制冷与空调专业英语第2版 林慧珠 主编 1-4新.pptVIP

Unit One Lesson 1 Air Lesson 2 The Need of Conditioning Lesson 3 The Cleaning of Air Lesson 4 Thermal Storage Lesson 4 Thermal Storage New Words Expressions: Text Notes to the Text Exercise Lesson 4 Lesson 4 Text Thermal storage is the temporary storage of high or low-temperature energy for later use.1 Examples of thermal storage are the storage of solar energy for night heating and the storage of summer heat for winter use, the storage of winter ice for space cooling in the summer, and the storage of heat or coolness generated electrically during off-peak hours for use during subsequent peak hours. Most thermal storage applications involve a 24-hours storage cycle, although weekly and seasonal cycles are also used. Text: When the period of energy availability is longer than the period of energy use, thermal storage permits the installation of smaller heating or cooling equipment than would otherwise be required. In many cases, storage can provide benefits for both heating and cooling, either simultaneously or at different times of the year. Text: Conditions favoring thermal storage include high loads of relatively short duration; high electric power demand charges; low cost electrical energy during off-peak hours; need for cooling backup in case of power outage or a refrigeration plant failure (only chilled water pumps must be powered by the emergency generator), need to provide cooling for small after-hour loads such as cooling of restaurants, midheight elevator equipment rooms, individual offices, and computer rooms; building expansion (installation of storage may eliminate the need for heating/cooling plant expansion); need to provide a fire fighting reservoir; need to supplement a limited capacity generation plant; and others.2 Text: In sensible heat storage, storage is accomplished by raising or lowering the temperature of the storage medium, i.e. , water, rock beds, bricks, sand, or soil. Text: In latent heat storage