A special low emission high efficiency fuel for parallel hybrid vehicles

Abstract

The present application belongs to the field of new fuel, and specifically provides a special low-emission high-efficiency fuel for parallel hybrid electric vehicles, which mainly comprises alkylated gasoline, oxygen-containing fuel, hydrogenated gasoline, C7 aromatic hydrocarbon, C8 aromatic hydrocarbon, high olefin C5 and raffinate oil. Compared with traditional vehicle gasoline, the special fuel has low C9+ aromatic hydrocarbon content, higher alcohol addition and higher paraffin content, which ensures better fuel economy and lower emission characteristics of the parallel hybrid engine under the frequent start-stop working condition. The low C9+ aromatic hydrocarbon content and alcohol fuel can reduce PN emission; at the same time, the alcohol fuel and high paraffin content can increase the flame propagation speed and combustion stability, so that the PN emission is reduced and the combustion efficiency is improved during the start-stop process, which can realize more than 50% reduction of PN emission and 5%-10% reduction of fuel consumption.

Description

Technical Field

[0001] This invention belongs to the field of new fuels, specifically providing a dedicated low-emission, high-efficiency fuel for parallel hybrid electric vehicles. Background Technology

[0002] The market share of hybrid electric vehicles (HEVs) is increasing, offering better fuel economy and emissions than traditional internal combustion engine vehicles. However, many studies indicate that in hybrid operation, the choice of fuel is generally for commercially available 92 or 95 octane gasoline. Because hybrid engines are typically designed with high compression ratios and Atkinson cycles, and the vehicle operates with frequent start-stop cycles, this leads to increased particulate matter (PN) emissions and, under certain conditions, poorer combustion and increased fuel consumption. Current research primarily focuses on optimizing control strategies, with engine optimization as a secondary measure. However, there has been very little focus on upgrading and optimizing the fuel type for HEVs to reduce PN emissions and fuel consumption.

[0003] Furthermore, existing hybrid vehicles differ from traditional vehicles in the following ways:

[0004] 1. The engines in hybrid vehicles differ significantly from traditional engines: they utilize technologies such as high compression ratio and Atkinson cycle.

[0005] 2. Different overall structural design: There are two power sources, the battery and the engine.

[0006] 3. Different control strategies: For example, automatic start-stop. In traditional vehicles, the automatic start-stop function is mainly caused by vehicle speed stagnation, while in hybrid vehicles, automatic start-stop is a coordination between the battery and the engine, and the engine starts and stops much more frequently than in traditional vehicles.

[0007] 4. Parallel hybrid vehicles have engines operating in a region closer to that of conventional vehicles, resulting in a higher tendency for knocking due to their high compression ratio compared to other hybrid configurations. Furthermore, some studies have shown that hybrid vehicles have higher particulate emissions (PN) compared to conventional vehicles.

[0008] Therefore, whether a dedicated fuel can be developed based on the operating conditions and emissions of hybrid vehicle engines has become one of the urgent problems to be solved by those skilled in the art. Summary of the Invention

[0009] This invention addresses the shortcomings of existing technologies by providing a novel fuel technology, specifically a dedicated low-emission, high-efficiency fuel for parallel hybrid electric vehicles. Its main components include alkylated gasoline, oxygenated fuel, hydrogenated gasoline, C7 aromatics, C8 aromatics, high-olefin C5 fuel, and raffinate. Compared to traditional automotive gasoline, this dedicated fuel features a lower C9+ aromatic content, higher alcohol content, and higher alkanes content, ensuring superior fuel economy and lower emissions under frequent start-stop conditions in parallel hybrid engines. The low C9+ aromatic content and alcohol content reduce particulate matter (PN) emissions; simultaneously, the alcohol content and high alkanes content increase flame propagation speed and combustion stability, further reducing PN emissions and improving combustion efficiency during start-stop processes. This results in a more than 50% reduction in PN emissions and a 5%-10% reduction in fuel consumption for parallel hybrid electric vehicles.

[0010] The inventive concept of this invention is:

[0011] Based on data on the operating conditions and emissions degradation of hybrid vehicle engines, the design optimizes the PN emissions and fuel consumption rate of parallel hybrid vehicles by optimizing the component ratio and adding new components to a dedicated fuel.

[0012] The parallel hybrid electric vehicle targeted by this invention is equipped with a turbocharged gasoline engine, and the overall power system is of a parallel configuration, with a dual power source system of engine and battery motor, belonging to the mass-produced and commercially available vehicle type.

