Waste heat utilization device for LNG (Liquefied Natural Gas) internal combustion power-driven ship

Abstract

The invention provides a waste heat utilization device for an LNG (Liquefied Natural Gas) internal combustion power-driven ship. The waste heat utilization device comprises a heat exchange box, a first heat exchange tube and a second heat exchange tube are arranged in the heat exchange box; heat conduction liquid is filled in the heat exchange box; the first heat exchange pipe is rotationally connected to a cooling water pipeline of an engine in a sealed mode, and first heat exchange fin plates are arranged in the length direction of the first heat exchange pipe in an array mode. The second heat exchange pipe is rotationally connected to the fuel pipeline between the LNG storage tank and the engine in a sealed mode, and second heat exchange fin plates are arranged in the length direction of the second heat exchange pipe in an array mode; the first heat exchange fin plates and the second heat exchange fin plates are arranged in a staggered mode. The heat exchange speed control unit is configured to adjust the size of the axial projection overlapping area between the first heat exchange fin plate and the second heat exchange fin plate by controlling the first heat exchange pipe and the second heat exchange pipe to rotate. According to the device, when the output power of the LNG engine changes, the heat exchange speed from the cooling water pipeline to the fuel pipeline is rapidly adjusted, waste heat is reasonably utilized, and the energy-saving and emission-reducing effects of operation of the LNG internal combustion power-driven ship are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of waste heat utilization of LNG internal combustion powered ships, and in particular provides a waste heat utilization device for LNG internal combustion powered ships. Background Art

[0002] LNG fuel has received extensive attention and favor as a high-quality, efficient and economical clean energy. With the country's advocacy of clean energy and the continuous development and progress of technology, LNG internal combustion powered ships have gradually been promoted and used in inland and coastal shipping. During the operation of the ship's LNG internal combustion engine, the LNG fuel in the storage tank is supplied to the engine through valves and fuel pipelines, and is converted from liquid to gas due to the huge pressure difference. Under normal temperature conditions, there are tiny liquid LNG gases that are not completely vaporized in the fuel pipeline, which enter the LNG internal combustion engine in an unsaturated state, and the problem of incomplete fuel combustion is prone to occur, which not only affects the system efficiency and wastes fuel, but also the exhaust gas from incomplete combustion is discharged into the air, causing environmental pollution.

[0003] In order to solve the above problems, some LNG engines preheat the fuel pipeline with the heat of the engine cooling water through a heat exchanger to improve the LNG vaporization effect. However, after a lot of practice, it was found that the heat exchange rate of the current heat exchanger is fixed and cannot adapt to the working conditions of the engine's output power changes. Under heavy load conditions, the LNG storage tank supplies fuel to the engine through the fuel pipeline at a higher speed. Limited by the fixed heat exchange rate of the heat exchanger, the heat of the cooling water pipeline cannot be transferred to the fuel pipeline in time, and the preheating effect of the fuel pipeline is poor, which cannot solve the problem of insufficient LNG vaporization. At the same time, the heat of the cooling water cannot be quickly dissipated and is higher than the reasonable temperature, affecting the normal working state of the engine. Under light load conditions, the LNG storage tank supplies fuel to the engine through the fuel pipeline at a lower speed. Limited by the fixed heat exchange rate of the heat exchanger, the heat of the cooling water pipeline dissipates relatively too much heat to the fuel pipeline, causing heat waste, and also causing the cooling water to dissipate too much heat and be lower than the reasonable temperature, affecting the normal working state of the engine. Summary of the invention

[0004] Based on this, the present invention provides a waste heat utilization device for LNG internal combustion powered ships, in which a heat exchange box with adjustable heat exchange speed is arranged to quickly adjust the heat exchange speed from the cooling water pipeline to the fuel pipeline when the output power of the LNG engine changes, adapt to the change of LNG fuel supply speed, improve the vaporization rate of LNG in the fuel pipeline, and keep the water temperature of the cooling water within the set range, so as to reasonably utilize the waste heat and achieve the purpose of energy saving and emission reduction in the operation of LNG internal combustion powered ships.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A waste heat utilization device for an LNG internal combustion powered ship, comprising a heat exchange box and a heat exchange speed control unit;

