阅读说明：本技术 一种提高热电机组灵活性的热电氢多联产系统 (Thermoelectric hydrogen poly-generation system for improving flexibility of thermoelectric unit ) 是由 杜威 张营 王志强 李铁军 杨海生 于 2019-09-05 设计创作，主要内容包括：本发明涉及一种提高热电机组灵活性的热电氢多联产系统,其包括相互连接的电解水制氢子系统、汽轮发电机子系统以及抽汽供热子系统。本发明适用于热电联产机组乃至纯凝机组,能够在投资较少、安全性有保障、运行调整方便快捷、调峰范围大、对机组运行热经济性影响小的前提下,显著提高其灵活性。本发明将电解水制氢技术、蒸汽轮机技术和抽汽供热技术有机结合,提高机组灵活性的同时兼顾了热经济性。(The invention relates to a heat, power and hydrogen poly-generation system for improving the flexibility of a thermoelectric unit, which comprises a water electrolysis hydrogen production subsystem, a steam turbine generator subsystem and a steam extraction heat supply subsystem which are connected with each other. The invention is suitable for cogeneration units and even straight condensing units, and can obviously improve the flexibility on the premise of less investment, safety guarantee, convenient and quick operation adjustment, large peak regulation range and small influence on the operation heat economy of the units. The invention organically combines the water electrolysis hydrogen production technology, the steam turbine technology and the steam extraction heat supply technology, improves the flexibility of the unit and simultaneously considers the heat economy.)

1. A heat, power and hydrogen poly-generation system for improving the flexibility of a thermoelectric unit is characterized by comprising a water electrolysis hydrogen production subsystem, a steam turbine generator subsystem and a steam extraction heat supply subsystem which are mutually connected.

2. The heat and power hydrogen poly-generation system for improving the flexibility of the thermoelectric generating set is characterized in that the water electrolysis hydrogen production subsystem comprises an electrolytic bath (9), a separation scrubber (12), an alkali liquor cooler (14), an alkali liquor circulating pump (8), a filter (13), a hydrogen storage tank (15), an AC/DC converter (7), a raw water tank (10) and a water replenishing pump (11);

the AC/DC converter (7) is connected into an electrolytic tank (9), and the outlet of the electrolytic tank (9) is connected with the inlet of a separation scrubber (12); the raw material water tank (10) is connected with the separation washer (12) through a water replenishing pump (11); the liquid outlet of the separation scrubber (12) is connected with a filter (13), and the gas outlet of the separation scrubber (12) is connected with a hydrogen storage tank (15); the filter (13) is communicated with the inlet of the electrolytic cell (9) through an alkali liquor cooler (14) and an alkali liquor circulating pump (8).

3. The heat and power hydrogen poly-generation system for improving the flexibility of the thermoelectric generating set is characterized in that the steam turbine generator subsystem comprises a steam turbine (1), a generator (2), a transformer bank (3), a condenser (4), a steam extraction heat recovery system (6) and a condensate pump (5);

the steam turbine (1) drives the generator (2), and the generator (2) supplies power to an external power grid and the AC/DC converter (7) through the transformer bank (3); and the exhaust steam generated by the steam turbine (1) is condensed by the condenser (4) and then is sent to the steam extraction heat returning system (6) by the condensate pump (5).

4. The cogeneration system of claim 3, wherein said extraction and supply subsystem comprises a heating regulating valve (18), a heating network heater (17) and a drain pump (16);

the heat supply extraction steam outlet of the steam turbine (1) is connected with the steam side inlet of the heat supply network heater (17) through a heat supply adjusting valve (18), and the steam side outlet of the heat supply network heater (17) is connected with the extraction steam heat recovery system (6) through a drainage pump (16).

5. The heat and power hydrogen poly-generation system for improving the flexibility of the thermoelectric generating set is characterized in that the condensed water pump (5) sends condensed water into the steam extraction heat recovery system (6) to be heated and then sends the heated condensed water to the boiler to generate main steam, and the main steam drives the steam turbine (1) to operate.

6. The system for increasing the flexibility of a thermoelectric power unit as claimed in claim 5, wherein the raw water tank (10) and the condensate pump (5) are respectively connected with a chemical water production system of a power plant.

7. The poly-generation system of heat and power with increased flexibility of thermoelectric power unit as claimed in claim 6, wherein the electrolytic cell (9) is filled with an aqueous solution of potassium hydroxide or sodium hydroxide with a concentration of 20 ~ 30% by mass.

