CN102021049A - E2 ethanol-diesel blend fuel - Google Patents

Abstract

The invention discloses an E2 ethanol-diesel blend fuel, comprising the following raw materials in parts by volume: 2 parts of absolute ethanol and 98 parts of diesel, wherein the diesel can be one or more of finished diesel, straight-run diesel, and secondary processing diesel. Compared with the prior art, the E2 ethanol-diesel blend fuel has the beneficial effects that the requirement for quality basic diesel is low, thus being suitable for all diesels; compared with the basic diesel, the dynamic property of an engine is not influenced basically; the evaporability of the blend fuel is reduced, the safety of the transportation and the usage is improved; and miscibility and water solubility of diesel and ethanol are improved and optimized.

Description

E2 Ethanol Diesel Blend Fuel

technical field

The invention relates to a liquid carbon-containing fuel, in particular, a kind of ethanol-diesel mixed fuel. the

Background technique

Domestic research papers on ethanol diesel began to appear in 2002, and their work mainly focused on ethanol diesel co-solvent and emission characteristics of ethanol diesel. The research on ethanol diesel was earlier in foreign countries. Brazil started the ProAlcoo project in 1975, the United States started fuel ethanol work in 1978, and then Canada and Europe also started fuel ethanol work. Brazil's fuel ethanol mainly comes from sugarcane, and its products include hydrous ethanol and anhydrous ethanol. The fuel ethanol in the United States mainly comes from corn and a small amount of wheat and barley. The fuel ethanol in Canada mainly comes from corn and a small amount of wheat. For the application of fuel ethanol, except for the large-scale use of hydrous ethanol directly as automobile fuel in Brazil, the general use is to use fuel ethanol as a component or oxygen-containing additive of fuel (including gasoline and diesel) and blend it with fuel. The basic physical properties of absolute ethanol are shown in Table 1. the

Table 1 Basic physical properties of absolute ethanol melting point boiling point Relative density saturated vapor pressure Heat of combustion Flash point Compression ignition temperature Explosion limit (V/V) Solubility -114.1°C 78.3°C 0.79 5.33kPa /19℃ 1365.5 kJ/mol 12°C 363°C 3.3%～19.0% Miscible with water, miscible in most organic solvents such as ether, chloroform, glycerin, etc.

From the physical properties of ethanol and the existing work basis, it can be seen that as the amount of ethanol added to diesel increases, the density of ethanol diesel decreases, the temperature of each distillation decreases, the viscosity decreases, the calorific value decreases, and the cetane number decreases , Lower flash point, lower wear resistance. Therefore, in order to make ethanol diesel into large-scale use, three problems must be solved: cetane number reduction, flash point reduction, and wear resistance problems. In addition, due to the different compatibility between ethanol and diesel, it is necessary to study the stability of ethanol and diesel, especially the problem of phase separation at low temperature; usually, the addition of alcohol will increase the corrosion of metal materials and the swelling of rubber materials. The selection of component materials mainly considers its corrosiveness in the presence of diesel oil. Therefore, it is necessary to study the corrosion of metals and the swelling of rubber after the addition of ethanol.

However, ethanol-diesel blended fuel contains oxygen in the ethanol molecule compared to base diesel. The presence of oxygen will have the following two opposite effects on the work of the engine: On the one hand, the presence of oxygen can lead to a decrease in the content of combustible components (C, H) in the same weight of ethanol diesel, so that the engine torque and The power decreases and the fuel consumption rate increases; on the other hand, the presence of oxygen can lead to more complete combustion of fuel in the engine, thereby improving engine combustion, increasing engine torque and power, and reducing fuel consumption rate. the

Contents of the invention

The technical problem to be solved by the present invention is to find out the optimum volume percentage concentration of ethanol in the ethanol-diesel mixed fuel, under this optimum percentage concentration, the fuel consumption rate of ethanol-diesel is equivalent to that of base oil. the

In order to achieve the above object, the technical scheme of the present invention is as follows: a kind of E2 ethanol diesel blended fuel, comprises the raw material mixing of following parts by volume and makes:

2 parts ethanol

Diesel 98 parts

Ethylene glycol ether or ethylene glycol methyl ether 0.1~0.3 parts

The above-mentioned ethanol is absolute ethanol or industrial alcohol; the above-mentioned diesel oil is one or a mixture of finished diesel oil, straight-run diesel oil, and secondary processed diesel oil.

The present invention finds out the optimum volume percentage concentration of ethanol in ethanol-diesel blended fuel through a large number of experimental studies, under this optimum percentage, the fuel consumption rate of ethanol-diesel is equivalent to base oil, to improve the engine performance of ethanol-diesel blended fuel power. Add 0.1~0.3 parts of ethylene glycol ether or ethylene glycol methyl ether as a waterproofing agent. the

Its role:

If the base component is denatured alcohol, as a necessary solvent;

If the base component is absolute ethanol, it is used as a necessary water-retaining agent (to allow proper water absorption during storage) .