[0007] The heat exchange box is provided with a first heat exchange tube and a second heat exchange tube which are parallel to each other and extend in the horizontal direction, the first heat exchange tube and the second heat exchange tube both pass through the side walls of the heat exchange box at both ends and are sealed and rotatably connected to the heat exchange box; the heat exchange box is filled with a heat transfer fluid;

[0008] The first heat exchange tube is sealed and rotatably connected to the cooling water pipeline of the engine, and a plurality of first heat exchange fins are arranged in an array on the surface of the tube body located in the heat exchange box along its length direction; the second heat exchange tube is sealed and rotatably connected to the fuel pipeline between the LNG storage tank and the engine, and a plurality of second heat exchange fins are arranged in an array on the surface of the tube body located in the heat exchange box along its length direction; the plurality of first heat exchange fins are arranged alternately with the plurality of second heat exchange fins;

[0009] The heat exchange speed control unit is configured to adjust the size of the axially projected overlapping area between the first heat exchange fin plate and the second heat exchange fin plate by controlling the rotation of the first heat exchange tube and the second heat exchange tube.

[0010] Furthermore, the first heat exchange fin and the second heat exchange fin are both circular plates, the first heat exchange tube passes through the first heat exchange fin and the axis of the first heat exchange tube is eccentrically arranged relative to the axis of the first heat exchange fin, and the second heat exchange tube passes through the second heat exchange fin and the axis of the second heat exchange tube is eccentrically arranged relative to the axis of the second heat exchange fin.

[0011] Furthermore, the heat exchange speed control unit includes a rotating mechanism capable of driving the first heat exchange tube to rotate and a constant speed transmission mechanism disposed between the first heat exchange tube and the second heat exchange tube. When the first heat exchange tube rotates, the constant speed transmission mechanism drives the second heat exchange tube to rotate circumferentially at a constant speed.

[0012] The eccentric direction of the axis of the first heat exchange tube relative to the axis of the first heat exchange fin plate and the eccentric direction of the axis of the second heat exchange tube relative to the axis of the second heat exchange fin plate are symmetrically arranged.

[0013] Furthermore, the heat exchange speed control unit drives the first heat exchange tube and the second heat exchange tube to rotate, and when the distance between the axes of the first heat exchange fin and the second heat exchange fin is the smallest, the second heat exchange fin is inserted between two adjacent first heat exchange fins, and the axial projection overlap area between the first heat exchange fin and the second heat exchange fin is the largest; when the distance between the axes of the first heat exchange fin and the second heat exchange fin is the largest, the axial projection overlap area between the first heat exchange fin and the second heat exchange fin is the smallest or there is no axial projection overlap area.

[0014] Furthermore, the first heat exchange tube is located directly above the second heat exchange tube; the heat transfer liquid level in the heat exchange box is higher than the first heat exchange tube, and when the axial projection overlap area between the first heat exchange fin and the second heat exchange fin is the smallest or has no axial projection overlap area, most of the portion of the first heat exchange fin located above the first heat exchange tube is exposed to the heat transfer liquid surface.

[0015] Furthermore, the constant speed transmission mechanism includes a driving gear and a driven gear with equal number of teeth and meshing with each other, the driving gear is connected to the first heat exchange tube, and the driven gear is connected to the second heat exchange tube; the rotating mechanism includes an adjusting motor and a belt transmission assembly, the driving pulley of the belt transmission assembly is connected to the motor shaft of the adjusting motor; the driven pulley of the belt transmission assembly is connected to the first heat exchange tube, the transmission belt is arranged between the driving pulley and the driven pulley, and the adjusting motor drives the first heat exchange tube to rotate through the belt transmission assembly.

