CN115234959A - Supercritical steam turbine heating system - Google Patents

Abstract

The invention relates to a supercritical steam turbine heating system, which comprises a boiler, a supercritical steam turbine unit, a main steam heating pipeline, a reheat steam heating pipeline and a main heating pipe, wherein the main steam heating pipeline is connected with the reheat steam heating pipeline; the supercritical steam turbine set comprises a high-pressure cylinder and an intermediate-pressure cylinder, wherein a steam inlet of the high-pressure cylinder is communicated with a main steam pipe, and a steam inlet of the intermediate-pressure cylinder is communicated with a main reheat steam pipe; the steam outlet end of a main steam outlet pipe of the boiler is respectively communicated with the steam inlet end of a main steam heat supply pipeline and the steam inlet end of a main steam main pipe through a main steam three-way joint, and the steam outlet of the high-pressure cylinder is communicated with the steam inlet of the boiler; the steam outlet end of a reheat steam outlet pipe of the boiler is respectively communicated with the steam inlet end of the reheat steam heat supply pipeline and the steam inlet end of the reheat steam main pipe through a reheat steam tee joint; the steam outlet end of the main steam heat supply pipeline and the steam outlet end of the reheat steam heat supply pipeline are communicated with the steam inlet end of the main heat supply pipeline through a heat supply three-way joint. The energy-saving device has the advantages of capability of meeting the requirements, simple structure and high energy efficiency.

Description

Supercritical steam turbine heating system

Technical Field

The invention relates to the technical field of heating systems, in particular to a heating system of a supercritical steam turbine.

Background

At present, with the continuous development of economy in China, a thermal power generation system is more and more perfect, the thermal power generation system is more flexible, the stabilization and peak shaving of a power grid are facilitated, deep peak shaving power generation needs to be continuously carried out according to the requirements of the power grid, meanwhile, the heat supply stability and quality requirements of thermal power users corresponding to thermal power enterprises are also continuously improved, and further, the industrial heat supply requirement of a supercritical steam turbine unit is higher and higher.

Because the heat user has higher requirements on the temperature and the pressure of the heating steam, the existing heating system adopting the supercritical steam turbine set mainly uses the first steam extraction of the supercritical steam turbine set to supply heat, and the steam parameters of the heating system cannot meet the requirements of the heat user. If the mixed heat supply of the extraction steam and the main steam is adopted, the original compact and complex supercritical steam turbine system becomes more complex due to the newly added extraction pipeline. And because of the demand of peak shaving power generation of the supercritical steam turbine set, the load factor of the set is generally not high, and parameters of heat supply steam are adjusted to parameters required by a heat user by adopting parameter adjustment of a middle connection valve (a middle pressure combined steam valve), so that the middle pressure adjusting valve is in a deep throttling state for a long time, the efficiency of a middle pressure cylinder of the supercritical steam turbine is reduced by more than 10%, and the running economy of the supercritical steam turbine is seriously influenced.

Therefore, a supercritical steam turbine heating system which meets the requirements, has a simple structure and is high in energy efficiency is urgently needed.

Disclosure of Invention

Technical problem to be solved

In view of the above disadvantages and shortcomings of the prior art, the present invention provides a heating system of a supercritical steam turbine, which solves the technical problems of unsatisfied demand, complicated structure and low energy efficiency.

(II) technical scheme

In order to achieve the purpose, the invention adopts the main technical scheme that:

the invention provides a supercritical steam turbine heat supply system which comprises a boiler for generating main steam and reheat steam, a supercritical steam turbine unit, a main steam heat supply pipeline capable of being switched on and off selectively, a reheat steam heat supply pipeline capable of being switched on and off selectively and a main heat supply pipe. The supercritical steam turbine set comprises a high-pressure cylinder and an intermediate-pressure cylinder, wherein a main steam pipe is communicated with a steam inlet of the high-pressure cylinder, and a main reheat steam pipe is communicated with a steam inlet of the intermediate-pressure cylinder. The steam outlet end of a main steam outlet pipe of the boiler is respectively communicated with the steam inlet end of a main steam heat supply pipeline and the steam inlet end of a main steam main pipe through a main steam three-way joint, and the steam outlet of the high-pressure cylinder is communicated with the steam inlet of the boiler. The steam outlet end of a reheat steam outlet pipe of the boiler is respectively communicated with the steam inlet end of the reheat steam heat supply pipeline and the steam inlet end of the reheat steam main pipe through a reheat steam tee joint. The steam outlet end of the main steam heat supply pipeline and the steam outlet end of the reheat steam heat supply pipeline are communicated with the steam inlet end of the main heat supply pipeline through a heat supply three-way joint. When in heat supply, a main steam heat supply pipeline is selected for heat supply or a reheat steam heat supply pipeline is selected for heat supply according to the load of the supercritical steam turbine unit; when the load of the supercritical steam turbine unit exceeds 80% of the rated power of the supercritical steam turbine unit, switching on the reheat steam heat supply pipeline and switching off the main steam heat supply pipeline, and adopting the reheat steam heat supply pipeline for heat supply; when the load of the supercritical steam turbine unit is lower than 70% of the rated power of the supercritical steam turbine unit, the main steam heat supply pipeline is conducted, the reheat steam heat supply pipeline is disconnected, and the main steam heat supply pipeline is adopted for supplying heat.

