A condensing steam turbine exhaust steam recovery system
By introducing a high back-pressure waste steam condenser, a booster turbine condenser, and a heat network heater into the condensing steam turbine waste steam recovery system, combined with energy storage heat exchange and domestic hot water supply, the problem of the condensing steam turbine waste steam recovery system being idle during the non-heating season has been solved, enabling efficient utilization of waste steam energy throughout the year and improving the unit's peak-shaving capacity and cogeneration benefits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENMU ELECTROCHEMICAL DEV CO LTD OF SHAANXI COAL CHEM IND GRP
- Filing Date
- 2026-06-10
- Publication Date
- 2026-07-31
AI Technical Summary
The waste steam recovery system of condensing steam turbines is idle during the non-heating season, resulting in the waste of low-grade residual energy. Furthermore, it loses an effective way to regulate heating and change the unit's electrical output during the non-heating season, affecting the unit's peak-shaving capacity.
A condensing steam turbine waste steam recovery system was designed, including a waste steam recovery unit, a heating network unit, and a peak-shaving unit for non-heating seasons. The system achieves cascade utilization through a high back-pressure waste steam condenser, a booster turbine condenser, and a heating network heater. Combined with energy storage heat exchange and domestic hot water heating, it breaks through seasonal barriers and achieves efficient recovery of waste steam energy throughout the year.
It significantly reduced cold-end losses, improved the revenue of cogeneration and the peak-shaving capacity of the unit, reduced coal consumption and pollutant emissions, and achieved deep peak shaving and low-cost heating throughout the year.
Smart Images
Figure CN122485656A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of waste energy recovery technology, specifically to a condensing steam turbine waste steam recovery system. Background Technology
[0002] Driven by the "dual carbon" goals, the power industry urgently needs to optimize its energy structure by deeply exploring the energy-saving and emission-reduction potential of existing generating units. Turbine cold-end losses are the largest source of energy loss in thermal power units, especially under high back-pressure heating conditions. If exhaust steam cannot be fully utilized and is directly emitted, it will result in a huge waste of low-grade thermal energy. Therefore, how to efficiently recover the waste energy of turbine exhaust steam under all operating conditions, while balancing power generation and heating demands, has become a key technological challenge for reducing heating costs and improving the peak-shaving capacity of generating units.
[0003] High back pressure heating technology is the mainstream method for recovering waste heat from exhaust steam. Its core lies in modifying condensing steam turbines to artificially increase the exhaust steam back pressure from vacuum to 10-30 kPa or even higher during the heating season, raising the exhaust steam saturation temperature to 65℃-80℃. The heat is then directly heated by a specially designed high back pressure condenser, thereby essentially eliminating cold source losses and achieving cascaded energy utilization.
[0004] However, the high back-pressure operation mode is strongly coupled with the heating load, and its "heat-driven power generation" characteristic has adaptability issues in the non-heating season: its design is only for winter heating conditions, and the recovery of low-grade exhaust steam relies entirely on a stable cold source provided by the heating network water. In the non-heating season, due to the lack of users, the high back-pressure condenser and the turbine condenser system are forced to shut down, and all turbine exhaust steam is switched to the air condenser, directly discharging a large amount of waste heat from the exhaust steam to the main steam turbine.
[0005] The aforementioned seasonal (nearly half the year) idle condensing turbine exhaust steam recovery system not only causes a huge waste of low-grade surplus energy, but also deprives the unit of an effective technical path to quickly and deeply change the unit's electrical output by adjusting the heating supply during the non-heating season when flexible peak shaving is required. Summary of the Invention
[0006] To address the problem presented in the background art that the seasonal idleness of condensing steam turbine exhaust steam recovery systems not only results in a huge waste of low-grade surplus energy, but also causes the unit to lose the ability to adjust heating and change the power output adjustment path during the non-heating season when flexible peak shaving is required, this invention provides a condensing steam turbine exhaust steam recovery system.
