1. Characteristics of fuel cells
(1) High energy density, the specific energy can reach about 200W·h/kg. PCEV requires that when hydrogen is used as fuel, the mass specific power of the battery is not less than 150W/kg; when methanol is used as fuel, the mass specific power of the battery is not less than 100W/kg.
(2) Generally operated under normal temperature conditions, it is easy to start quickly when the temperature is around 80°C, which reduces the impact of temperature on fuel cell materials, improves battery performance, and extends battery life.
(3) It can work continuously and is suitable for partially meeting the characteristic requirements. These superior performances bring great convenience to the use of PEMFC on FCEV.
(4) The voltage of a single battery is high and it is an ideal power source for electric vehicles, which is beneficial to reducing the maintenance quality of electric vehicles and reducing the cost of using electric vehicles.
(5) There are three types of dyes in fuel cells: hydrogen, methanol and gasoline. According to the power generation principle of fuel cells, hydrogen is the most ideal fuel because hydrogen can directly participate in electrochemical reactions. The product of a hydrogen fuel cell is only clean water vapor, which does not cause any pollution to the environment.
2. Application of fuel cells. The application fields of fuel cells as mobile power sources are divided into two categories. One is that it can be used as portable power supply, small mobile power supply, vehicle power supply, etc. It is suitable for military, communications, Computers and other fields to meet the needs of emergency power supply and high reliability and high stability power supply. Practical applications include mobile phone batteries, notebook computers and other portable electronic devices, military backpack communication power supplies, satellite communication vehicle power supplies, etc.; second, they are used as power sources for bicycles, motorcycles, cars and other transportation vehicles to meet environmental protection requirements for vehicle emissions. . Judging from the current development situation, PEMFC is the most technologically mature power source for electric vehicles.
3. Internationally, the authoritative organization in the field of fuel cell research and development is Ballard Energy Systems Company of Canada. In 1996, H-Power Company of the United States developed the world's first large vehicle with fuel cells as the power source. bus. In recent years, our country has also attached great importance to the research and development of fuel cell electric vehicles and has been listed as a national key scientific and technological research plan. Shanghai Shenli Company, Fuyuan Fuel Cell Co., Ltd., Tsinghua University, and Dalian Institute of Chemical Physics, Chinese Academy of Sciences have respectively developed prototypes of sightseeing buses and minibuses, and their performance is close to or reaching the international advanced level.
4. In addition to being suitable for transportation power supply, fuel cells are also very suitable for stationary power supply. It can be interconnected with the power grid system and used to adjust the peak value of the power grid. It can also be used as a power supply for islands, mountainous areas, remote areas or as a power supply system for national defense (civil air defense).
5. Multiple fuel cell generators can be connected to form a distributed power supply system. The decentralized power supply system has the following advantages:
(1) It can eliminate the need for power grid lines and distribution dispatch control systems.
(2) It is conducive to combined heat and power (because PEMFC power stations are noise-free and can be installed nearby, and the heat generated by PEMFC power generation can enter the heating system), which can make the total fuel utilization rate as high as more than 80%.
(3) It is relatively less affected by wars and natural disasters, and is especially suitable for active protection needs under modern war conditions.
(4) By reforming natural gas and coal gas to produce oxygen, existing infrastructure such as natural gas and coal gas supply systems can be used to provide fuel for fuel cells.
(5) Hydrogen production through renewable energy (hydrogen production by electrolysis of water, hydrogen production by solar electrolysis, and biological hydrogen production) can form a recycling system (this recycling system is especially suitable for remote areas), making the system Construction and operating costs are reduced. It is generally believed internationally that with the promotion and utilization of fuel cells, the development of decentralized power stations will be a trend.
6. Because the fuel cell has low operating temperature, low infrared radiation, no vibration, and no noise, it is particularly suitable for use as a modern military power source. In August 1998, the U.S. Department of Defense pointed out in a report submitted to the National Defense Committee of Congress: Mobile power is one of the five most basic elements of permanent defense facilities; the rapid evolution of fuel cell power generation technology to replace conventional power generation devices has given rise to future power generation systems. The use of hydrogen as the main fuel opens the way; due to the high energy conversion efficiency (more than 60%) and extremely simple operation and maintenance, the fuel cell generator makes the application of hydrogen energy as the main fuel extremely reliable and efficient.
Therefore, changing the combat fuel to hydrogen will result in a more efficient and reliable power generation system, lower emissions, lower noise, greatly reduced thermal radiation and infrared imaging, and facilitates camouflage and concealment operations.
7. The many superior properties of PEMFC generators make it portable in aerospace and super mobile equipment, underwater submarines, military engineering, communications engineering, vehicle power supplies, and individual soldiers and units (detachments). It has excellent application prospects in power supplies, remote areas, coastal defense posts and civil air defense projects. As early as the 1960s, the National Aeronautics and Space Administration (NASA) and General Electric Company (GE) jointly developed fuel cell generators and used them for many flights of the Gemini satellite program. Especially after the Nafion membrane was adopted in 1968, the life of the fuel cell generator used on the launched biosatellite has reached 57,000 hours in the laboratory. Later, NASA cooperated with Hamilton Standard Company to develop an RPC (regenerative fuel cell) system, which was intended to be used in conjunction with a solar power generation system to form a power source for Mars exploration vehicles or lunar bases (solar electrolysis water device power 35kw, PEMFC generator power 25kw) The U.S. Air Force also signed an agreement with Treadwell Company to study the RFC system for satellites (fuel cell power 12kw, voltage V).
8. In terms of Hyper Mobile Equipment (HMU) applications, NASA and EPSI have cooperated to develop a 200W·h energy PEMFC system that uses metal hydride hydrogen storage to replace the rechargeable ones used in existing equipment. Batteries can effectively improve energy storage density, one-time charging energy, cycle life, and charging speed.
9. An important use of fuel cells in the military field is as a power source for naval ships. As an air-independent propulsion power (AIP) source for submarines, PEMFC generators have the advantages of high efficiency, low noise, and small infrared radiation compared with Stirling engines and closed-cycle diesel engines. They can carry the same mass or volume of fuel. When using gas, the submarine has the strongest endurance (about 2 times that of the Stirling engine) and there is no pollution. Therefore, the fuel cell is the best choice for the submarine AIP system. Germany began researching fuel cell generator submarines in 1980 (the earliest in the world). Currently, Germany is able to produce 212 and 214 model submarines based on fuel cell generators. The U.S. Navy has cooperated with AP Company to develop a fuel cell generator using hydrogen produced by diesel reforming as the hydrogen source, and has also cooperated with Treadwell Company to design and manufacture a fuel cell power supply for underwater detectors.
10. The many advantages of fuel cells make them have excellent prospects in important civilian facilities such as smart buildings, hospitals, hotels and national defense (civil air defense) fields. At present, the power supply systems in these places all use external power as the main power supply and diesel generator sets as the supplement. When the external power supply is damaged and the diesel generator set is activated, it will be unsuitable for use in future high-tech wars due to its smoke emissions, poor concealment, large vibration, high noise, poor environmental performance and many other shortcomings. Therefore, research on PEMFC-based power generation systems can effectively utilize hydrogen energy to achieve environmental protection, which is of extremely important significance to civilian power supply and national defense construction.