Influence of Outside Temperature on the Operation of the Adsorption Chiller

2017 ◽  
Author(s):  
Andrzej Grzebielec ◽  
Rafał Laskowski ◽  
Adam Ruciński
Keyword(s):  
Waste Heat ◽  
Experimental Studies ◽  
Coefficient Of Performance ◽  
External Parameter ◽  
Adsorption Refrigeration ◽  
Adsorption Chiller ◽  
Type Device ◽  
Lower Temperature

Adsorption refrigeration systems are characterized by a lower coefficient of performance than the compressor type device or even absorption, but can utilize waste heat at lower temperature. The aim of the study was to determine which external parameter has the greatest impact on the efficiency of the adsorption device. As a result of experimental studies there was found that this is not the temperature of the feed but particularly the temperature of external air. For this reason, it is recommended that the adsorption device should cooperate with evaporative spray coolers, instead of with popular dry coolers. This solution will increase annual efficiency of adsorption unit approx. by 25% and significantly reduce the costs of cold generation.

Two-Stage Non-Regenerative Silica Gel-Water Adsorption Refrigeration Cycle

2000 ◽  
Author(s):  
B. B. Saha ◽  
K. C. A. Alam ◽  
A. Akisawa ◽  
T. Kashiwagi ◽  
K. C. Ng ◽  
...  
Keyword(s):  
Heat Pump ◽  
Silica Gel ◽  
Water Adsorption ◽  
Waste Heat ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Adsorption Refrigeration ◽  
Two Stage ◽  
Adsorption Chiller ◽  
Adsorption Heat Pump

Abstract Over the past two decades there have been considerable efforts to use adsorption (solid/vapor) for cooling and heat pump applications, but intensified efforts were initiated only since the imposition of international restrictions on the production and use of CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons). Closed-type, conventional adsorption refrigeration and heat pump systems have an increasing market share in Japan. In this paper, a two-stage non-regenerative, silica gel-water adsorption chiller design is outlined. Experimental measurements are performed on a prototype of a 3.5 kW rated cooling capacity adsorption heat pump in order to determine its performance under different operating temperatures (hot, cooling and chilled water). The chiller performance is analyzed in terms of cooling capacity and coefficient of performance (COP). The main innovative feature in the two-stage adsorption chiller is the ability to utilize low-temperature waste heat (∼55°C) as the driving source with a cooling source of 30°C. The technological difficulty inherent in operating a thermally activated cycle with such a small regenerating temperature lift (temperature difference between heat source and heat sink inlets) is overcome by use of a two-stage cycle.

scholarly journals Using adsorption chillers for utilising waste heat from power plants

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1143-1151 ◽  
Author(s):  
Karol Sztekler ◽  
Wojciech Kalawa ◽  
Sebastian Stefanski ◽  
Jaroslaw Krzywanski ◽  
Karolina Grabowska ◽  
...  
Keyword(s):  
Power Generation ◽  
Energy Efficiency ◽  
Power Plant ◽  
Power Plants ◽  
Waste Heat ◽  
Primary Energy ◽  
Simulation Software ◽  
Coefficient Of Performance ◽  
Low Grade ◽  
Adsorption Chiller

At present, energy efficiency is a very important issue and it is power generation facilities, among others, that have to confront this challenge. The simultaneous production of electricity, heat and cooling, the so-called trigeneration, allows for substantial savings in the chemical energy of fuels. More efficient use of the primary energy contained in fuels translates into tangible earnings for power plants while reductions in the amounts of fuel burned, and of non-renewable resources in particular, certainly have a favorable impact on the natural environment. The main aim of the paper was to investigate the contribution of the use of adsorption chillers to improve the energy efficiency of a conventional power plant through the utilization of combined heat and power waste heat, involving the use of adsorption chillers. An adsorption chiller is an item of industrial equipment that is driven by low grade heat and intended to produce chilled water and desalinated water. Nowadays, adsorption chillers exhibit a low coefficient of performance. This type of plant is designed to increase the efficiency of the primary energy use. This objective as well as the conservation of non-renewable energy resources is becoming an increasingly important aspect of the operation of power generation facilities. As part of their project, the authors have modelled the cycle of a conventional heat power plant integrated with an adsorption chiller-based plant. Multi-variant simulation calculations were performed using IPSEpro simulation software.

scholarly journals Increasing the Performance of an Adsorption Chiller Operating in the Water Desalination Mode

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7743
Author(s):  
Karol Sztekler ◽  
Łukasz Mika
Keyword(s):  
Cycle Time ◽  
Waste Heat ◽  
Negative Impact ◽  
Saline Water ◽  
Water Desalination ◽  
Coefficient Of Performance ◽  
Solar Panels ◽  
Renewable Sources ◽  
Adsorption Chiller ◽  
Reduce Emissions

