Некоммерческое акционерное oбщество
Алматинский университет энергетики и связи
Кафедра языковых знаний
профессионально-ориентированный английский (иностранный) язык
Методические указания для студентов специальности 5В071800 - Электроэнергетика
Алматы 2017
СОСТАВИТЕЛИ: С.А. Есенжолова, А.Т. Мурзатаева, Профессионально-ориентированный английский (иностранный) язык. Методические указания для студентов специальности 5В071800 - Электроэнергетика. - Алматы: АУЭС, 2017. - 35 с.
Данные методические указания предназначены для студентов специальности «Электроэнергетика». В методической разработке содержатся аутентичные тексты английской научно-технической литературы из разных источников. В конце каждого текста имеются задания лексического характера, которые студенты должны самостоятельно выполнить.
Методичесие указания рекомендуются к изданию.
Рецензент: к.ф.н. доцент Козлов B.C.
Печатается по плану издания некоммерческого акционерного общества «Алматинский университет энергетики и связи» на 2017 г.
© НАО «Алматинский университет энергетики и связи», 2017 г.
Введение
Методические указания разработаны на основе современных аутентичных и профессионально ориентированных материалов. Особое внимание уделяется технической лексике, терминам по электроэнергетике.
В методических указаниях приводятся упражнения на развитие таких видов речевой деятельности, как говорение, чтение и письмо. В упражнениях использованы слова для активного усвоения.
Данные учебно-методические указания могут быть использованы как при работе в аудитории, так и для дистанционного обучения, и индивидуальной работы.
Методические указания могут быть использованы на занятиях по профессиональному английскому языку на 3 курсе бакалавриата.
Power plants. Electric Power Plants
Electric Power Plants have a number of components in common and are an interesting study in the various forms and changes of energy necessary to produce electricity.
Boiler Unit.
Almost all of power plants operate by heating water in a boiler unit into super-heated steam at very high pressures. The source of heat from combustion reactions may vary in fossil fuel plants from the source of fuels such as coal, oil, or natural gas. Biomass or waste plant parts may also be used as a source of fuel. In some areas solid waste incinerators are also used as a source of heat. All of these sources of fuels result in varying amounts of air pollution, as well as, the carbon dioxide (a gas implicated in global warming problems).
In a nuclear power plant, the fission chain reaction of splitting nuclei provides the source of heat. Turbine-Generator: The super-heated steam is used to spin the blades of a turbine, which in turn is used in the generator to turn a coil of wires within circular arrangements of magnets. The rotating coil of wire in the magnets results in the generation of electricity.
Cooling Water.
After the steam travels through the turbine, it must be cooled and condensed back into liquid water to start the cycle over again. Cooling water can be obtained from a nearby river or lake. The water is returned to the body of water 10 -20 degrees higher in temperature than the intake water. Alternate method is to use a very tall cooling tower, where the evaporation of water falling through the tower provides the cooling effect.
Creating Electricity using a Generator.
If a magnetic field can create a current then we have a means of generating electricity. Experiments showed that a magnetic just sitting next to a wire produced no current flow through that wire. However, if the magnet is moving, a current is induced in the wire. The faster the magnet moves, the greater the induced current.
This is the principal behind simple electric generators in which a wire loop is rotated between to stationary magnetics. This produces a continuously varying voltage which in turn produces an alternating current.
Diagram of a simple electric generator is shown on the left. To generate electricity then, some (mechanical) mechanism is used to turn a crank that rotates a loop of wire between stationary magnets. The faster the crank turns the more current that is generated.
In hydroelectric, the falling water turns the turbine. The wind can also turn the turbine. In fossil fuel plants and nuclear plants, water is heated to steam which turns the turbine.
Wave Energy.
Wave energy is a renewable energy resource created by large storms hundreds of kilometers off-shore that generate and transmit huge amounts of energy that travels great distances (via swell) and mixes with local influences (seas) to arrive at our shores. It is a genuinely renewable energy source and distinct from tidal energy.
Wave energy is generally considered to be the most concentrated and least variable form of renewable energy. It is the high power density of wave energy that suggests it has the potential to become the lowest cost renewable energy source. If the potential of technologies like Poseidon is realized, the World Energy Council predicts that the total size of the exploitable resource could be 2000 TWh/year compared to world's total electricity consumption at around 16,000 TWh/year. Wave energy has a significant global potential. The most intense wave energy locations are found between 30° and 70° latitude in the northern and southern hemispheres. In Europe UK, Portugal, Spain, France and Norway in particular harbor excellent resource.
Unlike solar and wind, wave energy levels can be predicted many days in advance, making it less challenging to integrate wave energy into national power supplie grids.
Wind Energy.
Due to better wind conditions and reduced conflict potentials when applying for acreage, the wind industry is currently moving off-shore. Europe leads the world in the development of off-shore wind power, due to strong wind resources and shallow water in the North Sea, and limitations on suitable locations on land due to dense populations and existing developments. So far, all off-shore wind turbines have been installed with fixed foundation, restricting current wind farms to shallow waters. The huge wind power potential at deep waters is unexploited so far.
1. Translate the following words and word combinations from Russian into English.
1. Цепная реакция деления.
2. Перегретый пар.
3. Реакции горения.
4. Турбогенератор.
5. Ископаемое топливо.
6. Энергия волны.
7. Всемирный энергетический совет.
