Steam phase change heating furnace

Abstract

This invention relates to the field of steam phase change heating furnace technology, specifically to a steam phase change heating furnace. It comprises several air pumps installed at the top of the steam chamber of a cylindrical shell, with the pump outlets connected to jet nozzles located above the heat exchange tube bundle and facing the top wall of the tube bundle. The air pump inlets are connected to the lower part of the steam chamber via air pipes. Each tube of the heat exchange tube bundle has several fan-shaped liquid guide plates evenly arranged on its upper half-circumference, and several V-shaped flow guide grooves evenly arranged on its lower half-circumference. The upper V-shaped ends of the flow guide grooves are seamlessly connected to the lower fan-shaped ends of the liquid guide plates. Several ultrasonic transducers are arranged at intervals below the heat exchange tube bundle, forming a ring array evenly distributed along the entire circumference of the heat exchange tube bundle. The ultrasonic transducers do not contact the heat exchange tube bundle. This invention solves the technical problem of achieving full-circumferential liquid film destruction of the heat exchange tubes without damaging the heat exchange tube structure or interfering with normal steam replenishment.

Description

Technical Field

[0001] This invention relates to the field of steam phase change heating furnace technology, and more specifically, to a steam phase change heating furnace. Background Technology

[0002] Steam phase change heaters are mainstream oil and gas heating equipment widely used in oil and gas extraction and transportation. They utilize the vapor-liquid phase change of water to release the latent heat of vaporization, thereby indirectly heating viscous petroleum raw materials in pipelines. Because the extracted crude oil and natural gas have high concentrations and high viscosity, they are prone to blockages in pipeline transportation due to excessive viscosity. Therefore, using a steam phase change heater can generate high-temperature steam to exchange heat indirectly with crude oil, natural gas, and other media through contact, without heating the transportation pipeline with an open flame. This reduces the adhesion and waxing of crude oil caused by uneven heating, ensuring smooth transportation.

[0003] However, in the long-term operation environment, the high-temperature steam generated in the existing steam phase change heater will condense into a continuous liquid film after heat exchange on the outer wall of the heat exchange tube. The temperature of the liquid film drops after heat exchange, but it will not detach from the heat exchange tube, thus forming a thermal resistance layer at the heat exchange tube, which becomes the biggest obstacle to the heat transfer efficiency of the heater.

[0004] Some heating furnaces use ultrasonic transducers to drive the heat exchange tube bundle to vibrate as a whole to break the liquid film and scale on the tubes. However, under long-term mechanical vibration, the heat exchange tube bundle will experience metal fatigue, affecting its structural integrity and making it prone to major safety accidents such as cracking and oil leakage.

[0005] Another type of heating furnace also uses jet tubes to spray airflow to impact the tube wall and break the water film, in order to reduce the impact of vibration on the heat exchange tube bundle. However, in practical applications, the tube diameter of heat exchange tube bundles for media such as crude oil and natural gas is relatively large, and the coverage of a single jet is limited. If multiple jets are set to completely cover the tube wall, the multi-angle, high-velocity jets will generate turbulent airflow, which will hinder the normal flow of steam rising from the bottom water cavity and form an airflow barrier in the steam cavity. This will prevent the steam environment temperature from being replenished in time, thus affecting the heat exchange efficiency of the heating furnace. Summary of the Invention

[0006] The purpose of this application is to provide a steam phase change heater that solves the technical problem of destroying the liquid film in the entire circumference of the heat exchange tube without damaging the heat exchange tube structure or interfering with the normal steam rise and replenishment.

[0007] To solve the above-mentioned technical problems, the solution adopted in this application is as follows:

[0008] A steam phase change heating furnace includes a hollow cylinder, with a steam chamber in the upper part and a water chamber in the lower part. A heat exchange tube bundle is installed in the steam chamber, and a medium and a combustion tube are filled in the water chamber, with the medium immersing the combustion tube.

[0009] Several air pumps are installed at the top of the steam chamber. The air pump outlets are connected to the jet nozzles, which are located above the heat exchange tube bundle and face the top wall of the heat exchange tube bundle. The air pump inlets are connected to the lower part of the steam chamber through air pipes.

