Condensate water prevention and control device and method for intake system of high-altitude octane rating machine

Abstract

The application discloses a high-altitude octane rating determination machine intake system condensate water prevention and control device and method, and belongs to the technical field of gasoline octane rating determination. The device comprises an intake cooling unit, a temperature fluctuation suppression unit and an active drainage unit. The intake cooling unit comprises a pre-cooler and a main cooler arranged in sequence along the airflow direction, the pre-cooler cooling medium temperature is set to-5 to 0 DEG C, and the main cooler cooling medium temperature is set to 0 to-2 DEG C; the temperature fluctuation suppression unit comprises a heater, a heat conduction plate with a specific heat capacity less than 0.4 J / (g*K) and a temperature sensor, and forms a cascade temperature control loop; the active drainage unit comprises a water collecting tank arranged at the lowest point of the pipeline 20-30 mm upstream of the fuel chamber and a drain valve. The application combines staged cooling, temperature fluctuation suppression and active drainage, effectively solves the problem that excessive condensate water in the high-altitude octane rating determination machine intake system causes ignition delay, and improves the precision and accuracy of the determination data.

Description

TECHNICAL FIELD

[0001] The present invention relates to the technical field of gasoline octane rating determination, and specifically relates to a device and method for preventing and controlling condensed water in an air intake system of an octane rating tester in high-altitude areas, which is particularly suitable for CFR octane rating testers in plateau areas with an altitude of 1500 meters or more and an atmospheric pressure lower than the standard atmospheric pressure. BACKGROUND ART

[0002] Research Octane Number (RON) is a core index for evaluating the antiknock performance of motor gasoline, and its accurate determination depends on the highly stable operation of a CFR octane rating tester. The GB / T 5487-2015 standard imposes extremely strict control requirements on the air intake state: the air intake temperature must be kept constant within the range specified by the standard, the air intake humidity needs to be controlled within the range of 3.58-7.16 grams per kilogram of air, and atmospheric pressure and humidity correction are required.

[0003] In the prior art, a CFR octane rating tester usually adopts an Ice Tower or a refrigerated air dehumidifier to cool and dehumidify intake air. For example, the Model 500 refrigerated air dehumidifier matched with the Waukesha CFR octane rating engine filters ambient air before it is drawn in by the CFR carburetor, cools the intake air to 1.5°C to 3.5°C through a refrigeration system, and condensed water is discharged to a floor drain through a plastic pipe. The device is also equipped with a digital temperature controller that can control the temperature of the liquid storage tank, with a temperature stability of up to ±0.5°C. In addition, US20120055151A1 discloses a drain valve for an engine air intake system, which is arranged at a condensed water collection position in the air intake system and can move between a closed position and an open position to discharge condensed water.

[0004] However, all the above prior arts have the following deficiencies:

[0005] (1) The physical mechanism that causes a significant increase in condensed water production in a high-altitude low-pressure environment is not fully considered. According to the thermodynamic principle of moist air, at a fixed temperature, the saturated moisture content is inversely proportional to the total atmospheric pressure. Calculations show that when 30°C saturated air is cooled to 5°C at a pressure of 81.0 kPa, about 28 grams of water vapor per kilogram of dry air condenses into liquid water, which is significantly higher than the amount of condensed water under the same working conditions at sea level. When the equipment operates in a high-altitude area (such as Anning, Yunnan, with an altitude of about 1900 meters and an average annual atmospheric pressure of about 81.0 kPa), the thermodynamic characteristics of the air intake system deviate significantly, and the prior art fails to carry out optimized design for this special working condition.

[0006] (2) There is a lack of collaborative design with the air intake temperature control system. In the prior art, although there are reports on condensed water discharge devices for engine air intake systems, the water discharge device and the temperature control system are independent of each other, and a systematic prevention and control solution has not been formed.