2. Translate the following words and word combinations from English into Russian.
1. Tidal energy.
2. Exploitable resource.
3. Supply grids.
4. High power density.
5. Stationary magnets.
6. Voltage.
7. Hydroelectric.
3. Match each item in column A with an appropriate item from column B and link the two in a sentence.
| A | B | |
| 1. | Marine | a) air-conditioning |
| 2. | Aeronautical | b) roads and bridges |
| 3. | heating and ventilating | c) body scanners |
| 4. | electricity generating | d) cables and switchgear |
| 5. | Automobile | e) communications and equipment |
| 6. | Civil | f) ships |
| 7. | electronic | g) planes |
| 8. | electrical installation | h) cars and trucks |
| 9. | medical | i) power stations |
| 4. | Study this list of points to consider when deciding whether to study |
| engineering. Tick [V] the statements which refer to you. Then ask your partner which statements refer to him or her. |
1. You enjoy practical projects -creating and investigating thing
2. You like finding out how things work.
3. You are interested in improving the environment.
4. You like helping people.
5. You enjoy solving problems.
6. You enjoy organizing activities.
7. You enjoy science programs on TV or on the radio.
8. You sometimes reed articles on scientific or engineering topics.
9. You have a lot of determination and stamina.
If you have ticked most of these statements, engineering is the right course of study for you.
Electrical power systems and networks
An electric power system is a network of electrical components used to supply, transmit and use electric power. An example of an electric power system is the network that supplies a region's homes and industry with power - for sizable regions, this power system is known as the grid and can be broadly divided into the generators that supply the power, the transmission system that carries the power from the generating centers to the load centers and the distribution system that feeds the power to nearby homes and industries. Smaller power systems are also found in industry, hospitals, commercial buildings and homes. The majority of these systems rely upon three-phase AC power - the standard for large-scale power transmission and distribution across the modern world. Specialized power systems that do not
always rely upon three-phase AC power are found in aircraft, electric rail systems, ocean liners and automobiles.
Basics of electric power.
An external AC to DC power adapter used for household appliances. Electric power is the product of two quantities: current and voltage. These two quantities can vary with respect to time (AC power) or can be kept at constant levels (DC power).
Most refrigerators, air conditioners, pumps and industrial machinery use AC power whereas most computers and digital equipment use DC power (the digital devices you plug into the mains typically have an internal or external power adapter to convert from AC to DC power). AC power has the advantage of being easy to transform between voltages and is able to be generated and utilized by brushless machinery. DC power remains the only practical choice in digital systems and can be more economical to transmit over long distances at very high voltages.
The ability to easily transform the voltage of AC power is important for two reasons: Firstly, power can be transmitted over long distances with less loss at higher voltages. So in power systems where generation is distant from the load, it is desirable to step-up (increase) the voltage of power at the generation point and then step-down (decrease) the voltage near the load. Secondly, it is often more economical to install turbines that produce higher voltages than would be used by most appliances, so the ability to easily transform voltages means this mismatch between voltages can be easily managed.
Solid state devices, which are products of the semiconductor revolution, make it possible to transform DC power to different voltages, build brushless DC machines and convert between AC and DC power. Nevertheless devices utilizing solid state technology are often more expensive than their traditional counterparts, so AC power remains in widespread use.
Balancing the grid.
One of the main difficulties in power systems is that the amount of active power consumed plus losses should always equal the active power produced. If more power would be produced than consumed the frequency would rise and vice versa. Even small deviations from the nominal frequency value would damage synchronous machines and other appliances. Making sure the frequency is constant is usually the task of a transmission system operator. In some countries (for example in the European Union) this is achieved through a balancing market using ancillary services.
Components of power systems: Supplies.
The majority of the world's power still comes from coal-fired power stations like this. All power systems have one or more sources of power. For some power systems, the source of power is external to the system but for others it is part of the system itself - it is these internal power sources that are discussed in the remainder of this section. Direct current power can be supplied by batteries, fuel cells or photovoltaic cells. Alternating current power is typically supplied by a rotor that spins in a magnetic field in a device known as a turbo generator. There have been a wide range of techniques used to spin a turbine's rotor, from steam heated using fossil fuel(including coal, gas and oil) or nuclear energy, falling water (hydroelectric power) and wind (wind power). The speed at which the rotor spins in combination with the number of generator poles determines the frequency of the alternating current produced by the generator. All generators on a single synchronous system, for example the national grid, rotate at sub-multiples of the same speed and so generate electrical current at the same frequency. If the load on the system increases, the generators will require more torque to spin at that speed and, in a typical power station, more steam must be supplied to the turbines driving them. Thus the steam used and the fuel expended are directly dependent on the quantity of electrical energy supplied. An exception exists for generators incorporating power electronics such as gearless wind turbines or linked to a grid through an asynchronous tie such as a HVDC link — these can operate at frequencies independent of the power system frequency. Depending on how the poles are fed, alternating current generators can produce a variable number of phases of power. A higher number of phases leads to more efficient power system operation but also increases the infrastructure requirements of the system.
Electricity grid systems connect multiple generators and loads operating at the same frequency and number of phases, the commonest being three-phase at 50 Hz or 60 Hz. However there are other considerations. These ranges from the obvious: How much power should the generator be able to supply? What is an acceptable length of time for starting the generator (some generators can take hours to start)? Is the availability of the power source acceptable (some renewables are only available when the sun is shining or the wind is blowing)? To the more technical: How should the generator start (some turbines act like a motor to bring themselves up to speed in which case they need an appropriate starting circuit)? What is the mechanical speed of operation for the turbine and consequently what are the numbers of poles required? What type of generator is suitable (synchronous or asynchronous) and what type of rotor (squirrel-cage rotor, wound rotor, salient pole rotor or cylindrical rotor)?
