Increase of energy efficiency ratio of a direct evaporative cooler by dynamic behavior with energy and exergy analysis

2021 ◽  
pp. 095440622110420
Author(s):  
Behzad Omidi Kashani
Keyword(s):  
Energy Efficiency ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Dynamic State ◽  
Circulation Rate ◽  
Cooling Load ◽  
Efficiency Ratio ◽  
Static State ◽  
Circulation Pump ◽  
Water Rate

The present research is about increasing the energy efficiency ratio (EER) in current direct evaporative coolers (DEC) in Iran. Increasing the cooling load and reducing the electrical energy consumption simultaneously (increasing the energy efficiency ratio (EER)) in DEC are the main goals of manufacturers and consumers of this device. When the circulation water pump runs continuously (static state), the circulation water rate is about 1.89 to 2.90 times of the amounts recommended in the reasonable standards. In order to adjust the circulation water rate to the recommended amount by standards, the present study has utilized repetitive cyclic scheduling programs to reduce the circulation rate to the optimal amount, (by turning the circulation pump on and off by dynamic pattern operation). In other words, the circulation pump stays on only for a certain period of a working cycle, and then the pump stays off for the rest of it. The cooling load and EER were measured based on ASHRAE 133 (2015). The results indicated that the cooling load in the dynamic state increased by 5.03 and 6.18 percent compared to the static state at low and high fan speeds, respectively. Moreover, in comparison with the static state, the amount of electrical energy consumed (kW-hr) in the dynamic state decreased by 8.8 and 4.2 percent at low and high fan speeds, respectively. Finally, the coefficient of performance (COP or EER) of the DEC in the dynamic state is increased by 15.16 and 10.78 in comparison with the static state at low and high fan speeds, respectively.

USING WATER VAPOR AS REFRIGERANT IN MULTISTAGE VARIABLE SPEED TURBO COMPRESSOR TO IMPROVE SEASONAL ENERGY EFFICIENCY RATIO OF AIR CONDITIONING

2011 ◽  
Vol 19 (02) ◽  
pp. 131-140
Author(s):  
QUBO LI ◽  
DEMISS A. AMIBE ◽  
NORBERT MÜLLER
Keyword(s):  
Energy Efficiency ◽  
Water Vapor ◽  
Energy Demand ◽  
Air Conditioning ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Air Conditioner ◽  
Variable Speed ◽  
Efficiency Ratio ◽  
Part Load

An air conditioning system using water as refrigerant (R718) that compresses water vapor with multistage stage variable speed axial compressor with intercooling between stages by water injection is considered. Four stage compression with flash intercooling resulted in 50% improvement of coefficient of performance (COP) at full load compared to conventional refrigerants like R134a. The energy efficiency of an air conditioning unit is specified by seasonal energy efficiency ratio (SEER). SEER is defined as the ratio of cooling output of an air conditioner measured and electrical energy consumption as per AHRI 210/240 during cooling season. The SEER is computed after determining the evaporator cooling capacity and the electrical energy demand of the compressor at each bin temperature using assumed compressor isentropic efficiency, mechanical efficiency and electrical efficiency and multiplying by the weight of each bin temperature to determine the total for the cooling season. As a result of multistage compression, best part load performance of water as a refrigerant and operation of compressor near design point at part load due to variable speed drive, 50%–60% improvement in SEER is obtained compared to the best available in the market using conventional refrigerants such as R134a with single stage compression.

Multi Stage Variable Speed Turbo Compressor for Enhancing Seasonal Energy Efficiency Ratio of Air Conditioners Using R718 as Refrigerant

2010 ◽  
Author(s):  
Demiss A. Amibe ◽  
Qubo Li ◽  
Norbert Mu¨ller
Keyword(s):  
Energy Efficiency ◽  
Energy Demand ◽  
Air Conditioning ◽  
Water Injection ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Air Conditioner ◽  
Variable Speed ◽  
Efficiency Ratio ◽  
Part Load

An air conditioning system using water as refrigerant (R718) that compresses water vapor with multistage stage variable speed axial compressor with intercooling between stages by water injection is considered. Four stage compression with flash intercooling resulted in 50% improvement of coefficient of performance (COP) at full load compared to conventional refrigerants like R134a. The energy-efficiency of an air conditioning unit is specified by seasonal energy efficiency ratio (SEER). SEER is defined as the ratio of cooling output of an air conditioner measured and electrical energy consumption as per AHRI 210/240 during cooling season. The SEER is computed after determining the evaporator cooling capacity and the electrical energy demand of the compressor at each bin temperature using assumed compressor isentropic efficiency, mechanical efficiency and electrical efficiency and multiplying by the weight of each bin temperature to determine the total for the cooling season. As a result of multistage compression, best part load performance of water as a refrigerant and operation of compressor near design point at part load due to variable speed drive, 50–60% improvement in SEER is obtained compared to the best available in the market using conventional refrigerants such as R134a with single stage compression.

