Energy, exergy and economic assessments of the dual-mode evaporative cooler for various international climate zones

2021 ◽  
pp. 014362442110449
Author(s):  
Sarvesh Kashyap ◽  
Jahar Sarkar ◽  
Amitesh Kumar
Keyword(s):  
Operating Cost ◽  
Cost Savings ◽  
Single Mode ◽  
Climatic Conditions ◽  
Coefficient Of Performance ◽  
Dual Mode ◽  
Climate Zones ◽  
Operating Modes ◽  
International Climate ◽  
Evaporative Cooler

The conventional desert cooler is effective for dry seasons and the regenerative evaporative cooler (REC) is an effective device for humid seasons in composite climate zones. Hence, the dual-mode evaporative cooler (a two-in-one device) is an intelligent choice for air conditioning, which can operate in both direct and regenerative modes depending on the seasonal climatic condition. The exergy and economic analyses of this novel device for global climatic conditions are performed to check the suitability in different regions of the world. An experimental prototype of a dual-mode evaporative cooler is developed and tested to validate the simulation model. The effectiveness, coefficient of performance, exergy destruction, exergy efficiency, operating cost, and specific total cost (STC) are evaluated for both (direct and regenerative) modes of operation. The annual and month-wise performances of dual-mode evaporative cooler have been assessed for five cities of international climate zones. The operating cost of both modes is compared by considering electricity charges in different countries. The dual-mode device is compared with the single-mode device as well. The specific cost is similar for both modes in most of the ASHRAE climatic zones. The present study reveals that significant energy and cost savings are possible by using the dual-mode evaporative cooler. Practical application: This article considers the application of a dual-mode evaporative cooler (direct as well as regenerative mode) in different climate zones and, through investigating the exergy and economic performances, allows designers and operators to understand the potential benefits of employing various operating modes in particular climates.

Seawater Scrubbing for the Removal of Sulfur Dioxide in a Steam Turbine Power Plant

2005 ◽  
Author(s):  
Akili D. Khawaji ◽  
Jong-Mihn Wie
Keyword(s):  
Power Plant ◽  
Sulfur Dioxide ◽  
Steam Turbine ◽  
Flue Gas ◽  
Operating Cost ◽  
Cooling Water ◽  
Cost Savings ◽  
Fuel Oil ◽  
So2 Emissions ◽  
Heavy Fuel Oil

The most popular method of controlling sulfur dioxide (SO2) emissions in a steam turbine power plant is a flue gas desulfurization (FGD) process that uses lime/limestone scrubbing. Another relatively newer FGD technology is to use seawater as a scrubbing medium to absorb SO2 by utilizing the alkalinity present in seawater. This seawater scrubbing FGD process is viable and attractive when a sufficient quantity of seawater is available as a spent cooling water within reasonable proximity to the FGD scrubber. In this process the SO2 gas in the flue gas is absorbed by seawater in an absorber and subsequently oxidized to sulfate by additional seawater. The benefits of the seawater FGD process over the lime/limestone process and other processes are; 1) The process does not require reagents for scrubbing as only seawater and air are needed, thereby reducing the plant operating cost significantly, and 2) No solid waste and sludge are generated, eliminating waste disposal, resulting in substantial cost savings and increasing plant operating reliability. This paper reviews the thermodynamic aspects of the SO2 and seawater system, basic process principles and chemistry, major unit operations consisting of absorption, oxidation and neutralization, plant operation and performance, cost estimates for a typical seawater FGD plant, and pertinent environmental issues and impacts. In addition, the paper presents the major design features of a seawater FGD scrubber for the 130 MW oil fired steam turbine power plant that is under construction in Madinat Yanbu Al-Sinaiyah, Saudi Arabia. The scrubber with the power plant designed for burning heavy fuel oil containing 4% sulfur by weight, is designed to reduce the SO2 level in flue gas to 425 ng/J from 1,957 ng/J.