[0007] (3) It is impossible to effectively discharge condensate while ensuring the airtightness of the intake system and the accuracy of temperature control. Some existing technologies only set a drain outlet at the lowest point of the intake system, but do not consider the impact of the drain outlet location on the special structure of the octane number tester (such as the carburetor). In particular, the low point of the upstream pipeline of the carburetor is very prone to forming a "water seal" due to a small amount of water accumulation, which blocks the mixture from entering the cylinder.

[0008] (4) The design was not optimized for the special inlet temperature control requirements (constant between 4-5℃) of the octane number analyzer. Existing temperature control schemes focus on cooling efficiency but neglect the promoting effect of temperature fluctuations on the unsteady formation of condensate.

[0009] In particular, when CFR octane rating analyzers are running at high altitudes, a large amount of condensate flows slowly along the intake manifold wall under gravity, eventually accumulating and stagnating at the lowest point of the intake manifold—the connection upstream of the carburetor—forming a localized "water seal." This causes random ignition delays of varying durations during engine start-up, which can last from tens of seconds to several minutes in severe cases, or even prevent the engine from starting altogether. This fault occurs significantly more frequently during high humidity seasons, severely interfering with testing procedures and affecting the precision and accuracy of the measurement results. Summary of the Invention

[0010] The present invention aims to solve the above-mentioned problems existing in the prior art and provides a device and method for controlling condensate in the intake system of an octane number measuring machine in high-altitude areas. By combining cooling system optimization, temperature fluctuation suppression and active drainage, the device effectively controls condensate in the intake system and completely eliminates ignition delay faults caused by condensate accumulation.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] A device for controlling condensate in the intake system of an octane number measuring machine for high-altitude areas includes an intake cooling unit, a temperature fluctuation mitigation unit, and an active drainage unit.

[0013] The intake cooling unit includes a precooler and a main cooler arranged sequentially along the airflow direction. The precooler is located after the air filter, and its cooling area is 1.3 times that of the original cooler. The cooling medium temperature is set to -5°C to 0°C. The main cooler is located downstream of the heat-conducting plate and closer to the engine air intake. Its cooling medium temperature is set to 0°C to -2°C, used to precisely cool the air to the target temperature. Preferably, the precooler and the main cooler adopt a counter-flow heat exchange structure.

[0014] The temperature fluctuation suppression unit includes a heater installed inside the intake duct, a heat-conducting plate installed on the surface of the heater, and a temperature sensor. The heat-conducting plate is made of a metal material (such as aluminum alloy or copper alloy) with a specific heat capacity of less than 0.4 J / (g·K), and its surface area is 20%-30% larger than that of the original heater heat-conducting plate. The heater and the temperature sensor are associated to form a cascade temperature control loop, which is used to control the intake temperature fluctuation within ±0.5℃.

[0015] The active drainage unit includes a water collection tank, a drain pipe, and a drain valve. The water collection tank is located at the bottom of the air intake pipe, 20-30mm upstream of the carburetor chamber, and has a drain outlet at its bottom. One end of the drain pipe is connected to the drain outlet, and the other end is connected to an external receiving container. The drain valve is installed on the drain pipe. Preferably, the drain valve is a manual ball valve or a solenoid valve. The water collection tank is funnel-shaped, and a filter screen is installed at its bottom drain outlet. The air intake pipe has a transparent observation window at the water collection tank.

[0016] This invention also provides a method for controlling condensate in the intake system of an octane number analyzer in high-altitude areas, comprising the following steps:

[0017] Step 1, Staged Cooling: The ambient air is sequentially cooled through a precooler and a main cooler. The precooler initially cools the air to -5°C to 0°C, removing most of the high-temperature load. The main cooler precisely cools the air to the target temperature of 5±1°C.

[0018] Step 2: Smoothing Temperature Fluctuations: The heater power is adjusted via a cascade temperature control loop. A low-heat-capacity heat-conducting plate is used to quickly respond to temperature changes, controlling intake air temperature fluctuations within ±0.5℃, thus reducing fluctuations in condensate generation caused by drastic temperature changes. The cascade temperature control loop uses intake air temperature as the primary control parameter and heater power as the secondary control parameter. When the intake air temperature deviates from the set value, the heater power is adjusted first to compensate.

