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The Experiment and Simulation of Solid Desiccant Dehumidification for Air-Conditioning System in a Tropical Humid Climate  [PDF]
Juntakan Taweekun, Visit Akvanich
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.51A021
Abstract:

The aim of this research was to study and design a solid desiccant dehumidification system suitable for tropical climate to reduce the latent load of air-conditioning system and improve the thermal comfort. Different dehumidifiers such as desiccant column and desiccant wheel were investigated. The ANSYS and TRASYS software were used to predict the results of dehumidifiers and the desiccant cooling systems, respectively. The desiccant bed contained approximately 15 kg of silica-gel, with 3 mm average diameter. Results indicated that the pressure drop and the adsorption rate of desiccant column are usually higher than those of the desiccant wheel. The feasible and practical adsorption rate of desiccant wheel was 0.102 kgw/h at air flow rate 1.0 kg/min, regenerated air temperature of 55?C and at a wheel speed of 2.5 rpm. The humidity ratio of conditioning space and cooling load of split-type air conditioner was decreased to 0.002 kgw/kgda (14%) and 0.71 kWth (19.26%), respectively. Consequently, the thermal comfort was improved from 0.5 PMV (10.12% PPD) to 0.3 PMV (7.04% PPD).

Fuzzy operant conditioning probabilistic automaton bionic autonomous learning system and robot self-balancing control
模糊操作条件概率自动机仿生自主学习系统和机器人自平衡控制

