Multi-heat source integrated cascade heat exchanger for pipeline crude oil system

Abstract

The application discloses a multi-heat source integrated cascade heat exchanger of a pipe transportation crude oil system and belongs to the technical field of heat exchange equipment. The heat exchanger solves the problem that the heat exchange equipment in the prior art cannot efficiently and integrally utilize multiple waste heat and is difficult to adapt to variable working conditions. The heat exchanger comprises a shell, heat exchange pipes penetrating through the shell and at least one movable floating barrier arranged in the shell. The floating barrier separates the shell into multiple independent heat exchange cavities such as a low-temperature heat exchange cavity and a medium-temperature heat exchange cavity, and each cavity can be connected with a heat medium of different grade. The floating barrier can automatically move under the action of the pressure difference between two heat exchange cavities or be manually adjusted and fixed through a driving rod connected with the floating barrier and an external locker, so that the volume of each heat exchange cavity is dynamically changed and the heat exchange area distribution is optimized. The heat exchanger has compact structure, can realize deep waste heat recovery according to the change of working conditions, has remarkable energy-saving effect and is suitable for the fields of petroleum chemical industry and the like.

Description

Technical Field

[0001] This invention belongs to the field of heat exchange equipment technology, and particularly relates to a high-efficiency and energy-saving heat exchanger that can integrate multiple heat sources and achieve cascade heat exchange for use in petrochemicals, especially in pipeline crude oil transportation systems. Background Technology

[0002] In the gathering, processing, and long-distance pipeline transportation of crude oil, heating is typically required to reduce the viscosity of high-pour-point, high-viscosity crude oil and decrease transportation friction. Existing heating methods often employ fire-tube furnaces or conventional heat exchangers using a single heat source, which suffer from high energy consumption, low thermal efficiency, and inability to fully utilize various waste heat resources of different grades within the system. For example, the waste heat from the cooling water of large pump units in oil pumping stations and the waste heat from high-temperature produced water discharged after treatment at combined stations are often directly discharged, resulting in significant energy waste.

[0003] Furthermore, the operating conditions of oil transportation systems vary with different seasons and throughputs, causing fluctuations in the flow rate of available waste heat sources. Traditional stationary heat exchange equipment struggles to adapt to these changing conditions and cannot consistently maintain optimal heat exchange efficiency, thus limiting energy-saving effects.

[0004] Therefore, there is an urgent need for a heat exchange device that can integrate multiple waste heat sources into one unit and dynamically adjust the heat exchange area according to changes in operating conditions, so as to achieve deep waste heat recovery and efficient cascade utilization. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-heat source integrated cascade heat exchanger for pipeline crude oil systems. This heat exchanger integrates multiple stages of heat exchange into one unit and, by setting a movable floating baffle, realizes dynamic adjustment of the volume of different heat exchange chambers under varying operating conditions, thereby maximizing the recovery and utilization of multi-grade waste heat in the system, achieving significant energy-saving effects and system flexibility.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An integrated multi-heat-source cascade heat exchanger for a pipeline crude oil system includes: a shell, wherein at least two mutually isolated heat exchange chambers are sequentially separated along its axial direction, namely a low-temperature heat exchange chamber and a medium-temperature heat exchange chamber, each heat exchange chamber having an independent heat medium inlet and a heat medium outlet; a tube bundle, including multiple heat exchange tubes penetrating the low-temperature heat exchange chamber and the medium-temperature heat exchange chamber; and at least one floating barrier, wherein the floating barrier is disposed between adjacent heat exchange chambers to separate the adjacent heat exchange chambers from each other; the floating barrier is slidably disposed within the shell, and a sealing structure for achieving dynamic sealing is provided at the sliding fit, so that the floating barrier can move along the axial direction of the shell under the action of the pressure difference between adjacent heat exchange chambers or under the action of the external force applied by the driving and locking device, thereby changing the relative volume of adjacent heat exchange chambers.

[0008] The sealing structure includes a first sealing structure and a second sealing structure. The first sealing structure is disposed on the outer periphery of the floating barrier to achieve dynamic sealing of the outer periphery of the floating barrier. The floating barrier is provided with multiple through holes corresponding to the heat exchange tubes. The second sealing structure is disposed at each through hole to form a dynamic seal between the floating barrier and the heat exchange tubes passing through it.

[0009] Preferably, the first sealing structure includes a sealing ring (such as a Gladley ring) disposed on the outer periphery of the floating barrier, and an expansion ring provided on the inner side of the sealing ring for providing initial preload. To ensure smooth movement of the floating barrier and to withstand radial forces, a wear-resistant support ring is also provided on its outer periphery.

