Primary intermediate reheating power generation system coupling ascending pipe waste heat and dry quenching waste heat

Abstract

The utility model belongs to the technical field of coking waste heat utilization, and particularly relates to a primary intermediate reheating power generation system coupling ascension pipe waste heat and dry quenching waste heat, which is characterized in that a low-temperature reheater heat exchanger and a high-temperature reheater heat exchanger are both positioned in a coke oven ascension pipe; the low-temperature reheater heat exchanger is connected with the steam outlet end of a high-pressure cylinder of the steam turbine through a low-temperature reheat steam pipeline, the high-temperature reheater heat exchanger is connected with the steam inlet end of an intermediate-pressure cylinder of the steam turbine through a high-temperature reheat steam pipeline, and the low-temperature reheater heat exchanger and the high-temperature reheater heat exchanger are connected through a desuperheater. And a steam outlet of the dry quenching boiler is connected with a steam inlet end of a high-pressure cylinder of the steam turbine through a superheated steam pipeline. The device has the beneficial effects that the coupling utilization of the waste heat of the dry quenching boiler, the ascension pipe and the waste heat of each link of the steam turbine is realized, and the technical problem that the low-grade low-pressure steam generated by the ascension pipe of the coke oven in the traditional coking industry cannot be further utilized and can only be diffused and wasted is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of coking waste heat utilization, and in particular relates to a primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat. Background Art

[0002] The dry coke quenching device is a special equipment that uses the dry coke quenching boiler to reduce the temperature of the inert circulating gas in the dry coke quenching system, absorbs its heat to generate steam and feeds it into the steam turbine for power generation or heating, and recovers the waste heat of red coke. The temperature of the raw gas in the coke oven riser is about 650-750℃ during normal production, so the heat taken away by the raw gas in the coke oven is very huge, accounting for about 36% of the heat expenditure of the coke oven. Recycling the heat of the raw gas in the coke oven riser can increase the economic benefits of the enterprise, save energy, and increase the company's profits.

[0003] The Chinese utility model patent with application number 202121086769.1 discloses a comprehensive utilization system of waste heat in the coking production process, including a dry coke quenching waste heat recovery system and a raw coal gas waste heat recovery system; the dry coke quenching waste heat recovery system includes a desalted water tank, a steam turbine generator set and a dry coke quenching boiler; the steam turbine generator set includes a high-pressure cylinder, a medium- and low-pressure cylinders and a generator connected in sequence; the dry coke quenching boiler includes a boiler drum, and an economizer, a membrane water cooler and an evaporator, a primary reheater, a secondary reheater, a primary superheater and a secondary superheater arranged in the dry coke quenching boiler body from bottom to top; the raw coal gas waste heat recovery system includes a first riser drum, a first riser heat exchanger, a second riser drum and a second riser heat exchanger; the scheme adopts ultra-high temperature and ultra-high pressure units to generate electricity.

[0004] The Chinese utility model patent with application number 202220109611.X discloses an ultra-high temperature and ultra-high pressure reheating dry quenching waste heat boiler system, including a boiler drum, a deaerator, a steel structure, a water-cooled wall hanging device, a hanging pipe, a high-temperature superheater, a high-temperature reheater, a water-cooled wall, a low-temperature superheater, a low-temperature reheater, a finned tube evaporator, and a high-pressure economizer; the ultra-high temperature and ultra-high pressure reheating generator set generates about 40% more electricity than the medium temperature and medium pressure, and about 15% more electricity than the high temperature and high pressure. The scheme adds a high-temperature reheater and a low-temperature reheater to the structure, and does not have a bare tube evaporator.