[0016] Furthermore, a fuel flow monitor is provided on the fuel pipeline, and the fuel flow monitor is electrically connected to the heat exchange speed control unit;

[0017] The heat exchange speed control unit is configured to control the action of the rotating mechanism according to the monitoring value of the fuel flow monitor;

[0018] When the fuel flow value monitored by the fuel flow monitor increases, the heat exchange speed control unit is used to increase the axial projection overlap area between the first heat exchange fin and the second heat exchange fin. When the fuel flow monitoring value decreases, the heat exchange speed control unit is used to reduce the axial projection overlap area between the first heat exchange fin and the second heat exchange fin.

[0019] Furthermore, a fuel temperature monitor is provided on the fuel pipeline, and the fuel temperature monitor is electrically connected to the heat exchange speed control unit;

[0020] The heat exchange speed control unit is configured to control the action of the rotating mechanism according to the monitoring value of the fuel temperature monitor;

[0021] When the fuel temperature value monitored by the fuel temperature monitor decreases, the heat exchange speed control unit is used to increase the axial projection overlap area between the first heat exchange fin and the second heat exchange fin. When the fuel temperature monitoring value increases, the heat exchange speed control unit is used to reduce the axial projection overlap area within the first heat exchange fin and the second heat exchange fin bracket.

[0022] Furthermore, both ends of the first heat exchange tube are sealed and rotatably connected to the cooling water pipeline through a first rotary sealing mechanism, and both ends of the second heat exchange tube are sealed and rotatably connected to the fuel pipeline through a second rotary sealing mechanism.

[0023] Compared with the existing technology, the technical advantages of the LNG internal combustion powered ship waste heat utilization device provided are at least reflected in:

[0024] On the one hand, a heat exchange box is arranged between the engine and the LNG storage tank, including a first heat exchange tube sealed and rotatably connected to the cooling water pipeline, and a second heat exchange tube sealed and rotatably connected to the fuel pipeline. A first heat exchange fin is arranged on the first heat exchange tube, and a second heat exchange fin is arranged on the second heat exchange pipeline. The heat exchange speed control unit adjusts the size of the axial projection overlap area of ​​the two heat exchange fins by changing the relative position of the first heat exchange fin and the second heat exchange fin, dynamically changes the heat exchange speed, adapts to the changes in the output power working conditions of the engine, adapts to the changes in the LNG fuel supply speed, improves the LNG vaporization rate, and keeps the water temperature of the cooling water within the set range, so as to achieve energy saving and emission reduction effects during the operation of LNG internal combustion powered ships.

[0025] Secondly, the first heat exchange fin on the surface of the first heat exchange tube is eccentrically arranged, and the second heat exchange fin on the surface of the second heat exchange tube is eccentrically arranged. The first heat exchange tube and the second heat exchange tube are connected by a constant speed transmission mechanism. The eccentric directions of the two heat exchange fins are symmetrically arranged. The rotating mechanism drives the two heat exchange tubes to rotate at a constant speed to achieve the overlap adjustment of the axial projection area of ​​the heat exchange fins, thereby achieving the purpose of fast and stable adjustment of the heat exchange speed between the two heat exchange tubes.

[0026] Thirdly, a monitor for monitoring fuel flow and temperature is set in the fuel pipeline. The heat exchange speed control unit adjusts the axial projection overlapping area of ​​the first heat exchange fin and the second heat exchange fin according to the monitored fuel flow and temperature information, thereby accurately controlling the heat exchange speed between the two heat exchange tubes, improving the LNG vaporization rate and maintaining a reasonable water temperature for the cooling water, achieving a balanced operating condition of the engine, rationally utilizing waste heat, and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 This is a schematic structural diagram of the LNG internal combustion powered ship waste heat utilization device provided by the present invention;

[0029] Figure 2 It is a structural schematic diagram of the heat exchange box provided by the present invention;

[0030] Figure 3 A schematic diagram of the structure of the heat exchange box provided by the present invention after removing part of the box body;

