【 Weak current College 】 energy and technology

Overview

"Energy conservation, protection of resources" is our pursuit of sustainable development in the new era of great strategic means of guarantee and, since reform and opening up, China's economy remains high at 8% growth rate, already on the rapid growth in the supply of energy has become the bottleneck of economic growth, energy efficiency has become a national economic development of a long-term strategy, businesses are increasingly recognizing the importance of saving energy.

Conserve energy as the name suggests is to save energy consumption. Starting from energy production to the final consumer, in its various aspects, such as mining, transportation, processing, conversion and use to reduce losses and waste. From an economic sense, through rational use, scientific management, technical progress achieved with minimal energy consumption and maximize economic efficiency. World Energy Conference survey of energy saving Committee shows that developing energy utilization of only 20% ~ 30%, industry developed and only 40% to 50% of the global energy saving potential is great. If the world's energy consumption by various technical means savings of 10%, then the savings of energy will be more than the world all hydropower station can provide electricity combined. International energy sector departments or even energy known as the fifth largest energy, coal, petroleum and natural gas, hydroelectric, nuclear power's energy-saving side-by-side, of great significance.

Although China's energy resources are abundant, but the per capita amount is lower, and consumption, and wasted. Energy conservation attach great importance to our country, in 1997, at its eighth session of the Standing Committee at its 28th session, on 1 January 1998 formally implemented the People's Republic of China Energy Conservation Act. The Act concerning energy management, rational use of energy resources, promoting energy-saving technology, legal liability, etc.

Energy-saving technology generally include the following three areas: one, enhances the existing energy utilization; second, the selection of new materials in order to achieve the purpose of energy saving; the third is the study of energy storage technologies, will temporarily use of energy storage.

First, China's energy demand forecasting

2001 national energy expenditure of 1.25 billion yuan, accounting for 13% of GDP, according to the current trend of development, by 2020, primary energy demand will reach 3.5Gtce, coal demand up 610Mtce 2.9Gtce, oil. Such a huge demand for coal supply, oil, security and environment are very serious problems, our energy base can be supported?

Deputy Director of the development research center of State Council, Chen Qing Tai energy should be put in the primacy of the energy strategy, that is, in order to meet the growing demand for energy-saving than increased energy supply more priority, in order to establish an important strategic position of energy saving, it is recommended that you save the resources raised to the height of a basic national policy, "population control, conserve resources, protect the environment" as the new era of basic national policy.

Second, China's energy efficiency and advanced countries of gap

In recent years, China's "insist on resource development and savings, the savings come first" principle, the energy saving achieved remarkable results. But many enterprises in China have not been fundamentally out of extensive management, outstanding issue is the quality and efficiency of economic growth is not high, the main reason for this lies in the structure, poor product quality, energy, raw material consumption, waste, energy use, specifically reflected in:

First, is the product of high energy consumption, major energy-using products unit energy consumption than developed countries high 30 ~ 80%, an average of 40%. Recent technology energy-saving potential for 120Mtce.r>
Second, is the output of high energy consumption, China's economy energy intensity (output power) is one of the most high, about Korea 3.7 times United States 7.4 times Japan 12.8 times the world average of 4.3 times (here's economic structure, exchange rates, etc. not comparable factors), the recent output energy-saving potential of up to 300 ~ 400Mtce, compared with developed countries, we have a great gap, so there are relatively large in our description of energy-saving potential, to our province, for example, if the annual resource consumption savings of 1%, at least you can get 70 billion in economic benefits.

3. energy-saving technology

1. improving energy utilization

For energy utilization, popular, mainly energy efficiency, i.e., the energy is the energy use of some people with energy contained the ratio of the total energy. The greater the ratio, the energy contained in total energy use by people in some of the more, the higher the energy utilization.

At present, for various reasons, the use of conventional energy efficiency is very low. Only to thermal power, for example, the efficiency of only 30% to 40%. For example, coal combustion produces 100J calories, of which only 30 ~ 40J's heat into electricity, while the remaining 60 ~ 70J thermal energy through a variety of approaches in transformation of lost in the process. If you can substantially improve the conventional energy utilization, can effectively reduce the consumption of conventional energy resources, so as to achieve the purpose of energy saving.

(1) heat cogeneration

We all know that. Power by burning fuel generated heat energy to water into a high temperature and high pressure steam, high temperature and high pressure steam turbine generators for impact. Through the turbine steam still has a very high temperature, if not recycling, water vapor in a considerable part of the energy will be wasted, if directly into rivers, also produces heat pollution. Therefore all countries in the study of this technology. The generator, heat exchanger close together, so that the whole system to generate electricity and heat to the outside world, the collection of hot water can be recycled. This method enables the heat recovery and heat were fully utilized, can be a lot save fuel energy utilization increased 15% to 30%.

