A process for recovering kinetic energy from medium-pressure saturated steam generated by waste heat from coke oven riser pipes

Abstract

This invention relates to the field of coke oven riser pipe waste heat utilization technology, specifically to a process for recovering the kinetic energy of medium-pressure saturated steam generated from coke oven riser pipe waste heat. The process includes the following steps: S1, deaerated water is sent to the steam drum for mixing after deaeration by a deaerator; the steam drum water flows out from the lower part of the steam drum and is sent to the riser pipe heater for heating; S2, the riser pipe heater heats the water to produce medium-pressure saturated steam, which absorbs heat from the raw coal and becomes a steam-water mixture before returning to the steam drum; S3, the medium-pressure saturated steam in the upper part of the steam drum is sent to a saturated steam turbine to perform work, and the steam after work is connected to the low-pressure steam main network. This invention avoids the problems of wasted heat exchange area and reduced steam production caused by using riser pipes to heat saturated steam to produce superheated steam. It eliminates the three-stage energy conversion of first producing superheated steam, then generating electricity, and then using electricity to drive equipment. This improves the utilization rate of riser pipe waste heat, meets the demand for low-pressure steam in subsequent workshops, and significantly reduces operating costs.

Description

Technical Field

[0001] This invention relates to the field of waste heat utilization technology in coke oven riser pipes, specifically to a process for recovering the kinetic energy of medium-pressure saturated steam generated from waste heat in coke oven riser pipes. Background Technology

[0002] In recent years, with the increasing demand for energy conservation and consumption reduction in coke ovens, the waste heat recovery system technology of coke oven riser pipe has been widely used in coke oven production. The recovered waste heat generates steam for coking and downstream product production, which can reduce the cost of coke by 6-15 yuan / ton. This technology has become the standard for new and renovated coke ovens in the coking industry.

[0003] Currently, this technology is implemented in two ways: First, it directly produces low-pressure saturated steam at 0.5-0.8 MPa or medium-pressure saturated steam at 1.2-2.0 MPa, then directly depressurizes it to below 1.0 MPa to convert it into low-pressure saturated steam, which is then integrated into the low-pressure steam network or used for heating. Second, it produces saturated steam at 1.2-1.6 MPa through heat exchange, which is then distributed in a steam distributor. A portion is depressurized and enters the deaerator of this system for deoxygenation; another portion enters the rich oil heat exchanger to heat the rich oil to 180°C; another portion enters the ammonia heat exchanger to heat the ammonia water to 120-130°C; and a third portion enters the riser pipe for secondary superheating to generate superheated steam above 400°C, which then enters the wash oil regenerator to regenerate the wash oil. The remaining saturated steam is integrated into the external network, achieving the effect of completely replacing the tubular furnace. Both of these process routes can achieve the goal of recovering waste heat from the coke oven riser pipe.

[0004] With the increasing application of waste heat recovery technologies, the steam supply, especially low-quality, low-pressure saturated steam, within coking plants has gradually shifted from a shortage to a surplus. For example, in a coking plant with an annual output of 1.5 to 2.5 million tons, the surplus steam volume is typically 10 to 20 tons per hour. Finding suitable uses for this surplus steam has become a pressing issue for coking professionals.