The sensitivity of economic gains from high-speed planting

2017 ◽  
Vol 8 (2) ◽  
pp. 662-667
Author(s):  
C. R. Dillon ◽  
J. Shockley ◽  
T. Mark
Keyword(s):  
Optimization Model ◽  
Technological Progress ◽  
High Speed ◽  
Operating Cost ◽  
Cost Savings ◽  
Variable Rate ◽  
Net Returns ◽  
Variable Rate Application ◽  
Technology Changes ◽  
Profit Potential

Recent technological progress in high-speed planting (HSP) warrants economic analysis of its potential. A whole farm optimization model of a 1000 ha Kentucky, USA corn and soybean operation finds that operating cost savings (labor, fuel, tractor repairs) and yield increases couple in recovering annual ownership costs of HSP technology. Changes in farm net returns are positive for all 12-row planter scenarios and all double speed cases for the 16-row planter but not for a 50% increase in speed with the 16-row planter. The greatest profit potential occurred when adopting the combination of HSP and variable rate application (VRA), with increased net returns of up to 6.57% compared to conventional speed no VRA for the 12-row planter.

A quality-driven stability analysis framework based on state fluctuation space model for manufacturing process

2018 ◽  
Vol 233 (3) ◽  
pp. 436-447
Author(s):  
Liping Zhao ◽  
Sheng Hu ◽  
Yiyong Yao
Keyword(s):  
Stability Analysis ◽  
Manufacturing Process ◽  
Single Mode ◽  
Good Effect ◽  
Support Vector ◽  
Support Vector Data Description ◽  
Analysis Framework ◽  
Process Stability ◽  
Space Model ◽  
Operating Modes

Industrial manufacturing processes often show multiple operating modes, where different modes present different regularities, so real-time monitor and analyzing the quality state stability is an important way to ensure product quality. This paper proposes a state-driven fluctuation space model for quality stability analysis for multimode manufacturing process. First, the whole process is divided into many sub-processes and the multimode formation mechanism is analyzed to form the stability analysis framework. Then each single-mode quality state fluctuation space model is built based on multi-kernel support vector data description method to determine the max effective fluctuation border of the process state. For the current process state, the deep neural network (DNN) is adopted to extract process state features automatically and recognize the mode type. Thus appropriate quality stable fluctuation space model is selected to monitor and analyze the process stability state. Finally, a case study is performed to evaluate the feasibility of proposed stability analysis method, and the result reveals that the method shows good effect for analyzing the process stability in manufacturing process.

scholarly journals Optimum Energy Flow Management of a Grid-Tied Photovoltaic-Wind-Battery System considering Cost, Reliability, and CO2 Emission

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Meryeme Azaroual ◽  
Mohammed Ouassaid ◽  
Mohamed Maaroufi
Keyword(s):  
Greenhouse Gas Emission ◽  
Storage System ◽  
Operating Cost ◽  
Cost Savings ◽  
Substantial Effect ◽  
Energy Management Strategy ◽  
Optimum Energy ◽  
Ghg Reduction ◽  
Reliable Model ◽  
Cover Ratio

The main goal of this paper is to explore the performance of a residential grid-tied hybrid (GTH) system which relies on economic and environmental aspects. A photovoltaic- (PV-) wind turbine- (WT-) battery storage system with maximizing self-consumption and time-of-use (ToU) pricing is conducted to examine the system efficiency. In so doing, technical optimization criteria with taking into consideration renewable energy benefits including feed-in-tariff (FIT) and greenhouse gas emission (GHG) reduction are analyzed. As the battery has a substantial effect on the operational cost of the system, the energy management strategy (EMS) will incorporate the daily operating cost of the battery and the effect of the degradation. The model can give the opportunity to the network to sell or purchase energy from the system. The simulation results demonstrate the effectiveness of the proposed approach in which the new objective function achieves the maximum cost-saving (99.81%) and income (5.16 $/day) compared to other existing strategies as well as the lowest GHG emission. Furthermore, the battery enhances the best daily self-consumption and load cover ratio. Then, as the model is nonlinear, a comparison with other existing algorithms is performed to select the feasible, robust, and reliable model for the residential application. A hybrid algorithm (HGAFMINCON) is developed to demonstrate the superiority of the algorithm over FMINCON and GA shown in terms of cost savings and income.

