As a representative of new-type power cars, are fuel cell vehicles and electric vehicles better than others? When we discuss the subject is limited to fuel cell vehicles and electric vehicles alternative: from the perspective of the principle of hydrogen fuel cell vehicles, the ultimate use of electric energy to drive the motor, compared with electric vehicles, only the energy carrier is different; From the perspective of energy saving, it is more ideal to minimize the number of energy conversions; from the perspective of industrial development, "mechanical drive" to "electrical drive" are in line with the direction of scientific and technological development; from the perspective of development, electric vehicles are the future of wireless Transmission of electricity reserves space for development. In this case, instead of choosing hydrogen fuel cell vehicles, it would be better to invest research resources in the direction of electric vehicles in one step. The following describes the relevant knowledge about fuel cells and pure electric vehicles. I. About Fuel Cell Vehicles (A) The working principle of fuel cells and the preparation of raw materials The basic principle of a fuel cell is to use the energy generated by the combined reaction of hydrogen and oxygen to generate electricity. The generated electricity can be used to maintain the operation of the spacecraft (such as the "Apollo Project" spacecraft) and can be used for home use (such as the home power supply system used by Tokyo Gas in Japan). If it is used to drive a car, it becomes a fuel cell car. From the point of view of fuel sources, fuel cells include pure hydrogen and liquefied natural gas. The main component of LNG is methane (CH4), which uses electricity generated by the oxidation reaction of methane (not necessarily through the combustion process). Carbon dioxide is produced during the reaction, but no nitride is produced, which is relatively “cleanâ€. However, this method is mainly used for home-use fixed devices, so the larger size. This method is not the focus of this topic, so leave it alone. (II) Preparation of hydrogen Hydrogen is mainly obtained in the following ways: 1. Byproducts of industrial production Such as hydrogen produced in the process of chemical alkaline production; Hydrogen produced in the fermentation reaction Such as compost, hydrogen produced in the sludge due to the fermentation reaction 3. Hydrogen generated from electrolyzed water Use electricity to break down water, producing hydrogen and oxygen. This is the reverse process of the fuel cell reaction. (III) Environmental protection of fuel cell vehicles The fuel cell car only discharges water during driving, and is considered to be an "environmental" type of transportation. Is this really the case? When we discuss its environmental protection, we must not only consider the fuel cell vehicle itself, but also focus on the entire process of hydrogen production, hydrogen storage, distribution, and use of this system. Only through the evaluation of the entire system can we judge the pros and cons of its environmental protection. As mentioned before, the fuel for the fuel cell car, hydrogen, is produced using electricity. In the process of producing hydrogen, electricity consumption is very high. Although it can generate electricity from renewable energy sources such as solar energy, hydraulic power, and wind power, it is mainly carried out through fossil fuels such as oil and coal. In other words, power generation itself will bring environmental pollution. The storage of hydrogen is a very difficult matter. Hydrogen gas is small in size and bulk, so it must be compressed with high pressure and stored in a closed container (the container pressure of Toyota's mirai is 700 atmospheres). Hydrogen is ranked first in the periodic table, that is, hydrogen molecules are the smallest molecules. Hydrogen molecules can easily escape through the tiny holes in the storage vessel wall. The high pressure of the storage container exacerbates this process. When hydrogen is added to a “gas stationâ€, due to the frequent use of hydrogen charging equipment, the tightness of all the valves at 700 atmospheres cannot maintain the design state for a long time, so it is inevitable that some hydrogen will be lost during this process. So far, we have not been able to find quantitative data on the extent of hydrogen spitting after multiple storage and transportation processes from the preparation of hydrogen to the oxidation reaction. At the cosmic scale, the gravity of the Earth is not enough to attract hydrogen. The scattered hydrogen will eventually enter the space. The hydrogen fuel cell cycle of “breaking water into hydrogen and oxygen†→ “hydrogen peroxide into water†will bring about a drop in the overall hydrogen content (water content) of the earth (although this process is extremely slow)! From the hydrogen evolution in the hydrogen fuel cell vehicle system, we see a "chemical energy of fossil fuels" → "heat energy" → "electric energy" → "hydrogen chemical energy" → "electric energy + heat energy" → "vehicle kinetic energy" This process of energy form conversion. Please note that there is a problem of conversion efficiency in the energy conversion process (the lost energy is basically converted to thermal energy). In other words, the more energy conversions, the greater the waste of energy! Theoretically speaking, if the hydrogen consumed from a unit of fossil fuel energy is consumed, the work done in the final stage of the hydrogen-oxygen chemical synthesis reaction (which can be understood here as the distance to advance the vehicle) is less than the energy content per unit of quantified fossil energy. If you do the work, you can't say that the hydrogen fuel cell car has good environmental protection! (d) An issue that is not noticed When discussing the environmental protection