Optionally, the main steam heat supply pipeline comprises a main steam branch pipe, a main steam temperature and pressure reducer and a main steam heat supply pipe which are sequentially connected. The steam inlet end of the main steam branch pipe is communicated with a main steam three-way joint, and the steam outlet end of the main steam heat supply pipe is communicated with a heat supply three-way joint. A first gate valve and a bypass, and a second gate valve and a bypass are sequentially arranged on the main steam branch pipe; a first flowmeter and a first heat supply gate valve are sequentially arranged on the main steam heat supply pipe.

Optionally, the first gate valve and the bypass include a first gate valve and a first bypass communicating with the main steam branch pipe portion on two sides of the first gate valve, and two first bypass stop valves are arranged on the first bypass. The second gate valve and the bypass comprise a second gate valve and a second bypass communicated with main steam branch pipe parts on two sides of the second gate valve, and two second bypass stop valves are arranged on the second bypass. And the second bypass part between the two second bypass stop valves is also communicated with a main steam drain pipe, and a main steam drain valve is arranged on the main steam drain pipe.

Optionally, the reheating steam heat supply pipeline comprises a reheating steam branch pipe, a reheating steam temperature and pressure reducer and a reheating steam heat supply pipe which are sequentially connected. The steam inlet end of the reheating steam branch pipe is communicated with the reheating steam three-way joint, and the steam outlet end of the reheating steam heat supply pipe is communicated with the heat supply three-way joint. And a third gate valve and a bypass are arranged on the reheating steam branch pipe, and a second flowmeter and a second heat supply gate valve are sequentially arranged on the reheating steam heat supply pipe.

Optionally, the third gate valve and the bypass include a third gate valve and a third bypass communicating with the reheat steam branch pipe portions on two sides of the third gate valve, and two third bypass cut-off valves are arranged on the third bypass. And a third bypass part between the two third bypass stop valves is also communicated with a reheat steam drain pipe, and the reheat steam drain pipe is provided with a reheat steam drain valve.

Optionally, the boiler further comprises a water feeding pump and a desuperheating water pipeline, wherein a first water outlet of the water feeding pump is communicated with a water inlet of the boiler through a main water feeding pipeline. The temperature reduction water pipeline comprises a temperature reduction water pipe, a main steam temperature reduction water pipe and a reheat steam temperature reduction water pipe. The water inlet end of the temperature reduction water pipe is communicated with a second water outlet of the water feed pump, and the water outlet end of the temperature reduction water pipe is respectively communicated with the water inlet end of the main steam temperature reduction water pipe and the water inlet end of the reheat steam temperature reduction water pipe through a temperature reduction water three-way joint. The water outlet end of the main steam temperature-reducing water pipe is communicated with a main steam heat supply pipeline and used for reducing the temperature and the pressure of the main steam. The water outlet end of the reheat steam temperature reduction water pipe is communicated with the reheat steam heat supply pipeline and is used for reducing the temperature and the pressure of the reheat steam.

Optionally, a first temperature-reducing water assembly is arranged on the main steam temperature-reducing water pipe, and a second temperature-reducing water assembly is arranged on the reheat steam temperature-reducing water pipe. The first desuperheating water subassembly includes according to desuperheating water flow direction set gradually first desuperheating water electric check valve, first desuperheating water filter, first desuperheating water electric control valve and first desuperheating water check valve. The second desuperheating water component comprises a second desuperheating water electric stop valve, a second desuperheating water filter, a second desuperheating water electric regulating valve and a second desuperheating water check valve which are sequentially arranged according to the flow direction of desuperheating water.

Optionally, a main steam stop valve and a main steam regulating valve are sequentially arranged on the main steam pipe according to the main steam flow direction. The reheat steam main pipe is sequentially provided with a reheat steam stop valve and a reheat steam regulating valve according to the flow direction of the reheat steam.

Optionally, a first drain pipeline is connected to the main steam heat supply pipe, and the first drain pipeline includes a first drain pipe, and a first drain stop valve and a first drain valve which are arranged on the first drain pipe.

Optionally, a second drain pipeline is connected to the reheating steam heating pipe, and the second drain pipeline includes a second drain pipe, and a second drain stop valve and a second drain valve which are arranged on the second drain pipe.

(III) advantageous effects

The invention has the beneficial effects that:

according to the supercritical steam turbine heating system provided by the invention, the parameters of the main steam and the reheated steam are respectively adjusted through the main steam heating pipeline and the reheated steam heating pipeline, so that the parameters of the main steam and the parameters of the reheated steam both meet the requirements. And then the main steam heat supply pipeline and the reheat steam heat supply pipeline are communicated with a main heat supply pipe through a heat supply three-way joint. During the heat supply, according to the load of supercritical steam turbine unit, choose for use main steam heat supply pipeline heat supply or reheat steam heat supply pipeline heat supply, can eliminate the influence that intermediate pressure jar efficiency descends under the unit low-load, can guarantee the economic nature of heat supply under the unit high load again to improve the utilization efficiency of the energy, and two pipeline heat supplies can each other be reserve heat source, guarantee to provide lasting stable heat source. Compared with the prior art, the heat source device has the advantages of meeting the requirements, being simple in structure and high in energy efficiency, and being capable of providing a continuous and stable heat source.

