A supercritical steam turbine heating system

Abstract

The present invention relates to a supercritical steam turbine heating system, which includes a boiler, a supercritical steam turbine unit, a main steam heating pipeline, a reheat steam heating pipeline and a main heating pipe; the supercritical steam turbine unit includes a high-pressure cylinder and an intermediate-pressure cylinder, the steam inlet of the high-pressure cylinder is connected to the main steam main pipe, and the steam inlet of the intermediate-pressure cylinder is connected to the reheat steam main pipe; the steam outlet end of the main steam outlet pipe of the boiler is connected to the steam inlet end of the main steam heating pipeline and the steam inlet end of the main steam main pipe respectively through a main steam tee joint, and the steam outlet of the high-pressure cylinder is connected to the steam inlet of the boiler; the steam outlet end of the reheat steam outlet pipe of the boiler is connected to the steam inlet end of the reheat steam heating pipeline and the steam inlet end of the reheat steam main pipe respectively through a reheat steam tee joint; the steam outlet end of the main steam heating pipeline and the steam outlet end of the reheat steam heating pipeline are connected to the steam inlet end of the main heating pipe through a heating tee joint. The beneficial effects of the system are that the system can meet the needs, has a simple structure and high energy efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of heating systems, and in particular to a supercritical steam turbine heating system. Background Art

[0002] At present, with the continuous development of my country's economy, thermal power generation systems are becoming more and more perfect. They are more flexible and convenient for the stability and peak regulation of the power grid. They need to continuously generate power according to the needs of the power grid. At the same time, the heat users corresponding to thermal power companies have continuously increased their demands for heat supply stability and quality, and thus the industrial heating requirements for supercritical steam turbine units are also getting higher and higher.

[0003] Because heat users have relatively high requirements for heating steam temperature and pressure, current heating systems using supercritical steam turbines primarily rely on primary extraction steam from the supercritical steam turbines for heating, and its steam parameters cannot meet the needs of heat users. If primary extraction steam and main steam are combined for heating, the already compact and complex supercritical steam turbine system will become even more complex due to the addition of extraction steam piping. Furthermore, due to the need for peak-shaving power generation for supercritical steam turbines, the load rate of the units is generally low. Using a central valve (intermediate pressure combined steam valve) to adjust the heating steam parameters to the parameters required by heat users would cause the intermediate pressure regulating valve to remain in a deep throttling state for a long time, resulting in a more than 10% decrease in the efficiency of the supercritical steam turbine's intermediate pressure cylinder, seriously affecting the economic efficiency of supercritical steam turbine operation.

[0004] Therefore, there is an urgent need for a supercritical steam turbine heating system that meets the needs, has a simple structure and high energy efficiency. Summary of the Invention

[0005] (1) Technical issues to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a supercritical steam turbine heating system, which solves the technical problems of being unable to meet demand, having a complex structure and having low energy efficiency.

[0007] (2) Technical solution

[0008] In order to achieve the above objectives, the main technical solutions adopted by the present invention include:

[0009] The present invention provides a supercritical steam turbine heating system, comprising a boiler for producing main steam and reheat steam, a supercritical steam turbine unit, a main steam heating pipeline that can be selectively switched on and off, a reheat steam heating pipeline that can be selectively switched on and off, and a main heating pipe. The supercritical steam turbine unit comprises a high-pressure cylinder and an intermediate-pressure cylinder, wherein the steam inlet of the high-pressure cylinder is connected to a main steam pipe, and the steam inlet of the intermediate-pressure cylinder is connected to a reheat steam pipe. The steam outlet of the main steam outlet pipe of the boiler is connected to the steam inlet of the main steam heating pipeline and the steam inlet of the main steam pipe respectively via a main steam tee joint, and the steam outlet of the high-pressure cylinder is connected to the steam inlet of the boiler. The steam outlet of the reheat steam outlet pipe of the boiler is connected to the steam inlet of the reheat steam heating pipeline and the steam inlet of the reheat steam pipe respectively via a reheat steam tee joint. The steam outlets of the main steam heating pipeline and the reheat steam heating pipeline are connected to the steam inlet of the main heating pipe via a heating tee joint. Among them, when supplying heat, the main steam heating pipeline or the reheat steam heating pipeline is selected for heating according to the load of the supercritical steam turbine unit; when the load of the supercritical steam turbine unit exceeds 80% of its rated power, the reheat steam heating pipeline is connected and the main steam heating pipeline is disconnected, and the reheat steam heating pipeline is used for heating; when the load of the supercritical steam turbine unit is lower than 70% of its rated power, the main steam heating pipeline is connected and the reheat steam heating pipeline is disconnected, and the main steam heating pipeline is used for heating.

