Combined waste heat power generation system with back pressure steam turbine connected in series with condensing steam turbine

Abstract

The invention relates to a combined waste heat power generation system with a back pressure steam turbine connected in series with a condensing steam turbine. The problem that low-pressure dead steam exhausted by a single steam turbine power generation system is still rich in higher latent heat energy and cannot be fully utilized is solved. Comprising high-temperature flue gas (1), a back pressure steam turbine (2), a back pressure generator (3), a condensing steam turbine (4), a condensing generator (5), a condensing condenser and hot well (6), a condensing power generation cooling circulation water tower (7), a cooling circulation water pool (8), a cooling circulation water pump (9), a boiler water feeding pump (10), a deaerator (11), a coal economizer (12), a flue gas waste heat boiler (13), a steam pocket (14) and a flue gas superheater (15). According to the system, sensible heat energy of water vapor is more fully recycled, latent heat energy of dead steam condensation is further recycled, the sensible heat energy of the steam is efficiently utilized, steam condensate water is recycled, and multiple configuration combinations of grid-connected or isolated-grid operation of the two waste heat power generation systems are flexibly created.

Description

Technical Field

[0001] This invention patent belongs to the field of steam waste heat power generation, specifically relating to a combined waste heat power generation system of a back-pressure steam turbine and a condensing steam turbine. Background Technology

[0002] Waste heat power generation using steam is an important method in the field of waste heat recovery. Generally, pyrometallurgical enterprises, chemical plants, or power plants use a single back-pressure steam turbine or condensing steam turbine to drive a generator in order to efficiently recover and utilize heat energy, thereby realizing the conversion of heat energy into mechanical energy, and then into electrical energy. The advantages are a short process, simple equipment, and high safety technology. The disadvantage is that the low-pressure exhaust steam discharged from a single back-pressure steam turbine power generation system still contains a high amount of latent heat energy. Therefore, a condensing steam turbine can be connected in series to drive a generator, forming a combined waste heat power generation system and device. Compared with a single steam turbine generator, which can be operated in parallel or in isolation, two steam turbine generators can more flexibly realize various grid combinations between the generation end and the load end. Summary of the Invention

[0003] This invention utilizes a combined waste heat power generation system and device consisting of a back-pressure steam turbine connected in series with a condensing steam turbine. This system further improves the efficiency of utilizing steam sensible heat energy, recovering waste steam latent heat energy, and recovering steam condensate. It also flexibly creates various configuration combinations for grid-connected or islanded operation of the two steam turbine power generation systems in series mode.

[0004] This invention is achieved through the following technical solutions: A combined waste heat power generation system consisting of a back-pressure steam turbine and a condensing steam turbine in series includes high-temperature flue gas (1), a back-pressure steam turbine (2), a back-pressure generator (3), a condensing steam turbine (4), a condensing generator (5), a condensing condenser and a hot water well (6), a condensing power generation cooling circulating water tower (7), a cooling circulating water pool (8), a cooling circulating water pump (9), a boiler feed water pump (10), a deaerator (11), an economizer (12), a flue gas waste heat boiler (13), a steam drum (14), and a flue gas superheater (15). The high-temperature flue gas (1) passes sequentially through the flue gas superheater (15) and the flue gas waste heat boiler (16). The hot boiler (13) and economizer (12) recover waste heat through cooling. The outlets of the condensing condenser and hot water well (6) are connected to the inlet of the boiler feed pump (10) through pipelines. The outlet of the boiler feed pump (10) is connected to the water-side inlet of the deaerator (11) through pipelines. The outlet of the deaerator (11) is connected to the feed water inlet of the economizer (12) through pipelines. The feed water outlet of the economizer (12) is connected to the feed water inlet of the flue gas waste heat boiler (13) through pipelines. The water outlet of the flue gas waste heat boiler (13) is connected to the water-side inlet of the steam drum (14) through pipelines. The saturated steam outlet of the steam drum (14) is connected to the steam outlet of the flue gas superheater (15) through pipelines. The side inlet of the flue gas superheater (15) is connected to the back-pressure turbine (2) through a pipeline. The back-pressure turbine (2) drives the back-pressure generator (3) to generate electricity through the rotor coupling. The exhaust steam outlet of the back-pressure turbine (2) is connected to the condensing turbine (4) through a pipeline. The steam-side inlet of the condensing turbine (4) drives the condensing generator (5) to generate electricity through the rotor coupling. The exhaust steam outlet of the condensing turbine (4) is directly connected to the condensing condenser and the hot water well (6). The condensate outlet of the condensing condenser and the hot water well (6) is connected to the inlet of the boiler feedwater pump (10) through a pipeline, forming a closed loop. A series combined waste heat recovery power generation system and device; (8) the outlet of the cooling circulating water pool is connected to (9) the inlet of the cooling circulating water pump and the outlet of the cooling circulating water pump (9) are connected to (6) the condensing condenser and hot water well (6) the cooling water inlet, and the outlet of the condensing condenser and hot water well (6) the cooling water outlet is connected to the condensing power generation cooling circulating water tower (7) the inlet of the water tower, and the lower part of the condensing power generation cooling circulating water tower (7) is directly connected to the cooling circulating water pool (8), and then the cooling circulating water pump (9) forms a closed loop to form a condensing power generation cooling circulating water and condenser negative pressure generation system and a water vapor condensation recovery device.