Drawings

Fig. 1 is a schematic diagram of a connection structure of a heating system of a supercritical steam turbine according to an embodiment of the present invention;

FIG. 2 is a schematic view of a connection structure of a first gate valve and a bypass and a second gate valve and a bypass according to an embodiment of the present invention;

FIG. 3 is a schematic view of a connection structure of a third gate valve and a bypass according to an embodiment of the present invention;

FIG. 4 is a schematic view of a connection structure of a first desuperheating water assembly according to an embodiment of the present invention;

fig. 5 is a schematic view of a connection structure of a first drain line according to an embodiment of the present invention.

[ description of reference ]

100: a main steam outlet pipe; 101: a main steam tee joint; 102: a main steam branch pipe; 103: a main steam pipe; 104: a main steam stop valve; 105: a main steam regulating valve; 106: a first gate valve and a bypass; 107: a second gate valve and a bypass; 108: a main steam temperature and pressure reducer; 109 a first flow meter; 110: a first heat supply gate valve; 111: a main steam heat supply pipe; 112: a first drain line; 113: a first gate valve; 114: a first bypass cut-off valve; 115: a second gate valve; 116: a second bypass cut-off valve; 117: a main steam trap; 118: a first hydrophobic stop valve; 119: a first trap; 120: a heat supply bypass stop valve;

200: a reheat steam outlet pipe; 201 reheat steam tee; 202 reheat steam legs; 203: a reheat steam main pipe; 204: a reheat steam stop valve; 205: a reheat steam adjusting valve; 206: a reheat steam check valve; 207: a third gate valve and a bypass; 208: a reheat steam trap; 209: a reheat steam temperature and pressure reducer; 210: a second flow meter; 211: a second heat supply gate valve; 212: a reheat steam heating pipe; 213: a second drain line; 214: a third gate valve; 215: a third bypass cut-off valve;

300: a desuperheating water pipeline; 301: a temperature-reducing water three-way joint; 302: a first desuperheating water assembly; 303: a second desuperheating water assembly; 304: a first electric stop valve for reducing temperature water; 305: a first desuperheating water filter; 306: a first electric regulating valve for reducing temperature; 307: a first desuperheating water check valve;

400: a main heating pipe; 401: a safety valve: 402: a heat supply three-way joint;

500: a boiler; 501: a high pressure cylinder; 502: an intermediate pressure cylinder; 503: a low pressure cylinder; 504: a feed pump turbine; 505: a feed pump; 506: a condenser.

Detailed Description

In order to better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

As shown in fig. 1 to 5, the supercritical steam turbine heating system according to the embodiment of the present invention includes a multi-unit heating channel composed of a main steam heating pipeline and a reheat steam heating pipeline, and can supply heat by using the main steam heating pipeline or the reheat steam heating pipeline according to the load of the supercritical steam turbine unit, and two heat supply pipelines can be mutually backup heat sources, so as to improve the energy utilization efficiency and ensure to provide a continuous and stable heat source. The heating system specifically comprises a boiler 500 for generating main steam and reheat steam, a supercritical steam turbine set, a main steam heating pipeline capable of being switched on and off selectively, a reheat steam heating pipeline capable of being switched on and off selectively and a main heating pipe 400. The supercritical steam turbine set comprises a high-pressure cylinder 501 and a medium-pressure cylinder 502, wherein a steam inlet of the high-pressure cylinder 501 is connected with a main steam pipe 103, and a steam inlet of the medium-pressure cylinder 502 is connected with a main reheat steam pipe 203. The steam outlet end of the main steam outlet pipe 100 of the boiler 500 is respectively communicated with the steam inlet end of the main steam heat supply pipeline and the steam inlet end of the main steam main pipe 103 through a main steam three-way joint 101, and the steam outlet of the high-pressure cylinder 501 is communicated with the steam inlet of the boiler 500. The outlet end of the reheat steam outlet pipe 200 of the boiler 500 is respectively communicated with the steam inlet end of the reheat steam heat supply pipeline and the steam inlet end of the reheat steam main pipe 203 through a reheat steam three-way joint 201. The steam outlet end of the main steam heat supply pipeline and the steam outlet end of the reheat steam heat supply pipeline are communicated with the steam inlet end of the main heat supply pipeline 400 through a heat supply three-way joint 403, and a safety valve 401 is arranged on the main heat supply pipeline 400. When in heat supply, a main steam heat supply pipeline is selected for heat supply or a reheat steam heat supply pipeline is selected for heat supply according to the load of the supercritical steam turbine unit; when the load of the supercritical steam turbine unit exceeds 80% of the rated power of the supercritical steam turbine unit, switching on the reheat steam heat supply pipeline and switching off the main steam heat supply pipeline, and adopting the reheat steam heat supply pipeline for heat supply; when the load of the supercritical steam turbine unit is lower than 70% of the rated power of the supercritical steam turbine unit, the main steam heat supply pipeline is conducted, the reheat steam heat supply pipeline is disconnected, and the main steam heat supply pipeline is adopted for supplying heat. When the load of the supercritical steam turbine unit is 70-80% of the rated power, one of the two heat supply pipelines can be selected. The heat supply flow in the main heat supply pipe 400 is 40-100 t/h, the temperature is 400-500 ℃, and the pressure is 3.4-4.5 MPa.