[0031] Figure 4This is a control system block diagram of the LNG internal combustion powered ship waste heat utilization device provided by the present invention;

[0032] Figure 5 It is a schematic diagram of the state of the heat exchange box provided by the present invention being adjusted to a high-speed heat exchange state;

[0033] Figure 6 It is a schematic diagram of the state in which the first heat exchange tube and the second heat exchange tube of the present invention are adjusted to a high-speed heat exchange state;

[0034] Figure 7 It is a schematic diagram of the state in which the first heat exchange fin plate and the second heat exchange fin plate of the present invention are adjusted to a high-speed heat exchange state;

[0035] Figure 8 It is a schematic diagram of the state of the heat exchange box provided by the present invention being adjusted to a low-speed heat exchange state;

[0036] Fig. 9 It is a schematic diagram of the state in which the first heat exchange tube and the second heat exchange tube of the present invention are adjusted to a low-speed heat exchange state;

[0037] Fig.10 It is a schematic diagram of the state in which the first heat exchange fin plate and the second heat exchange fin plate of the present invention are adjusted to a low-speed heat exchange state.

[0038] Description of the accompanying drawings:

[0039] 1-heat exchange box, 11-first heat exchange tube, 12-first heat exchange fin plate, 13-first rotary sealing mechanism, 14-second heat exchange tube, 15-second heat exchange fin plate, 16-second rotary sealing mechanism;

[0040] 2-engine, 21-cooling water pipeline, 22-fuel pipeline;

[0041] 3-LNG storage tanks;

[0042] 4- heat exchange speed control unit, 41- rotation mechanism, 42- constant speed transmission mechanism, 43- fuel flow monitor, 44- fuel temperature monitor;

[0043] 5-Thermal fluid level.

[0044] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. DETAILED DESCRIPTION

[0045] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps and the composition of the materials set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0046] Embodiment 1:

[0047] A waste heat utilization device for LNG internal combustion powered ships, such as Figures 1 to 4 As shown, it includes a heat exchange box 1 and a heat exchange speed control unit 4;

[0048] The heat exchange box 1 is provided with a first heat exchange tube 11 and a second heat exchange tube 14 which are parallel to each other and extend in the horizontal direction. The first heat exchange tube 11 and the second heat exchange tube 14 both penetrate the side walls of the heat exchange box 1 at both ends and are sealed and rotatably connected to the heat exchange box 1. The heat exchange box 1 is filled with a heat transfer fluid.

[0049] The first heat exchange tube 11 is sealed and rotatably connected to the cooling water pipeline 21 of the engine 2, and a plurality of first heat exchange fins 12 are arranged in an array along the length direction on the surface of the tube body located in the heat exchange box 1; the second heat exchange tube 14 is sealed and rotatably connected to the fuel pipeline 22 between the LNG storage tank 3 and the engine 2, and a plurality of second heat exchange fins 15 are arranged in an array along the length direction on the surface of the tube body located in the heat exchange box 1; the plurality of first heat exchange fins 12 and the plurality of second heat exchange fins 15 are arranged alternately;

[0050] The heat exchange speed control unit 4 is configured to adjust the size of the axial projection overlap area between the first heat exchange fin plate 12 and the second heat exchange fin plate 15 by controlling the rotation of the first heat exchange tube 11 and the second heat exchange tube 14, that is, to adjust the heat exchange speed between the first heat exchange tube 11 and the second heat exchange tube 14. The first heat exchange fin plate 12 and the second heat exchange fin plate 15 perform heat exchange through the heat transfer fluid.

[0051] At present, the LNG engines of LNG internal combustion powered ships use heat from the engine cooling water to preheat the fuel pipeline through a heat exchanger. However, after extensive practice, it was found that the heat exchange rate of the heat exchanger is fixed and cannot adapt to the changing conditions of the engine's output power, thus affecting the normal working state of the engine.