RUAN Xiao-gang,CAI Jian-xian,
阮晓钢
,蔡建羡

控制理论与应用 , 2010,
Abstract: A fuzzy operant conditioning probabilistic automaton(OCPA) bionic autonomous learning system is constructed based on Skinner operant conditioning theory and combined with the probabilistic automaton and fuzzy inference for realizing a two-wheeled robot self-balancing control. The learning system is a stochastic mapping from state sets to operant action sets. The optimal action for controlling the system is stochastically learned from the operant action set by adopting operant conditioning learning algorithm; in the same time the orientation value information of the learned operant action is used to adjust the operant conditioning learning algorithm. In addition, the action entropy is added to verify the self-learning and self-organizing ability of the learning system. In the simulation, a two-wheeled robot self-balancing control is realized, demonstrating the feasibility of the fuzzy OCPA learning system.
Subsystem Codes  [PDF]
Salah A. Aly,Andreas Klappenecker,Pradeep Kiran Sarvepalli
Mathematics , 2006,
Abstract: We investigate various aspects of operator quantum error-correcting codes or, as we prefer to call them, subsystem codes. We give various methods to derive subsystem codes from classical codes. We give a proof for the existence of subsystem codes using a counting argument similar to the quantum Gilbert-Varshamov bound. We derive linear programming bounds and other upper bounds. We answer the question whether or not there exist [[n,n-2d+2,r>0,d]]q subsystem codes. Finally, we compare stabilizer and subsystem codes with respect to the required number of syndrome qudits.
Moisture transfer resistance method for liquid desiccant dehumidification analysis and optimization
Lin Chen,Qun Chen,Zhen Li,ZengYuan Guo
Chinese Science Bulletin , 2010, DOI: 10.1007/s11434-010-0006-9
Abstract: The concepts of entransy, entransy dissipation and transfer resistance are introduced into liquid desiccant dehumidification analysis to reveal the irreversibility and moisture transfer resistance between moist air and liquid desiccant. By analyzing a typical water (vapor) transfer process coupled with heat transfer, we define the concepts of mass entransy of water and its dissipation, derive the expression of moisture transfer resistance (MTR) that reflects the irreversibility of water transfer during dehumidification processes, and also point out the relationship between MTR and dehumidification performance. With these concepts, both adiabatic and internal cooling liquid desiccant dehumidification systems with various operation conditions are analyzed and optimized. It is found that for the adiabatic dehumidification system, increasing the mass transfer coefficient leads to the reduction of MTR, and consequently, the improvement of dehumidification performance. Meanwhile, for the dehumidification system with internal cooling, in order to reduce the MTR and improve the dehumidification performance, pre-cooling should be centralized ahead of the liquid desiccant inlet when the flow rates ratio of air to desiccant is small, whereas, uniform cooling should be applied when the flow rates ratio of air to desiccant is large.
Efficiency evaluating of air conditioning system with air dehumidification section
E.M. Titova,O.V. Averyanova
Magazine of Civil Engineering , 2011,
Abstract: The upward trend of energy resources cost, reducing OF resource reserves, yearly growing requirement of heat energy led to the need of careful selection of HVAC system and economic justification of this choice. In this article on the example of indoor pool the most economically efficient variant of climatic parameters for high humidity areas has been selected. The calculation of operating, capital and reduced costs has been done. The reliability estimation and efficiency evaluating of the systems also have been done.
Air Conditioning Systems from a 2nd Law Perspective  [PDF]
Luigi Marletta
Entropy , 2010, DOI: 10.3390/e12040859
Abstract: In this paper exergy analysis is used to assess the performance of the three most common air conditioning plant schemes: all-air, dual-duct and fan-coil systems. The results are presented in terms of flow diagrams to provide a clear picture of the exergy flow across the systems. The most relevant outcomes are that the air cooling and dehumidification is the process most responsible for the exergy loss and that the exergy efficiency of the overall systems is rather low; thus the quest for more appropriate technologies. Solar-assisted air-conditioning is also discussed, outlining the possibilities and the constraints.
An evaporative and desiccant cooling system for air conditioning in humid climates
Camargo, J. R.;Godoy Jr, E.;Ebinuma, C. D.;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2005, DOI: 10.1590/S1678-58782005000300005
Abstract: evaporative cooling operates using water and air as working fluids. it consists in water evaporation, through the passage of an air flow, thus decreasing the air temperature. this system has a great potential to provide thermal comfort in places where air humidity is low, being, however, less efficient where air humidity is high. a way to solve this problem is to use dehumidifiers to pre-conditioning the process air. this paper presents a system that can be used in humid climates coupling desiccant dehumidification equipment to evaporative coolers. the paper shows, initially, the main characteristics of the evaporative cooling and of the adsorption dehumidification systems. later on the coupled systems, in which occurs a dehumidification by adsorption in a counter flow rotary heat exchanger following the evaporate cooling of the air in evaporative coolers, are analyzed. the thermodynamic equations of state are also presented. following, this paper analyzes some operation parameters such as: reactivation temperature, r/p relationship (reactivation air flow/ process air flow) and the thermodynamic conditions of the entering air flow. the paper shows the conditions for the best operation point, with regard to thermal comfort conditions and to the energy used in the process. in addition this paper presents an application of the system in different climate characteristics of several tropical and equatorial cities.
An evaporative and desiccant cooling system for air conditioning in humid climates  [cached]
Camargo J. R.,Godoy Jr E.,Ebinuma C. D.
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2005,
Abstract: Evaporative cooling operates using water and air as working fluids. It consists in water evaporation, through the passage of an air flow, thus decreasing the air temperature. This system has a great potential to provide thermal comfort in places where air humidity is low, being, however, less efficient where air humidity is high. A way to solve this problem is to use dehumidifiers to pre-conditioning the process air. This paper presents a system that can be used in humid climates coupling desiccant dehumidification equipment to evaporative coolers. The paper shows, initially, the main characteristics of the evaporative cooling and of the adsorption dehumidification systems. Later on the coupled systems, in which occurs a dehumidification by adsorption in a counter flow rotary heat exchanger following the evaporate cooling of the air in evaporative coolers, are analyzed. The thermodynamic equations of state are also presented. Following, this paper analyzes some operation parameters such as: reactivation temperature, R/P relationship (reactivation air flow/ process air flow) and the thermodynamic conditions of the entering air flow. The paper shows the conditions for the best operation point, with regard to thermal comfort conditions and to the energy used in the process. In addition this paper presents an application of the system in different climate characteristics of several tropical and equatorial cities.
Subsystem Code Constructions  [PDF]
Salah A. Aly,Andreas Klappenecker
Mathematics , 2007,
Abstract: Subsystem codes are the most versatile class of quantum error-correcting codes known to date that combine the best features of all known passive and active error-control schemes. The subsystem code is a subspace of the quantum state space that is decomposed into a tensor product of two vector spaces: the subsystem and the co-subsystem. A generic method to derive subsystem codes from existing subsystem codes is given that allows one to trade the dimensions of subsystem and co-subsystem while maintaining or improving the minimum distance. As a consequence, it is shown that all pure MDS subsystem codes are derived from MDS stabilizer codes. The existence of numerous families of MDS subsystem codes is established. Propagation rules are derived that allow one to obtain longer and shorter subsystem codes from given subsystem codes. Furthermore, propagation rules are derived that allow one to construct a new subsystem code by combining two given subsystem codes.
Propagation Rules of Subsystem Codes  [PDF]
Salah A. Aly
Mathematics , 2008,
Abstract: We demonstrate propagation rules of subsystem code constructions by extending, shortening and combining given subsystem codes. Given an $[[n,k,r,d]]_q$ subsystem code, we drive new subsystem codes with parameters $[[n+1,k,r,\geq d]]_q$, $[[n-1,k+1,r,\geq d-1]]_q$, $[[n,k-1,r+1,d]]_q$. The interested readers shall consult our companion papers for upper and lower bounds on subsystem codes parameters, and introduction, trading dimensions, families, and references on subsystem codes [1][2][3] and references therein.
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