Flexible large-scale high-parameter heat supply system of thermal power plant

Abstract

The invention discloses a flexible large-scale high-parameter heat supply system for a thermal power plant. The flexible large-scale high-parameter heat supply system comprises a thermal generator set, an industrial heat supply mother pipe, a water supply device, a high-low pressure steam combined heat exchange device and a condensate water collecting device. The high-low pressure steam combined heat exchange device is connected with the conveying pipeline through a hot air input pipeline, and is connected with the water supply port through a water input pipeline; vent steam input into the high-low pressure steam combined heat exchange device from the hot gas input pipeline is used for heating water input into the high-low pressure steam combined heat exchange device from the water input pipeline to form reheated steam, and then the reheated steam is conveyed to the industrial heat supply mother pipe. According to the flexible large-scale high-parameter heat supply system of the thermal power plant, the quality of steam in the industrial heat supply main pipe can be adjusted more flexibly.

Description

Technical Field

[0001] The invention relates to the technical field of thermal power generation, and in particular to a flexible, large-scale, high-parameter heating system for a thermal power plant. Background Art

[0002] With the continuous development and maturity of the power ancillary service market and the establishment of the power spot market, the flexibility transformation technology of thermal power plants to adapt to the operation of the power market will usher in development opportunities.

[0003] For heating units, since the heating load is generally large in winter, a certain boiler output needs to be maintained, and the problem of low-load operation of the boiler is less involved. The main contradiction is that the adjustment range of power generation output to meet heating conditions is too small, that is, the problem of thermal-electric decoupling. How to reduce steam work while meeting heating conditions, that is, the redistribution of the work share and heating share of high-temperature and high-pressure steam in the turbine is the key to solving the problem.

[0004] Although traditional technologies can solve the problems of heating and load reduction to a certain extent, they are limited to providing low-parameter steam and cannot meet the needs of large-scale high-parameter heating. This limits the ability of thermal power plants to flexibly respond to changes in market demand and also restricts their potential in energy conservation and emission reduction. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to propose a flexible large-scale high-parameter heating system for a thermal power plant, by using the exhausted steam input from the hot gas input pipeline into the high-low pressure steam combined heat exchange device to heat the water input from the water input pipeline into the high-low pressure steam combined heat exchange device to form reheated steam, and then outputting the reheated steam to the industrial heating main pipe, the energy in the steam exhaust gas generated by the thermal power generating unit can be more fully utilized to reduce energy loss; and the quality of the steam in the industrial heating main pipe can be more flexibly adjusted, the thermal power generating unit can maintain wide load flexibility operation while providing large-scale heating, and avoid the quality of the steam in the industrial heating main pipe being completely affected by the output efficiency of the thermal power generating unit, and can meet different requirements for the quality of the steam in the industrial heating main pipe.

[0006] According to an embodiment of the present invention, a flexible, large-scale, high-parameter heating system for a thermal power plant comprises: a thermal power generating set, wherein the thermal power generating set has a waste steam output port, the steam discharged from the waste steam output port is waste steam, the waste steam output port is connected to a delivery pipeline, and the delivery pipeline is provided with a first delivery fan; an industrial heating main pipe, the industrial heating main pipe is connected to the delivery pipeline through a waste steam output pipeline, and the waste steam output pipeline is used to transport the waste steam discharged from the waste steam output port to the industrial heating main pipe; a water supply device, the water supply device has a water supply port; a high- and low-pressure steam combined heat exchange device, the high- and low-pressure steam combined heat exchange device is connected to the delivery pipeline through a hot gas input pipeline, and the hot gas input pipeline is used to transport the waste steam discharged from the waste steam output port to the high- and low-pressure steam combined heat exchange device, the high- and low-pressure steam combined heat exchange device is connected to the water supply port through a water input pipeline, the water input pipeline is provided with an input pump, and the water input pipeline is used to transport the water discharged from the water supply port to In the high- and low-pressure steam combined heat exchange device, the exhausted steam input from the hot gas input pipeline into the high- and low-pressure steam combined heat exchange device is used to heat the water input from the water input pipeline into the high- and low-pressure steam combined heat exchange device to form reheated steam, the high- and low-pressure steam combined heat exchange device is connected to the industrial heating main pipe through a reheated steam output pipeline, and the reheated steam output pipeline is used to transport the reheated steam formed in the high- and low-pressure steam combined heat exchange device to the industrial heating main pipe; a condensate collecting device, the condensate collecting device and the high- and low-pressure steam combined heat exchange device are connected through a condensate recovery pipeline, the condensate collecting device and the water supply device are connected through a water circulation pipeline, the water circulation pipeline is provided with a circulating pump body, the condensate recovery pipeline is used to transport the condensed water formed after the exhausted steam in the high- and low-pressure steam combined heat exchange device to the condensate collecting device, and the water circulation pipeline is used to transport the condensed water in the condensate collecting device to the water supply device.

[0007] According to the flexible large-scale high-parameter heating system for a thermal power plant according to an embodiment of the present invention, by making the exhausted steam input from the hot gas input pipeline into the high- and low-pressure steam combined heat exchange device be used to heat the water input from the water input pipeline into the high- and low-pressure steam combined heat exchange device to form reheated steam, and then outputting the reheated steam to the industrial heating main pipe, the energy in the steam exhaust gas generated by the thermal power generating units can be more fully utilized to reduce energy losses; moreover, the quality of the steam in the industrial heating main pipe can be more flexibly adjusted, and the thermal power generating units can maintain wide load flexibility operation while providing large-scale heating, thereby avoiding the quality of the steam in the industrial heating main pipe being completely affected by the output efficiency of the thermal power generating units, and being able to meet different requirements for the quality of the steam in the industrial heating main pipe.