[0010] Optionally, the main steam heating pipeline includes a main steam branch pipe, a main steam desuperheater and pressure reducer, and a main steam heating pipe, all connected in sequence. The steam inlet of the main steam branch pipe is connected to a main steam tee, and the steam outlet of the main steam heating pipe is connected to a heating tee. A first gate valve and a bypass, and a second gate valve and a bypass, are sequentially provided on the main steam branch pipe; and a first flowmeter and a first heating gate valve are sequentially provided on the main steam heating pipe.

[0011] Optionally, the first gate valve and bypass system includes a first gate valve and a first bypass connecting the main steam branch pipe sections on both sides of the first gate valve, with two first bypass stop valves installed on the first bypass system. The second gate valve and bypass system includes a second gate valve and a second bypass connecting the main steam branch pipe sections on both sides of the second gate valve, with two second bypass stop valves installed on the second bypass system. The second bypass section between the two second bypass stop valves is also connected to a main steam trap, which is equipped with a main steam trap.

[0012] Optionally, the reheated steam heating pipeline includes a reheated steam branch pipe, a reheated steam desuperheater and pressure reducer, and a reheated steam heating pipe, all connected in sequence. The steam inlet of the reheated steam branch pipe is connected to a reheated steam tee, and the steam outlet of the reheated steam heating pipe is connected to a heating tee. The reheated steam branch pipe is provided with a third gate valve and a bypass, and the reheated steam heating pipe is provided with a second flowmeter and a second heating gate valve in sequence.

[0013] Optionally, the third gate valve and bypass includes a third gate valve and a third bypass connecting the reheat steam branch pipe sections on both sides of the third gate valve. The third bypass section is provided with two third bypass stop valves. The third bypass section between the two third bypass stop valves is also connected to a reheat steam drain pipe, which is provided with a reheat steam drain valve.

[0014] Optionally, it also includes a feed water pump and a cooling water pipeline, and the first water outlet of the feed water pump is connected to the water inlet of the boiler through the main feed water pipeline. The cooling water pipeline includes a cooling water pipe, a main steam cooling water pipe, and a reheat steam cooling water pipe. The water inlet end of the cooling water pipe is connected to the second water outlet of the feed water pump, and the water outlet end of the cooling water pipe is connected to the water inlet end of the main steam cooling water pipe and the water inlet end of the reheat steam cooling water pipe respectively through a cooling water tee joint. The water outlet end of the main steam cooling water pipe is connected to the main steam heating pipeline for cooling and reducing the pressure of the main steam. The water outlet end of the reheat steam cooling water pipe is connected to the reheat steam heating pipeline for cooling and reducing the pressure of the reheat steam.

[0015] Optionally, a first attemperating water assembly is provided on the main steam attemperating water pipe, and a second warm water assembly is provided on the reheat steam attemperating water pipe. The first attemperating water assembly includes a first attemperating water electric stop valve, a first attemperating water filter, a first attemperating water electric regulating valve, and a first attemperating water check valve, arranged in sequence according to the attemperating water flow direction. The second attemperating water assembly includes a second attemperating water electric stop valve, a second attemperating water filter, a second attemperating water electric regulating valve, and a second attemperating water check valve, arranged in sequence according to the attemperating water flow direction.

[0016] Optionally, a main steam stop valve and a main steam regulating valve are sequentially provided on the main steam main pipe according to the main steam flow direction. A reheat steam stop valve and a reheat steam regulating valve are sequentially provided on the reheat steam main pipe according to the reheat steam flow direction.

[0017] Optionally, the main steam heating pipe is connected to a first drain pipeline, which includes a first drain pipe and a first drain stop valve and a first drain valve provided on the first drain pipe.

[0018] Optionally, the reheated steam heating pipe is connected to a second drain pipeline, which includes a second drain pipe and a second drain stop valve and a second drain valve provided on the second drain pipe.

[0019] (3) Beneficial effects

[0020] The beneficial effects of the present invention are:

[0021] The present invention provides a supercritical steam turbine heating system, which adjusts the parameters of the main steam and reheated steam respectively 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 meet the requirements. The main steam heating pipeline and the reheated steam heating pipeline are then connected to the main heating pipe through a heating tee joint. During heating, according to the load of the supercritical steam turbine unit, the main steam heating pipeline or the reheated steam heating pipeline is selected for heating. This can not only eliminate the impact of the decline in the efficiency of the intermediate pressure cylinder under low load of the unit, but also ensure the economy of heating under high load of the unit, thereby improving the utilization efficiency of energy, and the heating of the two pipelines can serve as backup heat sources for each other to ensure the provision of a continuous and stable heat source. Compared with the existing technology, it not only meets the needs, has a simple structure, high energy efficiency, but also can provide a continuous and stable heat source. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the connection structure of a supercritical steam turbine heating system in a specific embodiment of the present invention;

[0023] Figure 2 Schematic diagram of the connection structure of the first gate valve and the bypass and the second gate valve and the bypass in a specific embodiment of the present invention;

[0024] Figure 3 Schematic diagram of the connection structure of the third gate valve and the bypass in a specific embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the connection structure of the first desuperheating water component in a specific embodiment of the present invention;

[0026] Figure 5 Schematic diagram of the connection structure of the first hydrophobic pipeline in a specific embodiment of the present invention.