[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A condensing steam turbine exhaust steam recovery system includes an exhaust steam recovery unit, a heating network supply unit, and a peak shaving unit for non-heating seasons. The waste steam recovery unit is connected to the working steam outlet pipe of the steam turbine. The off-heating season peak shaving unit is arranged in parallel with the heating network heating unit; the off-heating season peak shaving unit or the heating network heating unit exchanges heat with the waste steam recovery unit respectively.
[0008] Furthermore, the non-heating season peak-shaving unit includes an energy storage heat exchange pipeline, an energy storage inlet water pipeline, an energy storage water tank, and an energy storage return water pipeline; The energy storage heat exchange pipeline exchanges heat with the waste steam recovery unit; One end of the energy storage water inlet pipe is connected to the outlet of the energy storage heat exchange pipe, and the other end of the energy storage water inlet pipe is connected to the hot water inlet of the energy storage tank. One end of the energy storage return water pipe is connected to the cold water outlet of the energy storage water tank, and the other end of the energy storage return water pipe is connected to the inlet of the energy storage heat exchange pipe. A second circulation pump is installed on the energy storage return water pipe.
[0009] Furthermore, the non-heating season peak-shaving unit also includes a domestic hot water pipe, a domestic hot water station heat exchanger, and a water return pipe connected in series. The heat exchanger of the domestic hot water station is connected to the hot water outlet of the energy storage tank through the domestic hot water pipeline, and the heat exchanger of the domestic hot water station is connected to the cold water return outlet of the energy storage tank through the water return pipeline. The factory's domestic water pipes exchange heat with the hot water in the heat exchanger of the domestic hot water station.
[0010] Furthermore, the energy storage tank is equipped with a temperature detection device.
[0011] Furthermore, the condensing steam turbine exhaust steam recovery system also includes a controller, the signal input terminal of which is electrically connected to a temperature detection device, and the signal output terminal of which is electrically connected to a second circulation pump.
[0012] Furthermore, the energy storage tank is equipped with a pressure detection device.
[0013] Furthermore, the energy storage tank is an atmospheric pressure thermal storage tank or a pressurized thermal storage tank.
[0014] Furthermore, the waste steam recovery unit includes a first steam turbine, a first steam turbine condenser, a high back pressure waste steam condenser, and a heat network heater; The steam inlet of the first steam generator is connected to the high-pressure cylinder extraction pipe of the No. 1 steam turbine. At the same time, the steam inlet of the first steam generator is also connected to the exhaust steam outlet pipe of the low-pressure cylinder of the No. 1 steam turbine. The steam inlet of the first steam turbine condenser is connected to the steam outlet of the first steam turbine; The inlet of the high back pressure exhaust steam condenser is connected to the exhaust steam outlet pipe of the low-pressure cylinder of the No. 1 steam turbine; The steam inlet of the heating network heater is connected to the high-pressure cylinder extraction steam pipeline of the No. 1 steam turbine; The heating network heating unit includes a heating network water supply pipeline and a heating network return water pipeline. The heating network return water in the heating network return water pipeline enters the high back pressure exhaust steam condenser, the first steam turbine condenser and the heating network heater in sequence for three-stage heating, and then is transported through the heating network water supply pipeline.
[0015] Furthermore, the waste steam recovery unit also includes a second steam turbine and a second steam turbine condenser; The steam inlet of the second steam generator is connected to the high-pressure cylinder extraction pipe of the No. 2 steam turbine. At the same time, the steam inlet of the second steam generator is also connected to the exhaust steam outlet pipe of the low-pressure cylinder of the No. 2 steam turbine. The second steam turbine condenser is connected to the exhaust port of the second steam turbine; The return water from the heating network in the return water pipeline sequentially enters the high back pressure exhaust steam condenser, the first or second steam turbine condenser, the second or first steam turbine condenser, and the heating network heater for four stages of heating, and then is transported through the heating network supply water pipeline.
[0016] Furthermore, the non-heating season peak-shaving unit also includes an air condenser, which is connected to the exhaust steam outlet pipe of the low-pressure cylinder of the steam turbine.