[0005] This invention relates to a combined waste heat power generation system and device that uses a back-pressure steam turbine connected in series with a condensing steam turbine. Compared with a single back-pressure steam turbine generator, it not only recovers the sensible heat energy of water vapor more fully, but also recovers the latent heat energy of exhaust steam condensation, making efficient use of steam sensible heat energy. It also recovers steam condensate and flexibly creates a variety of configuration combinations for grid-connected or isolated operation of the two waste heat power generation systems. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the present invention. Detailed Implementation

[0007] like Figure 1 As shown, the present invention is a combined waste heat power generation system of back pressure steam turbine and condensing steam turbine, comprising five main parts: high temperature flue gas (1), back pressure steam turbine power generation system (2-3), condensing waste heat power generation system (4-6), condensing power generation cooling circulating water system (7-9), and water vapor waste heat recovery system (10-15).

[0008] Specifically, the present invention includes high-temperature flue gas (1), a back-pressure steam turbine (2), a back-pressure generator (3), a condensing steam turbine (4), a condensing generator (5), a condensing condenser and a hot water well (6), a condensing power generation cooling circulating water tower (7), a cooling circulating water pool (8), a cooling circulating water pump (9), a boiler feed water pump (10), a deaerator (11), an economizer (12), a flue gas waste heat boiler (13), a steam drum (14), and a flue gas superheater (15). Its characteristic is that the high-temperature flue gas (1) sequentially passes through the flue gas superheater (15), the flue gas waste heat boiler (13), and the economizer (15). 12) After cooling and recovering waste heat, the outlets of the condensing condenser and hot water well (6) are connected to the inlet of the boiler feed pump (10) via pipelines. The outlet of the boiler feed pump (10) is connected to the water-side inlet of the deaerator (11) via pipelines. The outlet of the deaerator (11) is connected to the feed water inlet of the economizer (12) via pipelines. The feed water outlet of the economizer (12) is connected to the feed water inlet of the flue gas waste heat boiler (13) via pipelines. The water outlet of the flue gas waste heat boiler (13) is connected to the water-side inlet of the steam drum (14) via pipelines. The saturated steam outlet of the steam drum (14) is connected to the steam-side inlet of the flue gas superheater (15) via pipelines. The superheated steam outlet of the turbine (15) is connected to the feed steam inlet of the back-pressure turbine (2) through a pipeline. The back-pressure turbine (2) drives the back-pressure generator (3) to generate electricity through the rotor coupling. The exhaust steam outlet of the back-pressure turbine (2) is connected to the steam inlet of the condensing turbine (4) through a pipeline. The condensing turbine (4) drives the condensing generator (5) to generate electricity through the rotor coupling. The exhaust steam outlet of the condensing turbine (4) is directly connected to the condensing condenser and the hot water well (6). The condensate outlet of the condensing condenser and the hot water well (6) is connected to the inlet of the boiler feed water pump (10) through a pipeline, forming two sets of series groups in a closed loop. Combined waste heat recovery power generation system and device; (8) The outlet of the cooling circulating water pool is connected to (9) the inlet of the cooling circulating water pump and the outlet of the cooling circulating water pump (9) are connected to (6) the condensing condenser and hot water well (6) the cooling water inlet, and the outlet of the condensing condenser and hot water well (6) the cooling water outlet is connected to the condensing power generation cooling circulating water tower (7) the inlet of the water tower, and the lower part of the condensing power generation cooling circulating water tower (7) is directly connected to the cooling circulating water pool (8), and then the cooling circulating water pump (9) forms a closed loop to form a condensing power generation cooling circulating water and condenser negative pressure generation system and a water vapor condensation recovery device.

[0009] Taking a sulfuric acid plant attached to a hydrometallurgical mining enterprise as an example: The project is located in an African country where power outages are frequent and the power grid supply is extremely unstable. The project uses high-temperature flue gas from sulfur combustion, which is cooled by a sulfur incinerator, boiler, converter, three-stage superheater, and economizer before being sent to a primary absorption tower for treatment. It can produce approximately 32 tons of superheated steam at 440℃ and 3.6MPa per hour. The superheated steam is then piped to a back-pressure turbine to drive a generator, which can generate approximately 2.5MW / h of electricity per hour. This back-pressure generator unit operates in isolation, driving the sulfur... The sulfuric acid plant operates its own equipment without the generator carrying excess load, enabling it to operate continuously throughout the year without being affected by external power grid outages. The exhaust steam from the back-pressure turbine is superheated steam at approximately 270°C and 0.52 MPa, which is piped to a condensing turbine to drive a generator that generates approximately 2.2 MW / h of electricity. This condensing generator unit drives some key equipment in the beneficiation plant. The generator unit operates in an isolated grid, not connected to the municipal power grid, ensuring that key equipment in the area can operate continuously without being affected by external power grid outages.

