A new type of heat storage heat exchanger system

Abstract

A novel heat storage heat exchanger system includes a boiler. The outlet of the boiler is connected to a superheater, and steam enters the main steam pipeline, passing through a steam turbine, a condenser, a condensate pump, a condensate tank, a low-pressure heater, a deaerator, a feed pump, a high-pressure heater, and an economizer before entering the boiler. The present invention is applicable to occasions with large day-night load fluctuations. By means of a high-pressure steam accumulator and a low-pressure steam accumulator, steam of different grades is stored. In occasions with large differences in user load demands, the load fluctuations of the boiler are reduced, enabling the boiler to always operate at a relatively high efficiency. The application of automatic regulating valves reduces the frequent actions caused by fluctuations, which is of great significance for energy conservation and achieving energy-saving and carbon-reduction of the system.

Description

Technical Field

[0001] The present invention belongs to the field of industrial and civil heat accumulators, and relates to a cogeneration system applied to large fluctuations in steam consumption load and large instantaneous steam consumption, and specifically to a novel heat storage heat exchanger system. Background Art

[0002] In a thermal power plant system, electricity is generated while heating. The heating demand during the day and at night varies greatly, resulting in large fluctuations in steam consumption. The steam pressure and water pressure of the boiler also often fluctuate up and down, making the boiler operation difficult and the combustion efficiency low. Applying a heat accumulator can effectively stabilize the boiler load. When the load decreases, the boiler load is not reduced, so the combustion efficiency of the boiler is not reduced. Currently, there are two forms of heat accumulators. One is a steam heat accumulator, which belongs to a variable-pressure heat accumulator. When the boiler evaporation capacity is greater than the steam consumption, the excess steam enters the heat accumulator to heat the feed water therein, and the steam condenses in the heat accumulator, and the pressure of the heat accumulator rises. When the steam consumption is greater than the boiler evaporation capacity, the saturated water stored in the heat accumulator is depressurized to provide steam and keep the boiler load unchanged. The other is a feed water heat accumulator, which belongs to a constant-pressure heat accumulator. The pressure inside the heat accumulator remains unchanged, and the heat is absorbed and released by adjusting the change in the feed water volume.

[0003] Existing heat accumulators are usually used singly to provide steam with a single pressure, and there is still much room for improvement in the efficiency of the boiler, which cannot meet the needs of specific users for steam of different grades. Summary of the Invention

[0004] In view of the problem of uneven power generation and heat use in a thermal power plant, the present invention designs a novel heat storage heat exchanger system to meet the needs of heat uniformity and different steam grades, and at the same time improve the economic operation of the boiler.

[0005] The present invention is achieved by the following technical solutions:

[0006] A new type of heat storage heat exchanger system, including a boiler 1, a superheater 2, a main steam pipeline 3, a high-pressure steam accumulator 4, a desuperheating and pressure-reducing valve 5, a high-pressure heat user 6, a steam turbine 7, a generator 8, a condenser 9, a low-pressure steam accumulator 10, a low-pressure heat user 11, a condensate pump 12, a condensate tank 13, a low-pressure heater 14, a deaerator 15, a feed water pump 16, a high-pressure heater 17, a economizer 18, a feed water tank 19, a feed water pump 20, a feed water accumulator 21, and a feed water pump 22. The outlet of the boiler 1 is connected to the superheater 2, and the steam enters the main steam pipeline 3. Most of the steam performs work in the steam turbine 7 for power generation; another part of the steam stores heat through the variable-pressure high-pressure steam accumulator 4, and still another part goes to the high-pressure heat user 6 through the desuperheating and pressure-reducing valve 5. The steam that has performed work in the steam turbine passes through the condenser 9, and then successively passes through the condensate pump 12, the condensate tank 13, the low-pressure heater 14, the deaerator 15, the feed water pump 16, the high-pressure heater 17, and the economizer 18 and enters the boiler 1. Part of the steam entering the steam turbine 7 is sent to the low-pressure heat user 11, and the other part heats the feed water through the constant-pressure feed water accumulator 21.

