HIEE405053R1 UN0803B-P V1 UN0803B 模拟量PBC线路板 ABB
茎发出声音。
当周期运动的影响
一件设备的一部分被带入并穿过结构
根据定义，感觉到刺激或冒犯的点。
任何稍微失去平衡的旋转设备都可以设置
增加振动。振动通常在结构中传递到远处
要点。坐在书桌旁的人可以感觉到地板或书桌
振动。实验室工作台上的一盘液体可能会呈现波形
表面上的结构振动。即使暴风雨也能
导致建筑物震动，空气在管道中流动或
管道中流动的流体会引起振动和噪音。
好通过平衡和隔离来控制振动。平衡
移动部件消除了其原点的振动。对于大型元件，如风扇、压缩机和发动机，采用弹簧隔离
或弹性垫是常见的做法。较低频率的振动需要更多的初始弹簧偏转才能有效。必须消除振动元件与其环境的任何硬物理连接。因此，所有管道和导管或管道连接必须灵活
有联系的。这也有助于确保设备：
不承受连接管道的重量。
关于这一问题的进一步讨论，见20章和参考文献7。
1.10节能
定期的国际活动提醒我们能源在
发达国家的经济福祉。共同的能力
工业国家的人民比国王过着更富裕的生活
而过去的女王与能源仆人直接相关。
交通、通信、农业、住房、制造业、，
卫生保健服务等都由
可用的能源供应，包括燃料和电力。
同时，可用能源也存在明显的限制
来源。尽管有了新的发现，但煤炭、石油、天然气和其他化石或有机燃料的总量仍可以估算，今年的数据低于
后一个。发展的潜力有限
可再生能源，全部来自太阳，如木材、风能、水力发电等。就规模而言，核能（当时的聚变概念）是已知的能带来希望的能源
能够使三世界工业化并维持一个不断增长的世界
人口超过几个世纪而不是几十年。然而，核武器的使用
在美国，权力深陷政治流沙。
暖通空调系统设计师的结论，所有这些
定义是能源管理和能源消耗，是吗
暖通空调工程基础：1部分
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12一章
这是一项国际任务，也是一项道德和经济上的义务，以设计能源使用适度的系统。尽管美国缺乏明确的国家能源政策，
地方和区域能源规范为暖通空调系统设计师提供了一些指导。这些规范鼓励建筑施工
具有较低固有能量要求的照明系统
其获得更多的照明
HIEE405053R1 UN0803B-P V1 UN0803B 模拟量PBC线路板 ABB
HIEE405053R1 UN0803B-P V1 UN0803B 模拟量PBC线路板 ABB
stem-generated sound.
Vibration becomes a problem when the effects of the cyclical motion
of a piece of equipment are carried into and through the structure to
a point where it is sensed, by definition, as an irritation or offense.
Any rotating piece of equipment that is slightly out of balance can set
up a vibration. Vibrations are often carried in structures to remote
points. A person sitting at a desk may sense the floor or the desk
vibrating. A pan of liquid on a laboratory table may exhibit waveforms
on the surface from structural vibrations. Even as windstorms can
cause buildings to shake and tremble, so can air moving in ducts or
fluid moving in pipes give rise to vibrations and noise.
Vibration is best controlled by balance and isolation. Balance of
moving components eliminates vibration at its origin. For large elements such as fans, compressors, and engines, isolation with springs
or resilient pads is common practice. Lower-frequency vibrations require more initial spring deflection to be effective. The vibrating element must be relieved of any hard physical connection to its environment. Hence all pipe and conduit or duct connections must be flexibly
connected. This is also helpful in making sure that the equipment does
not carry the weight of the attached piping.
See Chap. 20 and Ref. 7 for further discussion of this issue.
1.10 Energy Conservation
Periodic international events remind us of the vital role of energy in
the economic well-being of developed countries. The ability of common
folk in the industrial nations to live more opulent lives than the kings
and queens of yesteryear is directly related to the energy servant.
Transportation, communication, agriculture, housing, manufacturing,
health care services, and the like are all facilitated by the readily
available supplies of energy, both fuel and power.
At the same time, there are recognizable limits to available energy
sources. Despite new discoveries, coal, oil, gas, and other fossil or organic fuels can be estimated in total volume, with less this year than
there was last. There is a finite limit to the potential development of
renewable energies, all derived from the sun, such as wood, wind, hydropower, etc. In terms of magnitude, nuclear power (the fusion concept, at that) is the only known energy source that offers hope of being
able to industrialize the third world and to sustain a growing world
population over centuries rather than decades. Yet the use of nuclear
power is mired in political quicksand in the United States.
The conclusion for the designer of HVAC systems, all of which by
definition are energy-managing and energy-consuming, is that there
HVAC Engineering Fundamentals: Part 1
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12 Chapter One
is an international mandate as well as a moral and economic imperative to design systems which are modest in their use of energy. Although the United States lacks a well-defined national energy policy,
local and regional energy codes give some direction to the HVAC systems designer. These codes encourage the construction of buildings
which have lower inherent energy requirements, lighting systems
which derive more illumination
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