[0052] Based on the LNG internal combustion powered ship waste heat utilization device provided in this embodiment, the heat exchange speed control unit dynamically changes the heat exchange speed between the two heat exchange tubes by changing the relative position of the first heat exchange fin 12 and the second heat exchange fin 15, adjusting the size of the axial projection overlap area between the first heat exchange fin 12 and the second heat exchange fin 15, so as to quickly adjust the heat exchange speed from the cooling water pipeline to the fuel pipeline, adapt to the change of the output power of the LNG engine, reasonably utilize the waste heat, and achieve the energy saving and emission reduction effect of the ship operation.

[0053] Specifically, when the operating condition is heavy load, the axial projection overlap area of ​​the first heat exchange fin 12 and the second heat exchange fin 15 is increased to improve the heat exchange rate; when the operating condition is light load, the axial projection overlap area of ​​the first heat exchange fin 12 and the second heat exchange fin 15 is reduced to reduce the heat exchange rate, thereby adapting to the changes in the output power of the engine and the changes in the operating conditions. It not only adapts to the changes in the LNG fuel supply speed and improves the LNG vaporization rate, but also keeps the water temperature of the cooling water within the set range, thereby realizing the rational use of waste heat and achieving the energy-saving and emission reduction effects of the operation of LNG internal combustion powered ships.

[0054] like Figures 5 to 10 As shown, in this embodiment, the first heat exchange fin plate 12 and the second heat exchange fin plate 15 are both circular plates, the first heat exchange tube 11 passes through the first heat exchange fin plate 12, and the axis of the first heat exchange tube 11 is eccentrically arranged relative to the axis of the first heat exchange fin plate 12, and the second heat exchange tube 14 passes through the second heat exchange fin plate 15, and the axis of the second heat exchange tube 14 is eccentrically arranged relative to the axis of the second heat exchange fin plate 15. In other embodiments, the heat exchange fin plate may also be an elliptical, oblate, etc. shape that is eccentrically arranged.

[0055] In this embodiment, the heat exchange speed control unit 4 includes a rotating mechanism 41 that can drive the first heat exchange tube 11 to rotate and a constant speed transmission mechanism 42 disposed between the first heat exchange tube 11 and the second heat exchange tube 14. When the first heat exchange tube 11 rotates, the constant speed transmission mechanism 42 drives the second heat exchange tube 14 to rotate in a constant speed circumferential direction.

[0056] The eccentric direction of the axis of the first heat exchange tube 11 relative to the axis of the first heat exchange fin plate 12 and the eccentric direction of the axis of the second heat exchange tube 14 relative to the axis of the second heat exchange fin plate 15 are symmetrically arranged. The two heat exchange fin plates are symmetrically arranged in the eccentric direction, and the rotating mechanism 41 drives the two heat exchange tubes to rotate at the same speed, so as to adjust the overlap size of the axial projection area of ​​the heat exchange fin plates, and realize the rapid and stable adjustment of the heat exchange speed between the two heat exchange tubes.

[0057] The heat exchange speed control unit 4 drives the first heat exchange tube 11 and the second heat exchange tube 14 to rotate. When the distance between the axes of the first heat exchange fin 12 and the second heat exchange fin 15 is the smallest, the second heat exchange fin 15 is inserted between two adjacent first heat exchange fins 12, and the axial projection overlap area between the first heat exchange fin 12 and the second heat exchange fin 15 is the largest. Through this arrangement, uniform heat exchange can be performed through each heat exchange fin to improve the heat exchange efficiency; when the distance between the axes of the first heat exchange fin 12 and the second heat exchange fin 15 is the largest, the axial projection overlap area between the first heat exchange fin 12 and the second heat exchange fin 15 is the smallest or there is no axial projection overlap area.

[0058] The first heat exchange tube 11 is located directly above the second heat exchange tube 14; the heat transfer liquid level 5 of the heat transfer liquid in the heat exchange box 1 is higher than the first heat exchange tube 11, and when the axial projection overlap area between the first heat exchange fin 12 and the second heat exchange fin 15 is the smallest or there is no axial projection overlap area, most of the portion of the first heat exchange fin 12 located above the first heat exchange tube 11 is exposed to the heat transfer liquid level 5.

