A methanol tank pressure equalization system

Abstract

The utility model relates to a kind of methanol tank inner pressure balance system, solve the problem of the pressure difference of main and auxiliary methanol tank inconsistency. Including main methanol tank, auxiliary methanol tank and carbon tank, main methanol tank, auxiliary methanol tank bottom is connected in series by pipeline, main methanol tank top is equipped with methanol liquid level sensor and main methanol tank liquid level sensing breather valve, auxiliary methanol tank top is equipped with auxiliary methanol tank liquid level sensing breather valve, the connecting pipeline between main methanol tank liquid level sensing breather valve, auxiliary methanol tank liquid level sensing breather valve is sequentially connected with pressure regulating valve, pressurizing aeration pump and pressure sensing control valve a, pressure sensing control valve a is connected by pipeline and carbon tank's methanol steam inlet, connecting pipeline is connected with pressure sensing control valve b, carbon tank is also equipped with methanol steam outlet, atmospheric aeration port.The utility model prevents the risk of directly discharging methanol gas to atmosphere to pollute environment, maximum limit reduces the working intensity of methanol pump, increases the life of methanol pump and oil quantity sensor.

Description

Technical Field

[0001] This utility model relates to a methanol tank internal pressure balance system, belonging to the field of methanol truck fuel systems. Background Technology

[0002] Currently, the methanol truck industry faces the following problems with its fuel system:

[0003] 1. In series-tank methanol vehicles, the liquid levels on both sides of the main and auxiliary fuel tanks are not uniform. Methanol from the auxiliary tank can only flow into the main tank after the main tank's methanol is depleted. This is because the siphon principle prevents methanol fuel from flowing into the auxiliary tank in a timely manner, primarily due to the pressure difference between the main and auxiliary tanks.

[0004] 2. Most diesel and gasoline vehicles have a breather valve in their fuel tanks, but methanol gas is toxic, and laws and regulations do not allow excess methanol gas to be directly emitted into the atmosphere.

[0005] 3. If the fuel supply is insufficient during the journey, it will be difficult for the methanol fuel in the auxiliary methanol tank to flow into the auxiliary methanol tank, and the methanol level sensor will not be able to draw methanol fuel during the journey.

[0006] 4. Methanol is volatile and easily evaporates into gas at room temperature and pressure. It is prone to deterioration if left in a fuel tank for a long time. Utility Model Content

[0007] The purpose of this invention is to provide a methanol tank internal pressure balancing system. Utilizing a connected principle, it ensures consistent pressure difference between the main and auxiliary methanol tanks, preventing discrepancies in tank levels and eliminating the risk of direct methanol gas emission into the atmosphere and environmental pollution. It also solves the emergency problem of methanol sensors failing to draw fuel on the road, minimizing the workload of the methanol pump. The pressure difference principle ensures smoother methanol pumping, increasing the lifespan of the methanol pump and the fuel level sensor (a component supplying fuel in the engine fuel system).

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

[0009] A methanol tank internal pressure balancing system includes a main methanol tank 6, a secondary methanol tank 7, and a carbon tank 12. The bottoms of the main methanol tank 6 and the secondary methanol tank 7 are connected in series via pipelines. A methanol level sensor 2 and a main methanol tank level sensing breather valve 3 are installed above the main methanol tank 6. A secondary methanol tank level sensing breather valve 5 is installed above the secondary methanol tank 7. A pressure regulating valve 8, a pressurizing venting pump 9, and a pressure sensing control valve a10 are sequentially connected on the connecting pipeline between the main methanol tank level sensing breather valve 3 and the secondary methanol tank level sensing breather valve 5. The pressure sensing control valve a10 is connected to the methanol vapor inlet 122 of the carbon tank 12 via a pipeline. A pressure sensing control valve b11 is connected to the connecting pipeline. The carbon tank 12 is also provided with a methanol vapor outlet 123 and an atmospheric vent 121.

[0010] The pressure sensing control valve b10 is positioned at least 25mm above the upper surface of the fuel tank.

[0011] The main methanol tank 6 includes a main chamber 601 containing methanol and a secondary chamber 602 containing gasoline. A gasoline level sensor 1 and a gasoline level sensing breather valve 4 are installed on the secondary chamber 602.

[0012] The gasoline level sensing breather valve 4 is connected to the carbon canister 12 via a pipeline.

[0013] A pressure-sensing control valve is connected to the pipeline connecting the gasoline level sensing breather valve 4 and the carbon canister 12.