8. The system for combined heat and power generation with increased flexibility of a thermoelectric power plant according to claim 7, characterized in that the operating temperature of the electrolysis cell (9) is 80-85 ℃.

9. The system for increasing the flexibility of the thermoelectric generating set of claim 8, wherein the inlet and outlet of the water side of the heating network heater (17) are respectively connected with the cold and hot water pipelines of the circulating water of the heating network.

10. The cogeneration system of claim 9, wherein said heat network heater (17) is a shell and tube heat exchanger.

Technical Field

The invention relates to a heat and power hydrogen poly-generation system for improving the flexibility of a thermoelectric unit.

Background

With the enhancement of environmental awareness of people, the usage amount of hydrogen is increasing day by day because the heat value of the combusted hydrogen is very high and the environment is not polluted. For the production of hydrogen, the water electrolysis hydrogen production technology is one of the widely applied and mature methods at present. The hydrogen production process using water as raw material is the reverse process of hydrogen and oxygen combustion to generate water, so that water can be decomposed into hydrogen and oxygen by providing a certain amount of energy. The efficiency of hydrogen produced by the decomposition of water by the supply of electrical energy is typically 75% to 85%. The process is simple, pollution is avoided, and the application of the process is limited to a certain extent because the power consumption is large. At present, the water electrolysis process and equipment are continuously improved, but the energy consumption for hydrogen production by water electrolysis is still high.

The method for improving the flexibility of the thermoelectric unit mainly comprises the heat supply by using an electric boiler, the heat storage technology by using various heat storage tanks, the steam flow reconstruction technology represented by zero output of a low-pressure cylinder, various low-load stable combustion technologies and the like. The above techniques all have certain drawbacks.

The electric boiler technology directly uses electricity to supply heat to the outside, the loss of energy quality is large, and the comprehensive utilization efficiency of energy is relatively low. The heat storage tank has large investment and only supplements the insufficient heat supply capacity of the unit caused by the reduction of the power generation load. The low-pressure cylinder zero-output technology has certain dangers, such as blade ultra-temperature and water erosion. In addition, the technology mainly focuses on meeting the peak regulation requirement of a power grid on a unit, and has little negative influence on how to improve the peak regulation on the operation heat economy.

The prior art for improving the flexibility of the unit mainly has the following problems:

(1) the existing method for improving the flexibility of the thermoelectric unit has the defects of insufficient safety, for example, the low-pressure cylinder zero-output technology has the risks of blade overtemperature, water erosion and the like.

(2) The existing method for improving the flexibility of the thermoelectric power unit has poor heat economy, for example, the electric boiler technology is used for directly converting high-quality electric energy into low-quality heat energy, which is not economical in thermodynamic sense.

(3) The operation adjustment rapidity of the conventional method for improving the flexibility of the thermoelectric unit is still to be improved. It is desirable to try to make the response of the electrical and thermal loads of the unit to the scheduling requirements faster.

(4) The peak shaving range of the conventional method for improving the flexibility of the thermoelectric unit is relatively limited. Because the heat and the electricity of the traditional unit are in a strong coupling relation, the heat and the electricity are restricted with each other, the adjustment of the heat and the electricity can be greatly limited, and the operation flexibility is very low. The existing various thermoelectric decoupling technologies and low-load combustion stabilizing technologies can only relieve the contradiction to a certain extent.

Disclosure of Invention

In view of the above problems, the present invention provides a poly-generation system of hydrogen and heat for improving the flexibility of a cogeneration unit, which is suitable for cogeneration units and even straight condensing units, and can significantly improve the flexibility of the cogeneration unit on the premise of less investment, guaranteed safety, convenient and rapid operation adjustment, large peak regulation range, and small influence on the thermal economy of unit operation. The system organically combines the water electrolysis hydrogen production technology, the steam turbine technology and the steam extraction heat supply technology, improves the flexibility of the unit and simultaneously considers the heat economy.

The invention adopts the following technical scheme:

a heat, power and hydrogen poly-generation system for improving the flexibility of a thermoelectric unit comprises a water electrolysis hydrogen production subsystem, a steam turbine generator subsystem and a steam extraction heat supply subsystem which are connected with each other.