Making sure that the voltage, frequency and amount of power supplied to the loads are in line with expectations is one of the great challenges of power system engineering. However it is not the only challenge, in addition to the power used by a load to do useful work (termed real power) many alternating current devices also use an additional amount of power because they cause the alternating voltage and alternating current to become slightly out-of-sync (termed reactive power). The reactive power like the real power must balance (that is the reactive power produced on a system must equal the reactive power consumed) and can be supplied from the generators, however it is often more economical to supply such power from capacitors (see "Capacitors and reactors" below for more details).
A final consideration with loads is to do with power quality. In addition to sustained over voltages and under voltages (voltage regulation issues) as well as sustained deviations from the system frequency (frequency regulation issues), power system loads can be adversely affected by a range of temporal issues. These include voltage sags, dips and swells, transient over voltages, flicker, high frequency noise, phase imbalance and poor power factor. Power quality issues occur when the power supply to a load deviates from the ideal: For an AC supply, the ideal is the current and voltage in-sync fluctuating as a perfect sine wave at a prescribed frequency with the voltage at a prescribed amplitude. For DC supply, the ideal is the voltage not varying from a prescribed level. Power quality issues can be especially important when it comes to specialist industrial machinery or hospital equipment.
1. Translate the following words and word combinations from Russian into English.
1. Трехфазная сеть переменного тока.
2. Система снабжения электроэнергией.
3. Адаптер питания постоянного тока.
4. Цифровая система.
5. Бесщеточная техника.
6. Традиционные аналоги.
7. Балансировка сетки.
8. Топливные элементы.
9. Фотоэлементы.
2. Translate the following words and word combinations from English into Russian.
1. Magnetic field in a device.
2. Turbo generator.
3. Turbine's rotor.
4. Wind power.
5. Hydroelectric power.
6. Sub-multiples.
7. Renewables.
8. Synchronous or asynchronous.
9. Squirrel-cage rotor.
10. Wound rotor.
11. Cylindrical rotor.
3. Choose the correct information in columns B and C to describe the materials in column A.
A B C
1. An alloy allows heat or current to
flow easily
2. A thermoplastic temperatures
3. Mild steel current to flow easily
4. A conductor to 1.4% carbon
5 An insulator heated
6 High carbon steel 5% to 0.3% carbon
7 Brass metals or elements
8 A thermosetting plastic
| remains rigid at high does not allow heat or |
| a metal |
| contains iron and 0.7% |
| a material |
| becomes plastic when |
| an alloy |
| contains iron and 0.1 formed by mixing other consists of copper and |
zinc.
4. Explain each of these methods of connection.
1. Screwed
2. Soldered
3. Attached
4. Wired
5. Bonded
6. Glued
7. Riveted
8. Welded
9. Brazed
10. Nailed
Electric-power supply
Electric power supply system in a country comprises of generating units that produce electricity; high voltage transmission lines that transport electricity over long distances; distribution lines that deliver the electricity to consumers; substations that connect the pieces to each other; and energy control centers to coordinate the operation of the components. Power supplies can be integrated into a device or externally attached, portable modules, depending on their operating temperature and risk of overheating. Power supplies are necessary to the operation of just about every electrical device, including desktop and laptop computers, cell phones, lasers, telecommunications like radio, phone lines and the internet, medical equipment, lamps, appliances and industrial machinery. They provide either AC power supply, which is an alternating current, or DC power supplies, which offer a direct current. Today, most electronic devices in the home and office are powered by 12V power supply, while industrial applications employ high voltage power supply. Different devices and electronics require certain types of current, frequency
and voltage. In these cases, AC to DC converters are used to switch the type of current, which are also called power inverters. They use rectifier, which contain diodes that alter and regulate the electrical current. Frequency converters and switching power supplies are integrated into the power supply unit in order to give off the appropriate output. Some variable power Supplies are able to adjust the output voltage to specific requirements for product testing and design. Most electronic products today require regulated power supply, a type that produces stable and constant output at a certain, unwavering voltage regardless of power outages, brown outs or surges. Most power supplies are protected by a backup battery. These are called uninterruptible power supplies, and are reliable even when there is no power available.
There are two main types of electrical current that are regulated, controlled and altered by power supplies-alternating current and direct current. Both are used to power different kinds of electrical products, but the input into a power supply from a battery or other power source is almost always AC. Alternating current exhibits electrical charge that consistently and periodically reverses direction. It moves forward then backwards over and over. This form of current is used in commercial businesses and residential buildings. The alteration of the current's direction is measured in Hertz. For example, 60 Hertz refers to the number of alternative directions the current takes in a second. Direct current, on the other hand, refers to electric charge flow that runs in a single, linear direction. It flows in metal conductors like wires, semiconductors, insulators or even a vacuum. Cell phones and laptop computers use DC, as well as medical equipment, video technology and process control systems. Direct current units are usually external from the electronic device and held within a protective casing.