[0013] The inventors considered issues such as knocking caused by the high compression ratio of hybrid-specific engines and emissions pollution caused by frequent automatic start-stop in hybrid vehicle control strategies during the process of determining the component blending. The specific considerations are as follows:

[0014] High compression ratios lead to excessively high in-cylinder and exhaust temperatures. The afterburning of heavy aromatics is one of the causes of this excessive temperature. This application addresses this by reducing C9+ aromatics and adding isopentenol, which effectively lowers in-cylinder and exhaust temperatures and improves combustion efficiency. Compared to traditional vehicles, the frequent start-stop cycles of hybrid vehicles are a major contributor to PN emissions. The inventors reduce PN emissions through two methods: adding oxygenated fuels and increasing the proportion of alkanes while reducing C9+ aromatics.

[0015] Oxygenated fuels include MTBE and isopentenol. MTBE is a commonly used oxygenated component in fuel blending, characterized by its high octane rating, oxygen-containing functional groups, high density, and low boiling point, which helps improve the in-cylinder mixture uniformity and combustion state. Isopentenol is a high-boiling-point fuel containing hydroxyl groups and double bonds, with a boiling point around 115°C, located in the middle to late-boiling range (T50-T90). Due to its oxygen-containing functional groups and highly reactive double bonds, it promotes the combustion of substances in the middle to late-boiling range after mixing with air in the cylinder. Aromatics in the middle to late-boiling range are one of the main factors affecting particulate matter (PN) emissions. Therefore, the addition of MTBE and isopentenol can further optimize in-cylinder combustion, reduce fuel consumption, and lower PN emissions.

[0016] Alcohol fuels and high alkane content can increase flame propagation speed and combustion stability, resulting in reduced PN emissions and improved combustion efficiency during frequent start-stop processes. The reduction of C9+ aromatics helps the combustion state in the cylinder, suppresses the formation of particulate precursors, and thus reduces PN emissions.

[0017] Based on the above inventive concepts, the specific technical solution adopted by this invention is as follows:

[0018] A dedicated low-emission, high-efficiency fuel for parallel hybrid electric vehicles comprises, by volume fraction, 7%-10% oxygenated fuel, 8%-12% C7 aromatics, 10%-15% C8 aromatics, 6%-9% high-olefin C5, 2%-5% raffinate, 19%-22% alkylated gasoline, and hydrogenated gasoline as the balance to make up 100%.

[0019] Furthermore, the preferred balance of hydrogenated gasoline is 44-46%.

[0020] Among the above components, hydrogenated gasoline is a commercially available conventional product, and its product price and process are more advantageous in the market. In the overall scheme, C9+ aromatics mainly come from this component, but the C9+ aromatics in the selected hydrogenated gasoline can all be less than 10% (V / V); C7 aromatics are selected from toluene, C8 aromatics are selected from xylene, high olefin C5 and raffinate are conventional products in this field, and the inventor will not elaborate further.

[0021] Among the above components, alkylated gasoline and oxygenated fuels are two key components. The straight-chain alkanes in alkylated gasoline help to accelerate the flame propagation speed, thereby improving the combustion efficiency during frequent start-stop cycles. The high octane number also helps to improve the overall anti-knock properties of the fuel, making it suitable for the high compression ratio characteristics of hybrid engines.

[0022] The oxygenated fuel consists of isopentenol and methyl tert-butyl ether in a volume ratio of 1:(2-3). The hydroxyl groups and carbon-carbon double bonds in this mixture help improve combustion completeness during frequent starts, reduce the probability of particulate precursor formation in the engine, and thus reduce particulate emissions. The high octane rating of the mixture also helps reduce the knocking region of the hybrid engine at high compression ratios, improving its operating range. Further preferred specifications include a Research Octane Number (RI) of not less than 119, a Motor Octane Number (MAN) of not less than 107, and a density of not less than 800 kg / m³. 3 The distillation range is 55℃-140℃.

[0023] In addition, the inventors also provided the following method for preparing the aforementioned special fuel:

[0024] First, hydrogenated gasoline is injected into the blending tank, followed by C7 aromatics, C8 aromatics, high-olefin C5, oxygenated fuel, and raffinate oil in sequence. Finally, alkylated gasoline is added. After all the above raw materials are added in proportion, nitrogen gas is introduced into the tank for protection, and then the pump is started to circulate and mix.

