Power plant peak shaving steam and water dual heat supply system

Abstract

The application discloses a power plant peak-shaving steam heat storage type steam-water dual-purpose heat supply system, which comprises a group of boiler modules, a power plant steam leading-out pipe, a boiler water supply and discharge pipe, a heat storage condensate water pipe, a heat releasing water supply pipe, a steam-water separator, a boiler steam pipe, a heat releasing steam pipe and a superheated steam pipe; the boiler modules are connected with the outlet end of the power plant steam leading-out pipe, so that the power plant heat storage steam is introduced into the boiler modules; heat storage materials are arranged in the boiler modules; the heat storage steam enters the boiler modules, stores heat in the heat storage materials and is condensed, and the generated condensate water is sequentially sent into an energy storage water tank of the power plant through the boiler water supply and discharge pipe and the heat storage condensate water pipe; the boiler water supply and discharge pipe is also connected to a shunt mixed water pipe of the power plant through the heat releasing water supply pipe, so that the cold water in the power plant is sent into the boiler modules through a pressure pump, the heat energy in the heat storage materials is converted into steam, and then the steam is sent into the steam-water separator or the superheated steam pipe through the boiler steam pipe, so as to be used by the power plant.

Description

TECHNICAL FIELD

[0001] The present application relates to the power plant peak shaving industry, in particular to the power plant steam energy storage peak shaving technical field, and particularly relates to a power plant peak shaving steam heat storage type steam and water dual-purpose heating system. BACKGROUND

[0002] The operation of various clean energy is steadily advancing, and the proportion of total energy consumption is also steadily increasing year by year. The demand for power plant peak shaving power is also gradually increasing. Compared with clean energy and other power sources, coal power has better peak shaving performance. Therefore, the demand for peak shaving of coal power plants is increasing year by year, and the flexibility of coal power is imperative.

[0003] The existing power plant peak shaving measures in China are relatively few, mainly including the following ways: (1) relying on the load adjustment system of the power plant itself to deeply tap the potential, but the adjustment capacity of the power plant itself obviously cannot meet the adjustment demand of the power grid for load during peak and valley periods, and with the increase of the load adjustment range of the power plant itself, the "safe operation" risk of the equipment system of the power plant is significantly increased. (2) Increasing the demand for heating load and the supply of industrial steam during the heating season, and implementing measures such as "electricity determined by heat". This measure obviously has a "seasonal influence" factor, especially in the southern region where the heating season is short or no heating is needed. This problem is particularly prominent. (3) Promote the support of power consumption during the power grid peak shaving period, and various mechanical energy storage, electrochemical energy storage, heat storage type electric boiler, heat storage water tank and other products developed therefrom. Such products are generally suitable for areas with industrial and civil heating needs, and also have seasonal demand problems. Especially the heat storage water tank, the "grade reduction" of the stored energy is large, and in terms of energy conversion, it also basically needs to use high-grade electric energy for storage and release.

[0004] The above measures all play a certain positive role in the demand for power plant peak shaving. However, they all have obvious shortcomings and still have a large gap relative to the demand for power plant peak shaving. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a power plant peak shaving steam ladder energy storage steam and water dual-purpose heating system, which integrates "heat storage function" and "boiler function" to solve the "storage and release" of the "load" of the power plant peak shaving.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] The utility model provides a kind of power plant peak shaving steam heat storage type steam and water dual-purpose heating system, including a group of boiler module, power plant steam lead-out pipe, boiler feed and drain pipe, heat storage condensate pipe, heat-releasing feedwater pipe, superheated steam pipe, steam-water separator, boiler steam pipe, heat-releasing steam pipe and superheated steam pipe;

[0008] The boiler module is connected with the outlet end of the power plant steam lead-out pipe, and the heat storage steam of the power plant is introduced into the boiler module; The boiler module is provided with heat storage materials, and the heat storage steam enters the boiler module to store heat in the heat storage materials and condenses, and the generated condensate is sequentially sent into the energy storage water tank of the power plant through the boiler feed and drain pipe and the heat storage condensate pipe.

[0009] The boiler feed and drain pipe is also connected to the shunt mixed water pipe of the power plant through the heat-releasing feedwater pipe, and the cold water in the power plant is sent into the boiler module, and the heat energy in the heat storage materials is converted into steam, and is collected to the boiler steam pipe; The boiler steam pipe is connected to the superheated steam pipe and the steam-water separator through a tee pipe.