[0019] Step 3: Condensate collection: The condensate generated in the intake pipe is collected by gravity into a collection tank located at the lowest point of the pipe.

[0020] Step 4: Active Drainage: Before each test cycle begins, open the drain valve to drain the condensate accumulated in the collection tank. When using a solenoid valve as the drain valve, the controller will automatically open the solenoid valve for 2-5 seconds before each test cycle to drain the water; or visually inspect the water accumulation through the transparent observation window located in the collection tank, and manually open the drain valve to drain the water when obvious water accumulation is observed.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. Reducing condensate generation at the source: By employing a staged cooling design with a precooler and main cooler, the cooling area is increased by 30%, and the main cooler temperature is optimized from the conventional -25℃ to approximately -5℃ to 0℃. This reduces the temperature difference in single-stage cooling and decreases the amount of condensate generated due to rapid cooling. Theoretical calculations and practical applications show that this design can reduce condensate generation by approximately 30%. Compared to conventional -25℃ deep cooling (see Comparative Example 1), this invention can reduce condensate generation by approximately 80%, while also avoiding problems such as excessively low intake air humidity (below the standard lower limit of 3.58 g / kg) and heat exchanger frosting.

[0023] 2. Smoothing Temperature Fluctuations and Stabilizing Intake Air Conditions: By employing a low-heat-capacity heat transfer plate (specific heat capacity less than 0.4 J / (g·K)) and increasing the heat transfer surface area, coupled with a cascade temperature control loop, the temperature fluctuations of the air surrounding the heater are significantly reduced to within ±0.5℃. The stable intake air temperature reduces drastic humidity changes caused by temperature fluctuations, further suppressing the unsteady formation of condensate.

[0024] 3. Achieving proactive and controllable condensate drainage: A condensate collection tank and drain valve are installed at the lowest point of the intake pipe to proactively drain accumulated condensate before testing, preventing the formation of a "water seal" during startup. A transparent observation window at the condensate collection tank allows operators to visually inspect the condensate level, enabling visual monitoring. Compared to solutions that only place the condensate collection tank at the lowest geometric point of the pipe (see Comparative Example 2), this invention precisely positions the condensate collection tank at a fault-sensitive point 20-30mm upstream of the carburetor chamber, completely eliminating residual condensate at this local low point.

[0025] 4. Complete elimination of ignition delay fault: Through the above three measures, the accumulation of condensate in front of the carburetor, forming a "water seal," is effectively prevented, ensuring that the air-fuel mixture enters the cylinder normally during startup. Practical application shows that after adopting this device and method, the octane rating tester achieves a 100% startup success rate, and the ignition delay phenomenon completely disappears.

[0026] 5. Improved precision of measurement data: Due to the restoration of the stability of the intake state and the reliability of the combustion initialization process, the repeatability standard deviation of the octane number measurement data is far better than the requirements of GB / T 5487-2015 standard.

[0027] 6. Low modification cost and strong applicability: This invention can be modified based on the existing octane number analyzer without replacing the main unit. It is easy to install and maintain, and is especially suitable for mass application in laboratories in high-altitude areas. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the fuel system structure in an embodiment of the present invention.

[0029] Figure 2This is a schematic diagram of the condensate control device for the air intake system of the present invention.

[0030] Figure 3 This is a control logic block diagram of the temperature fluctuation suppression unit of the present invention.

[0031] Figure 1 In the middle: 101-Carburetor sump, 102-Float chamber, 103-Fuel selector valve, 104-Venturi tube, 105-Vertical nozzle, 106-Fuel level sight glass, 107-Intake pipe interface, 108-Engine air intake.

