问题 问答题 简答题

锅炉通风的作用是什么?何为自然通风?影响自然通风能力的因素是什么?何为机械通风?电厂锅炉为什么广泛采用平衡通风?

答案

参考答案:

锅炉通风的作用是给锅炉连续送入燃烧所需要的空气,并把燃烧生成的烟气排出炉外,以保证燃烧的正常进行。自然通风是利用烟囱进行通风,即利用烟囱中热烟气与外界冷空气之间的重度差所产生的引力自行通风。影响自然通风能力的因素有空气与烟气的平均重度差,烟囱的高度。

机械通风主要是利用风机产生的压力迫使空气和烟气流动进行通风。

因为平衡通风一般在炉膛出口保持2~3mm水柱的负压,处于合理的负压下运行,所以锅炉房的安全及卫生条件较高,而且锅炉漏风量较少,是目前发电厂锅炉应用最普遍的一种通风方式。

单项选择题
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Are you a compulsive spender, or do you hold on to your money as long as possible? Are you a bargain hunter? Would you rather use charge accounts than pay cash? Your answers to these questions will reflect your personality. According to psychologists, our individual money habits not only show our beliefs and values, but can also stem from past problems.

Experts in psychology believe that for many people, money is an important symbol of strength and influence. Husbands who complain about their wives’ spending habits may be afraid that they are losing power in their marriage. Wives, on the other hand, may waste huge amounts of money because they are angry at their husbands. In addition, many people consider money a symbol of love. They spend it on their family and friends to express love, or they buy themselves expensive presents because they need love.

People can be addicted to different things — for example, alcohol, drugs, certain foods, or even television. They are compulsive in their addictions, i.e. they must satisfy these needs to feel comfortable. In the same way, according to psychologists, compulsive spenders must spend money. For people who buy on credit, furthermore, charge accounts are even more exciting than money: in other words, they feel that with credit, they can do anything. Their pleasures in spending enormous amounts are actually greater than those they get from the things they buy.

There is even a special psychology of bargain hunting. To save money, of course, most people look for sales, low prices, and discounts. Compulsive bargain hunters, however, often buy things that they don’t need just because they are cheap. They want to believe that they are helping their budgets, but they are really playing an exciting game: when they can buy something for less than other people, they feel that they are winning. Most people, experts claim, have two reasons for their behavior: a good reason for the things that they do and the real reason.

It is not only scientists, of course, who understand the psychology of spending habits, but also business people. Stores, companies, and advertisers use psychology to increase business: they consider people’s needs for love, power, or influence, their basic values, their beliefs and opinions, etc. in their advertising and sales methods.

Psychologists often use a method called “behavior therapy(疗法)” to help individuals solve their personality problems. In the same way, they can help people who feel that they have problems with money: they give them “assignments”. If a person buys something in every store that he enters, for instance, a therapist might teach him self-discipline in this way: on the first day of his therapy, he must go into a store, stay five minutes, and then leave. On the second day, he should stay for ten minutes and try something on. On the third day, he stays for fifteen minutes, asks the salesclerk a question, but does not buy anything. Soon he will learn that nothing bad will happen to him if he doesn’t buy anything, and he can solve the problem of his compulsive buying.  

小题1:If you use charge accounts, ____.

A.you pay in cash

B.you pay with credit card

C.you pay less than you should

D.you pay more than you should小题2:Compulsive bargain hunters buy things for all the following reasons except that ____.

A.the things they buy are cheap

B.they believe they can balance their budgets

C.they get psychological satisfaction

D.they really need the things they buy小题3:Behavior therapy in this case aims at____.

A.helping businessmen to increase their business

B.helping compulsive spenders to buy less

C.finding out how people will react if they are allowed to buy

D.finding out what people will do in front of a bargain小题4:The underlined word “those” in Paragraph 3 refers to ____.

A.different things

B.their addictions

C.charge accounts

D.their pleasures小题5:From the passage we can conclude that ____.

A.how you spend money reveals if you are psychologically healthy

B.money is a necessity and will bring you happiness if you have much

C.compulsive buying problems can be solved by taking some medicine

D.all businessmen understand well the psychology of customers