88TV01H-E GJR2346500R1041 88TV01E 数字量输出模块 ABB
工厂内衬的火箱和直径为4英尺的阀盖，以及当今的高科技熔炉。尺寸减少，容量增加，重量增加
相对成本降低，燃料燃烧效率提高，可靠性提高。
泵和风扇的变速驱动装置具有：
已改进到通用应用的程度。经营成本
降低速度以“匹配负载”的优势已为人所知
在工业中使用了很长时间，但技术需要时间
为商用开发可靠、低成本、变速控制器
例如现在用于HVAC应用中的变频驱动器。
如果价值工程似乎与1.2节中的问题解决共享一些共同的分析技术，则双重呈现是有意的。这两种讨论都是解决问题和改善服务的方法。一个是对导师的例子的解释，
暖通空调工程基础：1部分
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暖通空调工程基础：1部分5
二种是公开记录的正式程序。暖通空调
如果系统设计师能够致力于
分析思维过程，定义问题，提出解决方案，确定佳方法，后以可信和令人信服的方式提出解决方案。
1.4规范和规定
任何暖通空调设计师都不应首先了解并熟悉管理和规范建筑施工、产品设计和制造、工程师资格的各种规范和条例，然后才承担设计任务
实践等。规范通常在以下基础上具有法律效力
保护公共安全和福利。可施加处罚
对于违反既定规范的人，以及违规装置
可能会被谴责，并被视为不适用于强制执行
当局。作为年轻的设计从业者，我们被建议“卷曲”
直到我们完全熟悉
它的戒律。
对于建筑物的结构，规范特别明确
完整性、电气安全、管道卫生、燃油设备
和系统、防火探测和保护、生命安全和
残疾人无障碍建筑、节能、室内空气
这些区域中的每一个都对HVAC的设计有影响
系统。
特定的代码在采用和实现上有足够的多样性，因此本书列出任何细节都是不明智的。这个
暖通空调系统设计师只需知道，生活并非没有
限制该系统将符合规范，否则将获得建造许可
并且将拒绝使用；而设计师故意违反规范只会带来极大的个人风险。
每个暖通空调设计任务的推荐做法是：
对当地执行的法规和条例进行初步审查，
彻底熟悉适用段落，并
虔诚地遵循规定的做法，即使这种做法似乎会扼杀创造力。
有时，代码约束似乎违反或干扰
构造的目标。在这种情况下，通常可以向管理局请求变更。没有接受的保证，但没有冒险，没有收获。良好的准备会带来希望和理解，并将您与
无休无止的江湖骗子，他们试图回避个人隐私的法规和条例
88TV01H-E GJR2346500R1041 88TV01E 数字量输出模块 ABB
88TV01H-E GJR2346500R1041 88TV01E 数字量输出模块 ABB
actory-lined firebox and 4-ft-diameter bonnet, and the hightechnology furnaces of today. Size is down, capacity is up, weight is
down, relative cost is down, fuel combustion efficiency is up, and reliability is debatably up.
Variable-speed drives for pumps and fans are devices which have
been improved to the point of common application. The operating-cost
advantages of reduced speed to ‘‘match the load’’ have been known
and used in industry for a long time, but technology has taken its time
to develop reliable, low-cost, variable-speed controllers for commercial
motors, such as variable-frequency drives now used in HVAC applications.
If value engineering seems to share some common analytical technique with Sec. 1.2 on problem solving, the dual presentation is intentional. Both discussions are approaches to solving problems, to improving service. The first is an interpretation of a mentor’s example,
HVAC Engineering Fundamentals: Part 1
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HVAC Engineering Fundamentals: Part 1 5
the second is a publicly documented, formal procedure. The HVAC
system designer will benefit greatly if she or he can commit to an
analytical thought process which defines the problem, proposes solutions, identifies the optimum approach, and finally presents the solution in a credible and compelling way.
1.4 Codes and Regulations
No HVAC designer should undertake a design task without first having an awareness of and hopefully a working familiarity with the various codes and ordinances which govern and regulate building construction, product design and fabrication, qualification of engineers in
practice, etc. Codes generally are given the force of law on the basis
of protecting the public safety and welfare. Penalties may be applied
to those who violate established codes, and the offending installation
may be condemned and regarded as unsuitable for use by enforcement
authorities. As young design practitioners, we were advised to ‘‘curl
up with a good code book’’ until we became thoroughly familiar with
its precepts.
Codes are particularly definitive regarding a building’s structural
integrity, electrical safety, plumbing sanitation, fuel-fired equipment
and systems, fire prevention detection and protection, life safety and
handicapped accessibility in buildings, energy conservation, indoor air
quality, etc. Each of these areas has an impact on the design of HVAC
systems.
Particular codes are sufficiently diverse in their adoption and implementation that it is unwise for this book to list any specifics. The
HVAC system designer should simply know that life is not without
constraint; that systems will conform to codes, or else a permit to build
and use will be denied; and that willful violation of codes by the designer is done only at great personal risk.
The recommended practice for every HVAC design assignment is to
make an initial review of the locally enforced codes and regulations,
to become thoroughly familiar with the applicable paragraphs, and to
religiously follow the prescribed practices, even though such an approach seems to stifle creativity.
Occasionally code constraints seem to violate or interfere with the
objective of a construction. At these times, it is often possible to request a variance from the authority. There is no guarantee of acceptance, but nothing ventured, nothing gained. Good preparation generates hope and understanding, and differentiates you from the
unending stream of charlatans who seek to sidestep codes and regulations for personal f
88TV01H-E GJR2346500R1041 88TV01E 数字量输出模块 ABB
