Efficient turbine power generation system

Abstract

The efficient steam turbine power generation system comprises a boiler, a steam turbine, a power generator, a condenser, a second pump, a third pump, a low-pressure heater, a deaerator and a high-pressure heater, the boiler provides steam for the steam turbine, the steam turbine drives the power generator to rotate, and low-pressure steam exhausted by the steam turbine enters the condenser; the condenser is sequentially connected with a low-pressure heater, a deaerator, a third pump and a high-pressure heater through a second pump, the high-pressure heater is connected with a boiler, the condenser is replaced by a heat pump, the heat pump comprises a compressor, a condenser, an evaporator, an expansion valve, a water tank and a first pump, and refrigerant circulates in a loop composed of the evaporator, the compressor, the condenser and the expansion valve. Low-pressure steam discharged by the turbine is connected with an inlet of the heat exchange side of the evaporator, an outlet of the heat exchange side of the evaporator is connected with an inlet of the water tank, an outlet of the water tank is connected with an inlet of the heat exchange side of the condenser through the first pump, and an outlet of the heat exchange side of the condenser is connected with the second pump.

Description

Technical Field

[0001] The invention relates to a steam turbine power generation system, in particular to a high-efficiency steam turbine power generation system. Background Art

[0002] During the power generation process of thermal power condensing steam turbine generator sets, the exhaust steam of the turbine must be re-condensed through circulating water, condenser, cooling water tower or air cooler, air cooling tower to form condensate. After the pressure is increased by the condensate pump, it is heated by the low-pressure heater, deaerator and high-pressure heater of the steam turbine and then supplied to the boiler, which is then heated to form superheated steam and enters the steam turbine for operation.

[0003] During the condensation process of turbine exhaust steam, a large amount of heat in the low-temperature and low-pressure exhaust steam of the turbine (generally accounting for about 45% of the heat utilized by the entire generator set) is discharged into the atmosphere after heat exchange through the cooling water tower (or air cooler, air cooling tower). This huge amount of heat is wasted and has a certain impact on the environment. Summary of the invention

[0004] The invention of this application aims to reduce the exhaust loss of a steam turbine and provide a high-efficiency steam turbine power generation system.

[0005] In order to achieve the invention purpose of this application, this application adopts the following technical solutions:

[0006] The invention discloses a high-efficiency steam turbine power generation system, which comprises: a boiler, a steam turbine, a generator, a condenser, a second pump, a third pump, a low-pressure heater, a deaerator and a high-pressure heater. The boiler provides steam for the steam turbine, the steam turbine drives the generator to rotate, the low-pressure steam discharged from the steam turbine enters the condenser, the condenser is connected to the low-pressure heater, the deaerator, the third pump and the high-pressure heater in sequence through the second pump, and the high-pressure heater is connected to the boiler, wherein: a heat pump is used to replace the condenser, the heat pump comprises: a compressor, a condenser, an evaporator, an expansion valve, a water tank and a first pump, the refrigerant circulates in a loop composed of the evaporator, the compressor, the condenser and the expansion valve, the low-pressure steam discharged from the steam turbine is connected to the inlet of the heat exchange side of the evaporator, the outlet of the heat exchange side of the evaporator is connected to the inlet of the water tank, the outlet of the water tank is connected to the inlet of the heat exchange side of the condenser through the first pump, and the outlet of the heat exchange side of the condenser is connected to the second pump.

[0007] The invention discloses a high-efficiency steam turbine power generation system, wherein: a vacuum pump is also installed on the evaporator, and the vacuum pump discharges the non-condensable gas in the evaporator.

[0008] The present invention provides a high-efficiency steam turbine power generation system, wherein: the high-efficiency steam turbine power generation system also includes: a refrigeration exchange device, which is installed on the connecting pipe between the outlet of the heat exchange side of the evaporator and the water tank through a valve, the refrigeration exchange device includes: a cold user and a refrigeration exchanger, the outlet of the heat exchange side of the evaporator is connected to the inlet of the cold water side of the refrigeration exchanger through a valve, the outlet of the cold water side of the refrigeration exchanger is connected to the inlet of the water tank through a valve, and the hot water side of the refrigeration exchanger and the cold user form a circulation loop.