[0010] Preferably, the second sealing structure includes a sealing sleeve fixed in the through hole, and the sealing sleeve is provided with at least one inner sealing ring for sealing the heat exchange tube. This modular design facilitates installation and maintenance.

[0011] Furthermore, a high-temperature heat exchange chamber is separated within the shell, which can utilize an actively heated high-temperature heat medium. The high-temperature heat exchange chamber is separated from the medium-temperature heat exchange chamber by another floating barrier.

[0012] Preferably, the floating barrier is a heat-insulating structure comprising: two floating plates arranged axially opposite each other; and a low thermal conductivity connecting sleeve that connects the two floating plates and forms a closed cavity between them. This cavity is used to reduce or block heat conduction between adjacent heat exchange chambers through the partition, ensuring the efficiency of the cascade heat exchange.

[0013] Preferably, to address the issue of poor roundness in conventional housing machining, a precision-machined sliding sleeve is fixed to the inner wall of the housing. The floating barrier slides along the inner wall of the sliding sleeve, ensuring smooth movement and reliable sealing. Limiting structures are provided at both ends of the sliding sleeve to restrict the movement range of the floating barrier.

[0014] Preferably, the driving and locking device of the present invention enables the floating barrier to move automatically not only by relying on the pressure difference between the two heat exchange chambers, but also to achieve manual intervention. The device includes: a driving rod, one end of which is connected to the floating barrier and the other end of which extends out of the housing; and a locking device disposed outside the housing for clamping and fixing or releasing the driving rod.

[0015] Preferably, the locking device has a simple and reliable structure, including a rotatable handwheel and a movable spindle. Rotating the handwheel allows the spindle to be axially fed or retracted, thereby pressing or releasing the drive rod.

[0016] The heat exchanger of the present invention further includes two tube sheets respectively fixed to both ends of the shell, and the two ends of the heat exchange tube are respectively fixed to the two tube sheets; the two ends of the shell are closed by end caps, one end cap having a tube inlet and the other end cap having a tube outlet.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. High integration and significant energy saving: Multi-stage heat exchange is integrated into one device, realizing the cascade preheating of pipeline crude oil, and using the waste heat of different grades in the most suitable temperature zone, which greatly reduces the consumption of primary energy and has a significant energy saving effect.

[0019] 2. Dynamic adaptation and efficient operation: Through movable floating baffles, the heat exchanger can automatically or manually adjust the volume (i.e. heat exchange area) of each heat exchange chamber according to the change of heat medium flow, so that the equipment always operates in the optimal heat exchange state, solving the problem of poor adaptability to changing operating conditions.

[0020] 3. Compact structure and reduced cost: One device replaces multiple heat exchangers and their complex piping connections, greatly reducing equipment footprint, piping investment and installation and maintenance costs.

[0021] 4. Safe and reliable, flexible operation: Equipped with manual drive and locking devices, providing a means of manual intervention to ensure reliable control of the equipment under various conditions and high operational flexibility. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 This is a three-dimensional structural cross-sectional view of the present invention;

[0024] Figure 3 yes Figure 2 A magnified view of part A in the middle;

[0025] Figure 4 yes Figure 2 A magnified view of part B in the middle;

[0026] Figure 5 This is a planar structural sectional view of the present invention;

[0027] Figure 6 yes Figure 5 A magnified view of part C in the middle;

[0028] Figure 7 yes Figure 5 A magnified view of part D in the middle;

[0029] Figure 8 This is a schematic diagram of the floating barrier.

[0030] In the diagram: 1. Shell; 2. Head; 3. Tube-side inlet; 4. Tube-side outlet; 5. Low-temperature heat exchange chamber; 6. Medium-temperature heat exchange chamber; 7. High-temperature heat exchange chamber; 8. Heat medium inlet; 9. Heat medium outlet; 10. Drive rod; 11. Locking device; 111. Mandrel; 12. Floating baffle; 121. Float plate; 122. Low thermal conductivity connecting sleeve; 123. Support ring; 124. Expansion ring; 125. Sealing ring; 126. Sealing sleeve; 127. Inner sealing ring; 128. Cavity; 13. Tube sheet; 14. Heat exchange tube; 15. Baffle plate; 16. Sliding sleeve. Detailed Implementation

[0031] The present invention will be further described below with reference to specific embodiments.

