Fuel supply pipe system for methanol-fueled engine having heating function

Abstract

A fuel supply pipe system having a heating function for a methanol-fueled engine. The fuel supply pipe system comprises a plurality of three-layer pipes, a plurality of adapter blocks, and a plurality of position-limiting plates. Each three-layer pipe comprises an inner pipe, a middle pipe, an outer pipe, and two arc-shaped PTC heating plates embedded in an annular recess on the outer periphery of the inner pipe, the middle pipe being inserted into the outer pipe and being fixedly connected to the outer pipe as a whole. An outer pipe annular cavity serving as a nitrogen channel is provided between an inner hole of each outer pipe and the outer peripheral surface of a middle pipe; central holes of the adapter blocks are communicated with the inner pipes to serve as methanol fuel channels. Both ends of the three-layer pipes are respectively fixedly connected by means of the adapter blocks and the position-limiting plates to form the integral pipe system. The present invention significantly reduces the manufacturing costs of engines; the arc-shaped PTC heating plates after being energized heat methanol fuel in the inner pipes, thus effectively improving the low-temperature cold start performance of methanol-fueled engines, and comprehensively improving the safety performance of methanol-fueled engines and the purging efficiency of methanol fuel.

Description

Fuel supply system for methanol fuel engines with heating function Technical Field

[0001] This invention relates to a fuel supply system for a new energy engine, and more particularly to a fuel supply pipeline system for a methanol fuel engine capable of heating methanol fuel, belonging to the field of new energy engine technology. Background Technology

[0002] Methanol fuel, with its advantages of being clean, environmentally friendly, and widely available, has shown great application potential in the field of new energy engines. However, its high latent heat of vaporization has brought many challenging problems to its practical application in engines.

[0003] In terms of cold starts at low temperatures, methanol fuel faces significant challenges regardless of whether it's direct injection or port injection. During a cold start, the methanol fuel injected into the engine intake manifold often exhibits poor vaporization, entering the cylinder in liquid form. This not only dilutes the lubricating oil, affecting the engine's lubrication system, but also lowers the cylinder temperature under low to medium loads, causing the flame front to quench on the cylinder walls, leading to incomplete combustion. This results in decreased engine performance and increased emissions from methanol fuel engines.

[0004] Meanwhile, the toxicity of methanol fuel cannot be ignored; it is extremely harmful to the human nervous and circulatory systems. If a new fuel engine leaks methanol during operation, it could potentially cause serious safety accidents, threatening human life and health as well as the safety of the surrounding environment. Even in unburned form, methanol vapor evaporation or accidental splashes onto the skin can cause significant harm. To address the problem of cold starts in methanol fuel engines, existing improvements mainly fall into two categories: one is to use an external auxiliary fuel tank and add a fuel injection system for ignition. This improvement is costly, makes the engine structure more complex, and increases the difficulty of later maintenance; the other is to preheat the methanol fuel, mostly through an external heater before it enters the engine. This improvement not only requires an additional preheating system, increasing engine manufacturing costs, but also has low heating efficiency, and due to the toxicity of methanol fuel, the consequences of a leak would be unimaginable. Regarding methanol leaks, existing improvements involve installing an inert gas purging layer in the engine fuel supply line to inertize and purge leaked methanol in a timely manner. However, this improvement has low purging efficiency and cannot meet the requirements of high efficiency and safety.

[0005] Furthermore, the flowability of methanol fuel within the fuel supply pipeline is significantly affected by temperature. At lower temperatures, the viscosity of methanol fuel increases, and its flowability decreases, potentially leading to incomplete purging. By increasing the pipeline temperature (typically between 20°C and 40°C), good flowability of methanol fuel is maintained, nitrogen purging efficiency is improved, and it is ensured that residual methanol and impurities within the pipeline are thoroughly removed. Technical issues

[0006] How to effectively improve the low-temperature cold start performance of methanol fuel engines, significantly reduce the risk of fuel splashing and leakage, and comprehensively improve the safety performance and methanol fuel purging efficiency of methanol fuel engines has become a key technical problem that needs to be solved by those skilled in the art. Technical solutions

[0007] The purpose of this invention is to provide a fuel supply system for a methanol fuel engine with a heating function, which effectively improves the low-temperature cold start performance of the methanol fuel engine.