[0010] The steam generated in the boiler module is sent into the steam-water separator through the boiler steam pipe for gas-liquid separation, and the hot steam is sent into the power plant for unified use through the heat-releasing steam pipe.

[0011] One end of the superheated steam pipe is connected to the boiler steam pipe, and the other end is connected to the steam inlet of the low-pressure cylinder of the power plant, and the superheated steam generated by the boiler module is directly used for power generation.

[0012] Further, the heat-releasing feedwater pipe is also connected to the steam-water separator through a branch pipe, and the cold water in the power plant is sent into the steam-water separator to mix and heat with the steam from the boiler module, and the generated hot water is sent into the shunt mixed water pipe of the power plant through the heat-releasing hot water pipe to preheat the boiler feedwater of the power plant.

[0013] Specifically, the boiler module includes a group of boilers connected in series through communication pipes; Each boiler is filled with heat storage materials; One end of the communication pipe is connected to the bottom of the previous boiler, and the other end is connected to the top of the next boiler; Each boiler is connected to the heat storage condensate pipe and the heat-releasing feedwater pipe through the respective boiler feed and drain pipe.

[0014] Specifically, the boiler feed and drain pipe includes two branch pipes connected to the heat storage condensate pipe and the heat-releasing feedwater pipe, respectively; The branch pipe connected to the heat storage condensate pipe is provided with a condensate valve and a trap, and the branch pipe connected to the heat-releasing feedwater pipe is provided with a feedwater regulating valve.

[0015] Specifically, the boiler steam pipe is connected to each boiler through a branch pipe, and each branch pipe is provided with a steam communication valve, and the boiler steam pipe is provided with a boiler module steam communication valve and a steam supply main valve.

[0016] Specifically, the power plant steam lead-out pipe is sequentially provided with a heat storage steam valve and a main steam valve.

[0017] Specifically, the heat storage condensate pipe is sequentially provided with a flow meter, a condensate total valve and a condensate pressurizing pump.

[0018] Specifically, the heat release feedwater pipe is sequentially provided with a pressurizing pump and a heat release feedwater total valve.

[0019] Specifically, the heat release steam pipe is sequentially provided with a pressure gauge and a heat release total steam valve; and the superheated steam pipe is provided with a superheated steam valve.

[0020] Further, a liquid level regulating valve is arranged on a branch pipe connected with the steam-water separator of the heat release feedwater pipe; a liquid level gauge is arranged on the steam-water separator; and a heat release hot water total valve is arranged on the heat release hot water pipe.

[0021] Beneficial effects:

[0022] (1) The system is especially suitable for steam energy storage peak shaving, and can be used in industrial and enterprise units with similar requirements. The main function is to store and release steam and hot water, and the comprehensive energy conversion efficiency in the conversion of steam and hot water storage and release can reach 80-90%.

[0023] (2) The system adopts a steam ladder energy storage heating mode, which has high energy conversion efficiency, more than 1 times higher than the traditional electric energy storage efficiency, reduces the process of converting steam heat energy into electric energy, and realizes modular production of steam energy storage steam boilers, achieving efficient and large-capacity storage and transfer of steam peak load of power plants. It can effectively alleviate the influence of safety operation, seasonal influence and grade reduction of existing power plant peak shaving measures. The phase change material of steam energy storage operates at normal pressure, and the heat storage material does not produce the operation safety hidden danger caused by hardening and solidification, is efficient and pollution-free. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and / or other aspects of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1 is a schematic diagram of the overall system flow of the heating system.

[0026] Figure 2 is an enlarged view of the local structure of the steam-water separator in the overall system of the heating system.

[0027] Figure 3 is a schematic diagram of the overall system flow of the heating system connected with the power plant.

[0028] In the drawings, various reference numerals represent:

[0029] 1. Thermal storage steam valve; 2. Main steam valve; 3. Condensate switch valve; 4. Condensate main valve; 5. Heat release feedwater main valve; 6. Steam main valve; 7. Heat release main steam valve; 8. Heat release hot water main valve; 9. Boiler module steam connection valve; 10. Steam connection valve; 11. Boiler module; 12. Feedwater regulating valve; 13. Steam trap; 14. Flow meter; 15. Liquid level regulating valve; 16. Liquid level gauge; 17. Steam-water separator; 18. Pressure gauge; 19. Connecting pipe; 20. Power plant steam outlet pipe; 21. Diverting mixing pipe; 22. Energy storage water tank; 23. Boiler pressurization pump; 24. Boiler feedwater pipe; 25. Thermal storage condensate pipe; 26. Heat release feedwater pipe; 27. Boiler steam pipe; 28. Heat release steam pipe; 29. ​​Heat release hot water pipe; 30. Condensate pressurization pump; 31. Superheated steam pipe; 32. Superheated steam valve. Detailed Implementation

[0030] The present invention can be better understood from the following embodiments.

