 is recovered. Through the organic integration of the gas storage unit, the power generation unit and the hydrogen production unit, the reverse variable load of the power generation unit and the hydrogen production unit operates in a coordinated manner, the overall peak regulation capacity of the hydrogen-electricity cogeneration system is improved, and the effects of low-carbon utilization of fossil energy and efficient and flexible peak regulation of a power grid are realized.

The present disclosure is further illustrated by the following detailed description.

Fig. 1 is a schematic diagram of the low-carbon flexible peak shaving system. The system mainly comprises a gasification unit 100, a gas storage unit 200, a power generation unit 300 and a hydrogen production unit 400.

(1) Gasification unit, power generation unit, and method for selecting capacity of hydrogen production unit

The variable load demand of the system is mainly caused by the fluctuation of the power load, and the capacities of the gasification unit, the power generation unit and the hydrogen production unit are selected according to the following basic principle: under the premise of considering the market demand of hydrogen/electricity products, the capacity ratio of the hydrogen production unit and the power generation unit is not suitable to be too small or too large. The larger the capacity of the hydrogen production unit is, the stronger the stabilizing capability of the load fluctuation of the power generation unit through reverse peak regulation operation is; conversely, the smaller the power generation unit capacity, the weaker its peaking effect. When the same fuel quantity is consumed, the yield of the hydrogen production unit is about 3-4 kilo square/h corresponding to the generating power of 100 MW. If the power generation capacity is 1, it is recommended that the hydrogen/capacity ratio is selected to be 0.8 to 2.5. Secondly, the rated yield of the gasification unit simultaneously meets the gas consumption under the rated load of the power generation unit and the hydrogen production unit, and a 110% capacity coefficient can be selected in consideration of the peak regulation requirement.

(2) Syngas storage tank capacity selection

In the peak shaving process, the variation of the synthetic gas of the storage tank should satisfy:

wherein S_DIs the reserve gas storage capacity (or called rated load gas storage capacity) of the storage tank, S_maxIs the maximum gas storage capacity, Δ L, of the storage tank_P＝L_P(t)-L_P(t₀)，ΔL_C＝L_C(t)-L_C(t₀)，ΔL_G＝L_G(t)-L_G(t₀) The syngas variation functions for the power generation unit, the hydrogen production unit, and the gasification unit, respectively. The peak shaving process starts from the unit which firstly enters the load response to the unit which finally finishes the load response, namely the process that each unit of the system is adjusted from the current load to the target load. t is t₀As peak shaving start time, t_fIs the peak shaver end time.

The reserve gas volume and the storage tank volume meet the following conditions:

andthe maximum variation of the synthesis gas in the storage tank during the process of load up-regulation (reduction of the gas amount in the storage tank) or load down-regulation (increase of the gas amount in the storage tank) of the power generation unit respectively depends on the peak regulation time and the load variation functions of the gasification unit, the power generation unit and the hydrogen production unit.

(3) Control strategy for fast peak regulation and variable load operation method

Based on the dynamic response characteristics of the gasification unit, the gas storage unit, the hydrogen production unit and the power generation unit, aiming at different peak regulation requirements, the control strategy of rapid peak regulation is as follows:

firstly, judging a peak shaving scheme based on the peak shaving requirement. When the peaking scheme is selected, formula (1) can be rewritten into the form of formula (4):

and when the hydrogen production unit or the gasification unit is required to be subjected to load change in the peak shaving process, respectively taking 1 for i and j, or taking 0 for i and j. For example, for a given S_maxAnd S_DWhen is coming into contact withWhen the formula (4) can be met, only the storage tank is needed to be used as an auxiliary peak regulation, and the method is only suitable for the process with smaller peak regulation depth; when in useCannot satisfy the formula (4), butIf the peak regulation can be satisfied, selecting a gas storage unit and a hydrogen production unit to participate in peak regulation (i is 1); when only haveWhen the formula (4) can be satisfied, the gas storage tank, the hydrogen production unit and the gasification unit all participate in peak shaving (i is 1 and j is 1), and the scheme is suitable for the process of deep peak shaving, but the reduction of the system performance is obvious.