[0008] This invention is achieved through the following technical solution:

[0009] A fuel supply piping system for a methanol fuel engine with heating function includes several three-layer pipes, adapter blocks for connecting the three-layer pipes, and limiting plates fixed at both ends of the adapter blocks. Each three-layer pipe includes an inner pipe, a middle pipe, an outer pipe, and two arc-shaped PTC heating plates. The inner pipe is a pipe with stepped flanges at both ends and an annular groove recessed in the middle. The two arc-shaped PTC heating plates are respectively embedded in the annular groove. The radial end faces of the arc-shaped PTC heating plates are limited by axial limiting strips symmetrically arranged on the outer circumference of the inner pipe. The inner pipe is inserted into the middle pipe. The stepped flanges at both ends of the inner pipe are threaded to the two ends of the inner hole of the middle pipe and are coated with sealant. An annular cavity with closed ends is provided between the outer circumference of the arc-shaped PTC heating plates and the inner hole of the middle pipe. Two pairs of outwardly extending protrusions are arranged radially at intervals on the upper and lower sides of the outer circumference of the middle pipe. The middle tube is inserted into the outer tube and sealed by the O-ring of the outer protrusion embedded in the top surface of the outer protrusion. The two ends of the outer tube are respectively provided with outer tube flanges. The connecting screws pass through the outer tube and are screwed into the corresponding outer protrusions to fix the outer tube and the middle tube into a whole. An outer tube annular cavity, which serves as a nitrogen channel, is provided between the inner hole of the outer tube and the outer circumferential surface of the middle tube. The two ends of the three-layer tube are respectively inserted into one end of the corresponding adapter block. The limiting plates are respectively positioned on the end of the outer tube and fixed on the vertical end face of the corresponding adapter block, thereby fixing several three-layer tubes into a whole pipe system through the adapter block and the limiting plate. The methanol injector oil pipe joint is fixed on the adapter block. The central hole of the adapter block is connected to the inner tube, which serves as the methanol fuel channel. The adapter blocks at both ends of the fuel supply pipe system are connected to the methanol station and the nitrogen station respectively through the corresponding double-walled pipes.

[0010] The objectives of this invention can also be further achieved through the following technical measures.

[0011] Furthermore, the adapter block is a cube. At the center of the vertical end faces at both ends of the adapter block, there are annular grooves with an inner diameter larger than the central hole of the adapter block. Positioning tubes extend outward from the central axis of each annular groove, with an inner diameter larger than the central hole diameter of the adapter block. At the center of the two apex inclined surfaces of the adapter block, there are threaded holes for the injector oil pipe connector and a pressure regulator valve, respectively. The inner ends of the threaded holes for the injector oil pipe connector and the pressure regulator valve intersect perpendicularly with the central hole of the adapter block. Multiple transverse holes are distributed on the bottom surface of the annular grooves, with both ends of each transverse hole penetrating the bottom surface of the annular groove and the outer surface of the outer surface. The tube has an annular cavity. When the two ends of the adapter block are connected to the corresponding ends of the three-layer tubes, the positioning round tubes are embedded in the annular grooves of the stepped flange end faces of the corresponding inner tube ends. The ends of the outer tube, middle tube, and inner tube abut against the bottom surface of the corresponding annular groove, so that the two ends of the three-layer tubes are positioned in the corresponding vertical end faces of the adapter block. The two ends of the multiple transverse holes are connected to the annular cavity of the outer tube of the three-layer tubes, and the central hole of the adapter block is connected to the inner tube. The ends of the outer tubes are inserted into the annular grooves, and the limiting plates are fixed on the corresponding vertical end faces of the adapter block, thereby fixing the three-layer tubes into an integral structure through the adapter block.

[0012] Furthermore, the limiting plate is formed by joining two half limiting plates together. The adjacent sides of the half limiting plates are respectively provided with semi-circular notches matching the circumference of the outer tube flange. The semi-circular notches are radially provided with semi-circular positioning grooves, and the outer tube flange is respectively provided with radially extending positioning ring ribs. When the two half limiting plates are positioned on the outer tube flange, the positioning ring ribs are respectively embedded in the corresponding semi-circular positioning grooves, the semi-circular notches abut against the outer circumference of the outer tube flange, and the fastening screws pass through the four corners of the limiting plate formed by splicing the two half limiting plates and are screwed into the vertical end face of the corresponding adapter block, thereby fixing the two ends of multiple three-layer pipes together into a pipe system with an integral structure through the adapter block and the limiting plate respectively.

[0013] Furthermore, the power cord at the end of the arc-shaped PTC heating plate passes through one end of the annular cavity of the middle tube and then leads to the outside of the outer tube through a connecting pipe; the inner end of the connecting pipe passes through the outer tube and the middle tube in sequence and is welded to the outer tube; the inside of the connecting pipe is sealed with sealant, and the outer end of the connecting pipe is sealed with a screw cap; the power cord is led out from the center hole of the screw cap.