of hydrogen fuel cell vehicles, it is often overlooked that the vehicle's drainage problems. The principle of a fuel cell is that hydrogen and oxygen react to produce water and generate energy. This means that the hydrogen fuel cell car drains while driving. How much water will be discharged in this process? We can use Toyota's mirai as an example to calculate simply how much water will be generated when all the hydrogen is used up: Basic parameters Hydrogen storage tank capacity: 122.4 liters (60 liters for front tank and 62.4 liters for rear tank) Air pressure: 700 atmospheres Volume under normal pressure (for ease of calculation, neglect of temperature changes): 122.4 liters × 700 = 85,680 liters Molar amount of hydrogen: 85,680 L/22.4 L (per mol) = 3,825 mol Water molecular weight after oxidation: 3,825mol 1 mol water molecule weight: 18 g 3,825mol water molecule weight: 68,850g Cruising distance with hydrogen: 650 km Water produced per kilometer: 68,850 g/650 km = 106 g/km That is, the amount of water evaporated by the oxidizing heat is removed during running, and approximately 100 grams of water is generated per minute. If the speed is 60 km/h, then for every 5 km, about 500 g of water will be produced. Everyone can give it a try, take a 500ml pure water bottle, fill it with water for 5 minutes, then the flow of the tap to open. When a hydrogen fuel cell vehicle accounts for a certain percentage of vehicles in the vehicle, the amount of water discharged by the vehicle will be higher than the amount of water evaporated and dredged, and water will accumulate on the road. In combination with the current state of road dust accumulation in China, splashing mud on the vehicle body cannot be avoided. And in the winter in the north, the road will even turn into a skating rink! Think about it: When you are driving on the highway, in front of a "sprinkler", what would be the situation? In summary, compared with ordinary automobiles, hydrogen fuel cell vehicles such vehicles do not produce nitrides and carbon particles during exhaust gas removal, and it is difficult to say whether they can provide “positive energy†in terms of environmental protection. Second, on the electric car (a) The status of electric vehicles As the name implies, electric cars are cars powered by electricity. This does not include hybrid vehicles. It refers specifically to the use of purely electric power to drive, and it is not necessary to have a wired power supply (such as trams and trolleybuses) at any time during the exercise. Modern electric vehicles install the driving motor to the axles of each driving wheel, and can precisely control the power distribution and rotation speed of each wheel while driving. Therefore, transfer cases, differentials, and EBD (Electronic Power Distribution System) used in some high-end automobiles can be omitted, which greatly reduces the cost of the vehicle. After cutting down the engine and transmission system, the interior space will increase a lot. If the battery is arranged near the chassis can reduce the center of gravity, greatly improving the stability of the vehicle. At the same time, due to the use of a DC motor, the kinetic energy at the time of deceleration of the vehicle can naturally be recovered and the economy is better. Motors have the advantage of large torque, so the acceleration performance of electric vehicles is better. Tesla’s 100-km speedup is only 3.1 seconds. (B) The Difficulties of Electric Vehicles Whether it is a hydrogen fuel cell vehicle or an electric vehicle, it is necessary to build a new "gas station", so this question can be omitted. The current marketization of electric vehicles mainly has the following problems: 1. The problem of vehicle cost In the cost of electric vehicles, the proportion of storage batteries is very high, accounting for about 1/3-1/2 of the total cost of the entire vehicle. 2. Battery capacity and life problems The current automotive rechargeable battery is a lithium battery, and the short cruise time is an important issue. Now the goal of the manufacturer is to reach or exceed the cruise mileage of the petrol engine. At present, Nissan Motor Co.'s electric car (two-box car) can use nearly 250 kilometers after being fully charged. 3. Charging time problem Longer charging time is another weakness of electric vehicles. Hydrogen fuel cell vehicles "refuel" time is about 3 minutes, roughly the same as gasoline vehicles. The charging time of an electric vehicle is often several tens of minutes (Nissan's charging station for electric cars takes 20 minutes to charge 80% of the electricity, but it takes longer to fully charge electricity). Although the home-style plug charging method can use evening charging, the temporary charging on the outside still cannot correspond. In order to solve the above problems, Nissan Motor Co. of Japan proposed a solution. The main points are: 1. When the user purchases a car, only the vehicle body is purchased; 2. After the car is purchased, "lease" the battery; 3. "Gas station" prepares a large number of batteries and is responsible for charging; 4. When the user needs to "refuel", to the "gas station" replace the charged battery; 5. The user pays for the electricity charge up to the current mileage in accordance with the last battery replacement. This approach not only solves the problem of high battery cost, but also solves the problem of long charging time. Users do not have to consider the burden of battery aging. When the "gas station" is spread to a certain extent, the problem of small battery capacity does not exist. The disadvantage is that all cost burdens are imposed on manufacturers and service providers, and one-time investment is too large. Square Corn Thresher,Maize Thresher Machine,Small Electric Corn Sheller,Automatic Corn Shucker Hunan Xinta Machinery Manufacturing Co., Ltd. , http://www.xyagriculture.com