In order to reduce the evaporability of the mixed fuel, 0.8-1.2 parts by volume of butanol or octanol is added to the E2 ethanol-diesel mixed fuel; 0.8-1.2 kg of KCl is added to the 100ml E2 ethanol-diesel mixed fuel. the

In order to improve the miscibility of diesel oil and ethanol, a co-solvent consisting of 1-1.2 parts by volume of n-butanol and 0.3-0.4 parts by volume of isoamyl alcohol is added to the E2 ethanol-diesel blended fuel. the

In order to improve the water solubility of the mixed fuel, 4-6 parts by volume of n-butanol, isobutanol, isooctyl alcohol or isoamyl alcohol are added to the E2 ethanol-diesel mixed fuel. the

The following are the performance parameter tests of ethanol diesel

1 Mixing performance test of ethanol diesel

1.1 Test raw materials

Absolute ethanol: commercially available, analytically pure.

Chang 2 Diesel Oil: It is obtained from the 5 million tons atmospheric and vacuum distillation unit 2 of Lanzhou Oil Refinery. the

Changsan Diesel Oil: It is obtained from the 5 million tons of atmospheric and vacuum distillation unit 3 of Lanzhou Oil Refinery. the

Cracked diesel oil: from the 1.4 million tons catalytic cracking unit of Lanzhou Oil Refinery. the

Hydrogenated diesel oil: from the 1.2 million tons hydrorefining unit of Lanzhou Oil Refinery. the

0# commodity diesel: commercially available. the

1.2 The maximum amount of ethanol dissolved by different base diesel oil

At room temperature, add absolute ethanol dropwise to different base diesel oils and shake until the system is opaque. The measured maximum dissolution of absolute ethanol by different base diesel oils is shown in Table 8.2.

Table 1 The maximum solubility of different base diesel oils to absolute ethanol (volume percentage) base diesel Diesel oil Chang San Diesel Hydrogenated Diesel cracked diesel 0# commodity diesel Maximum miscibility 7.75% 3.85% 6% 100% 100%

Note: 100% miscibility means that the base diesel oil can be miscible with absolute ethanol in any proportion.

the

It can be seen from Table 1 that the maximum solubility of different base oils to ethanol is different, from very small (3.85%) to completely miscible.

1.3 Miscibility of ethanol-diesel system

Different diesel oils were used as base oils, mixed with absolute ethanol at volume percentages of 2% and 4%, respectively, and their miscibility was observed. The results are shown in Table 2.

Table 2 Miscibility of different base diesel oils with absolute ethanol E2 E4 Often two Transparent without layering Transparent without layering Chang San Transparent without layering layered catalytic cracking Transparent without layering Transparent without layering Hydrofining Transparent without layering Transparent without layering 0# commodity diesel Transparent without layering Transparent without layering

Note: Ex means that the volume percentage of absolute ethanol is x (the same below).

the

It can be seen from Table 1 and Table 2 that under the maximum solubility of ethanol, different base diesel oils and absolute ethanol can be miscible at various ratios.

1.4 Long-term stability of different ethanol diesels

Stand the ethanol diesel in Table 1 at room temperature for 2 months to observe its stability. All ethanol-diesel is sealed and static to eliminate the influence of moisture. The results are shown in Table 3.

Table 3 Long-term stability of ethanol diesel with different base oils E2 E4 Diesel oil Transparent without layering Transparent without layering Chang San Diesel Transparent without layering layered cracked diesel Transparent without layering Transparent without layering Hydrogenated Diesel Transparent without layering Transparent without layering 0# commodity diesel Transparent without layering Transparent without layering

It can be seen from Table 3 that under the maximum solubility of anhydrous ethanol, ethanol mixtures of different base diesel oils in various proportions can be miscible under long-term standing conditions.

the

1.5 Effect of moisture on the miscibility of ethanol-diesel system

Take 20ml of prepared ethanol diesel with different proportions, add water drop by drop, and oscillate until the system is opaque. The measured results of the maximum water capacity of ethanol diesel are shown in Table 4.