[0008] According to some embodiments of the present invention, the high- and low-pressure steam combined heat exchange device includes a heat exchange box, a preheating heater, a phase change heater and a superheating heater, the preheating heater, the phase change heater and the superheating heater are all arranged in the heat exchange box, the hot gas input pipeline is connected to the heat exchange box and is suitable for conveying the exhausted steam into the heat exchange box, the exhausted steam input into the heat exchange box is used to heat the preheating heater, the phase change heater and the superheating heater, the preheating heater has a first preheating inlet and a first preheating outlet, the phase change heater has a phase change inlet and a phase change outlet, the superheater has a first superheating inlet and a superheating outlet, the water input pipeline is connected to the first preheating inlet, the first preheating outlet is connected to the phase change inlet through a first connecting pipeline, the phase change outlet is connected to the first superheating inlet through a second connecting pipeline, and the superheating outlet is connected to the inlet end of the reheat steam output pipeline.

[0009] According to some embodiments of the present invention, the high- and low-pressure steam combined heat exchange device also includes a reheat heater, which is arranged in the heat exchange box, and has a reheat inlet and a reheat outlet. The preheat heater also has a second preheat inlet and a second preheat outlet, and the superheat heater also has a second superheat inlet. The reheat inlet is connected to the outlet end of the reheat steam output pipe through a third connecting pipe, the reheat outlet is connected to the second preheat inlet through a fourth connecting pipe, and the second preheat outlet is connected to the second superheat inlet through a fifth connecting pipe.

[0010] According to some embodiments of the present invention, the fifth connecting pipeline is provided with a first control valve, and the first control valve is used to control the opening and closing of the fifth connecting pipeline.

[0011] According to some embodiments of the present invention, it also includes an electrically controlled three-way valve, which has a first connection port, a second connection port and a third connection port. The first connection port is connected to the industrial heating main pipe, the second connection port is connected to the outlet end of the reheat steam output pipeline, and the third connection port is connected to the third connecting pipeline.

[0012] According to some embodiments of the present invention, the condensate collecting device is located below the heat exchange box; and / or the condensate recovery pipe is provided with a second control valve, and the second control valve is used to control the opening and closing of the condensate recovery pipe.

[0013] According to some embodiments of the present invention, the hot gas input pipeline is provided with a third control valve, and the third control valve is used to control the on-off of the hot gas input pipeline. The spent steam output pipeline is provided with a fourth control valve, and the fourth control valve is used to control the on-off of the spent steam output pipeline.

[0014] According to some embodiments of the present invention, the flow area of ​​the third control valve is adjustable; and / or the flow area of ​​the fourth control valve is adjustable.

[0015] According to some embodiments of the present invention, the reheat steam output pipeline is provided with a second transport fan; and / or the water input pipeline is provided with a fifth control valve, and the fifth control valve is used to control the on-off of the water input pipeline.

[0016] According to some embodiments of the present invention, the industrial heating main pipe is provided with a third transport fan and a fifth control valve, and the third control valve is used to control the on-off of the industrial heating main pipe; and / or, a sixth connecting pipe is connected between the industrial heating main pipe (20) and the steam turbine, and the sixth connecting pipe is used to transport the steam in the industrial heating main pipe (20) to the steam turbine, and the sixth connecting pipe is provided with a sixth control valve for controlling the on-off of the sixth connecting pipe.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 Schematic diagram of a flexible large-scale high-parameter heating system for a thermal power plant according to some embodiments of the present invention.

[0020] Reference numerals:

[0021] 100. Flexible large-scale high-parameter heating system for thermal power plants;

[0022] 10. Thermal power generating unit; 11. Exhaust steam output port; 12. Third control valve; 13. Transport pipeline; 14. First transport fan;

[0023] 20. Industrial heating main pipe; 21. Exhaust steam output pipeline; 22. Fourth control valve; 23. Reheat steam output pipeline; 24. Second conveying fan; 25. Third conveying fan; 26. Fifth control valve; 27. Sixth connecting pipeline; 28. Sixth control valve;

[0024] 30. High- and low-pressure steam combined heat exchange device; 31. Hot gas input pipeline; 32. Heat exchange box; 33. Preheating heater; 34. First preheating inlet; 35. First preheating outlet; 36. First connecting pipeline; 37. Second preheating inlet; 38. Second preheating outlet; 39. Fourth connecting pipeline; 40. Phase change heater; 41. Phase change inlet; 42. Phase change outlet; 43. Second connecting pipeline; 44. Superheating heater; 45. First superheating inlet; 46. Superheating outlet; 47. Second superheating inlet; 48. Fifth connecting pipeline; 49. First control valve; 50. Reheating heater; 51. Reheating inlet; 52. Reheating outlet; 53. Third connecting pipeline;

[0025] 60. water supply device; 61. water supply port; 62. water input pipeline; 63. fifth control valve; 64. input pump;

[0026] 65. Condensate collection device; 66. Condensate recovery pipeline; 67. Second control valve; 68. Water circulation pipeline;

[0027] 69. Circulation pump body;

[0028] 70. Electric-controlled three-way valve; 71. First connection port; 72. Second connection port; 73. Third connection port. DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0030] Reference below Figure 1 A flexible large-scale high-parameter heating system 100 for a thermal power plant according to an embodiment of the present invention is described.