[0027] [Description of Reference Numerals]

[0028] 100: Main steam outlet pipe; 101: Main steam tee; 102: Main steam branch pipe; 103: Main steam main pipe; 104: Main steam stop valve; 105: Main steam regulating valve; 106: First gate valve and bypass; 107: Second gate valve and bypass; 108: Main steam desuperheater and pressure reducer; 109: First flowmeter; 110: First heating gate valve; 111: Main steam heating pipe; 112: First drain pipe; 113: First gate valve; 114: First bypass stop valve; 115: Second gate valve; 116: Second bypass stop valve; 117: Main steam trap; 118: First trap stop valve; 119: First trap; 120: Heating bypass stop valve;

[0029] 200: Reheat steam outlet pipe; 201: Reheat steam tee; 202: Reheat steam branch pipe; 203: Reheat steam main pipe; 204: Reheat steam stop valve; 205: Reheat steam regulating valve; 206: Reheat steam check valve; 207: Third gate valve and bypass; 208: Reheat steam trap; 209: Reheat steam desuperheater and pressure reducer; 210: Second flowmeter; 211: Second heating gate valve; 212: Reheat steam heating pipe; 213: Second drain pipe; 214: Third gate valve; 215: Third bypass stop valve;

[0030] 300: desuperheating water pipeline; 301: desuperheating water tee joint; 302: first desuperheating water assembly; 303: second desuperheating water assembly; 304: first desuperheating water electric stop valve; 305: first desuperheating water filter; 306: first desuperheating water electric regulating valve; 307: first desuperheating water check valve;

[0031] 400: Main heating pipe; 401: Safety valve; 402: Heating tee joint;

[0032] 500: boiler; 501: high-pressure cylinder; 502: medium-pressure cylinder; 503: low-pressure cylinder; 504: feedwater pump turbine; 505: feedwater pump; 506: condenser. DETAILED DESCRIPTION

[0033] 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. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0034] like Figure 1-Figure 5As shown, a specific embodiment of the present invention provides a supercritical steam turbine heating system, the core of which is a multi-heating channel composed of a main steam heating pipeline and a reheat steam heating pipeline. According to the load of the supercritical steam turbine unit, the main steam heating pipeline or the reheat steam heating pipeline can be selected for heating. The two heating pipelines can serve as backup heat sources for each other, improving energy utilization efficiency while ensuring the provision of a continuous and stable heat source. The heating system specifically includes a boiler 500 for producing main steam and reheat steam, a supercritical steam turbine unit, a main steam heating pipeline that can be selectively turned on and off, a reheat steam heating pipeline that can be selectively turned on and off, and a main heating pipe 400. The supercritical steam turbine unit includes a high-pressure cylinder 501 and an intermediate-pressure cylinder 502. The steam inlet of the high-pressure cylinder 501 is connected to the main steam pipe 103, and the steam inlet of the intermediate-pressure cylinder 502 is connected to the reheat steam pipe 203. The steam outlet of the main steam outlet pipe 100 of the boiler 500 is connected to the steam inlet of the main steam heating pipeline and the steam inlet of the main steam main pipe 103 via the main steam tee 101. The steam outlet of the high-pressure cylinder 501 is connected to the steam inlet of the boiler 500. The steam outlet of the reheat steam outlet pipe 200 of the boiler 500 is connected to the steam inlet of the reheat steam heating pipeline and the steam inlet of the reheat steam main pipe 203 via the reheat steam tee 201. The steam outlets of the main steam heating pipeline and the reheat steam heating pipeline are connected to the steam inlet of the main heating pipe 400 via the heating tee 402. The main heating pipe 400 is equipped with a safety valve 401. During heating, depending on the load of the supercritical steam turbine unit, either the main steam supply line or the reheat steam supply line is selected. When the load of the supercritical steam turbine unit exceeds 80% of its rated power, the reheat steam supply line is opened and the main steam supply line is disconnected, and the reheat steam supply line is used for heating. When the load of the supercritical steam turbine unit is less than 70% of its rated power, the main steam supply line is opened and the reheat steam supply line is disconnected, and the main steam supply line is used for heating. When the load of the supercritical steam turbine unit is between 70% and 80% of its rated power, either heating line can be used. The heat flow rate in the total heating pipe 400 is 40-100 t / h, the temperature is 400-500°C, and the pressure is 3.4-4.5 MPa.

