A steam-water injection type temperature and pressure reduction device and method

Abstract

The present invention relates to a steam-water injection type temperature reduction and pressure reduction device and method, comprising a high-temperature and high-pressure steam inlet pipe 1, a temperature reduction water inlet pipe 2, a rotary atomizer 3, a Rafale nozzle 4, a receiving chamber 8, a mixing tube 10 and a diffuser 12; the outlet of the high-temperature and high-pressure steam inlet pipe 1 is connected to the Rafale nozzle 4, the outlet of the temperature reduction water inlet pipe 2 is connected to the rotary atomizer 3, the outlet of the rotary atomizer 3 and the outlet of the Rafale nozzle 4 are both connected to one end of the receiving chamber 8; the other end of the receiving chamber 8 is connected to the mixing tube 10 and the diffuser 12 in sequence. By reducing the temperature and pressure of steam through the present invention, the mixing time of steam and water is effectively shortened, and the length of the mixing tube and the diffuser is shortened, thereby reducing the operating cost and energy consumption.

Description

Technical Field

[0001] The invention relates to the technical field of steam temperature and pressure reduction, and in particular to a low-energy consumption steam-water injection type temperature and pressure reduction device and method. Background Art

[0002] The desuperheater and pressure reducer is used to reduce high-temperature and high-pressure steam to low-pressure and low-temperature superheated steam or saturated steam that can meet the use of equipment. Taking the denitrification urea hydrolyzer of a thermal power plant as an example, the steam required by the hydrolyzer is about 0.7MPa and 165℃, but the auxiliary steam of the power plant boiler is basically 0.8-3.0MPa, and the temperature is basically 280-350℃; if the high-temperature and high-pressure steam directly enters the urea hydrolyzer, it will cause the failure of the hydrolyzer equipment and even damage the hydrolyzer equipment, greatly reducing the service life of the hydrolyzer; at the same time, it will cause urea to not be completely decomposed into ammonia and carbon dioxide, resulting in a waste of urea resources and reducing the efficiency of the hydrolyzer. Taking the steam at the outlet of the superheater of a thermal power plant as an example, the steam generated by the boiler is further heated by the superheater and then enters the steam turbine to do work, but the steam turbine is more sensitive to the temperature and pressure of the steam. If the steam parameters are greater than the upper limit of the steam parameters required by the steam turbine, it will cause damage to the steam turbine and also cause greater safety hazards. Therefore, it is necessary to use a desuperheater and pressure reducer to reduce the temperature and pressure to an appropriate range.

[0003] Traditional temperature and pressure reduction devices have problems such as small adjustable flow range and high noise and vibration. They also have complex structure, large size, high precision requirements for components and high energy consumption for system operation. Summary of the invention

[0004] The object of the present invention is to provide a steam-water injection type temperature reduction and pressure reduction device and method, the temperature reduction and pressure reduction device has a simple and reasonable structure, a high degree of equipment integration, simple operation and reliable operation.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A steam-water injection type temperature and pressure reduction device comprises a high-temperature and high-pressure steam inlet pipe, a temperature-reducing water inlet pipe, a rotary atomizer, a Rafale nozzle, a receiving chamber, a mixing tube and a pressure diffuser; the outlet of the high-temperature and high-pressure steam inlet pipe is connected to the Rafale nozzle, the outlet of the temperature-reducing water inlet pipe is connected to the rotary atomizer, the outlet of the rotary atomizer and the outlet of the Rafale nozzle are both connected to one end of the receiving chamber; the other end of the receiving chamber is connected to the mixing tube and the pressure diffuser in sequence.

[0007] The aforementioned steam-water injection type temperature and pressure reduction device, the rotary atomizer is composed of a plurality of guide blades with the same rotation direction and angle, an outer cylindrical tube and an inner cylindrical tube.

[0008] In the aforementioned steam-water injection type temperature and pressure reduction device, the angle between the guide vane and the axis of the rotary atomizer is 15°-75°.

[0009] In the aforementioned steam-water injection type temperature and pressure reduction device, the receiving chamber, the mixing tube and the diffuser tube are integrally in the form of a Rafale tube.