Power supply manufacturers offer many different designs and configurations of power supply units, which range depending on their application, type of current, frequency and voltage level. Some of the unit designs and styles are external, meaning they are separate components to the electronic device. These include board, cabinet, desktop, module, open frame, enclosed, rack mount and wall mount. If their operating temperature is low enough, many power supply units are integral parts of the device, located inside them. Some of the display choices available, which provide information about the voltage and current that are the result of measuring and monitoring, are digital numerical displays, analog visual indicators and graphic or video displays. Some of the various features include adjustable voltage, which can be increased or decreased by a dial or knob, adjustable frequency, computer interface, fan cooling systems, as well as integral heatsink and overcurrent protection. Many also work in conjunction with a backup battery that is employed in case of a power outage. Other features include overvoltage protection, power factor correction, and pure sine output, remote on and off switch, short circuit protection and water cooling. When looking at power supply units, consider some of these specifications: the number of outputs, DC output voltage, DC output power, AC output voltage, AC output frequency, operating temperature and apparent power.
One of the most common applications for power supply manufacturers is electrical power for computers. This vital component is a smaller, black metal box typically located on the back of the computer in a corner of the case. The power supply unit also contains the power-cord receptacle and the cooling fan and is usually visible from the back of a system. Power supply units use switcher technology to convert AC input to lower DC voltages, so they are commonly referred to as switching power supplies. The voltages commonly supplied are 3.3 volts and 5 volts, which are used by digital circuits, and 12 volts, which run motors in disk drives and fans. In order for the power button to work when the PC is off, the power supplies have a circuit that supplies 5 volts, called "standby voltage" or VSB.
There are three types of uninterruptible power supplies (UPS). An offline UPS is basically a standby system that provides battery power to equipment when the main power supplies fall below a set limit. These power supplies do not cost much and are recommended for home office use. A line interactive UPS is similar to an offline UPS in that it switches to battery mode during a blackout. However, this UPS actually boosts the main power supply when it falls, using a regulator. These power supplies are ideal for business applications. The highest level of protection for an electrical device is an online UPS unit that converts AC to DC and then back to AC to supply critical power loads. These UPS units, often referred to as double conversions, contain an automatic bypass to ensure continuous power supplies during a short-term overload or UPS failure. On-line UPS systems are perfect for critical loads and sensitive equipment, such as medical technology.
1. Translate the following words and word combinations from Russian into English.
1. Электрическая система питания.
2. Энергоблоки.
3. Линии электропередачи.
4. Электропитание.
5. Портативные модули.
6. Настольные и портативные компьютеры.
7. Телекоммуникаций.
8. Источник питания переменного тока.
9. Постоянный ток.
10. Выходное напряжение.
11. Резервный аккумулятор.
2. Translate the following words and word combinations from English into Russian.
1. Uninterruptible power supplies.
2. Electric charge.
3. Direct current.
4. Protective casing.
5. Digital numerical displays.
6. Analog visual indicators.
7. Adjustable frequency.
8. Integral heatsink.
9. Back up battery.
10. Water cooling.
11. Metal box.
12. Switching power supplies.
3. The technical words in column A are similar in meaning to the more general English in column B. Match them.
| A | B | |
| 1. | Oscillates | a) changes |
| 2. | Rotates | b) large, thin, flat pieces |
| 3. | Reciprocates | c) moving stairs |
| 4. | Has a linear motion | d) goes round and round |
| 5. | Converts | e) movement |
| 6. | Motion | f) goes in a Line |
| 7. | Escalator | g) swings backwards and forwards |
| 8. | Sheets | h) goes up and down. |
| 4. | Find out what these terms mean | in education. Use a dictionary if necessary. |
| 1. | Pass. 2. Resit. 3. Assessment. 4. | Fail. 5. Drop out. 6. Period. 7. Full-time. |
8. Module
What is relay? Definition of protective relay
A relay is automatic device which senses an abnormal condition of electrical circuit and closes its contacts. These contacts in turns close and complete the circuit breaker trip coil circuit hence make the circuit breaker tripped for disconnecting the faulty portion of the electrical circuit from rest of the healthy circuit.
Now let's have a discussion on some terms related to protective relay.
Pickup level of actuating signal: The value of actuating quantity (voltage or current) which is on threshold above which the relay initiates to be operated. If the value of actuating quantity is increased, the electromagnetic effect of the relay coil is increased and above a certain level of actuating quantity the moving mechanism of the relay just starts to move.
Reset level: The value of current or voltage below which a relay opens its contacts and comes in original position.
Operating Time of Relay - Just after exceeding pickup level of actuating quantity the moving mechanism (for example rotating disc) of relay starts moving and it ultimately close the relay contacts at the end of its journey. The time which elapses between the instant when actuating quantity exceeds the pickup value to the instant when the relay contacts close.
Reset time of Relay - The time which elapses between the instant when the actuating quantity becomes less than the reset value to the instant when the relay contacts returns to its normal position.
Reach of relay - A distance relay operates whenever the distance seen by the relay is less than the pre-specified impedance. The actuating impedance in the relay is the function of distance in a distance protection relay. This impedance or corresponding distance is called reach of the relay.
Power system protection relays can be categorized into different Types of relays.
Types of Relays.
Types of protection relays are mainly based on their characteristic, logic, on actuating parameter and operation mechanism.
Based on operation mechanism protection relay can be categorized as Electro Magnetic relay, Static relay and Mechanical relay. Actually relay is nothing but a combination of one or more open or closed contacts. These all or some specific contacts the relay change their state when actuating parameters are applied to the relay. That means open contacts become closed and closed contacts become open. In electromagnetic relay these closing and opening of relay contacts are done by electromagnetic action of a solenoid.
