Heat tracing device for methanol recovery pipeline of engine

Abstract

The embodiment of the utility model provides a heat tracing device for a methanol recovery pipeline of an engine, which comprises a heat tracing assembly arranged at a methanol recovery header pipe. According to the embodiment of the utility model, the heat tracing assembly is additionally arranged at the methanol recovery header pipe where the methanol fuel is easy to liquefy and agglomerate, and the liquid methanol fuel is re-vaporized through the heat tracing assembly, so that the liquid methanol fuel is blown out of the machine along with inert gas in a gas form and enters the methanol recovery tank in the auxiliary system; the problem that the methanol liquid in the methanol recovery pipeline of the methanol fuel engine cannot be completely purged is effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of marine engine technology, and in particular to a heat tracing device for methanol recovery pipeline in an engine. Background Technology

[0002] In the process of transformation of the shipping industry, if significant reductions in greenhouse gas emissions are to be achieved, the shift from traditional fossil fuels to green and low-carbon fuels such as LNG, methanol, and hydrogen / ammonia in ship engines has become an inevitable trend. Methanol fuel, in particular, is considered one of the most promising technological pathways for future green and low-carbon fuels due to its physicochemical properties, which make its transportation, storage, and supply most similar to traditional fossil fuels. Furthermore, this fuel can be synthesized from renewable energy sources. Methanol is a colorless, transparent liquid that is volatile, has a pungent odor, and is toxic. It has a boiling point of 64.7℃ at room temperature and pressure, an auto-ignition temperature of 464℃, strong hydrophilicity, and a viscosity higher than gasoline but lower than diesel.

[0003] After a dual-fuel engine operating in methanol mode has finished running, or after an emergency shutdown in methanol mode, inert gas is typically used to purge the methanol fuel lines to ensure safety. However, since methanol is usually a liquid at room temperature, purging the liquid lines with gas often results in incomplete purging of the liquid. Utility Model Content

[0004] In view of the above-mentioned problems existing in the prior art, this utility model provides a heat tracing device for engine methanol recovery pipeline to solve the technical problem of incomplete purging of methanol fuel pipeline in the prior art.

[0005] This utility model embodiment provides a heat tracing device for an engine methanol recovery pipeline, comprising:

[0006] A heat tracing assembly is installed at the methanol recovery main pipe.

[0007] In one embodiment, the heat tracing assembly is a heat tracing pipe, the water inlet of which is connected to the cylinder head high-temperature water outlet main pipe, and the heat tracing pipe is arranged along the length of the methanol recovery main pipe.

[0008] In one embodiment, a heat tracing switch valve is provided at the water inlet end of the heat tracing pipe.

[0009] In one embodiment, the heat tracing pipe is installed between the inner and outer pipes 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 heat tracing pipe.

[0013] In one embodiment, a temperature sensor is provided at the outlet end of the heat tracing pipe.

[0014] In one embodiment, the heating component is a heating wire.

[0015] In one embodiment, the heat tracing pipe is a stainless steel pipe.

[0016] Compared with the prior art, the beneficial effect of the engine methanol recovery pipeline heat tracing device provided by this utility model embodiment is that: by adding a heat tracing component at the methanol recovery main pipe where methanol fuel is prone to liquefaction and agglomeration, the liquid methanol fuel is re-vaporized by the heat tracing component, and then blown out of the engine in gaseous form along with inert gas and into the methanol recovery tank in the auxiliary system, the present utility model embodiment effectively solves the problem of incomplete purging of methanol liquid in the methanol recovery pipeline of methanol fuel engine. Attached Figure Description

[0017] Figure 1 A schematic diagram of the structure of a heat tracing device for an engine methanol recovery pipeline provided in this embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the cross-sectional structure of the methanol recovery main pipe of an engine methanol recovery pipeline heat tracing device provided in an embodiment of the present utility model.

[0019] Figure label:

[0020] 1. Engine block or frame; 2. Cylinder head; 3. Methanol injector; 4. Methanol inlet manifold; 5. Single-cylinder methanol inlet pipe; 6. Methanol recovery manifold; 7. Single-cylinder methanol return pipe; 8. Cylinder head high-temperature water outlet manifold; 9. Single-cylinder cylinder head high-temperature water outlet pipe; 10. Heat tracing pipe; 11. Heat tracing switch valve; 12. Inert gas purge pipe; 13. Purge valve; 14. Heating assembly; 15. Temperature sensor. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0023] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0024] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0025] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0026] Specific embodiments of this application are described below with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to ascertain the true intent based on the user's historical operations, and to avoid unnecessary or redundant details that would obscure this application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in various ways with substantially any suitable detailed structure.