[0017] In summary, this invention has the following beneficial technical effects: by using a high back-pressure exhaust steam condenser, a booster turbine condenser, and a heating network heater, the waste heat of the turbine working steam is recovered to supply heat to the heating network return water, realizing the cascade utilization of the turbine working steam. In particular, it significantly reduces cold-end losses by recovering and utilizing the low-grade exhaust steam heat energy discharged from the turbine's low-pressure cylinder, thereby reducing turbine cold-end losses. At the same time, in conjunction with the heating network heating unit, it improves the plant's winter cogeneration revenue and unit peak-shaving capacity, meeting the city's winter heat load demand while reducing heating costs and improving enterprise efficiency. Meanwhile, to address the shortcomings of existing technologies, a peak-shaving unit for the non-heating season is added. During the summer, when the heating network stops supplying heat, the waste steam that was originally directly discharged is recovered and stored for a long time to provide heating for the plant's domestic water pipelines and provide domestic hot water for the plant. Alternatively, it can be used for heating during the winter heating season, realizing the utilization of waste steam heat during the non-heating season, breaking down seasonal barriers, achieving efficient recovery of waste steam energy throughout the year, and participating in deep peak shaving throughout the year. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the system structure in Example 1.
[0019] Figure 2 This is a schematic diagram of the system structure in Example 2.
[0020] Explanation of reference numerals in the attached drawings: 101, No. 1 steam turbine; 102, No. 2 steam turbine; 11, high-pressure cylinder; 12, low-pressure cylinder; 21, first booster turbine; 22, second booster turbine; 31, first booster turbine condenser; 32, second booster turbine condenser; 4, exhaust steam device; 5, air-steam condenser; 6, high back pressure exhaust steam condenser; 7, heating network heater; 8, deaerator; 91, first circulating pump; 92, second circulating pump; 10, energy storage tank; 13, domestic hot water station heat exchanger. Detailed Implementation
[0021] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the embodiments described below.
[0022] Example 1 Reference Figure 1 This embodiment 1 provides a condensing steam turbine exhaust steam recovery system, including an exhaust steam recovery unit, a heating network heating unit, and a non-heating season peak shaving unit; The waste steam recovery unit is connected to the working steam outlet pipeline of the steam turbine; The peak-shaving unit during the non-heating season is set up in parallel with the heating network unit; heat exchange takes place between the peak-shaving unit or the heating network unit and the waste steam recovery unit during the non-heating season.
[0023] Specifically, the aforementioned condensing steam turbine exhaust steam recovery system includes a No. 1 steam turbine 101. An exhaust device 4 is installed below the exhaust port of the low-pressure cylinder 12 of the No. 1 steam turbine 101. The exhaust device 4 is connected to the throat of the steam turbine and is used to collect the exhaust steam discharged from the low-pressure cylinder 12 of the No. 1 steam turbine 101. Simultaneously, as an expansion joint (compensator) to reduce pipeline thrust, it absorbs the thermal expansion of the equipment, smoothly guiding the collected exhaust steam into the exhaust steam recovery unit, ensuring stable exhaust pressure of the steam turbine.
[0024] The waste steam recovery unit includes a first turbocharger 21, a first turbocharger condenser 31, a high back pressure waste steam condenser 6, and a heat network heater 7. Specifically: The steam inlet of the first steam booster 21 is connected to the three-section extraction steam pipeline of the high-pressure cylinder 11 of the No. 1 steam turbine 101; at the same time, the steam inlet of the first steam booster 21 is also connected to the exhaust steam outlet pipeline (i.e., exhaust device 4) of the low-pressure cylinder 12 of the No. 1 steam turbine 101.
[0025] The steam inlet of the first steam turbine condenser 31 is connected to the steam outlet of the first steam turbine 21.
[0026] The inlet of the high back pressure exhaust steam condenser 6 is connected to the exhaust steam outlet pipe (i.e., exhaust device 4) of the low pressure cylinder 12 of the No. 1 steam turbine 101.
[0027] The steam inlet of the heating network heater 7 is connected to the three-section extraction steam pipeline of the high-pressure cylinder 11 of the No. 1 steam turbine 101.