[0035] Specifically, in this heating system, a portion of the main steam and reheated steam is separated for heating through the main steam supply pipeline and the reheated steam supply pipeline. The parameters of the main steam and reheated steam are adjusted through the main steam supply pipeline and the reheated steam supply pipeline, respectively, so that the parameters of the main steam and reheated steam meet the requirements. The main steam supply pipeline and the reheated steam supply pipeline are then connected to the main heating pipe 400 through a heating tee joint 402. During heating, the main steam supply pipeline or the reheated steam supply pipeline is selected according to the load of the supercritical steam turbine unit. This can not only eliminate the impact of the reduced efficiency of the intermediate pressure cylinder 502 under low load of the unit, but also ensure the economic efficiency of heating under high load of the unit, thereby improving energy utilization efficiency. The two pipelines can serve as backup heat sources for each other, ensuring the provision of a continuous and stable heat source. Compared with the existing technology, this meets the requirements, has a simple structure, high energy efficiency, and can also provide a continuous and stable heat source.

[0036] Furthermore, if Figure 1 As shown, the supercritical steam turbine heating system provided by the specific embodiment of the present invention also includes a feedwater pump 505 and a desuperheating water pipeline 300. The first water outlet of the feedwater pump 505 is connected to the water inlet of the boiler 500 through the main feedwater pipeline. The desuperheating water pipeline 300 includes a desuperheating water pipe, a main steam desuperheating water pipe, and a reheated steam desuperheating water pipe. The water inlet end of the desuperheating water pipe is connected to the second water outlet of the feedwater pump 505, and the water outlet end of the desuperheating water pipeline 300 is connected to the water inlet end of the main steam desuperheating water pipe and the water inlet end of the reheated steam desuperheating water pipe respectively through a desuperheating water tee joint 301. The water outlet end of the main steam desuperheating water pipe is connected to the main steam heating pipeline for cooling and reducing the pressure of the main steam. The water outlet end of the reheated steam desuperheating water pipe is connected to the reheated steam heating pipeline for cooling and reducing the pressure of the reheated steam.

[0037] Furthermore, if Figure 1 and Figure 4As shown, a first attemperating water assembly 302 is provided on the main steam attemperating water pipe, and a second attemperating water assembly 303 is provided on the reheat steam attemperating water pipe. The first attemperating water assembly 302 includes a first attemperating water electric stop valve 304, a first attemperating water filter 305, a first attemperating water electric regulating valve 306, and a first attemperating water check valve 307, arranged in sequence according to the attemperating water flow direction. The second attemperating water assembly 303 includes a second attemperating water electric stop valve, a second attemperating water filter, a second attemperating water electric regulating valve, and a second attemperating water check valve, arranged in sequence according to the attemperating water flow direction. The first attemperating water assembly 302 and the second attemperating water assembly 303 respectively control the quality and flow of the main steam attemperating water (attemperating water for the main steam) and the reheat steam attemperating water (attemperating water for the reheat steam), thereby improving the lifespan of the main steam heating pipeline and the reheat steam heating pipeline, as well as the efficiency of the main steam attemperating water and the reheat steam attemperating water. The first attemperation water electric stop valve (304) controls the flow and sealing of the main steam attemperation water. The first attemperation water filter 305 reduces the hardness of the main steam attemperation water to prevent mineral deposits from forming on the inner wall of the main steam pipe, which affects the main steam flow rate and shortens the pipe life. The first attemperation water electric regulating valve 306 controls the flow rate of the main steam attemperation water to improve the use efficiency of the main steam attemperation water. The first attemperation water check valve 307 prevents the main steam attemperation water from flowing back. Similarly, the second electric stop valve controls the flow and sealing of the reheat steam attemperation water. The second attemperation water filter reduces the hardness of the reheat steam attemperation water to prevent mineral deposits from forming on the inner wall of the reheat steam pipe, which affects the reheat steam flow rate and shortens the pipe life. The second attemperation water electric regulating valve controls the flow rate of the reheat steam attemperation water to improve the use efficiency of the reheat steam attemperation water. The second attemperation water check valve prevents the reheat steam attemperation water from flowing back.