[0059] Based on the above arrangement, the heat transfer liquid level 5 in the heat exchange box 1 is above the tube body of the first heat exchange tube 11. As the tube body of the first heat exchange tube 11 rotates, the volume of the first heat exchange fin 12 with an eccentric structure immersed in the heat transfer liquid changes, thereby changing the height of the heat transfer liquid level 5, so that the volume of the first heat exchange fin 12 exposed to the liquid surface changes, which not only changes the speed at which the first heat exchange fin 12 releases heat to the heat transfer liquid, but also indirectly changes the speed at which heat is conducted from the first heat exchange tube 11 to the second heat exchange tube 14.

[0060] The constant speed transmission mechanism 42 specifically includes a driving gear and a driven gear with equal number of teeth and meshing with each other, the driving gear is connected to the first heat exchange tube 11, and the driven gear is connected to the second heat exchange tube 14; the rotating mechanism 41 includes an adjusting motor and a belt transmission assembly, the driving pulley of the belt transmission assembly is connected to the motor shaft of the adjusting motor; the driven pulley of the belt transmission assembly is connected to the first heat exchange tube 11, the transmission belt is arranged between the driving pulley and the driven pulley, and the adjusting motor drives the first heat exchange tube 11 to rotate through the belt transmission assembly.

[0061] In this embodiment, both ends of the first heat exchange tube 11 are sealed and rotatably connected to the cooling water pipeline 21 through the first rotary sealing mechanism 13 , and both ends of the second heat exchange tube 14 are sealed and rotatably connected to the fuel pipeline 22 through the second rotary sealing mechanism 16 .

[0062] Embodiment 2:

[0063] like Figure 4 As shown, based on the LNG internal combustion powered ship waste heat utilization device of Example 1, a fuel flow monitor 43 and a fuel temperature monitor 44 connected to the heat exchange rate control unit 4 are provided.

[0064] Specifically, a fuel flow monitor 43 is provided on the fuel pipeline 22, and the fuel flow monitor 43 is electrically connected to the heat exchange speed control unit 4;

[0065] The heat exchange speed control unit 4 is configured to control the action of the rotating mechanism 41 according to the monitoring value of the fuel flow monitor 43;

[0066] When the fuel flow value monitored by the fuel flow monitor 43 increases, the axial projection overlap area between the first heat exchange fin 12 and the second heat exchange fin 15 is increased by adjusting the heat exchange speed control unit 4. When the fuel flow monitoring value decreases, the axial projection overlap area between the first heat exchange fin 12 and the second heat exchange fin 15 is reduced by the heat exchange speed control unit 4.

[0067] A fuel temperature monitor 44 is provided on the fuel pipeline 22, and the fuel temperature monitor 44 is electrically connected to the heat exchange speed control unit 4;

[0068] The heat exchange rate control unit 4 is configured to control the action of the rotating mechanism 41 according to the monitoring value of the fuel temperature monitor 44;

[0069] When the fuel temperature value monitored by the fuel temperature monitor 44 decreases, the heat exchange speed control unit 4 adjusts the axial projection overlap area between the first heat exchange fin 12 and the second heat exchange fin 15 to increase. When the fuel temperature monitoring value increases, the heat exchange speed control unit 4 drives the axial projection overlap area in the bracket of the first heat exchange fin 12 and the second heat exchange fin 15 to decrease.

[0070] Based on this embodiment, a monitor for monitoring fuel flow and temperature performs real-time monitoring of fuel flow and temperature, and a heat exchange rate control unit adjusts the size of the axial projection overlap area of ​​the first heat exchange fin 12 and the second heat exchange fin 15 according to the monitored fuel flow and temperature information, thereby accurately controlling the heat exchange rate between the two heat exchange tubes, improving the LNG vaporization rate and maintaining a reasonable water temperature for the cooling water, achieving a balanced operating condition of the engine, improving operating efficiency, and reducing energy consumption.