[0028] The drain ports of the first turbocharger condenser 31 and the high back-pressure exhaust steam condenser 6 are both connected to the exhaust steam device 4. The exhaust steam device 4 collects the condensate flowing back from the high back-pressure exhaust steam condenser 6 and the first turbocharger condenser 31, buffering and stabilizing the water level. The drain water from the exhaust steam device 4 is further treated and then returned to the thermal system for recycling as boiler feedwater. The drain water from the heating network heater 7 goes directly to the deaerator 8 and is used as boiler feedwater.
[0029] The heating network heating unit includes a heating network water supply pipe and a heating network return water pipe, and a first circulation pump 91 is installed on the heating network water supply pipe.
[0030] During winter, under the heating network water supply pipeline operating conditions: In the initial stage of heating, users require a heating temperature below 70.5℃, and primary heating is provided only by the high back pressure exhaust steam condenser 6.
[0031] During primary heating, the return water from the heating network enters the high back pressure exhaust steam condenser 6 for heating, and then is transported through the heating network supply water pipeline.
[0032] Meanwhile, the low-grade exhaust steam discharged from the low-pressure cylinder 12 of the No. 1 steam turbine 101 first gathers in the exhaust steam device 4, and then enters the high back pressure exhaust steam condenser 6 to exchange heat with the return water of the heating network, completing the first stage of heating of the return water of the heating network. The return water of the heating network is heated to above 70.5°C, and then supplied to users for heating through the heating network water supply pipeline.
[0033] As winter temperatures drop, users require heating temperatures between 70.5-80.5℃, which is achieved through secondary heating by the high back pressure exhaust steam condenser 6 and the first booster turbine condenser 31.
[0034] During secondary heating, the return water from the heating network enters the return water pipeline of the heating network and sequentially enters the high back pressure exhaust steam condenser 6 and the first booster turbine condenser 31 for secondary heating, and then is transported through the heating network supply water pipeline.
[0035] Meanwhile, the low-grade exhaust steam discharged from the low-pressure cylinder 12 of the No. 1 steam turbine 101 is first collected in the exhaust steam device 4. One path enters the high back-pressure exhaust steam condenser 6 to complete the first stage of heating for the return water of the heating network; the other path enters the first booster turbine 21 to mix with the high-grade steam entering the first booster turbine 21 from the high-pressure cylinder 11 of the No. 1 steam turbine 101 to form medium-grade steam. Then, the medium-grade steam enters the first booster turbine condenser 31 to exchange heat with the return water of the heating network, completing the second stage of heating for the return water of the heating network. The temperature of the return water of the heating network rises to above 80.5°C, and then it is supplied to users for heating through the heating network water supply pipeline.
[0036] As winter temperatures continue to drop, users require heating temperatures between 80.5-90℃, which is achieved through a three-stage heating process consisting of a high back-pressure exhaust steam condenser 6, a first booster turbine condenser 31, and a heating network heater 7.
[0037] During the three-stage heating process, the return water from the heating network in the return water pipeline sequentially enters the high back pressure exhaust steam condenser 6, the first booster turbine condenser 31, and the heating network heater 7 for three-stage heating, and is then delivered to users for heating via the heating network supply water pipeline.
[0038] Meanwhile, the low-grade exhaust steam discharged from the low-pressure cylinder 12 of turbine 101 first gathers in the exhaust device 4, and then enters the high back-pressure exhaust steam condenser 6 to exchange heat with the return water of the heating network, completing the first stage of heating of the return water to above 70.5℃. The low-grade exhaust steam also enters the first booster turbine 21, where it mixes with the high-grade steam from the high-pressure cylinder 11 of turbine 101, which also enters the first booster turbine 21, to form medium-grade steam. Medium-grade steam then enters the condenser 31 of the first turbine, where it exchanges heat with the return water of the heating network, completing the secondary heating of the return water to above 80.5℃. High-grade steam extracted from the high-pressure cylinder 11 of the No. 1 turbine directly enters the heater 7 of the heating network, where it exchanges heat with the return water of the heating network, completing the tertiary heating of the return water to above 90℃. The return water is then supplied to users for heating through the heating network water supply pipeline.