In mechanical relay these closing and opening of relay contacts are done by mechanical displacement of different gear level system.
In static relay it is mainly done by semiconductor switches like thyristor. In digital relay on and off state can be referred as 1 and 0 state.
Based on Characteristic the protection relay can be categorized as
- definite time relays;
- inverse time relays with definite minimum time (idmt);
- instantaneous relays;
- idmt with inst;
- stepped characteristic;
- programmed switches;
- voltage restraint over current relay.
1. Translate the following words and word combinations from Russian into English.
1. Oпределение защитного реле.
2. Электрические цепи.
3. Автоматический предохранитель.
4. Электромагнитное воздействие.
5. Система питания.
6. Операционный механизм.
7. Электромагнитное реле.
8. Статическое реле.
2. Translate the following words and word combinations from English into Russian.
1. Mechanical relay.
2. Instantaneous relays.
3. Closed contacts.
4. Specific contacts.
5. Electromagnetic relay.
6. Semiconductor switches.
7. Voltage restraint over current relay.
8. Programmed switches.
9. Stepped characteristic.
| Function |
| 1. Armature 2. Bearings 3. brushes 4. Commutator 5. Drive shaft 6. Field windings |
3. Match each of these motor components to its function, and then describe its function in a sentence.
Component
a) transfers rotation from the motor
b) create an electromagnetic field
c) converts electromagnetic energy to rotation
d) reverses the current to the armature
e) support the drive shaft
f) supply current to the armature
4. Study the safety instructions from a workshop below, and then answer these questions.
a) Who are the instructions for?
b) Who wrote them?
c) What was the writer's purpose?
1. Wear protective clothing at all times.
2. Always wear eye protection when operating lathes, cutters, and grinders and ensure the guard is in place.
3. Keep your workplace tidy.
4. The areas between benches and around machines must be kept clear.
5. Tools should be put away when not in use and any breakages and losses reported
6. Machines should be cleaned after use.
Generators
The dynamo invented by Faraday in 1831 is certainly a primitive apparatus compared with the powerful, highly efficient generators and alternators that are in use today» Nevertheless, these machines operate on the same principle as the one invented by the great English scientist. When asked what use his new invention had, Faraday asked in his turn: "What is the use of anew-born child?" As a matter of fact, "the new-born child" soon became an irreplaceable device we cannot do without.
Although used to operate certain devices requiring small currents for their operation, batteries and cells are unlikely to supply light, heat and power on a large scale. Indeed, we need electricity to light up millions of lamps, to run trains, to lift things, and to drive the machines. Batteries could not supply electricity enough to do all this work.
That dynamo-electric machines are used for this purpose is a well-known fact. These are the machines by means of which mechanical energy is turned directly into electrical energy with a loss of only a few per cent. It is calculated that they produce more than 99.99 per cent of all the world's electric power.
There are two types of dynamos, namely, the generator and the alternator. The former supplies direct current which is similar to the current from a battery and the latter, as its name implies provides alternative current.
To generate electricity both of them must be continuously provided with energy from some outside source of mechanical energy such as steam engines, steam turbines or water turbines, for example.
Both generators and alternators consist of the following principal parts: an armature and an electromagnet. The electromagnet of a direct current generator is usually called a stator for it is in a static condition while the armature (the rotor) is rotating.
Alternators may be divided into two types:
- alternators that have a stationary armature and a rotating electromagnet;
- alternators whose armature serves as a rotor but this is seldom done. In order to get a strong e.m.f., the rotors in large machines rotate at a speed of thousands of revolutions per minute (r.p.m.). The faster they rotate, the greater the output voltage the machine will produce.
1. Translate the following words and word combinations from Russian into English.
1. Аппарат.
2. Изобретение.
3. Токи.
4. Аккумуляторы.
5. Тепло.
6. Мощность.
7. Электродинамические машины.
8. Энергия.
2. Translate the following words and word combinations from English into Russian.
1. Electrical energy.
2. Electric power.
3. Generator.
4. Alternator.
5. Armature.
6. Electromagnetic voltage.
7. Engine.
3. Study the company document on safety on the next page, and then answer these questions.
1. Who is this document for?
a) machine operatives
b) managers
c) all employees
d) injured employees
2. Who wrote this document?
a) trade union representative
b) technician
c) manager
d) medical staff
3. What is the writer's intention?
a) to prevent accidents
b) to ensure speedy help for injured employees
c) tn protect the company
d) to warn about dangers
Accident investigation
Whenever an accident occurs that result in an injury (medical case), damage of equipment and material, or both, prompt accident investigation by the immediate manager is required. A written preliminary investigation will be completed by the end of the particular shift or business day on which the accident occurred. In no event should there be a delay of more than 24 hours. Failure to comply with this requirement may subject the immediate manager to disciplinary action up to and including discharge. Without adequate accident investigation data the Company may be subjected to costs, claims, and legal action for which it has no defence. As a minimum, the preliminary accident investigation report will include the following:
1. Name, occupation, and sex of injured worker.
2. Place and date/ time of accident.
3. Description of how the accident happened.
4. Immediate causes of the accident -unsafe acts and unsafe conditions.
5. Contributing causes - manager safety performance, level of worker baking, inadequate job procedure, poor protective maintenance, etc.