The water electrolysis hydrogen production subsystem comprises an electrolytic bath, a separation washer, an alkali liquor cooler, an alkali liquor circulating pump, a filter, a hydrogen storage tank, an AC/DC converter, a raw material water tank and a water replenishing pump.

Wherein the AC/DC converter is connected into an electrolytic bath, and the outlet of the electrolytic bath is connected with the inlet of the separation scrubber; the raw material water tank is connected with the separation washer through a water replenishing pump; the liquid outlet of the separation scrubber is connected with the filter, and the gas outlet of the separation scrubber is connected with the hydrogen storage tank; the filter is communicated with the inlet of the electrolytic cell through the alkali liquor cooler and the alkali liquor circulating pump.

The steam turbine generator subsystem comprises a steam turbine, a generator, a transformer bank, a condenser, a steam extraction heat recovery system and a condensate pump.

The steam turbine drives a generator, and the generator supplies power to an external power grid and the AC/DC converter through a transformer bank; and after being condensed by a condenser, the exhaust steam (low-pressure steam) generated by the steam turbine is sent to a steam extraction heat recovery system by a condensate pump.

The steam extraction and heat supply subsystem comprises a heat supply adjusting valve, a heat supply network heater and a drainage pump.

And a heat supply steam extraction outlet of the steam turbine is connected with a steam side inlet of the heat supply network heater through a heat supply regulating valve, and a steam side outlet of the heat supply network heater is connected with a steam extraction heat regeneration system through a drain pump.

The condensed water is sent into the steam extraction heat recovery system by the condensed water pump to be heated and then is sent to the boiler to generate main steam, and the main steam drives the steam turbine to operate.

Wherein, raw materials water tank and condensate pump are indirect power plant's chemistry water production system respectively.

Wherein the electrolytic bath is filled with 20-30% by mass of an aqueous solution of potassium hydroxide or sodium hydroxide.

Wherein the working temperature of the electrolytic cell is 80-85 ℃.

And the water side inlet and outlet of the heat supply network heater are respectively connected with a cold and hot water pipeline of heat supply network circulating water.

Wherein, the heat supply network heater is a shell-and-tube heat exchanger.

The invention has the beneficial effects that: the method has the advantages of less investment, good economy, guaranteed safety, convenient and quick operation adjustment and large peak regulation range.

(1) Less investment

Compared with the hydrogen production method by fossil and chemical raw materials represented by a water gas method, a natural gas method and a petroleum cracking method, the hydrogen production method by water electrolysis has the advantages of simple process flow, easily obtained raw materials, continuous emergence of new low-cost catalysts, and more efficient electro/photoelectrocatalysis water cracking oxygen evolution reaction, thereby improving the hydrogen preparation efficiency and further reducing the hydrogen production cost.

(2) Good thermal economy

According to the hydrogen-heat poly-generation system, when the surplus power of the system is generated due to power grid peak regulation and heat supply network adjustment, the surplus power can be electrolyzed to prepare hydrogen, so that the high-quality high-price secondary energy is obtained, and the steam turbine can also operate in a high-load and high-heat-efficiency state for a long time. When the peak regulation of the power grid and the adjustment of the heat supply network cause that the system has no surplus power, the production of hydrogen can be reduced or suspended, and the hydrogen can be continuously produced by purchasing power from the power grid as appropriate.

(3) Convenient and fast operation and adjustment

The water electrolysis hydrogen production system can rapidly adjust the load to adapt to the changes of a steam turbine power generation system and a steam extraction heat supply system. In addition, no strong coupling relation exists between hydrogen production, power generation and heat supply, so that the self operation strategy can be flexibly determined according to the current conditions of an external power grid and a heat supply network, and the flexibility of the whole system is improved.

(4) Large peak regulation range

Compared with other methods for enhancing flexibility, the method can enable the thermoelectric unit to obtain a larger peak regulation range. By referring to historical data and supply and demand forecast of a power grid and a heat supply network and reasonably designing the capacity of the water electrolysis hydrogen production system, surplus power of the unit can be fully absorbed in the valley of the power grid.

(5) Good in safety

The technology for producing hydrogen by electrolyzing water has been developed for hundreds of years, and as a rather mature technology, a perfect safety design standard system and safety management specifications have been formed in the aspects of system safety, electrical safety, equipment safety and the like. In the actual industrial production process, the safety and the reliability of the water electrolysis hydrogen production technology are verified.

