scholarly journals Design and construction of a cold production simulator system: chiller

2019 ◽  
Vol 3 (3) ◽  
pp. 31-40
Author(s):  
Ricardo Fabricio Muñoz Farfán ◽  
Telly Yarita Macías Zambrano ◽  
Vicente Paúl Zambrano Valencia ◽  
Victor Manuel Delgado Sosa
Keyword(s):  
Cooling Tower ◽  
Maximum Flow ◽  
Cooling Capacity ◽  
Design Parameters ◽  
Direct Expansion ◽  
Pumping System ◽  
Expansion System ◽  
Ice Water ◽  
Proper Operation ◽  
Design And Construction

The design and construction of a cold production system from the ice water submitted by a mechanical direct expansion system contributing to the development of knowledge in the area of air conditioning were carried out. Among the technical design parameters, a direct expansion system with cooling capacity of 9000 BTU/Hrs, R134 refrigerant gas to a turbine for the work of the Fan Coil of ½ Hp of force 220 V was selected, as was the fan motor of the cooling tower as fundamental means for heat transfer. The recirculation pumping system is carried out by pumps of 0.37 kW of power and a maximum flow of 40 l/min. For both the evaporator sump (cold) and the condenser sump (hot). The work stage is given in two independent circuits, the Fan Coil system is connected to the evaporator sump and the cooling tower, in turn, is connected to the condensation system for proper operation and achieve condensation temperatures of 35 ° C and in case of having water requirements in the cold sump, the tower is connected by means of an electromagnetic valve for its supply.

scholarly journals Investigation on the Optimum Design of Heat Exchangers in a Hybrid Closed Circuit Cooling Tower

1970 ◽  
Vol 37 ◽  
pp. 52-57
Author(s):  
MMA Sarker
Keyword(s):  
Heat Exchanger ◽  
Optimum Design ◽  
Heat Exchangers ◽  
Cooling Tower ◽  
Cooling Capacity ◽  
Closed Circuit ◽  
Design Parameters ◽  
Air Inlet ◽  
Staggered Arrangement ◽  
Temperature And Pressure

Investigation on the optimum design of a heat exchanger in a Hybrid Closed Circuit Cooling Tower having a rated capacity of 1RT is performed experimentally. The heat exchanger of dimension 0.4mx0.33mx0.572m has 15x7 bare type 15.88mm OD copper coils in staggered arrangement. The relevant design parameters were selected based on the typical East Asian meteorological constrains for the year-round smooth operation of the cooling tower. This study presents results related to the cooling capacity and the cooling efficiency with respect to wet bulb temperature and pressure drop with respect to air inlet velocity. Results are also presented in terms of number of transfer units (NTU). Cooling capacity was found to be close to the rated one for the wet mode but low in dry mode operation. Keywords: Hybrid closed circuit cooling tower, Cooling capacity, Wet mode, Dry modedoi:10.3329/jme.v37i0.820Journal of Mechanical Engineering Vol.37 June 2007, pp.52-77

scholarly journals Application and Design Aspects of Ground Heat Exchangers

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2134
Author(s):  
Luka Boban ◽  
Dino Miše ◽  
Stjepan Herceg ◽  
Vladimir Soldo
Keyword(s):  
Renewable Energy ◽  
Heat Exchangers ◽  
Geothermal Energy ◽  
Energy Demand ◽  
Design Parameters ◽  
Direct Expansion ◽  
Alternative Source ◽  
Ground Heat Exchangers ◽  
Point Of Interest ◽  
Constant Source

With the constant increase in energy demand, using renewable energy has become a priority. Geothermal energy is a widely available, constant source of renewable energy that has shown great potential as an alternative source of energy in achieving global energy sustainability and environment protection. When exploiting geothermal energy, whether is for heating or cooling buildings or generating electricity, a ground heat exchanger (GHE) is the most important component, whose performance can be easily improved by following the latest design aspects. This article focuses on the application of different types of GHEs with attention directed to deep vertical borehole heat exchangers and direct expansion systems, which were not dealt with in detail in recent reviews. The article gives a review of the most recent advances in design aspects of GHE, namely pipe arrangement, materials, and working fluids. The influence of the main design parameters on the performance of horizontal, vertical, and shallow GHEs is discussed together with commonly used performance indicators for the evaluation of GHE. A survey of the available literature shows that thermal performance is mostly a point of interest, while hydraulic and/or economic performance is often not addressed, potentially resulting in non-optimal GHE design.