[0025] The fuel obtained by the above method has the following properties after testing:

[0026] The research octane number is 95-97, and the density (20℃) is 745-755 kg / m³. 3 ), vapor pressure not less than 47 kPa, C9+ aromatic content (volume fraction) of 5-7%, distillation range of 30℃-195℃, and oxygen content not higher than 10% (V / V).

[0027] In conventional preparation methods, the space above the materials stored in the mixing tank is filled with air. In order to minimize the contact between various fuel components and air and slow down the oxidation process, the inventors specifically chose to fill the tank with nitrogen for protection in the above preparation method.

[0028] Compared with the prior art, the advantages of the present invention are as follows:

[0029] The fuel provided by this invention was tested in a 1.5T parallel hybrid vehicle. The results showed that compared with the currently available 92 and 95 octane fuels, it can reduce PN emissions by more than 50% and reduce fuel consumption by 5%-10%. Detailed Implementation

[0030] The following detailed description, in conjunction with specific embodiments, further illustrates the above-mentioned content of the present invention. However, it should not be construed as limiting the scope of the subject matter of the present invention to the following examples. All technologies implemented based on the above-mentioned content of the present invention fall within the scope of the present invention. Unless otherwise specified, the raw materials used in the following embodiments are all commercially available products.

[0031] The hydrogenated gasoline in the following examples is a commercially available conventional product, and the C9+ aromatics in the selected hydrogenated gasoline are all below 10% (V / V); the C7 aromatics are selected from toluene, the C8 aromatics are selected from xylene, and the high olefin C5 and raffinate are conventional products in the art.

[0032] More specifically: hydrogenated gasoline was purchased from Shandong Jingbo Petrochemical Co., Ltd., alkylated gasoline from Binzhou Dayou New Energy Development Co., Ltd., methyl tert-butyl ether from Shandong Jingbo Petrochemical Co., Ltd., isopentenol from Shanghai Yi'en Chemical Technology Co., Ltd., toluene and xylene from Shandong Jingbo Petrochemical Co., Ltd., high-olefin C5 from Shenhua Xinjiang Energy Co., Ltd., and raffinate from Shandong Jingbo Petrochemical Co., Ltd.

[0033] Example 1

[0034] A dedicated low-emission, high-efficiency fuel for parallel hybrid electric vehicles, the main components of which, by volume percentage, are:

[0035] Alkylated gasoline 20%, oxygenated fuels 6%, hydrogenated gasoline 45%, C7 aromatics 10%, C8 aromatics 10%, high-olefins C5 7%, and raffinate 2%.

[0036] The oxygen-containing fuel mentioned therein is a mixture of isopentenol and methyl tert-butyl ether in a volume ratio of 1:3.

[0037] Its preparation method is as follows:

[0038] First, hydrogenated gasoline is injected into the blending tank, followed by C7 aromatics, C8 aromatics, high-olefin C5, oxygenated fuel, and raffinate oil in sequence. Finally, alkylated gasoline is added. After all the above raw materials are added in proportion, nitrogen gas is introduced into the tank for protection, and then the pump is started to circulate and mix.

[0039] The final special fuel has the following characteristics: Research Octane Number 96.5; Density (20℃) 749.6 kg / cm³ 3 Vapor pressure 48.6 kPa; Aromatic content (volume fraction) 31.9%; C9+ aromatic content (volume fraction) 5.3%; Final boiling point 191.6℃.

[0040] Example 2

[0041] A dedicated low-emission, high-efficiency fuel for parallel hybrid electric vehicles, the main components of which, by volume percentage, are:

[0042] Alkylated gasoline 18%, oxygenated fuels 8%, hydrogenated gasoline 45%, C7 aromatics 10%, C8 aromatics 10%, high-olefins C5 7%, and raffinate 2%.

[0043] The oxygen-containing fuel mentioned therein is a mixture of isopentenol and methyl tert-butyl ether in a volume ratio of 1:2.

[0044] The preparation method is as described in Example 1.

[0045] The final special fuel has the following characteristics: Research Octane Number (ROC) of 96.8; density (at 20°C)

[0046] 750.1 kg / cm 3 Vapor pressure 48.5 kPa; Aromatic content (volume fraction) 32.8%; C9+ aromatic content (volume fraction) 5.1%; Final boiling point 191℃.