The intensive development of the world economy and the expected population growth mean that demand for cooling and water will continue to rise. The use of conventional technologies to meet this demand is associated with an enormous expenditure of electricity, which still comes mainly from non-renewable sources. With the increasing demand for energy, the increasing scarcity of drinking water, and the negative impact of humankind on the environment due to global warming and ozone depletion, intensive research has been carried out to find modern desalination technologies Most of the technologies use electricity for the process of desalination, and over 6% of the world’s electricity is generated from non-renewable sources, thus increasing the emissions of harmful pollutants into the atmosphere. One possibility to reduce emissions is the use of adsorption chillers with desalination function, which allow the production of cooling simultaneously with the process of water desalination. These systems can be powered by low-temperature waste heat from industrial processes or from renewable sources (solar panels) and require little electricity to operate. This paper presents options to improve their performance and increase the production of condensate in the process of desalination of saline water. Moreover, also presented are the results of tests carried out on a two-bed adsorption chiller with desalination function. The aim of the study was to determine the effect of cycle time on the cooling coefficient of performance (COP) and on the production of condensate from water desalination. The obtained results confirmed that increasing the adsorption and desorption cycle time leads to an increase in the COP value of the adsorption chiller, but the efficiency of the desalination process and condensate production decreases with increasing cycle time.

Performance Study of Waste Heat Driven Pressurized Adsorption Chiller

2013 ◽  
Vol 315 ◽  
pp. 380-384
Author(s):  
Khairul Habib
Keyword(s):  
Heat Source ◽  
Waste Heat ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Low Grade ◽  
Performance Study ◽  
Adsorption Chiller ◽  
And Performance ◽  
Low Grade Heat ◽  
Adsorption Desorption

This article presents a transient modeling and performance of a waste heat driven pressurized adsorption chiller. This innovative adsorption chiller employs pitch based activated carbon of type Maxsorb III as adsorbent and R507A as refrigerant as adsorbent-refrigerant pair. This chiller utilizes low-grade heat source to power the cycle. A parametric study has been presented where the effects of adsorption/desorption cycle time, switching time and regeneration temperature on the performance are reported in terms of cooling capacity and coefficient of performance (COP). Results indicate that the adsorption chiller is feasible even when low-temperature heat source is available.

scholarly journals Preliminary Results on Experimental Modelling of an Adsorption Chiller

2021 ◽  
Vol 6 ◽  
pp. 29
Author(s):  
Nayrana Daborer-Prado ◽  
Alois Resch
Keyword(s):  
Numerical Model ◽  
Water Cycle ◽  
Cooling System ◽  
Numerical Study ◽  
Lumped Parameter Model ◽  
Coefficient Of Performance ◽  
Adsorption Refrigeration ◽  
Experimental Modelling ◽  
Adsorption Chiller ◽  
Lumped Parameter

Adsorption refrigeration, as a renewable cooling method, has received more attention in the last few years. The interest in this technology comes especially from developing and tropical countries, where the demand for cooling increases every year due to economy and population growth. Based on this scenario, this work aims to develop a numerical model of an adsorption chiller driven with solar energy, which can be used to optimize the cooling system operation of the building where the device is situated and compare it with the current cooling methods in use. The numerical study here presented was created using Matlab/Simulink™, it is based on a lumped parameter model that relies on physical properties and represents a cooling system using a pair of silica gel-water in a two-bed chiller. In this study, the authors proposed a simplified version of the system and the numerical model, which aims to reduce the simulation time and provide faster results. Besides the temperatures in the system, which range from 52 °C to 72 °C in the hot cycle and 12 °C to 23 °C in the chilled water cycle, the results also include the variation of water uptake in the two adsorbent beds. In general, the simulated temperature, cooling and heating power and coefficient of performance (COP) are in fair agreement with the literature data, nevertheless, the final results show that improvements still have to be performed.

scholarly journals Simultaneous Optimization of Process Operational and Material Parameters for a 2-Bed Adsorption Refrigeration Process

2020 ◽  
Vol 4 (2) ◽  
pp. 31
Author(s):  
Marc Scherle ◽  
Ulrich Nieken
Keyword(s):  
Structural Material ◽  
Material Model ◽  
Heat Pumps ◽  
Simultaneous Optimization ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Operational Parameters ◽  
Adsorption Refrigeration ◽  
Adsorption Chiller ◽  
Material Parameters

