Dynamic Simulation of an Ejector-Based Cooling System for Residential Solar Air-Conditioning

2012 ◽  
Author(s):  
Stefano Gavioli ◽  
Jean-Marie Seynhaeve ◽  
Yann Bartosiewicz
Keyword(s):  
Dynamic Simulation ◽  
Air Conditioning ◽  
Cooling System ◽  
Geographic Location ◽  
Hot Water ◽  
Cooling Power ◽  
Dynamic Simulation Model ◽  
Hot Season ◽  
Transient Thermal ◽  
Ejector Cycle

A smart and sustainable way to produce cooling power during the hot season is through thermal activated compression. One of the most promising technology is the ejector cycle. An experimental machine based on this technology has been designed and built at Université Catholique de Louvain (UCL). This study presents a dynamic simulation model of a full house incorporating solar collectors to produce domestic hot water and to feed an ejector-based solar air-conditioning machine. The model takes into account geographic location, transient thermal house behaviour, and also integrates a performance map of the ejector cycle based on real measurement campaign. Different types of collectors and storage sizes have been studied as well. In this paper, the developed model is used to analyze and optimize operation and strategy of hot water production and air conditioning. Results show that the full solar solution may cover low energy house needs.

The Analysis of Modifications in Cooling Systems for High-Performance Data Centers. A Case Study

2017 ◽  
Author(s):  
Artur Rusowicz ◽  
Adam Ruciński ◽  
Rafał Laskowski
Keyword(s):  
Air Conditioning ◽  
High Performance ◽  
Energy Savings ◽  
Cooling System ◽  
Capital Expenditure ◽  
Cooling Power ◽  
Power Demand ◽  
Excessive Heat ◽  
Refrigeration Equipment ◽  
Payback Time

One of main issues concerning server room operation is appropriate cooling of electronic modules to prevent excessive heat generation resulting in their damage. Since high cooling powers are required, precision air conditioning systems are used that are specially designed for cooling server and equipment rooms, server cabinets, etc. These devices require very large energy supplies. The paper proposes an upgrade of a cooling system for three server rooms in which refrigeration equipment with a cooling power of 1.873 MW is installed. The average actual cooling power demand is 890 kW, and some units work as a standby. Thir-eight direct-evaporation air-conditioning cabinets are installed. The refrigerant is R407C. The devices have been operated for 14 years; therefore, the refrigeration equipment should be replaced with modern units. The paper compares three approaches: replacing the units with similar ones based on newer technology, introducing contained aisle configurations of rack cabinets and units based on newer technology with additional EconoPhase modules. The application of free cooling was not analyzed since mounting additional heat exchangers was impossible (due to the lack of space and limited roof loading capacity). The paper provides capital and operating costs of the solutions. The introduction of up-to-date units and replacing condensers resulted in lowering the electric power demand by 16%. The simple payback time (SPBT) of this solution is 18.8 years. The energy savings achieved through the second solution (contained aisle configurations of rack cabinets) amount to 37.8%, with SPBT equal to 8.38 years. Variant III, consisting in using modern units with additional EconoPhase modules, significantly improves energy savings (48.3%) but it requires large capital expenditure, with simple payback time of 12.1 years.

Simulation and performance study of a two-bed adsorption cooling system operated with activated carbon-ethanol

2021 ◽  
pp. 095440622110420
Author(s):  
V Baiju ◽  
A Asif Sha ◽  
NK Mohammed Sajid ◽  
K Muhammedali Shafeeque
Keyword(s):  
Water Temperature ◽  
Performance Optimization ◽  
Cooling System ◽  
Cooling Water ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Performance Study ◽  
Evaporator Temperature ◽  
Adsorption Cooling System

This paper presents the transient model of a two-bed adsorption cooling system performed in the SIMULINK platform. The inlet chilled water temperature in the evaporator, temperature of cooling water and hot water temperature of the adsorbent bed and its effect on systems coefficient of performance, refrigeration effect and specific cooling power have been studied and presented. It is observed that the systems coefficient of performance is 0.57 when the inlet hot water temperature about 80 °C. In this study, the optimum cooling power and systems coefficient of performance are also determined in terms of the phase time, shifting duration and hot water inflow temperature. The results indicates that the cooling water and hot water inlet temperatures significantly affects the coefficient of performance, specific cooling power and cooling power of the system. The effect of mass flow rate on the cooler efficiency is also presented. A two bed adsorption system of capacity 13.5 kW having an evaporator and condenser temperatures of 6°C and 28°C, respectively, are considered for the present investigation. The adsorbent mass considered is 45 kg with a shifting duration of 20 sec. The result of this study gives the basis for performance optimization of a practical continuous operating vapour adsorption cooler.