[0014] This invention employs a series connection of a pressurized venting pump, a pressure-sensing control valve, and a pressure regulating valve to balance the pressure within the methanol tank, ensuring smoother fuel supply. If the fuel level sensor fails to draw fuel during operation, this system can be used to pressurize the system and raise the methanol level. This system also controls methanol evaporation, increasing the fuel's shelf life. Ultimately, this ensures vehicle reliability, saves on transportation costs, and extends driving range. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] In the diagram, 1 is a gasoline level sensor (pumping gasoline); 2 is a methanol level sensor (pumping methanol); 3 is a main methanol tank level sensor breather valve; 4 is a gasoline level sensor breather valve; 5 is a secondary methanol tank level sensor breather valve; 6 is a main methanol tank (including main chamber 601 and secondary chamber 602); 7 is a secondary methanol tank; 8 is a pressure regulating valve; 9 is a pressurization vent pump (with both venting and pressurization states); 10 is a pressure sensor control valve a; 11 is a pressure sensor control valve b; 12 is a carbon canister (121 atmospheric vent—connected to the atmosphere, 122 fuel tank connection). Interface—Methanol vapor inlet, 123 Carbon canister solenoid valve connection port—Methanol vapor outlet); 13 Main and auxiliary methanol series pipe; 14 Main methanol tank level sensor breather valve to pressure regulating valve pipe; 15 Pressure regulating valve to pressurizing vent pump pipe; 16 Pressurizing vent pump to pressure sensor control valve a pipe; 17 Pressure sensor control valve a to auxiliary methanol tank level sensor breather valve pipe; 18 Pressure regulating valve to pressure sensor control valve b pipe; 19 Pressure sensor control valve b to carbon canister pipe; 20 Carbon canister to engine intake manifold pipe. Detailed Implementation

[0017] like Figure 1 As shown, the principle of the methanol tank internal pressure balance system of this utility model is as follows: the pipeline is pressurized and ventilated by a pressurizing venting pump to balance the pressure between the pipelines, and the venting and the connection between the main and auxiliary methanol tanks are controlled by a pressure sensing control valve.

[0018] Methanol gas flows from the main methanol tank to the pressure regulating valve, which then branches into two paths:

[0019] First route: Pressure regulating valve 8 to pressurizing vent pump 9, methanol gas from pressurizing vent pump 9 to pressure sensing control valve a10, pressure sensing control valve a10 detects pressure (there will be a range when set: it can be controlled in the cab, mainly through the pressure of the pressure sensing control valve to control the liquid level difference between the main and auxiliary oil tanks) and continues to the auxiliary methanol tank 7.

[0020] The second route: from pressure regulating valve 8 to carbon canister 12. The three ports of carbon canister 12 are, in order, fuel tank connection port - methanol vapor inlet 122, carbon canister solenoid valve connection port - methanol vapor outlet 123, and atmospheric vent port 121 - connected to the atmosphere (to maintain the internal pressure balance of the carbon canister). The methanol vapor flowing into carbon canister 12 will be adsorbed by the carbon canister and finally flow into the engine intake manifold to balance the internal pressure of the main methanol fuel tank.

[0021] This system has three operating states:

[0022] a. When the engine is running and the methanol tank has a high amount of methanol fuel, the pressure sensor control valve b11 connected to the carbon canister 12 opens, the pressure sensor control valve a10 connected to the carbon canister 12 opens, all pipelines are open, and the air pressure will be released from the atmospheric vent 121 of the carbon canister 12 to keep the main and auxiliary methanol tanks and pipelines in a state of equilibrium with the external air pressure.

[0023] b. When the methanol fuel in the methanol tank is low, the pressure regulating valve 8 is closed at the connection to the main methanol tank 6 (if the fuel is consumed too quickly during driving, causing an excessive pressure difference between the main and auxiliary methanol tanks, the pressure regulating valve 8 and the pressure sensing control valve b11 will automatically open, allowing atmospheric pressure to be supplied through the atmospheric vent 121 of the carbon canister 12 to balance the system pressure), and the pressure sensing control valve a10 connected to the auxiliary methanol tank 7 will open, drawing air from the main methanol tank 6 through the pressurized air pump 9 and injecting it into the auxiliary methanol tank 7. Because the pressure in the main methanol tank 6 is low and the pressure in the auxiliary methanol tank 7 is high, the liquid at the bottom of the auxiliary methanol tank 7 will be forced into the main methanol tank.