In conclusion, the invention effectively overcomes the defects of the prior method and has obvious progress in investment amount, thermal economy, safety, operation adjustment convenience and peak regulation range.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

FIG. 2 is a schematic diagram of a water electrolysis hydrogen production subsystem.

FIG. 3 is a schematic diagram of a turbonator subsystem.

FIG. 4 is a schematic diagram of an extraction heating subsystem.

Wherein, 1 steam turbine, 2 generators, 3 transformer banks, 15 hydrogen storage tanks, 7 AC/DC converter, 9 electrolysis trough, 14 alkali liquor cooler, 13 filters, 12 separation scrubber, 8 alkali liquor circulating pump, 11 water replenishing pump, 10 raw material water tank, 4 condenser, 5 condensate pump, 16 drain pump, 17 heat network heater, 6 steam extraction heat recovery system, 18 heat supply regulating valve.

Detailed Description

The present invention will be described in detail with reference to the following examples and drawings. The scope of protection of the invention is not limited to the embodiments, and any modification made by those skilled in the art within the scope defined by the claims also falls within the scope of protection of the invention.

As shown in fig. 1, a poly-generation system of heat, power and hydrogen for improving the flexibility of a thermoelectric power unit comprises a water electrolysis hydrogen production subsystem, a steam turbine generator subsystem and a steam extraction heat supply subsystem which are connected with each other.

As shown in FIG. 2, the water electrolysis hydrogen production subsystem comprises an electrolysis bath 9, a separation scrubber 12, an alkali liquor cooler 14, an alkali liquor circulating pump 8, a filter 13, a hydrogen storage tank 15, an AC/DC converter 7, a raw material water tank 10 and a water replenishing pump 11.

The AC/DC converter 7 is connected into an electrolytic bath 9, and the outlet of the electrolytic bath 9 is connected with the inlet of a separation scrubber 12; the raw material water tank 10 is connected with a separation washer 12 through a water replenishing pump 11; the liquid outlet of the separation scrubber 12 is connected with a filter 13, and the gas outlet of the separation scrubber 12 is connected with a hydrogen storage tank 15; the filter 13 is communicated with the inlet of the electrolytic cell through an alkali liquor cooler 14 and an alkali liquor circulating pump 8.

As shown in fig. 3, the steam turbine generator subsystem includes a steam turbine generator subsystem including a steam turbine 1, a generator 2, a transformer bank 3, a condenser 4, a steam extraction heat recovery system 6 and a condensate pump 5.

The steam turbine is conventional equipment in the field, and specifically comprises a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder which are sequentially connected through a steam pipeline; the generator 2 is directly driven by the steam turbine 1 and is connected with the inlet of the AC/DC converter 7 and the power grid side inlet of the transformer bank 3, and the generator 2 supplies power to an external power grid and the AC/DC converter 7 through the transformer bank 3; and low-pressure steam (dead steam) output from a steam outlet of a low-pressure cylinder of the steam turbine 1 is condensed by a condenser 4 and then is sent to a steam extraction heat recovery system 6 by a condensate pump 5.

As shown in fig. 4, the steam extraction and heat supply subsystem includes a heat supply regulating valve 18, a heating network heater 17 and a drain pump 16.

The heat supply extraction outlet of the steam turbine 1 is connected with the steam side inlet of the heat supply network heater 17 through a heat supply adjusting valve 18, and the steam side outlet of the heat supply network heater 17 is connected with the extraction steam heat recovery system 6 through a drain pump 16.

The condensate water pump 5 sends the condensate water into the steam extraction heat recovery system 6, and the condensate water is heated and pressurized and then is conveyed to the boiler to generate main steam, and the main steam drives the steam turbine 1 to operate.

The raw water tank 10 and the condensate pump 5 are respectively connected with a chemical water production system of the power plant indirectly.

The electrolytic cell 9 is filled with an aqueous solution of potassium hydroxide or sodium hydroxide with the mass fraction of 20-30%. The working temperature of the electrolytic cell 9 is 80-85 ℃.

And the water inlet and outlet of the heat supply network heater 17 are respectively connected with a cold and hot water pipeline of heat supply network circulating water. The heat supply network heater 17 is a shell-and-tube heat exchanger.