[0010] The upper half of the wall of each pipe in the heat exchange tube bundle is evenly arranged with several fan-shaped liquid guide plates, and the lower half of the wall of each pipe is evenly arranged with several V-shaped flow guide grooves. The number of flow guide grooves corresponds one-to-one with the number of liquid guide plates, and the upper V-shaped end of the flow guide groove is seamlessly connected to the lower fan-shaped end of the liquid guide plate.

[0011] Several ultrasonic transducers are arranged at intervals below the heat exchange tube bundle, and the ultrasonic transducers are evenly distributed in a ring array along the circumference of the entire heat exchange tube bundle.

[0012] The ultrasonic transducer does not come into contact with the heat exchange tube bundle.

[0013] Each tube of the heat exchange tube bundle has multiple jet nozzles evenly arranged at its top, and the angle between the jet nozzles and the length direction of the heat exchange tube bundle is greater than 0° and not greater than 90°.

[0014] The surface of the liquid guide plate is coated with a hydrophobic coating.

[0015] The liquid guide plate and the heat exchange tube bundle are set at an angle, and the jet nozzle sprays towards the surface of the maximum angle between the liquid guide plate and the heat exchange tube bundle.

[0016] The inlet of the air pump is connected to the lower part of the steam chamber, and the medium inside the air pump is high-temperature saturated steam.

[0017] The heat exchange tube bundle includes one or more pipes, each pipe being straight or bent.

[0018] The ultrasonic transducer is fixed to the inner wall of the cylinder, and the transducer end faces the lower half of the heat exchange tube bundle.

[0019] The technical solution of this application has at least the following advantages and beneficial effects:

[0020] To address the issue of thermal resistance caused by the formation of a low-temperature water film on the outside of the heat exchanger tube bundle in traditional steam heaters, this invention employs a single-point steam jet impact at the top of the heat exchanger tube bundle. This disrupts the liquid film on the upper half of the tube, ensuring the jet only acts on the top of the tube, reducing flow field turbulence caused by multi-angle, multi-point jets within the steam cavity. Furthermore, fan-shaped guide plates and V-shaped guide channels are sequentially installed on the upper and lower half of the tube to quickly collect and drip the dispersed liquid droplets. A ring-shaped ultrasonic transducer array is also installed at the bottom of the heat exchanger tube bundle. This generates an acoustic flow effect, causing the steam to form a ring-shaped circulating flow. The simultaneous impact of steam bubble collapse and the convergence of micro-liquid droplets on the lower half of the tube simultaneously disrupts the residual liquid film, achieving full-circumferential liquid film disruption and maintaining the heating efficiency of the entire heat exchanger tube bundle within the heater. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] Figure 2 This is a cross-sectional structural diagram of the present invention.

[0023] Figure 3 For the present invention Figure 2 A magnified structural diagram of A in the diagram.

[0024] Figure 4 This is a top view of the structure of the present invention after the cylinder body has been disassembled.

[0025] In the diagram: 1-Cylinder, 2-Water pump assembly, 201-Water pipe, 202-Water pump, 3-Media valve pipe, 301-Air inlet pipe, 302-Air outlet pipe, 4-Burner, 5-Combustion pipe, 6-Air pump, 7-Air jet nozzle, 8-Flue gas pipe, 801-Flue gas passage, 9-Liquid guide plate, 10-Flow guide groove, 11-Heat exchange tube bundle, 12-Ultrasonic transducer. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. The terms "center," "upper," "lower," "inner," and "outer," indicating orientation or positional relationships based on the orientation or positional relationships shown in the figures, or the orientation or positional relationships commonly used when the product is in use, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as a limitation on this application. It should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] Example

[0029] Please refer to Figures 1-4 This embodiment provides a steam phase change heater for heating and reducing the viscosity of crude oil during the gathering and transportation process in oil and gas fields. It includes a hollow cylinder 1. The hollow interior of the cylinder 1 includes an upper steam chamber and a lower water chamber. The volume of the water chamber accounts for at least half of the total volume of the cylinder.

