Enhancement of cooling capacity in a hybrid closed circuit cooling tower

2009 ◽  
Vol 29 (16) ◽  
pp. 3328-3333 ◽  
Author(s):  
M.M.A. Sarker ◽  
G.J. Shim ◽  
H.S. Lee ◽  
C.G. Moon ◽  
J.I. Yoon
Keyword(s):  
Cooling Tower ◽  
Cooling Capacity ◽  
Closed Circuit

scholarly journals Numerical Simulation of the Performance Characteristics of the Hybrid Closed Circuit Cooling Tower

2008 ◽  
Vol 13 (1) ◽  
pp. 89-101 ◽  
Author(s):  
M. M. A. Sarker ◽  
E. Kim ◽  
G. C. Moon ◽  
J. I. Yoon
Keyword(s):  
Pressure Drop ◽  
Experimental Measurement ◽  
Cooling Tower ◽  
Cfd Simulation ◽  
Air Flow ◽  
Flow Distribution ◽  
Cooling Capacity ◽  
Performance Characteristics ◽  
Closed Circuit ◽  
Flow Rates

The performance characteristics of the Hybrid Closed Circuit Cooling Tower (HCCCT) have been investigated applying computational fluid dynamics (CFD). Widely reported CFD techniques are applied to simulate the air-water two phase flow inside the HCCCT. The pressure drop and the cooling capacity were investigated from several perspectives. Three different transverse pitches were tested and found that a pitch of 45 mm had lower pressure drop. The CFD simulation indicated that when air is supplied from the side wall of the HCCCT, the pressure drop can be over predicted and the cooling capacity can be under predicted mainly due to the non-uniform air flow distribution across the coil bank. The cooling capacity in wet mode have been calculated with respect to wet-bulb temperature (WBT) and cooling water to air mass flow rates for different spray water volume flow rates and the results were compared to the experimental measurement and found to conform well for the air supply from the bottom end. The differences of the cooling capacity and pressure drop in between the CFD simulation and experimental measurement in hybrid mode were less than 5 % and 7 % respectively for the uniform air flow distribution.

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 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 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

scholarly journals Performance analysis and water quality after ozone application in closed circuit cooling tower systems

2019 ◽  
Author(s):  
Muhmmad Idrus Alhamid ◽  
Setijo Bismo ◽  
Randa Kelvin ◽  
Ardiyansyah Yatim
Keyword(s):  
Water Quality ◽  
Performance Analysis ◽  
Cooling Tower ◽  
Closed Circuit

scholarly journals Simulation of a Solar-Assisted Air-Conditioning System Applied to a Remote School

2019 ◽  
Vol 9 (16) ◽  
pp. 3398 ◽  
Author(s):  
Jesús Armando Aguilar-Jiménez ◽  
Nicolás Velázquez ◽  
Ricardo López-Zavala ◽  
Luis A. González-Uribe ◽  
Ricardo Beltrán ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Thermal Energy ◽  
Cooling Tower ◽  
Cooling System ◽  
Maximum Load ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Solar Thermal Energy ◽  
Heating And Cooling ◽  
Cooling Coils

In this work, we present an absorption cooling system with 35 kW capacity driven by solar thermal energy, installed in the school of Puertecitos, Mexico, an off-grid community with a high level of social marginalization. The cooling system provides thermal comfort to the school’s classrooms through four 8.75-kW cooling coils, while a 110-m2 field of evacuated tube solar collectors delivers the thermal energy needed to activate the cooling machine. The characteristics of the equipment installed in the school were used for simulation and operative analysis of the system under the influence of typical factors of an isolated coastal community, such as the influence of climate, thermal load, and water consumption in the cooling tower, among others. The aim of this simulation study was to determine the best operating conditions prior to system start-up, to establish the requirements for external heating and cooling services, and to quantify the freshwater requirements for the proper functioning of the system. The results show that, with the simulated strategies implemented, with a maximum load operation, the system can maintain thermal comfort in the classrooms for five days of classes. This is feasible as long as weekends are dedicated to raising the water temperature in the thermal storage tank. As the total capacity of the system is distributed in the four cooling coils, it is possible to control the cooling demand in order to extend the operation periods. Utilizing 75% or less of the cooling capacity, the system can operate continuously, taking advantage of stored energy. The cooling tower requires about 750 kg of water per day, which becomes critical given the scarcity of this resource in the community.