The working mode of the invention is as follows:

the invention mainly comprises 3 circulation processes, namely, a coal-fired boiler steam-turbine power generation circulation process; a steam extraction and heat supply circulation process of the steam turbine; and thirdly, a circulation process of hydrogen production by electrolyzing water. And the three processes are mutually coupled and supplemented, so that surplus electric power of the unit is absorbed, and the operation flexibility is improved.

The power generation cycle process of the steam supply turbine of the coal-fired boiler comprises the following steps: the steam turbine 1 is driven by superheated steam provided by a boiler, the steam expands in a high-pressure cylinder, a medium-pressure cylinder and a low-pressure cylinder which are sequentially connected to do work, a generator 2 is driven to generate electricity, part of generated electricity is sent into an external power grid through a transformer bank 3, and part of generated electricity enters a hydrogen production circulation process of electrolyzed water through an AC/DC converter 7; exhausted steam discharged by the steam turbine enters a condenser 4 to be condensed into water, the water is sent to a steam extraction heat recovery system 6 by a condensate pump 5, the steam extracted by the steam turbine 1 is used by the steam extraction heat recovery system 6, low-temperature condensate water is heated to high temperature by a series of heaters, and the low-pressure condensate water is pressurized by a water feed pump and then is conveyed to a boiler.

Steam extraction and heat supply circulation processes of a steam turbine: the heat supply extraction steam source is from a steam turbine 1, and a heat supply regulating valve 18 is responsible for controlling the flow and parameters of steam entering a heat supply network heater 17; the heat supply network heater 17 is a shell-and-tube heat exchanger, the heat supply steam enters the shell side, the heat supply network circulating water at the tube side is heated to the required temperature to meet the heat supply user, the inlet and the outlet at the tube side are respectively connected with the cold and hot water pipelines of the heat supply network circulating water, and the outlet at the shell side is connected with the drain pump 16; the drain pump 16 pumps the heat supply network heater into the pipeline of the steam extraction heat recovery system 6 after draining and pressurizing.

The circulation process of hydrogen production by water electrolysis: the alternating current generated by the generator 2 or coming from an external power grid through the transformer bank 3 is converted into direct current through the AC/DC converter 7 and enters the electrolytic cell 9; the electrolytic bath 9 is filled with alkali liquor in which potassium hydroxide or sodium hydroxide is dissolved, water in the alkali liquor is decomposed into hydrogen and oxygen under the action of direct current, and the hydrogen and oxygen are respectively fed into a hydrogen and oxygen separation washer 12 in the frame together with the alkali liquor to be subjected to gas-liquid separation, washing and cooling, and the separated alkali liquor is mixed with supplemented pure water and then returns to the electrolytic bath 9 through a filter 13, an alkali liquor cooler 14 and an alkali liquor circulating pump 8; the separated hydrogen is sent into a hydrogen storage tank 15, and is buffered and decompressed for users to use; the alkali liquor cooler 14 controls the temperature of the returned alkali liquor to control the working temperature of the electrolytic bath 9, so that the system can run safely; soft water in the raw water tank 10 comes from a chemical water production system of a power plant and enters a separation scrubber 12 through a water replenishing pump 11 to replenish water consumed by electrolysis.

According to coulomb's law, gas production is proportional to current, independent of other factors. The power consumption of unit gas output depends on the electrolytic voltage, the higher the working temperature of the electrolytic cell is, the lower the electrolytic voltage is, and the corrosion to the electrolytic cell material, mainly the diaphragm material, is increased, and the operating temperature is preferably selected to be 80-85 ℃. The choice of electrolysis voltage depends mainly on the need for hydrogen. The gas purity is determined by the hydrogen generator configuration and operation. The purity is stable under conditions of normal operating pressure (mainly normal differential pressure control) with intact equipment (mainly no damage to the cell membrane).

The advantage of the invention in terms of flexibility is illustrated.

The calculation formula of the internet surfing electric quantity of the system is as follows:

P_n＝P_f-P_h-P_s (1)

in the formula, P_nFor the amount of power available for Internet access, P_fGenerated by the generator 2, P_hThe power consumption P of the system for producing hydrogen by electrolyzing water_sThe power consumption of the plant (the power consumption of hydrogen production by water electrolysis is not included).

When the unit is in the non-heating period, P_fThe lowest value depends on the lowest stable combustion load of the boiler, and is P_{f min1}Is represented by P_fThe highest value is the maximum output designed for the generator 2, in P_{f max1}And (4) showing.