[0032] Figure 2 In the middle: 1-Air filter, 2-Ice tower, 3-Precooler, 4-Heater, 5-Heat plate, 6-Temperature sensor, 7-Water collection tank, 8-Main cooler, 9-Drain valve, 10-External receiving container, 11-Carburetor chamber, 12-Engine air intake. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0034] Example 1

[0035] 1. Device Structure

[0036] Reference Figure 2 A device for controlling condensate in the intake system of an octane number measuring machine for high-altitude areas, comprising an intake cooling unit, a temperature fluctuation mitigation unit, and an active drainage unit.

[0037] The intake cooling unit includes a precooler 3 and a main cooler 8 arranged sequentially along the airflow direction. The precooler 3 is located after the air filter 1, and its cooling area is 1.3 times that of the original cooler. The cooling medium temperature is set to -5℃ to 0℃, and it adopts a counter-flow heat exchange structure. The main cooler 8 is located downstream of the heat guide plate 5 and closer to the air intake 12 of the CFR engine. Its cooling medium temperature is set to 0℃ to -2℃, and it is used to precisely cool the air to the target temperature of 5±1℃.

[0038] Both the precooler 3 and the main cooler 8 adopt a tube-fin heat exchanger structure, and the cooling medium is an aqueous solution of ethylene glycol, which is provided by an external refrigeration unit for circulating cooling. The cooling coils of the precooler 3 are evenly arranged along the cross-section of the air inlet pipe, and the airflow direction is opposite to the flow direction of the cooling medium to form counter-current heat exchange, thereby improving the heat exchange efficiency.

[0039] The temperature fluctuation suppression unit includes a heater 4 installed inside the intake duct, a heat-conducting plate 5 installed on the surface of the heater, and a temperature sensor 6. The heat-conducting plate 5 is made of aluminum alloy with a specific heat capacity of 0.38 J / (g·K), and its surface area is 25% larger than that of the original heater's heat-conducting plate. The heater 4 and the temperature sensor 6 are connected to form a cascade temperature control loop. (Refer to...) Figure 3 The circuit uses intake air temperature as the primary control parameter and heater power as the secondary control parameter. When the intake air temperature deviates from the set value by 5℃, the heater power is adjusted first for rapid compensation, and the intake air temperature fluctuation is controlled within ±0.5℃.

[0040] The heater 4 is located in the air inlet pipe section between the precooler 3 and the main cooler 8, and adopts an electric heating tube structure with an adjustable heating power of 500W-1500W. The heat-conducting plate 5 is tightly attached to the heat dissipation surface of the heater 4, and its surface is evenly distributed with heat dissipation fins to increase the heat exchange area with the air inlet.

[0041] The active drainage unit includes a water collection tank 7, a drain pipe, and a drain valve 9. The water collection tank 7 is located at the lowest point of the intake pipe, 25mm upstream of the carburetor chamber 11, at the bottom of the pipe. This location is determined through actual observation as the main point of condensate accumulation. The water collection tank 7 is funnel-shaped with a drain outlet at its bottom, where a filter screen is installed. The water collection tank 7 is connected to the external receiving container 10 via a drain pipe, on which the drain valve 9 is installed. In this embodiment, the drain valve 9 is a manual ball valve. A transparent observation window is provided in the intake pipe at the water collection tank 7 for the operator to visually inspect the condensate accumulation.

[0042] The funnel-shaped structure of the water collection tank 7 has an inclined surface that gradually tapers from the bottom of the air inlet pipe to the drain outlet, with an inclination angle of 15°-30°, to facilitate the collection of condensate towards the drain outlet under gravity. A filter screen installed at the drain outlet prevents impurities or rust from entering the drain valve and causing blockage.