(2) circulating fluidized bed technology

In the future for quite a long time, coal is still the main energy of human existence. Therefore, improving the utilization of coal in energy-saving technology in occupies an important position, it is important to long-term research.

In our country, coal is used primarily for thermal power plants, industrial boilers and civilian fuel. As a result of combustion equipment behind, causing the burning rate is low, while producing significant amounts of harmful gases and dust, environmental pollution. Therefore, the study of coal-fired technologies is increasing the importance of coal utilization.

If coal utilization increased by 10%, then a year to around, thus saving coal 10t its coal saving effect is very significant. Circulating fluidized bed technology is a new generation of more mature coal technology, it is the coal and adsorption sorbents to join in the bed of the combustor, and the bottom from the boiler to the combustion chamber so that the compressed air blowing in pulverized coal combustion spread throughout the room vulcanization combustion. Combustion of coal and coal after mash-up, and then returns to the secondary combustion chamber, the results can be combustion efficiency as high as 99%. Therefore, this technology is an efficient, clean, you can burn the inferior coal, etc., present 400t/h circulating fluidized bed boiler has been put into use, some developed countries being built 800t/h of circulating fluidized bed boiler and 10kW genset 2.35 × auxiliary power plant.

(3) fuel-saving technology

The oil and waterby a 2: 1 proportion mixed up with a frequency of more than 2 × 10Hz ultrasonic will water and oil mixture evenly into emulsions, emulsion of small water droplets are oil molecules surround the oil increases the surface area of millions of times, thereby greatly improving the burning speed. And burns, surrounded by the oil molecules heated small water droplets will burst, it broke the surface of the reservoir, so that the oil surface area further expanded, thus greatly increasing the utilization of oil combustion. Moreover, this mixed fuel energy to produce than single-use oil, and they almost do not produce smoke and ashes, is really two birds with one stone. Other fuel-saving technology is in gasoline mixed in 4% hydrogen, as an automobile engine fuel, saving up to 40% for gasoline. Recently someone discovered that kerosene, gasoline, diesel fuel after magnetization, changed the fuel ignition, viscosity and other physical properties that diminish the gravity of the oil molecules so that oil is easy to form a mist, allowing oil to complete combustion. Using magnetic oil can save nearly 20% of the fuels, energy-saving effect is considerable.

(4) electronic energy-saving

In the large electrical devices use power electronics technology, you can also get significant energy saving effects. The so-called power electronics is a power semiconductor device as the core, plus the power exchange technology, control technology, electronics and computer technology of integrated high-tech, it has developed into an important electromechanical technology.

Current second generation power semiconductor devices for pressure resistance can be as high as above, but allows 4500v through current also to 2500A above, a fully capable industrial and mining enterprises, civil electric power and other occasions of automatic control. Using power electronics control motor, the energy savings from 30% to 50%. For example, one of the industrial boiler of the 20t fan, power technology transformation, the annual saving 2.5 × 10kW · h; Beijing State cotton factory adopted after saving power electronics 52.35%.

Another effective way to save energy is the conversion technology. Frequency of two kinds, one kind is the mechanical conversion, electronic frequency. Inverter is designed to change the AC frequency, use of electrical equipment in the most economical State run, so as to achieve the purpose of saving power.

Mechanical conversion by two (three phase) induction motor. One motor stator windings in the three-phase AC power, then, in the motor rotor coil around a rotating magnetic field, the frequency of rotation of the rotating magnetic field is equal to the frequency of the alternating current. Because the motor rotor by wire-wound, so when the stator coil produces the rotating magnetic field and rotor coil produces the induced current, current is rotating magnetic field and magnetic moments's role, forcing the rotor coils and rotate rotating magnetic field in the same direction. If the motors with a little modification, with two sliding ring the rotor coils of induced current in the nutty, with another motor to drive the motor rotor, practice shows that leads to changes in the frequency of the induced current, with rotor speed changes, and the rotor and the rotating magnetic field and the direction of rotation, the induced current changes in frequency of smaller, two opposite direction of rotation, the induced current changes in frequency. If you change the frequency of alternating current in the future to other motor, you can adjust other motor speed, this technique is called frequency.