[0007] The inlet end of the high-pressure steam accumulator 4 is connected to the main steam pipeline 3, and the outlet end is located after the desuperheating and pressure-reducing valve 5 and before the high-pressure heat user. Electric control valves are arranged at the inlet and outlet of the high-pressure steam accumulator 4. The inlet valve is located between the main steam pipeline 3 and the inlet of the high-pressure steam accumulator, and the outlet valve is located before the outlet of the high-pressure steam accumulator to the high-pressure heat user, so as to control the steam balance among the high-pressure accumulator, the power generation amount, and the heat user. The inlet end of the low-pressure steam accumulator 10 is connected to the extraction pipeline, and the outlet end is connected to the low-pressure heat user 11. Electric control valves are arranged at the inlet and outlet of the low-pressure steam accumulator 10. The inlet valve is located between the extraction pipeline and the inlet of the low-pressure steam accumulator, and the outlet valve is located before the low-pressure heat user. For the feed water accumulator 21, the makeup water is provided by the feed water tank 19, passes through the feed water pump 20 and the economizer 18, and enters the feed water accumulator 21. The extraction steam from the steam turbine 7 enters the feed water accumulator 21 to heat the feed water, and the heated feed water enters the boiler 1 through the feed water pump 22; another part is connected to the low-pressure heat user 11, and the return water finally reaches the boiler 1.

[0008] The beneficial effects of the present invention are:

[0009] (1) This device is applied to occasions with large fluctuations in day and night loads. While ensuring the power generation amount, through the combined use of the high-pressure steam accumulator and the low-pressure steam accumulator, in occasions with large differences in user load demands, the load fluctuation of the boiler is reduced, so that the boiler always operates at a relatively high efficiency, and the application of the automatic regulating valve reduces the frequent actions caused by the fluctuations;

[0010] (2) Store steam with different pressures for use by heat users with different demands.

[0011] (3) The combined use of steam accumulators and feedwater accumulators can increase the boiler efficiency under the condition of large load fluctuations, which is of great significance for energy conservation and achieving system energy conservation and carbon reduction. Description of the Drawings

[0012] Figure 1 It is the process flow diagram of a new type of heat storage heat exchanger system of the present invention.

[0013] In the figure: boiler 1, superheater 2, main steam pipeline 3, high-pressure steam accumulator 4, desuperheating and pressure-reducing device 5, high-pressure heat user 6, steam turbine 7, generator 8, condenser 9, low-pressure steam accumulator 10, low-pressure heat user 11, condensate pump 12, condensate tank 13, low-pressure heater 14, deaerator 15, feed water pump 16, high-pressure heater 17, economizer 18, feed water tank 19, feed water pump 20, feed water accumulator 21, feed water pump 22. Specific Embodiments

[0014] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0015] As Figure 1 shown.

[0016] A new type of heat storage heat exchanger system includes a boiler 1, a superheater 2, a main steam pipeline 3, a high-pressure steam accumulator 4, a desuperheating and pressure-reducing device 5, a high-pressure heat user 6, a steam turbine 7, a generator 8, a condenser 9, a low-pressure steam accumulator 10, a low-pressure heat user 11, a condensate pump 12, a condensate tank 13, a low-pressure heater 14, a deaerator 15, a feed water pump 16, a high-pressure heater 17, an economizer 18, a feed water tank 19, a feed water pump 20, a feed water accumulator 21, and a feed water pump 22. The outlet of the boiler 1 is connected to the superheater 2, and the steam enters the main steam pipeline 3. Most of the steam does work in the steam turbine 7 for power generation; another part stores heat through a variable-pressure high-pressure steam accumulator 4, and still another part goes to the high-pressure heat user 6 through the desuperheating and pressure-reducing device 5. The steam that has done work in the steam turbine passes through the condenser 9, and then successively passes through the condensate pump 12, the condensate tank 13, the low-pressure heater 14, the deaerator 15, the feed water pump 16, the high-pressure heater 17, and the economizer 18 and enters the boiler 1. Part of the steam entering the steam turbine 7 is sent to the low-pressure heat user 11, and another part heats the feed water through a constant-pressure feed water accumulator 21.

[0017] The inlet end of the high-pressure steam accumulator 4 is connected to the main steam pipeline 3, and the outlet end is located after the desuperheating and pressure-reducing valve 5 and before the high-pressure heat user. Electric control valves are arranged at the inlet and outlet of the high-pressure steam accumulator 4. The inlet valve is located between the main steam pipeline 3 and the inlet of the high-pressure steam accumulator, and the outlet valve is located before the outlet of the high-pressure steam accumulator to the high-pressure heat user, so as to control the steam balance among the high-pressure accumulator, the power generation amount, and the heat user. During normal operation, the inlet end valve of the high-pressure steam accumulator 4 is opened and the outlet end valve is closed for heat storage. When the demand load of the high-pressure user exceeds the heat supply in the system, the inlet end valve of the high-pressure steam accumulator 3 is closed and the outlet end valve is opened for supplementary heat supply. The inlet end of the low-pressure steam accumulator 10 is connected to the extraction pipeline, and the outlet end is connected to the low-pressure heat user 11. Electric control valves are arranged at the inlet and outlet of the low-pressure steam accumulator 10. The inlet valve is located between the extraction pipeline and the inlet of the low-pressure steam accumulator, and the outlet valve is located before the low-pressure heat user. During normal operation, the inlet end valve of the low-pressure steam accumulator 10 is opened and the outlet end valve is closed for heat storage. When the demand load of the low-pressure user exceeds the heat supply in the system, the inlet end valve of the low-pressure steam accumulator 10 is closed and the outlet end valve is opened for supplementary heat supply, so as to balance the steam consumption of different users. For the feed water accumulator 21, the make-up water is provided by the feed water tank 19 and enters the feed water accumulator 21 through the feed water pump 20 and the economizer 18. The extraction steam from the steam turbine 7 enters the feed water accumulator 21 to heat the feed water, and the heated feed water enters the boiler 1 through the feed water pump 22; one way is connected to the low-pressure heat user 11, and the return water finally reaches the boiler 1.