When the unit is in the heating period,P_fthe lowest value is the current heat supply steam extraction quantity D_rMinimum output of the generator 2, in P_{f min}(D_r) Is represented by P_fThe highest value is the current heat supply D_rMaximum output of the generator 2 in P_{f max}(D_r) And (4) showing. P_{f min}(D_r)、P_{f max}(D_r) And the heat supply steam extraction quantity D_rIs provided by the manufacturer of the steam turbine 1.

P_hThe power consumption of the water electrolysis hydrogen production system can be flexibly adjusted according to the conditions of a power grid and a heat supply network. Its lowest value may be zero and its highest value is its designed maximum output, expressed as P_{h max}And (4) showing.

P_sThe power consumption of the plant is the power consumption, the power consumption of hydrogen production by water electrolysis is not included, and the parameter is related to the current running state of the unit.

From the above, when the unit is in the non-heating period, the power P of the upper network is provided_nThe maximum adjustable range of (d) is expressed as follows:

(P_{f min1}-P_hmax-P_s)≤P_n≤(P_{f max}-P_s) (2)

when the unit is in the heating period, the on-line electricity quantity P is_nThe maximum adjustable range of (d) is expressed as follows:

[P_{f min}(D_r)-P_hmax-P_s]≤P_n≤[P_{f max}(D_r)-P_s] (3)

as can be seen from the formulas (2) and (3), the designed maximum output P of the water electrolysis hydrogen production system is reasonably selected_{h max}The on-line electricity quantity P can be obviously increased in both the heating period and the non-heating period_nThe adjustment range of the air conditioner enables the flexibility of the air conditioner set to be greatly improved.

In addition, the operation adjustment of the water electrolysis hydrogen production system is extremely quick and can be flexibly adjusted according to the conditions of a power grid and a heat supply network. The hydrogen production can be changed by adjusting the current level in the electrolytic cell 9 or shutting down/operating a part of the electrolytic cell within a permissible range. The method can quickly and frequently adjust the output of the water electrolysis hydrogen production subsystem, timely respond to the requirements of a power grid and a heat supply network, and further improve the flexibility of the unit.

The economic advantage of the present invention is illustrated.

The income of the thermoelectric power unit mainly comprises electricity selling income, heat supply income and power grid auxiliary service income (depending on the implementation rules of grid-connected power plant auxiliary service management of each place).

The invention can make the thermoelectric unit operate in high load and high efficiency state for a long time, and convert the surplus electric power into high-quality and high-price energy of high-purity hydrogen. The unit adopting the invention increases the income of hydrogen production by water electrolysis.

When the heat supply of the unit adopting the invention is the same as that of the common thermoelectric unit, the benefits of the two are compared from two typical working conditions.

The first operating condition is as follows.

Compared with the common thermoelectric unit, the calculation formula of the profit difference under the same on-line electricity quantity and heat supply quantity is as follows:

C_d＝(C_fd+C_rd+C_hd-C_cd+C_wd)-(C_ft+C_rt-C_ct+C_wt) (4)

in the formula, C_dTo make a poor profit, C_ftAnd C_fdRespectively, a common thermoelectric unit and a thermoelectric unit adopting the invention for selling electricity income, C_rtAnd C_rdRespectively, the heat supply income of the common thermoelectric unit and the thermoelectric unit adopting the invention, C_ctAnd C_cdThe power generation costs of the conventional thermoelectric power unit and the thermoelectric power unit using the present invention, respectively, C_hdIncome for hydrogen production by water electrolysis C_wtAnd C_wdThe auxiliary service income of the power grid of the common thermoelectric unit and the thermoelectric unit adopting the invention is respectively taken.

Under the same on-line electricity quantity, C_ftAnd C_fdBoth are equal and heat supply is the same, C_rtAnd C_rdBoth are equal. According to the 'auxiliary service management implementation rule of grid-connected power plant' of each place, the auxiliary service income C of the power grid_wtAnd C_wdThe value of (A) is mainly determined by the power on the Internet (two machines)The same price per unit of electricity for the group). Therefore, equation (4) is simplified to:

C_d＝C_hd+C_ct-C_cd (5)

the power generation cost of the thermoelectric power unit is mainly fuel cost, and the level of the power generation cost is determined by the power output and the heat efficiency of the boiler and the steam turbine 1. C_ctAnd C_cdRepresented by the formula:

C_ct＝C_p×P_ft×η_t (6)

C_cd＝C_p×P_fd×η_d＝C_p×(P_ft+P_hd)×η_d (7)

in the formula, under the same on-line electricity quantity and heat supply quantity, P_ftAnd P_fdThe output, eta, of the generator 2 of the common thermoelectric unit and the thermoelectric unit adopting the invention_tAnd η_dRespectively the coal consumption rate, C of the common thermoelectric unit and the thermoelectric unit adopting the invention_pIs the coal price per unit mass.