Table 4 Maximum water capacity (drops) of different ethanol diesels E2 E4 Diesel oil 8 8 Chang San Diesel 1 - cracked diesel 1 1 Hydrogenated Diesel 2 2 0# commodity diesel 1 1

Note: After standing for 2 months, different base oils and different proportions of ethanol diesel will maintain the initial state.

the

It can be seen from the results in Table 4 that:

(1) Moisture can significantly affect the stability of ethanol diesel;

(2) The maximum water capacity of ethanol diesel oil is related to the base oil. In this experiment, the base oil with the best water capacity is ordinary diesel oil. The maximum water capacity in conversion (calculated as 23 drops per ml of water) can reach 1.7%. The maximum water capacity of diesel oil is less than 0.4%, and the maximum water capacity of regular three diesel oil, cracked diesel oil and 0# commercial diesel oil is less than 0.2%;

(3) Under the experimental conditions, the maximum water capacity of ethanol diesel has nothing to do with the ethanol content;

(4) Moisture does not affect the long-term stability of ethanol diesel.

1.6 The effect of co-solvent on the miscibility of ethanol and diesel

Using the single or mixed agent of higher alcohol as co-solvent, the effects of co-solvent on ethanol-diesel and water-ethanol-diesel systems were investigated respectively.

(1) Effect of alcohol co-solvent on ethanol-diesel system

From the data in Table 1, it can be seen that the maximum ethanol solubility of conventional di-diesel, conventional 3-diesel and hydrogenated diesel is relatively small. In this paper, the mutual solubility of ethanol and diesel is improved by adding higher alcohols.

The test found that: when added in a single dose, n-butanol, isobutanol, isooctyl alcohol, and isoamyl alcohol can significantly improve the compatibility of ethanol with di-diesel, di-diesel, and hydrogenated diesel. However, the amount of co-solvent added is relatively large, and the amount of ethanol solubility can be significantly increased when it is above 5%. the

If various alcohols are used in combination, for di-diesel, the formula of 1.12% n-butanol + 0.37% isoamyl alcohol has a better solubilizing effect (making ethanol and diesel completely miscible without delamination, and stable for long-term sealed storage good sex). In addition, various compound formulas have unsatisfactory effect on the solubilization of conventional three diesel oil and hydrogenated diesel oil. the

(2) Effect of alcohol ether co-solvents on the water capacity of ethanol diesel

Using industrial alcohol (water content 5% v) as the basic component of ethanol diesel and ethylene glycol ether or ethylene glycol methyl ether as co-solvent, the minimum amount of co-solvent that can make the ethanol-diesel system completely miscible is investigated. The results are shown in Table 5 .

The amount of co-solvent when table 5 technical alcohol is the base component Ethanol content (%v/v) Ethylene glycol ether dosage (drops) Amount of ethylene glycol methyl ether (drops) Phenomenon 2 8 7 Clear and transparent without layering 4 15 15 Clear and transparent without layering

From the experimental data in this section, it can be known that:

Although the miscibility of ethanol and diesel oil is better, and there is a certain degree of water tolerance. However, higher alcohol co-solvents (whether used as a single agent or in combination) are not effective in improving the solubility and water-holding properties of ethanol diesel. In order to achieve a more ideal effect of solubilization and water storage, the amount of co-solvent is usually very large, which will lead to a substantial increase in cost in actual use.

There is no national standard for ethanol diesel for vehicles, so we cannot judge the moisture content of ethanol diesel for vehicles that may be used in the future. However, considering that the external environment (water absorption) of ethanol gasoline for vehicles and ethanol diesel for vehicles is not much different during storage and use, refer to the relevant content of GB 18351-2004 "Ethanol Gasoline for Vehicles", and ethanol fuels allow The water content should be less than 0.20% (m/m). the

From the influence of water on ethanol diesel for vehicles, and the effect of alcohol co-solvents on the miscibility and stability of ethanol diesel: due to the strong water absorption of ethanol, ethanol diesel for vehicles will inevitably be absorbed from the surrounding environment (oil space in tanks, piping, etc.) to absorb water. According to the research results of this paper, once the ethanol diesel for vehicles absorbs water, it will affect the miscibility and stability of ethanol diesel for vehicles; moreover, the problem of miscibility and stability decline is solved by adding alcohol co-solvents conventionally. It will lead to a substantial increase in cost, thereby limiting the large-scale application of ethanol diesel for vehicles. the

At this time, ethylene glycol ether or ethylene glycol methyl ether can be used as a waterproofing agent due to its excellent water tolerance. Water repellent has two functions:

(1) When using, prevent delamination caused by water absorption;

(2) Industrial alcohol can be directly used as the basic composition of ethanol diesel, thereby greatly reducing the production cost of ethanol diesel.

2 Evaporation test of ethanol diesel

2.1 Distillation range

According to GB/T6536-97, the distillation range of ethanol diesel prepared with 0# diesel oil as the base oil under the atmospheric pressure of 97.8kPa is respectively measured, and the results are shown in Figure 1:

It can be clearly seen from Figure 1 that after adding ethanol, compared with 0# base diesel, ethanol diesel

(1) The initial boiling point is significantly lowered to around the boiling point of ethanol (78.3°C);

(2) The distillation temperature before 20% volume is significantly lower;

(3) After 30% volume, the decrease of distillation temperature is related to the amount of ethanol added. The more ethanol is added, the greater the drop of distillation temperature.