[0038] Further, if Figure 1 As shown, the main steam heating pipeline includes a main steam branch pipe 102, a main steam desuperheater and pressure reducer 108, and a main steam heating pipe 111, which are connected in sequence. The steam inlet of the main steam branch pipe 102 is connected to the main steam tee 101, and the steam outlet of the main steam heating pipe 111 is connected to the heating tee 402. A first gate valve and bypass 106, a second gate valve and bypass 107 are sequentially installed on the main steam branch pipe 102. A first flowmeter 109 and a first heating gate valve 110 are sequentially installed on the main steam heating pipe 111. The first heating gate valve 110 is also equipped with a heating bypass and a heating bypass stop valve 120 on the heating bypass to facilitate opening and closing of the first heating gate valve 110. The outlet of the main steam desuperheater water pipe is connected to the main steam desuperheater and pressure reducer 108, which reduces the temperature and pressurizes the high-temperature, high-pressure main steam to meet the steam parameter requirements of the heat user. The main steam flow in the main steam heating pipe 111 is measured by the first flow meter 109, so as to control the main steam flow as needed.

[0039] Specifically, the main steam heating pipe 111 is connected to the reheat steam heating pipe and the main heating pipe 400 via a heating tee 402. When the reheat steam heating pipe is used for heating, the reheated steam will reversely warm the main steam heating pipe 111, causing the main steam heating pipe 111 and its valves and other structures to slowly heat up to near the operating temperature, placing it in a hot standby state. Similarly, the main steam branch pipe 102 also needs to be in a hot standby state. The first gate valve and bypass 106 and the second gate valve and bypass 107 function to flexibly and precisely control the small amount of main steam entering the main steam branch pipe 102, allowing the main steam branch pipe 102 to slowly heat up to near the operating temperature and maintain it at a near-operating temperature. Placing the steam pipe in a hot standby state before steam is introduced is called warming the pipe. This prevents the sudden introduction of a large amount of high-temperature, high-pressure steam into a cold steam pipe, which could cause significant thermal stress on the pipes, valves, and other structures, potentially damaging the steam pipe. When steam enters a cold steam pipe, condensation will be generated on the inner wall of the steam pipe, causing severe water hammer and causing the pipe to fall off the frame or be damaged.

[0040] Further, if Figure 2 As shown, the first gate valve and bypass 106 includes a first gate valve 113 and a first bypass connecting the sections of the main steam branch 102 on either side of the first gate valve 113. Two first bypass stop valves 114 are installed on the first bypass. The second gate valve and bypass 107 includes a second gate valve 115 and a second bypass connecting the sections of the main steam branch 102 on either side of the second gate valve 115. Two second bypass stop valves 116 are installed on the second bypass. The second bypass section between the two second bypass stop valves 116 also connects to the main steam trap, which is equipped with a main steam trap 117. Because a large pressure differential exists on both sides of a closed gate valve in a high-pressure steam pipeline, it can easily cause it to become stuck and generate excessive opening torque. By installing bypasses and bypass stop valves on the steam pipelines on both sides of the gate valves, the bypass stop valves can be opened to pressurize the non-pressurized pipe section before the gate valves are opened, reducing the pressure differential and lowering the resistance to opening the gate valves. This facilitates the opening and closing of the first gate valve 113 and the second gate valve 115. The main steam trap promptly drains condensate from the main steam branch pipe 102. This prevents condensate from accumulating in the pipes, which could be rapidly lifted by the main steam and cause water hammer, impacting the pipe walls and valves, potentially damaging the pipes or even causing personal injury. The main steam trap 117's primary function is to block steam and drain water (blocking steam and draining water), preventing main steam leakage and conserving steam. The discharged condensate can be drained or recycled as needed.

[0041] Further, if Figure 1As shown, the reheated steam heating pipeline includes a reheated steam branch pipe 202, a reheated steam desuperheater 209, and a reheated steam heating pipe 212, which are connected in sequence. The steam inlet of the reheated steam branch pipe 202 is connected to the reheated steam tee 201, and the steam outlet of the reheated steam heating pipe 212 is connected to the heating tee 402. The reheated steam branch pipe 202 is equipped with a third gate valve and a bypass 207. The reheated steam heating pipe 212 is sequentially equipped with a second flowmeter 210 and a second heating gate valve 211. The outlet of the reheated steam desuperheating water pipe is connected to the reheated steam desuperheater 209. The reheated steam, which is relatively high temperature and high pressure, is desuperheated and pressurized by the reheated steam desuperheater 209 to meet the steam parameter requirements of the heat user. The reheated steam flow rate in the reheated steam heating pipe 212 is measured by the second flowmeter 210, facilitating the control of the reheated steam flow rate as needed. The third gate valve and the bypass 207 facilitate flexible control of the reheat steam branch pipe 202 for pipe warming. A reheat steam check valve 206 is also provided on the reheat steam branch pipe 202 to prevent the reheat steam from flowing back and affecting the reheat steam flow rate.