[0031] like Figure 1 (Detailed enlarged view) to Figure 3 As shown in the overall system diagram, the power plant's peak-shaving steam storage dual-use steam and water heating system includes a set of boiler modules 11, power plant steam outlet pipes 20, boiler feedwater pipes 24, thermal storage condensate pipes 25, heat release feedwater pipes 26, steam-water separators 17, boiler steam pipes 27, heat release steam pipes 28, and superheated steam pipes 31.

[0032] The boiler module 11 is connected to the outlet end of the power plant steam outlet pipe 20, which introduces the power plant's heat storage steam into the boiler module 11. The boiler module 11 is equipped with heat storage material. When the heat storage steam enters the boiler module 11, it stores heat in the heat storage material and condenses. The resulting condensate is sent to the power plant's energy storage tank 22 through the boiler feed and drain pipe 24 and the heat storage condensate pipe 25. The heat storage condensate pipe 25 is equipped with a condensate pressurization pump 30, which is a backup pump used when the condensate return to the energy storage tank is obstructed.

[0033] The boiler feedwater pipe 24 is also connected to the power plant’s diversion mixing pipe 21 via the heat release water pipe 26, which sends cold water from the power plant into the boiler module 11 via the booster pump 23, and converts the heat energy in the heat storage material into steam, which is then collected into the boiler steam pipe 27. The boiler steam pipe 27 is connected to the superheated steam pipe 31 and the steam-water separator 17 via a tee pipe.

[0034] The steam generated in the boiler module 11 is sent to the steam-water separator 17 through the boiler steam pipe 27 for gas-liquid separation, and the hot steam is sent to the power plant for overall use through the heat release steam pipe 28.

[0035] One end of the superheated steam pipe 31 is connected to the boiler steam pipe 27, and the other end is connected to the steam inlet of the low-pressure cylinder of the power plant, so that the superheated steam generated by the boiler module 11 can be directly used for power generation.

[0036] The heat-releasing feedwater pipe 26 is also connected to the steam-water separator 17 through a branch pipe, and the cold water in the power plant is sent into the steam-water separator 17 to mix and heat with the steam from the boiler module 11, and the generated hot water is sent into the branch mixed water pipe 21 of the power plant through the heat-releasing hot water pipe 29 to preheat the boiler feedwater of the power plant.

[0037] The boiler module 11 comprises a group of boilers connected in series through Z-shaped vertical communication pipes 19; each boiler is filled with heat storage material; one end of the communication pipe 19 is connected to the bottom of the previous boiler, and the other end is connected to the top of the next boiler; each boiler is connected to the heat storage condensate pipe 25 and the heat-releasing feedwater pipe 26 through the respective boiler feed and drain pipe 24. The function of the communication pipe 19 is to realize step-by-step heat exchange energy storage in the steam storage boiler module in the heat storage stage, and to realize steam supply in the steam storage heat exchange module to achieve automatic overflow of the steam collection header to supply water to the lower water collection tank of the next boiler module after the water in the steam supply header is full in the heat supply stage. It also realizes the function of connecting and heating to maximize the heat storage capacity of the phase change heat storage material in each boiler module.

[0038] The boiler feed and drain pipe 24 comprises two branch pipes connected to the heat storage condensate pipe 25 and the heat-releasing feedwater pipe 26, respectively; the branch pipe connected to the heat storage condensate pipe 25 is provided with a condensate switch valve 3 and a trap 13, and the branch pipe connected to the heat-releasing feedwater pipe 26 is provided with a feedwater regulating valve 12.

[0039] The boiler steam pipe 27 is connected to each boiler through a branch pipe, and each branch pipe is provided with a steam communication valve 10; the boiler steam pipe 27 is provided with a boiler module steam communication valve 9 and a steam supply main valve 6. Each steam boiler can independently produce steam, and two or more boilers can be combined in series or parallel to produce steam simultaneously, that is, each boiler module is provided with an independent feedwater and steam supply branch pipe system. The function of flexible operation control in the "heat supply stage" is realized.

[0040] The heat-releasing steam pipe 28 is provided with a pressure gauge 18 and a heat-releasing total steam valve 7 in sequence.