Dynamic Analysis on Energy-Saving Effect of Distributed Cooling System in TBS

2014 ◽  
Vol 472 ◽  
pp. 1047-1051
Author(s):  
Tian Jian Yang ◽  
Yang Li
Keyword(s):  
Dynamic Analysis ◽  
Energy Saving ◽  
Dynamic Simulation ◽  
Heat Balance ◽  
Air Conditioning ◽  
Cooling System ◽  
Balance Model ◽  
Saving Effect ◽  
The Heat Balance

In order to evaluate the energy-saving effect of Distributed Cooling System (DCS) analytically, the heat balance model of DCS in a TBS is established and then dynamic simulation is employed. The numeral results show that DCS has much better energy-saving effect than traditional air conditioning (AC) and the energy-saving effect is steady all year round.

Solar Assisted Desiccant Cooling Simulation for Different Climate Zones

2011 ◽  
Author(s):  
Wendell Concina ◽  
Suresh Sadineni ◽  
Robert Boehm
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Evaporative Cooling ◽  
The United States ◽  
Economic Benefits ◽  
Climatic Conditions ◽  
Hot Water ◽  
Low Grade ◽  
Cooling Systems ◽  
Climate Zones

Evaporative cooling is among the most cost effective methods of air conditioning, but is less efficient in humid climates. An evaporative system coupled with a desiccant wheel can operate effectively in broader climatic conditions. These cooling systems can substitute traditional vapor compression air conditioning systems as they involve environmentally friendly cooling processes with reduced electricity demand (which is commonly generated from fossil fuels) along with no harmful CFC based refrigerant usage. Furthermore, direct utilization of low grade energy sources such as solar thermal energy or flue gas heat can drive the desiccant regeneration process, thus providing economic benefits. This study presents the results of simulations of desiccant cooling system performance for different climate zones of the United States. Solar assisted desiccant air conditioning is particularly useful where there are abundant solar resources with high temperature and humidity levels. Building energy simulations determined cooling energy requirements for the building. Simulation of an evacuated solar hot water collector model provided the heat energy available for regeneration of the desiccant. Solid desiccant of common material such as silica gel used in a rotary wheel is simulated using established validated computer models; this is coupled with evaporative cooling. Transients of the overall system for different cooling loads and solar radiation levels are presented. Finally, feasibility studies of the desiccant cooling systems are presented in comparison with traditional cooling system. Further analysis of the data presents optimization opportunities. Energy savings were achieved in all climatic conditions with decreased effectiveness in more humid conditions.

scholarly journals Performance Evaluation of Photovoltaic Solar Air Conditioning

2016 ◽  
Vol 53 (6) ◽  
pp. 29-36
Author(s):  
A. Snegirjovs ◽  
P. Shipkovs ◽  
K. Lebedeva ◽  
G. Kashkarova ◽  
L. Migla ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Air Conditioning ◽  
Large Scale ◽  
Ambient Air ◽  
Hot Water ◽  
Energy Output ◽  
Cooling Power ◽  
Energy Unit ◽  
Technical Data ◽  
Reverse Mode

Abstract Information on the electrical-driven solar air conditioning (SAC) is rather scanty. A considerable body of technical data mostly concerns large-scale photo-voltaic solar air conditioning (PV-SAC) systems. Reliable information about the energy output has arisen only in recent years; however, it is still not easily accessible, and sometimes its sources are closed. Despite these facts, solar energy researchers, observers and designers devote special attention to this type of SAC systems. In this study, performance evaluation is performed for the PV-SAC technology, in which low-power (up to 15 kWp of cooling power on average) systems are used. Such a system contains a PV electric-driven compression chiller with cold and heat sensible thermal storage capacities, and a rejected energy unit used for preheating domestic hot water (DHW). In a non-cooling season, it is possible to partly employ the system in the reverse mode for DHW production. In this mode, the ambient air serves as a heat source. Besides, free cooling is integrated in the PV-SAC concept.

scholarly journals Numerical Simulation and Validation of Thermoeletric Generator Based Self-Cooling System with Airflow

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4052 ◽  
Author(s):  
Cheng-Xian Lin ◽  
Robel Kiflemariam
Keyword(s):  
Cooling System ◽  
Electric Circuit ◽  
Cooling Power ◽  
Coupled Modeling ◽  
Power Characteristics ◽  
Spatially Distributed ◽  
Flow Heat ◽  
Transient Thermal ◽  
Comprehensive Framework ◽  
Density Results

