High-back-pressure dead steam waste heat recycling system of thermal power generating unit

Abstract

The utility model relates to a high-back-pressure dead steam waste heat recycling system of a thermal power generating unit, and relates to the field of dead steam waste heat utilization of thermal power generating units. The system comprises a heat supply network circulating water return pipeline, a heat supply network circulating water inlet pipeline, an air cooling circulating water pipeline, a plurality of high-back-pressure condensers located on a thermal power generating unit and connected to the air cooling circulating water pipeline, a low-pressure cylinder providing dead steam for the high-back-pressure condensers, and a condensate water pipeline connected to the high-back-pressure condensers. The water inlet ends of the high-back-pressure condensers are connected to a heat supply network circulating water return pipeline, the water inlet ends of the high-back-pressure condensers are connected to a heat supply network circulating water inlet pipeline, and control valves are arranged at the positions, close to the water inlet ends of the high-back-pressure condensers, of the heat supply network circulating water return pipeline and the air cooling circulating water pipeline. Effective utilization of the dead steam of the generator set can be achieved, the comprehensive energy utilization efficiency of a power plant is improved, the heat supply income is increased, meanwhile, all equipment is modified based on original equipment of the generator set, and resources are effectively saved.

Description

Technical Field

[0001] The present application relates to the field of exhaust steam waste heat utilization of thermal power generation units, and in particular to a high back pressure exhaust steam waste heat recovery and reuse system of thermal power generation units. Background Art

[0002] Energy conservation and emission reduction is an important issue for the sustainable development of my country's social economy. As a major energy consumer, energy conservation in thermal power plants has always been the focus of industrial energy conservation. With the continuous rise in fossil fuel prices, energy conservation and emission reduction is also an important means for power plants to save operating costs and improve economic benefits.

[0003] The cold end loss of a thermal power plant is the largest energy loss in the thermal system of the power plant. A large amount of waste heat from the high back pressure condenser of the steam turbine is discharged into the atmosphere through different cooling equipment. Under winter operating conditions of the power plant, the heat loss of the exhaust steam condensation of the steam turbine can account for 50-60% of the total calorific value of the fuel (the thermal power plant is also above 30%). The heat loss of the exhaust steam condensation of the steam turbine is waste heat emission for thermal power plants, but it constitutes a huge energy waste for building heating that requires low-grade thermal energy.

[0004] In the heating season, the heating load of the urban heating network is relatively large. If the waste heat from the condensation of the steam turbine can be recovered for heating of urban residents, it is equivalent to expanding the heating capacity of the heat source, improving the comprehensive energy utilization efficiency of the power plant, and increasing the heating income without increasing the capacity of the power plant, increasing the emission of atmospheric pollutants, and keeping the coal consumption and power generation unchanged. At the same time, since the evaporation and dissipation loss of the cooling system is reduced, the water replenishment of the circulating cooling water system of the power plant can also be reduced, saving water resources. Utility Model Content

[0005] In order to achieve the above-mentioned invention objectives, the present application provides a high back pressure exhaust steam waste heat recovery and reuse system for a thermal power unit.

[0006] The present application provides a thermal power unit high back pressure exhaust steam waste heat recovery and reuse system, which adopts the following technical solution:

[0007] A high back-pressure exhaust steam waste heat recovery and reuse system for a thermal power unit comprises a heat network circulating water return pipeline, a heat network circulating water inlet pipeline connected to a heat network circulating water station, an air-cooled circulating water pipeline located in the thermal power unit, a plurality of parallel high back-pressure condensers, a low-pressure cylinder located in the thermal power unit and providing exhaust steam for the high back-pressure condenser, and a condensate pipeline connected to the high back-pressure condenser, wherein the high back-pressure condenser is located in the thermal power unit and connected to the air-cooled circulating water pipeline, the water inlet end of the high back-pressure condenser is connected to the heat network circulating water return pipeline, the water inlet end of the high back-pressure condenser is connected to the heat network circulating water inlet pipeline, and the heat network circulating water return pipeline and the air-cooled circulating water pipeline are both provided with control valves near the water inlet end of each high back-pressure condenser.

[0008] Optionally, the heat network circulating water inlet pipeline and the air-cooling circulating water pipeline are also provided with control valves near the water outlet end of each high back pressure condenser.

[0009] Optionally, the heat network circulating water inlet pipeline is connected to a hot compressor condenser, the hot compressor condenser is connected to a condensate pipeline, the steam inlet of the hot compressor condenser is connected to a hot compressor, the hot compressor is connected to the exhaust steam outlet of the low-pressure cylinder, and the hot compressor is connected to a steam extraction pipeline.

[0010] Optionally, the hot water circulating water inlet pipeline is connected to a low-peak pipeline connected in parallel with the hot compressor condenser, and the low-peak pipeline and the water inlet of the hot compressor condenser are both provided with regulating valves.

[0011] Optionally, the condensate water pipeline is provided with a cooler.