Electronic frequency is similar to the signal generator, its principle is to use current L-C oscillation circuit, so as to achieve the purpose of changing the AC frequency. For example, a building of automatic water supply equipment, if not using frequency conversion technology, so as long as someone with a water supply equipment isin full working order, but the use of the frequency conversion technology, water supply equipment will be under water consumption per time unit sized motor speed, water usage hour motor go slowly when heavy water motor go fast, so as to achieve the purpose of energy saving.

At present the domestic market of the frequency inverter air conditioners, refrigerators and other products, is based on the temperature level to control the speed of the compressor, so these products are energy-saving products.

2, material-saving

Where to save energy-saving materials materials call. To select materials for energy purposes method called material and energy saving. To date, has found the energy-saving materials up to thousands of species. Here are a few of them, as well as the application of these materials after the energy saving effect.

(1) of amorphous Fe-based alloy

Amorphous Fe-based alloy is an iron-basedTo raw material of amorphous metal. Typically, all metals are crystals, crystal molecules are arranged there is a certain law, since the metal of the micro-structure, that makes metal with good electrical conductivity, but sometimes people do not need this kind of electrical conductivity. For example, for the production of silicon steel transformer core material is in the iron mixed with a small amount in the uniform of silicon, mixed into Silicon aims to improve the capacity of magnetic iron core, while reducing the ability of core of conductive, and in order to further reduce the ability of core of conductive, people made of silicon steel sheet, and then use the many pieces of silicon steel sheet pile of synthesis of a core and tablets and tablets with insulation adhesive bonding, even so, the transformer at work, the core by the alternating magnetic field in each piece of silicon steel due to electromagnetic induction phenomenon resulting from the induced current, this part of the induced current because people cannot take advantage ofit is wasted wasted, this is what we usually say Eddy current losses.

In order to further reduce the Eddy current losses, people developed the amorphous material, this material is melted State of liquid metal in an extremely rapid cooling (10 ~ 10 °/s). Due to cooling too fast, the metal atom could arrange into orderly structure, has solidified liquid metal, liquid-level atom in no order is preserved, formed like a glass-like amorphous metal. This amorphous metal magnetic ability is very strong and very weak electric capacity, use it for transformer, Eddy current losses only ordinary silicon steel cores of 25%, thus greatly saves energy. Moreover, the same performance comparison of the two transformers, amorphous core transformer quality than ordinary transformer is much smaller, small volume, and temperature rise of working time. For example, a capacity of up to 3 x the transformer 10VA via AC frequency application for 400Hz, amorphous cores than ordinary transformer volume decrease of 17%, weight decrease of 46%, 85% of the exciting current smaller, lower temperature rise 50% ~ 60%, the comprehensive efficiency as high as 98.5%.

Currently, the United States and Japan in research on amorphous materials. According to statistics, the use of transformers throughout Japan every year produces Eddy current losses up to 10kW 3.6 × · h, if you swap the amorphous core transformer, Eddy current losses can be reduced to the 1.8 × 10kW · h, and savings in electrical energy can meet a 100 million households in urban use.

(2) aluminum

Aluminum alloy used in automobile manufacturing, its primary purpose is to reduce the weight of the car, thus increasing vehicle payload. As we all know, the auto industry cannot be separated from the steel, automotive weight more than 80 per cent was accounted to iron and steel. If you are using aluminum instead of steel, you can significantly reduce vehicle weight, thereby reducing the consumption of non-functioning car, the purpose of achieving energy saving. Has anyone done a test, if a car use 50kg aluminum, can reduce the weight of the car, allowing each 116kg kilometers around fuel consumption reduced to a 6g years traveling 1 million meters of calculation, the annual fuel consumption will reduce 60kg. If all the cars have different degrees of aluminum alloy for parts, fuel-saving effect is very large. Germany of a car company manufacturing of Porsche Cars, each car use aluminum has been as high as $ 236kg, not only reduces the vehicle's weight, reducing energy consumption and improves the vehicle's performance. If the aluminum mixed in magnesium, copper and other metals, to make the impact resisting performance aluminum alloy and steel similar, has become the preferred car bumper.

(3) no filament and long life-saving lamp

When the lamp connected to AC power, the oscillator, the amplifier will produce a high-frequency electromagnetic oscillation, the high-frequency electromagnetic oscillation is set in bulb in a special issue of the transmitting antenna, the formation of high-frequency radio waves within the bulb, the radio waves can make the necessary and sufficient in bulb mercury vapor generation within the plasma ionization. A large number in a high energy level of the mercury atoms occurring radiation transitions will release a lot of UV radiation, ultraviolet bulb of painting on the wall of the fluorescent substances absorb can emit visible light. This no filament bulb, so there is no heating element consumption, thereby increasing the luminous efficiency. Not only that, because of the omitted tungsten filament do, so greatly extend the life of the lamp. A normal incandescent lamp normal life about 1000h, a fluorescent tube in normal life span of about 7000 ~ 10000h, and this energy saving lamp life of up to 14 years, this kind of light-emitting efficiency is Mandarin incandescent lamps 4 x, costs only for the same brightness incandescent 1/3 or so. Somesay it is a light bulb in the history of a major breakthrough, perhaps in the near future to become a major tool for human lighting.

