Safety system for combustion engines using low flashpoint fuels

Abstract

The invention discloses a safety system (4) for a combustion engine (2', 2") utilizing a low flashpoint fuel, the system comprising: a cover (8) arranged to be positioned near the engine to create a low-pressure environment around the engine, the cover configured to generate sufficient low pressure (15) to draw in air from around the engine; an inlet conduit (14) connecting the cover to the engine's air intake (20), configured to maintain the low-pressure environment and direct the fuel vapour-contaminated air into the air intake; a fuel sensor (12) arranged to monitor the concentration levels of fuel vapor (3) in the inlet conduit (14) due to low flashpoint fuel leaking from the engine; wherein the fuel sensor is configured to detect when a threshold concentration of fuel vapor in the inlet conduit is exceeded and to trigger a control response to cut off a fuel line supplying the low flashpoint fuel to the engine.

Description

[0001] Title: Safety system for combustion engines using low flashpoint fuels

[0002] Description:

[0003] TECHNICAL FIELD

[0004] The present invention generally relates to safety systems for combustion engines and, more particularly, to systems for managing and detecting fuel leaks in combustion engines operating with low flashpoint fuels such as methanol and ethanol. The invention addresses methods for actively controlling and monitoring fuel leaks to prevent hazardous conditions.

[0005] BACKGROUND

[0006] Combustion engines powered by fuels such as toxic or low flashpoint fuels, like methanol and ethanol, are widely used in applications that demand renewable fuels and low emissions, including industrial and marine applications. These fuels are characterized by their ability to ignite at relatively low temperatures, yet also posing increased safety risks, particularly when leaks occur in fuel lines or around the engine. Even minor leaks of low flashpoint fuels can result in hazardous vapor buildup, creating the potential for fire or explosion if these vapors are not promptly detected and managed.

[0007] Traditional leak management systems for such fuels often rely on double-walled fuel lines or other passive containment methods, which, while providing some degree of protection, can be unpracticle and expensive, in capturing and controlling vapor leaks from complex engine assemblies. Additionally, passive systems may not respond immediately to leaks, allowing hazardous vapor concentrations to accumulate. Furthermore, the compact nature of many engine installations restricts the use of extensive containment methods, which can hinder access to essential engine components and compromise overall engine performance.

[0008] Current advancements have sought to improve leak detection by using low-pressure or vacuum systems to draw leaked vapor toward a central collection pointfor monitoring. However, existing solutions often depend on external mechanisms, systems and devices such as airflow systems or compressors to create this low-pressure environment. A major drawback, especially in marine applications, is the need to safely discharge extracted air containing methanol vapors, often requiring impractical and expensive measures like installing masts on ships. These systems may also fail to maintain a controlled low-pressure environment when the engine is idle or operating at low speeds, leading to delays in detecting hazardous fuel vapor buildup. Consequently, there is a need for an active and responsive safety system capable of creating and maintaining a controlled low-pressure environment near the engine, to ensure constant detection and management of any fuel vapor leaks.

[0009] It is therefore a goal of the present invention to provide an improved safety system for combustion engines using low flashpoint fuels overcoming the above-mentioned disadvantages of the prior art at least in part.

[0010] SUMMARY OF THE INVENTION

[0011] One aspect of the present invention relates to a safety system for a combustion engine utilizing a fuels such as low flashpoint fuel and toxic fuels.

[0012] Low flashpoint fuels are defined as fuels that emit flammable vapors at temperatures below 60°C, requiring an external ignition source to ignite. These fuels, such as methanol, pose significant safety risks if leaks occur undetected, as their flammable vapors can easily ignite under operating conditions. While the present disclosure throughout the description focuses specifically on low flashpoint fuels, it is expressed that the system is also applicable to other fuels for wich such safety systems may be suitable, including toxic fuels. Throughout this disclosure, references to low flashpoint fuels should be understood to encompass any other relevant fuels, provided they fall within the scope of the invention, while explicitly excluding confusion with low auto-ignition temperature fuels.