[0012] Optionally, the waste heat recovery condenser is connected to a vacuum pipeline.

[0013] Optionally, the heat network circulating water return pipeline is connected to a decontamination device.

[0014] In summary, the present application includes at least one of the following beneficial technical effects:

[0015] 1. By connecting several high back pressure condensers in parallel between the heat network circulating water pipeline and the air cooling circulating water pipeline, the exhaust steam can be used to heat the heat network circulating water in the heating season, and the air cooling circulating water can be used to condense the exhaust steam in the non-heating season, so as to achieve effective utilization of the exhaust steam of the generator set, improve the comprehensive energy utilization efficiency of the power plant, increase the heating revenue, and at the same time, all the equipment is transformed based on the original equipment of the generator set, which effectively saves resources;

[0016] 2. By installing a heat compressor and a heat compressor condenser, the circulating water in the heat network can be further heated, and the temperature of the circulating water in the heat network can be adjusted through the low-peak pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a system schematic diagram of Example 1 of the present application;

[0018] Figure 2 It is a system schematic diagram of Example 2 of the present application.

[0019] Explanation of the reference numerals in the accompanying drawings: 1. Low-pressure cylinder; 2. High back-pressure condenser; 3. Heat network circulating water return pipeline; 31. Control valve; 4. Heat network circulating water inlet pipeline; 5. Condensate pipeline; 6. Decontaminant; 7. Air-cooled circulating water pipeline; 8. Hot press; 9. Hot press condenser; 10. Steam extraction pipeline; 11. Low-peak pipeline; 12. Regulating valve. DETAILED DESCRIPTION

[0020] The following is combined with Figure 1-2 This application is described in further detail.

[0021] The embodiment of the present application discloses a high back pressure exhaust steam waste heat recovery and reuse system for a thermal power unit.

[0022] Embodiment 1:

[0023] Reference Figure 1 A high back pressure exhaust steam waste heat recovery and reuse system for a thermal power unit is provided in an existing thermal power unit of a thermal power plant, and includes an air-cooled circulating water pipeline 7 located in the thermal power unit, a plurality of low-pressure cylinders 1, and high back pressure condensers 2 corresponding to the low-pressure cylinders 1. The low-pressure cylinders 1 provide exhaust steam for the corresponding high back pressure condensers 2. The plurality of high back pressure condensers 2 are connected to the air-cooled circulating water pipeline 7 to condense the exhaust steam. In this embodiment, two high back pressure condensers 2 are provided.

[0024] In order to utilize the waste heat of the exhaust steam of the low-pressure cylinder 1 of the thermal power unit in heating the heating network circulating water of the urban heating network, a high back-pressure waste heat recovery and reuse system for the exhaust steam of the thermal power unit also includes a heating network circulating water return pipeline 3 located in the urban heating network and a heating network circulating water inlet pipeline 4 connected to the heating network circulating water station. The inlet end of each high back-pressure condenser 2 is connected to the heating network circulating water return pipeline 3, and the outlet end of each high back-pressure condenser 2 is connected to the heating network circulating water inlet pipeline 4, so that the latent heat generated during the condensation of the exhaust steam in the low-pressure cylinder 1 of the thermal power unit is exchanged with the heating network circulating water, the heating network circulating water is heated, and the waste heat of the exhaust steam of the thermal power unit is recovered on the basis of the equipment of the original thermal power unit.

[0025] Control valves 31 are provided on the heat network circulating water return pipeline 3 near the water inlet end of each high back pressure condenser 2, on the air cooling circulating water pipeline 7 near the water inlet end of each high back pressure condenser 2, on the heat network circulating water inlet pipeline 4 near the water outlet end of each high back pressure condenser 2, and on the air cooling circulating water pipeline 7 near the water outlet end of each high back pressure condenser 2.

[0026] In the heating season, the control valves 31 of the heat network circulating water return pipe 3 close to the water inlet end of each high back pressure condenser 2 and the heat network circulating water inlet pipe 4 close to the water outlet end of each high back pressure condenser 2 are opened, and the control valves 31 of the air cooling circulating water pipe 7 close to the water inlet end of each high back pressure condenser 2 and the air cooling circulating water pipe 7 close to the water outlet end of each high back pressure condenser 2 are closed at the same time, so that the exhaust steam enters the high back pressure condenser to heat the heat network circulating water, so as to provide the heating supply of the urban heating network; in the non-heating season , close the control valve 31 of the heat network circulating water return pipe 3 near the water inlet end of each high back pressure condenser 2 and the heat network circulating water inlet pipe 4 near the water outlet end of each high back pressure condenser 2, and at the same time open the control valve 31 of the air-cooling circulating water pipe 7 near the water inlet end of each high back pressure condenser 2 and the air-cooling circulating water pipe 7 near the water outlet end of each high back pressure condenser 2, so that the air-cooling circulating water condenses the exhaust steam, so that the equipment can be used in both the heating season and the non-heating season, effectively saving resources.