[0009] The present invention provides a high-efficiency steam turbine power generation system, wherein: the steam turbine includes: a high-pressure cylinder, a high-pressure cylinder shaft, a coupling, an intermediate-pressure cylinder, an intermediate-pressure cylinder shaft, a steam guide pipe, a low-pressure cylinder and a low-pressure cylinder shaft, the high-pressure cylinder shaft is installed at the center of the high-pressure cylinder, the intermediate-pressure cylinder shaft is installed at the center of the intermediate-pressure cylinder, the low-pressure cylinder shaft is installed at the center of the low-pressure cylinder, the high-pressure cylinder shaft and the intermediate-pressure cylinder shaft are connected together through a coupling, the intermediate-pressure cylinder shaft and the low-pressure cylinder shaft are connected together through a coupling, the low-pressure cylinder shaft and the generator shaft are connected together through a coupling, the generator shaft is installed on the generator, the boiler provides steam for the high-pressure cylinder and the intermediate-pressure cylinder, the exhaust outlet of the intermediate-pressure cylinder is connected to the steam inlet of the low-pressure cylinder through the steam guide pipe, and the exhaust outlet of the low-pressure cylinder is connected to the inlet on the heat exchange side of the evaporator.

[0010] The invention discloses a high-efficiency steam turbine power generation system, wherein the refrigerant is carbon dioxide, R32, R34, R404A, R410A, R407C or R717.

[0011] The present invention provides a high-efficiency steam turbine power generation system, wherein: the boiler comprises: a steam drum, a superheater, a reheater and an economizer, the inlet of the superheater is connected to the outlet of the steam drum, the outlet of the superheater is connected to the steam inlet of the high-pressure cylinder, the outlet of the economizer is connected to the inlet of the steam drum, the inlet of the economizer is connected to the high-pressure heater, the exhaust outlet of the high-pressure cylinder is connected to the inlet of the reheater, and the outlet of the reheater is connected to the steam inlet of the medium-pressure cylinder.

[0012] The present invention is a high-efficiency steam turbine power generation system that utilizes heat pump equipment to extract heat from steam turbine exhaust for utilization. Compared with the existing steam turbine power generation system, it has the following advantages:

[0013] 1. The high-efficiency steam turbine power generation system of the present invention recycles 100% of the exhaust (exhaust steam) heat of the condensing steam turbine. Taking a 300,000-kilowatt wet cooling unit as an example, under the conditions of 75% load, 570 tons of exhaust per hour, 0.005 MPa of pressure, and 32 degrees of temperature, the latent heat of vaporization enthalpy of each kilogram of exhaust is about 2422.KJ / kg. The latent heat of vaporization of 570 tons of exhaust is equivalent to 47.19 tons of standard coal. That is to say, by fully recovering the exhaust steam vaporization latent heat of the steam turbine under this condition through this device, the condensate of the steam turbine is heated, and 47.19 tons of standard coal can be saved per hour. This part of coal carbon accounts for 52% of the coal consumption of the unit at full load power generation (calculated at 300 grams / kilowatt-hour). The amount of coal saved is huge. At the same time, due to the saving of coal, the corresponding unit exhaust volume is also greatly reduced, the corresponding fan consumption and the operating capacity of environmental protection equipment are also greatly reduced, and the environmental protection problems caused by the exhaust of the corresponding thermal power units are also greatly alleviated, which has a great role in promoting the country's carbon emission reduction work; for the wet cooling unit, since there is no need to use water tower cooling to cool the exhaust of the steam turbine, the cooling water consumption of about 600 tons per hour is eliminated, and there is no need to build a cooling water tower (air cooler, air cooling tower) and corresponding supporting measures when building a new condensing unit. This can greatly reduce the cost of the condensing steam turbine.

[0014] 2. The high-efficiency steam turbine power generation system of the present invention can eliminate the cooling water tower (or air cooler, air cooling tower) in the steam turbine auxiliary equipment and the corresponding design, equipment purchase, project construction land occupation, etc., thus reducing the huge engineering construction costs;

[0015] 3. The high-efficiency steam turbine power generation system of the present invention can significantly increase the condensate temperature and steam turbine vacuum of the operating unit, reduce the steam extraction volume of the steam turbine heat recovery extraction system, and improve the efficiency of the steam turbine generator set. It can reduce the huge coal consumption and the corresponding carbon dioxide emissions, and can soon fulfill the country's commitment to the world to reduce carbon dioxide emissions.