scholarly journals Design and Construction Optical Pumping System

2013 ◽  
Vol 10 (2) ◽  
pp. 462-471
Author(s):  
Baghdad Science Journal
Keyword(s):  
Current Density ◽  
Optical Pumping ◽  
Electrical Energy ◽  
Discharge Voltage ◽  
Flash Lamp ◽  
Damping Factor ◽  
Discharge Current Density ◽  
Pumping System ◽  
Impedance Parameters ◽  
Design And Construction

In this work the design and construction of optical pumping system was presented. The parameters of the pumping source to obtain discharge current density sufficient to shift the flash lamp spectrum towards uv portion of spectrum were measured.The current density was supplied to the flash lamp must be greater than 4000Amp./cm2 to obtain the spectral range wavelength lies between 0.2 and 0.35?m. The current density was obtained by a capacitor 50?F, at 7KV discharge voltage. The applied electrical energy to the flash lamp was more than 1200 J, and the current density was around 5000 Amp./cm2.The electrical parameters of the flash lamp were calculated. The impedance parameters(K0) from the voltage and the peak current pulse was measured in range equal to 57, while the damping factor(?) was 1.3. The energy of the flash lamp was around 75% from the input electrical energy. The external trigger circuit was limited the increase the applied voltage, which is responsible for the damping factor.

scholarly journals Predicting the Mechanical Properties of Bimrocks with High Rock Block Proportions Based on Resonance Testing Technology and Damage Theory

2019 ◽  
Vol 9 (17) ◽  
pp. 3537
Author(s):  
Yuexiang Lin ◽  
Limin Peng ◽  
Mingfeng Lei ◽  
Xiang Wang ◽  
Chengyong Cao
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Constitutive Model ◽  
Uniaxial Compression ◽  
Rock Block ◽  
Dynamic Elastic Modulus ◽  
Parameter Determination ◽  
Design Parameters ◽  
Damage Theory ◽  
Design And Construction

Block-in-matrix-rocks (bimrocks) are very complicated geological masses that cause many challenging problems during the design and construction of engineering projects, such as parameter determination and landsliding. Successful engineering design and construction depends on a suitable constitutive model and reliable design parameters for geological masses. In this paper, the vibration attenuation signal of welded bimrocks was obtained and studied using resonance test technology. Combined with a uniaxial compression test, a constitutive model was proposed to describe the mechanical behavior of welded bimrocks. On this basis, the relations between the dynamic elastic modulus and the physical parameters of bimrocks were established, which included macroscopic mechanical parameters and damage constitutive parameters. Consequently, a new technological process was proposed to provide quick identification of the mechanical properties of welded bimrocks. The results indicate that the dynamic elastic modulus is highly correlated with the rock block proportion (RBP) and uniaxial compression strength (UCS). It is an effective parameter to predict the strength of the bimrocks with high RBPs. Additionally, the proposed constitutive model, which is based on damage theory, can accurately simulate the strain softening behavior of the bimrocks. Combining the resonant frequency technology and the proposed constitutive model, the complete stress strain curve can be obtained in a rapid and accurate manner, which provides a further guarantee of the stability and safety of underground engineering.

scholarly journals Operating Range for a Combined, Building-Scale Liquid Air Energy Storage and Expansion System: Energy and Exergy Analysis

Entropy ◽  
2018 ◽  
Vol 20 (10) ◽  
pp. 770 ◽  
Author(s):  
Todd Howe ◽  
Anthony Pollman ◽  
Anthony Gannon
Keyword(s):  
Energy Storage ◽  
Ambient Temperature ◽  
Energy Production ◽  
Exergy Analysis ◽  
Expansion Method ◽  
Direct Expansion ◽  
Expansion Turbine ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Expansion System

This paper presents the results of an ideal theoretical energy and exergy analysis for a combined, building scale Liquid Air Energy Storage (LAES) and expansion turbine system. This work identifies the upper bounds of energy and exergy efficiency for the combined LAES-expansion system which has not been investigated. The system uses the simple Linde-Hampson and pre-cooled Linde-Hampson cycles for the liquefaction subsystem and direct expansion method, with and without heating above ambient temperature, for the energy production subsystem. In addition, the paper highlights the effectiveness of precooling air for liquefaction and heating air beyond ambient temperature for energy production. Finally, analysis of the system components is presented with an aim toward identifying components that have the greatest impact on energy and exergy efficiencies in an ideal environment. This work highlights the engineering trade-space and serves as a prescription for determining the merit or measures of effectiveness for an engineered LAES system in terms of energy and exergy. The analytical approach presented in this paper may be applied to other LAES configurations in order to identify optimal operating points in terms of energy and exergy efficiencies.

