Air Conditioning Systems
Project Plan
State-in-the-art systems have two main drawbacks. First is trivial – not a pleasant look. Shown in Fig 1.
The second – too large energy consumption. Some additional illustrations may be found in the attachment.
Possible partners/investors of the project may be city hall, building companies, the systems manufacturers (Tadiran).
Fig. 1 Sample of the outer unit mounting.
2.1 First stage of development.
As planned at the first stage, all existing system components may be used. The only possibility will be checked to rearrange them, to build inside the wall. Shown in Fig.2.
2.2 Second stage of development.
At a second stage a new design and experimental investigation is planned to be performed. Air to Air system with the same relation to building in the wall. As Shown in Fig.3
Fig.2 Build in arrangement
Fig.3 Air to Air Conditioner
Air to air conditioning system
1. The object and aim.
As signed in the preface to the project the aim is research and development of the air conditioning system with minimal drawbacks for domestic application. Two pronounced aims are: built-in a wall and energy consumption minimization.
2. Analogues and principal parameters.
Two widely existent companies in the Israeli market are “Electra” and “Tadiran”. Both present a classic system arrangement: the inside unit, includes an inner air circuit & heat exchanger, and an outer unit - air circuit & heat exchanger; refrigerant with phase change as heat carrier. “Tadiran” does not sign in a data the coefficient of power (the subject of interest - COP). Data of “Electra” products include COP ( (מקדם up to 4. Another type of devices as heat pumps demonstrate COP up to 6 and even to 10 in heating mode. So, preliminary accepted parameter values are: heat/cool delivery – 4kW with power consumption 1kW (built in the wall configuration); COP – 4.
3. Stage 2 design.
The device layout is firstly presented in the project card on the website [1]. The project aim, signed there, is to use a heat carrier without physical phase exchange - gas only. The trivial drawback of this way is restricted heat transfer per mass unit. On the other side, the same physical principle of function may be used for air conditioning not only in the classic way. The device function may be defined as: heat transfer from the side of low potential energy to the second side of the low potential energy state as well. Wherein, high potential energy consumption may be rather low, because of the energy balance in the process remains without changes. So, it seems rightful to suppose some alternative ways for the process to be performed.
3.1 Elements for analysis.
Air conditioning with a gas heat carrier require two machines for function: a gas compressor and a gas expander. First design of the device may be with full analogy to the classic one: inner air circuit – air fan and heat exchanger; heat carrier gas circuit – compressor and expander; outer air circuit – air fan and heat exchanger.
3.1.1 Outer and inner air circuits.
Outer and inner circuits with the only changes to adapt them to the built in structure.
3.1.2 Gas heat carrier circuit.
The consequence function of the compressor and the expander defines their type as volume machines. Gas’s low range of pressure makes it preferable to use vane-type machines as the most effective.
Several probes of machine geometry were checked with the main parameters calculations and heat transfer process simulation. Finally the shape and dimensions were defined in reference to the desirable in part 2 values of power consumption and COP. The System Principal Diagram presented in Fig.1. The vane machine mock-up design presented in Fig. 2
Several probes of calculations were fulfilled with three kinds of gases that optionally may be applied as heat carriers. The results and additional data are presented in another file.
3.2 The heat transfer process calculation.
The method of comparison with standard gas states with iterations was finally chosen as most reliable. Standard states data from two sources were used – Diagrams as an appendix to Fundamentals of Cryogenics Handbook [2] and Tables of Thermal Properties of Gases [3].
Fig.1 The System of Air Conditioning Diagram.
Fig.2 Vane machine mock-up design.
References.
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Web site: www.nudelman-engineering.com /Projects/Domestic Thermal Systems/ .
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Tables of Thermal Properties of Gases., USA department of commerce, National Bureau of Standards Circular 564, Issued November 1, 1955. Comprising by: Joseph Hilsenrath, Charles W. Beckett, William S. Benedict, Lilia Fano, Harold J. Hoge Joseph F. Masi, Ralph L. Nuttall, Yeram S. Touloukian, Harold W. Woolley. National Bureau of Standards Circular 564. Issued November 1, 1955. For sale by the Superintendent of Documents, U. S. Government Printing Office, ...
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The Gases Thermodynamic States Diagrams, as appendix to Handbook of Fundamentals of Cryogenics, M., Energia, 1973
B. Nudelman 10.06.2023