Substituting the formulas (6) and (7) into the formula (5) to obtain:

C_cd＝(C_hd-C_p×P_hd×η_d)+C_p×P_ft×(η_t-η_d) (8)

because of the existence of the circulation flow of hydrogen production by water electrolysis, under the same on-line electricity quantity and heat supply quantity, the output and heat efficiency of the boiler and the steam turbine are higher than those of the common unit by adopting the thermoelectric unit after the invention, and the coal consumption rate eta is higher_tIs higher than eta_d. Income of circulation flow for producing hydrogen by electrolyzing water C_hdAnd cost C_p×P_hd×η_dThe balance is kept, and the benefit of the thermoelectric unit adopting the thermoelectric power generation device is higher than that of the common thermoelectric unit as shown in the formula (8).

The second condition is as follows.

Compared with the common thermoelectric unit, the unit adopting the invention has the advantages that under the condition that the output of the generator 2 is the same as the heat supply of the unit, the calculation formula of the profit difference is the same as the formula (4):

C_d＝(C_fd+C_rd+C_hd-C_cd+C_wd)-(C_ft+C_rt-C_ct+C_wt) (9)

in the above formula, the parameter definitions are also the same as those of formula (4). Heat supply income C of two units under the same heat supply_rtAnd C_rdEqual; meanwhile, because the output of the generator 2 is equal, the main steam flow of the generator and the main steam flow of the turbine can be considered to be equal, and the output and the heat efficiency of the boiler and the steam turbine are also equal, so the power generation cost C of the two units is equal_ctAnd C_cdAre equal. Equation (9) can be simplified as:

C_d＝(C_fd-C_ft)+(C_wd-C_wt)+C_hd (10)

the generating income of the thermoelectric generator set depends on the on-line electric quantity and the on-line electricity price. Thus, C_ftAnd C_fdCan be represented by the following formula:

C_ft＝C_dj×P_nft (11)

C_fd＝C_dj×P_nfd＝C_dj×(P_nft-P_hd) (12)

in the formula, P is the power and heat supply of the same generator 2_nftAnd P_nfdThe electric quantity of the common thermoelectric unit and the thermoelectric unit adopting the invention on the internet, P_hdThe power consumption of the system for producing hydrogen by electrolyzing water, C_djThe price of the power is the price of the power on the internet.

Substituting formulae (11) and (12) for formula (10) to obtain:

C_d＝(C_hd-C_dj×P_hd)+(C_wd-C_wt)＝(C_hj×P_hd-C_dj×P_hd)+(C_wd-C_wt) (13)

in the formula, C_djThe price of hydrogen produced per unit of electrical energy.

Grid ancillary services revenue C_wtAnd C_wdThe value of the peak load is mainly determined by the power on the Internet (the price per unit of power of the two units is the same), the power on the Internet of the thermoelectric unit is lower after the thermoelectric unit is adopted, and more peak load regulation auxiliary service compensation can be obtained compared with the common thermoelectric unitAnd (6) income. As can be seen from formula (13), the price C of hydrogen produced per unit of electric energy_hjAnd the on-line electricity price C_djThe yield of the thermoelectric unit adopting the invention is higher than that of the common thermoelectric unit.

In a word, when the heat supply amount is equal, the income of the thermoelectric generator set adopting the invention is higher than that of the common thermoelectric generator set no matter the on-grid electricity amount is the same or the output of the generator 2 is the same, and the thermoelectric generator set has better economy.

The invention relates to a heat, power and hydrogen poly-generation system for improving the flexibility of a thermoelectric unit, which realizes the coupling, the cooperation and the flexible operation of a plurality of systems and improves the energy efficiency. Compared with the prior art, the method has the characteristics of less investment, guaranteed safety, convenient and quick operation adjustment, large peak regulation range and small influence on the operation heat economy of the unit. The thermoelectric generator set can be configured on thermoelectric generator sets with different capacities, and has a certain application prospect.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.