Specifically, in this heating system, divide main steam and reheat steam into partly through main steam heat supply pipeline and reheat steam heat supply pipeline and be used for the heat supply, adjust main steam and reheat steam's parameter respectively through main steam heat supply pipeline and reheat steam heat supply pipeline, make the parameter of main steam and reheat steam's parameter all satisfy the demand. Then, the main steam heat supply pipeline and the reheat steam heat supply pipeline are communicated with the main heat supply pipeline 400 through a heat supply three-way joint 403. During the heat supply, according to the load of supercritical steam turbine unit, choose for use main steam heat supply pipeline heat supply or reheat steam heat supply pipeline heat supply, can eliminate the influence that intermediate pressure jar 502 inefficiency descends under the unit low-load, can guarantee the economic nature of heat supply under the unit high load again to improve the utilization efficiency of the energy, and two pipeline heat supplies can each other be reserve heat source, guarantee to provide lasting stable heat source. Compared with the prior art, the heat source device meets the requirements, is simple in structure and high in energy efficiency, and can also provide a continuous and stable heat source.

Further, as shown in fig. 1, the supercritical steam turbine heating system according to the embodiment of the present invention further includes a water supply pump 505 and a desuperheating water pipeline 300, wherein a first water outlet of the water supply pump 505 is communicated with a water inlet of the boiler 500 through a main water supply pipeline. The temperature-reduced water line 300 includes a temperature-reduced water pipe, a main steam temperature-reduced water pipe, and a reheat steam temperature-reduced water pipe. The water inlet end of the temperature-reducing water pipe is communicated with a second water outlet of the water feeding pump 505, and the water outlet end of the temperature-reducing water pipeline 300 is respectively communicated with the water inlet end of the main steam temperature-reducing water pipe and the water inlet end of the reheat steam temperature-reducing water pipe through a temperature-reducing water three-way joint 301. The water outlet end of the main steam temperature-reducing water pipe is communicated with a main steam heat supply pipeline and used for reducing the temperature and the pressure of the main steam. The water outlet end of the reheat steam temperature reduction water pipe is communicated with the reheat steam heat supply pipeline and is used for reducing the temperature and the pressure of the reheat steam.

Further, as shown in fig. 1 and 4, a first desuperheating water assembly 302 is disposed on the main steam desuperheating water pipe, and a second desuperheating water assembly 303 is disposed on the reheat steam desuperheating water pipe. The first desuperheating water assembly 302 comprises a first desuperheating water electric stop valve 304, a first desuperheating water filter 305, a first desuperheating water electric regulating valve 306 and a first desuperheating water check valve 307 which are arranged in sequence in the desuperheating water flow direction. The second desuperheating water component 303 includes a second desuperheating water electric stop valve, a second desuperheating water filter, a second desuperheating water electric regulating valve and a second desuperheating water check valve which are sequentially arranged in the desuperheating water flow direction. The quality and the flow of main steam desuperheating water (desuperheating water for main steam) and reheat steam desuperheating water (desuperheating water for reheat steam) are respectively controlled through the first desuperheating water component 302 and the second desuperheating water component 303, the service lives of a main steam heat supply pipeline and a reheat steam heat supply pipeline are prolonged, and the use efficiencies of the main steam desuperheating water and the reheat steam desuperheating water are improved. The circulation and the sealing of the main steam temperature-reducing water are controlled by a first temperature-reducing water electric stop valve (304). The hardness of the main steam desuperheating water is reduced by the first desuperheating water filter 305, and the generation of mineral deposits on the inner wall of the main steam pipe is avoided, thereby affecting the flow rate of the main steam and reducing the service life of the pipe. The flow of the main steam desuperheating water is controlled through the first desuperheating water electric regulating valve 306, and the service efficiency of the main steam desuperheating water is improved. The reverse flow of the main steam desuperheated water is prevented by the first desuperheated water check valve 307. Similarly, the circulation and the closure of the reheated steam desuperheating water are controlled by a second electric stop valve. Reduce the hardness of reheat steam desuperheating water through second desuperheating water filter, avoid producing the mineral substance on reheat steam pipe's the inner wall and deposit, influence reheat steam velocity of flow and reduce the pipeline life-span. The electric regulating valve of the second desuperheating water is used for controlling the flow of the reheated steam desuperheating water, so that the use efficiency of the reheated steam desuperheating water is improved. The reheated steam desuperheating water is prevented from flowing backwards through the second desuperheating water check valve.

