Energy Recovery Methods in Adsorption Refrigeration Units

2017 ◽  
Author(s):  
Andrzej Grzebielec ◽  
Adam Szelągowski ◽  
Adam Ruciński
Keyword(s):  
Energy Loss ◽  
Thermal Wave ◽  
Energy Recovery ◽  
Type Systems ◽  
Adsorption Refrigeration ◽  
Wave Type ◽  
Recovery Processes ◽  
Refrigeration Unit ◽  
The One ◽  
Heat And Mass Recovery

Adsorption refrigeration systems, as opposed to absorption type operate in a cyclic manner. The result is that at the beginning of each process must be fed into the adsorber state in which they will adsorb or desorb a refrigerant. In the case of two adsorbers at the start of a cycle, the one of the adsorber must be refrigerated while the second has to be heated. These processes are causing unnecessary energy loss. The aim of the work is to show how these processes can be connected and the heat received from one adsorber is transported to another adsorber. As part of the study, the heat and mass recovery processes will be considered. It turns out that in the thermal wave type systems, it is possible to recover more than 25% of the energy lost to bring the adsorber to the states in which they will operate efficiently to desorb and adsorb refrigerant. That is, it is possible to improve the efficiency of the adsorption refrigeration unit using the proposed improvements.

scholarly journals Experimental Study On Thermal Wave Type Adsorption Refrigeration System Working On A Pair Of Activated Carbon And Methanol

2015 ◽  
Vol 36 (4) ◽  
pp. 395-404 ◽  
Author(s):  
Andrzej Grzebielec ◽  
Artur Rusowicz ◽  
Rafał Laskowski
Keyword(s):  
Activated Carbon ◽  
Thermal Wave ◽  
Waste Heat ◽  
Coefficient Of Performance ◽  
Adsorption Refrigeration ◽  
Wave Type ◽  
Mode Of Operation ◽  
Thermal Oil ◽  
Solar Refrigeration ◽  
Storage Units

Abstract The aim of the study was to examine the efficiency of the thermal wave type adsorption refrigerating equipment working on a pair of activated carbon and methanol. Adsorption units can work in trigeneration systems and in applications driven by waste heat. They can be built also as a part of hybrid sorption-compressor systems, and they are very popular in solar refrigeration systems and energy storage units. The device examined in this study operates in a special mode called thermal wave. This mode allows to achieve higher efficiency rates than the normal mode of operation, as a significant contributor to transport heat from one to the other adsorber. To carry out the experiment a test bench was built, consisting of two cylindrical adsorbers filled with activated carbon, condenser, evaporator, oil heater and two oil coolers. Thermal oil circulation was responsible for providing and receiving heat from adsorbers. In order to perform the correct action a special control algorithm device was developed and implemented to keep the temperature in the evaporator at a preset level. The experimental results show the operating parameters changes in both adsorbers. Obtained COP (coefficient of performance) for the cycle was 0.13.

scholarly journals Indirect controllability of locally coupled wave-type systems and applications

2013 ◽  
Vol 99 (5) ◽  
pp. 544-576 ◽  
Author(s):  
Fatiha Alabau-Boussouira ◽  
Matthieu Léautaud
Keyword(s):  
Type Systems ◽  
Wave Type ◽  
Coupled Wave

Fluid turbulence simulations of divertor heat load for ITER hybrid scenario using BOUT++

2021 ◽  
Author(s):  
Xueyun Wang ◽  
Xueqiao Xu ◽  
Philip B Snyder ◽  
Zeyu Li
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Energy Loss ◽  
Heat Load ◽  
Type I ◽  
Fluid Turbulence ◽  
Drift Model ◽  
Steady State Operation ◽  
Different Types ◽  
The One

Abstract The BOUT++ six-field turbulence code is used to simulate the ITER 11.5MA hybrid scenario and a brief comparison is made among ITER baseline, hybrid and steady-state operation (SSO) scenarios. Peeling-ballooning instabilities with different toroidal mode numbers dominate in different scenarios and consequently yield different types of ELMs. The energy loss fractions (ΔWped/Wped) caused by unmitigated ELMs in the baseline and hybrid scenarios are large (~2%) while the one in the SSO scenario is dramatically smaller (~1%), which are consistent with the features of type-I ELMs and grassy ELMs respectively. The intra ELM divertor heat flux width in the three scenarios given by the simulations is larger than the estimations for inter ELM phase based on Goldston’s heuristic drift model. The toroidal gap edge melting limit of tungsten monoblocks of divertor targets imposes constraints on ELM energy loss, giving that the ELM energy loss fraction should be smaller than 0.4%, 1.0%, and 1.2% for ITER baseline, hybrid and SSO scenarios, correspondingly. The simulation shows that only the SSO scenario with grassy ELMs may satisfy the constraint.