[0027] Among them, each high back pressure condenser 2 is connected to a condensate pipeline 5 for discharging condensate after exhaust steam condensation. Since the high back pressure condenser 2 operates at a high back pressure, the condensate temperature in the condensate pipeline 5 is relatively high, and a cooler (not shown in the figure) is provided on the condensate pipeline 5 to reduce the condensate temperature. Each high back pressure condenser 2 is connected to a vacuum pipeline (not shown in the figure). In addition, in order to prevent impurities in the heat network circulating water from entering the high back pressure condenser 2, a decontaminator 6 is connected to the heat network circulating water return pipeline 3.

[0028] Embodiment 2:

[0029] Reference Figure 2 In this embodiment, based on the embodiment 1, the heat network circulating water inlet pipeline 4 is connected to a heat compressor condenser 9 for further heating the heat network circulating water. The heat compressor condenser 9 is connected to the condensate pipeline 5 for discharging condensed water. The steam inlet of the heat compressor condenser 9 is connected to a heat compressor 8, which is connected to the exhaust steam outlet of the low-pressure cylinder 1, and the heat compressor 8 is connected to a steam extraction pipeline 10. The exhaust steam of the low-pressure cylinder 1 and the steam in the steam extraction pipeline 10 provide a power source for the heat compressor 8.

[0030] Furthermore, in order to be able to adjust the temperature of the heat network circulating water, the heat compressor condenser 9 is connected in parallel with a low-peak pipeline 11, both ends of the low-peak pipeline 11 are connected to the heat network circulating water inlet pipeline 4, and the low-peak pipeline 11 and the water inlet of the heat compressor condenser 9 are both provided with regulating valves 12. By adjusting the opening of the two regulating valves 12 at the low-peak pipeline 11 and the water inlet of the heat compressor condenser 9, the temperature of the heat network circulating water can be controlled.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the description of the present invention, unless otherwise specified, the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0033] Finally, it should be explained that the above technical solution is only one implementation method of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the application methods and principles disclosed in the present invention, and it is not limited to the method described in the above specific implementation method of the present invention. Therefore, the method described above is only preferred and does not have a restrictive meaning.

Claims

1. A high back pressure exhaust steam waste heat recovery and reuse system for a thermal power unit, characterized in that: The invention comprises a heat network circulating water return pipeline (3), a heat network circulating water inlet pipeline (4) connected to a heat network circulating water station, an air-cooled circulating water pipeline (7) located in a thermal power unit, a plurality of parallel high back-pressure condensers (2), a low-pressure cylinder (1) located in the thermal power unit and providing exhaust steam for the high back-pressure condenser (2), and a condensate pipeline connected to the high back-pressure condenser (2), wherein the high back-pressure condenser (2) is located in the thermal power unit and connected to the air-cooled circulating water pipeline (7), the water inlet end of each high back-pressure condenser (2) is connected to the heat network circulating water return pipeline (3), the water inlet end of each high back-pressure condenser (2) is connected to the heat network circulating water inlet pipeline (4), and the heat network circulating water return pipeline (3) and the air-cooled circulating water pipeline (7) are both provided with a control valve (31) near the water inlet end of each high back-pressure condenser (2).

2. A high back pressure exhaust steam waste heat recovery and reuse system for a thermal power unit according to claim 1, characterized in that: The heat network circulating water inlet pipeline (4) and the air-cooling circulating water pipeline (7) are also provided with a control valve (31) near the water outlet end of each high back-pressure condenser (2).

3. A high back pressure exhaust steam waste heat recovery and reuse system for a thermal power unit according to claim 1, characterized in that: The heat network circulating water inlet pipeline (4) is connected to a hot compressor condenser (9), the hot compressor condenser (9) is connected to a condensate water pipeline (5), the steam inlet of the hot compressor condenser (9) is connected to a hot compressor (8), the hot compressor (8) is connected to the exhaust steam outlet of the low-pressure cylinder (1), and the hot compressor (8) is connected to a steam extraction pipeline (10).

4. A high back pressure exhaust steam waste heat recovery and reuse system for a thermal power unit according to claim 3, characterized in that: The hot water circulation water inlet pipeline is connected to a low-peak pipeline (11) connected in parallel with the heat compressor condenser (9), and the low-peak pipeline (11) and the water inlet of the heat compressor condenser (9) are both provided with a regulating valve (12).

5. A high back pressure exhaust steam waste heat recovery and reuse system for a thermal power unit according to claim 3, characterized in that: The condensate water pipeline (5) is provided with a cooler.

6. A high back pressure exhaust steam waste heat recovery and reuse system for a thermal power unit according to claim 1, characterized in that: The waste heat recovery condenser is connected with a vacuum pipeline.

7. The high back pressure exhaust steam waste heat recovery and reuse system of a thermal power unit according to claim 1, characterized in that: The heat network circulating water return pipeline (3) is connected to a dirt remover (6).

Images