[0041] The heat storage condensate pipe 25 is provided with a flow meter 14, a condensate total valve 4 and a condensate pressurizing pump 30 in sequence.

[0042] The heat-releasing feedwater pipe 26 is provided with a pressurizing pump 23 and a heat-releasing feedwater total valve 5 in sequence.

[0043] The heat-releasing steam pipe 28 is provided with a pressure gauge 18 and a heat-releasing total steam valve 7 in sequence.

[0044] The superheated steam pipe 31 is provided with a superheated steam valve 32.

[0045] The heat releasing water pipe 26 is connected with the branch pipe of the steam-water separator 17, and is provided with a liquid level adjusting valve 15; the steam-water separator 17 is provided with a liquid level gauge 16; and the heat releasing hot water pipe 29 is provided with a heat releasing hot water total valve 8. The steam-water separator 17 ensures that the saturated steam under a given condition is outputted to the outside, and also can stably output hot water under a saturated temperature to the outside. The liquid level gauge 16 is used to stabilize the liquid level in the steam-water separator 17 within a given fluctuation range by adjusting the liquid level adjusting valve 15, so as to ensure that the system can stably supply heat to the outside.

[0046] The steam step energy storage heating system is suitable for peak shaving steam energy storage heating of power plants, and is also suitable for energy storage and heating of other industrial waste heat steam. The working principle of the steam energy storage heating system is shown in Figure 2

[0047] The implementation operation process is divided into two stages. One is a "heat storage stage", which receives and stores the high-temperature steam branched during power plant peak shaving. The other is a "heating stage", which releases the heat stored in the steam boiler module in the form of "superheated steam" along the original path to the superheated steam pipe for power generation or to the steam-water separator, and realizes the given function of supplying saturated steam and hot water to the outside in the steam-water separator. When the heat stored in the boiler is released, a "heat storage and heating" cycle is completed. The working principle processes of the two operation stages are described as follows:

[0048] (1) Working principle process of "heat storage stage":

[0049] All valves in the system device are in the closed state at the initial state. After receiving the energy storage and heat storage start instruction, the system will sequentially open the heat storage steam valve 1, the main steam valve 2, the condensate switch valve 3, the condensate total valve 4, the electric valve of the condensate inlet valve of the power plant energy storage water tank 22, and the high-temperature steam will sequentially enter the series-connected steam energy storage steam boiler and convert and store the steam energy in the boiler heat storage module. The heat-released steam is converted into condensate water, which is discharged to the power plant energy storage water tank system under the action of steam pressure. When the condensate water return to the energy storage water pipe is not smooth, the condensate water booster pump 30 can be started to forcibly drain water. During the heat storage process, the high-temperature steam sequentially passes through three (or more) energy storage boilers for energy storage and heat exchange. Each boiler is connected in series through the communication pipe 19 to form a step heat exchange. The energy storage and heat exchange end is confirmed according to the given parameters of the flow meter 14 and the heat exchange time. Thus, the energy storage and heat exchange process of the "heat storage stage" is completed.

[0050] (2) Working principle process of "heating stage":

[0051] ​All the valves in the system device are in the closed state in the initial state, after receiving the start heat release instruction, the system will open the heat release feedwater main valve 5, the main steam valve 2, the steam supply main valve 6, the heat release main steam valve 7 and the power plant booster pump 23 in turn. At this time, the feedwater regulating valve 12 will automatically open the steam to the boiler feedwater to increase the pressure until the steam pressure reaches the given parameter, and then the operation mode of automatically generating the given steam parameter is converted, and the superheated steam for power generation or the saturated steam and hot water output through the steam-water separator is output, it should be noted that the lower part of each energy storage evaporation boiler is equipped with a water delivery and feedwater pipeline, and in actual operation, it should be used according to the demand and the safe operation condition (three modules can be combined into series or parallel mode operation). When hot water is needed: according to the given condition instruction, open the heat release hot water main valve 8, output hot water, and the liquid level regulating valve 15 will automatically open and balance the liquid level in the steam-water separator 17 to ensure the continuous and stable output of the system.

[0052] After passing through the "heat storage stage" and "heat supply stage" two processes, the steam ladder energy storage type steam and water dual-purpose system device for power plant peak shaving completes a complete steam energy storage and heat supply cycle (one ladder heat storage and heat release cycle period corresponds to one power plant peak shaving period).