[0016] 4. The input of cooling water towers (air coolers, air cooling towers) can be reduced for the units in operation, which can greatly reduce the evaporation of cooling water towers (taking the water tower of a 300,000-kilowatt unit per hour as an example, the escaped and scattered water can reach 600 tons), reduce the impact of the heat dissipation of the air-cooled unit on the ambient temperature, and the power consumption of the corresponding auxiliary equipment, save a huge amount of water resources, and significantly reduce the operating costs of the generator set.

[0017] 5. By using the high-efficiency steam turbine power generation system of the present invention, heat can be extracted from the exhaust gas of the steam turbine. Without major modifications to the steam turbine body, the city can be heated in winter and cooled in summer by adding heat exchangers, refrigerators and the existing urban heating network. The urban heating area can be greatly increased without increasing the steam turbine extraction volume. Power generation companies can obtain better heating and cooling benefits.

[0018] 6. Although the high-efficiency steam turbine power generation system of the present invention merely replaces the condenser in the existing steam turbine power generation system with a heat pump, it effectively integrates the heat pump into the steam turbine power generation system, and the above-mentioned effects brought about by it are unexpected. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the connection relationship of the high-efficiency steam turbine power generation system of the present invention;

[0020] Figure 2 A schematic diagram showing the connection relationship of an existing steam turbine power generation system.

[0021] exist Figure 1 and Figure 2 In the figure, reference numeral 1 is a boiler; reference numeral 2 is a steam turbine; reference numeral 3 is a generator; reference numeral 4 is a heat pump; reference numeral 5 is a second pump; reference numeral 6 is a refrigeration exchange device; reference numeral 7 is a third pump; reference numeral 8 is a low-pressure heater; reference numeral 9 is a deaerator; reference numeral 10 is a high-pressure heater; reference numeral 11 is a steam drum; reference numeral 12 is a superheater; reference numeral 13 is a reheater; reference numeral 14 is an economizer; reference numeral 21 is a high-pressure cylinder; reference numeral 22 is a high-pressure cylinder shaft; reference numeral 23 is a coupling shaft The device is as follows: number 24 is a medium-pressure cylinder; number 25 is a medium-pressure cylinder shaft; number 26 is a steam guide pipe; number 27 is a low-pressure cylinder; number 28 is a low-pressure cylinder shaft; number 31 is a generator shaft; number 41 is a compressor; number 42 is a condenser; number 43 is an evaporator; number 44 is an expansion valve; number 46 is a water tank; number 47 is a first pump; number 48 is a valve; number 49 is a vacuum pump; number 61 is a cold user; number 62 is a refrigeration exchanger. DETAILED DESCRIPTION

[0022] like Figure 2 As shown, the existing steam turbine power generation system includes: a boiler 1, a steam turbine 2, a generator 3, a condenser, a second pump 5, a third pump 7, a low-pressure heater 8, a deaerator 9 and a high-pressure heater 10. The boiler 1 provides steam for the steam turbine 2, the steam turbine 2 drives the generator 3 to rotate, and the low-pressure steam discharged from the steam turbine 2 enters the condenser. The condenser is connected to the low-pressure heater 8, the deaerator 9, the third pump 7 and the high-pressure heater 10 in sequence through the second pump 5, and the high-pressure heater 10 is connected to the boiler 1.

[0023] like Figure 1As shown, the high-efficiency steam turbine power generation system of the present invention replaces the condenser with a heat pump 4, and the heat pump 4 includes: a compressor 41, a condenser 42, an evaporator 43, an expansion valve 44, a water tank 46, a first pump 47 and a vacuum pump 49. The refrigerant circulates in a loop composed of the evaporator 43, the compressor 41, the condenser 42 and the expansion valve 44. The low-pressure steam discharged from the steam turbine 2 is connected to the inlet of the heat exchange side of the evaporator 43, the outlet of the heat exchange side of the evaporator 43 is connected to the inlet of the water tank 46, the outlet of the water tank 46 is connected to the inlet of the heat exchange side of the condenser 42 through the first pump 47, and the outlet of the heat exchange side of the condenser 42 is connected to the second pump 5. A vacuum pump 49 is also installed on the evaporator 43, and the vacuum pump 49 discharges the non-condensable gas in the evaporator 43.