[0013] A safety system may be understood as a protective arrangement for monitoring, managing, and mitigating risks associated with the operation of an engine, particularly risks that arise from fuel leaks. A combustion engine is a device designed to convert the chemical energy of fuel into mechanical energy by igniting the fuel-air mixture. A fuel refers to a low flashpoint fuel type that ignites at relatively lowtemperatures, such as approximalty 60 degrees Celsius, but also referes toxic fuels. Such fuels have increased risk of accidental ignition and hazards when leaks occur, making a robust safety system particularly relevant.

[0014] The system comprises a cover arranged to be positioned near the engine to create a low-pressure environment around the engine, the cover configured to generate sufficient low pressure to draw in air from around the engine. A cover is a structural component situated close to the engine, designed to form a space where the engine and any leaked fuel vapors can be monitored. The cover functions to create and maintain a controlled low-pressure environment, which serves to draw in and contain air that could be contaminated with fuel vapors. An effect of this arrangement is that it allows leaked fuel vapors to be directed toward a defined area, making it easier to manage and monitor vapor concentration levels effectively. This low-pressure environment helps prevent the escape of hazardous vapors, enhancing containment and enabling efficient monitoring of fuel vapor buildup near the engine.

[0015] The safety system further comprises an intake conduit connecting the cover to the engine’s air intake, configured to maintain the low-pressure environment and direct the air into the air intake. An intake conduit may be understood as a channel that transports air or vapors from one location to another. By connecting the cover to the engine's air intake, the intake conduit ensures that the low-pressure environment created around the engine is maintained. An effect of this configuration is the efficient direction of any fuel vapor-contaminated air toward the air intake for subsequent handling. By doing so, this arrangement allows for effective and consistent airflow management, promoting accurate monitoring of the area around the engine.

[0016] The system also comprises a fuel sensor arranged to monitor the concentration levels of fuel vapor in the intake air due to low flashpoint fuel leaking from the engine. A fuel sensor is a device capable of detecting and quantifying fuel vapor concentrations in the surrounding air. Positioned within the air intake pathway, the sensor constantly monitors for fuel vapor concentrations, ensuring prompt detection of any leaked fuel that may pose a risk. This arrangement allows for realtime monitoring of fuel vapor levels, which is critical to identifying potential hazards early and initiating preventive measures, as fuel vapor buildup can occur rapidly, especially with low flashpoint fuels.In the system, the fuel sensor is configured to detect when a threshold concentration of fuel vapor in the intake air is exceeded and to trigger a control response to cut off a fuel line supplying the low flashpoint fuel to the engine. The term threshold concentration refers to a pre-defined level of fuel vapor at which the risk becomes significant enough to warrant a response. The *control response* is an automatic action initiated by the system to prevent further hazards; in this case, it involves shutting off the fuel line that supplies fuel to the engine. By cutting off the fuel supply, this configuration effectively halts any further leakage, minimizing the risk of fire or explosion. This immediate cut-off response ensures that the system can take decisive preventive action as soon as a hazardous concentration of fuel vapor is detected, thereby enhancing the safety of the engine and surrounding environment.

[0017] In an example, the fuel sensor is positioned within the intake conduit. It may be provided that the fuel sensor is arranged within the intake conduit, where it is optimally placed to measure the concentration levels of fuel vapor in the air directed toward the engine intake. By positioning the fuel sensor directly within the intake conduit, this feature enables more accurate monitoring of fuel vapor levels close to the potential leak, enhancing detection precision and allowing prompt action in the event of a leak.

[0018] In an example, the cover includes a series of microchannels or small vents to facilitate the uniform distribution of airflow across the cover, enhancing the capture of fuel vapor from multiple leak points around the engine. It may be provided that the cover is structured with microchannels, which distribute the incoming airflow more evenly across the surface of the cover. These microchannels promote consistent airflow capture from multiple directions, facilitating an even distribution of air with potential fuel vapor contamination, which improves the overall capture rate and enhances the system's responsiveness to leaks.