6. Witness (es) - name and department.
7. Corrective action taken- when.
The employee who was injured and any employee(s) who witnessed the incident should be separately interviewed as soon as possible. A copy of the report must be submitted to the Manager - Human Resources for review. Another copy of the report is to be retained for a period of not less than the injured employee's length of employment plus five (5) years.________________
Transmission of three-phase power
The three windings discussed above can be made to supply three individual circuits, when all six ends must be used. It is possible, however, to link the three circuits electrically with the result that the number of conductors necessary for the transmission of the power is reduced.
In the first instance it is possible to affect an economy by using a common return, this being permissible since it does not disturb the electrical arrangement. This implies that the three rear ends of the turns, A', B', and С' must all be joined, together with the three rear ends of the three resistances used as loads. This arrangement is illustrated in Fig. 7 which shows the three generator windings connected together at one end, the other ends being connected to three conductors for the purpose of transmitting the power. The return conductor carries the vector sum of these three currents back to the common junction of the three generator windings.
If the three e. m. f. s are all equal and the three load resistances are also all equal, the three currents will also be all equal and will have a phase difference of 120° from one another. In these circumstances the system is said to be balanced.
Three-Wire Transmission. In a balanced three-phase system the three currents are equal and can be represented by the graphs shown in Fig. 6, substituting current for e. m. f.
Generator Three*Phase Load
Fig.6. Three-Phase E. M. F.'s or Currents. Fig. 9. Connections for Three-
Phase Four-wire System
|
The resultant current in the fourth (return) conductor is, at any instant, the algebraic sum of the three line currents and, on examination of the graphs, it is found that this algebraic sum is zero at every instant. The fourth (return) conductor thus carries no current and it can be omitted. The connections now take the form shown in Fig. 8, three conductors only being employed. Each conductor now acts in turn as the return for the other two. This can be checked from Fig. 6, where it is seen that the reverse current in one phase is always equal to the forward current in the other two.
Three-Phase Four-Wire System. This is a system of connections which permitsthe employment of a three-phase load and three single-phase loads simultaneously, as shown in Fig. 9. It re-introduces the fourth conductor to act as a common return for the three singlephase loads, this conductor being called the neutral. The other three conductors are called the line conductors. The system is earthed as before, by connecting the neutral conductor to an earthed plate or other earthing connection.
Colour Scheme. For purposes of standardization it is now the general practice to mark each particular phase by a distinctive colour. The three phases are coloured red, white (or yellow), and blue, respectively, while the neutral conductor is coloured green.
Fig. 7. Transmission of Three-Phase Power by Four Conductors
|
| Fig. 8. Transmission of Three- Phase Power by Three Conductors |
1. Translate the following words and word combinations from Russian into English.
1. Цепь.
2. Проводник.
3. Электричество.
4. Расположение.
5. Сопротивление.
2. Translate the following words and word combinations from English into Russian.
1. Three-Wire Transmission.
2. Current.
3. Three-Phase Four-Wire System.
4. Single-phase load.
5. Colour scheme.
3. Complete these sentences using Unless and your knowledge of engineering.
Unless the ignition is switched on, a car cannot_____________.
Unless the pilot light is on, gas central heating wills not____________.
Unless the diverter valve is switched to central heating, the radiators will not.
Unless there is current flowing in the primary coil of a transformer, there
will
be no current in the____________ coil.
Unless there is______________ in the cylinders, a petrol engine will not
start.
Unless the doors are_____________, a lift will not operate.
Unless mild steel is painted, it will_____________.
Unless electrical equipment is earthed, it may be_____________.
4. What new relationships can you find in the examples below? Rewrite each compound to show the relationship. For example:
- a foot pump a pump which is operated by foot;
- a ribbon cable a cable which is like a ribbon;
- a gear lever a lever for operating gears.
| 1. | chain wheel | 6. college lecturer |
| 2. | disc wheel | 7. toe-clip |
| 3. | foot brake | 8. boiler thermostat |
| 4. | a hand throttle | 9. safety helmet |
| 5. | strain gauge | 10. aircraft engineer |
Non-traditional renewable sources of energy
It is known that much is being done in the world today for the development of non-traditional sources of energy. Without them the Earth cannot support its present population of 5 billion people and probably 8 billion people in the 21st century.
Now we are using traditional powerhouses, that is, oil, natural gas, and coal and water power with the consumption of more than 50 billion barrels per year. It is evident that these sources are not unlimited.
That is why it is so important to use such renewable sources of energy as the sun, wind, geothermal energy and others. Research is being carried out in these fields.
One of the most promising (перспективный) research is the development of power stations with direct transformation of solar energy into electricity on the basis of photo-effect. It was Russia that was the first in the world to develop and test a photoelectric battery of 32,000-volts and effective area of only 0.5 sq. m., which made it possible to concentrate solar radiation. This idea is now being intensively developed in many countries.
However, the efficiency of a solar power station is considerably reduced because of the limited time of its work during the year. But it is possible to improve the efficiency of solar power stations by developing different combinations of solar power stations and traditional ones - thermal, atomic and hydraulic. Today some engineers are working at the problem of developing electric power stations with the use of a thermal-chemical cycle. It will operate on products of the transformation of solar energy, whereas me «solar» chemical reactor uses CO2 and water steam of the thermal power station. The result is that we have a closed cycle.
It is planned that plants working on the energy of the solar heat provided by the sun will be built on a larger scale. That different wind energy plants are being developed is also well-known. These energy plants can be small (of several kilowatts) and large powerful systems. It is important that all these advances in developing new sources of energy and improving the old ones help to solve the energy problem as a whole and they do not have negative effects on the environment.
