中英文对照外文翻译
英文：
How Air Conditioners Work and energy conrvation
technology rearch
假期见闻作文Abstract：An air conditioner is basically a refrigerator without the insulated box. It us the evaporation of a refrigerant, like Freon, to provide cooling. The mechanics of the Freon evaporation cycle are the same in a refrigerator as in an air conditioner.
Keywords：water towers 、weather-resistant、compressor、energy conrvation When the temperature outside begins to climb, many people ek the cool comfort of indoor air conditioning. Like water towers and power lines, air conditioners are one of tho things that we e every day but ldom pay much attention to. Wouldn't it be nice to know how the indispensable machines work their magic? In this article, we will examine air conditioners -- from small to huge -- so you know more about what you're eing!
The Many Faces of Cool职称外语考试有效期
Air conditioners come in various sizes, cooling capacities and prices. One type that we e all the time is the window air conditioner.
Window air conditioners are an easy and economical way to cool a small area. Most people who live in suburban areas usually have one of the in their backyard: If you live in an apartment complex, this is probably a familiar sight: Most business and office buildings have condensing units on their roofs, and as you fly into any airport you notice that warehous and malls may have 10 or 20 condensing
units hidden on their roofs:
And then if you go around back at many hospitals, universities and office complexes, you find large cooling towers that are connected to the air conditioning system:
Even though each of the machines has a pretty distinct look, they all work on the same principles. Let's take a clor look.
The Basic Idea
An air conditioner is basically a refrigerator without the insulated box. It us the evaporation of a refjourney是什么意思
rigerant, like Freon, to provide cooling. The mechanics of the Freon evaporation cycle are the same in a refrigerator as in an air conditioner. According to the Merriam-Webster Dictionary Online, the term Freon is generically "ud for any of various conditioner. According to the Merriam-Webster Dictionary Online, the term Freon is generically "ud for any of various nonflammable fluorocarbons ud as refrigerants and as propellants for aerosols."
This is how the evaporation cycle in an air conditioner works (See How Refrigerators Work for complete details on this cycle):
1.The compressor compress cool Freon gas, causing it to become hot,
high-pressure Freon gas (red in the diagram above).
2.This hot gas runs through a t of coils so it can dissipate its heat, and it condens into a liquid.
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3.The Freon liquid runs through an expansion valve, and in the process it evaporates to become cold, low-pressure Freon gas (light blue in the diagram above).
4.This cold gas runs through a t of coils that allow the gas to absorb heat and cool down the air inside the building.
Mixed in with the Freon is a small amount of a light weight oil. This oil lubricates the compressor.
bubblegumWindow Units
A window air conditioner unit implements a complete air conditioner in a small
space. The units are made small enough to fit into a standard window frame. You clo the window down on the unit, plug the unit in and turn it on to get cool air. If you take the cover off of an unplugged window unit, you will find that it contains:
A compressor
An expansion valve
平安夜 英文A hot coil (on the outside)
A chilled coil (on the inside)
A control unit
The fans blow air over the coils to improve their ability to dissipate heat (to the outside air) and cold (
剑桥商务英语官网to the room being cooled).
BTU and EER
Most air conditioners have their capacity rated in British thermal units (BTU). Generally speaking, a BTU is the amount of heat required to rai the temperature of one pound (0.45 kg) of water 1 degree Fahrenheit (0.56 degrees Celsius). Specifically, 1 BTU equals 1,055 joules. In heating and cooling terms, 1 "ton" equals 12,000 BTU.
A typical window air conditioner might be rated at 10,000 BTU. For comparison, a typical 2,000-square-foot (185.8 m2) hou might have a 5-ton (60,000-BTU) air conditioning system, implying that you might need perhaps 30 BTU per square foot. (Keep in mind that the are rough estimates. To size an air conditioner for your specific needs, contact an HV AC contractor.)
The energy efficiency rating (EER) of an air conditioner is its BTU rating over its wattage. For example, if a 10,000-BTU air conditioner consumes 1,200 watts, its EER is 8.3 (10,000 BTU/1,200 watts). Obviously, you would like the EER to be as high as possible, but normally a higher EER is accompanied by a higher price.
Is the higher EER is worth it?
george zimmerman
Let's say that you have a choice between two 10,000-BTU units. One has an EER of 8.3 and consumes 1,200 watts, and the other has an EER of 10 and consumes
1,000 watts. Let's also say that the price difference is $100. To understand what the payback period is on the more expensive unit, you need to know:
1.Approximately how many hours per year you will be operating the unit
2.How much a kilowatt-hour (kWh) costs in your area
Let's say that you plan to u the air conditioner in the summer (four months a year) and it will be operating about six hours a day. Let's also imagine that the cost in your area is $0.10/kWh. The difference in energy consumption between the two units is 200 watts, which means that every five hours the less expensive unit will consume 1 additional kWh (and therefore $0.10 more) than the more expensive unit.
Assuming that there are 30 days in a month, you find that during the summer you are operating the air conditioner:
Since the more expensive unit costs $100 more that means that it will take about ven years for the
more expensive unit to break even.
See this page for a great explanation of asonal energy efficiency rating (SEER).
Split-system Units
A split-system air conditioner splits the hot side from the cold side of the system。
The cold side, consisting of the expansion valve and the cold coil, is generally placed into a furnace or some other air handler. The air handler blows air through ducts. The hot side known as the condensing unit, lives outside the building. The unit consists of a long, spiral coil shaped like a cylinder. Inside the coil is a fan, to blow air through the coil, along with a weather-resistant compressor and some control logic. This approach has evolved over the years becau it is low-cost, and also becau it normally results in reduced noi inside the hou (at the expen of incread noi outside the hou). Besides the fact that the hot and cold sides are split apart and the capacity is higher (making the coils and compressor larger), there is no difference between a split-system and a window air conditioner.
In warehous, business, malls, large department stores, etc., the condensing unit normally lives
on the roof and can be quite massive. Alternatively, there may be many smaller units on the roof, each attached inside to a small air handler that cools a specific zone in the building.
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Let's take a look now at a chilled-water air conditioner.
Chilled-water System
In larger buildings and particularly in multi-story buildings, the split-system approach begins to run into problems. Either running the pipe between the condenr and the air handler exceeds distance limitations (runs that are too long start to cau lubrication difficulties in the compressor), or the amount of duct -work and the length of ducts become unmanageable. At this point, it is time to think about a chilled-water system.
In a chilled-water system, the entire air conditioner lives on the roof or behind the building. It cools water to between 40 and 45 F (4.4 and 7.2 C). This chilled water is then piped throughout the building and connected to air handlers as needed. There is no practical limit to the length of a chilled-water pipe if the system can be got well - insulated.
Whenever you walk behind a building and find a unit that has large quantities of water running through a plastic mesh, you will know you have found a cooling tower!
In many office complexes and college campus, cooling towers and air conditioning equipment are centralized, and chilled water is routed to all of the buildings through miles of underground pipes.
学美甲Bad on dynamic load track central air-conditioning system entire clod loop energy conrvation technology rearch.
1. introductions
The energy conrvation may say is the building character automatic control system starting point and the home to return to. It is well known, in the intelligent