[0019] In an example, the safety system further comprises a temperatureregulating device in thermal communication with the intake conduit, configured to maintain a stable temperature of the air entering the intake conduit to ensure consistent fuel vapor concentration measurements. It may be provided that the intake conduit is coupled with a temperature-regulating device to keep the air within a specified temperature range. This stable temperature condition allows the system to minimize variability in fuel vapor readings, providing reliable concentrationmeasurements unaffected by external temperature fluctuations, which could otherwise impact sensor accuracy.

[0020] In an example, the safety system further comprises a pressure regulator within the intake conduit, or at the air intake, configured to maintain a predetermined low pressure within the cover, irrespective of variations in ambient atmospheric pressure. It may be provided that a pressure regulator is integrated within the intake conduit to stabilize the low-pressure environment around the engine. This feature keeps the intake pressure consistent, even with changes in external atmospheric pressure, seal integrity of the cover, or engine setpoint, ensuring the low-pressure environment is stable and ready for effective vapor capture regardless of ambient conditions.

[0021] In an example, the cover is composed of a material with differing thermal expansion properties from the engine, the system further comprising an expansion compensator positioned between the cover and the engine to mitigate thermal stress effects that could otherwise impact the low-pressure environment. It may be provided that the cover material has distinct thermal expansion characteristics compared to the engine, with an expansion compensator installed to absorb the stress resulting from differential expansion. This compensator helps maintain the cover's position and integrity over a range of operating temperatures, ensuring that the low-pressure environment is unaffected by thermal shifts.

[0022] In an example, the safety system further comprises a filtration membrane positioned within the intake conduit, the membrane configured to allow only air and fuel vapor particles below a specified size range to pass through, preventing particulate matter from reaching the fuel sensor. It may be provided that a filtration membrane is installed in the intake conduit, allowing air and fuel vapor particles within a controlled size range to flow through while blocking larger particulate matter. By limiting particle size, this feature protects the sensor from contamination, improving the reliability and longevity of the monitoring system.

[0023] In an example, the safety system further comprises a control unit configured to process real-time vapor concentration data from the fuel sensor, the control unit programmed to compare detected vapor concentration fluctuations against a calibration profile associated with different leak sizes. It may be provided that a control unit is incorporated to analyze real-time data from the fuel sensor, withprogramming that matches observed fluctuations to a calibration profile. This feature allows the control unit to categorize and interpret varying leak sizes, enabling responsive measures appropriate to the leak’s severity.

[0024] In an example, the intake conduit incorporates a dual-compartment structure or a multi-compartment structure, separated by a vapor-impermeable partition, each compartment configured to convey air to different parts of the engine intake, and the fuel sensor is configured to detect differential vapor concentrations across the compartments for enhanced leak pinpointing. It may be provided that the intake conduit contains two or more compartments divided by a vapor-impermeable partition, each channeling air to distinct areas of the engine intake. The sensor detects differing vapor concentrations between these compartments, improving the system's ability to identify the location of a leak by comparing readings across the compartments, which is advantageous for isolating and addressing leaks precisely.

[0025] The skilled person will appreciate that the effects, advantages and examples discussed and disclosed in relation to the first aspect of the present disclosure are also applicable to other aspects of the present disclosure.

[0026] In an example, the fuel sensor is mounted externally to the intake conduit and connected via a precision capillary channel, the channel dimensioned to isolate the sensor from environmental temperature fluctuations and prevent interference with fuel vapor measurements. It may be provided that the fuel sensor is positioned directly into the intake conduit, or outside the intake conduit and linked to it through for example a precisely dimensioned capillary channel, allowing the sensor to avoid direct exposure to environmental temperature shifts. This arrangement isolates the sensor from ambient conditions, maintaining stable and reliable fuel vapor readings.