[0071] Embodiment 3:

[0072] On the basis of the LNG internal combustion powered ship waste heat utilization device of Example 1, an intermediate baffle and a circulation pump may be provided in the heat exchange box 1, wherein the intermediate baffle is provided at the bottom of the second heat exchange tube 14 and extends along the length direction of the second baffle, the suction end of the circulation pump is connected to the space on one side of the intermediate baffle, and the output end is connected to the space on the other side of the intermediate baffle, and the heat conduction controller is connected to the circulation pump control, and when the axial projection overlap area between the first heat exchange fin plate 12 and the second heat exchange fin plate 15 increases, the circulation pump is controlled to increase the displacement, and when the axial projection overlap area between the first heat exchange fin plate 12 and the second heat exchange fin plate 15 decreases, the circulation pump is controlled to reduce the displacement, so as to achieve uniform temperature of the heat transfer liquid between the first heat exchange tooth plate and the second heat exchange tooth plate, which is beneficial to the balance of heat exchange.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A waste heat utilization device for LNG internal combustion powered ships, characterized in that: It comprises a heat exchange box (1) and a heat exchange speed control unit (4); The heat exchange box (1) is provided with a first heat exchange tube (11) and a second heat exchange tube (14) which are parallel to each other and extend in the horizontal direction; the first heat exchange tube (11) and the second heat exchange tube (14) both penetrate the side walls at both ends of the heat exchange box (1) and are sealed and rotatably connected to the heat exchange box (1); the heat exchange box (1) is filled with a heat transfer fluid; The first heat exchange tube (11) is sealed and rotatably connected to the cooling water pipeline (21) of the engine (2), and a plurality of first heat exchange fins (12) are arranged in an array along the length direction of the tube surface located in the heat exchange box (1); the second heat exchange tube (14) is sealed and rotatably connected to the fuel pipeline (22) between the LNG storage tank (3) and the engine (2), and a plurality of second heat exchange fins (15) are arranged in an array along the length direction of the tube surface located in the heat exchange box (1); the plurality of first heat exchange fins (12) and the plurality of second heat exchange fins (15) are arranged in an alternating manner; The heat exchange speed control unit (4) is configured to adjust the size of the axially projected overlap area between the first heat exchange fin (12) and the second heat exchange fin (15) by controlling the rotation of the first heat exchange tube (11) and the second heat exchange tube (14).

2. The LNG internal combustion powered ship waste heat utilization device according to claim 1 is characterized in that: The first heat exchange fin (12) and the second heat exchange fin (15) are both circular plates; the first heat exchange tube (11) passes through the first heat exchange fin (12) and the axis of the first heat exchange tube (11) is eccentrically arranged relative to the axis of the first heat exchange fin (12); the second heat exchange tube (14) passes through the second heat exchange fin (15) and the axis of the second heat exchange tube (14) is eccentrically arranged relative to the axis of the second heat exchange fin (15).

3. The LNG internal combustion powered ship waste heat utilization device according to claim 2 is characterized in that: The heat exchange speed control unit (4) comprises a rotating mechanism (41) capable of driving the first heat exchange tube (11) to rotate, and a constant speed transmission mechanism (42) arranged between the first heat exchange tube (11) and the second heat exchange tube (14); when the first heat exchange tube (11) rotates, the constant speed transmission mechanism (42) drives the second heat exchange tube (14) to rotate in a constant speed circumferential direction; The eccentric direction of the axis of the first heat exchange tube (11) relative to the axis of the first heat exchange fin (12) and the eccentric direction of the axis of the second heat exchange tube (14) relative to the axis of the second heat exchange fin (15) are symmetrically arranged.