According to the data in the above figure, ethanol mainly affects the initial boiling point and 10% distillation temperature of ethanol diesel. In the follow-up test, only the initial boiling point and 10% distillation temperature of ethanol diesel prepared with various intermediate diesel products as base oil were measured, and the results are shown in Table 6 and Table 7. the

Table 6 Initial boiling points of different base diesel ethanol diesels (°C) E0 E2 E4 Diesel oil 171 75 74 Chang San Diesel 190 76 74 Hydrogenated Diesel 182 74 75 cracked diesel 164 77 74

Table 7 10% distillation temperature of different base diesel ethanol diesel (°C) E0 E2 E4 Diesel oil 226 214 182 Chang San Diesel 234 221 190 Hydrogenated Diesel 230 217 187 cracked diesel 214 200 175

From Table 6 to Table 7, it can be seen that after adding ethanol, ethanol diesel

(1) The initial boiling point is lowered. Probably due to the formation of azeotrope, the initial boiling point of ethanol diesel will be lower than that of absolute ethanol.

(2) The 10% distillate temperature decreased, and with the increase of ethanol addition, the 10% distillate temperature drop of ethanol diesel increased. the

It is worth noting that when the addition amount is 10%, the 10% distillation temperature of ethanol diesel is near the boiling point of ethanol, indicating that in the process of distillation, ethanol is distilled earlier than diesel oil alone. In use, this characteristic of ethanol diesel may affect the normal operation of the engine. the reason is:

During engine start-up and warm-up, due to the low engine temperature, only those light components are likely to vaporize at a lower temperature and form a combustible mixture with air. The 10% distillation temperature of an oil product is an index reflecting the light component content of the oil product. Generally, the lower the 10% distillation temperature is, the easier it is for the engine to start and warm up during actual use. But for ethanol diesel, since ethanol evaporates earlier than diesel alone, it may cause a large amount of ethanol in the light components vaporized at low temperature. And because the compression ignition performance of ethanol itself is worse than that of diesel oil, as a result, there may be adverse consequences such as difficulty in starting and prolonged warm-up time during use.

2.2 Reid method saturated vapor pressure

According to GB/T8017-87, the Reid method saturated vapor pressure of ethanol diesel with 0# diesel as base oil was measured, and the test results are shown in Figure 2.

It can be seen from Figure 2 that:

(1) After adding ethanol, the Reid method saturated vapor pressure of ethanol diesel increases;

(2) The inflection point of the Reid method saturated vapor pressure growth curve appears at the moment when the ethanol content is 8%: when the content is 10%, the increase of the Reid method saturated vapor pressure of ethanol diesel is accelerated.

The saturated vapor pressure of Reid's method mainly reflects the evaporation performance of light components in oil. After adding low-boiling ethanol to diesel, the saturated vapor pressure of ethanol diesel increases rapidly. It is worth noting that, according to the research results of ethanol gasoline, when the addition of ethanol is 10%, the saturated vapor pressure of ethanol gasoline will increase by about 5kPa ^[81] . According to the results of Reid's method saturated vapor pressure in this experiment, the effect of ethanol on the evaporability of diesel oil is compared with the effect on the evaporability of gasoline, and the results are similar.

the

From the results of the distillation range and saturated vapor pressure of ethanol diesel, it can be seen that after adding ethanol, ethanol diesel becomes easy to evaporate. From the point of view of use, there are three main adverse effects of excessive evaporation of fuel: increasing the evaporation loss in storage, causing air resistance when driving, and increasing the fire hazard of fuel. From the perspective of diesel oil, since the evaporation of diesel oil itself is far worse than that of gasoline, and the absolute value of the influence of ethanol on the saturated vapor pressure and distillation range of diesel oil is not large, after adding ethanol, the evaporation loss of diesel oil and the driving gas The impact of resistance can be ignored. Then, the addition of ethanol will mainly affect the fire hazard of diesel.

2.3 Effect of evaporation improver on saturated vapor pressure of ethanol diesel

The Reid's method saturation vapor pressure of ethanol diesel was investigated after adding two types of evaporation improvers. The results are shown in Table 8. Among them, the molecular weight of improver A is lower than that of B.

Table 8 Reid method saturated vapor pressure/kPa of ethanol diesel after adding evaporation improver 0# diesel E2 E4 No additives 6.865 7.845 8.336 Ethanol diesel + co-solvent A - 6.865 7.356 Ethanol diesel + co-solvent B - 7.356 7.845

It can be seen from Table 8 that the evaporation improver can reduce the saturated vapor pressure of ethanol diesel; for the low proportion of ethanol diesel (E2), adding the evaporation improver can reduce the saturated vapor pressure of ethanol diesel to the level of 0# diesel; the two kinds of evaporation improver Compared with the effect of low molecular weight modifier, the effect of low molecular weight modifier is better than that of high molecular weight modifier.