[0043] 2. Working Methods

[0044] The intake system condensate control method of this embodiment includes the following steps:

[0045] Step 1, Staged Cooling: After being filtered by air filter 1, ambient air first enters precooler 3. Precooler 3 initially cools the air to -5°C to 0°C, removing most of the high-temperature load and water vapor. The pre-cooled air then enters main cooler 8, which precisely cools the air to the target temperature of 5±1°C. By distributing the cooling load to the two-stage coolers, the temperature difference per stage is reduced from the conventional approximately 30°C to approximately 5-10°C, significantly reducing the rapid precipitation of condensate caused by rapid cooling.

[0046] Step 2: Smoothing Temperature Fluctuations: After being precisely cooled by the main cooler 8, the air flows through the heater 4 and the heat-conducting plate 5. The temperature sensor 6 monitors the intake air temperature in real time and feeds the signal back to the cascade temperature control loop. This loop uses intake air temperature as the primary control parameter and heater power as the secondary control parameter. When the intake air temperature deviates from the set value by 5℃, the heater power is adjusted first for rapid compensation. The heat-conducting plate 5 is made of low-heat-capacity aluminum alloy with a specific heat capacity of 0.38 J / (g·K), which responds quickly to temperature changes. Combined with cascade control, intake air temperature fluctuations can be controlled within ±0.5℃, reducing the formation of unstable condensate caused by drastic temperature fluctuations.

[0047] Step 3: Condensate Collection: After staged cooling and temperature stabilization, the condensate generated in the intake pipe flows downward along the pipe wall under gravity, eventually collecting in the water collection tank 7, located 25mm upstream of the lowest point of the pipe—the carburetor chamber 11. The funnel-shaped structure of the water collection tank 7 ensures that the condensate is concentrated towards the drain outlet, and the filter screen prevents impurities from entering the drain pipe.

[0048] Step 4, Active Drainage: Before each test cycle, the operator visually inspects the water accumulation in the water collection tank 7 through the transparent observation window. If significant water accumulation is observed, the operator manually opens the drain valve 9 to drain the accumulated condensate in the water collection tank 7 into the external receiving container 10 through the drain pipe. After drainage is complete, the drain valve 9 is closed, and the engine is started for testing.

[0049] Example 2

[0050] The difference between this embodiment and Embodiment 1 lies in the structure and control method of the drain valve.

[0051] like Figure 2 As shown, the drain valve 9 is a normally closed two-position two-way solenoid valve and is electrically connected to the controller. The controller is a programmable logic controller or an embedded microcontroller, and its output is connected to the coil drive circuit of the solenoid valve.

[0052] The controller is configured to automatically output an opening signal to control the solenoid valve to open for 3 seconds before the start of each test cycle (before engine start), using the slight positive pressure of the intake system to purge and discharge accumulated condensate to the external receiving container 10. After the solenoid valve has been open for 3 seconds, the controller outputs a closing signal, the solenoid valve resets to the normally closed state, and the engine can then be started.

[0053] As an alternative, the opening time of the solenoid valve can be adjusted within the range of 2-5 seconds according to the actual amount of water accumulated. During high humidity seasons or when the ambient humidity is high, the opening time can be extended to 5 seconds via the controller; during dry seasons, it can be shortened to 2 seconds.

[0054] The structure, connection relationship and working principle of the remaining components in this embodiment are the same as those in Embodiment 1.

[0055] Example 3

[0056] The difference between this embodiment and Embodiment 1 is that the key parameters are selected from the two extreme values ​​of the range, in order to verify the feasibility and effectiveness of the technical solution of the present invention under parameter boundary conditions.

[0057] 1. Parameter lower limit configuration

[0058] In this embodiment, the cooling medium temperature of the precooler 3 is set to -5℃, and the cooling medium temperature of the main cooler 8 is set to -2℃; the heat-conducting plate 5 is made of copper alloy material with a specific heat capacity of 0.39J / (g·K), and its surface area is increased by 20% compared with the original heater heat-conducting plate; the water collection tank 7 is located at the bottom of the pipe 20mm upstream of the carburetor chamber 11; the drain valve 9 is a manual ball valve.