[0024] c. In the initial static state, the pressurized vent pump 9, pressure sensing control valve a10, and pressure sensing control valve b11 in the methanol pipeline are not working but are in the closed state. During prolonged static operation, and under high temperature conditions, methanol vapor will be generated in the methanol tank. When the methanol vapor in the main and auxiliary methanol tanks reaches a certain pressure, the pipeline will become open, passing through the pressure regulating valve 8 and pressure sensing control valve b11, and is pushed into the carbon canister 12. When the pressure returns to normal, the components in the pipeline system return to their initial state, preventing methanol fuel from evaporating and failing over time. The carbon powder in the carbon canister 12 can adsorb the evaporated fuel vapors produced by the methanol and gasoline tanks. During engine operation, the negative pressure between the carbon canister and the intake manifold allows the evaporated fuel vapors adsorbed in the carbon powder to be removed and enter the intake manifold for combustion, thus preventing the evaporated methanol vapors generated in the methanol tank from entering the external environment. The evaporated fuel vapors adsorbed in the carbon powder in the carbon canister 12 ultimately flow into the engine intake manifold for combustion in the methanol engine via the carbon canister solenoid valve.

[0025] The function of the pressure regulating valve 8 is to balance the internal pressure of the methanol tank and the external atmospheric pressure. However, the main passage of the pressure regulating valve 8 is to control the liquid level difference between the main and auxiliary oil tanks. Therefore, the pressure relief valve will only open and enter the carbon canister when the pressure exceeds a certain range. The internal pressure of the main and auxiliary methanol tanks will be balanced through the methanol vapor inlet 122 and methanol vapor outlet 121 of the carbon canister.

[0026] The pressure sensor control valve b10 should be positioned at least 25mm above the top plane of the fuel tank (to avoid fuel clogging of the valve body). The valve body will be interlocked. If one of the pipelines malfunctions and exceeds a certain pressure (the pressure range is calculated and set during system design), all valves will automatically open and all pipelines will be depressurized.

[0027] The gasoline fuel vapor in the gasoline tank of the main methanol tank can be connected to the carbon canister 12 to mix with the methanol vapor for more complete combustion, or it can be connected to a separate breather valve for exhaust.

[0028] This utility model has the following features:

[0029] 1. It eliminates the risk of directly emitting methanol gas into the atmosphere and polluting the environment;

[0030] 2. Controlling the pressure difference in the fuel system makes the pumping of oil smoother, solves the problem of the liquid level difference between the main and auxiliary methanol tanks, and increases the life of the fuel quantity sensor;

[0031] 3. In case of a sudden shortage of methanol fuel on the road, resulting in a low liquid level and the fuel level sensor not being able to fully contact the methanol level in the main methanol tank, this system can be used as an emergency measure to allow the methanol stored in the auxiliary methanol tank to flow into the main methanol tank.

[0032] 4. Because methanol is volatile, continuous ventilation will cause the methanol fuel concentration to decrease. Using this system will control the volatilization of methanol and increase the storage time of methanol fuel.

[0033] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A methanol tank internal pressure balancing system, comprising a main methanol tank and a secondary methanol tank, characterized in that: It also includes a carbon canister, a main methanol tank, and a secondary methanol tank connected in series at the bottom via pipelines. A methanol level sensor and a main methanol tank level sensing breather valve are installed above the main methanol tank, and a secondary methanol tank level sensing breather valve is installed above the secondary methanol tank. A pressure regulating valve, a pressurizing venting pump, and a pressure sensing control valve a are sequentially connected on the connecting pipeline between the main methanol tank level sensing breather valve and the secondary methanol tank level sensing breather valve. Pressure sensing control valve a is connected to the methanol vapor inlet of the carbon canister via a pipeline, and a pressure sensing control valve b is connected to the connecting pipeline. The carbon canister is also equipped with a methanol vapor outlet and an atmospheric vent.

2. The methanol tank internal pressure balance system according to claim 1, characterized in that: The pressure sensing control valve b is positioned at least mm above the upper plane of the fuel tank.

3. The methanol tank internal pressure balance system according to claim 1, characterized in that: The main methanol tank includes a main chamber containing methanol and a secondary chamber containing gasoline. A gasoline level sensor and a gasoline level sensing breather valve are installed on the secondary chamber.

4. The methanol tank internal pressure balance system according to claim 3, characterized in that: The gasoline level sensing breather valve is connected to the carbon canister via a pipeline.

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