[0027] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0028] The principles and features of this utility model are described below with reference to the accompanying drawings. The embodiments described are only for explaining this utility model and are not intended to limit the scope of this utility model. The following description, in conjunction with... Figure 1-2 The preferred embodiments of this utility model will be described in further detail below:

[0029] like Figure 1-2 As shown, compared to a traditional diesel engine, a diesel-methanol dual-fuel engine typically adds a methanol inlet manifold 4 (or methanol rail), one or more methanol injectors 3 per cylinder, a single-cylinder methanol inlet manifold 5 and a single-cylinder methanol return manifold 7 matched to the methanol injectors 3, a methanol recovery manifold 6, an inert gas purge pipe 12, and a purge valve 13. To ensure safe operation, the methanol fuel lines (including the methanol inlet manifold 4, the single-cylinder methanol inlet manifold 5, the single-cylinder methanol return manifold 7, and the methanol recovery manifold 6) usually use double-walled pipes, such as... Figure 2 As shown.

[0030] After a dual-fuel engine operating in methanol mode has finished running, or after an emergency shutdown in methanol mode, inert gas is typically used to purge the methanol fuel line to ensure safety and prevent methanol residue from remaining in the line. The methanol fuel line is usually designed with a specific angle to allow liquid methanol to flow out of the engine's methanol fuel line under its own weight. However, because methanol is a liquid at room temperature and pressure and has a certain viscosity, inert gas purging often results in incomplete purging.

[0031] To address this problem, this utility model provides a heat tracing device for an engine methanol recovery pipeline, comprising:

[0032] The heat tracing component is installed at the methanol recovery main pipe 6. The heat tracing component can be in the form of electric heating wire, water bath heating, or a combination of electric heating wire and water bath heating. The reason for only heat tracing the methanol recovery main pipe 6 is that the residual temperature at the methanol return pipe 7 of the single cylinder is relatively high, and the methanol will not liquefy and accumulate. However, the methanol recovery main pipe 6 is relatively long, and the methanol is prone to cooling and liquefaction. Therefore, focusing the heat tracing on this part can reduce the difficulty of modification and save costs.

[0033] To fully utilize the existing system structure and leverage its synergistic effects, in one embodiment, the heat tracing component is a heat tracing pipe 10. The 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 runs along the entire length of the methanol recovery main pipe 6. That is, a branch of high-temperature water from the cylinder head high-temperature water outlet main pipe 8 serves as the inlet water for 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 allows the methanol at atmospheric pressure to vaporize rapidly, making it easier to purge with inert gas. Furthermore, using high-temperature water is safer than using an electric heat tracing pipe.

[0034] When the system is in diesel mode, there will be no methanol accumulation in the methanol fuel pipeline. Therefore, in one embodiment, a heat tracing switch valve 11 is provided at the water inlet of the heat tracing pipe 10. The heat tracing switch valve 11 can control the flow of high-temperature water in the heat tracing pipe 10. On the one hand, it can simplify the return water path, and on the other hand, it can avoid the long service life of the small-diameter heat tracing pipe 10, avoid the problem of scale buildup inside, and extend its service life.

[0035] In order to improve the heat tracing efficiency and at the same time provide some protection for the heat tracing pipe 10, the heat tracing pipe 10 is installed between the inner pipe and the outer pipe of the methanol recovery main pipe 6. That is, the heat tracing pipe 10 is installed in a way that is directly attached to the outer wall of the inner pipe of the methanol recovery main pipe 6, so as to ensure that the heat of the heat tracing pipe 10 can be transferred to the methanol recovery main pipe 6 more directly, faster and more efficiently.

[0036] Considering the purpose of setting up the heat tracing pipe 10 and the space for installation and removal, in one embodiment, 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. Under normal circumstances, the inner diameter of the heat tracing pipe 10 is between 15% and 20% of the inner diameter of the inner pipe of the methanol recovery main pipe 6, so as to ensure that the heat tracing pipe 10 can provide sufficient heat while being as thin as possible.

