Heat tracing device for methanol recovery pipeline of engine
By setting up a heat tracing assembly in the engine methanol recovery pipeline, the liquid methanol is vaporized and purged together with the inert gas, the problem of unclean purge of the methanol fuel pipeline is solved, and the complete recovery and treatment of methanol fuel is achieved.
Patent Information
- Application Number
- CN202510361552.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2025-05-27
AI Technical Summary
In dual fuel engines using diesel and methanol, the methanol fuel line often fails to be completely clean when purged, resulting in liquid methanol residues.
A heating tracing device for the methanol recovery pipeline of the engine is designed. By installing a heat tracing assembly at the methanol recovery main pipe, the liquid methanol is re-evaporated by heating with high temperature water or electric heating wire, so that it can be purged with the inert gas.
It effectively solves the problem of unclean purge of methanol fuel pipelines, ensures complete recycling and treatment of methanol fuel, and improves the safety and reliability of the engine.
Smart Images
Figure CN120042691A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of ship engines, and particularly to a heat tracing device for an engine methanol recovery pipeline. Background Art
[0002] In the process of the shipping industry's transformation, if greenhouse gas emissions are to be significantly reduced, it has become an inevitable trend for ship engines to switch from using traditional fossil fuels to using green and low-carbon fuels such as LNG, methanol, hydrogen / ammonia, etc. Especially methanol fuel, its physical and chemical properties determine that its transportation, storage, and supply are closest to traditional fossil fuels, and this fuel can be synthesized from renewable energy. Therefore, it is regarded as one of the most potential technical approaches for future green and low-carbon fuels in the industry. Methanol fuel is a colorless and transparent liquid, volatile, with a pungent odor, toxic, boiling point 64.7°C at normal temperature and pressure, autoignition temperature 464°C, with strong hydrophilicity, viscosity higher than gasoline but lower than diesel.
[0003] After the operation of a dual-fuel engine using diesel and methanol in methanol mode is completed, or after an emergency stop in methanol mode, in order to ensure safety, inert gas is usually used to purge the methanol fuel pipeline to empty the methanol fuel pipeline. Since methanol fuel is usually in a liquid state at normal temperature, when purging a liquid pipeline with gas, there are often problems with incomplete purging of the liquid. Summary of the Invention
[0004] In view of the above problems existing in the prior art, an embodiment of the present invention provides a heat tracing device for an engine methanol recovery pipeline to solve the technical problem of incomplete purging of the methanol fuel pipeline existing in the prior art.
[0005] An embodiment of the present invention provides a heat tracing device for an engine methanol recovery pipeline, including:
[0006] A heat tracing component, which is arranged at the methanol recovery main pipe.
[0007] In one embodiment, the heat tracing component is a heat tracing pipe, the water inlet end of the heat tracing pipe is connected to the cylinder head high-temperature water outlet main pipe, and the heat tracing pipe is arranged along the entire length of the methanol recovery main pipe.
[0008] In one embodiment, a heat tracing switch valve is arranged at the water inlet end of the heat tracing pipe.
[0009] In one embodiment, the heat tracing pipe is arranged between the inner pipe and the outer pipe of the methanol recovery main pipe.
[0010] In one embodiment, the heat tracing pipe is a straight pipe fixedly attached to the outer wall of the inner pipe of the methanol recovery main pipe.
[0011] In one embodiment, the inner diameter of the heat tracing pipe is not less than one-tenth of the inner diameter of the inner pipe of the methanol recovery main pipe.
[0012] In one embodiment, a heating component is provided at the water inlet end of the tracing pipe.
[0013] In one embodiment, a temperature sensor is provided at the water outlet end of the tracing pipe.
[0014] In one embodiment, the heating component is an electric heating wire.
[0015] In one embodiment, the tracing pipe is a stainless steel pipe.