Further, as shown in fig. 1, the main steam heat supply pipeline includes a main steam branch pipe 102, a main steam temperature and pressure reducer 108, and a main steam heat supply pipe 111, which are connected in sequence. The steam inlet end of the main steam branch pipe 102 is connected with the main steam three-way joint 101, and the steam outlet end of the main steam heat supply pipe 111 is connected with the heat supply three-way joint 403. The main steam branch pipe 102 is sequentially provided with a first gate valve and bypass 106 and a second gate valve and bypass 107, and the main steam heat supply pipe 111 is sequentially provided with a first flowmeter 109 and a first heat supply gate valve 110. Wherein, first heat supply gate valve 110 also is provided with heat supply bypass and heat supply bypass stop valve 120 on the heat supply bypass, is convenient for opening and closing of first heat supply gate valve 110. The water outlet end of the main steam temperature-reducing water pipe is communicated with the main steam temperature-reducing pressure reducer 108, and the main steam with high temperature and high pressure is subjected to temperature reduction and pressure increase through the main steam temperature-reducing pressure reducer 108, so that the parameter requirements of a heat user on the steam are met. The main steam flow in the main steam heating pipe 111 is measured by the first flowmeter 109, so that the main steam flow can be controlled as required.

Specifically, main steam heating pipe 111 passes through heat supply three way connection 403 and the switch-on of reheat steam heating pipe and main heating pipe 400, and when using reheat steam heating pipe heat supply, reheat steam can heat up main steam heating pipe 111, and main steam heating pipe 111 and the valve isotructure on the main steam heating pipe 111 can slowly heat up to being close to operating temperature, makes it be in hot standby state. Likewise, main steam branch 102 also needs to be on hot standby. First gate valve and bypass 106 and second gate valve and bypass 107 are used to flexibly and precisely control the entry of a small amount of main steam into main steam branch 102, to slowly raise temperature of main steam branch 102 to near operating temperature, and to maintain main steam branch 102 at near operating temperature. The steam pipeline is in a hot standby state before the steam is introduced, namely the steam pipeline is a heating pipe. Therefore, the steam pipeline is prevented from being damaged due to the fact that large thermal stress is generated on structures such as pipelines and valves when a large amount of high-temperature and high-pressure steam is suddenly introduced into the cold steam pipeline. And when steam enters the cold steam pipeline, condensed water can be generated on the inner wall of the steam pipeline, and then a strong water hammer phenomenon is caused, so that the pipeline falls down or is damaged.

Further, as shown in fig. 2, the first gate valve and bypass 106 includes a first gate valve 113 and a first bypass communicating with the main steam branch 102 on both sides of the first gate valve 113, and two first bypass cut-off valves 114 are provided on the first bypass. The second gate valve and bypass 107 includes a second gate valve 115 and a second bypass communicating with the main steam branch 102 on both sides of the second gate valve 115, and two second bypass cut-off valves 116 are provided on the second bypass. The second bypass portion between the two second bypass cut-off valves 116 is also connected to a main steam trap, which is provided with a main steam trap 117. Because in the high-pressure steam pipeline, there is very big pressure differential in the gate valve both sides of closing, easily the card dies and produces too big opening torque, sets up the bypass and the bypass stop valve on the bypass at the steam pipeline of gate valve both sides can open the bypass stop valve earlier before the gate valve is opened, makes the non-pressure pipeline section pressurize in order to reduce pressure differential, makes to open the gate valve resistance and reduces. Thereby, opening and closing of the first gate valve 113 and the second gate valve 115 are facilitated. The condensed water in the main steam branch pipe 102 is discharged in time through the main steam trap. Therefore, the condensed water in the pipeline is prevented from being accumulated and quickly brought up by main steam to form a water hammer, and the water hammer impacts the pipeline wall and the valve to cause pipeline damage or even personal injury. The main steam trap 117 has the greatest functions of blocking steam and draining water (blocking steam and discharging water), preventing main steam from leaking, and saving steam. The discharged condensed water can be drained or recycled according to the requirement.

Further, as shown in fig. 1, the reheat steam heat supply line includes a reheat steam branch pipe 202, a reheat steam temperature reducer 209, and a reheat steam heat supply pipe 212, which are sequentially connected. The steam inlet end of the branch reheat steam pipe 202 is connected with the three-way reheat steam joint 201, and the steam outlet end of the heat reheat steam heating pipe 212 is connected with the three-way heat supply joint 403. A third gate valve and a bypass 207 are provided in the reheat steam branch pipe 202, and a second flow meter 210 and a second heat supply gate valve 211 are sequentially provided in the reheat steam heat supply pipe 212. The water outlet end of the reheat steam temperature reduction water pipe is communicated with a reheat steam temperature reduction pressure reducer 209, and the reheat steam with relatively high temperature and high pressure is subjected to temperature reduction and pressurization through the reheat steam temperature reduction pressure reducer 209, so that the parameter requirements of a heat user on the steam are met. The reheat steam flow in the reheat steam heating pipe 212 is measured through the second flow meter 210, so that the reheat steam flow can be controlled as required. And the third gate valve and the bypass 207 are used for conveniently and flexibly controlling the reheat steam branch pipe 202 to warm the pipe. The reheat steam branch pipe 202 is also provided with a reheat steam check valve 206, which prevents backflow of reheat steam and influences the flow rate of reheat steam.

Further, as shown in fig. 3, the third gate valve and bypass 207 includes a third gate valve 214 and a third bypass communicating with portions of the reheat steam branch pipes 202 on both sides of the third gate valve 214, and two third bypass cut-off valves 215 are provided in the third bypass. A reheat steam trap is connected to the third bypass portion between the two third bypass cut-off valves 215, and a reheat steam trap 208 is provided in the reheat steam trap. Opening and closing of the third gate valve 214 is facilitated by the third bypass and third bypass cut-off valve 215. The condensed water in the reheat steam branch pipe 202 is discharged in time through the reheat steam drain pipe, so that the pipeline damage and even the personal injury are avoided. Leakage of reheat steam is prevented by the reheat steam trap 208 blocking steam and draining water.