[0014] Furthermore, two inner tube radial O-rings are installed in the annular groove on the stepped flange end face, and the positioning round tubes are respectively inserted into the annular grooves on the stepped flange end face of the corresponding inner tube end; the stepped flange end face is equipped with an inner tube axial O-ring, and the outer tube end is equipped with an outer tube radial O-ring. Beneficial effects

[0015] This invention employs a three-layered pipe system—inner, middle, and outer pipes—assembled as a fuel supply pipe for a methanol fuel engine. Two arc-shaped PTC heating plates are embedded in an annular groove in the middle of the inner pipe. When energized, the arc-shaped PTC heating plates instantly heat the methanol fuel in the inner pipe to 40°C within 3 seconds, eliminating the need for an external auxiliary fuel tank, an additional fuel injection system for ignition, or an external heater to preheat the methanol fuel before feeding it into the engine. The structure is compact, highly reliable, and significantly reduces the manufacturing cost of the methanol fuel engine. By using the arc-shaped PTC heating plates to heat the methanol fuel in the inner pipe, the low-temperature cold-start performance of the methanol fuel engine is effectively improved, comprehensively enhancing its safety performance and methanol fuel purging efficiency.

[0016] The advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments, which are given by way of example only with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1 is a three-dimensional structural diagram of the present invention;

[0018] Figure 2 is a front view of the present invention;

[0019] Figure 3 is an enlarged sectional view of Figure 2 (AA).

[0020] Figure 4 is an enlarged 3D view of the adapter block;

[0021] Figure 5 is a BB cross-sectional view of Figure 3;

[0022] Figure 6 is a view from direction C in Figure 4;

[0023] Figure 7 is a DD cross-sectional view of Figure 6;

[0024] Figure 8 is a front view of the limiting plate;

[0025] Figure 9 is an enlarged cross-sectional view of EE in Figure 2. Embodiments of the present invention

[0026] The invention will be further described below with reference to the accompanying drawings and embodiments of a methanol-fueled 6-cylinder engine.

[0027] As shown in Figures 1 to 9, this embodiment includes five three-layer tubes 1, adapter blocks 2 for connecting the three-layer tubes 1, and limiting plates 3 fixed at both ends of the adapter blocks. The three-layer tube 1 includes an inner tube 11, a middle tube 12, an outer tube 13, and two arc-shaped PTC heating plates 14. The inner tube 11 is a tube with stepped flanges 111 at both ends and an annular groove 112 recessed in the middle. The two arc-shaped PTC heating plates 14 are respectively embedded in the annular groove 112. The radial end faces of the arc-shaped PTC heating plates 14 are respectively limited by axial limiting strips 114 symmetrically arranged on the outer circumference of the inner tube 11. The inner tube 11 is inserted into the middle tube 12. The stepped flanges 111 at both ends of the inner tube are threaded to the inner ends of the middle tube 12 and are coated with sealant. An annular cavity 121 with closed ends is provided between the outer circumference of the arc-shaped PTC heating plate 14 and the inner end of the middle tube 12. The arc-shaped PTC heating plate can instantly heat the methanol fuel in the inner tube to 40°C in 3 seconds after being powered on.

[0028] As shown in Figure 3, two pairs of outwardly extending protrusions 122 are arranged radially and spaced apart on the outer circumferential surface of the middle tube 12. The middle tube 12 is inserted into the outer tube 13 and sealed by an O-ring 123 embedded in the top surface of the protrusions 122. The two ends of the outer tube 13 are respectively provided with outer tube flanges 131. Connecting screws 4 are screwed into the corresponding protrusions 122 through the outer tube 13, thus fixing the outer tube 13 and the middle tube 12 together. An annular cavity 132, serving as a nitrogen gas passage, is provided between the inner hole of the outer tube 13 and the outer circumferential surface of the middle tube 14.