scholarly journals Exploratory Research to Improve Energy-Efficiency of a Ground-Coupled Heat Pump Utilizing an Automatic Control Device of Circulation Pump Speed

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5016
Author(s):  
Ioan Sarbu ◽  
Calin Sebarchievici
Keyword(s):  
Energy Efficiency ◽  
Simulation Model ◽  
Heat Pump ◽  
Co2 Emission ◽  
Air Conditioning ◽  
Coefficient Of Performance ◽  
Exploratory Research ◽  
Circulation Pump ◽  
Pump Speed ◽  
Heat Pump Unit

Ground-coupled heat pumps (GCHPs) are an efficient thermal energy production system that can satisfy the gap between heating and air-conditioning. Be that as it may, exploratory research on GCHPs is still lacking. The first objective of this article is to describe a utilitarian energy-efficiency improvement device for a vertical GCHP system that includes a buffer tank (BT) between the heat pump unit and the fan coil units and user supply, utilizing the quantitative regulation of water flow rate with a variable-speed circulation pump. At that point, the investigative estimations are utilized to test the performances of the GCHP system in various operating modes. Fundamental efficiency parameters (coefficient of performance (COP) and CO2 emission) are achieved for one month of running utilizing two control strategies of the GCHP—standard and optimized regulation of the water pump speed—and a benchmarking of these parameters is achieved. Exploratory research has indicated higher efficiency of the system for the flow regulation solution utilizing a BT and programmed control equipment for the circulation pump speed compared with the standard regulation solution (COPsys with 7–8% higher and CO2 emission level 7.5–8% lower). The second objective is to elaborate a simulation model of the necessary heat/cold in heating and air-conditioning periods, utilizing the Transient Systems Simulation (TRNSYS) program. Finally, the simulation, acquired utilizing the TRNSYS program, is analyzed and compared with experimental information, leading to a good agreement and, along these lines, the simulation model is approved.

Retrofitting R-22 Split Type Air Conditioning with Hydrocarbon (HCR-22) Refrigerant

2013 ◽  
Vol 388 ◽  
pp. 91-95 ◽  
Author(s):  
Henry Nasution ◽  
Abdul Latiff Zulkarnain ◽  
Azhar Abdul Aziz ◽  
Mohd Rozi Mohd Perang
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Room Temperature ◽  
Internal Heat ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Refrigeration System ◽  
Electrical Energy Consumption ◽  
The One

An experimental study to evaluate the energy consumption of a split type air conditioning is presented. The compressor works with the fluids R-22 and HCR-22 and has been tested varying the internal heat load 0, 500, 700 and 1000 W. The measurements taken during the one hour experimental periods at 10-minutes interval times for temperature setpoint of 20oC. The performance data considered where the evaporator cooling load, the condenser heat rejection, the electrical energy consumption, the refrigeration system temperatures, and the room temperature. And hence the Coefficient of Performance (COP) could be determined. The final results of this study show an overall better energy consumption of the HFC-22 compared with the R-22.

scholarly journals DESIGN AND ANALYSIS OF THERMAL SHOWCASE MINI AS A BEVERAGE COOLER USING A THERMOELECTRIC MODULE

2021 ◽  
Vol 4 (01) ◽  
pp. 14-22
Author(s):  
Muhammad Helmy
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Thermoelectric Module ◽  
Solid Material ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Home Office ◽  
Conduction Heat Transfer ◽  
Cold Energy

In Indonesia, which has a tropical climate, a beverage cooler is needed. Almost every home, office, company, supermarket, and mall has installed beverage coolers. This has become a major necessity for people living in tropical countries. Especially those who live in eastern Indonesia, such as Ambon, NTT, and Papua, which have very hot temperatures. There are various types of use of the thermoelectric or peltier module, including food coolers, medicinal coolers, drinking water coolers in dispensers, and computer processor coolers. Besides being easy to apply, this tool is expected to be able to open up ideas in the use of thermoelectric modules that are more environmentally friendly than refrigerants. This research was conducted to obtain the size of the showcase mini design, the assembly process of the showcase mini tool, and to obtain the thermal analysis results contained in the showcase mini tool as a cooling medium. Showcase is a refrigerator that is used to display food or drinks that you want to display using glass media as a standout for the product being displayed. Thermoelectric technology is a technology that works by converting heat energy into electrical energy directly or vice versa, from electrical energy to produce cold energy. Thermoelectric is made of solid state material (solid material) which can convert energy from temperature difference to potential difference or vice versa. In this study, 2 variations of cooling load were used, namely without cooling load and with cooling load. Thermal analysis was carried out and got the results. The highest result from the calculation of conduction heat transfer load without cooling load is 0.013 Watt. The highest result from the calculation of the conduction heat transfer load with the cooling load is 0.010 Watt. The highest result from calculating the product heat load is 1.555 Watts. The highest result from the calculation of COP (Coefficient Of Performance) is 4,823. The expenses incurred each month are 16,000 rupiah.