4. The LNG internal combustion powered ship waste heat utilization device according to claim 3 is characterized in that: The heat exchange speed control unit (4) drives the first heat exchange tube (11) and the second heat exchange tube (14) to rotate. When the distance between the axes of the first heat exchange fin (12) and the second heat exchange fin (15) is the smallest, the second heat exchange fin (15) is inserted between two adjacent first heat exchange fins (12), and the axial projection overlap area between the first heat exchange fin (12) and the second heat exchange fin (15) is the largest; when the distance between the axes of the first heat exchange fin (12) and the second heat exchange fin (15) is the largest, the axial projection overlap area between the first heat exchange fin (12) and the second heat exchange fin (15) is the smallest or there is no axial projection overlap area.

5. The LNG internal combustion powered ship waste heat utilization device according to claim 4 is characterized in that: The first heat exchange tube (11) is located directly above the second heat exchange tube (14); the heat transfer liquid level (5) of the heat transfer liquid in the heat exchange box (1) is higher than the first heat exchange tube (11); and when the axial projection overlap area between the first heat exchange fin (12) and the second heat exchange fin (15) is the smallest or has no axial projection overlap area, the portion of the first heat exchange fin (12) located above the first heat exchange tube (11) is mostly exposed to the heat transfer liquid level (5).

6. The LNG internal combustion powered ship waste heat utilization device according to claim 3, characterized in that: The constant speed transmission mechanism (42) comprises a driving gear and a driven gear with equal numbers of teeth and meshing with each other, the driving gear being connected to the first heat exchange tube (11), and the driven gear being connected to the second heat exchange tube (14); the rotating mechanism (41) comprises an adjusting motor and a belt transmission assembly, the driving pulley of the belt transmission assembly being connected to the motor shaft of the adjusting motor; the driven pulley of the belt transmission assembly being connected to the first heat exchange tube (11), the transmission belt being arranged between the driving pulley and the driven pulley, and the adjusting motor driving the first heat exchange tube (11) to rotate through the belt transmission assembly.

7. The LNG internal combustion powered ship waste heat utilization device according to any one of claims 1 to 6, characterized in that: The fuel pipeline (22) is provided with a fuel flow monitor (43), and the fuel flow monitor (43) is electrically connected to the heat exchange speed control unit (4); The heat exchange speed control unit (4) is configured to control the operation of the rotating mechanism (41) according to the monitoring value of the fuel flow monitor (43); When the fuel flow rate value monitored by the fuel flow rate monitor (43) increases, the axial projection overlap area between the first heat exchange fin (12) and the second heat exchange fin (15) is increased by adjusting the heat exchange rate control unit (4); when the fuel flow rate monitoring value decreases, the axial projection overlap area between the first heat exchange fin (12) and the second heat exchange fin (15) is decreased by driving the heat exchange rate control unit (4).

8. The LNG internal combustion powered ship waste heat utilization device according to any one of claims 1 to 6, characterized in that: The fuel pipeline (22) is provided with a fuel temperature monitor (44), and the fuel temperature monitor (44) is electrically connected to the heat exchange speed control unit (4); The heat exchange speed control unit (4) is configured to control the operation of the rotating mechanism (41) according to the monitoring value of the fuel temperature monitor (44); When the fuel temperature value monitored by the fuel temperature monitor (44) decreases, the heat exchange speed control unit (4) adjusts the axial projection overlap area between the first heat exchange fin (12) and the second heat exchange fin (15) to increase; when the fuel temperature monitoring value increases, the heat exchange speed control unit (4) drives the axial projection overlap area in the bracket of the first heat exchange fin (12) and the second heat exchange fin (15) to decrease.

9. The LNG internal combustion powered ship waste heat utilization device according to any one of claims 1 to 6, characterized in that: Both ends of the first heat exchange tube (11) are sealed and rotatably connected to the cooling water pipeline (21) via a first rotary sealing mechanism (13), and both ends of the second heat exchange tube (14) are sealed and rotatably connected to the fuel pipeline (22) via a second rotary sealing mechanism (16).

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