Further, as shown in fig. 1, the main steam main pipe 103 is provided with a main steam stop valve 104 and a main steam adjusting valve 105 in order of the main steam flow direction, and the main reheat steam main pipe 203 is provided with a main reheat steam stop valve 204 and a main reheat steam adjusting valve 205 in order of the reheat steam flow direction. The main steam stop valve 104 is used to control the flow and closing of the main steam into the high pressure cylinder 501. The main steam control valve 105 is used to control the flow of main steam into the high pressure cylinder 501. Reheat steam stop valve 204 is used to control the flow and closing of reheat steam into intermediate pressure cylinder 502. Reheat steam control valve 205 is used to control the flow of reheat steam into intermediate pressure cylinder 502.

Further, as shown in fig. 1 and 5, a first drain line 112 is connected to the main steam heating pipe 111, and the first drain line 112 includes a first drain pipe, and a first drain stop valve 118 and a first drain valve 119 disposed on the first drain pipe. The first drain line 112 is used to discharge condensed water formed after the main steam is reduced in temperature and pressure. The opening and closing of first drain line 112 is controlled by a first stop valve. The first steam trap 119 blocks steam and discharges water to prevent the leakage of the heat supply steam in the main steam heat supply pipe 111.

Further, as shown in fig. 1, a second drain line 213 is connected to the reheat steam heating pipe 212, and the second drain line 213 includes a second drain pipe, and a second drain stop valve and a second drain valve disposed on the second drain pipe. The opening and closing of the second drain line 213 is controlled by a second shut-off valve. And the heat supply steam in the reheat steam heat supply pipe 212 is prevented from leaking through the steam stop and drainage of the second steam trap.

Further, as shown in fig. 1, the heating system further includes a condenser 506 and a feed pump turbine 504, and the turbine further includes a low pressure cylinder 503. A first steam outlet of the intermediate pressure cylinder 502 is communicated with a steam inlet of a low pressure cylinder 503, and a steam outlet of the low pressure cylinder 503 is communicated with a first steam inlet of a condenser 506. A second steam outlet of the intermediate pressure cylinder 502 is communicated with a steam inlet of the feed water pump turbine 504, and a steam outlet of the feed water pump turbine 504 is communicated with a second steam inlet of the condenser 506. The condenser 506 is used for condensing the exhaust steam discharged from the low-pressure cylinder 503 and the feed-water pump turbine 504 into water for the boiler 500 to reuse, thereby forming a circulation system. The feed pump turbine 504 is used to drive the feed pump 505 and meet the water supply requirements of the boiler 500 and the desuperheating water line 300.

Specifically, the steam turbine is a rotary power machine that converts the energy of steam into mechanical work, and is used as a prime mover for power generation. As shown in fig. 1, the boiler 500 introduces the produced high-temperature and high-pressure main steam into the high-pressure cylinder 501 to do work, the high-pressure cylinder 501 introduces the done main steam into the boiler 500 to reheat, the boiler 500 introduces the reheated steam into the intermediate pressure cylinder 502 to continue doing work, the intermediate pressure cylinder 502 introduces the done reheated steam into the low-pressure cylinder 503 to continue doing work, and finally the low-pressure cylinder 503 introduces the exhaust steam into the condenser 506 to improve the utilization rate of energy in such a manner of doing work step by step. The rotor of the steam turbine drives the rotor of the generator through the coupler so as to drive the generator to generate electricity.

Preferably, the main steam temperature-reducing pressure reducer 108 and the reheat steam temperature-reducing pressure reducer 209 are both split type temperature-reducing pressure reducers, the temperature reduction and the pressure reduction are separately performed, and the pressure reduction is performed by using a single pressure reducing valve. The split type temperature and pressure reducing device has high control precision, stable operation and sensitive adjustment, and can effectively eliminate the static difference influence.