scholarly journals Evaluation and Verification Method of Cooling Capacity of Counterflow Natural Ventilation Cooling Tower

2019 ◽  
Vol 295 ◽  
pp. 012051
Author(s):  
Wen Cai ◽  
Jin Lu ◽  
Lin Guo Chen ◽  
Wen Chen ◽  
Zhong-hai Wan ◽  
...  
Keyword(s):  
Natural Ventilation ◽  
Cooling Tower ◽  
Cooling Capacity ◽  
Verification Method

Analysis of Drain Pumping System for Nuclear Power Plants Under Transient Turbine Loads

1975 ◽  
Vol 97 (4) ◽  
pp. 619-627
Author(s):  
G. S. Liao
Keyword(s):  
System Design ◽  
Power Plants ◽  
Analytical Approach ◽  
Careful Consideration ◽  
Operating Conditions ◽  
Cycle Performance ◽  
Design Parameters ◽  
Pressure Decay ◽  
Pumping System ◽  
Tank System

Many nuclear stations do not incorporate deaerators in their feedwater heating systems. To attain high turbine cycle performance without a deaerator, a drain pumping system is widely used for returning hot drains from the high-pressure heaters to the feedwater system. With a greatly increased feedwater flow for nuclear units, together with the drain pumping system being moved to a higher extraction point, the heater–drain tank system will be subject to a rapid pressure decay under turbine load rejections. In addition, the drain pump suction flow reduces considerably, thereby increasing the suction pipe resident time. It is these critical changes in operating conditions that should receive careful consideration in drain pumping system design. This paper presents an analytical approach for determining drain tank pressure decay, drain pump suction pressure decay, and transient behavior of the heater–drain tank system based on analysis of closed feedwater heater performance and the varying feedwater temperature entering the heater under turbine load rejections. The emphasis is placed on adequate and optimum design of a drain pumping system, including a discussion of some design criteria to be followed, as well as sizing of the pressure equalizer between heater and drain tank. All mathematical equations required for determining the design parameters are derived. Finally, some example calculations are given to illustrate the application of the developed analytical approach to system design.

scholarly journals CALCULATION MODEL OF THE SYSTEM OF THERMAL STABILIZATION OF THE ELEMENTS OF RADIO ELECTRONIC EQUIPMENT

2019 ◽  
Vol 46 (1) ◽  
pp. 42-52
Author(s):  
T. A. Ismailov ◽  
A. M. Ibragimova
Keyword(s):  
Heat Exchanger ◽  
Melting Point ◽  
Computational Model ◽  
Flow Rate ◽  
Fluid Motion ◽  
Thermal Stabilization ◽  
Maximum Flow ◽  
Cooling Capacity ◽  
Electronic Equipment ◽  
Stable Operation

Objectives. The aim of the study is to develop a computational model of the system of thermal stabilization of elements of electronic equipment (REA), based on the joint use of working substances with a stable melting point and the liquid method of heat sink, the study of the thermophysical processes occurring during its operation.Method. A computational model of the REA thermostabilization system based on the use of working substances with a stable melting point has been created. The model includes a description of the heat exchange processes during laminar fluid motion in a heat exchanger, determining the duration of stable operation of the REA elements, depending on the flow rate and cooling capacity of a thermoelectric battery (TEB).Result. The graphs of dependences reflecting the main characteristics of the developed system were obtained, in particular, the dependence of the change in the duration of maintaining the stable temperature of the REA element on its power, the temperature of the cold junctions of the thermopile, scattering at different maximum flow rates of the heat exchanger.Conclusions. The results of the calculations determine that the duration of complete penetration of the working substance, corresponding to the duration of stable operation of CEA elements, can be within the required limits only if certain very specific conditions are met: using a sufficient amount of the working substance in the heat stabilizing system, corresponding to the temperature and flow rate of the liquid in the heat exchanger. These parameters of the thermal stabilization system must be selected based on the amount of heat emitted per unit of time by the REA element, the duration of its operation, and the characteristics of the thermopile used to cool the fluid.

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