[0032] The description of the present invention is merely a structural or even functional description of the embodiments, and the scope of the present invention is not limited by the embodiments described herein.

[0033] like Figures 1-8 As shown, this embodiment is achieved through the following technical solution:

[0034] This invention provides a multi-heat-source integrated cascade heat exchanger for a pipeline crude oil system, comprising a cylindrical shell 1, with end caps 2 connected to both ends of the shell 1 via flanges or similar means. Two tube sheets 13 are respectively fixed to both ends of the shell 1, and multiple heat exchange tubes 14 penetrate the shell 1, with their ends fixed to the two tube sheets 13 by expansion joints or welding. The crude oil to be heated, as the tube-side fluid, enters from the tube-side inlet 3 on one end cap 2, flows through the heat exchange tubes 14, and exits from the tube-side outlet 4 on the other end cap 2.

[0035] The shell-side space inside the shell 1 is divided axially into multiple independent heat exchange chambers. In this embodiment, it is divided into a low-temperature heat exchange chamber 5, a medium-temperature heat exchange chamber 6, and a high-temperature heat exchange chamber 7. Adjacent heat exchange chambers are dynamically sealed and separated by a floating barrier 12. Each heat exchange chamber is equipped with an independent heat medium inlet 8 and heat medium outlet 9 for connecting heat medium fluids of different temperatures and grades. For example, the low-temperature heat exchange chamber 5 can connect to waste heat from pump cooling water, the medium-temperature heat exchange chamber 6 can connect to waste heat from produced water, and the high-temperature heat exchange chamber 7 can connect to boiler hot water. The heat medium exchanges heat countercurrently with the crude oil flowing through the heat exchange tube 14 within its respective chamber. Baffles 15 can be installed inside the shell cavity to enhance heat transfer on the shell side.

[0036] like Figure 8 As shown, the floating barrier 12 consists of two mating floats 121 connected by a low thermal conductivity connecting sleeve 122, forming an internal cavity 128. The air layer inside this cavity acts as insulation, preventing heat "short circuit" between adjacent high and low temperature chambers.

[0037] To achieve dynamic sealing, the floating barrier 12 has a sealing structure on its outer periphery. A wear-resistant support ring 123 is installed on its outer ring to support the weight of the floating barrier 12 and ensure its centering within the housing. A high-performance sealing ring 125 (such as a polytetrafluoroethylene Glycol ring) is also installed on the outer periphery of the floating barrier 12. An expansion ring 124 made of rubber is provided on the inner side of the sealing ring 125 to provide initial preload and ensure a good sealing effect.

[0038] Since multiple heat exchange tubes 14 need to pass through the floating baffle 12, an independent sealing structure is provided at each tube penetration hole of the floating baffle 12. A sealing sleeve 126 is fixed in each hole. The sleeve has an annular groove machined inside, and multiple inner sealing rings 127 (such as O-rings or U-rings) are installed in the groove to tightly hold the outer wall of the heat exchange tube 14 and prevent the shell-side heat medium from leaking at the gap between the tube wall and the baffle.

[0039] To ensure smooth movement of the floating barrier 12, a precision-machined sliding sleeve 16 is fixedly installed on the inner wall of the housing 1. The sliding sleeve 16 has a smooth inner surface and precise roundness, and the support ring 123 and sealing ring 125 on the outer periphery of the floating barrier 12 slide in cooperation with the inner wall of this sliding sleeve 16. Limiting structures are provided at both ends of the sliding sleeve 16, and the length of the sliding sleeve 16 determines the movable range of the floating barrier 12.

[0040] The floating barrier 12 of the present invention has both automatic and manual movement modes. The floating barrier 12 is connected by a drive rod 10, which extends out of the housing through the end cap 2. The seal between the drive rod 10 and the end cap 2 is a packing seal. A locking device 11 is provided on the outside of the housing.

[0041] During operation, the locking device 11 can be loosened, at which point the floating barrier 12 can move automatically under the pressure difference between the two heat exchange chambers. For example, when the flow rate of the heat medium on one side increases, causing the pressure to rise, the floating barrier 12 will automatically move to the side with lower pressure, thereby increasing the chamber volume on the high-pressure side and making the heat exchange area distribution more reasonable.

[0042] The operator can also manually adjust the position of the floating barrier 12 by pushing and pulling the drive rod 10. After adjustment, tighten the locking device 11. In this embodiment, the locking device 11 is structured as follows: by rotating the handwheel, the spindle 111 is driven to move axially, and the end of the spindle 111 can be pressed against the surface of the drive rod 10, and it is firmly positioned by friction.