[0031] According to an embodiment of the present invention, a flexible, large-scale, high-parameter heating system 100 for a thermal power plant includes: a thermal power generating set 10, an industrial heating main pipe 20, a water supply device 60, a high- and low-pressure steam combined heat exchange device 30, and a condensate collection device 65.

[0032] The thermal power generating unit 10 has an exhaust steam outlet 11, and the steam discharged from the exhaust steam outlet 11 is exhaust steam. The exhaust steam outlet 11 is connected to a delivery pipeline 13, and the delivery pipeline 13 is provided with a first delivery fan 14. By providing the first delivery fan 14 in the delivery pipeline 13, the first delivery fan 14 can drive the exhaust steam to move in the loose pipeline in a direction away from the exhaust steam outlet 11, so as to smoothly discharge the exhaust steam and facilitate the subsequent utilization of the energy in the exhaust steam.

[0033] The industrial heating mother pipe 20 is connected to the delivery pipeline 13 through the exhaust steam output pipe 21, and the exhaust steam output pipe 21 is used to transport the exhaust steam discharged from the exhaust steam output port 11 to the industrial heating mother pipe 20. For example, the industrial heating mother pipe 20 can be connected to industrial heat-demanding equipment to provide high-temperature steam for thermal power generation, user heating, etc. By connecting the industrial heating mother pipe 20 and the delivery pipeline 13 through the exhaust steam output pipe 21, the exhaust steam can flow into the industrial heating mother pipe 20 through the exhaust steam output pipe 21, and the energy in the steam exhaust gas generated by the thermal power generation unit 10 can be more fully utilized to reduce energy loss.

[0034] The water supply device 60 has a water supply port 61. The high-low pressure steam combined heat exchange device 30 is connected to the delivery pipeline 13 through a hot gas input pipeline 31, and the hot gas input pipeline 31 is used to transport the exhaust steam discharged from the exhaust steam output port 11 to the high-low pressure steam combined heat exchange device 30. The high-low pressure steam combined heat exchange device 30 is connected to the water supply port 61 through a water input pipeline 62, and the water input pipeline 62 is provided with an input pump 64. The water input pipeline 62 is used to transport the water discharged from the water supply port 61 to the high-low pressure steam combined heat exchange device 30. The exhaust steam input from the hot gas input pipeline 31 to the high-low pressure steam combined heat exchange device 30 is used to heat the water input from the water input pipeline 62 to the high-low pressure steam combined heat exchange device 30 to form reheat steam. The high-low pressure steam combined heat exchange device 30 is connected to the industrial heating main pipe 20 through the reheat steam output pipeline 23, and the reheat steam output pipeline 23 is used to transport the reheat steam formed in the high-low pressure steam combined heat exchange device 30 to the industrial heating main pipe 20. By using the exhausted steam input from the hot gas input pipeline 31 into the high-low pressure steam combined heat exchange device 30 to heat the water input from the water input pipeline 62 into the high-low pressure steam combined heat exchange device 30 to form reheat steam, and then outputting the reheat steam to the industrial heating main pipe 20, the quality of the steam in the industrial heating main pipe 20 can be more flexibly adjusted, and the effective decoupling of the boiler and the steam turbine of the thermal power generator set 10 is achieved. The thermal power generator set 10 maintains wide load flexibility operation while providing large-scale heat, avoiding the quality of the steam in the industrial heating main pipe 20 being completely affected by the output efficiency of the thermal power generator set 10, and can meet different requirements for the quality of the steam in the industrial heating main pipe 20. Among them, the quality of steam can include superheat, pressure, temperature, etc.

[0035] For example, the exhaust steam input from the hot gas input pipeline 31 into the high- and low-pressure steam combined heat exchange device 30 can be used to heat the water input from the water input pipeline 62 into the high- and low-pressure steam combined heat exchange device 30 to form reheated steam, and then the reheated steam is output to the industrial heating main pipe 20; and, part of the exhaust steam discharged from the exhaust steam output port 11 is transported to the industrial heating main pipe 20 through the exhaust steam output pipeline 21, so that the higher temperature exhaust steam is mixed with the reheated steam. This not only improves the quality of the reheated steam, but also ensures that the quality of the steam is not completely affected by the working efficiency of the thermal power generator set 10, thereby better meeting relevant needs.

[0036] The condensate collection device 65 is connected to the high-low pressure steam combined heat exchange device 30 via a condensate recovery pipe 66, and the condensate collection device 65 is connected to the water supply device 60 via a water circulation pipe 68. The water circulation pipe 68 is provided with a circulation pump body 69. The condensate recovery pipe 66 is used to transport the condensate formed by condensing the exhaust steam in the high-low pressure steam combined heat exchange device 30 to the condensate collection device 65. The water circulation pipe 68 is used to transport the condensate in the condensate collection device 65 to the water supply device 60. By making the large-scale high-parameter heating system 100 of the thermal power plant flexible include the condensate collection device 65, the condensate formed by condensing the exhaust steam can be recycled and reused, avoiding water waste and saving resources. By providing the water circulation pipe 68 with a circulation pump body 69, the water in the condensate collection device 65 can be driven to flow to the water supply device 60 for reuse.