[0047] Example 3

[0048] A dedicated low-emission, high-efficiency fuel for parallel hybrid electric vehicles, the main components of which, by volume percentage, are:

[0049] Alkylated gasoline 16%, oxygenated fuels 10%, hydrogenated gasoline 45%, C7 aromatics 10%, C8 aromatics 10%, high-olefins C5 7%, and raffinate 2%.

[0050] The oxygen-containing fuel mentioned therein is a mixture of isopentenol and methyl tert-butyl ether in a volume ratio of 1:3.

[0051] The preparation method is as described in Example 1.

[0052] The final special fuel has the following characteristics: Research Octane Number 97.1; Density (20℃)

[0053] 751.2 kg / cm 3 Vapor pressure 48.6 kPa; Aromatic content (volume fraction) 33.8%; C9+ aromatic content (volume fraction) 5.5%; Final boiling point 191.7℃.

[0054] Experimental Example

[0055] Using commercially available 95-octane gasoline as Comparative Example 1, the actual test results of the samples from the above-mentioned embodiments and Comparative Example 1 are shown in the table below:

[0056]

[0057] Based on the actual test results, Comparative Example 1 mainly shows that the C9+ aromatic hydrocarbon content is more than 2.8 times that of Examples 1-3, while the other indicators are similar.

[0058] Whole vehicle drum test:

[0059] 1. Testing the entire vehicle's rotary drum platform: Single rotary drum testing platform;

[0060] 2. Test vehicle: Parallel hybrid electric vehicle (1.5T engine), without a particulate filter (GPF);

[0061] 3. Ambient temperature: 25℃±3℃;

[0062] 4. Test plan: Commercially available 95-octane gasoline was used as the reference fuel, and the fuel consumption and PN emissions were compared with those of Examples 1-3.

[0063] During the test, the ambient temperature was kept constant, and the vehicle fuel consumption rate and PN emissions under the WLTC cycle were tested without adjusting the hybrid vehicle engine parameters and vehicle control parameters.

[0064] Whole vehicle drum test results

[0065] additive Fuel consumption rate (L / 100km) PN emissions (# / km) Commercially available No. 95 5.366 <![CDATA[1.026*10 12 <!-- 4 -->]]> Example 1 4.737 <![CDATA[2.513*10 11 ]]> Example 2 4.934 <![CDATA[4.390*10 11 ]]> Example 3 4.774 <![CDATA[2.577*10 11 ]]>

[0066] Based on the WLTC cycle, a whole-vehicle drum test was conducted on the aforementioned parallel hybrid electric vehicle. The test results are shown in the table above. Compared with commercially available 95-octane gasoline, the fuel consumption rate in Examples 1-3 decreased by 11.72%, 8.05%, and 11.03%, respectively; PN emissions compared with commercially available 95-octane gasoline in Examples 1-3 decreased by 75.51%, 57.22%, and 74.88%, respectively. The comparison shows that, compared with commercially available 95-octane gasoline, without changing the vehicle engine parameters and vehicle control logic, the technical solution of this application can achieve a reduction of more than 50% in PN emissions and a reduction of 5%-10% in fuel consumption.

[0067] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dedicated low-emission, high-efficiency fuel for parallel hybrid electric vehicles, characterized in that: Its components, by volume fraction, include 7%-10% oxygenated fuel, 8%-12% toluene, 10%-15% xylene, 6%-9% high-olefin C5, 2%-5% raffinate, 19%-22% alkylated gasoline, and hydrogenated gasoline as the balance to make up 100%. The oxygenated fuel is a combination of isopentenol and methyl tert-butyl ether in a volume ratio of 1:2-3. The oxygenated fuel has a Research Octane Number (RON) of not less than 119, a Motor Octane Number (MAN) of not less than 107, and a density of not less than 800 kg / m³. 3 The distillation range is 55℃-140℃; The volume percentage of C9+ aromatics in hydrogenated gasoline is less than 10%.

2. The dedicated low-emission, high-efficiency fuel for parallel hybrid electric vehicles according to claim 1, characterized in that: Hydrogenated gasoline has a volume fraction of 44-46%.

3. The method for preparing the dedicated low-emission, high-efficiency fuel for parallel hybrid electric vehicles as described in claim 1, characterized in that, The specific steps are as follows: First, inject hydrogenated gasoline into the blending tank, then add toluene, xylene, high-olefin C5, oxygenated fuel, and raffinate in sequence, and finally add alkylated gasoline. After all the above raw materials are added in proportion, fill the tank with nitrogen for protection and then start the pump to circulate and mix.

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