[0039] The above-mentioned high-back-pressure exhaust steam condenser 6, first turbine condenser 31, and heat network heater 7 recover the waste heat of the turbine working steam to supply heat to the heat network return water, realizing the cascade utilization of the turbine working steam. In particular, it significantly reduces the cold end loss by recovering and utilizing the heat energy that was originally lost directly through the air condenser. At the same time, in conjunction with the heat network heating unit, it improves the plant's winter cogeneration revenue and unit peak-shaving capacity, meeting the city's winter heat load demand while reducing heating costs and improving enterprise efficiency.
[0040] During summer, when the heating network water supply pipeline stops supplying heat and the return water temperature of the heating network is high, the existing system switches all the exhaust steam from the steam turbine to the air-steam condenser 5. The air-steam condenser 5 operates at full load, directly discharging a large amount of waste heat from the exhaust steam to the main steam. This not only causes a huge waste of low-grade waste energy, but also deprives the unit of an effective technical path to quickly and deeply change the unit's electrical output by adjusting the heating supply during the non-heating season when flexible peak shaving is required.
[0041] In this invention, an air condenser 5 is installed in the exhaust steam outlet pipe of the low-pressure cylinder of the condensing steam turbine. Specifically, the steam inlet of the air condenser 5 is connected to the exhaust steam outlet pipe (i.e., exhaust device 4) of the low-pressure cylinder 12 of the No. 1 steam turbine 101, and the drain outlet of the air condenser 5 is also connected to the exhaust device 4. The air condenser 5 is used to cool and dissipate heat from the exhaust steam of the steam turbine when the heating network water supply pipeline stops supplying heat during summer.
[0042] In order to utilize the thermal energy of the steam turbine working steam during summer, this invention adds a peak-shaving unit for the non-heating season.
[0043] Specifically, the peak shaving unit during the non-heating season includes an energy storage heat exchange pipeline, an energy storage inlet water pipeline, an energy storage water tank 10, and an energy storage return water pipeline. The energy storage heat exchange pipeline exchanges heat with the waste steam recovery unit. One end of the energy storage water inlet pipe is connected to the outlet of the energy storage heat exchange pipe, and the other end of the energy storage water inlet pipe is connected to the hot water inlet of the energy storage water tank 10; the energy storage water inlet pipe transports the heated hot water, and the energy storage water tank 10 stores the heated hot water. One end of the energy storage return water pipe is connected to the cold water outlet of the energy storage water tank 10, and the other end of the energy storage return water pipe is connected to the inlet of the energy storage heat exchange pipe. A second circulation pump 92 is installed on the energy storage return water pipe. The energy storage return water pipe returns the cooled water to the waste steam recovery unit for circulation heating.
[0044] During summer, when the heating network's water supply pipelines cease operation, the previously directly emitted waste steam is recovered and stored long-term using the energy storage characteristics of the energy storage tank 10. This stored energy is then used for heating during the winter heating season, shaving and filling peak loads for the power grid units. This allows for the utilization of waste steam heat during the non-heating season, breaking down seasonal barriers and achieving efficient year-round recovery of waste steam energy for deep peak shaving throughout the year. Simultaneously, it reduces the cooling flow rate of the air-steam condenser, thereby reducing the power consumption of the air-steam condenser fan. This not only saves on plant power consumption and reduces the total annual coal consumption, but also, due to the reduction in coal consumption and boiler flue gas volume, correspondingly reduces boiler flue gas emissions, thus reducing emissions of pollutants such as CO2, sulfides, nitrogen oxides, and particulate matter.