The specific working conditions of the supercritical steam turbine heating system provided by the specific embodiment of the invention are that, firstly, the main steam stop valve 104 and the main steam regulating valve 105 are opened, the main steam main pipe 103 is conducted, the high-temperature and high-pressure main steam generated by the boiler 500 is introduced into the high-pressure cylinder 501 through the main steam main pipe 103 to do work, the high-pressure cylinder 501 introduces the finished main steam into the boiler 500 to reheat and generate reheat steam, the reheat steam stop valve 204 and the reheat steam regulating valve 205 are opened, the reheat steam main pipe 203 is conducted, and the reheat steam is introduced into the intermediate-pressure cylinder 502 through the reheat steam main pipe 203 to continue the subsequent work flow of the supercritical steam turbine. Then, a small amount of main steam is controlled to warm main steam branch 102 by first bypass cut-off valve 114 and second bypass cut-off valve 16, a small amount of reheat steam is controlled to warm reheat steam branch 202 by third bypass cut-off valve 215, and main steam branch 102 and reheat steam branch 202 are both kept in a hot standby state. And then the main steam heating pipe 111 is heated. After the heating pipe is completed, the first gate valve 113 and the second gate valve 115 are opened, the main steam branch pipe 102 is conducted, main steam is led into the main steam branch pipe 102 and enters the main steam temperature and pressure reducing device 108, the main steam drain valve 117 is opened, and the main steam drain pipe is conducted to drain water in time. Meanwhile, the temperature-reducing water in the Zhu Zhengqi temperature-reducing water pipe is controlled by the first temperature-reducing water electric regulating valve 306 to be led into the main steam temperature-reducing pressure reducer 108, the temperature of the main steam is reduced to 400-500 ℃ through the main steam temperature-reducing pressure reducer 108, the pressure is reduced to 3.5-4.5 MPa, the heat supply steam formed after temperature and pressure reduction is led into the main steam heat supply pipe 111, the first drainage stop valve 118 and the first drainage valve 119 are opened, the first drainage pipeline 112 is conducted to drain water in time, the heat supply steam flow is monitored through the first flowmeter 109, and timely adjustment is facilitated. The first heat supply gate valve 110 is opened to conduct the main steam heat supply pipe 111, so that the heat supply steam is introduced into the main heat supply pipe 400 to supply heat to the user. The reheat steam heating pipe 212 reaches a hot standby state by back warming the heating steam. In the process of using the main steam for heating, when the load of the supercritical steam turbine exceeds 80% of the rated power of the supercritical steam turbine, the third gate valve 214 is firstly opened, the reheat steam branch pipe 203 is conducted, the reheat steam is led into the reheat steam temperature and pressure reducer 209, the reheat steam trap 208 is opened, and the reheat steam trap is conducted to drain water in time. Meanwhile, the electric regulating valve of the second desuperheating water controls the desuperheating water in the reheated steam desuperheating water pipe to be led into the reheated steam desuperheating pressure reducer 209, the reheated steam desuperheating pressure reducer 209 is controlled to reduce the temperature of the reheated steam to 400-500 ℃, the pressure to 3.5-4.5 MPa, and the reheated steam is led into the main heat supply pipe 400. When the reheating steam is used for temperature and pressure reduction, the main steam flow in the main steam branch pipe 102 is controlled to be gradually reduced through the first bypass stop valve 114 and the second bypass stop valve 16, after the parameter of the reheating steam is subjected to temperature and pressure reduction to a required parameter, the main steam branch pipe 102 is closed through the first gate valve 113 and the second gate valve 115, the reheating steam is used for heat supply, and the main steam heat supply pipe 111 is maintained in a heat standby state under the action of the reheating steam. In the process of using the reheat steam to supply heat, when the load of the supercritical steam turbine set is lower than 70% of the rated power, similarly, the main steam is firstly introduced into the main steam temperature and pressure reducing device 108, the flow rate of the reheat steam in the reheat steam branch pipe 202 is gradually reduced while the main steam is subjected to temperature and pressure reduction, and the reheat steam branch pipe 202 is closed after the parameter of the main steam is subjected to temperature and pressure reduction to reach a required parameter. Thereby maintaining a stable heat source.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium; either as communication within the two elements or as an interactive relationship of the two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Although embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are illustrative and not restrictive, and that those skilled in the art may make changes, modifications, substitutions and alterations to the above embodiments without departing from the scope of the present invention.

Claims (10)

1. A supercritical steam turbine heating system is characterized by comprising a boiler (500) for generating main steam and reheated steam, a supercritical steam turbine unit, a main steam heating pipeline capable of being switched on and off selectively, a reheated steam heating pipeline capable of being switched on and off selectively and a main heating pipe (400);

the supercritical steam turbine set comprises a high-pressure cylinder (501) and a medium-pressure cylinder (502), wherein a main steam pipe (103) is communicated with a steam inlet of the high-pressure cylinder (501), and a main reheat steam pipe (203) is communicated with a steam inlet of the medium-pressure cylinder (502);

the steam outlet end of a main steam outlet pipe (100) of the boiler (500) is respectively communicated with the steam inlet end of a main steam heat supply pipeline and the steam inlet end of a main steam pipe (103) through a main steam three-way joint (101), and the steam outlet of a high-pressure cylinder (501) is communicated with the steam inlet of the boiler (500);

the steam outlet end of a reheat steam outlet pipe (200) of the boiler (500) is respectively communicated with the steam inlet end of a reheat steam heat supply pipeline and the steam inlet end of a reheat steam main pipe (203) through a reheat steam three-way joint (201);

the steam outlet end of the main steam heat supply pipeline and the steam outlet end of the reheat steam heat supply pipeline are communicated with the steam inlet end of the main heat supply pipeline (400) through a heat supply three-way joint (403);

when the load of the supercritical steam turbine unit exceeds 80% of the rated power of the supercritical steam turbine unit, switching on the reheat steam heat supply pipeline and switching off the main steam heat supply pipeline, and adopting the reheat steam heat supply pipeline for heat supply;

when the load of the supercritical steam turbine unit is lower than 70% of the rated power of the supercritical steam turbine unit, the main steam heat supply pipeline is conducted, the reheat steam heat supply pipeline is disconnected, and the main steam heat supply pipeline is adopted for supplying heat.