3. energy storage technology

If a city in the electricity consumption peak electricity is electricity trough 2 times, then give the city power supply of the power plant's total installed capacity, must be designed according to the peak power consumption, and the electricity trough (such as late at night), almost half of the installed capacity of power plant are wasted, this not only wastes a lot of energy, but also to the power grid of a negative impact on safety. To resolve this issue, people naturally think of the use of electric energy storage.

However, the power belongs to the process of energy, not to be wasted, like water, is not easy to directly store. Therefore you must put the energy into the energy of the other makes it easy to store. This technique is called peak load shifting energy storage technology that uses electricity trough the surplus of energy storage in power at the peak and then stored energy into electrical energy to compensate for the lack of electricity.

(1) ice storage technology

We all know that heat is the energy of a manifestation, in a sense, the cold is the energy of a form. Ice cold, as the name suggests is ice cold store, when you need to release the cold, ice absorbs heat from the surrounding objects, in order to achieve the objective of the body temperature. Daily life, Industrial and agricultural production, Commerce, tourism and other industries that require large amounts of cold, especially during the hot summer, cold place more. Usually people are taken with air conditioners, refrigerators and other electrical refrigeration and cooling methods, so as to increase the burden of the power plant, and many large power plants are thermal power plant, the issue of power, the consumption of fossil fuel more pollution also. To avoid these situations occur, people think ofelectricity at night, with low period of excess power refrigeration power plant, by day and then made some place of ice to cool down, so as to achieve open air conditioner air conditioning or less. This can reduce electricity consumption during the day, which greatly saves generator installed, played a role in saving energy. Moreover, it also reduces the generator installed, even less to build power plant, also reduces emissions of harmful substances, improvements in the quality of the environment.

In the early 1970s, developed countries began to study on ice storage technology. The 80 's to start the application. Today, ice storage technology as an electricity peak load shifting means, has been widely used in building internal cooling and industrial cooling. Our country is also actively promote and intensify research on ice storage technology.

(2) carbon dioxide energy storage technology

Use carbon dioxide energy storage method is to use electric power plants in the Valley, redundant power for driving large compression type

Refrigeration system, the gaseous carbon dioxide frozen into solid carbon dioxide, and then with solid carbon dioxide to gaseous ammonia cooling for liquid ammonia. Wait until the peak electricity use, so that the liquid ammonia heat absorbing gasification and gas turbine generator to produce electricity. This system's biggest advantage is a small footprint. For example, a pumped storage power station, each storing electrical energy 1000kW · h, volume of the reservoir for 140m, and carbon dioxide energy storage systems storage of electrical energy, as long as the floor space 28m is sufficient. In addition, carbon dioxide and energy storage system during short, environmental impact is small, the site is easy to select, and other advantages.

IV. energy measures

According to reports developed advanced enterprise power-saving potential of 20%, China's average about 40% of the individual up to 50% energy saving potential is seen very huge, it is generally estimated that the total saving benefit, through the Organization of management can receive approximately 30%, through improved process, processing methods and implement some basic free technical measures can receive approximately 40%, by transforming or increase device and consume a larger investment can receive approximately 30%. Obviously, should give priority to measures of organizational management and technical measures.

Factory-saving energy-saving can be divided into management, energy-saving and power-saving technology structure in three ways. Management power saving by improving and strengthening management and evaluation, to mining potential, reducing waste of electricity-saving manner; power saving by structures to adjust product structure to achieve energy-saving manner; power-saving technology is through the device update, the process of reform, to adopt advanced technology to achieve the section's way.

5. to promote energy-saving technology

To significantly improve energy levels, in addition to the optimized structure, strengthen management, we believe that promoting technological progress, promote energy-saving technology, updating and modification of old equipment, reconstruction of outdated technology, improve equipment efficiency, etc., are important. 1973 to 1985 period 19 major industrial countries have made significant energy saving achievement is mainly derived from technological progress, which is transformed with the production process and equipment technologies with low energy consumption, and successfully bring the country out of two energy crises. Recent national energy efficiency Conference focused on the promotion of energy saving technology, we should pay great attention to, try to use.