[0037] The system makes full use of the heat in the steam tail gas of the thermal power generating unit 10 through the combined application of exhaust steam and reheated steam, realizes effective heating of the supply water, significantly improves the heating efficiency, and the pressure of the heating steam can be flexibly adjusted within the subcritical range, while the steam supply temperature can be close to the rated temperature of the exhaust steam, thus breaking through the limitation of the reheated steam pressure in the traditional heating system. In this way, not only the problems existing in the traditional heating system are solved, but also the heating capacity and efficiency of the thermal power plant are greatly improved, the effective decoupling of the boiler and the steam turbine is realized, and the thermal power generating unit 10 is supported to maintain wide load flexibility operation while providing large-scale heating.

[0038] The large-scale, high-parameter heating system 100 for thermal power plants can achieve large-scale, high-parameter heating on the basis of ensuring the safe operation of boilers and steam turbines. First, the pressure of the heating steam can be flexibly adjusted within the subcritical range, and the steam supply temperature can be close to the rated temperature of the spent steam, thus breaking through the limitation of the reheat steam pressure in the traditional heating system. Secondly, the system significantly improves the heating efficiency and reduces unnecessary energy losses by rationally allocating the use of high-pressure main steam and high-temperature reheat steam. Since the heating capacity is no longer limited by the power generation capacity of the steam turbine, the thermal power generating unit 10 can respond to market changes more flexibly, improving the economy and environmental friendliness of the overall operation.

[0039] According to the flexible large-scale high-parameter heating system 100 for a thermal power plant in an embodiment of the present invention, by using the exhausted steam input from the hot gas input pipeline 31 into the high- and low-pressure steam combined heat exchange device 30 to heat the water input from the water input pipeline 62 into the high- and low-pressure steam combined heat exchange device 30 to form reheated steam, and then outputting the reheated steam to the industrial heating main pipe 20, the energy in the steam exhaust gas generated by the thermal power generating set 10 can be more fully utilized to reduce energy loss; moreover, the quality of the steam in the industrial heating main pipe 20 can be more flexibly adjusted, and the thermal power generating set 10 maintains wide load flexibility operation while providing large-scale heating, thereby avoiding the quality of the steam in the industrial heating main pipe 20 being completely affected by the output efficiency of the thermal power generating set 10, and being able to meet different requirements for the quality of the steam in the industrial heating main pipe 20.

[0040] According to some embodiments of the present invention, referring to Figure 1 The high- and low-pressure steam combined heat exchange device 30 includes a heat exchange box 32, a preheating heater 33, a phase change heater 40 and a superheating heater 44. The preheating heater 33, the phase change heater 40 and the superheating heater 44 are all arranged in the heat exchange box 32. The hot gas input pipeline 31 is connected to the heat exchange box 32 and is suitable for conveying exhaust steam into the heat exchange box 32. The exhaust steam input into the heat exchange box 32 is used to heat the preheating heater 33, the phase change heater 40 and the superheating heater 44. The preheating heater 33 has There is a first preheating inlet 34 and a first preheating outlet 35, the phase change heater 40 has a phase change inlet 41 and a phase change outlet 42, the superheat heater 44 has a first superheating inlet 45 and a superheating outlet 46, the water input pipe 62 is connected to the first preheating inlet 34, the first preheating outlet 35 is connected to the phase change inlet 41 through the first connecting pipe 36, the phase change outlet 42 is connected to the first superheating inlet 45 through the second connecting pipe 43, and the superheating outlet 46 is connected to the inlet end of the reheat steam output pipe 23. These components work together to ensure that the heating water can be efficiently converted into heating steam that meets the requirements.

[0041] For example, when the flexible large-scale high-parameter heating system 100 of a thermal power plant is in operation, the exhaust steam leaves the thermal power generator set 10 from the hot gas delivery port, and enters the delivery pipeline 13 driven by the first delivery fan 14, and a part of the exhaust steam enters the high and low pressure steam combined heat exchange device 30 through the hot gas input pipeline 31, and the exhaust steam exchanges heat with water. The condensed water formed after the exhaust steam releases heat enters the condensed water collection device 65 through the condensed water recovery pipeline 66, and enters the water supply device 60 through the water circulation pipeline 68 driven by the circulation pump body 69; another part of the exhaust steam directly enters the industrial heating main pipe 20 through the exhaust steam output pipeline 21. After the water leaves the water supply device 60 from the water supply port 61, it is driven by the input pump 64 to enter the water input pipe 62, and then enters the preheating heat exchanger to exchange heat with the exhaust steam. The heated water leaves the preheating heat exchanger from the first preheating outlet 35 and enters the phase change heat exchanger through the first connecting pipe 36. The water exchanges heat with the exhaust steam and undergoes a phase change to become water vapor. The water vapor enters the superheating heat exchanger through the second connecting pipe 43 to continue to exchange heat with the exhaust steam, further increasing the temperature of the water vapor. Finally, it enters the industrial heating main pipe 20 through the reheat steam output pipe, and is mixed with part of the exhaust steam introduced into the industrial heating main pipe 20 to be supplied for industrial heating.