[0005] CN202211197526.4 discloses a process for utilizing surplus steam in coking plants. Deoxygenated water is divided into two streams. One stream, pressurized by a boiler feedwater pump, is sent to a dry quenching waste heat boiler. Inside the boiler, it absorbs heat from the circulating gas to generate superheated steam, which is then sent to a turbine generator set in a dry quenching turbine power plant. The superheated steam enters the turbine from the turbine head to generate electricity. The other stream, pressurized by a steam drum feedwater pump, is sent to the steam drum in the coke oven riser system. It mixes with the steam drum water and flows out from the bottom of the steam drum. It is then pressurized by a forced circulation pump and sent to a riser heat exchanger (1) for producing saturated steam. There, it absorbs heat from the raw coal, becomes a steam-water mixture, and returns to the steam drum. The saturated steam at the top of the steam drum is divided into two streams. One stream, after pressure adjustment by a pressure reducing valve, enters a 0.4–0.6 MPa saturated steam network. The other stream enters a riser heat exchanger (2) for superheated steam generation, and then enters the turbine through a make-up steam inlet to generate electricity. The defect of this patent is that (1) the patented technical solution divides the riser heat exchanger into two parts. One part produces 0.4-0.6MPa low-pressure saturated steam and is incorporated into the low-pressure steam network to supplement the low-pressure steam. The other part is used to produce medium-pressure superheated steam and is sent to the dry quenching coke turbine for power generation. (1) The 0.4-0.6MPa low-pressure saturated steam produced directly has a temperature ≤165℃ and a low steam grade. It can only be used for pipeline heating, storage area heating, direct ammonia stripping, etc., and cannot be directly applied to the heating of crude benzene-rich oil, so the application range is narrow; (2) In this patented technical solution, a portion of the riser heater is used to reheat the low-pressure saturated steam produced to produce high-temperature superheated steam. This not only wastes the heat exchange area of ​​the riser heater, but also reduces the total amount of waste heat extracted from the coke oven riser. A large amount of usable waste heat is carried into the subsequent equipment by the raw coal gas, resulting in energy waste. It also causes a decrease in the total steam output and an increase in the operating cost of the riser waste heat recovery device and the subsequent cooling device; (3) The grid-connected low-pressure steam output generated by this patented system is too small and cannot meet the demand for low-pressure steam for other projects. (4) This patent uses the riser heater to generate superheated steam to generate electricity from the steam turbine, and then drives the motor to do work. The energy is converted three times, resulting in a low energy utilization rate of the riser waste heat. Some energy and heat are wasted.

[0006] CN202123295115.2 discloses a short-process device for a riser tube waste heat recovery tubular furnace. It includes a distribution cylinder, a riser tube superheater, a rich oil heat exchanger, an ammonia stripping heat exchanger, a demineralized water pipe, a first condensate tank, a second condensate tank, and several sets of riser tube heat exchange circulation systems. The inlet of the first condensate tank includes only a first inlet A connected to the rich oil heat exchanger and a first inlet B directly connected to the demineralized water pipe. The inlet of the second condensate tank includes only a second inlet A connected to the ammonia stripping heat exchanger and a second inlet B directly connected to the demineralized water pipe. The outlets of the first and second condensate tanks are respectively connected to each set of riser tube heat exchange circulation systems via electric regulating valves. The outlet of the distribution cylinder includes only a distribution cylinder outlet A connected to the riser tube superheater, a distribution cylinder outlet B connected to the rich oil heat exchanger, and a distribution cylinder outlet C connected to the ammonia stripping heat exchanger. The inlet of the distribution cylinder is connected to each set of riser tube heat exchange circulation systems. This device produces saturated steam at 1.2-1.6 MPa through heat exchange, which is then distributed in a steam distribution cylinder. Part of the steam is depressurized and enters the deaerator of this system for deoxygenation; part of the steam enters the rich oil heat exchanger to heat the rich oil to 180°C; part of the steam enters the ammonia heat exchanger to heat the ammonia water to 120-130°C; part of the steam enters the riser pipe for secondary superheating to produce superheated steam above 400°C, which enters the wash oil regenerator to regenerate the wash oil; the remaining saturated steam is incorporated into the external pipeline network, thus achieving the effect of completely replacing the tubular furnace. The defect of this patent is that (1) the patented technical solution divides the riser pipe heat exchanger into two parts. One part produces low-pressure saturated steam at 1.2-1.6 MPa and exchanges heat with the ammonia and rich oil, while the other part is directly depressurized and sent to the deaerator for heating and deoxygenation. The other part is used to produce medium-pressure superheated steam, which is sent to crude benzene to regenerate the wash oil. The production of some low-pressure saturated steam at 1.2-1.6 MPa is directly depressurized and then heated, resulting in a waste of steam kinetic energy. (2) In this patented technical solution, a portion of the riser heater is used to reheat the low-pressure saturated steam produced to produce high-temperature superheated steam. This not only wastes the heat exchange area of ​​the riser heater and reduces the total amount of waste heat extracted from the coke oven riser, but also causes a large amount of usable waste heat to be carried into the downstream equipment by the waste gas, resulting in energy waste. Furthermore, it causes a significant decrease in the total steam output and increases the operating costs of the riser waste heat recovery device and the subsequent cooling device. (3) The grid-connected low-pressure steam output generated by this patented system is too small to meet the demand for low-pressure steam from other projects.