[0042] Furthermore, if Figure 3 As shown, the third gate valve and bypass 207 includes a third gate valve 214 and a third bypass connecting the reheat steam branch pipe 202 on both sides of the third gate valve 214. Two third bypass stop valves 215 are installed on the third bypass. The third bypass section between the two third bypass stop valves 215 is also connected to the reheat steam drain pipe, which is equipped with a reheat steam trap 208. The third bypass and the third bypass stop valve 215 facilitate the opening and closing of the third gate valve 214. Condensate in the reheat steam branch pipe 202 is promptly drained through the reheat steam trap to avoid damage to the pipe or even personal injury. The reheat steam trap 208 blocks steam and drains water, preventing reheat steam leakage.

[0043] Furthermore, if Figure 1 As shown, the main steam main pipe 103 is provided with a main steam stop valve 104 and a main steam regulating valve 105, sequentially arranged along the main steam flow direction. The reheat steam main pipe 203 is provided with a reheat steam stop valve 204 and a reheat steam regulating valve 205, sequentially arranged along the reheat steam flow direction. The main steam stop valve 104 controls the flow of main steam into the high-pressure cylinder 501. The main steam regulating valve 105 controls the flow rate of main steam into the high-pressure cylinder 501. The reheat steam stop valve 204 controls the flow of reheat steam into the intermediate-pressure cylinder 502. The reheat steam regulating valve 205 controls the flow rate of reheat steam into the intermediate-pressure cylinder 502.

[0044] Furthermore, if Figure 1 and Figure 5As shown, the main steam heating pipe 111 is connected to a first drain pipe 112. This first drain pipe 112 comprises a first drain pipe, a first drain stop valve 118, and a first drain valve 119. The first drain pipe 112 is used to drain condensate formed after the main steam is desuperheated and depressurized. The first stop valve controls the opening and closing of the first drain pipe 112. The first drain valve 119 blocks steam and drains water, preventing leakage of heating steam from the main steam heating pipe 111.

[0045] Furthermore, if Figure 1 As shown, the reheated steam heating pipe 212 is connected to a second drain line 213. This second drain line 213 includes a second drain pipe, a second drain stop valve, and a second drain valve. The second drain line 213 is opened and closed by the second stop valve. The second drain valve blocks steam and drains water, preventing leakage of heating steam from the reheated steam heating pipe 212.

[0046] Furthermore, if Figure 1 As shown, the heating system also includes a condenser 506 and a feedwater pump turbine 504. The turbine also includes a low-pressure cylinder 503. The first steam outlet of the intermediate-pressure cylinder 502 is connected to the steam inlet of the low-pressure cylinder 503, which in turn is connected to the first steam inlet of the condenser 506. The second steam outlet of the intermediate-pressure cylinder 502 is connected to the steam inlet of the feedwater pump turbine 504, which in turn is connected to the second steam inlet of the condenser 506. The function of the condenser 506 is to condense the exhaust steam from the low-pressure cylinder 503 and the feedwater pump turbine 504 into water for reuse by the boiler 500, forming a circulation system. The feedwater pump turbine 504 is used to drive the feedwater pump 505, which meets the water supply requirements of the boiler 500 and the desuperheating water pipeline 300.

[0047] Specifically, a 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. Figure 1 As shown, the boiler 500 passes the high-temperature, high-pressure main steam it produces into the high-pressure cylinder 501 to produce work. The high-pressure cylinder 501 then passes the completed main steam into the boiler 500 for reheating. The boiler 500 then passes the reheated steam into the intermediate-pressure cylinder 502 to continue producing work. The intermediate-pressure cylinder 502 then passes the completed reheated steam into the low-pressure cylinder 503 to continue producing work. Finally, the low-pressure cylinder 503 passes the exhaust steam into the condenser 506. This step-by-step process improves energy utilization. The turbine rotor drives the generator rotor through a coupling to generate electricity.

[0048] Preferably, both the main steam desuperheater and pressure reducer 108 and the reheat steam desuperheater and pressure reducer 209 are split-type desuperheaters, with desuperheating and pressure reduction performed separately, using separate pressure reducing valves. Split-type desuperheaters offer high control accuracy, stable operation, and sensitive adjustment, effectively eliminating the effects of static errors.