[0005] In the prior art, the steam produced by the riser waste heat recovery device is mostly low-grade, low-pressure saturated steam. Some independent coking enterprises not only adopt the coke oven riser waste heat recovery device, but also adopt a number of waste heat utilization measures such as coke oven flue gas waste heat utilization and primary cooler waste hot water refrigeration. As a result, the recovered low-grade steam cannot be used by users, and steam release occurs from time to time, resulting in a waste of resources. Utility Model Content

[0006] The purpose of the utility model is to provide a primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat, overcome the shortcomings of the prior art, can heat up and reheat the low-temperature steam discharged from the high-pressure cylinder of the turbine through a coke oven riser heat exchanger, and then send it to the medium-pressure cylinder of the turbine to do work, couple the dry coke quenching boiler, riser waste heat, and steam turbine links for waste heat utilization, realize high-energy-efficiency recovery and utilization of the waste heat of the raw coal gas in the coke oven riser, and avoid the generation of low-grade low-pressure steam in the coke oven riser in the traditional coking industry.

[0007] To achieve the above purpose, the utility model is implemented through the following technical solutions:

[0008] A primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat comprises a dry coke quenching boiler, a steam turbine, a low-temperature reheater heat exchanger, a desuperheater, a high-temperature reheater heat exchanger, a condenser, a condensate pump, a deaerator and a boiler feed water pump, characterized in that the low-temperature reheater heat exchanger and the high-temperature reheater heat exchanger are both located in the coke oven riser, the low-temperature reheater heat exchanger is connected to the steam outlet end of the high-pressure cylinder of the steam turbine through a low-temperature reheat steam pipeline, and the high-temperature reheater heat exchanger is connected to the steam outlet end of the high-pressure cylinder of the steam turbine through a high-temperature reheat steam pipeline. The hot steam pipeline is connected to the steam inlet end of the intermediate pressure cylinder of the steam turbine, the low-temperature reheater heat exchanger and the high-temperature reheater heat exchanger are connected through a desuperheater, and the steam outlet of the dry coke quenching boiler is connected to the steam inlet end of the high-pressure cylinder of the steam turbine through the superheated steam pipeline; the steam outlet end of the intermediate pressure cylinder of the steam turbine is connected to the condenser, the condensate pump, the deaerator and the boiler feed water pump through pipelines in sequence, and part of the water discharged from the boiler feed water pump is sent to the dry coke quenching boiler to absorb waste heat, and the other part is sent to the desuperheater through the desuperheating water pipeline.

[0009] The superheated steam pressure in the superheated steam pipeline is 3.5-4.2MPa, and the temperature is 420-470°C; the steam pressure in the low-temperature reheated steam pipeline is 0.9-1.0MPa, and the temperature is 280-300°C.

[0010] The desuperheater is a vertical plunger type or a vertical ring spray type desuperheater.

[0011] The low-temperature reheater heat exchanger is a multi-tube header structure.

[0012] The high-temperature reheater heat exchanger is a multi-tube annular header structure.

[0013] The desuperheating water pipeline is provided with a regulating valve.

[0014] The dry quenching boiler is a natural circulation boiler or a forced circulation boiler.

[0015] The steam turbine is a pure condensing steam turbine or an extraction condensing steam turbine.

[0016] The condenser is a double-flow condenser provided with a separation water chamber.

[0017] The deaerator is of low-pressure rotary film type.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1) This system realizes the coupled utilization of waste heat from CDQ boiler, riser and steam turbine. The coke oven riser waste heat utilization system is equipped with coke oven riser low-temperature reheater heat exchanger, water spray desuperheater and coke oven riser high-temperature reheater heat exchanger, which can obtain superheated steam at rated temperature, realize the high-efficiency recovery and utilization of waste heat from raw coal gas in coke oven riser, and avoid the technical problem of low-grade low-pressure steam generated in coke oven riser in traditional coking industry, which cannot be further utilized and can only be released and wasted.

[0020] 2) The system has a compact structure and is easy to implement. It is especially suitable for the transformation and upgrading of conventional CDQ production systems and can save more than 50% of energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a process flow chart of an embodiment of the utility model;

[0022] Figure 2 It is a schematic diagram of the structure of the riser in the embodiment of the utility model.

[0023] In the figure: 1-coke dry quenching boiler, 2-high pressure cylinder of steam turbine, 3-low temperature reheater heat exchanger, 4-desuperheater, 5-high temperature reheater heat exchanger, 6-intermediate pressure cylinder of steam turbine, 7-condenser, 8-condensate pump, 9-deaerator, 10-boiler feed water pump, 11-superheated steam pipeline, 12-low temperature reheat steam pipeline, 13-high temperature reheat steam pipeline, 14-desuperheating water pipeline, 14-inlet annular header, 15-outlet annular header, 16-heat exchange tube bundle, 17-inner wall of riser, 18-outer wall of riser. DETAILED DESCRIPTION

[0024] The technical solution of the present utility model will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.