[0053] The application provides a kind of steam heat storage type steam and water dual-purpose heat supply system for power plant peak shaving, and there are many methods and ways to realize the technical scheme, and the above description is only preferred embodiment of the present application, it should be pointed out that, for ordinary skilled person in the art, without departing from the principle of the present application, a number of improvements and refinements can be made, these improvements and refinements should also be considered as the protection scope of the present application. The components not explicitly described in the embodiment can be realized by existing technology.

Claims

1. A steam and water dual heat supply system for power plant peak shaving and steam accumulation, characterized in that, The boiler module (11), the power plant steam outlet pipe (20), the boiler water supply and drainage pipe (24), the heat storage condensate pipe (25), the heat release water pipe (26), the steam-water separator (17), the boiler steam pipe (27), the heat release steam pipe (28) and the superheated steam pipe (31); The boiler module (11) is connected with the outlet end of the power plant steam outlet pipe (20), and the heat storage steam of the power plant is introduced into the boiler module (11); the boiler module (11) is provided with heat storage materials, the heat storage steam enters the boiler module (11) to store heat in the heat storage materials and condenses, and the generated condensate water is sequentially sent into the energy storage water tank (22) of the power plant through the boiler water supply and drainage pipe (24) and the heat storage condensate pipe (25); The boiler water supply and drainage pipe (24) is further connected to the power plant shunt mixed water pipe (21) through the heat release water pipe (26), and the cold water in the power plant is sent into the boiler module (11), heated into steam by the heat energy in the heat storage materials, and collected to the boiler steam pipe (27); the boiler steam pipe (27) is connected to the superheated steam pipe (31) and the steam-water separator (17) through a three-way pipe; The steam generated in the boiler module (11) is sent into the steam-water separator (17) through the boiler steam pipe (27) to perform gas-liquid separation, and the hot steam is sent into the power plant for unified use through the heat release steam pipe (28); One end of the superheated steam pipe (31) is connected to the boiler steam pipe (27), and the other end is connected to the steam inlet of the low-pressure cylinder of the power plant, so that the superheated steam generated by the boiler module (11) is directly used for power generation; The heat release water pipe (26) is further connected to the steam-water separator (17) through a branch pipe, and the cold water in the power plant is sent into the steam-water separator (17) to be mixed and heated with the steam from the boiler module (11), and the generated hot water is sent into the shunt mixed water pipe (21) of the power plant through the heat release hot water pipe (29) to preheat the boiler feed water of the power plant; The boiler module (11) comprises a plurality of boilers connected in series through communication pipes (19); each boiler is filled with heat storage materials; one end of the communication pipe (19) is connected to the bottom of the previous boiler, and the other end is connected to the top of the next boiler; each boiler is connected to the heat storage condensate pipe (25) and the heat release water pipe (26) through the respective boiler water supply and drainage pipe (24).

2. The system according to claim 1, wherein, The boiler water supply and drainage pipe (24) comprises two branch pipes connected to the heat storage condensate pipe (25) and the heat release water pipe (26), respectively; the branch pipe connected to the heat storage condensate pipe (25) is provided with a condensate switch valve (3) and a trap (13), and the branch pipe connected to the heat release water pipe (26) is provided with a feed water regulating valve (12).

3. The system according to claim 1, wherein, The boiler steam pipe (27) is connected to each boiler through branch pipes, respectively; each branch pipe is provided with a steam communication valve (10), and the boiler steam pipe (27) is provided with a boiler module steam communication valve (9) and a steam supply main valve (6).

4. The system according to claim 1, wherein, The power plant steam outlet pipe (20) is sequentially provided with a heat storage steam valve (1) and a main steam valve (2).

5. The system according to claim 1, wherein, The heat storage condensate pipe (25) is sequentially provided with a flow meter (14), a condensate total valve (4) and a condensate pressure pump (30).

6. The system according to claim 1, wherein, The heat releasing feed water pipe (26) is sequentially provided with a pressure pump (23) and a heat releasing feed water total valve (5).

7. The system according to claim 1, wherein, The heat releasing steam pipe (28) is sequentially provided with a pressure gauge (18) and a heat releasing total steam valve (7); and the superheated steam pipe (31) is provided with a superheated steam valve (32).

8. The system according to claim 1, wherein, A liquid level adjusting valve (15) is arranged on a branch pipe connected between the heat releasing feed water pipe (26) and a steam-water separator (17); the steam-water separator (17) is provided with a liquid level gauge (16); and the heat releasing hot water pipe (29) is provided with a heat releasing hot water total valve (8).

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