[0049] The supercritical steam turbine heating system provided by the specific embodiment of the present invention has the following specific working conditions: first, the main steam stop valve 104 and the main steam regulating valve 105 are opened, the main steam main pipe 103 is connected, and the high-temperature and high-pressure main steam produced by the boiler 500 is passed into the high-pressure cylinder 501 through the main steam main pipe 103 to perform work. The high-pressure cylinder 501 passes the finished main steam into the boiler 500 for reheating to produce reheated steam, opens the reheat steam stop valve 204 and the reheat steam regulating valve 205, connects the reheat steam main pipe 203, and passes the reheated steam into the intermediate pressure cylinder 502 through the reheat steam main pipe 203 to continue the subsequent work process of the supercritical steam turbine. A small amount of main steam is then directed through the first bypass stop valve 114 and the second bypass stop valve 116 to warm up the main steam branch pipe 102. A small amount of reheat steam is directed through the third bypass stop valve 215 to warm up the reheat steam branch pipe 202, keeping both the main steam branch pipe 102 and the reheat steam branch pipe 202 in a hot standby state. The main steam heating pipe 111 is then warmed up. After warming up is complete, the first gate valve 113 and the second gate valve 115 are opened to open the main steam branch pipe 102, allowing the main steam to flow into the main steam branch pipe 102 and into the main steam desuperheater and pressure reducer 108. The main steam drain valve 117 is then opened to open the main steam drain pipe for timely drainage. At the same time, the first electric regulating valve 306 controls the flow of desuperheated water from the main steam desuperheating water pipe into the main steam desuperheating and pressure reducing device 108. This reduces the temperature of the main steam to 400-500°C and the pressure to 3.5-4.5 MPa. The resulting heating steam is then passed into the main steam heat supply pipe 111. The first drain stop valve 118 and the first drain valve 119 are opened, connecting the first drain pipe 112 to drain water immediately. The heating steam flow rate is monitored by the first flowmeter 109 to facilitate timely adjustments. The first heat supply gate valve 110 is opened, connecting the main steam heat supply pipe 111, allowing the heating steam to flow into the main heat supply pipe 400 to provide heat to users. The reheat steam heat supply pipe 212 is heated and put into hot standby mode. During the main steam heating process, when the supercritical steam turbine load exceeds 80% of its rated power, the third gate valve 214 is first opened, opening the reheat steam branch pipe 203 and passing the reheated steam into the reheat steam desuperheater 209. The reheat steam drain valve 208 is then opened, opening the reheat steam drain pipe for timely drainage. Simultaneously, the second desuperheating water electric regulating valve controls the flow of desuperheated water from the reheat steam desuperheater 209 into the reheat steam desuperheater 209. This controls the reheat steam desuperheater 209 to reduce the reheated steam temperature to 400-500°C and the pressure to 3.5-4.5 MPa before it is passed into the main heat supply pipe 400.When the reheated steam is cooled and decompressed, the main steam flow in the main steam branch 102 is gradually reduced by controlling the first bypass stop valve 114 and the second bypass stop valve 116. After the reheated steam parameters are cooled and decompressed to the required parameters, the main steam branch 102 is closed by the first gate valve 113 and the second gate valve 115, and the reheated steam is used for heating. The main steam heating pipe 111 is maintained in a hot standby state under the action of the heating steam. In the process of using reheated steam for heating, when the load of the supercritical steam turbine unit is lower than 70% of its rated power, the main steam is first passed into the main steam cooling and decompression device 108. While the main steam is cooled and decompressed, the reheated steam flow in the reheated steam branch 202 is gradually reduced. After the main steam parameters are cooled and decompressed to the required parameters, the reheated steam branch 202 is closed. In this way, a stable heat source is provided.

[0050] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0051] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0052] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A supercritical steam turbine heating system, characterized in that: It comprises a boiler (500) for producing main steam and reheat steam, a supercritical steam turbine unit, a main steam heating pipeline that can be selectively switched on and off, a reheat steam heating pipeline that can be selectively switched on and off, and a main heating pipe (400); The supercritical steam turbine unit includes a high-pressure cylinder (501) and an intermediate-pressure cylinder (502), wherein the steam inlet of the high-pressure cylinder (501) is connected to a main steam pipe (103), and the steam inlet of the intermediate-pressure cylinder (502) is connected to a reheat steam pipe (203); The steam outlet end of the main steam outlet pipe (100) of the boiler (500) is connected to the steam inlet end of the main steam heating pipeline and the steam inlet end of the main steam pipe (103) through the main steam tee joint (101), and the steam outlet of the high-pressure cylinder (501) is connected to the steam inlet of the boiler (500); The steam outlet end of the reheat steam outlet pipe (200) of the boiler (500) is connected to the steam inlet end of the reheat steam heating pipeline and the steam inlet end of the reheat steam main pipe (203) respectively through the reheat steam tee joint (201); The steam outlet end of the main steam heating pipeline and the steam outlet end of the reheat steam heating pipeline are connected to the steam inlet end of the main heating pipe (400) through a heating tee joint (402); When the load of the supercritical steam turbine unit exceeds 80% of its rated power, the reheat steam heating pipeline is connected and the main steam heating pipeline is disconnected, and the reheat steam heating pipeline is used for heating; When the load of the supercritical steam turbine unit is lower than 70% of its rated power, the main steam heating pipeline is opened and the reheat steam heating pipeline is disconnected, and the main steam heating pipeline is used for heating; The main steam heating pipeline includes a main steam branch pipe (102), a main steam temperature and pressure reducing device (108) and a main steam heating pipe (111) which are connected in sequence; The steam inlet end of the main steam branch pipe (102) is connected to the main steam tee joint (101), and the steam outlet end of the main steam heating pipe (111) is connected to the heating tee joint (402); A first gate valve and a bypass (106) and a second gate valve and a bypass (107) are sequentially provided on the main steam branch pipe (102); A first flow meter (109) and a first heating gate valve (110) are sequentially arranged on the main steam heating pipe (111); The reheat steam heating pipeline includes a reheat steam branch pipe (202), a reheat steam temperature and pressure reducing device (209), and a reheat steam heating pipe (212) which are connected in sequence; The steam inlet end of the reheat steam branch pipe (202) is connected to the reheat steam tee joint (201), and the steam outlet end of the reheat steam heating pipe (212) is connected to the heating tee joint (402); The reheat steam branch pipe (202) is provided with a third gate valve and a bypass (207); the reheat steam heating pipe (212) is provided with a second flow meter (210) and a second heating gate valve (211) in sequence.