[0007] In summary, existing technologies do not fully and effectively utilize the waste heat from the coke oven riser pipe, resulting in energy waste and increased production costs. Summary of the Invention

[0008] To address the technical problem of ineffective utilization of waste heat from coke oven riser pipes, this invention provides a process for recovering the kinetic energy of medium-pressure saturated steam generated from waste heat in coke oven riser pipes. This process can improve the utilization rate of waste heat from riser pipes, save energy, and reduce production costs.

[0009] This invention provides a process for recovering the kinetic energy of medium-pressure saturated steam generated from waste heat in coke oven riser pipes, comprising the following steps:

[0010] S1. Deoxygenated water is sent to the steam drum for mixing after being deoxygenated by the deaerator. The steam drum water flows out from the bottom of the steam drum and is sent to the riser heater for heating.

[0011] S2, the riser heater heats water to produce medium-pressure saturated steam, which absorbs the heat of raw coal and becomes a steam-water mixture before returning to the steam drum;

[0012] S3. The medium-pressure saturated steam at the top of the steam drum is sent to the saturated steam turbine drive unit to do work, and the steam after doing work is connected to the low-pressure steam main network.

[0013] Furthermore, in step S1, the conductivity of the demineralized water is <5 μS / cm.

[0014] Furthermore, the steam used by the deaerator in step S1 comes from the low-pressure steam main network or the steam after work is done in step S3. The water temperature after deaeration by the deaerator is 103.5 to 105°C to ensure good thermal deaeration effect.

[0015] Furthermore, in step S2, the pressure of the medium-pressure saturated steam is 1.8–3.0 MPa (gauge pressure). All the steam generated by the riser heaters of this invention is medium-pressure saturated steam, with a pressure of 1.8–3.0 MPa (gauge pressure), and the steam has not undergone secondary heating or superheating treatment.

[0016] Furthermore, in step S3, the saturated steam turbine drive device includes a saturated steam turbine unit and the driven equipment.

[0017] Furthermore, in step S3, the saturated steam turbine drive device includes one of the following: saturated steam turbine unit + electric motor drive + driven equipment, saturated steam turbine unit + electric motor drive + driven equipment + reverse power generation device, or saturated steam turbine unit + driven equipment + reverse power generation device.

[0018] Furthermore, in step S3, the driven equipment includes one of the following: a circulating water pump, a cryogenic water pump, a circulating ammonia water pump, a gas blower, a desulfurization liquid circulating pump, and a large mother liquor pump.

[0019] Furthermore, in step S2, the pressure of the medium-pressure saturated steam is reduced to 0.6-1.0 MPa (gauge pressure) after it performs work, so as to ensure that the low-pressure steam has sufficient temperature and grade and avoid affecting the operation of ammonia stripping, crude benzene and other steam-using units.

[0020] Furthermore, the present invention employs the following apparatus: including a deaerator, a steam drum, a riser heater, and a saturated steam turbine drive device;

[0021] The bottom inlet of the deaerator is connected to the demineralized water inlet pipe, and the bottom outlet of the deaerator is connected to the bottom inlet of the steam drum through a pipe.