[0010] The present invention has the following beneficial effects: 1. By connecting a condensing steam turbine in series with the exhaust steam from a back-pressure steam turbine, not only can the pressure energy of steam be used to generate electricity through the back-pressure steam turbine, but the condensation potential energy of steam can also be used to generate electricity, which greatly improves the heat energy recovery and utilization rate compared with a single steam turbine generator set.

[0011] 2. Condensate is pumped through the boiler feedwater pump, passing through the deaerator, boiler, steam drum, superheater, back-pressure steam turbine, and then into the condensing steam turbine, condenser, and hot water well in a closed loop. Condensate can be repeatedly pumped through the boiler feedwater pump in the entire combined waste heat power generation system. Compared with a single back-pressure steam turbine, this greatly improves the utilization rate of steam and condensate and saves boiler feedwater costs. 3. The back-pressure steam turbine generator set and the condensing steam turbine generator set are independent of each other and do not interfere with each other. They can be connected to the grid independently, connected to each other, or operated in isolation. This flexibly creates a variety of configuration combinations for the two waste heat power generation systems to be connected to the grid or operated in isolation. It can adapt to various grid power supply scenarios in different countries and regions, and is not affected by external power supply, ensuring the safe and stable operation of key and important equipment and facilities in the production system.

Claims

1. A combined waste heat power generation system of back-pressure steam turbine and condensing steam turbine, characterized in that: Including high temperature Flue gas (1), back-pressure steam turbine (2), back-pressure generator (3), condensing steam turbine (4), condensing generator (5), condensing condenser and hot water well (6), condensing power generation cooling circulating water tower (7), cooling circulating water pool (8), cooling circulating water pump (9), boiler feed water pump (10), deaerator (11), economizer (12), flue gas waste heat boiler (13), steam drum (14), flue gas superheater (15). The high-temperature flue gas (1) passes sequentially through the flue gas superheater (15), flue gas waste heat boiler (13), and economizer (12) to recover waste heat through cooling. The outlets of the gas condenser and hot water well (6) are connected to the inlet of the boiler feed pump (10) via pipes. The outlet of the boiler feed pump (10) is connected to the water-side inlet of the deaerator (11) via pipes. The outlet of the deaerator (11) is connected to the feed inlet of the economizer (12) via pipes. The feed outlet of the economizer (12) is connected to the feed inlet of the flue gas waste heat boiler (13) via pipes. The water outlet of the flue gas waste heat boiler (13) is connected to the water-side inlet of the steam drum (14) via pipes. The saturated steam outlet of the steam drum (14) is connected to the steam-side inlet of the flue gas superheater (15) via pipes. The superheated steam outlet of the flue gas superheater (15) is connected to the steam-side inlet of the flue gas superheater (15). The steam-side outlet is connected to the steam inlet of the back-pressure turbine (2) via a pipeline. The back-pressure turbine (2) drives the back-pressure generator (3) to generate electricity via a rotor coupling. The exhaust steam outlet of the back-pressure turbine (2) is connected to the steam-side inlet of the condensing turbine (4) via a pipeline. The condensing turbine (4) drives the condensing generator (5) to generate electricity via a rotor coupling. The exhaust steam outlet of the condensing turbine (4) is directly connected to the condensing condenser and the hot water well (6). The condensate outlet of the condensing condenser and the hot water well (6) is connected to the inlet of the boiler feedwater pump (10) via a pipeline, forming a closed loop of two sets of series combined waste heat. The system and device for recycling power generation; (8) the outlet of the cooling circulating water pool is connected to (9) the inlet of the cooling circulating water pump and the outlet of the cooling circulating water pump (9) are connected to (6) the condensing condenser and hot water well (6) the cooling water inlet, the condensing condenser and hot water well (6) the cooling water outlet is connected to the condensing power generation cooling circulating water tower (7) the inlet of the water tower, the lower part of the condensing power generation cooling circulating water tower (7) is directly connected to the cooling circulating water pool (8), and then the cooling circulating water pump (9) forms a closed loop to form a condensing power generation cooling circulating water and condenser negative pressure generation system and a water vapor condensation recovery device.

2. The combined waste heat power generation system of back-pressure steam turbine and condensing steam turbine in series according to claim 1, characterized in that: The condensing steam turbine (4) drives the condensing generator (5) to generate electricity through the rotor coupling.

3. A combined waste heat power generation system of back-pressure steam turbine and condensing steam turbine in series according to claim 1, characterized in that: The back-pressure turbine (2) drives the back-pressure generator (3) to generate electricity through the rotor coupling.

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