After the peak regulation scheme is determined, the peak regulation steps are as follows: the gas storage unit acts first to adjust the flow rate of the synthesized gas of the power generation unit; reversely adjusting the yield of the hydrogen production unit; regulating the yield of the gasification unit in the same direction; and fifthly, each unit reaches the target load and stably operates.

The application scenario of the invention will be described below from a specific case.

The assumptions for this case are as follows: the capacity of the power generation unit is 300MW, the variable load range is 30% -110%, the load of the power generation unit is reduced from 100% to 30%, the long-lasting variable load time is 10 hours, and the dynamic response rate is 5%/min; the capacity of the hydrogen production unit is 10 ten thousand square/h, the variable load range is 70-120%, and the dynamic response rate is 1%/min; the variable load range of the gasification unit is 70-120%, and the dynamic response rate is 0.5%/min. Other assumptions are shown in table 1, assuming that the efficiency of each cell does not change with changes in load.

Table 1 case hypothesis conditions

Cold gas efficiency	80％
		Energy conversion efficiency of power generation unit	60％
Energy conversion efficiency of hydrogen production unit	60％
		Heat value of coal	29270kJ/kg
Heat value of synthesis gas	10636kJ/kg
		Heating value of hydrogen	142351kJ/kg
25bar, 20 ℃ synthesis gas volume	0.0457m3/kg

The method of calculating the required tank capacity is as follows:

it is known that WhereinAndthe mass flow rates (kg/min) of the synthesis gas of the gasification unit, the hydrogen production unit and the power generation unit are respectively.

Therefore, the flow rates of the synthesis gas at 30%/100%/110% load of the power generation unit can be calculated as: 846/2820/3102kg/min, maximum syngas Change Rate 141.12kg/min²。

The flow rates of the synthesis gas at 70%/100%/120% load of the hydrogen production units are 2322.6/3318/3981.6kg/min respectively, and the maximum synthesis gas change rate is 33.12kg/min²。

The syngas flow rates at 70%/100%/120% load of the gasification units were 4296.6/6138/7365.6kg/min, respectively, with a maximum syngas variation rate of 30.69kg/min²。

It is assumed that each unit in the peaking process is operating at the maximum load change rate. The power generation unit load is reduced from 100% to 30% load, the flow rate is reduced by 1974kg/min, the hydrogen generation unit load is increased from 100% to 120%, and the flow rate can only be increased by 663.6kg/min, so that the flow rate of the gasification unit must be reduced by 1310.4kg/min to ensure that the syngas storage capacity in the storage tank does not increase. From this, the amount of the synthesis gas flow and the amount of the storage in the storage tank can be calculated for each unit, as shown in fig. 3. The power generation unit is first lowered to a target load state, then the hydrogen production unit and the gasification unit are carried out, and the synthesis gas in the storage tank is increased by 20818kg at most. Therefore, to cope with the peak shaver under this condition, the tank must have 952m at the initial moment of the peak shaver process³Space (storage conditions for synthesis gas 25bar, 20 ℃). Similarly, the storage capacity of the storage tank under the rated working condition can be calculated according to the peak load regulation process of the power generation unit (the load of the power generation unit is increased from 100% to 110%), and is 919kg (42 m)³). Thus, a total storage tank volume of at least 994m at 20 ℃ under storage conditions of 25bar is required³Wherein the constant gas storage is at least 42m³。

From the above examples, it can be seen that the storage tank design is primarily dependent on the variable load characteristics of the power generation unit and the hydrogen generation unit, including the variable load depth and rate. The existence of the synthetic gas storage tank increases the load change range and the change rate of the power generation unit, realizes deep peak regulation, reduces the influence of the load change of the power generation unit on the gasification unit and the hydrogen production unit, and realizes the decoupling of the dynamic characteristics of different units.

The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.