[0029] As shown in Figures 4-7, the adapter block 2 is a cube. At the center of the vertical end faces at both ends of the adapter block, there are annular grooves 22 with an inner diameter larger than the diameter of the central hole 21 of the adapter block. Positioning tubes 221 extend outward from the center axis of the annular grooves 22, and the inner diameter of the positioning tubes 221 is larger than the diameter of the central hole 21 of the adapter block. At the center of the two apex inclined surfaces of the adapter block 2, there are threaded holes 23 for the methanol injector oil pipe connector and threaded holes 24 for the pressure regulator valve. The inner ends of the threaded holes 23 and 24 intersect perpendicularly with the central hole 21 of the adapter block. One end of the pressure regulator valve is screwed onto the threaded hole 24. When the methanol fuel engine experiences pressure fluctuations due to load changes, the pressure regulator valve can stabilize the pressure fluctuations in the inner tube 11. Multiple transverse holes 222 are distributed on the bottom surface of the annular grooves 22, with both ends of the transverse holes 222 penetrating the bottom surface of the annular grooves 22 and the annular cavity 132 of the outer tube, respectively. When the two ends of the adapter block 2 are connected to the corresponding ends of the three-layer pipe, the positioning round tubes 221 are respectively embedded in the stepped flange annular grooves 113 on the end face of the stepped flange 111 of the corresponding inner tube 11. The ends of the outer tube 13, the middle tube 12, and the inner tube 11 respectively abut against the bottom surface of the corresponding annular grooves 22, so that the two ends of the three-layer pipe are respectively positioned in the vertical end faces of the adapter block 2. Since the two ends of the multiple transverse holes 222 are respectively connected to the annular cavity 132 of the outer tube of the three-layer pipe, an outer nitrogen channel is provided for the three-layer pipe. The central hole 21 of the adapter block is connected to the inner tube 11, providing a central methanol fuel channel for the three-layer pipe.

[0030] As shown in Figures 3 and 8, the limiting plate 3 is formed by joining two half-limiting plates 31 together. Adjacent sides of the half-limiting plates 31 are provided with matching semi-circular notches 311 on the circumference of the outer tube flange 131. The semi-circular notches 311 are radially provided with semi-circular positioning grooves 312, and the outer tube flange 131 is provided with radially extending positioning ring ribs 133. When the two half-limiting plates 31 are positioned on the outer tube flange 131, the positioning ring ribs 133 are respectively embedded in the corresponding semi-circular positioning grooves 312, and the semi-circular notches 311 abut against the outer circumference of the outer tube flange 131. The fastening screws 5 pass through the four corners of the limiting plate 3 formed by the splicing of the two half-limiting plates 31 and are screwed into the vertical end face of the corresponding adapter block 2, thereby connecting multiple three-layer pipes into a unified pipe system via the adapter block 2 and the limiting plate 3.

[0031] The methanol injector oil pipe connector 6 is fixed on the adapter block 2. The central hole 21 of the adapter block is connected to the inner pipe 11, which serves as the methanol fuel passage. The adapter blocks 2 at both ends of the fuel supply pipeline connected to the methanol injector oil pipe connector 6 are respectively connected to the methanol station and the nitrogen station through corresponding double-walled pipes. The methanol injector oil pipe connector 6 leads to the methanol injectors of each cylinder of the methanol fuel engine through the methanol injector oil pipe, injecting methanol fuel into each cylinder for combustion and power generation, ensuring the normal operation of the methanol fuel engine.

[0032] As shown in Figures 2, 3 and 9, the power cord 124 at the end of the arc-shaped PTC heating plate 14 passes through the left end of the annular cavity 132 of the middle tube and then leads to the outside of the outer tube 13 through the connecting pipe 7; the inner end of the connecting pipe 7 passes through the outer tube 13 and the middle tube 12 in sequence and is welded to the outer tube 13 respectively; the inside of the connecting pipe 7 is sealed with sealant 71; the outer end of the connecting pipe 7 is sealed with a screw cap 72; and the power cord 124 is led out from the center hole of the screw cap 72.

[0033] As shown in Figure 3, two radial O-rings 114 are installed in the stepped flange annular groove 113 on the end face of the stepped flange 111, and an axial O-ring 115 is installed on the end face of the stepped flange 111, effectively preventing nitrogen gas from entering the inner tube 11 from the annular cavity 132 of the middle tube. An outer radial O-ring 134 is installed at the end of the outer tube to seal the methanol fuel in the inner tube 11, preventing leakage and ensuring the safe use of this invention.