[0042] According to some embodiments of the present invention, referring to Figure 1 The high- and low-pressure steam combined heat exchange device 30 also includes a reheat heater 50, which is arranged in the heat exchange box 32. The reheat heater 50 has a reheat inlet 51 and a reheat outlet 52. The preheat heater 33 also has a second preheat inlet 37 and a second preheat outlet 38. The superheat heater 44 also has a second superheat inlet 47. The reheat inlet 51 is connected to the outlet end of the reheat steam output pipeline 23 through a third connecting pipeline 53, the reheat outlet 52 is connected to the second preheat inlet 37 through a fourth connecting pipeline 39, and the second preheat outlet 38 is connected to the second superheat inlet 47 through a fifth connecting pipeline 48. By making the high-low pressure steam combined heat exchange device 30 also include a reheat heater 50, and connecting the reheat inlet 51 with the outlet end of the reheat steam output pipe 23 through the third connecting pipe 53, the water vapor heated by the high-low pressure steam combined heat exchange device 30 can enter the reheat heater 50 through the reheat steam output pipe 23 and the third connecting pipe for secondary heating, further increasing the temperature of the water vapor, and when the relevant industry has high requirements for the steam quality in the industrial heating mother pipe 20, the corresponding needs can be better met. Since the water vapor entering the high-low pressure steam combined heat exchange device 30 for the second time does not need to undergo a phase change from water to steam, by connecting the second preheating outlet 38 with the second superheating inlet 47 through the fifth connecting pipe 48, the water vapor entering the preheating heat exchanger can directly enter the superheating heat exchanger through the fifth connecting pipe, skipping the phase change heat exchanger, and increasing the production rate.

[0043] For example, the first preheating outlet 35 is located at the lower part of the preheating heat exchanger, and the second preheating outlet 38 is located at the upper part of the preheating heat exchanger. The preheating heat exchanger contains water that initially enters the high- and low-pressure steam combined heat exchanger 30 and water vapor that enters the high- and low-pressure steam combined heat exchanger 30 again. The water is located at the lower part of the preheating heat exchanger and can leave the preheating heat exchanger through the first preheating outlet 35. The water vapor is located at the upper part of the preheating heat exchanger and can leave the preheating heat exchanger through the second preheating outlet 38. The water that first enters the high- and low-pressure steam combined heat exchanger 30 and the water vapor that enters the high- and low-pressure steam combined heat exchanger 30 again are separated by the difference between the gas and liquid phases, and are guided to continue to flow to different heat exchangers.

[0044] For example, when the relevant industry has higher requirements on the steam quality in the industrial heating main pipe 20, the water can leave the water supply device 60 from the water supply port 61, and then be driven by the input pump 64 to enter the water input pipe 62, and then enter the preheating heat exchanger to exchange heat with the exhausted steam. The heated water leaves the preheating heat exchanger from the first preheating outlet 35 and enters the phase change heat exchanger through the first connecting pipe 36. The water exchanges heat with the exhausted steam and undergoes a phase change to become water vapor. The water vapor enters the superheating heat exchanger through the second connecting pipe 43 to continue to exchange heat with the exhausted steam, enters the third connecting pipe 53 through the reheat steam output pipe, and once again enters the high and low pressure steam combined heat exchange device 30, enters the reheating heat exchanger for further heat exchange, and then enters the preheating heat exchanger through the fourth connecting pipe 39. At this time, the preheating heat exchanger contains condensed water that initially enters the high- and low-pressure steam combined heat exchange device 30 and water vapor that enters the high- and low-pressure steam combined heat exchange device 30 again. The water leaves the preheating heat exchanger through the first connecting pipe 36, and the water vapor enters the superheating heat exchanger through the fifth connecting pipe 48 and continues to exchange heat, and then leaves the high- and low-pressure steam combined heat exchange device 30 through the reheat steam output pipe and enters the industrial heating main pipe 20. This part of the water vapor is mixed with the exhaust steam and passed into the industrial heating main pipe 20 to provide heat.

[0045] According to some embodiments of the present invention, referring to Figure 1 The fifth connecting pipe 48 is provided with a first control valve 49, and the first control valve 49 is used to control the opening and closing of the fifth connecting pipe 48. By providing the fifth connecting pipe 48 with the first control valve 49, the fifth connecting pipe 48 can be opened and closed according to demand, so that the water vapor in the preheating heat exchanger can select a path according to the opening and closing of the fifth connecting pipe, change the heat exchange time of this part of the water vapor, and adjust the temperature of the water vapor in the industrial heating mother pipe 20 in a wider range.

[0046] For example, when the relevant industry has high requirements for the steam quality in the industrial heating main pipe 20, the first control valve 49 can be opened to make the fifth connecting pipe 48 unobstructed. The water vapor in the preheating heat exchanger that enters the high- and low-pressure steam combined heat exchange device 30 for the second time enters the superheating heat exchanger through the fifth connecting pipe 48 and continues to exchange heat, and then leaves the high- and low-pressure steam combined heat exchange device 30 through the reheat steam output pipe and enters the industrial heating main pipe 20. This part of the water vapor is mixed with the exhaust steam and passed into the industrial heating main pipe 20 to provide heat.

[0047] For example, when the relevant industry further improves the requirements for the steam quality in the industrial heating main pipe 20, the first control valve 49 can be closed to disconnect the fifth connecting pipe 48. The water vapor in the preheating heat exchanger that enters the high- and low-pressure steam combined heat exchanger 30 for the second time enters the phase change heat exchanger through the first connecting pipe 36, increasing the flow time of the water vapor in the high- and low-pressure steam combined heat exchanger 30 to increase the temperature of the water vapor, and then enters the superheating heat exchanger through the second connecting pipe 43 to continue heat exchange, and then leaves the high- and low-pressure steam combined heat exchanger 30 through the reheat steam output pipe and enters the industrial heating main pipe 20. This part of the water vapor is mixed with the exhaust steam and passed into the industrial heating main pipe 20 to provide heat.

