Урок 2.7

Текст А

Solar collector orientation (part I)

Even though solar collectors can collect heat from the diffuse component of solar radiation, solar systems are designed to use the direct component. Direct radiation is in the form of parallel rays coming straight from the sun. To best capture this energy the solar collector should be tilted so that it is more nearly perpendicular to the solar rays. The "optimum" tilt angle varies as the sun changes its position throughout the day and year. However, since the solar system cannot be continuously moved, some general rules can be stated: a) for all year domestic hot water (DHW) heating engineers use a tilt angle equal to the latitude; b) for all year DHW heating and winter space heating engineers use a tilt angle equal to the latitude plus 10-15 degrees; c) for all year DHW heating, winter space heating and summer cooling they use same as (a); d) for winter only space heating they use a tilt angle equal to the latitude plus 10-15 degrees; e) for summer space cooling they use a tilt angle equal to the latitude minus 10-15 degrees; f) for summer only space cooling and all year DHW heating they use the same as (e). In addition to choose the best collector tilt angle, consideration must be given to the orientation of a collector (i.e. the direction the collector faces). Normally true south is the best and most frequent choice. However, slightly west of south (10 degrees) may be preferable in some locations if an early morning haze or fog is a regular occurrence.

Notes:

tilt angle угол наклона

true south географический юг

Ответьте на вопросы к тексту:

1. What is the direct radiation?

2. Why should the solar collector be tilted so that it is more nearly perpendicular to the solar rays?

3. How does the "optimum" tilt angle vary?

4. What rule can be stated for summer space cooling?

Упражнение № 1. Переведите слова и словосочетания на русский язык.

Solar collector; diffuse component; solar radiation; direct component; direct radiation; parallel ray; solar ray; tilt angle; domestic (adj.); equal (adj.); space heating; degree (n.); space cooling; consideration (n.); orientation (n.); direction (n.); slightly (adv.); early morning haze.

If; even though; throughout; however; since.

Упражнение № 2. Переведите слова и словосочетания на английский язык.

Наклоняться; удерживать; угол наклона; равный; явление; сухой (легкий) туман; густой туман; постоянная составляющая; прямое излучение; направленное излучение; отопление помещений; охлаждение помещений.

Упражнение № 3. Сопоставьте слово А с его определением В.

А

1. ray;

2. angle;

3. radiation;

4. domestic;

5. latitude.

В

1. the distance north or south of the equator;

2. used in people's homes;

3. energy in the form of heat or light that is sent out as waves that you cannot see;

4. the space between two straight lines or surfaces that join each other, measured in degrees;

5. a straight narrow beam of light from the sun or moon.

Упражнение № 4. Переведите следующие предложения, определите функцию герундия.

1. In addition to choosing the best collector tilt angle, consideration must be given to the orientation of a collector.

2. Boiler is a container for boiling water that is part of a steam engine, or is used to provide heating in a house.

3. Drum is a large round container for storing liquids such as oil, chemicals etc.

4. The costs for cleaning the pipes and the walls are around 3500 euros a year.

5. The atmosphere reduces the radiation and is also responsible for scattering of light.

6. A heat exchanger that suffers from fouling needs additional energy to keep operating at the same level.

7. Some of these processes are required additional help by pumping the single phase flow.

8. By reversing the flow direction, the brush will then be taken to the other side again.

9. By controlling the mixing process in the right way the combustion can be made more uniform.

Упражнение № 5. Переведите следующие предложения. Определите время и залог сказуемых.

1. Direct radiation is in the form of parallel rays coming straight from the sun.

2. Solar collectors can collect heat from the diffuse component of solar radiation.

3. The amount of solar energy received at any location depends on the hour of the day, the day of the solar year, and the meteorological conditions.

4. Boilers are used in large industrial plants to create steam.

5. All kinds of online cleaning methods were developed.

6. The governments of different countries in the European Community have made programs for reducing the amount of NOx and SO emissioned.

7. Heat transferred from the warmer fluid to the colder fluid encounters resistances that will create several losses.

8. This advice will have suffered less thermal forces by the end of the month.

9. We could have discussed the question but we didn’t have enough time.

10. The clear liquid doesn’t have colour and smell.

Упражнение № 6. Переведите следующие предложения, определите функцию инфинитива.