[0034] In addition to the above embodiments, the present invention may have other implementation methods. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A fuel supply system for a methanol fuel engine with heating function, characterized in that: The device includes several three-layer tubes, adapter blocks for connecting the three-layer tubes, and limiting plates fixed at both ends of the adapter blocks. Each three-layer tube comprises an inner tube, a middle tube, an outer tube, and two arc-shaped PTC heating plates. The inner tube is a pipe with stepped flanges at both ends and an annular groove recessed in the middle. The two arc-shaped PTC heating plates are respectively embedded in the annular groove. The radial end faces of the arc-shaped PTC heating plates are limited by axial limiting strips symmetrically arranged on the outer circumference of the inner tube. The inner tube is inserted into the middle tube. The stepped flanges at both ends of the inner tube are threaded to the inner ends of the middle tube and coated with sealant. A closed-end annular cavity is provided between the outer circumference of the arc-shaped PTC heating plates and the inner hole of the middle tube. Two pairs of outwardly extending protrusions are arranged radially at intervals on the upper and lower sides of the outer circumference of the middle tube. The middle tube is inserted into the outer tube and... An O-ring seal is embedded in the top surface of the outer protrusion for sealing. The outer tube has flanges at both ends. Connecting screws pass through the outer tube and are screwed into the corresponding outer protrusions, fixing the outer tube and middle tube together. An annular cavity, serving as a nitrogen channel, is provided between the inner hole of the outer tube and the outer circumference of the middle tube. The two ends of the three-layer tube are inserted into one end of the corresponding adapter block. Limiting plates are positioned on the ends of the outer tube and fixed to the vertical end faces of the corresponding adapter blocks, thus connecting several three-layer tubes into a unified piping system via adapter blocks and limiting plates. The methanol injector oil pipe joints are fixed to the adapter blocks, and the central hole of the adapter block is connected to the inner tube, which serves as the methanol fuel channel. The adapter blocks at both ends of the fuel supply piping system are connected to the methanol station and nitrogen station via corresponding double-walled pipes.

2. The fuel supply system for a methanol fuel engine with heating function as described in claim 1, characterized in that: The adapter block is a cube. At the center of the vertical end faces at both ends of the adapter block, there are annular grooves with an inner diameter larger than the central hole of the adapter block. Positioning tubes extend outward from the central axis of each annular groove, with an inner diameter larger than the central hole diameter of the adapter block. At the center of the two apex inclined surfaces of the adapter block, there are threaded holes for the injector oil pipe connector and the pressure regulator valve, respectively. The inner ends of the threaded holes for the injector oil pipe connector and the pressure regulator valve intersect perpendicularly with the central hole of the adapter block. Multiple transverse holes are distributed on the bottom surface of the annular grooves, with both ends of each transverse hole penetrating the bottom surface of the annular groove and the annular cavity of the outer tube. When the two ends of the adapter block are connected to the corresponding ends of the three-layer tubes, the positioning round tubes are respectively embedded in the stepped flange annular grooves of the stepped flange end faces of the corresponding inner tube ends. The ends of the outer tube, middle tube, and inner tube abut against the bottom surface of the corresponding annular groove, so that the two ends of the three-layer tubes are respectively positioned in the corresponding vertical end faces of the adapter block. The two ends of the multiple transverse holes are respectively connected to the annular cavity of the outer tube of the three-layer tube, and the central hole of the adapter block is connected to the inner tube. The ends of the outer tubes are respectively inserted into the annular grooves, and the limiting plates are respectively fixed on the vertical end faces of the corresponding adapter blocks, thereby fixing the three-layer tubes into an integral structure through the adapter blocks.

3. The fuel supply system for a methanol fuel engine with heating function as described in claim 1, characterized in that: The limiting plate is formed by joining two half limiting plates together. The adjacent sides of the half limiting plates are respectively provided with semi-circular notches that match the circumference of the outer tube flange. The semi-circular notches are radially provided with semi-circular positioning grooves. The outer tube flange is respectively provided with radially extending positioning ring ribs. When the two half limiting plates are positioned on the outer tube flange, the positioning ring ribs are respectively embedded in the corresponding semi-circular positioning grooves. The semi-circular notches abut against the outer circumference of the outer tube flange. The fastening screws pass through the four corners of the limiting plate formed by splicing the two half limiting plates and are screwed into the vertical end face of the corresponding adapter block, thereby fixing the two ends of multiple three-layer pipes together into a pipe system with an integral structure through the adapter block and the limiting plate respectively.

4. The fuel supply system for a methanol fuel engine with heating function as described in claim 1, characterized in that: The power cord at the end of the arc-shaped PTC heating plate passes through one end of the annular cavity of the middle tube and then leads to the outside of the outer tube through a connecting pipe. The inner end of the connecting pipe passes through the outer tube and the middle tube in sequence and is welded to the outer tube. The inside of the connecting pipe is sealed with sealant, and the outer end of the connecting pipe is sealed with a screw cap. The power cord is led out from the center hole of the screw cap.

5. The fuel supply system for a methanol fuel engine with heating function as described in claim 2, characterized in that: Two radial O-rings for the inner tube are installed in the annular groove on the stepped flange end face. The positioning round tubes are respectively inserted into the annular grooves on the stepped flange end face of the corresponding inner tube end. The stepped flange end face is equipped with an axial O-ring for the inner tube, and the outer tube end is equipped with a radial O-ring for the outer tube.

Images