scholarly journals Application of physical theory of cavity in the construction of double skin facades

2021 ◽  
Vol 9 (1) ◽  
pp. 40-53
Author(s):  
Boris Bielek ◽  
Daniel Szabó ◽  
Josip Klem ◽  
Kristína Kaniková
Keyword(s):  
Flow Line ◽  
Aerodynamic Resistance ◽  
Climatic Conditions ◽  
Operating Modes ◽  
Outdoor Climate ◽  
Energy Needs ◽  
In Situ Experiments ◽  
Correct Function ◽  
Double Skin ◽  
Double Skin Facades

Abstract The article deals with the issue of double skin transparent facades as a new technological-operational system of transparent exterior walls. Especially of high-rise buildings, which with its operating modes ingeniously uses a renewable source of solar energy to reduce the energy needs of the building. The basic precondition for the correct function of the double skin facade is its functional aerodynamics in any climatic conditions of the outdoor climate. In the critical state of windlessness, the aerodynamic quantification of a double skin facade is the total aerodynamic resistance of the cavity, which consists of the aerodynamic frictional resistances along the length of the air flow line and local aerodynamic resistances of the cavity. The article analyses the functional aerodynamics on two frequented types of double skin facades with a narrow type and corridor type cavity. At the end it confronts functional aerodynamics with the results of their temperature, aerodynamic and energy regime obtained from in-situ experiments.

scholarly journals Estimating Cost Savings of Coordinating Regional Non-Emergency Human Transport Services

2010 ◽  
Author(s):  
Ryoichi Sakano ◽  
Julian Benjamin
Keyword(s):  
Public Transportation ◽  
Local Community ◽  
Operating Cost ◽  
Cost Savings ◽  
Transportation Systems ◽  
Transportation Services ◽  
Transport Services ◽  
Transportation Agencies ◽  
Human Transport ◽  
Current Operating

Local public transportation agencies provide a nonemergency human transport service to nearby hospitals and doctors' offices. Some users require specialized medical services at a hospital located out of the normal service area. In the Piedmont/Triad region of North Carolina, the Piedmont Authority for Regional Transportation (PART) began PART Connections in April 2004, to provide two daily transportation services between the Piedmont/Triad area and the UNC/Duke medical areas. Using current operating cost data of participating transportation systems, round-trip costs to the UNC/Duke medical areas from each county and to the nearest PART Connections stop are estimated. Given the actual number of passengers served by PART Connections during the first nine-month period of the service, the net saving in the operating cost by participating PART Connections is estimated for each system. Then, the total service hours saved by using PART Connections are estimated for each system, and are used to estimate the number of additional passengers served within the system. It is estimated that PART Connections could provide a net saving of $38,000 on operation expenses annually to the participating four county transportation systems. More importantly, PART Connections would enable the four county systems to provide more than 10,000 additional passenger trips within each county annually, by using the saved resources. In addition, 12 local community transportation providers in 15 western counties of the Piedmont/Triad region, which currently do not participate in PART Connections, are estimated to save a modest $9,600 in total annually, by using PART Connections.

scholarly journals Heat pump systems: A mini review

2021 ◽  
Vol 4 (2) ◽  
pp. 73-81
Author(s):  
Mohammad Omar Temori ◽  
František Vranay
Keyword(s):  
Heat Pump ◽  
Electricity Consumption ◽  
Cost Savings ◽  
Electrical Energy ◽  
Primary Energy ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Heating And Cooling ◽  
Ground Source ◽  
Reduce Electricity Consumption