The evaporation improver is an organic compound with large molecular weight and low volatility. After being added to ethanol diesel, it forms an azeotrope with a higher boiling point with ethanol, thereby reducing the volatility of ethanol and achieving the purpose of reducing the saturated vapor pressure of ethanol diesel. The volatility and molecular weight of the evaporation improver will affect its use effect: if the molecular weight is too small, the volatility will be high, and an azeotrope with a lower boiling point may be formed, which will further increase the evaporation of the mixed system ; And when the molecular weight is too large, the stability of the azeotrope is reduced, thereby making the effect worse. Therefore, according to the results of this experiment, the molecular weight of the evaporation improver should be appropriate. the

3 Low temperature performance test of ethanol diesel

3.1 Freezing point

According to GB/T510-91, the freezing point of different base diesel and its ethanol diesel was determined, and the results are shown in Table 9.

Table 9 Freezing point of ethanol diesel oil/℃ base oil E0 E2 E4 0# diesel -10 -12 -12 Diesel oil -9.0 -9.0 -9.1 Chang San Diesel 18.4 18.1 18.0 Hydrogenated Diesel 10.2 10.1 9.9 cracked diesel 2.1 2.0 1.6

It can be seen from Table 9 that ethanol has a certain influence on the freezing point of diesel oil, the greater the ethanol content, the lower the freezing point.

The freezing point is an important indicator of diesel, which is directly related to the lowest temperature of diesel used by vehicles. It can be seen from Table 9 that the freezing point of ethanol diesel is slightly lowered after adding ethanol. The lowering of the freezing point of ethanol diesel is beneficial to the use of ethanol diesel at a lower ambient temperature. However, considering that the addition of ethanol does not have a significant effect on the lowering of the freezing point, it can be considered that the addition of ethanol will at least not cause the low-temperature performance of ethanol diesel to deteriorate, that is, ethanol diesel can be used at low temperatures. use below. the

3.2 Cold filter point

The freezing point of different base diesel and its ethanol diesel was determined by SH/T 0248-92, and the results are shown in Table 10.

Table 10 Cold filter point of ethanol diesel oil/℃ base oil E0 E2 E4 Diesel oil -9.9 -9.8 -10.5 Chang San Diesel >20 17.5 14.5 Hydrogenated Diesel 11.5 11.2 11.1 cracked diesel 5.0 1.5 1.3

It can be seen from Table 10 and Table 9 that:

After adding ethanol, the cold filter point of ethanol-diesel decreased; and with the increase of the added amount, the degree of decrease of the cold filter point increased.

It is worth noting that: relative to the freezing point, ethanol has a more obvious effect on reducing the cold filter point. From the perspective of use, compared with the freezing point, the cold filter point is more representative of the minimum operating temperature of diesel oil. Therefore, in GB 19147, the cold filter point is included in the standard of diesel for vehicles. The good reduction effect of ethanol on the cold filtration point can explain that the addition of ethanol can improve the low temperature performance of automotive diesel to some extent. the

4 Fire hazard test

4.1 Flash point

According to GB/T 261-1983, the flash point of different base diesel and its ethanol diesel was determined, and the results are shown in Table 11.

Table 11 Flash point/°C of ethanol diesel base oil E0 E2 E4 0# diesel 56 <20 <20 Diesel oil 46 <20 <20 Chang San Diesel 84 <20 <20 Hydrogenated Diesel 74 <20 <20 cracked diesel 52 <20 <20

It can be seen from the data in Table 11 that:

(1) After adding ethanol, the flash point of ethanol diesel rapidly decreases to around the flash point of ethanol (12°C);

(2) The amount of ethanol added has little effect on the change of the flash point, as long as a small amount of ethanol is added, the flash point of ethanol diesel can be greatly reduced.

The reason for this is that the flash point reflects the properties of the light components in the oil. Even if the proportion of ethanol in ethanol diesel is very low (2%), in the test, the ethanol will evaporate quickly, resulting in flash fire . the

The flash point is related to the fire hazard of the fuel. The flash point reduction of ethanol diesel shows that during storage and transportation, ethanol diesel will evaporate more easily in the space of storage tanks and pipelines, thus reaching the explosion limit of the fuel, resulting in flash fire, explosion, etc. the

4.2 Effect of evaporation improver on flash point

Use the two evaporation improvers and one inorganic salt described in 2.3 as evaporation improvers to reduce the flash point of ethanol diesel by reducing the evaporation of ethanol diesel. The flash point of 0# diesel and ethanol diesel with 0# diesel as base oil was tested, and the results are shown in Table 12.