[0059] Under the above parameter configuration, the cooling capacity of the precooler 3 is near the lower limit, and its initial cooling effect on the air is relatively weak. However, even with a larger cooling load, the main cooler 8 can still accurately cool the air to the target temperature range of 5±1℃. The water collection tank 7 can still effectively collect the condensate generated in the pipes and complete the collection and discharge 20mm upstream of the carburetor chamber. This configuration verifies the feasibility of the present invention under the boundary conditions of cooling capacity.

[0060] 2. Parameter upper limit configuration

[0061] In this embodiment, the cooling medium temperature of the precooler 3 is set to 0℃, and the cooling medium temperature of the main cooler 8 is set to 0℃; the heat conduction plate 5 is made of aluminum alloy material with a specific heat capacity of 0.38J / (g·K), and its surface area is 30% larger than that of the original heater heat conduction plate; the water collection tank 7 is located at the bottom of the pipe 30mm upstream of the carburetor chamber 11; the drain valve 9 is a normally closed two-position two-way solenoid valve, and the opening time is set to 5 seconds.

[0062] Under the above parameter configuration, the cooling medium temperature of precooler 3 is relatively high (0℃), providing only a slight precooling effect on the air. Main cooler 8 can still accurately cool the air to the target temperature range of 5±1℃ even at 0℃. The surface area of ​​the heat-conducting plate is increased by 30%, further improving the response speed to temperature fluctuations. The water collection tank 7 is located 30mm upstream of the carburetor chamber, providing a wider installation tolerance range, facilitating adjustments based on the specific pipeline routing during actual modifications. A 5-second opening time for the solenoid valve ensures that condensate accumulated under high humidity conditions is fully drained.

[0063] The structure, connection relationship and working principle of the remaining components in this embodiment are the same as those in Embodiment 1.

[0064] Application effect verification

[0065] The application effect of the device of the present invention was verified under conditions of an altitude of about 1900 meters and an average annual atmospheric pressure of about 81.0 kPa.

[0066] Temperature fluctuation mitigation effect: Before the modification, the main cooler temperature was -25℃; after the modification, using a low-heat-capacity heat-conducting plate and cascade control, the main cooler temperature stabilized within the range of -5℃ to 0℃, and the cooling capacity was significantly reduced. Data recorded by temperature sensor 6 shows that the intake air temperature fluctuation range after the modification is 4.8℃-5.2℃, which is controlled within ±0.2℃, better than the design target of ±0.5℃.

[0067] Condensate generation and drainage effect: Before the modification, 2-15 mL of water was visible accumulating at the lowest point of the intake pipe, with particularly severe accumulation during seasons with high humidity. After the modification, the staged cooling design reduced condensate generation by approximately 90%, and the active drainage unit completely drained any remaining water before each test, leaving no visible water in the pipes. 30 consecutive days of operation records showed that the amount of condensate accumulating in the water collection tank 7 was less than 1 mL per instance, and all condensate was effectively drained through the drain valve 9 before testing.

[0068] Start-up reliability: Before the modification, the octane number analyzer often experienced ignition delays during its first start-up in the morning, with delays ranging from several seconds to several minutes. After the modification, it successfully started on the first attempt in 100 consecutive start-up tests, achieving a 100% success rate, and the ignition delay phenomenon completely disappeared. Even in high humidity conditions with relative humidity exceeding 80%, the start-up remained smooth.

[0069] Precision of the measured data: Five consecutive repeatability tests were conducted using 92-octane and 95-octane gasoline samples. The average value for 92-octane gasoline was 92.5, and the average value for 95-octane gasoline was 95.6. The standard deviation of repeatability was less than 0.2, which is far superior to the repeatability limit required by GB / T 5487-2015 standard. The problem of abnormal fluctuations in measured data caused by unstable startup before the modification has been completely resolved.