[0030] A water pump assembly 2 is fixed on the cylinder 1. The water pump assembly 2 includes a water pump 202 and a water pipe 201. One end of the water pipe 201 is connected to the water cavity at the bottom of the cylinder 1. The water pump 202 is fixedly connected to the water pipe 201. The other end of the water pipe 201 is connected to an external water tank. After the water pump 202 is started, the water pipe 201 injects water medium into the cylinder 1 as a phase change medium.

[0031] A heat exchange tube bundle 11 is fixedly installed at the top of the steam chamber inside the cylinder 1. The two ends of the heat exchange tube bundle 11 are respectively connected to the external medium valve pipe 3. The medium valve pipe 3 includes an inlet pipe 301 and an outlet pipe 302. The inlet pipe 301 is connected to the conduction start end of the heat exchange tube bundle 11, and the outlet pipe 302 is connected to the conduction end end of the heat exchange tube bundle 11. It is used to input the crude oil waiting to be heated medium into the heat exchange tube bundle 11, and then leave the cylinder 1 from the outlet pipe 302 to end the heating.

[0032] A combustion tube 5 is horizontally fixedly installed in the lower part of the water chamber inside the cylinder 1. The combustion tube 5 is immersed in the water medium in the water chamber. One end of the combustion tube 5 extends out of the cylinder 1 and is fixedly connected to the burner 4. The burner 4 uses natural gas as fuel and can ignite the natural gas to burn inside the combustion tube 5, heating the combustion tube 5. The other end of the combustion tube 5 is connected to the flue gas pipe 8. The end of the flue gas pipe 8 is fixedly connected to the flue gas passage 801. The flue gas passage 801 is connected to the external environment and is used to discharge the flue gas generated by the combustion of natural gas.

[0033] The heating principle of the entire steam phase change heater is as follows: water medium is injected into the water chamber, immersing the combustion tube 5 at the bottom of the cylinder 1, the burner 4 is started, the combustion tube 5 heats up and transfers heat to the water chamber, the water medium gradually heats up and vaporizes, generating a large amount of steam, the steam rises and fills the steam chamber at the top of the cylinder 1, the high temperature steam contacts the heat exchange tube bundle 11, and heats the crude oil waiting to be heated medium in the heat exchange tube bundle 11 through heat conduction.

[0034] However, when using the steam phase change heater described above, after the steam comes into contact with the tube wall of the heat exchange tube bundle 11, it will condense rapidly due to heat exchange, and the steam will condense into droplets that adhere to the tube wall. When the droplets reach a certain amount, they will connect with each other on the tube wall, thereby forming a continuous liquid water film. The temperature of this liquid water film is lower than that of the steam, and it will also prevent the high-temperature steam from contacting the heat exchange tube bundle 11, thereby forming thermal resistance and reducing the heat exchange efficiency of the entire heater.

[0035] Although some equipment uses ultrasonic transducers to vibrate the entire heat exchange tube bundle 11 to break the liquid film and scale and shake off low-temperature liquid droplets, the heat exchange tube bundle 11 will experience metal fatigue under long-term mechanical vibration, affecting its structural tightness and making it prone to cracking and oil leakage.

[0036] To overcome the above problems, some equipment replaces the ultrasonic transducer with a jet tube, using the jet tube to spray a jet onto the tube wall to break the water film. However, in practical applications, the diameter of the heat exchange tube bundle 11 for media such as crude oil and natural gas is relatively large (if the diameter is too small, the already viscous crude oil will be more prone to blockage). The coverage of a single jet is limited. Moreover, if multiple jets are set to completely cover the tube wall, the disturbance of the multi-angle and high-height jets will cause turbulent airflow, which will hinder the flow of steam rising from the bottom water cavity. This will form an airflow layer in the steam cavity, and the ambient temperature of the steam cavity cannot be replenished in time, affecting the heat exchange efficiency.

[0037] To solve the above problems, please refer to Figure 2 and Figure 3In this embodiment, several air pumps 6 are fixedly installed at the top of the steam chamber. The outlet of the air pump 6 is fixedly connected to the jet nozzle 7. The jet nozzle 7 is located above the heat exchange tube bundle 11 and faces the top tube wall of the heat exchange tube bundle 11. The inlet of the air pump 6 is connected to the lower part of the steam chamber through an air pipe. It is used to draw high-temperature saturated steam that has just risen from the water chamber at the bottom of the cylinder 1 as a jet medium and spray it to the top of the steam chamber to break the water film on the tube wall of the heat exchange tube bundle 11.