2. The supercritical turbine heating system according to claim 1,

the main steam heat supply pipeline comprises a main steam branch pipe (102), a main steam temperature and pressure reducer (108) and a main steam heat supply pipe (111) which are sequentially communicated;

the steam inlet end of the main steam branch pipe (102) is communicated with a main steam three-way joint (101), and the steam outlet end of the main steam heat supply pipe (111) is communicated with a heat supply three-way joint (403);

a first gate valve and a bypass (106) and a second gate valve and a bypass (107) are sequentially arranged on the main steam branch pipe (102);

the main steam heat supply pipe (111) is sequentially provided with a first flowmeter (109) and a first heat supply gate valve (110).

3. The supercritical turbine heating system according to claim 2,

the first gate valve and bypass (106) comprises a first gate valve (113) and a first bypass communicated with the main steam branch pipe (102) part at two sides of the first gate valve (113), and two first bypass stop valves (114) are arranged on the first bypass;

the second gate valve and bypass (107) comprises a second gate valve (115) and a second bypass communicated with the main steam branch pipe (102) part on two sides of the second gate valve (115), and two second bypass stop valves (116) are arranged on the second bypass;

the second bypass part between the two second bypass stop valves (116) is also communicated with a main steam drain pipe, and a main steam drain valve (117) is arranged on the main steam drain pipe.

4. The supercritical turbine heating system according to claim 1,

the reheat steam heat supply pipeline comprises a reheat steam branch pipe (202), a reheat steam temperature and pressure reducer (209) and a reheat steam heat supply pipe (212) which are sequentially communicated;

the steam inlet end of the reheating steam branch pipe (202) is communicated with a reheating steam three-way joint (201), and the steam outlet end of the reheating steam heat supply pipe (212) is communicated with a heat supply three-way joint (403);

a third gate valve and a bypass (207) are arranged on the reheating steam branch pipe (202); the reheating steam heating pipe (212) is sequentially provided with a second flowmeter (210) and a second heating gate valve (211).

5. The supercritical turbine heating system according to claim 4,

the third gate valve and bypass (207) comprises a third gate valve (214) and a third bypass communicated with the reheating steam branch pipe (202) part at two sides of the third gate valve (214), and two third bypass stop valves (215) are arranged on the third bypass;

and a reheat steam drain pipe is communicated with the third bypass part between the two third bypass stop valves (215), and a reheat steam drain valve (208) is arranged on the reheat steam drain pipe.

6. A supercritical turbine heating system as claimed in claim 1 wherein,

the boiler also comprises a water feeding pump (505) and a temperature reducing water pipeline (300), wherein a first water outlet of the water feeding pump (505) is communicated with a water inlet of the boiler (500) through a main water feeding pipeline;

the temperature-reducing water pipeline (300) comprises a temperature-reducing water pipe, a main steam temperature-reducing water pipe and a reheat steam temperature-reducing water pipe; the water inlet end of the temperature reduction water pipe is communicated with a second water outlet of the water feeding pump (505), and the water outlet end of the temperature reduction water pipeline (300) is respectively communicated with the water inlet end of the main steam temperature reduction water pipe and the water inlet end of the reheat steam temperature reduction water pipe through a temperature reduction water three-way joint (301);

the water outlet end of the main steam temperature-reducing water pipe is communicated with a main steam heat supply pipeline and is used for reducing the temperature and the pressure of the main steam; the water outlet end of the reheating steam temperature-reducing water pipe is communicated with a reheating steam heat supply pipeline and is used for reducing the temperature and the pressure of the reheating steam.

7. The supercritical turbine heating system according to claim 6,

a first temperature-reducing water component (302) is arranged on the main steam temperature-reducing water pipe, and a second temperature-reducing water component is arranged on the reheat steam temperature-reducing water pipe;

the first desuperheating water component (302) comprises a first desuperheating water electric stop valve (304), a first desuperheating water filter (305), a first desuperheating water electric regulating valve (306) and a first desuperheating water check valve (307) which are sequentially arranged according to the flow direction of desuperheating water;

the second desuperheating water component (303) comprises a second desuperheating water electric stop valve, a second desuperheating water filter, a second desuperheating water electric regulating valve and a second desuperheating water check valve which are sequentially arranged according to the flow direction of desuperheating water.

8. The supercritical turbine heating system according to claim 1,

a main steam stop valve (104) and a main steam regulating valve (105) are sequentially arranged on the main steam pipe (103) according to the main steam flow direction;

the main reheat steam pipe (203) is provided with a reheat steam stop valve (204) and a reheat steam adjusting valve (205) in sequence according to the flow direction of the reheat steam.

9. The supercritical turbine heating system according to claim 2,

a first drain pipeline (112) is communicated with the main steam heating pipe (111), and the first drain pipeline (112) comprises a first drain pipe, a first drain stop valve (118) and a first drain valve (119) which are arranged on the first drain pipe.

10. A supercritical turbine heating system as claimed in claim 4 wherein,

the reheating steam heating pipe (212) is connected with a second drain pipeline (213), and the second drain pipeline (213) comprises a second drain pipe, and a second drain stop valve and a second drain valve which are arranged on the second drain pipe.

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