VDI 4661
Energetic characteristics - Fundamentals - Methodology
| Organization: | VDI |
| Publication Date: | 1 August 2014 |
| Status: | active |
| Page Count: | 52 |
| ICS Code (Energy and heat transfer engineering (Vocabularies)): | 01.040.27 |
| ICS Code (Energy and heat transfer engineering in general): | 27.010 |
scope:
Introduction
Comparison and evaluation of the energetic quality of equipment,
plants, systems and also their technical and economic optimization
is made on the basis of energetic characteristics. In most cases
these energetic characteristics are relative values some of which
are dimensionalized and others non-dimensionalized.
The various types of energy conversion can be described by the laws of thermodynamics. However, the system of equations in thermodynamics is a closed system only for ideal - i.e. reversible - processes. In practice, it is sometimes not possible to obtain an exact analytical estimation of energetic processes. Therefore energetic fundamental variables are linked to other determining factors, such as technical conditions of production, economical and social structures and environmental conditions, in a way which is too complex, and in some cases not known and therefore imponderable. Commonly, the affecting factors are stochastic and only reproducible with difficulty.
For this reason, determining all of the characteristics mentioned in this standard must be based not only on an evaluation of existing data but also on measurements which may range from simple counting to the employment of complex measurement systems. Determining energetic characteristics demands:
• the existing data be checked or a measurement concept to be implemented which provides all of the data both relevant to the problem in question and also which have an influence on the process and its associated energy consumption, providing the data in the form and way required for obtaining an answer to the problem in question
• the measured data be processed and presented in a manner so as to enable recognition and quantification of the parameters affecting and determining power and energy requirements, the effects of these parameters and also the technical quality of the energy conversion and utilization
The task of standard VDI 4661 is:
• to define both physical and technical terms
• to define a number of typical special characteristics
• to provide examples of how characteristics are determined, quantified and utilized
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