[0022] The steam turbine drive unit includes a saturated steam turbine unit. The bottom outlet of the steam drum is connected to the inlet of the riser heater through a pipeline. The outlet of the riser heater is connected to the steam inlet of the saturated steam turbine unit through a pipeline. The steam outlet of the saturated steam turbine unit is connected to the low-pressure steam main network through a pipeline.

[0023] Furthermore, the saturated steam turbine drive unit is equipped with a bypass pipeline. From the high-pressure side to the low-pressure side, a remote pressure gauge, a regulating valve, and a pressure-reducing valve are sequentially installed on the bypass pipeline. The remote pressure gauge and the regulating valve are pressure-interlocked. The purpose is to automatically open or close the regulating valve to reduce pressure when the intermediate-pressure saturated steam exceeds the set range, thus preventing the saturated steam turbine drive unit from operating under overload conditions.

[0024] The beneficial effects of this invention are as follows: The coke oven riser pipe waste heat to produce medium-pressure saturated steam kinetic energy recovery process provided by this invention uses the medium-pressure saturated steam produced by the coke oven riser pipe to directly drive the equipment to do work, avoiding the problems of wasted heat exchange area and reduced steam production caused by using the riser pipe to heat saturated steam to produce superheated steam. It eliminates the three-stage energy conversion of first producing superheated steam, then generating electricity, and then using electricity to drive the equipment. This not only improves the utilization rate of riser pipe waste heat, but also meets the demand for low-pressure steam in subsequent workshops, and significantly reduces operating costs. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a specific embodiment of the present invention.

[0027] In the diagram, 1-deaerator feedwater pump, 2-deaerator, 3-steam drum feedwater pump, 4-steam drum, 5-forced circulation pump, 6-riser heater, 7-saturated steam turbine drive unit, 8-regulating valve, 9-pressure reducing valve. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0029] Example 1

[0030] like Figure 1 The coke oven riser pipe waste heat to produce medium-pressure saturated steam kinetic energy recovery process provided by the present invention adopts the following device: including deaerator 2, steam drum 4, riser pipe heater 6, and saturated steam turbine drive device 7.

[0031] The bottom inlet of deaerator 2 is connected to the demineralized water inlet pipe, and the demineralized water inlet pipe is equipped with a deaerator water supply pump 1. The bottom outlet of deaerator 2 is connected to the bottom inlet of steam drum 4 through a pipe, and the pipe connecting deaerator 2 and steam drum 4 is equipped with a steam drum water supply pump 3.

[0032] The saturated steam turbine drive unit 7 includes a saturated steam turbine unit and the driven equipment. The bottom outlet of the steam drum 4 is connected to the inlet of the riser heater 6 through a pipeline. A forced circulation pump 5 is installed on the pipeline connecting the steam drum 4 and the riser heater 6. The outlet of the riser heater 6 is connected to the steam inlet of the saturated steam turbine unit through a pipeline. The steam outlet of the saturated steam turbine unit is connected to the low-pressure steam main pipeline through a pipeline.

[0033] The saturated steam turbine drive unit 7 is equipped with a bypass pipeline. From the high-pressure side to the low-pressure side, a remote pressure gauge, a regulating valve 8, and a pressure reducing valve 9 are installed in sequence on the bypass pipeline. The remote pressure gauge and the regulating valve 8 are pressure interlocked. When the intermediate-pressure steam pressure exceeds the first set threshold, the regulating valve 8 is automatically opened to reduce the pressure and prevent the saturated steam turbine drive unit 7 from operating under overload. When the intermediate-pressure steam pressure is lower than the second set threshold, the regulating valve 8 is automatically closed to stop the bypass pressure reduction and ensure that the saturated steam turbine drive unit 7 has enough steam to do work.