[0070] Long-term operational stability: After 6 months of continuous operation and observation, all units of the present invention operated stably. The heat exchange efficiency of the precooler 3 and the main cooler 8 showed no significant decrease, the heat conduction plate 5 showed no deformation or corrosion, and the water collection tank 7 and drain valve 9 showed no blockage. Maintenance of the device only requires periodic cleaning of the filter screen at the drain outlet of the water collection tank 7, with a maintenance cycle of once every 3 months, making maintenance simple.

[0071] Comparative Example 1

[0072] To verify the non-obviousness of the main cooler temperature setting, Comparative Example 1 was set up.

[0073] The device structure of Comparative Example 1 is basically the same as that of Example 1, except that the cooling medium temperature of the precooler 3 is set to -25℃ and the cooling medium temperature of the main cooler 8 is set to -25℃ (i.e., a conventional single-stage deep cooling method is adopted). The other parameters and component structures are exactly the same as those of Example 1.

[0074] Comparative tests were conducted under identical conditions: an altitude of approximately 1900 meters, an average annual atmospheric pressure of approximately 81.0 kPa, an ambient temperature of 30℃, and a relative humidity of 70%. The results showed that in Comparative Example 1, although the outlet air temperature of the main cooler 8 could be stabilized at 5±1℃, the amount of condensate generated per test cycle reached 8-15 mL, and the inlet air humidity dropped to 2.8-3.2 g / kg, lower than the lower limit of 3.58 g / kg specified in GB / T 5487-2015. Simultaneously, significant frost formation appeared on the outer wall of the heat exchange tubes of the main cooler 8, requiring frequent defrosting. In the startup test, the first-time startup success rate was approximately 85%, with the remaining 15% of startups experiencing an ignition delay of 2-10 seconds.

[0075] In comparison, in Embodiment 1 of the present invention, the temperature of the precooler 3 is set to -5℃ to 0℃ and the temperature of the main cooler 8 is set to 0℃ to -2℃. The amount of condensate generated per test cycle is only 1-3mL, and the intake air humidity is 3.8-5.2g / kg, which meets the standard requirements. There is no frost phenomenon, and the start-up success rate is 100%.

[0076] The above comparison shows that the present invention reverses the temperature of the main cooler from the conventional -25℃ to -5℃~0℃. This is not a conventional design choice for those skilled in the art, but a targeted optimization based on a full understanding of the condensate formation mechanism in high-altitude and low-pressure environments. It has achieved unexpected technical effects such as reducing condensate formation by about 80% while avoiding excessive humidity and frost.

[0077] Comparative Example 2

[0078] To verify that the precise selection of the location of the water collection tank 7 is non-obvious, a comparative example 2 was set up.

[0079] The device structure of Comparative Example 2 is basically the same as that of Example 1, except that the water collection tank 7 is located at the lowest point of the air intake pipe (i.e., the pipe bend and sinking part about 500mm away from the carburetor chamber 11). The other parameters and component structures are exactly the same as those of Example 1.

[0080] Comparative tests were conducted under the same test conditions. The results showed that in Comparative Example 2, the water collection tank 7, located at the bend and sinking point of the pipeline, effectively collected and drained condensate from the downstream of the pipeline. However, inspection through the transparent observation window revealed that 0.5-2 mL of standing water still accumulated at the bottom of the pipeline approximately 20-30 mm upstream of the carburetor 11. This is because the intake pipeline is not an ideal single inclined pipeline, but rather has multiple local low points. Drainage at the geometrically lowest point (the bend) cannot eliminate the water accumulation at the upstream local low points. During the startup test, approximately 5% of the test cycles exhibited an ignition delay of 2-10 seconds, which was confirmed to be caused by a trace "water seal" formed by localized water accumulation upstream of the carburetor.

[0081] In contrast, in Embodiment 1 of the present invention, the water collection tank 7 is precisely set 25mm upstream of the carburetor chamber 11. This position is the sensitive point where the condensate finally gathers and forms a "water seal", which can completely eliminate the water accumulation at this point and achieve a 100% start-up success rate.