Brewer’s spent grains as biofuels in combustion-based energy recovery processes: Evaluation of thermo-oxidative decomposition

Fuel ◽  
2022 ◽  
Vol 312 ◽  
pp. 122955
Author(s):  
O. Gil-Castell ◽  
N. Mascia ◽  
C. Primaz ◽  
F. Vásqez-Garay ◽  
M.G. Baschetti ◽  
...  
Keyword(s):  
Energy Recovery ◽  
Oxidative Decomposition ◽  
Recovery Processes ◽  
Spent Grains

Performance Improvement of Membrane Energy Exchanger using Ultrasound for HVAC Application

2021 ◽  
pp. 1-29
Author(s):  
Gurubalan Annadurai ◽  
Maiya M.P. ◽  
Patrick Geoghegan ◽  
Carey Simonson
Keyword(s):  
Air Conditioning ◽  
Energy Recovery ◽  
Mass Transfer Process ◽  
Porous Membrane ◽  
Air Conditioning System ◽  
Energy Saving Potential ◽  
Recovery Processes ◽  
Additional Resistance ◽  
Membrane Energy ◽  
Ac Systems

Abstract Air conditioning (AC) systems consume the maximum proportion of the total electricity used in the building sector. The demand of AC systems is expected to increase exponentially in the coming years due to various reasons such as climate change, increasing affordability and increase in living floor space. Membrane-based liquid desiccant AC system along with energy recovery ventilating equipment is considered as a prospective alternative to the conventional air conditioning system (CACS) and has the potential to meet the increasing current and future AC demand in a sustainable manner. Its efficiency and energy saving potential with respect to CACS depends on the performance of the membrane-based dehumidifier, regenerator and energy recovery ventilating equipment which are commonly referred to as membrane energy exchangers (MEEs). MEE is an indirect exchanger type in which the working streams are separated by a porous membrane. This intermediate membrane creates an additional resistance for the heat and mass transfer process in the MEE. To reduce the resistance, this study experimentally and numerically investigates the influence of ultrasound on the performance of the MEE for dehumidification, humidification (applicable for membrane-based evaporative cooling and desiccant regeneration devices) and energy recovery processes. It is found that the vibration due to ultrasound has the potential to improve the effectiveness of the MEE by 55% in the dehumidification process and by 65% in the humidification and energy recovery processes.

scholarly journals Calculation algorithm for operating parameters of steam-compressive chilling machine with adsorptive chillling unit

2020 ◽  
Vol 8 (2) ◽  
pp. 3-9
Author(s):  
E.A. Belyanovskaya ◽  
◽  
G.M. Pustovoy ◽  
A.I. Sklyarenko ◽  
M.P. Sukhyy ◽  
...  
Keyword(s):  
Silica Gel ◽  
Thermal Energy ◽  
Sodium Acetate ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Coefficient Of Performance ◽  
Adsorptive Capacity ◽  
Operating Parameters ◽  
Adsorption Refrigeration ◽  
Refrigeration Unit