[0034] Example 2

[0035] Taking the waste heat recovery process of a 1.5 million tons / year coke oven riser pipe to drive the circulating water pump in the chemical production workshop as an example, the coke oven riser pipe waste heat production medium-pressure saturated steam kinetic energy recovery process provided by this invention includes the following steps:

[0036] Demineralized water (conductivity <5µs / cm) is pumped to the deaerator water inlet by the deaerator feedwater pump and undergoes high-temperature deaeration inside the deaerator. The deaerated water, with a temperature of approximately 104℃, is discharged from the bottom outlet of the deaerator, pressurized by the steam drum feedwater pump, and sent to the steam drum. After mixing with the steam drum water, it flows out from the bottom of the steam drum and is pressurized by the forced circulation pump to the riser heater to produce medium-pressure saturated steam at 2.2 MPa (gauge pressure). After absorbing the heat of the raw coal and becoming a steam-water mixture, it returns to the steam drum. The 2.2 MPa (gauge pressure) medium-pressure saturated steam at the top of the steam drum is sent to the saturated steam turbine drive unit to perform work. The saturated steam turbine drive unit is a saturated steam turbine unit (output power 366 kW) + circulating water pump (matching power 366 kW). After performing work, the steam pressure drops to 1.0 MPa (gauge pressure) and is connected to the low-pressure steam main network for heating in coking and other units. The saturated steam turbine drive unit 7 is equipped with a steam bypass pipeline. Excess steam is regulated and reduced to 1.0 MPa (gauge pressure) through the bypass pipeline before being connected to the low-pressure steam main network.

[0037] In this embodiment, all the steam generated by the riser heaters is medium-pressure saturated steam at 2.2 MPa, and the steam has not undergone secondary heating or superheating treatment. The medium-pressure steam production reaches approximately 15.7 t / h, and the steam production per ton of coke is approximately 100 kg. In this embodiment, the low-pressure saturated steam after being depressurized by the saturated steam turbine drive device has a pressure of 1.0 MPa and a steam volume of 15 t / h. All the low-pressure steam is connected to the low-pressure steam pipeline network for heating in the chemical production workshop and other equipment.

[0038] Example 3

[0039] Taking the waste heat recovery process of a 1.5 million tons / year coke oven riser pipe to drive the circulating ammonia water pump in the chemical production workshop as an example, the coke oven riser pipe waste heat production medium-pressure saturated steam kinetic energy recovery process provided by this invention includes the following steps:

[0040] Demineralized water (conductivity <5µs / cm) is pumped to the deaerator water inlet via the deaerator feedwater pump and undergoes high-temperature deaeration inside the deaerator. The deaerated water, with a temperature of approximately 103°C, is discharged from the bottom outlet of the deaerator, pressurized by the steam drum feedwater pump, and sent to the steam drum. After mixing with the steam drum water, it flows out from the bottom of the steam drum and is pressurized by the forced circulation pump to the riser heater to produce medium-pressure saturated steam at 2.8 MPa (gauge pressure). After absorbing the heat of the raw coal and becoming a steam-water mixture, it returns to the steam drum. The 2.8 MPa (gauge pressure) medium-pressure saturated steam at the top of the steam drum is sent to the saturated steam turbine drive unit to perform work. The saturated steam turbine drive unit consists of a saturated steam turbine unit (output power 366 kW) + a circulating ammonia pump (matching power 315 kW) + a reverse generator (matching power 50 kW). After performing work, the steam pressure drops to 0.8 MPa (gauge pressure) and is connected to the low-pressure steam main network for heating in coking and other units. The saturated steam turbine drive unit 7 is equipped with a steam bypass pipeline. Excess steam is regulated and reduced to 0.8 MPa (gauge pressure) through the bypass pipeline before being connected to the low-pressure steam main network.

[0041] In this embodiment, all the steam generated by the riser heaters is medium-pressure saturated steam at 2.8 MPa, and the steam does not undergo secondary heating or superheating treatment. The medium-pressure steam production reaches approximately 15.7 t / h, and the steam production per ton of coke is approximately 100 kg. In this embodiment, the low-pressure saturated steam after being depressurized by the saturated steam turbine drive device has a pressure of 0.8 MPa and a steam volume of 15.2 t / h. All the low-pressure steam is connected to the low-pressure steam pipeline network for heating in the chemical production workshop and other equipment.