[0048] According to some embodiments of the present invention, referring to Figure 1 The flexible large-scale high-parameter heating system 100 for a thermal power plant further includes an electrically controlled three-way valve 70, which has a first connection port 71, a second connection port 72, and a third connection port 73. The first connection port 71 is connected to the industrial heating main pipe 20, the second connection port 72 is connected to the outlet end of the reheat steam output pipeline 23, and the third connection port 73 is connected to the third connection pipeline 53. The electrically controlled three-way valve 70 can change the switch of the three-way valve through an electrical signal to control the flow path of part of the water vapor in the flexible large-scale high-parameter heating system 100 for a thermal power plant, thereby changing the heating time of the water vapor in the flexible large-scale high-parameter heating system 100 for a thermal power plant according to demand and changing the quality of the steam in the industrial heating main pipe 20. By making the flexible large-scale high-parameter heating system 100 for a thermal power plant further include the electrically controlled three-way valve 70, the quality of the steam in the industrial heating main pipe 20 can be more flexibly adjusted according to demand, so that the range of steam quality in the industrial heating main pipe 20 can be wider.

[0049] For example, when the relevant industry has low requirements on the steam quality in the industrial heating main pipe 20, the electric three-way valve 70 can close the third connecting port 73, and the water is heated in turn by the preheating heat exchanger, the phase change heat exchanger and the superheating heat exchanger to become water vapor. The water vapor is directly led to the industrial heating main pipe 20 through the reheat steam output pipe to provide heat to the relevant industry.

[0050] For example, when the relevant industry has higher requirements on the steam quality in the industrial heating main pipe 20, the electric three-way valve 70 can be opened to open the third connecting port 73, and the water is heated in the preheating heat exchanger, the phase change heat exchanger and the superheating heat exchanger in sequence to become water vapor. The water vapor enters the third connecting pipe 53 through the reheat steam output pipe, and is further heated in the reheat heat exchanger, the preheating heat exchanger and the superheating heat exchanger in sequence, and finally reaches the industrial heating main pipe 20 through the reheat steam output pipe to provide heating to the relevant industries.

[0051] For example, the flexible large-scale high-parameter heating system 100 of a thermal power plant includes an electrically controlled three-way valve 70, and the fifth connecting pipe 48 is provided with a first control valve 49, and the first control valve 49 is used to control the opening and closing of the fifth connecting pipe 48. When the requirements of the relevant industry for the steam quality in the industrial heating mother pipe 20 are further improved, the electrically controlled three-way valve 70 opens the third connecting port 73, and the first control valve 49 is closed, so that the fifth connecting pipe 48 is disconnected. Water is heated in the preheating heat exchanger, the phase change heat exchanger and the superheating heat exchanger in sequence to become water vapor, and the water vapor enters the third connecting pipe 53 through the reheating steam output pipe, and then is further heated in the reheating heat exchanger, the preheating heat exchanger, the phase change heat exchanger and the superheating heat exchanger in sequence, and finally passes through the reheating steam output pipe to the industrial heating mother pipe 20 to provide heat to the relevant industry.

[0052] According to some embodiments of the present invention, referring to Figure 1 The condensed water collecting device 65 is located below the heat exchange box 32. The exhaust steam in the heat exchange box 32 releases heat and eventually liquefies into condensed water and gathers at the bottom of the heat exchange box 32. By locating the condensed water collecting device 65 below the heat exchange box 32, the condensed water gathered at the bottom of the heat exchange box 32 can be recovered more timely, avoiding excessive storage of condensed water in the heat exchange box 32 and affecting the heat exchange process in the high- and low-pressure steam combined heat exchange device 30.

[0053] According to some embodiments of the present invention, referring to Figure 1 The condensed water recovery pipe 66 is provided with a second control valve 67, which is used to control the on-off of the condensed water recovery pipe 66. For example, the second control valve 67 is a one-way valve, so that the condensed water can only flow from the heat exchange box 32 to the condensed water collection device 65, so as to avoid the condensed water backflow.

[0054] According to some embodiments of the present invention, referring to Figure 1, the hot gas input pipeline 31 is provided with a third control valve 12, which is used to control the on and off of the hot gas input pipeline 31, and the exhaust steam output pipeline 21 is provided with a fourth control valve 22, which is used to control the on and off of the exhaust steam output pipeline 21. By providing the hot gas input pipeline 31 with the third control valve 12, the temperature of the steam in the industrial heating mother pipe 20 can be adjusted in a wider range. For example, the third control valve 12 can be opened, and the exhaust steam discharged from the exhaust steam output port 11 can enter the heat exchange box 32 to heat the water, so that the reheated steam can enter the industrial heating mother pipe 20; the third control valve 12 can also be closed, and the exhaust steam directly enters the exhaust steam output pipeline 21 to the industrial heating mother pipe 20 to provide a more sufficient heat source. By providing the exhaust steam output pipeline 21 with the fourth control valve 22, the steam in the industrial heating mother pipe 20 can be mixed with exhaust steam or not mixed with exhaust steam, and the quality of the steam in the industrial heating mother pipe 20 can be adjusted in a wider range, which can better provide heating needs for related industries. For example, the fourth control valve 22 can be opened so that the spent steam can enter the industrial heating main pipe 20 through the spent steam output pipe 21, thereby improving the quality of the steam in the industrial heating main pipe 20; the fourth control valve 22 can also be closed so that the spent steam can only enter the high- and low-pressure steam combined heat exchange device 30 for heat exchange with the supply water, so as to fully meet the requirements of related industries for steam quality.