[0027] In an example, the intake conduit includes a bypass valve configured to divert airflow through an alternative pathway if the fuel vapor concentration exceeds the threshold level, allowing the system to prioritize air intake from uncontaminated areas. It may be provided that the intake conduit incorporates a bypass valve, which can redirect the airflow through an alternate path if vapor concentration reaches a critical threshold. By prioritizing air from less contaminated areas, this feature allows the system to manage air intake effectively, ensuring the engine receives a safer air mixture in case of elevated fuel vapor levels.In an example, the safety system further comprises a secondary detection mechanism integrated within the intake conduit, the secondary mechanism comprising a light-emitting diode (LED) and a photodetector to detect optical changes in the air stream as an additional indication of fuel vapor presence. It may be provided that a secondary detection mechanism, consisting of an LED and a photodetector, is positioned within the intake conduit to identify optical changes caused by fuel vapor in the air stream. This optical detection acts as a secondary verification of fuel vapor presence, improving system reliability by cross-verifying with the primary sensor.

[0028] In an example the intake conduit includes a chamber filled with an inert gas when the engine is idle, minimizing the risk of ignition within the enclosure in the event of a fuel leak. It may be provided that a chamber in the intake conduit is filled with an inert gas during idle periods, reducing the likelihood of ignition if fuel vapors are present. This arrangement ensures a safer environment under the cover when the engine is not operational, enhancing safety.

[0029] In an example, the cover includes a hydrophobic coating to prevent condensation within the enclosure and maintain optimal airflow conditions toward the intake conduit. It may be provided that the cover is treated with a hydrophobic coating that repels water, preventing condensation buildup in the enclosure. By minimizing moisture accumulation, this feature supports a clean and efficient airflow toward the intake conduit, reducing the risk of interference from water droplets.

[0030] In an example, the safety system further comprises a rapid-response shutoff valve connected to the fuel line, the valve configured to automatically close upon receiving a control signal from the fuel sensor when the threshold vapor concentration is exceeded. It may be provided that a rapid-response shutoff valve is integrated into the fuel line, closing automatically if vapor concentration reaches the threshold. This arrangement provides an immediate cut-off mechanism, effectively halting further fuel supply to prevent escalation of hazardous conditions.

[0031] In an example, the intake conduit further comprises a real-time data transmission module for continuous monitoring and reporting of vapor concentration data to a remote monitoring system. It may be provided that the intake conduit includes a real-time data transmission module to send continuous vapor concentration readings to an external monitoring system. This feature enables remote surveillance of fuel vapor levels, allowing for ongoing monitoring and proactive safety management.In an example, the safety system further comprises a programmable control unit configured to calculate the rate of vapor concentration increase based on sensor data, the control unit programmed to trigger graduated safety responses, including fuel line shutoff, alarm activation, and partial fuel flow restriction for leak containment. It may be provided that a programmable control unit calculates the rate of vapor concentration increase using data from the fuel sensor, adjusting safety responses based on the leak severity. This feature allows for a tiered safety response, ensuring appropriate action based on real-time risk assessment.

[0032] In an example, the system is configured for use with fuels selected rom a group consisting of toxic fuels, and low flashpoint fuels such as methanol, ethanol, and other alcohol-based fuels commonly used in industrial and marine applications. More in particular the system may be configured for petrol, propane, butane, LPG, methane, LNG, natural gas, ammonia, hydrogen, syngas, biogas and any suitable gas type fuel. It may be provided that the system is designed specifically for fuels with low flashpoints, such as methanol and ethanol, which are commonly used in specific industrial and marine settings. By focusing on these fuel types, this feature aligns the system’s design parameters with the demands of these fuels, ensuring effective performance in the intended environments.

[0033] In an example, the safety system further comprises an adjustable valve in the intake conduit, the adjustable valve configured to regulate the airflow between the cover and the engine’s air intake to maintain a stable low-pressure environment around the engine. It may be provided that an adjustable valve is incorporated within the intake conduit to control airflow levels. By regulating airflow dynamically, this feature ensures that a consistent low-pressure environment is maintained around the engine, allowing optimal capture and management of fuel vapor.