[0042] Example 4

[0043] Taking the waste heat recovery process of a 1.5 million tons / year coke oven riser pipe to drive the circulating water pump in the chemical production workshop as an example, the coke oven riser pipe waste heat production medium-pressure saturated steam kinetic energy recovery process provided by this invention includes the following steps:

[0044] Demineralized water (conductivity <5µs / cm) is pumped to the deaerator water inlet by the deaerator feedwater pump and undergoes high-temperature deaeration inside the deaerator. The deaerated water, with a temperature of approximately 104℃, is discharged from the bottom outlet of the deaerator, pressurized by the steam drum feedwater pump, and sent to the steam drum. After mixing with the steam drum water, it flows out from the bottom of the steam drum and is pressurized by the forced circulation pump to the riser heater to produce medium-pressure saturated steam at 2.0 MPa (gauge pressure). After absorbing the heat of the raw coal and becoming a steam-water mixture, it returns to the steam drum. The 2.0 MPa (gauge pressure) medium-pressure saturated steam at the top of the steam drum is sent to the saturated steam turbine drive unit to perform work. The saturated steam turbine drive unit is a saturated steam turbine unit (output power 366 kW) + circulating water pump (matching power 450 kW). After performing work, the steam pressure drops to 0.8 MPa (gauge pressure) and is connected to the low-pressure steam main network for heating in coking and other units. The saturated steam turbine drive unit 7 is equipped with a steam bypass pipeline. Excess steam is regulated and reduced to 0.8 MPa (gauge pressure) through the bypass pipeline before being connected to the low-pressure steam main network.

[0045] In this embodiment, the steam drum is designed to a pressure of 2.5 MPa. All the steam generated by the riser heaters is medium-pressure saturated steam at 2.0 MPa, and the steam does not undergo secondary heating or superheating treatment. The medium-pressure steam production reaches approximately 15.7 t / h, and the steam production per ton of coke is approximately 100 kg. In this embodiment, the low-pressure saturated steam pressure after being depressurized by the saturated steam turbine drive device is 0.8 MPa, and all the low-pressure steam is connected to the low-pressure steam pipeline network.

[0046] Comparative Example 1

[0047] The difference between Comparative Example 1 and Example 4 is that the saturated steam in the steam drum is directly reduced to 0.8 MPa by a pressure reducing valve. Part of it (about 1.9 t / h) is used for heating the deaerator, and the remaining about 13.8 t / h is supplied to the low-pressure steam main network. The saturated steam turbine is not used to drive the work.

[0048] Comparative Example 2

[0049] The difference between Comparative Example 2 and Example 4 is that the portion of the medium-pressure saturated steam at 2.0 MPa in the steam drum (approximately 8 t / h) is sent to the crude benzene to heat the rich oil; the remaining medium-pressure saturated steam is depressurized to 0.8 MPa, and part of it (approximately 1.9 t / h) is used for deaerator heating, while the remaining approximately 1 t / h is supplied to the low-pressure steam main network, without being used for saturated steam turbine drive devices to perform work.

[0050] The economic benefits generated by using the schemes of Example 4, Comparative Example 1, and Comparative Example 2 are shown in Table 1.

[0051] Table 1. Specific data on the economic benefits generated by each scheme.

[0052]

[0053] As shown in Table 1, the medium-pressure saturated steam produced by the riser pipe in Embodiment 4 of the present invention directly drives the equipment to perform work with higher economic efficiency than other schemes, and the operating cost of coke products is significantly reduced.

[0054] This invention utilizes a portion of the kinetic energy of the medium-pressure steam generated from the waste heat of the riser pipe to directly drive the equipment, converting some kinetic energy into mechanical energy. This results in higher energy utilization and avoids the waste of steam kinetic energy caused by direct pressure reduction, leading to significant energy savings. Table 2 shows the rated output power of the equipment driven by saturated medium-pressure steam under different operating conditions, based on theoretical calculations.