[0055] According to some embodiments of the present invention, referring to Figure 1 , the flow area of ​​the third control valve 12 is adjustable. By making the flow area of ​​the third control valve 12 adjustable, relevant personnel can adjust the amount of exhaust steam entering the heat exchange box 32 for heating the supply water according to demand, and can more flexibly adjust the quality of steam in the industrial heating main pipe 20 according to demand.

[0056] According to some embodiments of the present invention, the flow area of ​​the fourth control valve 22 is adjustable. By making the flow area of ​​the fourth control valve 22 adjustable, relevant personnel can adjust the amount of spent steam directly introduced into the industrial heating main pipe 20 according to demand, and can more flexibly adjust the quality of steam in the industrial heating main pipe 20 according to demand.

[0057] According to some embodiments of the present invention, the flow areas of the third control valve 12 and the fourth control valve 22 are both adjustable. By making the flow areas of the third control valve 12 and the fourth control valve 22 adjustable, relevant personnel can adjust the ratio between the amount of spent steam directly introduced into the industrial heating main pipe 20 and the amount of spent steam introduced into the heat exchange box 32 for heating the supply water according to demand, and can more flexibly adjust the quality of steam in the industrial heating main pipe 20 according to demand.

[0058] According to some embodiments of the present invention, referring to Figure 1The reheat steam output pipeline 23 is provided with a second delivery fan 24. By providing the reheat steam output pipeline 23 with the second delivery fan 24, the second delivery fan 24 can pressurize the reheat steam in the reheat steam output pipeline 23, further improving the flexibility and heating efficiency of the large-scale high-parameter heating system 100 of the thermal power plant.

[0059] According to some embodiments of the present invention, referring to Figure 1 The water input pipeline 62 is provided with a fifth control valve 63, which is used to control the on-off of the water input pipeline 62. By providing the water input pipeline 62 with the fifth control valve 63, when the large-scale high-parameter flexible heating system 100 of the thermal power plant is shut down or the relevant industrial demand only allows the exhaust steam to enter the industrial heating main pipe 20, the connection between the water supply device 60 and the high- and low-pressure steam combined heat exchange device 30 can be closed to save water and electricity.

[0060] According to some embodiments of the present invention, referring to Figure 1 The industrial heating mother pipe 20 is provided with a third conveying fan 25 and a fifth control valve 26, and the fifth control valve 26 is used to control the on and off of the industrial heating mother pipe 20. By providing the third conveying fan 25 on the industrial heating mother pipe 20, the third conveying fan 25 pressurizes the steam in the industrial heating mother pipe 20, thereby further improving the flexibility and heating efficiency of the large-scale high-parameter heating system 100 of the thermal power plant. For example, the pressure in the industrial heating mother pipe 20 can be flexibly adjusted within the subcritical range, and the temperature can be close to the rated temperature of the exhaust steam, thereby breaking through the limitation of the reheat steam pressure in the heating system of the related technology.

[0061] According to some embodiments of the present invention, referring to Figure 1A sixth connecting pipe 27 is connected between the industrial heating main pipe 20 and the steam turbine. The sixth connecting pipe 27 is used to transport the steam in the industrial heating main pipe 20 to the steam turbine. The sixth connecting pipe 27 is provided with a sixth control valve 28 for controlling the opening and closing of the sixth connecting pipe 27. By connecting the sixth connecting pipe 27 between the industrial heating main pipe 20 and the steam turbine, the steam in the industrial heating main pipe 20 can enter the steam turbine through the sixth connecting pipe 27 to generate electricity again. Through the combined use of high-pressure main steam and high-temperature reheated steam, effective heating of heating water is achieved, and the heated high-pressure main steam condensate and the cooled reheated steam are returned to the boiler system to form a closed cycle, so that the thermal energy in the exhaust steam can be fully utilized and this part of energy can be used to generate electricity again. By providing the sixth connecting pipe 27 with a sixth control valve 28 for controlling the opening and closing of the sixth connecting pipe 27, the sixth control valve 28 can be closed when the industrial heating main pipe 20 needs to be passed into the relevant industry for use, and the sixth control valve 28 can be opened when the industrial heating main pipe 20 needs to be passed into the steam turbine, so as to control the flow direction of the industrial heating main pipe 20 according to demand.

[0062] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0063] In the description of the present invention, "first feature" or "second feature" may include one or more of the features.

[0064] In the description of the present invention, "plurality" means two or more.