1, high efficiency and energy saving lamp

In recent years, China's energy-saving lamp is promoted by: rare-earth fluorescent, metal halide lamps, high pressure sodium lamp, dy light wire wire type of incandescent lamp. One of the rare-earth fluorescent lamp 11W light flux 60W incandescent equivalent, is the civil key promoting electric light sources. Roads, squares, factory, workshop, etc should promote the use of dysprosium lamps, high pressure sodium lamp, metal halide lamps.

2. power saving technology fans and pumps

We currently have various fan 700 million units, pump 3000 million units, the total output of about 1.1 million KW, annual electricity consumption in occupies national total consumption 1/3. Since the design performance and poor quality manufacturing, supporting unreasonable, operation and maintenance of a low level, the actual operation of fan efficiency ratio advanced countries low 5 ~ 20%. Estimated annual number of power 200 billion KWh.

3, electronic energy-saving technology

The electronic pressure regulator, speed technology enables the motor equipment and load the best fit, achieve economic operation, reducing power consumption. Microelectronics technology application microprocessor programming and process parameters and processes automated control.

4. cool energy-saving technology

It is night-time lows of refrigeration to electricity, the amount obtained by the cold store for daytime use of electricity, Gao-saving air conditioning electricity has great significance. Cool air conditioning system in the foreign application has more than 10 years, beginning in the 1990s a number of demonstration projects, energy-saving effects and economic benefits of the very significant.

5, waste heat recovery power generation technology

Cogeneration, TRT, waste heat recovery power, promoting for many years, our country has already achieved very good results, is also recyclable, pig iron, ferroalloys production process can generated, as well as recycling so gas fuel for power generation. In addition, trigeneration, power generation, and heating, and refrigeration, the efficiency of cogeneration.

6. transfer of peak power

Use load management technology, storage, storage technology, etc., repelling peak electricity to address power peak tension.

7, transformer power saving technology

National annual electric energy losses in transformers up to 300 billion KWh, promote the economic operation of transformers refers to the same delivery conditions, select a reasonable operating mode, improve operating conditions. Transformer technology refers to the old high loss transformers to adopt new technology, new material alteration of the purpose of achieving low loss. Low loss amorphous alloy transformer is in the early 1980s United States developed a new energy-saving transformer that can be promoted.

8. motor power saving technology

Our motor manufacturing relatively backward, not only its own performance indicators compared with developed countries, there is an obvious gap and motor capacity differential, private motor. Therefore, the motor and the production of mechanical properties do not match, the "big horse cart" widespread. Development of special energy-saving motor with great energy-saving potential.

9, electric furnace steel power-saving technology

At present, China's machinery industry electric power consumption per ton of steel than foreign advanced countries higher than 120 ~ 200KWh. Energy-saving measures are: the arc steel furnace short network into horizontal arm, you can make tons of steel power consumption reduce 5%; the use of microcomputer control SCR AC double winding motor power adjustment system, enables lower power consumption per ton of steel 15 ~ 20KWh; the use of additional charge, smelting, spectral analysis of oxygen and other technical measures can make tons of steel consumption dropped 50 ~ 100KWh, and can increase productivity, reduce the melting time.

10, electric heating energy-saving technology

Electric heating is mainly used in metal heattreatment and low-temperature baking. Many heating furnace Thermal performance design, thermal insulation insulation performance difference, the heating mechanism is somewhat reasonable, furnace body surface heat emission is great, the thermal efficiency is low. Heat treatment furnace uses the heat of polycrystalline mullite fiber, air insulation sandwich and durable fiber direct spray dressing fire new technologies, can economize on electricity by 40%; used for dewatering, drying, curing at low temperature electric heating furnace, promoting the use of high-strength infrared heating technology, transforming thermal design, selection of properties of insulation materials, etc., can economize on electricity by 50%.

VI. concluding remarks

Through the above on the significance of energy efficiency and technology exposition, fully recognizing that energy is related to the survival of all humanity, of events in a sustainable development strategy, so that every citizen and units must have energy saving consciousness, always to energy saving, energy-saving everything to.

My Government has attached great importance to energy-saving work, not only to the legal form of energy-saving behaviour of citizens of the specification, while promoting the use of energy-saving products and technology, our school is the local University, is the technical talent, set up energy-saving energy-saving technology service centre, you can play the role of the intermediate bridge helps government propaganda on energy saving consciousness, under the provision of technical services at the grass-roots level, to train large numbers of primary power workers to improve their level of energy-saving business, faster, and improve the region's energy-saving capability.