[0055] Table 2. Rated output power data of saturated medium-pressure steam-driven equipment under different operating conditions.

[0056]

[0057] As shown in Table 2, the saturated medium-pressure steam produced by this invention has a large kinetic energy. Utilizing this kinetic energy to do work can meet the needs of actual production and achieve the goal of energy saving and consumption reduction.

[0058] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A process for recovering the kinetic energy of medium-pressure saturated steam generated from waste heat in a coke oven riser pipe, characterized in that, Includes the following steps, S1. Deoxygenated water is sent to the steam drum for mixing after being deoxygenated by the deaerator. The steam drum water flows out from the bottom of the steam drum and is sent to the riser heater for heating. S2, the riser heater heats the water, absorbs the heat of the raw coal and turns it into a steam-water mixture, which then returns to the steam drum after producing medium-pressure saturated steam. S3. The medium-pressure saturated steam at the top of the steam drum is sent to the saturated steam turbine drive unit to do work, and the steam after doing work is connected to the low-pressure steam main network; the pressure of the medium-pressure saturated steam is 1.8~3.0MPa, and the steam has not undergone secondary heating or superheating treatment; The saturated steam turbine drive device includes a saturated steam turbine unit and the driven equipment; the saturated steam turbine drive device is one of the following: saturated steam turbine unit + electric motor drive + driven equipment, saturated steam turbine unit + electric motor drive + driven equipment + reverse power generation device, or saturated steam turbine unit + driven equipment + reverse power generation device.

2. The coke oven riser pipe waste heat to produce medium-pressure saturated steam kinetic energy recovery process as described in claim 1, characterized in that, In step S1, the conductivity of the demineralized water is <5 μS / cm.

3. The coke oven riser pipe waste heat to produce medium-pressure saturated steam kinetic energy recovery process as described in claim 1, characterized in that, The steam used by the deaerator in step S1 comes from the low-pressure steam main network or the steam after work is done in step S3. The water temperature after deaeration by the deaerator is 103.5~105℃.

4. The coke oven riser pipe waste heat to produce medium-pressure saturated steam kinetic energy recovery process as described in claim 1, characterized in that, In step S2, the pressure of the medium-pressure saturated steam is 1.8~3.0 MPa.

5. The coke oven riser pipe waste heat to produce medium-pressure saturated steam kinetic energy recovery process as described in claim 1, characterized in that, In step S3, the driven equipment is one of the following: circulating water pump, cryogenic water pump, circulating ammonia water pump, gas blower, desulfurization liquid circulating pump, and large mother liquor pump.

6. The coke oven riser pipe waste heat to produce medium-pressure saturated steam kinetic energy recovery process as described in claim 1, characterized in that, In step S2, the pressure of the medium-pressure saturated steam is reduced to 0.6~1.0MPa after it does work.

7. The coke oven riser pipe waste heat to produce medium-pressure saturated steam kinetic energy recovery process as described in claim 1, characterized in that, The following equipment is used: including a deaerator, steam drum, riser heater, and saturated steam turbine drive unit; The bottom inlet of the deaerator is connected to the demineralized water inlet pipe, and the bottom outlet of the deaerator is connected to the bottom inlet of the steam drum through a pipe. The steam turbine drive unit includes a saturated steam turbine unit. The bottom outlet of the steam drum is connected to the inlet of the riser heater through a pipeline. The outlet of the riser heater is connected to the steam inlet of the saturated steam turbine unit through a pipeline. The steam outlet of the saturated steam turbine unit is connected to the low-pressure steam main network through a pipeline.

8. The coke oven riser pipe waste heat to produce medium-pressure saturated steam kinetic energy recovery process as described in claim 7, characterized in that, The saturated steam turbine drive unit is equipped with a bypass pipeline. From the high-pressure side to the low-pressure side, a remote pressure gauge, a regulating valve, and a pressure reducing valve are installed in sequence on the bypass pipeline. The remote pressure gauge and the regulating valve are interlocked.

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