[0034] In an example, the system comprises an active underpressure generation means, configured to provide a controlled low-pressure environment under the cover independently of the engine’s air intake, thereby enhancing vapor capture even when the engine is idle. It may be provided that an active underpressure generation means is included to produce a controlled low-pressure environment around the engine without relying solely on the engine’s intake. This configuration ensures that vapor capture remains effective at all times, even when the engine is not running.In an example, the active underpressure generation means comprises a motorized pump configured to adjust the level of underpressure within the enclosure based on real-time measurements of fuel vapor concentration. It may be provided that the underpressure generation means includes a motorized pump, which adjusts the level of low pressure in real time according to the vapor concentration detected. By modulating pressure based on current vapor levels, this feature allows for responsive and precise control of the low-pressure environment, enhancing vapor management.

[0035] In an example, the control response includes an automated switch to an alternative fuel source upon detection of fuel vapor concentrations exceeding the threshold level, thereby allowing continued engine operation while preventing further leakage of the low flashpoint fuel. It may be provided that the control response includes an automatic switch to a secondary fuel source when the fuel vapor concentration surpasses the threshold. This feature enables the engine to continue running safely on an alternative fuel while isolating the low flashpoint fuel, minimizing operational disruption and addressing the detected leak in a controlled manner.

[0036] It will be understood that the above-described aspect, examples and embodiments are not meant to limit the invention, whose scope is solely determined by the appending claims. In particular, the skilled person will appreciate that various individual or combined features selected from various examples and embodiments within this description may be added to other examples and embodiments as long as there is no technical hindrance to doing so, without departing from the scope of the invention as defined by the claims.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The embodiments described herein will be more fully understood with the help of the detailed description below and with reference to the appended drawings, in which:

[0039] Fig. 1 illustrates a first embodiment of a safety system according to the present disclosure.

[0040] Fig. 2 illustrates a second embodiment of a safety system according to the present disclosure.DETAILED DESCRIPTION

[0041] The system provides a safety system for combustion engines operating with fuels such as toxicand low flashpoint fuels, addressing the critical issue of hazardous fuel vapor leaks that are prevalent when using fuels like methanol and ethanol. Existing solutions rely on passive containment methods, such as doublewalled systems, or external low-pressure environments created by ventilator, t, and they are impractical for compact engine installations due to increased complexity and cost. Leaks of low flashpoint fuels can lead to rapid accumulation of flammable vapors, creating conditions for fire or explosion if the vapors are not promptly managed. The present disclosure overcomes these limitations by providing an active safety system that continuously monitors fuel vapor concentration, generates a controlled low-pressure environment near the engine to capture leaked vapors, and triggers an immediate response, such as cutting off the fuel supply, when vapor levels exceed a predefined threshold. This results in enhanced safety, real-time monitoring, and effective containment of fuel vapors, irrespective of the engine’s operational state.

[0042] The system comprises a cover positioned near the engine to create a low-pressure environment around it. This cover is configured to draw in air and leaked fuel vapor from the area surrounding the engine. The cover is connected via an intake conduit to the engine's air intake, ensuring the captured air is directed into the intake system for monitoring. A fuel sensor is arranged to monitor the concentration of fuel vapors in the air entering the intake conduit. When the sensor detects that a predefined threshold concentration of fuel vapor is exceeded, a control response is triggered, cutting off the fuel line to the engine to halt the fuel supply and minimize further leakage. By creating and maintaining a controlled low-pressure environment independent of the engine's operating conditions, the system ensures that fuel vapor leaks are promptly captured and detected, even when the engine is idle. This insight effectively addresses the technical problems related to conventional, delayed or unreliable (vapor) leak detection seen in prior art systems, providing a surprising improvement that significantly enhances the safety of combustion engines operating with such fuels in a simplified and effect way.