1. Solar systems are designed to use the direct component.

2. To best capture this energy the solar collector should be tilted so that it is more nearly perpendicular to the solar rays.

3. To reach these requirements a number of measures were taken by the government.

4. Since the solar system cannot be continuously moved, some general rules are stated.

5. To choose the best collector tilt angle, consideration must be given to the orientation of a collector.

6. We must examine equations to understand what factors influence the dimensions of this heat exchanger when a certain heat rate is expected.

7. Frequently it is necessary to get an idea of how big a heat exchanger will be for a certain performance.

8. A pumping device is needed to maintain high pressure drop.

9. The ratio of capacitances is needed to retrieve the effectiveness

Упражнение № 7. Задайте пять разделительных и пять альтернативных вопросов к тексту.

Solar collector orientation (part II)

Текст В

Some deviations from the tilts and orientation angles are allowable without significantly affecting performance. As shown in the figure 2.3 and 2.4 the tilt angle may vary +/- 10 degrees and the orientation angle up to 20 degrees either side of true south. For these deviations the solar collectors would still collect 95%-100% of their rated capacity in most locations of the U.S. Additional deviations would require more collector area to capture the same amount of energy. For each deviation of 10 degrees beyond engineers should add 10% more collector area. If they must choose between an east roof and a west roof, they use the west roof in the western coastal area. Other areas will require local weather considerations.

As important as collector location is keeping the collectors out of the shade, especially between 9 a.m. and 3 p.m., when most of the useful energy collection occurs. The designer should try to anticipate any future structures or vegetation (trees) that could block future solar access. In summary, although many buildings will not have a "perfect" solar orientation, there can still be many places with good solar energy potential.

Advantages and disadvantages. Solar energy is inherently nonpolluting, provides substantial freedom from the effects of fuel price increases and saves valuable fossil fuels. Disadvantages are that collectors perform poorly in cold cloudy weather, when most needed; and room heat exchangers and industrial unit heaters must be larger than in conventional systems due to the relatively low temperature of heating fluid. The disadvantages may be circumvented by good design; where fuel costs are high enough, a solar system will prove cost effective. Solar systems designed for combined heating and cooling will utilize the collector all year and thus are potentially more cost effective.

Figure 2. 3 Collector tilt for domestic hot water

Figure 2. 4 Collector orientation.

Ответьте на вопросы к тексту:

1. How may the tilt and orientation angle vary?

2. Why is it important to keep the collectors out of the shade?

3. What would additional deviations require?

4. What are the advantages and disadvantages of solar collectors?

5. Why are solar systems potentially more cost effective?

Упражнение №1. Переведите слова и словосочетания на русский язык.

Deviation (n.); orientation angle; allowable (adj.); significantly (adv.); performance (n.); tilt angle; rated capacity; require (v.); capture (v.); approximate (adj.); coastal area; shade (n.); anticipate (v.); structure (n.); ( solar access; in summary; provide (v.); increase (n.); save (v.); valuable (adj.); poorly (adv.); conventional system; relatively (adv.); low temperature; circumvent (v.); prove (v.); utilize (v.); potentially (adv.).

Between; enough; although; either; with; due to; and; thus.

Упражнение №2. Переведите слова и словосочетания на английский язык.

Сдвиг, отклонение; номинальная емкость; по существу, в своей основе; общепринятый; преодолевать; угол ориентации; крыша; поступление солнечной радиации; в заключении, в итоге.

Упражнение №3. Сопоставьте слово А с его определением В.

А

1. price;

2. tilt;

3. shade;

4. structure;

5. advantage.

В

1. the amount of money you have to pay for something;

2. a good or useful quality or condition that something has;

3. a movement or position in which one side of something is higher than the other;

4. something that has been built, especially something large such as a building or a bridge;

5. slight darkness or shelter from the direct light of the sun made by something blocking it.

Упражнение № 4. Найдите в тексте неличные формы глагола, определите, какими частями речи они являются, какую функцию выполняют в предложении, и переведите их на русский язык.