Table 12 Effect of evaporation improver on flash point E2 E4 No additive <20℃ <20℃ Evaporation Improver A 20°C 20°C Evaporation Improver B 23°C 21°C Inorganic salt 20°C 20°C

It can be seen from Table 12 that although the evaporation improver can reduce the evaporation of ethanol diesel, it can slightly increase the flash point of ethanol diesel after adding it. But in general, the evaporation improver has little effect on the flash point of ethanol diesel, and the flash point after adding the agent is still far below the specified value (not less than 45°C) of the ethanol diesel standard for vehicles.

Due to the strong evaporation of ethanol itself, it is very difficult to solve the problem of ethanol diesel flash point. We can only strengthen management during storage and transportation, treat ethanol diesel according to the storage and storage methods of motor gasoline, and prevent safety accidents during storage and transportation. the

5 Other performance tests of ethanol diesel

5.1 Metal corrosion

The copper sheet corrosion of ethanol diesel was measured by GB/T5096-85, and the results are shown in Table 13.

Table 13 Copper corrosion of ethanol diesel base oil E0 E2 E4 0# diesel 1a 1a 1a Diesel oil 1a 1a 1a Chang San Diesel 1a 1a 1a Hydrogenated Diesel 1a 1a 1a cracked diesel 1a 1a 1a

It can be seen from Table 13:

(1) Ethanol will slightly increase the corrosiveness of diesel;

(2) When the ethanol content is not high (<8%), the copper sheet corrosion of ethanol diesel can meet the national standard and meet the requirements for the use of ethanol diesel.

5.2 Determination of sealing adaptability index

Ethanol diesel was prepared with 0# diesel as the base oil, and the rubber corrosion of ethanol diesel was measured by SH/T0305-93. The results are shown in Table 14.

Table 14 Sealing adaptability index of ethanol diesel 0# diesel E2 E4 Diameter before test D1/mm 25.050 25.05 25.050 Diameter D2/mm after test 26.075 26.100 26.125 Diameter expansion percentage SD1/% 4.092 4.192 4.291 Volume expansion percentage SV1/% 8.351 8.549 8.767

It can be seen from Table 14 that with the increase of ethanol content, the sealing adaptability index of ethanol diesel shows a linear upward trend.

The sealing adaptability index is related to the compatibility of rubber in the automobile oil circuit. The increase of the sealing adaptability index indicates that the addition of ethanol will make the sealing performance of the oil worse, and the possibility of swelling, shrinking, hardening and cracking of ordinary rubber becomes larger, and has a direct and obvious relationship with the amount of ethanol added. If ethanol diesel is used as engine fuel, special rubber (such as silicone rubber, fluorine rubber) should be selected as the engine seal as much as possible. the

6 Effect of ethanol diesel on engine power performance

6.1 Test materials and methods

(1) fuel

Comparative fuel: commercially available 0# light diesel oil;

E2: Using commercially available 0# light diesel oil and absolute ethanol as raw materials, the mixed fuel containing 2% absolute ethanol is prepared according to volume percentage.

E4: Using commercially available 0# light diesel oil and absolute ethanol as raw materials, a mixed fuel containing 4% absolute ethanol is prepared according to volume percentage. the

(2) Engine

Weichai WD615 diesel engine, which is widely equipped by the army, is used as the test engine.

(3) Test method

Adopt the load characteristic test and total power test part in GB T 18297-2001 "Automobile Engine Performance Test Method".

6.2 Test results and discussion

6.2.1 External characteristics

Figures 3 to 4 show the external characteristic results of 0# diesel and E2 and E4 ethanol diesel (in each figure, the solid line is the result of 0# diesel, and the dotted line is the external characteristic result).

It can be seen from Figures 3 to 4 that: with the increase of ethanol addition, the fuel consumption rate of ethanol diesel increases, the torque decreases, and the power decreases. And the variation of ethanol-diesel power is almost linear with the amount of ethanol added. the

6.2.2 800rpm load characteristics

Figures 5 and 6 show the torque and fuel consumption rate of the engine burning 0# diesel and different proportions of ethanol diesel at 800rpm.

It can be seen from Figures 5 and 6 that:

At 800rpm, when the ethanol content is low, the torque of ethanol diesel does not change much;

The specific fuel consumption of ethanol diesel did not change much with increasing ethanol content.