[0010] A steam-water injection type temperature reduction and pressure reduction method, using the aforementioned steam-water injection type temperature reduction and pressure reduction device, the steps are as follows:

[0011] S1 High-temperature and high-pressure steam enters the Rafale nozzle through the high-temperature and high-pressure steam inlet pipe, and forms a low-pressure and reflux zone in the receiving chamber after being ejected;

[0012] S2 The desuperheated water enters the rotary atomizer through the desuperheated water inlet pipe and is atomized into small droplets, which rotate at high speed around the Rafale nozzle. Due to the low pressure formed in step S1, the small droplets are ejected into the receiving chamber;

[0013] The steam sprayed from the nozzle S3 and the small droplets of desuperheated water in step S2 are contacted and mixed in the reflux area of ​​the receiving chamber to exchange heat, and the high-temperature and high-pressure steam is converted into superheated steam with relatively low temperature and pressure;

[0014] S4: The mixture of the desuperheated water droplets and the superheated steam generated in step S3 enters the mixing tube from the receiving chamber for further mixing and heat transfer, thereby further reducing the temperature of the steam;

[0015] S5: The steam generated in step S4 enters the diffuser from the mixing tube, where the steam velocity decreases and the pressure increases, forming steam suitable for use.

[0016] The cooling water droplets partially evaporate in the receiving chamber and continue to evaporate in the mixing tube, thereby cooling the high-temperature and high-pressure steam through a secondary evaporation process.

[0017] Compared with the prior art, the present invention is beneficial in that:

[0018] The rotary atomizer is used to atomize the cooling water, which has a simple and stable structure, reduces the number of cooling water inlets and corresponding pipe connections, and reduces the number of cooling water atomization devices;

[0019] Since there is a reflux zone in the receiving chamber, the contact time between steam and cooling water in the receiving chamber can be prolonged, the heat transfer effect is better, and cooling and pressure reduction can be achieved in a very short time and a very short distance, so that when the steam and cooling water mixture enters the mixing tube, the temperature and pressure are close to the design value, thereby shortening the length of the mixing tube and the diffuser; moreover, the receiving chamber, the mixing tube and the diffuser are in the form of a Rafale tube as a whole, and the Rafale tube is used to reduce the steam pressure and increase the flow velocity, so that the steam and cooling water droplets are intensely mixed in the receiving chamber and the mixing tube, and fully contact to carry out strong energy and momentum conversion, effectively shortening the mixing time of steam and water, and also shortening the length of the mixing tube and the diffuser; compared with the cooling and pressure reducing device of the same specification, the length of the mixing tube and the diffuser can be shortened by about 30%;

[0020] The present invention can adjust the flow rate of high-temperature and high-pressure steam by adjusting the size of the Laval nozzle, and adjust the flow rate of the desuperheating water so as to accurately reduce the final steam temperature and pressure to the design value, thereby improving the desuperheating and decompression accuracy and also increasing the adjustable range of the steam flow rate;

[0021] The steam-water injection method of temperature and pressure reduction is adopted. The temperature and pressure reduction process is carried out simultaneously in the device. Compared with the method of first reducing pressure and then cooling, the operation process is simplified.

[0022] The steam-water injection cooling and decompression method is adopted to simplify the overall structure of the cooling and decompression device, reduce the use of complex structural accessories and auxiliary devices in the cooling and decompression process, and has the advantages of simple device structure, convenient operation, small size, and small space occupied after installation. At the same time, because there are no mechanical transmission parts in the device, the structure is simple, the operation is stable, and the inspection and maintenance are convenient, which reduces the operating cost and energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of an embodiment of a temperature and pressure reduction device of the present invention;

[0024] Figure 2 Schematic diagram of the preferred structure of the rotary atomizer of the present invention.

[0025] Figure markings: 1-high-temperature and high-pressure steam inlet pipe, 2-cooling water inlet pipe, 3-rotary atomizer, 4-Rafale nozzle, 5-Rafale nozzle throat, 6-Rafale nozzle outlet section, 7-reflux zone, 8-receiving chamber, 9-receiving chamber and mixing tube interface, 10-mixing tube, 11-mixing tube and diffuser interface, 12-diffuser, 13-diffuser outlet interface, 14-guide vanes, 15-outer cylindrical barrel, 16-inner cylindrical barrel, A-high-temperature and high-pressure steam inlet, B-cooling water inlet, C-steam outlet. DETAILED DESCRIPTION