In this work, a mini review of heat pumps is presented. The work is intended to introduce a technology that can be used to income energy from the natural environment and thus reduce electricity consumption for heating and cooling. A heat pump is a mechanical device that transfers heat from one environmental compartment to another, typically against a temperature gradient (i.e. from cool to hot). In order to do this, an energy input is required: this may be mechanical, electrical or thermal energy. In most modern heat pumps, electrical energy powers a compressor, which drives a compression - expansion cycle of refrigerant fluid between two heat exchanges: a cold evaporator and a warm condenser. The efficiency or coefficient of performance (COP), of a heat pump is defined as the thermal output divided by the primary energy (electricity) input. The COP decreases as the temperature difference between the cool heat source and the warm heat sink increases. An efficient ground source heat pump (GSHP) may achieve a COP of around 4. Heat pumps are ideal for exploiting low-temperature environmental heat sources: the air, surface waters or the ground. They can deliver significant environmental (CO2) and cost savings.

Economic assessment of sludge handling and environmental impact of sludge treatment in a reed bed system

2015 ◽  
Vol 71 (9) ◽  
pp. 1286-1292 ◽  
Author(s):  
Steen Nielsen
Keyword(s):  
Environmental Impact ◽  
Agricultural Land ◽  
Operating Cost ◽  
Cost Savings ◽  
Economic Assessment ◽  
Land Application ◽  
Sludge Dewatering ◽  
Sludge Treatment ◽  
Significant Saving ◽  
Reed Bed

The effect on the environment of the establishment and operation of a sludge treatment reed bed system (STRB) is quite limited compared to mechanical sludge dewatering, with its accompanying use of energy and chemicals. The assessment presented here of the investment, operation and maintenance costs of a typical STRB, and of the related environmental impact, is based on the experiences gained from the operation of a large number of STRB in Denmark. There are differences in the environmental perspectives and costs involved in mechanical sludge dewatering and disposal on agricultural land compared to STRB. The two treatment methods were considered for comparison based on a treatment capacity of 550 tons of dry solids per year and with land application of the biosolids in Denmark. The initial capital cost for STRB is higher than a conventional mechanical system; however, an STRB would provide significant power and operating-cost savings, with a significant saving in the overall cost of the plant over 20–30 years. The assessment focuses on the use of chemicals, energy and greenhouse gas emissions and includes emptying, sludge residue quality and recycling. STRB with direct land application is the most cost-effective scenario and has the lowest environmental impact. A sludge strategy consisting of an STRB will be approximately DKK 536,894–647,636 cheaper per year than the option consisting of a new screw press or decanter.

Unstable Vibrations of a Wind Turbine Tower With Two Blades

2012 ◽  
Author(s):  
Takashi Ikeda ◽  
Yuji Harata ◽  
Yukio Ishida
Keyword(s):  
Wind Turbine ◽  
Equations Of Motion ◽  
Single Mode ◽  
Single Frequency ◽  
Dual Mode ◽  
Response Curves ◽  
Moments Of Inertia ◽  
System Parameters ◽  
Wind Turbine Tower ◽  
The Asymmetry

Unstable vibrations of a two-blade wind turbine tower are theoretically investigated. The theoretical model is a five-degree-of-freedom (5DOF) system, however, the equations of motion are derived separately for 3DOF subsystem (I) and 2DOF subsystem (II). Parametric excitation due to the asymmetry of the moments of inertia of the blade rotor is included only in subsystem (I). Frequency equations are derived and natural frequency diagrams are calculated to clearly demonstrate both the rotational speeds where unstable regions appear and which type of unstable vibrations may occur. It is found that at most, five unstable regions may appear depending on the values of the system parameters in subsystem (I). Two types of unstable vibrations may occur; single mode including a single frequency and dual mode including two frequencies. The influences of the asymmetry of moments of inertia, tower rigidity, and installation position of the blade rotor on the response of the system are also theoretically investigated. Van der Pol’s method is applied to determine the expressions for the response curves. The influences of the blade rotor unbalances on the translational, inclinational and torsional vibrations of the tower are shown. It is found that the amplitudes of the response curves corresponding to single and dual mode are infinite and finite at their boundaries, respectively. The validity of the theoretical analysis is confirmed by numerical simulations.

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