In process engineering, optimization is usually carried out without the simultaneous consideration of material and process. This issue is addressed in the following contribution. A model-based optimization is presented to improve the performance of adsorption heat pumps. Optimization is carried out in two steps. First, we optimize the operational parameters, the cycle time, and the thickness of the adsorbent for a given adsorption material. In a second step we use a material model to predict heat and mass transfer and adsorption capacity from structural material parameters. This allows us to vary the structural material parameters and calculate the optimal operational parameters for each adsorbent. The two-step optimization thus identifies optimal material properties together with corresponding optimal operational parameters. As constraints, a minimum specific cooling power (SCP) and the passive mass of heat transfer pipes are used. The coefficient of performance (COP) is taken as the objective function. We exemplarily demonstrate the approach for a two-bed adsorption chiller, carbide-derived carbon as the adsorbent, methanol as the sorptive and boron-nitrate as additive to improve heat conductivity. The approach can be easily extended to multi-bed installations and more sophisticated material models.

scholarly journals Sustainable Cooling Research Using Activated Carbon Adsorbents and Their Environmental Impact

2017 ◽  
pp. 186-221 ◽  
Author(s):  
Ahmed M. Elsayed ◽  
Hassan J. Dakkama ◽  
Saad Mahmoud ◽  
Raya Al-Dadah ◽  
Waseem Kaialy
Keyword(s):  
Activated Carbon ◽  
Energy Consumption ◽  
Waste Heat ◽  
High Energy ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Adsorption Refrigeration ◽  
Recent Developments ◽  
Air Conditioning Systems ◽  
Vapour Compression

Conventional vapour compression system is one of the most utilized cycles in refrigeration and air conditioning systems, due to its compact size, the relatively low running cost, the high coefficient of performance and the wide range of the operating temperatures. Nevertheless, the system suffers from the high initial cost and the high-energy consumption. Unlike the vapour compression cycle, adsorption heat pumps have the advantage of utilizing waste heat reducing the energy consumption and the carbon emissions. Activated carbon is a porous adsorbent material that can be efficiently used in low temperature adsorption refrigeration systems. This chapter reviews the recent developments in the compact adsorption cooling systems using activated carbon regarding the enhancement of the material properties, the design of the sustainable adsorption systems and their environmental and cost perspectives.

Performance Study of Activated Carbon – Hydrofluoro Olefin Based Adsorption Cooling System

2013 ◽  
Vol 465-466 ◽  
pp. 206-210
Author(s):  
Khairul Habib
Keyword(s):  
Activated Carbon ◽  
Waste Heat ◽  
Cooling System ◽  
Combustion Engine ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Inlet Temperature ◽  
Performance Study ◽  
Adsorption Chiller

In this study, a dynamic behavior of a two bed adsorption chiller has been analyzed using highly porous activated carbon of type Maxsorb III as adsorbent and hydrofluoro olefin [R1234ze (E)] as refrigerant. R1234ze (E) has a low global warming potential (GWP) and zero ozone depletion potential (ODP). A parametric study has been presented where the effects of adsorption/desorption cycle time, cooling water inlet temperature and regeneration temperature on the performance are reported in terms of cooling capacity and coefficient of performance (COP). This chiller can be driven by the waste heat of internal combustion engine and hence it is applicable in automobile air conditioning.

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 Design and Thermodynamic Analysis of Waste Heat-Driven Zeolite–Water Continuous-Adsorption Refrigeration and Heat Pump System for Ships

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 699
Author(s):  
Cüneyt Ezgi
Keyword(s):  
Heat Pump ◽  
Waste Heat ◽  
Coefficient Of Performance ◽  
Substantial Contribution ◽  
Cooling Power ◽  
Cooling Mode ◽  
Adsorption Refrigeration ◽  
Pump System ◽  
Heat Pump System ◽  
Heat Pumping

Strict International Maritime Organization (IMO) rules enable ships to maximize fuel consumption and compliance with the climate. Cooling and heat-pumping technology powered by waste heat makes a substantial contribution to lowering ship gas emissions. This study explores, technically studies, and thermodynamically analyzes the efficiency of ongoing adsorption refrigeration and heating systems using a zeolite–water pair onboard a naval surface ship. An updated Dubin-in-Astakhov equation calculates the equilibrium adsorption potential of the operating pair used in the system. The coefficient of performance (COP) and specific cooling power (SCP)/specific heating power (SHP) values were between 0.109 and 0.384 and between 69.13 and 193.58 W kg−1 for cooling mode, and between 66.16 and 185.26 W kg−1 based on exhaust gas temperature and regeneration, respectively. Up to 27.64% and 52.91% met the cooling and heating load of the case vessel at a full load by the zeolite–water-adsorbed refrigeration/heat-pumping system. The COP of the heat pump and cooling systems was compared to that of adsorption cooling/heat pumps in the literature.

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