[0016] Compared with the prior art, the beneficial effect of a methanol recovery pipeline tracing device for an engine provided by an embodiment of the present invention is as follows: By adding a tracing component at the methanol recovery main pipe where methanol fuel liquefaction and agglomeration are likely to occur, the tracing component re-vaporizes the liquid methanol fuel, and then it is blown out of the engine together with the inert gas in a gaseous state and enters the methanol recovery tank in the auxiliary system, effectively solving the problem that the methanol liquid in the methanol recovery pipeline of the methanol fuel engine cannot be purged cleanly. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 is a schematic structural diagram of a methanol recovery pipeline tracing device for an engine provided by an embodiment of the present invention;
[0018] Figure 2 is a schematic cross-sectional structural diagram of the methanol recovery main pipe of a methanol recovery pipeline tracing device for an engine provided by an embodiment of the present invention.
[0019] Reference Signs:
[0020] 1, engine body or frame; 2, cylinder head; 3, methanol injector; 4, main methanol inlet pipe; 5, single-cylinder methanol inlet pipe; 6, methanol recovery main pipe; 7, single-cylinder methanol return pipe; 8, main cylinder head high-temperature water outlet pipe; 9, single-cylinder cylinder head high-temperature water outlet pipe; 10, tracing pipe; 11, tracing switch valve; 12, inert gas purge pipe; 13, purge valve; 14, heating component; 15, temperature sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0022] Reference is made herein to the various solutions and features of the present application as described with reference to the drawings.
[0023] These and other features of the present application will become apparent from the following description of the preferred forms of the embodiments given as non-limiting examples with reference to the accompanying drawings.
[0024] It should also be understood that, although the present application has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present application, which have the features as described in the claims and thus are all within the protection scope defined hereby.
[0025] When combined with the accompanying drawings, the above and other aspects, features and advantages of the present application will become more obvious in view of the following detailed description.
[0026] Specific embodiments of the present application will be described hereinafter with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of the present application, which can be implemented in various ways. Well-known and / or repetitive functions and structures are not described in detail to clarify the true intention based on the user's historical operations and to avoid obscuring the present application with unnecessary or redundant details. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present application in substantially any suitable detailed structure in a variety of ways.
[0027] This specification may use the phrases "in one embodiment", "in another embodiment", "in yet another embodiment" or "in other embodiments", which may each refer to one or more of the same or different embodiments according to the present application.
[0028] The principles and features of the present invention will be described hereinafter with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention. The following Figure 1-2 , a further detailed description of the preferred embodiments of the present invention will be given:
[0029] As Figure 1-2 shown, compared with a traditional diesel engine, a diesel-methanol dual-fuel engine usually adds a methanol inlet main pipe 4 (or methanol rail) for one more path, one or more methanol injectors 3 are newly added to each cylinder, a single-cylinder methanol inlet pipe 5 and a single-cylinder methanol return pipe 7 that are matched with the methanol injector 3, a methanol recovery main pipe 6 for one path, an inert gas purge pipe 12 and a purge valve 13 for one path. To ensure safe use, the methanol fuel pipeline (including the methanol inlet main pipe 4, the single-cylinder methanol inlet pipe 5, the single-cylinder methanol return pipe 7 and the methanol recovery main pipe 6) usually uses a double-wall pipe, as Figure 2 shown.
[0030] After the methanol mode operation of a dual-fuel engine using diesel and methanol is completed, or after an emergency shutdown in methanol mode, in order to ensure safety, inert gas is usually used to purge the methanol fuel pipeline so that no methanol remains in the pipeline. When designing the methanol pipeline, a certain inclination angle is usually ensured so that liquid methanol can flow out of the methanol fuel pipeline on the engine by its own gravity. However, since methanol is a liquid under normal temperature and pressure and has a certain viscosity, there is often an incomplete purging situation when using inert gas for purging.