scholarly journals Energy Assessment of Sorghum Cultivation in Southern Ukraine

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 695
Author(s):  
Oleg Bazaluk ◽  
Valerii Havrysh ◽  
Mykhailo Fedorchuk ◽  
Vitalii Nitsenko
Keyword(s):  
Energy Efficiency ◽  
Total Energy ◽  
Climate Changes ◽  
Field Experiments ◽  
Renewable Energy Sources ◽  
Grain Sorghum ◽  
Mineral Fertilizers ◽  
Efficiency Ratio ◽  
Energy Inputs ◽  
Southern Ukraine

Global climate changes and fossil fuel reserve depletion are drivers for the search for environmentally friendly renewable energy sources. In Europe, biomass represents the main alternative to fossil fuels. Among energy crops, sorghum is a promising crop for arid regions. The biomass yield and energy efficiency of sorghum (both silage and grain) were studied based on field experiments conducted in Southern Ukraine. The following climate changes were identified: an increase in temperature and a decrease in precipitation. The total energy inputs for sweet sorghum were estimated at 11.256 GJ/ha. The main contributors to the energy inputs are mineral fertilizers (56.99%). The experiment showed that a yield of 40.6 t/ha could be achieved with annual precipitation of 350 mm. The energy efficiency ratio was determined to be 11.18. The total energy inputs for grain sorghum was 16.081 GJ/ha. Its yield (grain) varied from 1.92 to 7.05 t/ha. The energy efficiency ratio of grain sorghum ranged from 2.8 to 16.7.

scholarly journals Water Extraction from Air: A Proposal for a New Indicator to Compare Air Water Generators Efficiency

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 224
Author(s):  
Lucia Cattani ◽  
Anna Magrini ◽  
Paolo Cattani
Keyword(s):  
Energy Efficiency ◽  
Comprehensive Evaluation ◽  
Specific Energy Consumption ◽  
Energy Performance ◽  
Water Extraction ◽  
Coefficient Of Performance ◽  
Efficiency Evaluation ◽  
Evaluation Approach ◽  
Cycle Systems ◽  
Definition Of

Water extraction from air, based on reverse cycle systems, is becoming a technology more and more diffused and various models of air to water generators (AWG) are now available, all claiming the best efficiency. To date, there is not a standard indicator stating energy efficiency for AWGs, neither in the literature nor in technical practice. The only evaluation parameter, that can be found is a sort of specific energy consumption (SEC) without any clear indications about the involved calculation terms, definition of hypotheses, or environmental conditions. The current work is a first proposal of an indicator to standardise the AWG efficiency evaluation. The indicator is called WET (Water Energy Transformation); it states water production as a useful effect of an AWG machine and calculates its energy performance with an approach similar to COP (Coefficient of Performance) and EER (Energy Efficiency Ratio) evaluation. The indicator is meant to be a normalised tool that permits comparing different AWG machines, but it is also the first part of a wider study, currently under development that is oriented to obtain a global index formulation that combines WET itself, EER and COP, and it is intended for a comprehensive evaluation of all the useful effects of a reverse cycle in integrated machines, in compliance with the current efficiency evaluation approach. The current paper presents the WET equation, with a discussion about involved terms, a set of normalised calculation conditions and some application examples, including a comparison with SEC.

scholarly journals Specific Electrical Energy Consumption and CO2 Emissions Assessment of Agrifood Industries in the Central Region of Portugal

2014 ◽  
Vol 675-677 ◽  
pp. 1880-1886 ◽  
Author(s):  
Pedro D. Silva ◽  
Pedro Dinis Gaspar ◽  
J. Nunes ◽  
L.P.A Andrade
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Food Safety ◽  
Central Region ◽  
Electrical Energy ◽  
Electrical Energy Consumption ◽  
Reference Levels ◽  
Energy Characteristics ◽  
Result Analysis

This paper provides a characterization of the electrical energy consumption of agrifood industries located in the central region of Portugal that use refrigeration systems to ensure the food safety. The study is based on the result analysis of survey data and energy characteristics of the participating companies belonging to the following agrifood sectors: meat, dairy, horticultural, distribution and wine. Through the quantification of energy consumption of companies is possible to determine the amount of greenhouse gases (GHGs) emissions indexed to its manufacturing process. Comparing the energy and GHGs emissions indexes of companies of a sector and between sectors is possible to create reference levels. With the results of this work is possible to rating the companies in relation to reference levels of energy and GHGs emissions and thus promote the rational use of energy by the application of practice measures for the improvement of the energy efficiency and the reduction of GHGs emissions.

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