[0082] The above comparison shows that the water collection tank 7 is set 20-30mm upstream of the carburetor chamber in this invention. This is a targeted design based on in-depth research on the distribution law of condensate in the intake pipe of the CFR octane number tester and the ignition delay mechanism. It is not something that can be obviously obtained by those skilled in the art under the conventional technical inspiration of "setting a drain outlet at the lowest point of the pipe".

Claims

1. A device for controlling condensate water in the intake system of an octane number measuring machine for high-altitude areas, characterized in that, Includes an intake cooling unit, a temperature fluctuation mitigation unit, and an active drainage unit; The intake cooling unit includes a precooler (3) and a main cooler (8) arranged sequentially along the airflow direction. The precooler (3) is located after the air filter (1). The temperature fluctuation suppression unit includes a heater (4) installed in the air intake pipe, a heat-conducting plate (5) installed on the surface of the heater (4), and a temperature sensor (6). The active drainage unit includes a water collection tank (7), a drain pipe and a drain valve (9); the water collection tank (7) is located at the lowest point of the air intake pipe, at the bottom of the pipe upstream of the carburetor chamber (11), and a drain outlet is opened at the bottom of the water collection tank (7); one end of the drain pipe is connected to the drain outlet and the other end is connected to the external receiving container (10); the drain valve (9) is installed on the drain pipe.

2. The apparatus according to claim 1, characterized in that, The heat-conducting plate (5) is made of a metal material with a specific heat capacity of less than 0.4 J / (g·K), and the surface area of ​​the heat-conducting plate (5) is increased by 20%~30% compared with the original heater heat-conducting plate.

3. The apparatus according to claim 1, characterized in that, The heater (4) is electrically connected to the temperature sensor (6) to form a cascade temperature control loop.

4. The apparatus according to claim 1, characterized in that, The cooling area of ​​the precooler (3) is 1.3 times that of the main cooler (8), and the cooling medium temperature of the precooler (3) is set to -5℃ to 0℃; the cooling medium temperature of the main cooler (8) is set to 0℃ to -2℃.

5. The apparatus according to claim 1, characterized in that, The water collection tank (7) is located at the bottom of the pipe 20-30mm upstream of the carburizing chamber (11).

6. The apparatus according to claim 1, characterized in that, The water collection tank (7) is funnel-shaped, and a filter screen is installed at the bottom drain outlet.

7. A method for controlling condensate water in the intake system of an octane number measuring instrument in high-altitude areas, characterized in that, The condensate control device for the intake system of an octane number analyzer in high-altitude areas according to any one of claims 1-6 includes the following steps: Step 1, Staged cooling: The ambient air is sequentially cooled by passing it through the precooler (3) and the main cooler (8); Step 2, Smoothing temperature fluctuations: Adjust the power of the heater (4) through the temperature control loop, and use the low heat capacity heat conduction plate (5) to quickly respond to temperature changes and control the intake temperature fluctuations within the predetermined range. Step 3, Condensate collection: The condensate generated in the intake pipe is collected by gravity into the water collection tank (7) located at the lowest point of the pipe; Step 4, Active drainage: Before each test cycle begins, open the drain valve (9) to drain the condensate accumulated in the water collection tank (7).

8. The method according to claim 7, characterized in that, In step one, the precooler (3) initially cools the air to -5°C to 0°C, and the main cooler (8) precisely cools the air to the target temperature of 5±1°C.

9. The method according to claim 7, characterized in that, In step two, the temperature control loop is a cascade temperature control loop, with the intake air temperature as the main control parameter and the heater (4) power as the secondary control parameter. When the intake air temperature deviates from the set value, the heater (4) power is adjusted first to compensate.

10. The method according to claim 7, characterized in that, In step four, when a solenoid valve is used as a drain valve (9), the controller automatically opens the solenoid valve for 2-5 seconds before each test cycle begins to drain the water.

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