In this paper, a general numerical methodology is developed and validated for the simulation of steady as well as transient thermal and electrical behaviors of thermoelectric generator (TEG)-based air flow self-cooling systems. The present model provides a comprehensive framework to advance the study of self-cooling applications by combining fluid flow, heat transfer and electric circuit simulations. The methodology is implemented by equation-based coupled modeling capabilities from multidisciplinary fields to capture the dynamic thermos-electric interaction in TEG elements, enabling the simulation of overall heating/cooling/power characteristics as well as spatially distributed thermal and flow fields in the entire device. Experiments have been conducted on two types of self-cooling arrangements to measure the device temperature, voltage and power produced by TEG modules. It was found that the computational model was able to predict the experimental results within 5% error. A parametric study was carried out using the validated model to study the effect of heat sink geometry and TEG arrangements on device temperature and power produced by the device. It was found that the power for self-cooling could be maximized by proper matching of the TEG modules to the fluid mover. Although an increase in fin density results in a rise in fan power consumption, a marked increase in net power and decreases in thermal resistance are observed.

Performance of an autonomous solar powered absorption air conditioning system

2015 ◽  
Vol 26 (1) ◽  
pp. 106-112
Author(s):  
Tatenda J. Bvumbe ◽  
Freddie L. Inambao
Keyword(s):  
System Performance ◽  
Air Conditioning ◽  
Cold Water ◽  
Cooling System ◽  
Water Storage ◽  
Performance Data ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Water Storage Tank ◽  
Average Value

The demand for air conditioning is increasing due to changing architectural trends and increased standards of living and indoor comfort conditions. Coupled to this, refrigerants used in conventional refrigeration systems have detrimental effects on the environment. As a result, there is an urgent need to implement environmentally cleaner ways of satisfying this air-conditioning demand. Absorption cooling systems have shown great potential to do so. In this study, system performance data for an autonomous solar heating and cooling system installed at the Vodafone Site System Innovation Centre, at the Vodacom Campus in Midrand was collected and analysed. The system comprises a 116 m2 vacuum tube collector array, a 6.5 m3 hot water storage tank, a 35 kW LiBr-Water absorption chiller, 1 m3 of cold water storage, a dry cooler for the chiller, and two underground thermal stores to pre-cool the supply air to the building and the dry cooler respectively. System performance data was collected from the beginning of December 2011 to the end of January 2012 and used to estimate the system long term performance. The chiller has an average coefficient of performance (COP) of 0.51 whilst the solar COP has an average value of 0.24. The total installation cost is R2 822 436.89, with an annuity of R225 949.75 and a cost per kWh of R28.88.

Modelling of a solar air conditioning pilot plant

2018 ◽  
Author(s):  
Sergio Lugo ◽  
Wilfrido Rivera
Keyword(s):  
Pilot Plant ◽  
Air Conditioning ◽  
Cooling System ◽  
Working Hours ◽  
Hot Water ◽  
Water Storage Tank ◽  
System A ◽  
Absorption Cooling ◽  
Transient System ◽  
Absorption Cooling System

"The present work repots the modelling of a solar air conditioning pilot plant to be installed in the Centro de Tecnología Avanzada (CIATEQ) in the city of Queretaro, México. The modelling was carried out by using the software Transient System Simulation Tool-16 (TRNSYS- 16). The pilot plant mainly consists of an absorption cooling system, a solar collector’s field, a hot water storage tank, a cooling tower and an air handler. The office of the CIATEQ were first modelling without an air conditioning unit and then with the proposed solar air conditioning pilot plant. The results showed that without air conditioning, temperatures higher than 28 ºC can be reached between the 12:00 and the 19:00 hours during spring and summer, while with the proposed pilot plant temperatures not higher than 25 ºC can be obtained during the whole year during the working hours."

Cost and Performance Analysis of a Solar Thermal Cooling Project

2010 ◽  
Author(s):  
Joel K. Dickinson ◽  
Robert O. Hess ◽  
Jeff Seaton ◽  
Henny van Lambalgen ◽  
Andrea L. Burnham
Keyword(s):  
Performance Analysis ◽  
Air Conditioning ◽  
Cooling System ◽  
Hot Water ◽  
Solar Thermal ◽  
Maintenance Cost ◽  
Conditioning Equipment ◽  
And Performance ◽  
Solar Thermal Cooling ◽  
Thermal Cooling

This paper presents the findings of a field study and performance analysis of a solar thermal cooling system located in Phoenix, Arizona. This system is compared to conventional air conditioning equipment, as well as conventional air conditioning equipment powered by solar electric (photovoltaics). The design of the solar cooling system, which incorporates solar-generated hot water and a single-stage absorption chiller, is discussed. Capital and maintenance cost estimates, including auxiliary electric load and water, are also provided. Operational problems are reviewed together with the design modifications that were required to resolve these issues. Performance of the system and the individual components was determined based on field data collected. Using this data the solar cooler energy savings over conventional air conditioning equipment was determined (Figure 1).

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