1. Translate the following words and word combinations from Russian into English.
1. Нефть.
2. Природный газ.
3. Уголь.
4. Энергия.
5. Геотермальная энергия.
6. Электростанция.
7. Фотоэффект.
2. Translate the following words and word combinations from English into Russian.
1. Photoelectric.
2. Battery.
3. Volts.
4. Effective.
5. Atomic.
6. Hydraulic.
7. Engineer.
3. Complete these sentences from technical conversations using the words in the box. Look at A opposite to help you.
| budget | cost-effective | exceed | feature proposed |
| constraint | designed | existing | function |
| 1. Of course, money is limited. Cost imitations are always a__________. But some finance is available. A____________ has been allocated for the preliminary design phase - a total of $ 33,000. But we mustn't that amount. |
2. Obviously, if we have to spend?70, that's not a_________ design solution.
3. The __________ of this detector is to locate underground cables by giving
audio feedback. Since it's _____________ to be used in noisy environments, the
earphone is an important___________.
4. Are these already on the market - are they_____________ products? Or are
we talking about ___________ products that are still under development?
4. Choose the correct words from the brackets to complete the sentences. Look at B opposite to help you.
1. The types of loads that will be encountered must be (designed / determined).
2. Maximum loads are based on predicted (specifications / worst-case scenarios).
3. On top of maximum loads, additional safety margins are (factored in /
sized).
4. For cost reasons, components shouldn't (overdesigned / quantified).
5. The practice of overdesigning components can be described as the (belt and braces / factor of safety) approach.
6. (Quantifying / Sizing) components means calculating their dimensions.
Solar Energy
What is solar energy? Solar energy is the radiant energy produced by the Sun. It is both light and heat. It is along with secondary solar-powered resources such as wind and wave power, account for the majority of the renewable energy on Earth. The Earth receives 174 pet watts (PW) of solar radiation at the upper atmosphere. 30% of that is reflected back to space and the rest is absorbed by clouds, oceans and land masses. Land surfaces, oceans, and atmosphere absorb solar radiation, which increases their temperature. Warm air containing evaporated water from the oceans rises, causing convection. When the air reaches a high altitude, where the temperature is low and water vapor condenses into clouds and causes rain. The latent heat of water condensation increases convection, producing wind. Energy
absorbed by the oceans and land masses keeps the surface at an average temperature of 14°C. Green plants convert solar energy into chemical energy through photosynthesis. Our food supply is completely dependent on solar energy. After plants die, they decay in the Earth, so solar energy can be said to provide the biomass that has created the fossil fuels that we are dependent on.
Humans harness solar energy in many different ways: space heating and cooling, the production of potable water by distillation, disinfection, lighting, hot water, and cooking. The applications for solar energy are only limited by human ingenuity. Solar technologies are characterized as either passive or active depending on the way the energy is captured, converted, and distributed. Active solar techniques use photovoltaic panels and solar thermal collectors to harness the energy. Passive techniques include orienting a building to the Sun, selecting materials with thermal mass properties, and using materials with light dispersing properties.
Our current dependence on fossil fuels is slowly being replaced by alternative energies. Some are fuels that may eventually become useless, but solar energy will never be obsolete, controlled by foreign powers, or run out. Even when the Sun uses up its hydrogen, it will produce useable energy until it explodes. The challenge facing humans is to capture that energy instead of taking the easiest way out by using fossil fuels.
1. Translate the following words and word combinations from Russian into English.
1. Энергия волны.
2. Солнечная радиация.
3. Верхние слои атмосферы.
4. Космос.
5. Температура.
6. Теплый воздух.
7. Дистилляция.
2. Translate the following words and word combinations from English into Russian.
1. Disinfection.
2. Technologies.
3. Photo voltaic panels.
4. Collectors.
5. Dispersing.
6. Alternative energies.
7. Using fossil fuels.
3. Fill in the blanks in these sentences with either up or down.
| 1. As the car slows |
, kinetic energy is converted to heat.
| cables and switchgear. |
| and |
2. An installation technician connects
3. A plastic pellet in a washing machine door heats
pushes the lock into position.
| the brake discs. |
| the into three |
4. Car wheels are ventilated to cool
5. Transformers are used on construction sites to step mains voltage to avoid accidents with hand tools.
6. Students in David's maths class were split_________
groups.
7. One of Lucy's friends came
8. Students should keep____ with the name Swing ex-L.
with subjects lie maths and physics.
4. Explain the function of these objects:
1. Shock absorber
2. Signal generator
3. Speed governor
4. Battery charger
5. Pressure regulator
6. Circuit breaker
7. Hardness tester
8. Fuse holder
9. Engine immobilizer
10. Temperature sensor
Natural Resources and Energy
Natural resources occur naturally within environments that exist relatively undisturbed by humanity, in a natural form. A natural resource is often characterized by amounts of biodiversity and geodiversity existent in various ecosystems. Natural resources are derived from the environment. Some of them are essential for our survival while most are used for satisfying our wants. Natural resources may be further classified in different ways.
Natural resources are materials and components (something that can be used) that can be found within the environment. Every man-made product is composed of natural resources (at its fundamental level). A natural resource may exist as a separate entity such as fresh water, and air, as well as a living organism such as a fish, or it may exist in an alternate form which must be processed to obtain the resource such as metal ores, oil, and most forms of energy.