[0037] From a heat tracing perspective, the heat tracing pipe 10 can be configured as a spiral pipe coiled around the methanol recovery main pipe 6, or as a sleeve form that encloses the methanol recovery main pipe 6. However, considering that the heat required for methanol vaporization in the pipeline is limited most of the time, and that methanol fuel pipelines usually use double-walled pipes with limited installation space, it is necessary to minimize the installation difficulty. Therefore, the diameter of the heat tracing pipe 10 should not be too large. In order to reduce the accumulation of scale inside the heat tracing pipe 10, in one embodiment, the heat 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 pipe-shaped heat tracing pipe 10 also has the advantage of low installation, disassembly and maintenance difficulty.

[0038] In one embodiment, considering that the water temperature in the cylinder head high-temperature water outlet main pipe 8 may be limited during the system startup phase or the system continuous low-load operation phase, the heat provided by the heat tracing pipe 10 may be insufficient. Therefore, a heating component 14 can be added to the water inlet end of the heat tracing pipe 10 to heat the heat tracing pipe 10 and increase the water temperature inside the heat tracing pipe 10. Of course, the design of the heating component 14 can also be in the form of electric heating wire heating, water bath heating, or a combination of electric heating wire heating and 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 most of the time, from the perspective of energy saving, the outlet end of the heat tracing pipe 10 is equipped with a temperature sensor 15, which monitors the outlet water temperature in real time through the temperature sensor 15, and when the temperature is too low, it feeds back to the control system to start the heating component 14 (that is, the heating component 14 is designed to be normally closed).

[0040] In one embodiment, the heat tracing pipe 10 is a stainless steel pipe, that is, the inner and outer pipes of the heat tracing pipe 10 and the methanol recovery main pipe 6 are all made of stainless steel pipes. On the one hand, this can improve durability, and on the other hand, the existing segmented welding assembly process can be used to reduce assembly difficulty.

[0041] When the engine starts running in methanol mode, the control system simultaneously opens the high-temperature water tracing valve 11, and a portion of the high-temperature water from the cylinder head outlet begins to heat the methanol recovery manifold 6. At this time, there is no methanol in the methanol recovery manifold 6. After the methanol mode operation is completed, or after an emergency stop in methanol mode, the control system opens the inert gas purging valve 13, and inert gas with a pressure higher than that of methanol fuel entering the engine is introduced from the methanol inlet manifold (or methanol rail) to begin purging 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, reaching the methanol recovery manifold 6. Since the methanol recovery manifold 6 has been heated by high-temperature water at 85°C, the purged methanol fuel is less likely to form a liquid accumulation and will be blown out of the engine in gaseous form along with the inert gas, entering the methanol recovery tank in the auxiliary system, thus completing the methanol fuel system purging process on the engine.

[0042] The above embodiments are merely exemplary embodiments of this utility model and are not intended to limit this utility model. The scope of protection of this utility model is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this utility model within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this utility model.

Claims

1. An engine methanol recovery line heat tracing apparatus, characterized by, The application relates to a methanol recovery system, which comprises: a heat tracing assembly arranged at a methanol recovery main pipe (6); the heat tracing assembly is a heat tracing pipe (10), the water inlet end of the heat tracing pipe (10) is connected to a cylinder cover high-temperature water outlet main pipe (8), and the heat tracing pipe (10) is arranged along the methanol recovery main pipe (6).

2. An engine methanol recovery line heat tracing apparatus as claimed in claim 1, characterized in that: The water inlet end of the heat tracing pipe (10) is provided with a heat tracing switch valve (11).

3. An engine methanol recovery line heat tracing apparatus as defined in claim 1, wherein: The heat tracing pipe (10) is arranged between the inner pipe and the outer pipe of the methanol recovery main pipe (6).

4. An engine methanol recovery line heat tracing apparatus as claimed in claim 3, characterized in that: The heat tracing pipe (10) is a straight pipe which is fixedly attached to the position of the outer wall of the inner pipe of the methanol recovery main pipe (6).

5. An engine methanol recovery line heat tracing apparatus as claimed in claim 4, 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).

6. An engine methanol recovery line heat tracing apparatus as defined in claim 1, wherein: The water inlet end of the heat tracing pipe (10) is provided with a heating assembly (14).

7. An engine methanol recovery line heat tracing apparatus as claimed in claim 6, characterized in that: The water outlet end of the heat tracing pipe (10) is provided with a temperature sensor (15).

8. An engine methanol recovery line heat tracing apparatus as defined in claim 6, wherein: The heating assembly (14) is an electric heating wire.

9. An engine methanol recovery line heat tracing apparatus as set forth in claim 1 wherein: The heat tracing pipe (10) is a stainless steel pipe.

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