[0024] The high-efficiency steam turbine power generation system of the present invention also includes: a refrigeration exchange device 6, which is installed on the connecting pipe between the outlet of the heat exchange side of the evaporator 43 and the water tank 46 through a valve 48. The refrigeration exchange device includes: a cold user 61 and a refrigeration exchanger 62. The outlet of the heat exchange side of the evaporator 43 is connected to the inlet of the cold water side of the refrigeration exchanger 62 through a valve 48, and the outlet of the cold water side of the refrigeration exchanger 62 is connected to the inlet of the water tank 46 through a valve 48. The hot water side of the refrigeration exchanger 62 and the cold user 61 form a circulation loop. The refrigerant is carbon dioxide, R32, R34, R404A, R410A, R407C or R717.

[0025] like Figure 1 As shown, the steam turbine 2 includes: a high-pressure cylinder 21, a high-pressure cylinder shaft 22, a coupling 23, an intermediate-pressure cylinder 24, an intermediate-pressure cylinder shaft 25, a steam guide pipe 26, a low-pressure cylinder 27 and a low-pressure cylinder shaft 28. The high-pressure cylinder shaft 22 is installed at the center of the high-pressure cylinder 21, the intermediate-pressure cylinder shaft 25 is installed at the center of the intermediate-pressure cylinder 24, and the low-pressure cylinder shaft 28 is installed at the center of the low-pressure cylinder 27. The high-pressure cylinder shaft 22 and the intermediate-pressure cylinder shaft 25 are connected together through the coupling 23, the intermediate-pressure cylinder shaft 25 and the low-pressure cylinder shaft 28 are connected together through the coupling 23, the low-pressure cylinder shaft 28 and the generator shaft 31 are connected together through the coupling 23, and the generator shaft 31 is installed on the generator 3. The boiler 1 provides steam for the high-pressure cylinder 21 and the intermediate-pressure cylinder 24. The exhaust outlet of the intermediate-pressure cylinder 24 is connected to the steam inlet of the low-pressure cylinder 27 through the steam guide pipe 26, and the exhaust outlet of the low-pressure cylinder 27 is connected to the inlet of the heat exchange side of the evaporator 43.

[0026] like Figure 1 As shown, the boiler 1 includes: a steam drum 11, a superheater 12, a reheater 13 and an economizer 14, the inlet of the superheater 12 is connected to the outlet of the steam drum 11, the outlet of the superheater 12 is connected to the steam inlet of the high-pressure cylinder 21, the outlet of the economizer 14 is connected to the inlet of the steam drum 11, the inlet of the economizer 14 is connected to the high-pressure heater 10, the exhaust outlet of the high-pressure cylinder 21 is connected to the inlet of the reheater 13, and the outlet of the reheater 13 is connected to the steam inlet of the intermediate-pressure cylinder 24.

[0027] The steam generated by the boiler 1 is sent to the steam turbine 2 to drive the generator 3 to rotate. The low-pressure gas discharged from the steam turbine 2 enters the heat exchange side of the evaporator 43 of the heat pump 4, is cooled into water and sent to the water tank 46. The cooling water is sent to the heat exchange side of the condenser 42 through the first pump 47 and is heated. After that, it is sent to the low-pressure heater 8, the deaerator 9 and the high-pressure heater 10 in sequence through the second pump 5, and then enters the boiler to complete a water cycle of the high-efficiency steam turbine power generation system of the present invention. The refrigerant circulates in a loop composed of the evaporator 43, the compressor 41, the condenser 42 and the expansion valve 44. The cooling water coming out of the heat exchange side of the evaporator 43 can also provide a cold source for the refrigeration exchange device.

[0028] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. The present invention may be modified in any form without violating the spirit of the present invention.