[0038] In this heat exchange tube bundle 11, multiple jet nozzles 7 are evenly arranged at the top of each tube, and the angle between the jet nozzles 7 and the length direction of the heat exchange tube bundle 11 is greater than 0° and not greater than 90°.

[0039] It is worth noting that the heat exchange tube bundle 11 includes one or more pipes, and each pipe is straight or bent, which facilitates increasing the contact area between the pipes inside the heat exchange tube bundle 11 and the steam chamber space, thereby increasing the heat exchange efficiency.

[0040] Furthermore, in order to reduce the turbulence of the jet at the top of the heat exchange tube bundle 11 on the airflow in the steam chamber and to reduce the liquid film on the tube wall of the heat exchange tube bundle 11, several uniformly arranged fan-shaped liquid guide plates 9 are fixedly installed on the upper half of the tube wall of each pipe of the heat exchange tube bundle 11. The surface of the liquid guide plate 9 is coated with a hydrophobic coating. Several uniformly arranged V-shaped flow guide grooves 10 are opened on the lower half of the tube wall of each pipe. The upper V-shaped end of the flow guide groove 10 is seamlessly connected to the lower fan-shaped end of the liquid guide plate 9, thereby guiding the liquid droplets intercepted and guided on the liquid guide plate 9 into the flow guide groove 10, so that the liquid droplets are guided to flow into the bottom V-shaped end of the flow guide groove 10 and converge into larger liquid droplets.

[0041] There is also an angle between the liquid guide plate 9 and the heat exchange tube bundle 11, and the jet nozzle 7 sprays towards the surface of the larger angle between the liquid guide plate 9 and the heat exchange tube bundle 11.

[0042] Preferably, when the heating furnace is working, the water chamber begins to generate high-temperature steam to heat the heat exchange tube bundle 11. After a period of time, when a water film begins to form, the air pump 6 is started. The jet nozzle 7 at the top of the heat exchange tube bundle 11 pumps in high-temperature saturated steam to impact the top of the heat exchange tube bundle 11. The kinetic energy of the jet instantly breaks the continuous condensate film formed on the top of the tube wall and blows the liquid droplets to both sides. The scattered droplets are captured by the fan-shaped guide plate located on the upper half of the tube wall and flow rapidly down the tube wall along its inclined hydrophobic guide surface. Then, they flow into the V-shaped guide groove 10 on the lower half of the tube wall and converge. Finally, they fall into the water chamber below by gravity.

[0043] Furthermore, in order to further disrupt the condensate film on the lower half of each pipe of the heat exchange tube bundle 11, in this embodiment, a number of ultrasonic transducers 12 are arranged at intervals below the heat exchange tube bundle 11. The ultrasonic transducers 12 are fixed on the cylinder wall and are evenly distributed along the entire circumference of the heat exchange tube bundle 11 to form a ring array, wherein none of the ultrasonic transducers 12 are in contact with the heat exchange tube bundle 11.

[0044] Preferably, when the jet nozzle 7 is jetting, the ultrasonic transducer 12 is activated. The high-frequency sound field generated by several ultrasonic transducers 12 forms an annular steam circulation flow along the circumference of the heat exchange tube bundle 11 between the lower half of the outer wall of each pipe of the heat exchange tube bundle 11 through the acoustic flow effect. On the one hand, the steam flow will generate some continuously collapsing steam bubbles due to the ultrasonic action, and use the collapse of steam bubbles to impact the water film on the tube wall. On the other hand, some steam will converge into larger micro steam droplets in the annular motion (larger droplets will escape the acoustic flow effect by gravity and fall directly into the water cavity below). These micro droplets will also break through the liquid film on the tube wall under high speed, thereby destroying the liquid water film on the lower half of the tube wall, allowing the high-temperature steam in the steam cavity to contact the heat exchange tube bundle 11 for heat conduction.