[0025] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the specific embodiments required to be used in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some implementation methods of the utility model. For ordinary technicians in this field, other specific embodiments can be obtained based on these specific embodiments without paying creative work.

[0026] The components of the embodiments of the present invention generally described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the specific embodiments is not intended to limit the scope of the utility model claimed, but only represents the selected embodiments of the utility model.

[0027] See Figure 1 , 2 , is a process flow diagram of an embodiment of a primary intermediate reheat power generation system coupling riser waste heat and CDQ waste heat of the utility model, including a CDQ boiler 1, a steam turbine, a low-temperature reheater heat exchanger 3, a desuperheater 4, a high-temperature reheater heat exchanger 5, a condenser 7, a condensate pump 8, a deaerator 9 and a boiler 1 feed water pump 10, wherein the low-temperature reheater heat exchanger 3 and the high-temperature reheater heat exchanger 5 are respectively located in different coke oven risers and arranged in groups. A normal coke oven is composed of two groups of coke ovens, the low-temperature reheater heat exchanger 3 is arranged in the riser of group A coke oven, and the high-temperature reheater heat exchanger 5 is arranged in the riser of group B coke oven. The low-temperature reheater heat exchanger 3 is connected to the steam outlet of the high-pressure cylinder 2 of the steam turbine through the low-temperature reheat steam pipeline 12, the high-temperature reheater heat exchanger 5 is connected to the steam inlet of the medium-pressure cylinder 6 of the steam turbine through the high-temperature reheat steam pipeline 13, the low-temperature reheater heat exchanger 3 and the high-temperature reheater heat exchanger 5 are connected through the desuperheater 4, and the steam outlet of the dry coke quenching boiler 1 is connected to the steam inlet of the high-pressure cylinder 2 of the steam turbine through the superheated steam pipeline 11;

[0028] The steam outlet end of the intermediate pressure cylinder 6 of the steam turbine is connected to the condenser 7, the condensate pump 8, the deaerator 9 and the boiler 1 feed water pump 10 in sequence through pipelines. Part of the water discharged from the boiler 1 feed water pump 10 is sent to the dry quenching boiler 1 to absorb waste heat, and the other part is sent to the desuperheater 4 through the desuperheating water pipeline 14, and the cycle is repeated.

[0029] The superheated steam pressure in the superheated steam pipeline 11 is 3.8-4.2 MPa, and the temperature is 420-470° C. The steam pressure in the low-temperature reheated steam pipeline is 0.9-1.0 MPa, and the temperature is 280-300° C. In the embodiment, the desuperheater 4 is any one of a venturi type with a water chamber, a vortex venturi type, or a multi-hole nozzle type water spray desuperheater 4 .

[0030] The structure of the low-temperature reheater heat exchanger 3 is a multi-tube annular header structure. The structure of the high-temperature reheater heat exchanger 5 is also a multi-tube annular header structure, both of which include an inlet annular header 14, an outlet annular header 15, and a heat exchange tube bundle 16 connecting the inlet annular header 14 and the outlet annular header 15. The heat exchange tube bundle 16 is installed between the inner wall 17 of the riser and the outer wall 18 of the riser to exchange heat for the coke oven raw gas between the inner wall 17 of the riser and the outer wall 18 of the riser. A regulating valve is provided on the desuperheating water pipeline 14. The dry quenching coke boiler 1 is a forced circulation boiler.

[0031] The steam turbine is a pure condensing steam turbine. The condenser 7 is a double-flow condenser with a separation water chamber, allowing half to be in operation and the other half to be under maintenance. The deaerator 9 is a low-pressure rotary film type.