[0065] In the description of the present invention, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0066] In the description of the present invention, “on”, “over” and “above” a first feature from a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0067] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0068] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A flexible large-scale high-parameter heating system for a thermal power plant, characterized in that: include: A thermal power generating set, wherein the thermal power generating set comprises a boiler and a steam turbine, wherein the steam turbine has an exhaust steam output port, the steam discharged from the exhaust steam output port is exhaust steam, the exhaust steam output port is connected to a conveying pipeline, and the conveying pipeline is provided with a first conveying fan; An industrial heating main pipe, wherein the industrial heating main pipe is connected to the conveying pipeline via a spent steam output pipeline, and the spent steam output pipeline is used to convey the spent steam discharged from the spent steam output port to the industrial heating main pipe; a water supply device, the water supply device having a water supply port; A high- and low-pressure steam combined heat exchange device, wherein the high- and low-pressure steam combined heat exchange device is connected to the transmission pipeline via a hot gas input pipeline, and the hot gas input pipeline is used to transport the exhausted steam discharged from the exhausted steam output port to the high- and low-pressure steam combined heat exchange device; the high- and low-pressure steam combined heat exchange device is connected to the water supply port via a water input pipeline, and the water input pipeline is provided with an input pump, and the water input pipeline is used to transport the water discharged from the water supply port to the high- and low-pressure steam combined heat exchange device; the exhausted steam input from the hot gas input pipeline into the high- and low-pressure steam combined heat exchange device is used to heat the water input from the water input pipeline into the high- and low-pressure steam combined heat exchange device to form reheated steam; the high- and low-pressure steam combined heat exchange device is connected to the industrial heating main pipe via a reheated steam output pipeline, and the reheated steam output pipeline is used to transport the reheated steam formed in the high- and low-pressure steam combined heat exchange device to the industrial heating main pipe; A condensate collecting device, wherein the condensate collecting device is connected to the high- and low-pressure steam combined heat exchange device via a condensate recovery pipe, and the condensate collecting device is connected to the water supply device via a water circulation pipe, and the water circulation pipe is provided with a circulation pump body. The condensate recovery pipe is used to transport the condensate formed after the exhaust steam in the high- and low-pressure steam combined heat exchange device is condensed to the condensate collecting device, and the water circulation pipe is used to transport the condensate in the condensate collecting device to the water supply device.

2. The flexible large-scale high-parameter heating system for thermal power plants according to claim 1 is characterized in that: The high- and low-pressure steam combined heat exchange device includes a heat exchange box, a preheating heater, a phase change heater and a superheating heater. The preheating heater, the phase change heater and the superheating heater are all arranged in the heat exchange box. The hot gas input pipeline is connected to the heat exchange box and is suitable for conveying the exhausted steam into the heat exchange box. The exhausted steam input into the heat exchange box is used to heat the preheating heater, the phase change heater and the superheating heater. The preheating heater has a first preheating inlet and a first preheating outlet, the phase change heater has a phase change inlet and a phase change outlet, and the superheating heater has a first superheating inlet and a superheating outlet. The water input pipeline is connected to the first preheating inlet, the first preheating outlet is connected to the phase change inlet through a first connecting pipeline, the phase change outlet is connected to the first superheating inlet through a second connecting pipeline, and the superheating outlet is connected to the inlet end of the reheat steam output pipeline.

3. The flexible large-scale high-parameter heating system for thermal power plants according to claim 2 is characterized in that: The high- and low-pressure steam combined heat exchange device also includes a reheat heater, which is arranged in the heat exchange box, and has a reheat inlet and a reheat outlet. The preheat heater also has a second preheat inlet and a second preheat outlet. The superheat heater also has a second superheat inlet. The reheat inlet is connected to the outlet end of the reheat steam output pipeline through a third connecting pipeline, the reheat outlet is connected to the second preheat inlet through a fourth connecting pipeline, and the second preheat outlet is connected to the second superheat inlet through a fifth connecting pipeline.

4. The flexible large-scale high-parameter heating system for thermal power plants according to claim 3 is characterized in that: The fifth connecting pipeline is provided with a first control valve, and the first control valve is used to control the opening and closing of the fifth connecting pipeline.

5. The flexible large-scale high-parameter heating system for thermal power plants according to claim 3 is characterized in that: It also includes an electrically controlled three-way valve, which has a first connection port, a second connection port and a third connection port. The first connection port is connected to the industrial heating main pipe, the second connection port is connected to the outlet end of the reheat steam output pipeline, and the third connection port is connected to the third connecting pipeline.

6. The flexible large-scale high-parameter heating system for thermal power plants according to claim 2 is characterized in that: The condensate collecting device is located below the heat exchange box; and / or the condensate recovery pipeline is provided with a second control valve, and the second control valve is used to control the on-off of the condensate recovery pipeline.

7. The flexible large-scale high-parameter heating system for a thermal power plant according to any one of claims 1 to 6, characterized in that: The hot gas input pipeline is provided with a third control valve, and the third control valve is used to control the on-off of the hot gas input pipeline. The spent steam output pipeline is provided with a fourth control valve, and the fourth control valve is used to control the on-off of the spent steam output pipeline.

8. The flexible large-scale high-parameter heating system for thermal power plants according to claim 7 is characterized in that: The flow area of ​​the third control valve is adjustable; and / or the flow area of ​​the fourth control valve is adjustable.

9. The flexible large-scale high-parameter heating system for a thermal power plant according to any one of claims 1 to 6, characterized in that: The reheat steam output pipeline is provided with a second delivery fan; and / or the water input pipeline is provided with a fifth control valve, and the fifth control valve is used to control the on-off of the water input pipeline.

10. The flexible large-scale high-parameter heating system for a thermal power plant according to any one of claims 1 to 6, characterized in that: The industrial heating main pipe is provided with a third conveying fan and a fifth control valve, and the fifth control valve is used to control the on and off of the industrial heating main pipe; And / or, a sixth connecting pipe is connected between the industrial heating main pipe and the steam turbine, the sixth connecting pipe is used to transport the steam in the industrial heating main pipe to the steam turbine, and the sixth connecting pipe is provided with a sixth control valve for controlling the opening and closing of the sixth connecting pipe.

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