[0043] In one embodiment, the safety system includes a cover surrounding the engine and configured to generate a low-pressure environment that captures leakedfuel vapors. The intake conduit connects this cover to the engine air intake, ensuring consistent airflow through the cover. A fuel sensor, positioned within the intake conduit, continuously monitors vapor concentration levels, measuring even minimal changes in the fuel vapor content. This sensor may include a high-sensitivity digital pressure transducer calibrated to detect fluctuations in vapor concentration specific to low flashpoint fuels. The system also features a control unit that processes real-time vapor concentration data from the sensor and triggers safety responses when a threshold level is exceeded. The control responses may include immediate fuel line shutoff, activation of alarms, or other safety protocols to mitigate the hazard.

[0044] A filtration membrane may be positioned within the intake conduit to prevent larger particulates from interfering with the fuel sensor, ensuring accurate vapor concentration measurements over time. For increased reliability, a secondary detection mechanism, such as an optical system comprising a light-emitting diode and a photodetector, can be integrated to detect optical changes caused by fuel vapors in the captured air.

[0045] Figure 1 shows a first embodiment T, illustrating a safety system 4 implemented with a V-configuration engine 2'. The engine cover 8 is positioned around the engine to create a low-pressure environment for capturing fuel leaks or fuel vapors 3 leaking from fuel-containing parts 6. The intake conduit 14 connects the engine cover to the engine air intake 20, ensuring that vapor-contaminated air is directed toward the engine intake for monitoring. A fuel sensor 12 is arranged within the intake conduit to monitor fuel vapor concentration levels. The fuel sensor communicates with a control unit, which triggers a safety response, such as cutting off the fuel supply, if the vapor concentration exceeds a predefined threshold. The system also includes a vacuum control valve 18 and an air filter 16 to manage airflow 15 and maintain stable pressure conditions and sufficient low pressure 15 within the cover.

[0046] Figure 2 illustrates a second embodiment of the invention applied to an in-line configuration engine 2". The safety system 4 operates similarly, with an engine cover 8 surrounding the engine to capture fuel vapors 3 leaking from fuel-containing parts 6. The intake conduit 14 connects the cover to the engine air intake 20, directing the captured air for monitoring. The fuel sensor 12, positioned within the intake conduit, measures vapor concentration and triggers a control response when a threshold level is exceeded. This embodiment demonstrates the adaptability of thesafety system for different engine configurations, ensuring consistent performance and vapor containment irrespective of the engine layout. The inclusion of features such as the pressure sensor 10 and vacuum control valve 18 further enhances system reliability and responsiveness.

[0047] The system provides significant advantages over conventional fuel vapor or leak detection systems by ensuring continuous monitoring and active containment of leaked vapors, in a simplified and effective way

[0048] Based on the above description, a skilled person may provide modifications and additions to the system, method and arrangement disclosed, which modifications and additions are all comprised by the scope of the appended claims.

Claims

CLAIMS1. A safety system (4) for a combustion engine (2’, 2”) utilizing a fuel, the system comprising:a cover (8) arranged to be positioned near the engine (2’, 2”) to create a low-pressure environment around the engine (2’, 2”), the cover (8) configured to generate sufficient low pressure (15) to draw in air from around the engine (2’, 2”);an intake conduit (14) connecting the cover (4) to the engine’s air intake (20), configured to maintain the low-pressure environment and direct the air into the air intake (20);a fuel sensor (12) arranged to monitor the concentration levels of fuel vapor in the intake air due to fuel leaking (3) from the engine;wherein the fuel sensor (12) is configured to detect when a threshold concentration of fuel vapor (3) in the intake air is exceeded and to trigger a control response to cut off a fuel line supplying the fuel to the engine (2’, 2”).

2. The safety system according to claim 1, wherein the fuel sensor is positioned within the intake conduit.

3. The safety system according to any of the previous claims, wherein the cover includes a series of microchannels to facilitate the uniform distribution of airflow across the cover, enhancing the capture of fuel vapor from multiple leak points around the engine.

4. The safety system according to any of the previous claims, further comprising a temperature-regulating device in thermal communication with the intake conduit, configured to maintain a stable temperature of the air entering the intake conduit to ensure consistent fuel vapor concentration measurements.