[0018] The present invention can be applied to the occasions with large day-night load fluctuations. By means of the high-pressure steam accumulator and the low-pressure steam accumulator, steam of different grades is stored. In the occasions with large differences in user load demands, the load fluctuation of the boiler is reduced, so that the boiler can always maintain a high efficiency operation. The application of the automatic regulating valve reduces the frequent actions caused by the fluctuations, which is of great significance for saving energy and realizing energy conservation and carbon reduction of the system.

[0019] The parts not involved in the present invention are the same as the prior art or can be realized by the prior art.

Claims

1. A new type of heat storage heat exchanger system, characterized by: It includes a boiler (1), a superheater (2), a main steam pipe (3), a high-pressure steam accumulator (4), a temperature and pressure reducing device (5), a high-pressure heat user (6), a steam turbine (7), a generator (8), a condenser (9), a low-pressure steam accumulator (10), a low-pressure heat user (11), a condensate pump (12), a condensate tank (13), a low-pressure heater (14), a deaerator (15), a first feedwater pump (16), a high-pressure heater (17), an economizer (18), a feedwater tank (19), a second feedwater pump (20), Feedwater heat accumulator (21), third feedwater pump (22); the outlet of the boiler (1) is connected to the superheater (2), steam enters the main steam pipe (3), a part of the steam is sent to the steam turbine (7) to do work, driving the generator (8) to generate electricity; another part enters the high-pressure steam heat accumulator (4) for heat storage, and another part is sent to the high-pressure heat user (6) through the temperature reducing and pressure reducing device (5); the steam that has done work in the steam turbine (7) enters the condenser (9), and then passes through the condensate pump (1) together with the steam used by the high-pressure heat user (6). 2), the condensate tank (13), the low-pressure heater (14), the deaerator (15), the first feed water pump (16), the high-pressure heater (17), and the economizer (18) enter the boiler (1), and the steam entering the turbine (7) is first sent to the low-pressure steam accumulator (10) and then to the low-pressure heat user (11) after exhaust, and the other part is passed through the constant-pressure feed water accumulator (21) to heat the feed water; the inlet end of the high-pressure steam accumulator (4) is connected to the main steam pipe (3), and the outlet end is located after the temperature reducer (5), the high-pressure heat accumulator (21) and the high-pressure heat accumulator (3) are connected to the main steam pipe (3), and the outlet end is located after the temperature reducer (5), the high-pressure heat accumulator (21) and the high-pressure heat accumulator (21) are connected to the main steam pipe (3), ... The position before the user (6); the inlet end of the low-pressure steam accumulator (10) is connected to the exhaust pipe, and the outlet end is connected to the low-pressure heat user (11); the feed water accumulator (21) is supplied with water by the feed water tank (19), and enters the feed water accumulator (21) via the second feed water pump (20) and the economizer (18); the exhaust air from the steam turbine (7) enters the feed water accumulator (21) to heat the feed water, and the heated feed water enters the boiler (1) by the third feed water pump (22); and is connected to the low-pressure heat user (11).

2. The novel heat storage heat exchanger system according to claim 1, characterized in that: The inlet and outlet of the high-pressure steam accumulator (4) are electrically controlled valves. The inlet valve is located between the main steam pipeline (3) and the inlet of the high-pressure steam accumulator, and the outlet valve is located before the outlet of the high-pressure steam accumulator to the high-pressure heat user, so as to control the steam balance between the high-pressure heat accumulator, power generation, and heat users. The inlet and outlet of the low-pressure steam accumulator (10) are electrically controlled valves. The inlet valve is located between the exhaust pipeline and the inlet of the low-pressure steam accumulator, and the outlet valve is located before the low-pressure heat user.

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