6.2.3 1000rpm load characteristics

Figures 7 and 8 show the torque and fuel consumption rate of the engine burning 0# diesel and different proportions of ethanol diesel at 1000rpm.

the

It can be seen from Figures 7 and 8 that:

At 1000rpm, when the ethanol content is low (2%), the torque of ethanol diesel does not change much;

As the ethanol content increases, the torque of ethanol diesel decreases;

When the ethanol content is low, the fuel consumption rate of ethanol diesel has little change;

6.2.4 1200rpm load characteristics

It can be seen from Figures 9 and 10 that:

At 1200rpm, when the ethanol content is low, the torque of ethanol diesel does not change much;

When the ethanol content is low, the fuel consumption rate of ethanol diesel has little change;

6.2.5 1400rpm load characteristics

Figures 11 and 12 show the torque and fuel consumption rate of the engine burning 0# diesel and different proportions of ethanol diesel at 1400rpm.

It can be seen from Figures 11 and 12 that:

At 1400rpm, when the ethanol content is low, the torque of ethanol diesel does not change much;

When the ethanol content is low, the fuel consumption rate of ethanol diesel has little change;

6.2.6 1600rpm load characteristics

Figures 13 and 14 show the torque and fuel consumption rate of the engine burning 0# diesel and different proportions of ethanol diesel at 1600rpm.

It can be seen from Figures 13 and 14 that:

At 1600rpm, when the ethanol content is low, the torque of ethanol diesel does not change much;

When the ethanol content is low, the fuel consumption rate of ethanol diesel has little change;

6.2.7 1800rpm load characteristics

Figures 15 and 16 show the torque and fuel consumption rate of the engine burning 0# diesel and different proportions of ethanol diesel at 1800rpm.

It can be seen from Figures 15 and 16 that:

At 1800rpm, the torque of ethanol-diesel decreased with the increase of ethanol content;

When the ethanol content is low, the fuel consumption rate of ethanol diesel has little change;

6.2.8 2000rpm load characteristics

Figures 17 and 18 show the torque and fuel consumption rate of the engine burning 0# diesel and different proportions of ethanol diesel at 2000rpm.

It can be seen from Figures 17 and 18 that:

At 2000rpm, the torque of ethanol diesel decreases with the increase of ethanol content;

When the ethanol content is low, the fuel consumption rate of ethanol diesel has little change;

6.2.9 2200rpm load characteristics

Figures 19 and 20 show the torque and fuel consumption rate of the engine burning 0# diesel and different proportions of ethanol diesel at 2200rpm.

It can be seen from Figures 19 and 20 that:

At 2200rpm, the torque of ethanol diesel decreases with the increase of ethanol content;

The fuel consumption rate of ethanol diesel has not changed much;

6.2.10 Discussion

Compared to base diesel, ethanol contains oxygen in its molecules. The presence of oxygen will have the following two opposite effects on the work of the engine: On the one hand, the presence of oxygen can lead to a decrease in the content of combustible components (C, H) in the same weight of ethanol diesel, so that the engine torque and The power decreases and the fuel consumption rate increases; on the other hand, the presence of oxygen can lead to more complete combustion of fuel in the engine, thereby improving engine combustion, increasing engine torque and power, and reducing fuel consumption rate.

From the test results, we can see the results of these two opposite effects interactions:

(1) Torque and power

With the same throttle opening, the volume of fuel entering the engine per unit time is the same. The test results show that under different loads at various speeds, the general trend is: when the throttle opening is the same, the torque and power of ethanol diesel are smaller than that of diesel, and with the increase of ethanol content, the decrease of torque and power increases.

It is worth noting that below mid-range (1600rpm), ethanol-diesel has comparable torque and power to diesel when the ethanol content is very low (2%). It shows that at this time, the combustion-promoting effect of oxygen offsets the negative effects brought about by the reduction of fuel content. the

(2) Fuel consumption

The fuel consumption rate is different from the torque and power: in the case of greater engine speed, load and ethanol content, even though the torque and power of ethanol diesel have changed significantly, the fuel consumption rate of the engine has not changed much. The reason may be that although the torque has decreased, the fuel consumption has decreased at the same time.

In addition, whether it is at low speed or high speed, there is always an optimal volume percentage of ethanol. Under this optimal percentage, the fuel consumption rate of ethanol diesel is equivalent to that of base oil, that is, although the same weight of ethanol contains Oxygen cannot be combusted, but due to the combustion-promoting effect of oxygen, the fuel consumption of ethanol diesel is equivalent to that of diesel; when the oxygen content exceeds a certain level, the combustion-promoting effect of oxygen cannot offset the negative effects caused by the reduction of fuel content. Increased fuel consumption. the

The effect of oxygen-promoting combustion is also affected by the engine load. At each speed, as the load increases, the fuel consumption difference between ethanol diesel and diesel decreases. The reason may be that under the condition of large load, the effect of oxygen combustion enhancement is relatively improved. the

Therefore, adding about 1% of butanol, octanol or KCl can reduce the evaporability of the mixed fuel, greatly reduce the evaporation of the fuel, make it difficult to catch fire or explode, and greatly improve the safety during transportation and use. This is actually a very important factor in current use, and many ethanol diesels have not considered this issue. the

Compared with prior art, the beneficial effect of the present invention is:

(1) The quality requirements for basic diesel are low, basically applicable to all diesels;

(2) Compared with basic diesel, it basically has no effect on the power of the engine;

(3) Reduce the evaporation of the mixed fuel and improve the safety of transportation and use;

(4) Improve and optimize the miscibility and water solubility of diesel and ethanol.