[0026] Embodiment 1 of the present invention: Figure 1 As shown, a steam-water injection type temperature and pressure reduction device comprises a high-temperature and high-pressure steam inlet pipe 1, a temperature-reducing water inlet pipe 2, a rotary atomizer 3, a Rafale nozzle 4, a receiving chamber 8, a mixing tube 10 and a pressure diffuser 12; the outlet of the high-temperature and high-pressure steam inlet pipe 1 is connected to the Rafale nozzle 4, the outlet of the temperature-reducing water inlet pipe 2 is connected to the rotary atomizer 3, the outlet of the rotary atomizer 3 and the outlet of the Rafale nozzle 4 are both connected to one end of the receiving chamber 8; the other end of the receiving chamber 8 is connected to the mixing tube 10 and the pressure diffuser 12 in sequence; the receiving chamber 8, the mixing tube 10 and the pressure diffuser 12 are in the form of a Rafale tube as a whole. Among them, the outlet section 6 of the Rafale nozzle 4 can be arranged in the receiving chamber 8.

[0027] Example 2: Figure 1 As shown, a steam-water injection type temperature and pressure reduction device comprises a high-temperature and high-pressure steam inlet pipe 1, a temperature-reducing water inlet pipe 2, a rotary atomizer 3, a Rafale nozzle 4, a receiving chamber 8, a mixing pipe 10 and a pressure diffuser 12; the outlet of the high-temperature and high-pressure steam inlet pipe 1 is connected to the Rafale nozzle 4, the outlet of the temperature-reducing water inlet pipe 2 is connected to the rotary atomizer 3, the outlet of the rotary atomizer 3 and the outlet of the Rafale nozzle 4 are both connected to one end of the receiving chamber 8; the other end of the receiving chamber 8 is connected to the mixing pipe 10 and the pressure diffuser 12 in sequence. Among them, the outlet section 6 of the Rafale nozzle 4 can be arranged in front of the inlet of the receiving chamber 8.

[0028] Example 3: Figure 1 and Figure 2 As shown, a steam-water injection type temperature and pressure reduction device comprises a high-temperature and high-pressure steam inlet pipe 1, a cooling water inlet pipe 2, a rotary atomizer 3, a Rafale nozzle 4, a receiving chamber 8, a mixing tube 10 and a diffuser 12; the outlet of the high-temperature and high-pressure steam inlet pipe 1 is connected to the Rafale nozzle 4, the outlet of the cooling water inlet pipe 2 is connected to the rotary atomizer 3, the outlet of the rotary atomizer 3 and the outlet of the Rafale nozzle 4 are both connected to one end of the receiving chamber 8; the other end of the receiving chamber 8 is connected to the mixing tube 10 and the diffuser 12 in sequence; the rotary atomizer 3 is composed of a plurality of guide blades 14, an outer cylindrical tube 15 and an inner cylindrical tube 16 with the same rotation direction and angle; the angle between the guide blade 14 and the axis of the rotary atomizer 3 is 15°-40°.

[0029] The larger the angle between the guide vane 14 and the axis of the rotary atomizer 3 is, the better the atomization effect is. However, the larger the angle is, the greater the resistance is. Therefore, the appropriate angle is comprehensively selected according to the working conditions.

[0030] Example 4: Figure 1 and Figure 2As shown, a steam-water injection type temperature and pressure reduction device comprises a high-temperature and high-pressure steam inlet pipe 1, a cooling water inlet pipe 2, a rotary atomizer 3, a Rafale nozzle 4, a receiving chamber 8, a mixing tube 10 and a diffuser 12; the outlet of the high-temperature and high-pressure steam inlet pipe 1 is connected to the Rafale nozzle 4, the outlet of the cooling water inlet pipe 2 is connected to the rotary atomizer 3, the outlet of the rotary atomizer 3 and the outlet of the Rafale nozzle 4 are both connected to one end of the receiving chamber 8; the other end of the receiving chamber 8 is connected to the mixing tube 10 and the diffuser 12 in sequence; the rotary atomizer 3 is composed of a plurality of guide vanes 14, an outer cylindrical tube 15 and an inner cylindrical tube 16 with the same rotation direction and angle; the angle between the guide vane and the axis of the rotary atomizer is 50°-75°; the receiving chamber 8, the mixing tube 10 and the diffuser 12 are in the form of a Rafale tube as a whole.