[0045] In the energy storage tank 10, due to differences in water temperature, the water density varies, causing the water to stratify according to density: hot water on top, cold water at the bottom, with a transition layer in between. Based on this water stratification principle, the energy storage tank 10 utilizes heated water to store the waste heat from the exhaust steam. Specifically: During periods of low electricity load and low electricity prices, the exhaust steam from the turbine is used to circulate and heat the water in the energy storage tank 10, storing the heat energy from the exhaust steam through the water. During heat storage, the energy storage heat exchange pipes exchange heat with the exhaust steam recovery unit, and the energy storage inlet pipes transport the heated hot water. The hot water enters the water distributor at the top of the energy storage tank 10, ensuring a uniform water flow rate and preventing the mixing of hot and cold water layers within the tank. Simultaneously, a volume of low-temperature water at the bottom flows out through the water distributor at the bottom of the tank 10 into the energy storage return water pipe. The return water pipe returns the cooled water to the exhaust steam recovery unit for recirculation and heating until the hot water reaches the predetermined temperature. During the heat storage process, the transition layer gradually descends from top to bottom within the hot water storage tank until it completely disappears, at which point the tank is entirely filled with hot water, and the heat storage process is complete.
[0046] During peak electricity consumption periods and periods of high electricity prices, the extraction of steam from the steam turbine is reduced or stopped, and the heat stored in the hot water in the energy storage tank 10 is directly used to supply energy-consuming equipment. During heat release, the hot water with a higher temperature in the energy storage tank 10 flows out through the water distributor at the bottom of the energy storage tank 10. During this process, the transition layer gradually rises from bottom to top in the hot water storage tank until it disappears completely. At this time, the energy storage tank 10 is filled with low-temperature return water, and the heat release process ends. By using the mode of storing heat during off-peak hours and supplying heat during peak hours, off-peak electricity prices can be utilized to significantly save on electricity costs. Therefore, deep peak shaving is achieved during the summer. Combined with the peak shaving of the heating network unit during the winter hours, deep peak shaving can be achieved throughout the year.
[0047] The peak-shaving unit during the non-heating season also includes a domestic hot water station, which is used as an energy-consuming device. The domestic hot water station specifically includes a domestic hot water pipeline, a domestic hot water station heat exchanger 13, and a water return pipeline connected in series. The domestic hot water station heat exchanger 13 is connected to the hot water outlet of the energy storage tank 10 through the domestic hot water pipeline, and the domestic hot water station heat exchanger 13 is connected to the cold water return outlet of the energy storage tank 10 through the water return pipeline. Water heated by the waste steam recovery unit enters the domestic hot water station heat exchanger 13 through the domestic hot water pipeline. The water heated by the waste steam recovery unit flows in the tube side or shell side of the domestic hot water station heat exchanger 13, while domestic water flows in the shell side or tube side of the domestic hot water station heat exchanger 13. By using the water heated by the waste steam recovery unit to heat domestic water, the plant provides convenience for domestic hot water while improving the thermal energy utilization of the waste steam recovery unit, thus achieving deep peak shaving during the summer.
[0048] The energy storage tank 10 is preferably an atmospheric pressure energy storage tank or a pressurized energy storage tank. The temperature of the hot water stored in an atmospheric pressure energy storage tank is typically below 98°C, while the temperature of the hot water stored in a pressurized energy storage tank 10 is typically below 120°C. In this embodiment 1, the domestic hot water temperature is typically below 98°C, so an atmospheric pressure energy storage tank is preferred. Atmospheric pressure energy storage tanks have a simple structure, low cost, are easy to maintain, and have low technical requirements, requiring no special technical training.
[0049] Further optimization includes the installation of a temperature detection device in the energy storage tank 10. The condensing turbine exhaust steam recovery system also includes a controller, which is the existing DCS controller from the original exhaust steam recovery system. The signal input terminal of the DCS controller is electrically connected to the temperature detection device, and the signal output terminal is electrically connected to the second circulation pump 92. The DCS controller controls the start and stop of the second circulation pump 92 based on the temperature of the hot water in the energy storage tank 10. Simultaneously, the energy storage tank 10 is equipped with a pressure detection device to measure the pressure within it.