There is much debate worldwide over natural resource allocations; this is partly due to increasing scarcity (depletion of resources) but also because the exportation of natural resources is the basis for many economies.
Some natural resources such as sunlight and air can be found everywhere, and are known as ubiquitous resources. However, most resources only occur in small sporadic areas, and are referred to as localized resources. There are very few resources that are considered inexhaustible (will not run out in foreseeable future) - these are solar radiation, geothermal energy, and air (though access to clean air may not be). The vast majority of resources are exhaustible, which means they have a finite quantity, and can be depleted if managed improperly.
What is always present but never visible? ENERGY! Energy is a difficult concept to understand because it is not a concrete object that you can see or touch. To understand what energy is, you must first understand what it does. That is, although energy isn't visible, you can detect evidence of energy. Jumping, moving a wheelchair, eating, and singing all require energy. Nonliving things also use energy—a clock, vacuum cleaner, and mechanical toys all require energy to move. Work is involved whenever anything moves a distance, and energy is needed to do work. Therefore, energy is defined as the ability to do work.
Much like mass or volume, energy is a property of an object. It's just that energy is more abstract than some other properties. Although energy itself isn't visible, you can detect evidence of energy.
Movement, sound, heat, and light provide evidence that energy is present and being used. Sound is produced when we strike something. But does sound do work? Yes, sound can move things. Sound waves move the tiny bones in your ears and shake windows when a loud truck passes by. Sound waves are also evident in the vibrations from playing a radio.
Our body is working even when it appears to be still. Breathing, blinking, and digesting food all require energy. For us to do these activities, our bodies burn the energy in food. We know this is happening because we feel warm (burning generates thermal energy, or heat). Therefore, heat is evidence that energy is being used. If energy is the ability to do work, how does thermal energy fit into this definition? Thermal energy can melt an ice cube or make water boil. Therefore, the definition of energy can be amended to energy is the ability to do work or to organize or change matter.
Light is another observable form of energy. Light can change things. When light shines on your arm, it makes it feel warm. When light shines on a green plant, the plant can make food.
Since energy is a property of matter, scientists have discovered ways to measure and quantify energy. Measuring energy helps to understand how it is used, how it changes forms, and how to increase energy efficiency.
1. Translate the following words and word combinations from Russian into English.
Природные ресурсы.
Биоразнообразия.
Экосистема.
Материалы и компоненты.
Юридический.
Живой организм.
Альтернативный.
2. Translate the following words and word combinations from English into Russian.
1. May exist in.
2. Exportation.
3. Non living things.
4. Sound waves move.
5. Vibration.
6. Quantify.
7. Energy efficiency.
3. Fill in the blanks in these sentences with either on or of. You have studied these verbs in similar contexts.
1. Failure means that expensive development costs must be written with no result.
2. The alarm goes_____________ if a window is broken.
3. When the water is hot, the control unit moves__________ to the next stage
of the washing programme.
4. Components which rely____________ metal upon metal contact require
lubrication.
5. A thermostat causes the gas control valve to shut____________ when the
room temperature is correct.
6. Feedback is used to check_________ water level, temperature, and drum
speeds.
7. A car thief would set____________ the alarm.
8. If a system is needed urgently, there is no question of knocking at the usual time.
9. Power may come from a small turbine engine, running______________ a
clean fuel like natural gas.
10. The accident occurred after the plane took____________.
4. Study these lists. A and B. Items in list A are causes of those in list B but the items are mixed up. Link the related items. For example:
reduction in cross-section loss of strength
A B
- reduction in cross-section a) corrosion
- insulation breakdown b) bearing failure
- overtightening
- overloading a circuit
- carelessness
- impurities
- lack of lubrication
- friction
- repeated bending
| c) excessive heat d) shearing in metal e) loss of strength f) shearing in bolts g) blown fuses h) short circuits i) accidents j) wear and tear in |
- overrunning an electric motor
machinery
Now write sentences to show the link. For example: Loss of strength results from reduction in cross-section.
World Energy Resources
The World Energy Council, in the interest of ensuring a sustainable energy future for all, has been conducting the World Energy Resources study (former Survey of Energy Resources) since 1933. The World Energy Resources report covers 12 major fossil fuel and renewable sources, with national assessment for all of the WEC's member countries. For over 80 years this highly regarded publication has been a reference tool for governments, industry, investors, IGOs, NGOs and academia.
This statistical report presents values for reserves and production of various resources at the global level. The World Energy Resources project team and its working groups collect and analysis data on specific resources and reserves. In addition to resource data the report also assesses current and emerging technologies, to provide a solid basis for energy policy and decision-making.
"The WEC is the only global organization that gathers such a wide range of data covering finite resources, such as coal and gas, as well as nuclear and renewable sources, including geothermal, hydro and wind energy".
The report aims to provide a comprehensive knowledge foundation for all policy and strategic decisions, including the answers to some of the energy sector's most pressing questions:
1) When will the world run out of oil?
2) What is the status and potential benefit of shale gas, biomass, wind, solar and other renewable and fossil energy resources?
3) What are the issues impacting smart grids, energy-water linkages, carbon capture and sequestration, clean coal technologies, fourth-generation nuclear, or e- mobility?
4) What is the energy return on energy invested?
The World Energy Resources study group engages leading experts in reviewing resource data and other information and collects data from industry, government and academia across all regions. Individual members of the study group meet regularly to discuss trends in energy resource exploration and development.
Energy Resources.
Along with all other natural resources like air, water, land, forest