[0031] To solve this problem, an embodiment of the present invention provides a heat tracing device for an engine methanol recovery pipeline, including:
[0032] A heat tracing component, the heat tracing component is arranged at the methanol recovery main pipe 6. Among them, the form of the heat tracing component includes but is not limited to design forms such as electric wire heating, water bath heating, and a combination of electric wire heating + water bath heating. Of course, heat tracing heating is only carried out at the methanol recovery main pipe 6 because the residual temperature at the single-cylinder methanol return pipe 7 is relatively high and methanol will not liquefy and accumulate. However, at the methanol recovery main pipe 6, because the distance is long, methanol is prone to cooling and liquefaction. Therefore, focusing on heat tracing heating at this part can reduce the transformation difficulty and save costs;
[0033] From the perspective of making full use of the existing structure of the system and giving play to the synergistic effect of the existing structure of the system, in one embodiment, the heat tracing component is a heat tracing pipe 10. The water inlet end of the heat tracing pipe 10 is connected to the cylinder head high-temperature water outlet main pipe 8, and the heat tracing pipe 10 is arranged along the entire length of the methanol recovery main pipe 6. That is, a path of high-temperature water is separated from the cylinder head high-temperature water outlet main pipe 8 as the inlet water of the heat tracing pipe 10 to heat the methanol recovery main pipe 6. The outlet temperature of the cylinder head high-temperature cooling water is generally higher than 85°C. Using 85°C high-temperature water to heat the methanol recovery main pipe 6 can quickly vaporize methanol under normal pressure. At this time, it is easier to purge it cleanly with inert gas. In addition, using high-temperature water is safer than using an electric heat tracing pipe for heating.
[0034] When the system is in diesel mode, there will be no problem of methanol accumulation in the methanol fuel pipeline. Therefore, in one embodiment, a heat tracing switch valve 11 is arranged at the water inlet end of the heat tracing pipe 10. Through the heat tracing switch valve 11, the on-off of the high-temperature water in the heat tracing pipe 10 can be controlled. On the one hand, it can simplify the return water path. On the other hand, it can also avoid the service life of the small-diameter heat tracing pipe 10 and prevent fouling inside it, thereby prolonging its service life;
[0035] To improve the heat tracing efficiency and play a certain protective role for the heat tracing pipe 10, the heat tracing pipe 10 is arranged between the inner pipe and the outer pipe of the methanol recovery main pipe 6. That is, the heat tracing pipe 10 is arranged in a way that directly adheres to the outer wall of the inner pipe of the methanol recovery main pipe 6 to ensure that the heat of the heat tracing pipe 10 can be transferred to the inside of the methanol recovery main pipe 6 more directly, quickly, and efficiently;
[0036] Considering the purpose of setting the tracing pipe 10 and the installation and removal space, in one embodiment, the inner pipe diameter of the tracing pipe 10 is not less than one-tenth of the inner pipe diameter of the methanol recovery main pipe 6. Generally, the inner pipe diameter of the tracing pipe 10 is between 15% and 20% of the inner pipe diameter of the methanol recovery main pipe 6, so as to ensure that the tracing pipe 10 can provide sufficient heat while being as thin as possible;
[0037] From the perspective of tracing heat, the tracing pipe 10 can be set as a spiral pipe coiled around the methanol recovery main pipe 6, or set as a sleeve form that envelopes the methanol recovery main pipe 6. However, considering that the heat required for methanol vaporization in the pipeline is limited for most of the time, and the methanol fuel pipeline usually uses double-wall pipes, and the installation space is limited and the installation difficulty needs to be reduced as much as possible. Therefore, the pipe diameter of the tracing pipe 10 is usually not too large. In order to reduce the fouling phenomenon in the tracing pipe 10, in one embodiment, the tracing pipe 10 is a straight pipe fixedly attached to the outer wall of the inner pipe of the methanol recovery main pipe 6. Moreover, the straight-tube tracing pipe 10 also has the advantage of low installation and maintenance difficulty;
[0038] In one embodiment, considering that during the system startup phase or the system continuous low-load operation phase, the water temperature in the cylinder head high-temperature water outlet main pipe 8 may be limited. At this time, the heat provided by the tracing pipe 10 may be insufficient. For this reason, a heating component 14 can be further added to the water inlet end of the tracing pipe 10 to heat the tracing pipe 10 to increase the water temperature in the tracing pipe 10. Of course, the design form of the heating component 14 can also be in the form of electric wire heating, water bath heating, and a combination of electric wire heating + water bath heating;
[0039] Based on the above, in one embodiment, since the water temperature in the cylinder head high-temperature water outlet main pipe 8 is sufficient for most of the time, from the perspective of energy conservation, a temperature sensor 15 is provided at the water outlet end of the tracing pipe 10. The water outlet temperature is monitored in real time through the temperature sensor 15, and when the temperature is too low, it is fed back to the control system to start the heating component 14 (that is, the heating component 14 is designed as a normally closed form);
[0040] In one embodiment, the tracing pipe 10 is a stainless steel pipe, that is, the inner pipe and the outer pipe of the tracing pipe 10 and the methanol recovery main pipe 6 are all made of stainless steel pipes. On the one hand, it can improve the durability, and on the other hand, it can also adopt the existing segmented welding assembly process to reduce the assembly difficulty.