Claims

1. A high-efficiency steam turbine power generation system, comprising: A boiler (1), a steam turbine (2), a generator (3), a condenser, a second pump (5), a third pump (7), a low-pressure heater (8), a deaerator (9) and a high-pressure heater (10), wherein the boiler (1) provides steam for the steam turbine (2), the steam turbine (2) drives the generator (3) to rotate, the low-pressure steam discharged from the steam turbine (2) enters the condenser, the condenser is connected to the low-pressure heater (8), the deaerator (9), the third pump (7) and the high-pressure heater (10) in sequence through the second pump (5), and the high-pressure heater (10) is connected to the boiler (1), characterized in that: the condenser is replaced by a heat pump (4), and the heat pump (4) includes The invention comprises a compressor (41), a condenser (42), an evaporator (43), an expansion valve (44), a water tank (46) and a first pump (47). The refrigerant circulates in a loop composed of the evaporator (43), the compressor (41), the condenser (42) and the expansion valve (44). The low-pressure steam discharged from the steam turbine (2) is connected to the inlet of the heat exchange side of the evaporator (43). The outlet of the heat exchange side of the evaporator (43) is connected to the inlet of the water tank (46). The outlet of the water tank (46) is connected to the inlet of the heat exchange side of the condenser (42) through the first pump (47). The outlet of the heat exchange side of the condenser (42) is connected to the second pump (5).

2. The high-efficiency steam turbine power generation system according to claim 1, characterized in that: The evaporator (43) is also provided with a vacuum pump (49) for discharging the non-condensable gas in the evaporator.

3. The high-efficiency steam turbine power generation system according to claim 2, characterized in that: The high-efficiency steam turbine power generation system further comprises: a refrigeration exchange device (6), which is installed on the connecting pipe between the outlet of the heat exchange side of the evaporator (43) and the water tank (46) through a valve (48), and the refrigeration exchange device comprises: a cold user (61) and a refrigeration exchanger (62), the outlet of the heat exchange side of the evaporator (43) is connected to the inlet of the cold water side of the refrigeration exchanger (62) through a valve (48), the outlet of the cold water side of the refrigeration exchanger (62) is connected to the inlet of the water tank (46) through a valve (48), and the hot water side of the refrigeration exchanger (62) and the cold user (61) form a circulation loop.

4. The high-efficiency steam turbine power generation system according to claim 3, characterized in that: The steam turbine (2) comprises: a high-pressure cylinder (21), a high-pressure cylinder shaft (22), a coupling (23), an intermediate-pressure cylinder (24), an intermediate-pressure cylinder shaft (25), a steam guide pipe (26), a low-pressure cylinder (27) and a low-pressure cylinder shaft (28); the high-pressure cylinder shaft (22) is mounted at the center of the high-pressure cylinder (21); the intermediate-pressure cylinder shaft (25) is mounted at the center of the intermediate-pressure cylinder (24); the low-pressure cylinder shaft (28) is mounted at the center of the low-pressure cylinder (27); the high-pressure cylinder shaft (22) and the intermediate-pressure cylinder shaft (25) are connected together via the coupling (23) The intermediate pressure cylinder shaft (25) and the low pressure cylinder shaft (28) are connected together through a coupling (23), the low pressure cylinder shaft (28) and the generator shaft (31) are connected together through a coupling (23), the generator shaft (31) is installed on the generator (3), the boiler (1) provides steam for the high pressure cylinder (21) and the intermediate pressure cylinder (24), the exhaust steam outlet of the intermediate pressure cylinder (24) is connected to the steam inlet of the low pressure cylinder (27) through a steam guide pipe (26), and the exhaust steam outlet of the low pressure cylinder (27) is connected to the inlet of the heat exchange side of the evaporator (43).

5. The high-efficiency steam turbine power generation system according to claim 4, characterized in that: The refrigerant is carbon dioxide, R32, R34, R404A, R410A, R407C or R717.

6. The high-efficiency steam turbine power generation system according to claim 5, characterized in that: The boiler (1) comprises: a steam drum (11), a superheater (12), a reheater (13) and an economizer (14); the inlet of the superheater (12) is connected to the outlet of the steam drum (11); the outlet of the superheater (12) is connected to the steam inlet of a high-pressure cylinder (21); the outlet of the economizer (14) is connected to the inlet of the steam drum (11); the inlet of the economizer (14) is connected to the high-pressure heater (10); the exhaust outlet of the high-pressure cylinder (21) is connected to the inlet of the reheater (13); and the outlet of the reheater (13) is connected to the steam inlet of the medium-pressure cylinder (24).

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