2. The supercritical steam turbine heating system according to claim 1, characterized in that: The first gate valve and bypass (106) includes a first gate valve (113) and a first bypass communicating with the main steam branch pipe (102) on both sides of the first gate valve (113), and two first bypass stop 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 pipe (102) on both sides of the second gate valve (115), and two second bypass stop valves (116) are provided on the second bypass. The second bypass portion between the two second bypass stop valves (116) is also connected to a main steam drain pipe, on which a main steam drain valve (117) is provided.

3. The supercritical steam turbine heating system according to claim 1, wherein: The third gate valve and bypass (207) includes a third gate valve (214) and a third bypass communicating with the reheat steam branch pipe (202) on both sides of the third gate valve (214), and two third bypass stop valves (215) are provided on the third bypass. The third bypass portion between the two third bypass stop valves (215) is also connected to a reheat steam drain pipe, and a reheat steam drain valve (208) is provided on the reheat steam drain pipe.

4. The supercritical steam turbine heating system according to claim 1, wherein: It also includes a water supply pump (505) and a desuperheating water pipeline (300), wherein a first water outlet of the water supply pump (505) is connected to a water inlet of the boiler (500) through a main water supply pipeline; The attemperating water pipeline (300) comprises an attemperating water pipe, a main steam attemperating water pipe and a reheat steam attemperating water pipe; the water inlet of the attemperating water pipe is connected to the second water outlet of the feed water pump (505), and the water outlet of the attemperating water pipeline (300) is connected to the water inlet of the main steam attemperating water pipe and the water inlet of the reheat steam attemperating water pipe respectively through an attemperating water tee joint (301); The outlet end of the main steam cooling water pipe is connected to the main steam heating pipeline for cooling and reducing the pressure of the main steam; the outlet end of the reheat steam cooling water pipe is connected to the reheat steam heating pipeline for cooling and reducing the pressure of the reheat steam.

5. The supercritical steam turbine heating system according to claim 4, characterized in that: A first cooling water component (302) is provided on the main steam cooling water pipe, and a second cooling water component is provided on the reheat steam cooling water pipe; The first cooling water component (302) includes a first cooling water electric stop valve (304), a first cooling water filter (305), a first cooling water electric regulating valve (306) and a first cooling water check valve (307) which are sequentially arranged according to the flow direction of the cooling water; The second cooling water assembly (303) comprises a second cooling water electric stop valve, a second cooling water filter, a second cooling water electric regulating valve and a second cooling water check valve, which are sequentially arranged according to the flow direction of the cooling water.

6. The supercritical steam turbine heating system according to claim 1, characterized in that: A main steam stop valve (104) and a main steam regulating valve (105) are sequentially arranged on the main steam main pipe (103) according to the main steam flow direction; A reheat steam stop valve (204) and a reheat steam regulating valve (205) are sequentially arranged on the reheat steam main pipe (203) according to the flow direction of the reheat steam.

7. The supercritical steam turbine heating system according to claim 1, characterized in that: The main steam heating pipe (111) is connected to a first drain pipe (112), and the first drain pipe (112) includes a first drain pipe, a first drain stop valve (118) and a first drain valve (119) arranged on the first drain pipe.

8. The supercritical steam turbine heating system according to claim 1, wherein: The reheat steam heating pipe (212) is connected to a second drain pipe (213), and the second drain pipe (213) comprises a second drain pipe, a second drain stop valve and a second drain valve arranged on the second drain pipe.

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