[0043] In summary, this invention, through its ingenious structural design, integrates multi-stage heat exchange, dynamic adaptation, and manual intervention into a single system, forming a highly efficient, flexible, and compact deep waste heat recovery system, which is particularly suitable for pipeline crude oil systems with variable operating conditions.

[0044] Of course, the above description is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the embodiments of the present invention. The present invention is also not limited to the above examples, and all equivalent changes and improvements made by those skilled in the art within the scope of the present invention should fall within the patent coverage of the present invention.

Claims

1. A multi-heat source integrated cascade heat exchanger for a pipeline crude oil system, characterized in that, include: The shell (1) is divided into at least two mutually isolated heat exchange chambers along its axial direction, namely a low temperature heat exchange chamber (5) and a medium temperature heat exchange chamber (6), and each heat exchange chamber is provided with an independent heat medium inlet (8) and heat medium outlet (9). The tube bundle includes multiple heat exchange tubes (14) that penetrate the low-temperature heat exchange chamber (5) and the medium-temperature heat exchange chamber (6). At least one floating barrier (12) is disposed between adjacent heat exchange chambers to separate adjacent heat exchange chambers from each other; the floating barrier (12) is slidably disposed in the housing (1) and a sealing structure for achieving dynamic sealing is provided at the sliding fit, so that the floating barrier (12) can move along the axial direction of the housing (1) under the action of the pressure difference between adjacent heat exchange chambers or under the action of the external force applied by the driving and locking device, so as to change the relative volume of adjacent heat exchange chambers; The sealing structure includes a first sealing structure and a second sealing structure. The first sealing structure is disposed on the outer periphery of the floating barrier (12) to achieve dynamic sealing of the outer periphery of the floating barrier (12). The floating barrier (12) is provided with a plurality of through holes corresponding to the heat exchange tube (14). The second sealing structure is disposed at each through hole to form a dynamic seal between the floating barrier (12) and the heat exchange tube (14) passing through it. The first sealing structure includes a sealing ring (125) disposed on the outer periphery of the floating barrier (12), and an expansion ring (124) for providing preload is provided on the inner side of the sealing ring (125). The outer periphery of the floating barrier (12) is also provided with a support ring (123) for bearing its weight and providing radial support. The second sealing structure includes a sealing sleeve (126) fixed in the through hole, and the sealing sleeve (126) is provided with at least one inner sealing ring (127) for sealing the heat exchange tube (14).

2. The multi-heat source integrated cascade heat exchanger for pipeline crude oil systems according to claim 1, characterized in that, The shell (1) is further divided into a high-temperature heat exchange chamber (7), which is separated from the medium-temperature heat exchange chamber (6) by another floating barrier (12).

3. The multi-heat source integrated cascade heat exchanger for pipeline crude oil systems according to claim 1 or 2, characterized in that, The floating barrier (12) is a heat insulation structure, which includes: Two floating plates (121) are arranged opposite each other along the axial direction. A low thermal conductivity connecting sleeve (122) is connected between two floats (121) and forms a closed cavity (128) between the two floats (121).

4. The multi-heat source integrated cascade heat exchanger for pipeline crude oil systems according to claim 1, characterized in that, The inner wall of the housing (1) is fixed with a sliding sleeve (16), the floating barrier (12) slides on the inner wall of the sliding sleeve (16), and the two ends of the sliding sleeve (16) are provided with limiting structures.

5. The multi-heat source integrated cascade heat exchanger for pipeline crude oil systems according to claim 1, characterized in that, The driving and locking device includes: A drive rod (10), one end of which is connected to a floating barrier (12), and the other end of which extends out of the housing (1). A locking device (11) is disposed outside the housing (1) and is used to clamp or release the drive rod (10).

6. The multi-heat source integrated cascade heat exchanger for pipeline crude oil systems according to claim 5, characterized in that, The locking device (11) includes a rotatable handwheel and a movable spindle (111). Rotating the handwheel allows the spindle (111) to move axially, thereby pressing or releasing the drive rod (10).

7. The multi-heat source integrated cascade heat exchanger for a pipeline crude oil system according to claim 1, characterized in that, It also includes two tube sheets (13) fixed to both ends of the shell (1), and the two ends of the heat exchange tube (14) are fixed on the two tube sheets (13); the two ends of the shell (1) are closed by end caps (2), one end cap (2) is provided with a tube inlet (3), and the other end cap (2) is provided with a tube outlet (4).

Images