[0045] Preferably, in this embodiment, by setting a unidirectional jet only at the top of the heat exchange tube bundle 11, the jet splashing will basically only be located above the heat exchange tube bundle 11, reducing the flow field turbulence caused by multi-angle jets, maintaining the replacement and replenishment of steam at the heat exchange tube bundle 11 by the high-temperature steam in the bottom water cavity, maintaining heat exchange efficiency, and by setting a fan-shaped guide plate on the upper half of the tube wall, the impacted liquid droplets are quickly guided to the V-shaped guide groove 10 on the lower half of the tube wall for dripping and discharge, reducing the top of the tube wall After the liquid film impacts, the liquid droplets re-aggregate in the lower part of the tube wall to form a thicker liquid film. In addition, an annular transducer array is set at the bottom of the heat exchange tube bundle 11, and the transducers are not in contact with the heat exchange tube bundle 11. This prevents the heat exchange tube bundle 11 from generating structural vibrations. At the same time, the annular steam flow impacts the liquid film on the lower half of the tube wall, continuing to break the remaining liquid film on the tube wall, maintaining the overall heat exchange efficiency of the heat exchange tube bundle 11, and maintaining the structural strength and long-term safe use of the heat exchange tube bundle 11 in the heating furnace.

[0046] The various embodiments of the present invention have now been described in detail. To avoid obscuring the concept of the invention, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions of this invention based on the above description, and the scope of the invention is defined by the appended claims.

Claims

1. A steam phase change heating furnace, comprising a hollow cylinder (1), the upper part of which is configured as a steam chamber and the lower part as a water chamber, a heat exchange tube bundle (11) installed in the steam chamber, and a medium and a combustion tube (5) filled in the water chamber, wherein the medium immerses the combustion tube (5), characterized in that: The top of the steam chamber is provided with several air pumps (6), the outlet of the air pumps (6) is connected to the jet nozzle (7), the jet nozzle (7) is located above the heat exchange tube bundle (11), and the jet nozzle (7) faces the top tube wall of the heat exchange tube bundle (11). The inlet of the air pumps (6) is connected to the lower part of the steam chamber through the air pipe. The upper half of the tube wall of each pipe of the heat exchange tube bundle (11) is evenly arranged with several fan-shaped liquid guide plates (9), and the lower half of the tube wall of each pipe is evenly arranged with several V-shaped flow guide grooves (10). The number of flow guide grooves (10) corresponds one-to-one with the number of liquid guide plates (9). The upper V-shaped end of the flow guide groove (10) is seamlessly connected to the lower fan-shaped end of the liquid guide plate (9). Several ultrasonic transducers (12) are arranged at intervals below the heat exchange tube bundle (11). Several ultrasonic transducers (12) are fixed on the inner wall of the cylinder (1). Several ultrasonic transducers (12) are arranged to form a ring array evenly distributed circumferentially along the inner wall of the cylinder 1 below the entire heat exchange tube bundle (11). The ultrasonic transducer (12) does not contact the heat exchange tube bundle (11).

2. A steam phase change heating furnace according to claim 1, wherein Each tube of the heat exchange tube bundle (11) has multiple jet nozzles (7) evenly arranged at the top of each tube. The angle between the jet nozzles (7) and the length direction of the heat exchange tube bundle (11) is greater than 0° and not greater than 90°.

3. A steam phase change heating furnace according to claim 1, wherein The surface of the liquid guide plate (9) is coated with a hydrophobic coating.

4. A steam phase-change heating furnace according to claim 1, wherein The liquid guide plate (9) is set at an angle to the pipe of the heat exchange tube bundle (11), and the jet nozzle (7) sprays towards the surface of the maximum angle between the liquid guide plate (9) and the heat exchange tube bundle (11).

5. A steam phase change heating furnace according to claim 1, wherein The inlet of the air pump (6) is connected to the lower part of the steam chamber, and the medium inside the air pump (6) is saturated steam.

6. A steam phase-change heating furnace according to claim 1, wherein The heat exchange tube bundle (11) includes one or more tubes, each tube being straight or bent.

7. A steam phase-change heating furnace according to claim 1, wherein The transducer end of the ultrasonic transducer (12) is oriented toward the lower half of the heat exchange tube bundle (11).

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