[0050] Example 2 Please refer to Figure 2 This embodiment 2 provides a condensing steam turbine exhaust steam recovery system, which has the same structure and principle as the above embodiment 1, except that: Based on the above embodiment 1, the exhaust steam recovery unit also includes a second steam booster 22 and a second steam booster condenser 32; the steam inlet of the second steam booster 22 is connected to the three-section extraction steam pipeline of the high-pressure cylinder 11 of the No. 2 steam turbine 102 and the exhaust steam outlet pipeline of the low-pressure cylinder of the No. 2 steam turbine 102, respectively, and the second steam booster condenser 32 is connected to the exhaust port of the second steam booster 22.
[0051] In extreme winter temperature conditions, when users require heating temperatures above 90℃, four-stage heating is provided by the high back pressure exhaust steam condenser 6, the first booster turbine condenser 31, the second booster turbine condenser 32, and the heating network heater 7.
[0052] During the fourth-stage heating process, the return water from the heating network in the return water pipeline sequentially enters the high back-pressure exhaust steam condenser 6, the first turbocharger condenser 31 or the second turbocharger condenser 32, the second turbocharger condenser 32 or the first turbocharger condenser 31, and the heating network heater 7 for fourth-stage heating, and then is transported through the heating network supply water pipeline. The order in which the return water enters the first turbocharger condenser 31 and the second turbocharger condenser 32 can be interchanged. The path of the working steam described below is based on the return water sequentially entering the high back-pressure exhaust steam condenser 6, the first turbocharger condenser 31, the second turbocharger condenser 32, and the heating network heater 7.
[0053] The low-grade exhaust steam discharged from the low-pressure cylinder 12 of turbine 101 is first collected in the exhaust steam device 4, and then enters the high back-pressure exhaust steam condenser 6 to exchange heat with the return water of the heating network, completing the first stage of heating of the return water to above 70.5°C. The low-grade exhaust steam enters the first turbine 21 and mixes with the high-grade steam from the high-pressure cylinder 11 of turbine 101, which also enters the first turbine 21, to form medium-grade steam. The medium-grade steam then enters the first turbine condenser 31 to exchange heat with the return water of the heating network, completing the second stage of heating of the return water to above 80.5°C.
[0054] The low-grade exhaust steam discharged from the low-pressure cylinder of the No. 2 steam turbine 102 first enters the second steam booster 22, where it mixes with the high-grade steam entering the second steam booster 22 from the high-pressure cylinder of the No. 2 steam turbine 102 to form medium-grade steam. Then, the medium-grade steam enters the condenser 32 of the second steam booster to exchange heat with the return water of the heating network, completing the three-stage heating of the return water of the heating network, raising the temperature of the return water of the heating network to above 90°C.
[0055] The high-grade steam extracted from the high-pressure cylinder 11 of the No. 1 steam turbine 101 directly enters the heating network heater 7 and exchanges heat with the heating network return water to complete the four-stage heating of the heating network return water. The heating network return water can be heated to above 130°C and then supplied to users for heating through the heating network water supply pipeline.
[0056] The above-mentioned four-stage heating can increase the heating temperature of the heating network water supply pipeline while further making full use of the exhaust steam heat energy.
[0057] The preferred embodiments of the present invention are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A condensing steam turbine exhaust steam recovery system characterized by: This includes waste steam recovery units, as well as heating network supply units and peak shaving units for non-heating seasons; The waste steam recovery unit is connected to the working steam outlet pipe of the steam turbine. The off-heating season peak shaving unit is arranged in parallel with the heating network heating unit; the off-heating season peak shaving unit or the heating network heating unit exchanges heat with the waste steam recovery unit respectively.
2. A condensing steam turbine exhaust steam recovery system in accordance with claim 1 wherein, The non-heating season peak shaving unit includes an energy storage heat exchange pipeline, an energy storage water inlet pipeline, an energy storage water tank (10), and an energy storage return water pipeline; The energy storage heat exchange pipeline exchanges heat with the waste steam recovery unit; One end of the energy storage water inlet pipe is connected to the outlet of the energy storage heat exchange pipe, and the other end of the energy storage water inlet pipe is connected to the hot water inlet of the energy storage water tank (10). One end of the energy storage return water pipe is connected to the cold water outlet of the energy storage water tank (10), and the other end of the energy storage return water pipe is connected to the inlet of the energy storage heat exchange pipe. A second circulation pump (92) is installed on the energy storage return water pipe.