The work is focused on the development of an effective algorithm for calculating the operational characteristics of a steamcompressive chilling machine with an adsorptive chilling unit, which involves a cold box, an adsorber, an evaporator and a condenser, water being used as a refrigerant. An algorithm for calculating the operating parameters of the adsorptive chilling unit has been developed, which includes the determination of the cooling capacity of the steam compressor refrigeration unit, the heat load on the condenser, the power consumed by the compressor, the coefficient of performance of the steam compressor refrigeration unit, as well as the calculation of the mass of water, the mass of the adsorbent, the refrigerating capacity, the coefficient of performance of the adsorptive chilling unit and the coefficient of useful energy utilization of a steam compressive chilling machine with an adsorption chilling unit. The chilling capacity and the coefficient of performance of the adsorption chilling unit are estimated under the operating conditions of a typical steam compression chilling machine. The crucial factors affecting the efficiency of the adsorptive chilling unit are analyzed. It has been established that the chilling capacity, the coefficient of performance of the adsorption refrigeration module and the energy efficiency of the installation are determined by the thermal load on the condenser, and, therefore, by the mass of water that is desorbed and evaporated. The coefficient of performance of the adsorption chilling unit and the efficiency of the steam compressor chilling machine with the adsorptive chilling unit are estimated to be 0.878 and 4.64. The criteria for the selection of adsorbents for the adsorption module are analyzed. The temperature of regeneration is determined by the temperatures in the condenser, and the limit adsorption affects the mass of the adsorbent and the size of the adsorber. A comparison of the efficiency of adsorptive chi l l ing uni t based on silicoaluminophosphates and composite adsorbents «silica gel – sodium acetate» is carried out. The prospects of using composites «silica gel – СН3СООNa» are shown. The optimal composition of the composite was established, which corresponds to the minimal size of the adsorber, (80% sodium acetate and 20% silica gel). The prospects of using adsorptive conversion of thermal energy for utilization of low-potential thermal energy during the operation of steam compressive chilling machine are shown. Keywords: adsorptive conversion of heat energy, composite adsorbent, steam compressive chilling unit, adsorption, adsorptive capacity.

The effect of boundaries on wave propagation in a liquid-filled porous solid: VI. Love waves in a double surface layer

1964 ◽  
Vol 54 (1) ◽  
pp. 417-423
Author(s):  
H. Deresiewicz
Keyword(s):  
Wave Propagation ◽  
Surface Layer ◽  
Dispersion Relation ◽  
Energy Loss ◽  
Classical Solution ◽  
Specific Energy ◽  
Classical Case ◽  
Specific Energy Loss ◽  
Double Surface ◽  
The One

abstract The classical solution of Stoneley and Tillotson is generalized by considering the outer one of the pair of layers to be porous. Although the dispersion relation turns out, for practical purposes, to be identical with the one governing the classical case, the motion in the present instance is shown to be dissipative and the expression is exhibited for the specific energy loss.

Comparison of an Adsorption Refrigeration Unit Operating with Two and Four Adsorbers

2017 ◽  
Author(s):  
Andrzej Grzebielec
Keyword(s):  
Cooling Capacity ◽  
Adsorption Refrigeration ◽  
Entire Process ◽  
Refrigeration Unit ◽  
Operating Unit ◽  
Over Time

Adsorption refrigeration systems can be built with one, two or more adsorbers. The most common devices are built of two adsorbers. This fact makes the achieved cooling capacity is variable over time, and in some periods of operation is even 0 kW. Increased number of adsorbers causes the cooling capacity obtained in time is more balanced. The aim of the study is to compare the most popular operating unit with two adsorbers with the installation which continuously work with four adsorbers. It turns out that such a solution can align cooling capacity during the entire process. This solution does not affect the effectiveness of the device, but only on its size. Absorbers are the largest part of the device. So this type of solution is dedicated to wherever it is needed fluently providing cooling capacity and there is no possibility of collecting cooling in tanks.

Effects of Frictional Loss on Bicycle Chain Drive Efficiency

1999 ◽  
Vol 123 (4) ◽  
pp. 598-605 ◽  
Author(s):  
James B. Spicer ◽  
Christopher J. K. Richardson ◽  
Michael J. Ehrlich ◽  
Johanna R. Bernstein ◽  
Masahiko Fukuda ◽  
...  
Keyword(s):  
Energy Loss ◽  
Type Systems ◽  
Mechanical Efficiency ◽  
Chain Drive ◽  
Frictional Loss ◽  
Infrared Measurements ◽  
Drive Trains ◽  
Chain Drives ◽  
Lubrication Conditions ◽  
Loss Mechanisms

Chain drive efficiency has been studied to understand energy loss mechanisms in bicycle drive trains, primarily for derailleur-type systems. An analytical study of frictional energy loss mechanisms for chain drives is given along with a series of experimental measurements of chain drive efficiency under a range of power, speed and lubrication conditions. Measurements of mechanical efficiency are compared to infrared measurements indicating that frictional losses cannot account for the observed variations in efficiency. The results of this study indicate that chain tension and sprocket size primarily affect efficiency and that non-thermal loss mechanisms dominate overall chain drive efficiency.

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