5. The safety system according to any of the previous claims, further comprising a pressure regulator within the intake conduit, configured to maintain a predetermined low pressure within the cover, irrespective of variations in ambient atmospheric pressure.

6. The safety system according to any of the previous claims, wherein the cover is composed of a material with differing thermal expansion properties from the engine, the system further comprising an expansion compensator positioned between the cover and the engine to mitigate thermal stress effects that could otherwise impact the low-pressure environment.

7. The safety system according to any of the previous claims, further comprising a filtration membrane positioned within the intake conduit, the membrane configured to allow only air and fuel vapor particles below a specified size range to pass through, preventing particulate matter from reaching the fuel sensor.

8. The safety system according to any of the previous claims, further comprising a control unit configured to process real-time vapor concentration data from the fuel sensor, the control unit programmed to compare detected vapor concentration fluctuations against a calibration profile associated with different leak sizes.

9. The safety system according to any of the previous claims, wherein the intake conduit incorporates a dual-compartment structure separated by a vapor-impermeable partition, each compartment configured to convey air to different parts of the engine intake, and the fuel sensor is configured to detect differential vapor concentrations across the compartments for enhanced leak pinpointing.

10. The safety system according to any of the previous claims, wherein the fuel sensor is mounted externally to the intake conduit and connected via a precision capillary channel, the channel dimensioned to isolate the sensor from environmental temperature fluctuations and prevent interference with fuel vapor measurements.

11. The safety system according to any of the previous claims, wherein the intake conduit includes a bypass valve configured to divert airflow through an alternative pathway if the fuel vapor concentration exceeds the threshold level, allowing the system to prioritize air intake from uncontaminated areas.

12. The safety system according to any of the previous claims, further comprising a secondary detection mechanism integrated within the intake conduit, the secondary mechanism comprising a light-emitting diode (LED) and a photodetector to detect optical changes in the air stream as an additional indication of fuel vapor presence.

13. The safety system according to any of the previous claims, wherein the intake conduit includes a chamber filled with an inert gas when the engine is idle, minimizing the risk of ignition within the enclosure in the event of a fuel leak.

14. The safety system according to claim 1, wherein the cover includes a hydrophobic coating to prevent condensation within the enclosure and maintain optimal airflow conditions toward the intake conduit.

15. The safety system according to any of the previous claims, further comprising a rapid-response shutoff valve connected to the fuel line, the valve configured to automatically close upon receiving a control signal from the fuel sensor when the threshold vapor concentration is exceeded.

16. The safety system according to any of the previous claims, wherein the intake conduit further comprises a real-time data transmission module for continuous monitoring and reporting of vapor concentration data to a remote monitoring system.

17. The safety system according to any of the previous claims, further comprising a programmable control unit configured to calculate the rate of vapor concentration increase based on sensor data, the control unit programmed to trigger graduated safety responses, including fuel line shutoff, alarm activation, and partial fuel flow restriction for leak containment.

18. The safety system according to any of the previous claims, wherein the system is configured for use with fuels selected rom a group consisting of toxic fuels, and low flashpoint fuels such as methanol, ethanol, and other alcohol-based fuels commonly used in industrial and marine applications.

19. The safety system according to any of the previous claims, further comprising an adjustable valve in the intake conduit, the adjustable valve configured to regulate the airflow between the cover and the engine’s air intake to maintain a stable low-pressure environment around the engine.

20. The safety system according to any of the previous claims, wherein the system comprises an active underpressure generation means, configured to provide a controlled low-pressure environment under the cover independently of the engine’s air intake, thereby enhancing vapor capture even when the engine is idle.

21. The safety system according to claim 20, wherein the active underpressure generation means comprises a motorized pump configured to adjust the level of underpressure within the enclosure based on real-time measurements of fuel vapor concentration.

22. The safety system according to any of the previous claims, wherein the control response includes an automated switch to an alternative fuel source upon detection of fuel vapor concentrations exceeding the threshold level, thereby allowing continued engine operation while preventing further leakage of the low flashpoint fuel.

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