3. The condensing steam turbine exhaust steam recovery system according to claim 2, characterized in that, The non-heating season peak shaving unit also includes a domestic hot water pipeline, a domestic hot water station heat exchanger (13), and a water return pipeline connected in series. The heat exchanger (13) of the domestic hot water station is connected to the hot water outlet of the energy storage tank (10) through the domestic hot water pipeline, and the heat exchanger (13) of the domestic hot water station is connected to the cold water return outlet of the energy storage tank (10) through the water return pipeline. The factory's domestic water pipes exchange heat with the hot water in the heat exchanger (13) of the domestic hot water station.
4. A condensing steam turbine exhaust steam recovery system according to claim 2, characterized in that, The energy storage tank (10) is equipped with a temperature detection device.
5. A condensing steam turbine exhaust steam recovery system according to claim 4, characterized in that, The condensing steam turbine exhaust steam recovery system also includes a controller, the signal input terminal of which is electrically connected to a temperature detection device, and the signal output terminal of which is electrically connected to a second circulating pump (92).
6. A condensing steam turbine exhaust steam recovery system according to claim 2, characterized in that, The energy storage tank (10) is equipped with a pressure detection device.
7. A condensing steam turbine exhaust steam recovery system according to claim 2, characterized in that, The energy storage tank (10) is an atmospheric pressure heat storage tank or a pressurized heat storage tank.
8. A condensing steam turbine exhaust steam recovery system according to any one of claims 1-7, characterized in that, The waste steam recovery unit includes a first steam turbine (21), a first steam turbine condenser (31), a high back pressure waste steam condenser (6), and a heat network heater (7). The steam inlet of the first steam generator (21) is connected to the extraction steam pipe of the high-pressure cylinder (11) of the No. 1 steam turbine (101). At the same time, the steam inlet of the first steam generator (21) is also connected to the exhaust steam outlet pipe of the low-pressure cylinder (12) of the No. 1 steam turbine (101). The steam inlet of the first steam turbine condenser (31) is connected to the steam outlet of the first steam turbine (21); The inlet of the high back pressure exhaust steam condenser (6) is connected to the exhaust steam outlet pipe of the low pressure cylinder (12) of the No. 1 steam turbine (101); The steam inlet of the heat network heater (7) is connected to the extraction steam pipe of the high-pressure cylinder (11) of the No. 1 steam turbine (101); The heating network heating unit includes a heating network water supply pipeline and a heating network return water pipeline. The heating network return water in the heating network return water pipeline enters the high back pressure exhaust steam condenser (6), the first steam turbine condenser (31) and the heating network heater (7) in sequence for three-stage heating, and then is transported through the heating network water supply pipeline.
9. A condensing steam turbine exhaust steam recovery system according to claim 8, characterized in that, The waste steam recovery unit also includes a second steam turbine (22) and a second steam turbine condenser (32); The steam inlet of the second steam generator (22) is connected to the high-pressure cylinder extraction pipe of the No. 2 steam turbine (102). At the same time, the steam inlet of the second steam generator (22) is also connected to the low-pressure cylinder exhaust steam outlet pipe of the No. 2 steam turbine (102). The second steam turbine condenser (32) is connected to the exhaust port of the second steam turbine (22); The return water from the heat network in the heat network return water pipeline enters the high back pressure exhaust steam condenser (6), the first steam turbine condenser (31) or the second steam turbine condenser (32) in sequence, the second steam turbine condenser (32) or the first steam turbine condenser (31), and the heat network heater (7) for four-stage heating, and then is transported through the heat network water supply pipeline.
10. A condensing steam turbine exhaust steam recovery system according to claim 1, characterized in that, The non-heating season peak shaving unit also includes an air condenser (5), which is connected to the exhaust steam outlet pipe of the low-pressure cylinder of the steam turbine.