Description of drawings

Fig. 1 is the distillation diagram of ethanol diesel oil;

Fig. 2 is the Reid method saturated vapor pressure diagram of different proportions of ethanol diesel;

Fig. 3 is the external characteristic map of 0# diesel oil and E2 ethanol diesel oil;

Fig. 4 is the external characteristic map of 0# diesel oil and E4 ethanol diesel oil;

Fig. 5 is the torque-throttle relationship diagram of ethanol diesel under 800rpm;

Fig. 6 is the fuel consumption rate-throttle opening relationship diagram of ethanol diesel at 800rpm;

Fig. 7 is the torque-throttle opening relationship diagram of ethanol diesel under 800rpm;

Fig. 8 is the fuel consumption rate of ethanol diesel oil under 1000rpm-throttle opening relationship diagram;

Fig. 9 is the torque-throttle opening relationship diagram of ethanol diesel under 1200rpm;

Fig. 10 is the fuel consumption rate of ethanol diesel at 1200rpm-throttle opening relationship diagram;

Fig. 11 is the torque-throttle opening relationship diagram of ethanol diesel under 1400rpm;

Fig. 12 is the fuel consumption rate of ethanol diesel at 1400rpm-throttle opening relationship diagram;

Fig. 13 is the torque-throttle opening relationship diagram of ethanol diesel under 1600rpm;

Fig. 14 is the fuel consumption rate of ethanol diesel at 1600rpm-throttle opening relationship diagram;

Fig. 15 is the torque-throttle opening relationship diagram of ethanol diesel under 1800rpm;

Fig. 16 is the fuel consumption rate of ethanol diesel at 1800rpm-throttle opening relationship diagram;

Figure 17 is the torque-throttle opening relationship diagram of ethanol diesel at 2000 rpm;

Figure 18 is the fuel consumption rate of ethanol diesel at 2000 rpm-throttle opening relationship diagram;

Figure 19 is the torque-throttle opening relationship diagram of ethanol diesel at 2200 rpm;

Figure 20 is the fuel consumption rate-throttle opening relationship diagram of ethanol diesel at 2200 rpm.

Detailed ways

The present invention is further described below in conjunction with embodiment. Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 ethanol 2 liters 2L 2L Finished Diesel 98L 58L 38L 28L straight run diesel 30L 40L 70L 98L secondary processed diesel 10L 60L 58L 98L Butanol 1L 1.1L 1.2L 1L 1.1L 1L 1.2L Isoamyl alcohol 0.3L 0.3L 0.4L 0.35L 0.35L 0.3L 0.4L Butanol 5L 4L Isooctyl alcohol 5L 4L 6L Isoamyl alcohol 5L 6L Butanol 0.8L 1.2L octanol 1L 0.8L 1.2L KCl 0.8kg 1.2kg Ethylene glycol ether 0.1L 0.3L 0.2L Ethylene glycol monomethyl ether 0.2L 0.2L 0.3L 0.1L industrial alcohol 2 liters 2 liters 2 liters 2 liters

the

Claims (5)

1. A kind of E2 ethanol-diesel blended fuel, comprises the raw material mixing of following parts by volume and makes: 2 parts ethanol Diesel 98 parts Ethylene glycol ether or ethylene glycol methyl ether 0.1~0.3 parts The ethanol is absolute ethanol or industrial alcohol; the diesel oil is one or a mixture of finished diesel oil, straight-run diesel oil, and secondary processed diesel oil. 2. The E2 ethanol-diesel blended fuel according to claim 1, characterized in that: 0.8-1.2 parts by volume of butanol or octanol is added to the E2 ethanol-diesel blended fuel. 3. The E2 ethanol-diesel blended fuel according to claim 1, characterized in that: 0.8-1.2 kg of KCl is added to the 100LE2 ethanol-diesel blended fuel. 4. The E2 ethanol-diesel blended fuel according to claim 2 or 3, characterized in that: 1-1.2 parts by volume of n-butanol and 0.3-0.4 parts of isopentyl are also added to the E2 ethanol-diesel blended fuel Co-solvents composed of alcohols. 5. The E2 ethanol-diesel blended fuel according to claim 4, characterized in that: 4 to 6 parts by volume of n-butanol, isobutanol, isooctyl alcohol or isoamyl alcohol.

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