[0032] During the operation of the dry coke quenching boiler, the superheated steam of 3.82MPa and 450℃ generated by the dry coke quenching boiler 1 is sent to the high-pressure cylinder 2 of the steam turbine through the hot steam pipeline 11. After the high-pressure cylinder does work, the steam pressure is reduced to 1.0MPa and the temperature is reduced to 300℃. It is discharged into the low-temperature reheat steam pipeline 12, and is sent to the low-temperature reheat heat exchanger 3 in the coke oven riser (the flue gas temperature is 650-750℃) through the low-temperature reheat steam pipeline 12 for heating and reheating (the temperature rises to 380-420℃), and then the temperature is adjusted by the water spray desuperheater 4 (the temperature The steam is sent to the high-temperature reheater heat exchanger 5 for reheating to 450℃, and then sent to the medium-pressure cylinder 6 of the steam turbine through the high-temperature reheat steam pipeline 13 to do work. The steam becomes exhaust steam, which is discharged into the condenser 7 for cooling, and then sent to the deaerator 9 through the condensate pump 8. The boiler feed water after deaeration is pressurized by the boiler feed water pump 10. A part of the water (temperature is 104℃) is sent to the dry quenching boiler 1 to absorb the waste heat, and the other part of the water (temperature is 104℃) is sent to the spray desuperheater 4 through the desuperheating water pipeline 14 to adjust the reheat steam temperature and repeat this cycle. The desuperheating during the working process is to better control the outlet temperature and ensure that the outlet temperature is at the rated temperature of 450℃.

[0033] Although 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 appended claims and their equivalents.

Claims

1. A primary intermediate reheat power generation system coupled with riser waste heat and dry coke quenching waste heat, comprising a dry coke quenching boiler, a steam turbine, a low-temperature reheater heat exchanger, a desuperheater, a high-temperature reheater heat exchanger, a condenser, a condensate pump, a deaerator and a boiler feed pump, characterized in that: The low-temperature reheater heat exchanger and the high-temperature reheater heat exchanger are both located in the coke oven riser, the low-temperature reheater heat exchanger is connected to the steam outlet of the high-pressure cylinder of the steam turbine through a low-temperature reheat steam pipeline, the high-temperature reheater heat exchanger is connected to the steam inlet of the medium-pressure cylinder of the steam turbine through a high-temperature reheat steam pipeline, the low-temperature reheater heat exchanger and the high-temperature reheater heat exchanger are connected through a desuperheater, and the steam outlet of the dry coke quenching boiler is connected to the steam inlet of the high-pressure cylinder of the steam turbine through a superheated steam pipeline; The steam outlet end of the intermediate pressure cylinder of the steam turbine is connected to the condenser, condensate pump, deaerator and boiler feed pump in sequence through pipelines. Part of the water discharged from the boiler feed pump is sent to the dry quenching boiler to absorb waste heat, and the other part is sent to the desuperheater through the desuperheating water pipeline.

2. A primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat according to claim 1, characterized in that: The superheated steam pressure in the superheated steam pipeline is 3.5-4.2MPa, and the temperature is 420-470°C; the steam pressure in the low-temperature reheated steam pipeline is 0.9-1.0MPa, and the temperature is 280-300°C.

3. A primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat according to claim 1, characterized in that: The desuperheater is a vertical plunger type or a vertical ring spray type desuperheater.

4. A primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat according to claim 1, characterized in that: The low-temperature reheater heat exchanger is a multi-tube annular header structure.

5. The primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat according to claim 1, characterized in that: The high-temperature reheater heat exchanger is a multi-tube annular header structure.

6. A primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat according to claim 1, characterized in that: The desuperheating water pipeline is provided with a regulating valve.

7. A primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat according to claim 1, characterized in that: The dry quenching boiler is a natural circulation boiler or a forced circulation boiler.

8. The primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat according to claim 1, characterized in that: The steam turbine is a pure condensing steam turbine or an extraction condensing steam turbine.

9. The primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat according to claim 1, characterized in that: The condenser is a double-flow condenser provided with a separation water chamber.

10. A primary intermediate reheat power generation system coupling riser waste heat and dry coke quenching waste heat according to claim 1, characterized in that: The deaerator is of low-pressure rotary film type.

Images