[0031] Example 5: Figure 1 and Figure 2 As shown, a steam-water injection type temperature and pressure reduction device comprises a high-temperature and high-pressure steam inlet pipe 1, a cooling water inlet pipe 2, a rotary atomizer 3, a Rafale nozzle 4, a receiving chamber 8, a mixing tube 10 and a diffuser 12; the outlet of the high-temperature and high-pressure steam inlet pipe 1 is connected to the Rafale nozzle 4, the outlet of the cooling water inlet pipe 2 is connected to the rotary atomizer 3, the outlet of the rotary atomizer 3 and the outlet of the Rafale nozzle 4 are both connected to one end of the receiving chamber 8; the other end of the receiving chamber 8 is connected to the mixing tube 10 and the diffuser 12 in sequence; the rotary atomizer 3 is composed of a plurality of guide blades 14, an outer cylindrical tube 15 and an inner cylindrical tube 16 with the same rotation direction and angle; the angle between the guide blade and the axis of the rotary atomizer is 35°-55°.

[0032] Embodiment 6: A steam-water injection type temperature and pressure reduction method, using Figure 1 The steam-water injection type temperature and pressure reduction device shown in the figure has the following steps:

[0033] S1 high-temperature and high-pressure steam enters the Rafale nozzle 4 through the high-temperature and high-pressure steam inlet pipe 1, and uses the properties of the Rafale tube to reduce steam pressure and increase flow velocity, forming a low-pressure and reflux zone 7 in the receiving chamber 8 after being ejected;

[0034] S2 The desuperheated water enters the rotary atomizer 3 through the desuperheated water inlet pipe 2 and is atomized into small droplets, which rotate at high speed around the Rafale nozzle 4. Due to the low pressure formed in step S1, the small droplets are ejected into the receiving chamber 8;

[0035] The steam sprayed from the nozzle S3 and the small droplets of cooling water in step S2 are contacted and mixed in the reflux zone 7 of the receiving chamber 8 to exchange heat. Part of the small droplets of cooling water are evaporated, and the high-temperature and high-pressure steam is converted into superheated steam with relatively low temperature and pressure.

[0036] Since there is a reflux zone 7 in the receiving chamber 8, the steam and the desuperheated water can fully contact and exchange heat inside the receiving chamber 8, and the heat transfer effect is better, so the temperature and pressure can be reduced in a very short time and a very short distance;

[0037] S4: The mixture of the desuperheated water droplets and the superheated steam generated in step S3 enters the mixing tube 10 from the receiving chamber 8 for further mixing and heat transfer, and the desuperheated water droplets continue to evaporate, thereby further reducing the temperature of the steam;

[0038] S5 The steam generated in step S4 enters the diffuser tube 12 from the mixing tube 10, where the steam velocity decreases and the pressure increases to form steam suitable for use;

[0039] When the steam and desuperheated water mixture enters the mixing tube 10, the temperature and pressure are close to the design value, so the requirements can be met by passing through a shorter diffuser tube 12. The lengths of the mixing tube 10 and the diffuser tube 12 are mainly determined by the designed steam volume.

[0040] The working principle of an embodiment of the present invention:

[0041] like Figure 1 and Figure 2 As shown, high temperature and high pressure steam P P First, the high-temperature and high-pressure steam enters the Rafale nozzle 4 from the high-temperature and high-pressure steam inlet pipe 1. Due to the effect of the Rafale nozzle, the steam pressure increases from P P Reduce to the same pressure P as the desuperheating water inlet h , the steam flow rate is greatly improved; at the same time, after the cooling water passes through the rotary atomizer 3, it is atomized into small droplets due to the centrifugal force and rotates at high speed around the Rafale nozzle 4.

[0042] After the steam flows through the nozzle, it draws the cooling water droplets forward, and the mixture fills the entire cross section at the steam inlet in the receiving chamber 8. As the distance between the steam-water mixture and the nozzle outlet cross section increases, the steam pressure at the outlet of the receiving chamber 8 decreases to P2, and at the same time, a low pressure is formed in the receiving chamber 8, so that the cooling water is ejected into the receiving chamber 8; due to the high steam velocity, a reflow zone 7 is formed in the receiving chamber 8, so that the steam and the cooling water droplets are fully in contact, and the energy and momentum conversion between the steam and the droplets is strengthened, so that the cooling water evaporates quickly, the steam temperature drops quickly, and the heat transfer effect is better, so that the cooling and pressure reduction can be achieved in a very short time and a very short distance, and the mixing distance is greatly shortened. Part of the cooling water is evaporated in the receiving chamber 8, and at this time, the high-temperature and high-pressure steam becomes superheated steam with relatively low temperature and pressure.

