scholarly journals Analysis of supplemental dehumidification for increased energy efficiency of shoulder seasons based on climate change predictions in Austin Texas

2021 ◽  
Vol 2042 (1) ◽  
pp. 012182
Author(s):  
B Marshall ◽  
J Felkner ◽  
Z Nagy

Abstract This research project compared a standard vapor compression system and a standard desiccant dehumidification system with heat wheel to determine if there was some potential energy savings for “shoulder season” hours in Austin Texas. “Shoulder season” hours as defined in the paper are hours during which the dry bulb temperature falls within the American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) comfort bound but the humidity is above the comfortable humidity point. These hours are normally addressed with vapor compression systems which dehumidify by cooling the air under the comfort setpoint to dehumidify, which is wasteful of energy. The study found that for these shoulder season hours a desiccant dehumidification system was around 4.5 times more energy efficient at reaching comfort setpoints if free heating was used for drying the desiccant.

2010 ◽  
Vol 107 ◽  
pp. 93-97
Author(s):  
José M. Portela ◽  
Andrés Pastor ◽  
Milagros M. Huerta ◽  
Manuel Otero ◽  
Rafael E. González

Climate change and increasing energy prices threaten the planet and the economy. The European Union has promised to take the lead, through a reduction in greenhouse gases by 20 to 30% and a 20% energy savings by 2020. In this context, the EU is about to ban some of the most inefficient lightbulbs for everyday. Lighting would set the limit at the level of CFLs/LEDs (most energy efficient existing lamps). The energy savings would be maximized, the target is 86 TWh of electricity saved per year in the EU by 2020. To discover how to use different materials in this technology is a high-priority as it shows the advance; maybe this is the future of lighting.


The progressive development of the economy of the Republic of Kazakhstan is impossible without solving the issues of increasing energy efficiency and energy conservation. These issues are very relevant in the construction sector of Kazakhstan. Housing facilities, on average, consume 2-3 times more heat per square meter, than buildings in Europe. However, in Kazakhstan until now there is no methodology for determining the energy efficiency of buildings and structures that meets modern requirements. The methodology discussed in this article is harmonized with EU requirements and establishes a method for calculating the annual energy consumption of buildings for heating, hot water, ventilation and air conditioning, taking into account auxiliary energy for the operation of these systems, and is intended for use in the design of new construction, reconstruction (modernization) residential and public buildings, as well as operated buildings and structures.


Author(s):  
Vikas Kumar ◽  
Gulshan Sachdeva ◽  
Sandeep Tiwari ◽  
Parinam Anuradha ◽  
Vaibhav Jain

A conventional vapor compression refrigeration system (VCRS) cascaded with a heat-assisted ejector refrigeration system (ERS) has been experimentally analyzed. Cascading allows the VCRS to operate at lower condenser temperatures and thus achieve a higher coefficient of performance. In this cascaded system, the condenser of the vapor compression system does not dissipate its heat directly to the evaporator of the ERS; instead, water circulates between the condenser of VCRS and the evaporator of ERS to exchange the heat. Seven ejectors of different geometries have been used in the ERS; however, all the ejectors could not maintain thermal equilibrium at the desired operating conditions. The compressor of the cascaded VCRS consumed 1.3 times less power than the noncascaded VCRS. Furthermore, the cascaded system provided a maximum 87.74% improvement in COP over the noncascaded system for the same operating conditions. The performance of the system remained constant until the critical condenser pressure of the ERS.


2021 ◽  
Vol 122 ◽  
pp. 97-109
Author(s):  
Yudong Xia ◽  
Qiang Ding ◽  
Nijie Jing ◽  
Aipeng Jiang ◽  
Xuejun Zhang ◽  
...  

1983 ◽  
Vol 105 (4) ◽  
pp. 681-685 ◽  
Author(s):  
F. Freudenstein ◽  
M. Mayourian ◽  
E. R. Maki

The energy loss in cam-follower systems due to friction between moving parts can be a significant contributor to the power loss in machinery. Considering the total number of cam-operated machines in manufacturing and other operations, the energy savings obtainable by improving the efficiency of the average cam-follower system by even a small percentage would be significant. In this investigation a new rating factor—an energy-loss coefficient proportional to the energy loss at the cam-follower interface—has been defined and evaluated. The rating factor relates to energy efficiency in a manner analogous to the way in which the well-known rating factors for velocity, acceleration, and shock relate to the kinematic characteristics of the cam-follower system. Two cam-follower configurations have been considered: 1) a follower motion governed by both cam and return spring, and 2) a follower positively driven by the cam. In both cases it was found that cam curves with identical rise and rise times can differ substantially in energy efficiency thereby demonstrating the significance of an energy-optimization strategy in the design of cam-follower systems. The nature of the functional dependence of the energy loss on system parameters has been identified and a minimum energy-loss limit established.


Author(s):  
Pawel Olszewski ◽  
Claus Borgnakke

The aim of this research is to estimate the influence of compressed air volumetric capacity on the energy consumption in systems equipped with oil-lubricated screw compressors. A mathematical model of oil-lubricated screw compressors has been proposed. The model is verified by comparing with real measurements, and overall uncertainty analysis is estimated. An in-house developed numerical code (c++) is used to calculate the energy consumption in 252,000 combinations. The final result can be used to estimate the energy efficiency of existing air systems and to assess potential energy savings due to changes in the operation of the system and its control strategy.


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