[0041] When the engine starts running in methanol mode, the control system simultaneously opens the high-temperature water tracing switch valve 11. A part of the high-temperature water at the cylinder head outlet starts to heat the methanol recovery main pipe 6. At this time, there is no methanol in the methanol recovery main pipe 6. After the methanol mode operation is completed or after an emergency stop of the methanol mode, the control system opens the inert gas purge valve 13. The inert gas with a pressure higher than the methanol fuel inlet pressure of the engine is filled into the methanol inlet main pipe (or methanol rail), and starts to purge the methanol in the system. The inert gas flows into the single-cylinder methanol inlet pipe 5, the methanol injection valve 3, and the single-cylinder methanol return pipe 7 and reaches the methanol recovery main pipe 6. Since the methanol recovery main pipe 6 has been heated by the high-temperature water at 85°C, the purged methanol fuel is not likely to form liquid accumulation and will be blown out of the engine in gaseous form along with the inert gas and enter the methanol recovery tank in the auxiliary system, thus completing the purging process of the on-engine methanol fuel system.
[0042] The above embodiments are only exemplary embodiments of the present invention and are not used to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present invention, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present invention.
Claims
1. A heating device for an engine methanol recovery pipeline, characterized in that: include: A heating component is provided at the methanol recovery main pipe (6).
2. The engine methanol recovery pipeline heating device according to claim 1, characterized in that: The heating component is a heating pipe (10), the water inlet end of the heating pipe (10) is connected to the cylinder head high-temperature water outlet main pipe (8), and the heating pipe (10) is arranged along the entire length of the methanol recovery main pipe (6).
3. The engine methanol recovery pipeline heating device according to claim 1, characterized in that: A heating switch valve (11) is provided at the water inlet end of the heating pipe (10).
4. The engine methanol recovery pipeline heating device according to claim 1, characterized in that: The heating pipe (10) is inserted between the inner pipe and the outer pipe of the methanol recovery main pipe (6).
5. The engine methanol recovery pipeline heating device according to claim 4, characterized in that: The heating pipe (10) is a straight pipe fixedly attached to the outer wall of the inner pipe of the methanol recovery main pipe (6).
6. The engine methanol recovery pipeline heating device according to claim 5, characterized in that: The inner diameter of the heat tracing pipe (10) is not less than one tenth of the inner diameter of the inner pipe of the methanol recovery main pipe (6).
7. The engine methanol recovery pipeline heating device according to claim 2, characterized in that: A heating component (14) is provided at the water inlet end of the heating pipe (10).
8. The engine methanol recovery pipeline heating device according to claim 7, characterized in that: A temperature sensor (15) is provided at the water outlet end of the heating pipe (10).
9. The engine methanol recovery pipeline heating device according to claim 7, characterized in that: The heating component (14) is an electric heating wire.
10. The engine methanol recovery pipeline heating device according to claim 2, characterized in that: The heating pipe (10) is a stainless steel pipe.