[0043] Since the pressure P2 at the outlet of the receiving chamber 8 is lower than the pressure P2 at the inlet of the cooling water h, under the action of pressure difference and high-speed steam entrainment, the steam-water mixture enters the mixing tube 10. The receiving chamber 8, the mixing tube 10 and the diffuser 12 are in the form of a Rafale tube, so that the steam-water mixture is violently mixed in the mixing tube 10, and energy and momentum are exchanged. The small droplets of cooling water are basically evaporated, accompanied by a pressure increase. At the outlet of the mixing tube 10, the pressure of the steam-water mixture increases to P3, so that the steam temperature is further reduced, and the velocity field gradually tends to be balanced.

[0044] After the steam enters the diffuser tube 12 from the mixing tube 10, the steam velocity gradually decreases due to the gradual increase in the cross-section of the diffuser tube 12, and the pressure further increases to P c , the temperature is further reduced, and finally steam suitable for use by corresponding equipment is formed at the outlet of the diffuser pipe 12.

[0045] After passing through the temperature and pressure reduction device of the present invention, the pressure of the high-temperature and high-pressure steam increases from P to P Reduce to P c , the cooling water is completely evaporated, and finally the steam after cooling and pressure reduction is output from the diffuser pipe 12 at a certain temperature and pressure.

Claims

1. A steam-water injection type temperature and pressure reduction method, characterized in that: Here are the steps: The method adopts a steam-water injection type temperature and pressure reduction device, comprising a high-temperature and high-pressure steam inlet pipe (1), a temperature-reducing water inlet pipe (2), a rotary atomizer (3), a Rafale nozzle (4), a receiving chamber (8), a mixing tube (10) and a diffuser (12); the outlet of the high-temperature and high-pressure steam inlet pipe (1) is connected to the Rafale nozzle (4), the outlet of the temperature-reducing water inlet pipe (2) is connected to the rotary atomizer (3), the outlet of the rotary atomizer (3) and the outlet of the Rafale nozzle (4) are both connected to one end of the receiving chamber (8); the other end of the receiving chamber (8) is connected to the mixing tube (10) and the diffuser (12) in sequence; the rotary atomizer (3) is composed of a plurality of guide blades (14) having the same rotation direction and angle, an outer cylindrical tube (15) and an inner cylindrical tube (16); S1 High-temperature and high-pressure steam enters the Laval nozzle (4) through the high-temperature and high-pressure steam inlet pipe (1), and after being ejected, forms a low-pressure and reflow zone (7) in the receiving chamber (8); S2 The desuperheated water enters the rotary atomizer (3) through the desuperheated water inlet pipe (2) and is atomized into small droplets, which rotate at high speed around the Rafale nozzle (4). Due to the low pressure formed in step S1, the small droplets are ejected into the receiving chamber (8); S3 The steam sprayed from the nozzle and the small droplets of desuperheated water in step S2 are contacted and mixed in the reflux zone (7) of the receiving chamber (8) to exchange heat, and the high-temperature and high-pressure steam is converted into superheated steam with relatively low temperature and pressure; S4: The mixture of the desuperheated water droplets and the superheated steam generated in step S3 enters the mixing pipe (10) from the receiving chamber (8) for further mixing and heat transfer, thereby further reducing the temperature of the steam; S5 The steam generated in step S4 enters the diffuser tube (12) from the mixing tube (10), the steam velocity decreases, the pressure increases, and steam suitable for use is formed.

2. The steam-water injection type temperature and pressure reduction method according to claim 1, characterized in that: The included angle between the guide vane (14) of the steam-water injection type temperature and pressure reduction device and the axis of the rotary atomizer (3) is 15°-75°.

3. The steam-water injection type temperature and pressure reduction method according to claim 1, characterized in that: The receiving chamber (8), the mixing tube (10) and the diffuser tube (12) of the steam-water injection type temperature and pressure reduction device are in the form of a Rafale tube as a whole.

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