Thermal Calculation for Water Cooling Tower To Cool Compressor ATLAS COPCO GA 250 FF

2019 ◽  
Vol 3 (1) ◽  
pp. 193-200
Author(s):  
Yudha Khosala
Keyword(s):  
Oil And Gas ◽  
Cooling Tower ◽  
Air Flow ◽  
Industrial Process ◽  
Cooling Capacity ◽  
Thermal Capacity ◽  
Thermal Calculation ◽  
Water Cooling ◽  
Counter Flow ◽  
Algebraic Formula

The aim of this paper is to choose the correct capacity of Thermal Calculation for Water Cooling Tower to Cool Compressor ATLAS COPCO GA 250 FF since a cooling tower is considered as an essential component for a compressor in an oil and gas pipe manufacture plant. Cooling tower is an equipment device commonly used to dissipate heat from air conditioning, water-cooled refrigeration, power generation units, and industrial process. In this paper, we use a induced draft counter flow tower for the design of cooling tower which based on Merkel’s method. The tower characteristic is determined by Merkel’s method. A simple algebraic formula is used to calculate the optimum water and air flow rate. This paper calculate the cooling tower characteristic, air flow required, efficiency, effectiveness, and cooling capacity of cooling tower need to cool the compressor compare with the availability cooling tower product in the market. In this paper, we will design based on calculation thermal capacity which lead to decentralizing the cooling tower to reach better energy efficiency of the plant.

Performance Evaluation of a 4.5 kW (1.3 Refrigeration Tons) Air-Cooled Lithium Bromide/Water Hot-Water-Fired Absorption Unit

2007 ◽  
Author(s):  
Abdolreza Zaltash ◽  
Andrei Petrov ◽  
Randall Linkous ◽  
Edward Vineyard ◽  
David Goodnack ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Air Conditioning ◽  
Cooling Tower ◽  
Lithium Bromide ◽  
Cooling Capacity ◽  
Hot Water ◽  
Next Generation ◽  
Absorption Chiller ◽  
Flow Rates ◽  
Absorption Chillers

During the summer months, air-conditioning (cooling) is the single largest use of electricity in both residential and commercial buildings with the major impact on peak electric demand. Improved air-conditioning technology has by far the greatest potential impact on the electric industry compared to any other technology that uses electricity. Thermally activated absorption air-conditioning (absorption chillers) can provide overall peak load reduction and electric grid relief for summer peak demand. This paper describes an innovative absorption technology based on integrated rotating heat exchangers to enhance heat and mass transfer resulting in a potential reduction of size, cost, and weight of the “next generation” absorption units. This absorption chiller (RAC) is a 4.5 kW (1.3 refrigeration tons or RT) air-cooled lithium bromide (LiBr)/water unit powered by hot water generated using the solar energy and/or waste heat. Typically LiBr/water absorption chillers are water-cooled units which use a cooling tower to reject heat. Cooling towers require a large amount of space and increase start-up and maintenance costs. However, RAC is an air-cooled absorption chiller which requires no cooling tower. The purpose of this evaluation is to verify RAC performance by comparing the Coefficient of Performance (COP or ratio of cooling capacity to thermal energy input) and the cooling capacity results with those of the manufacturer. The performance of the RAC was tested at Oak Ridge National Laboratory (ORNL) in a controlled environment at various hot and chilled water flow rates, air handler flow rates, and ambient temperatures. Temperature probes, mass flow meters, rotational speed measuring device, pressure transducers, and a web camera mounted inside the unit were used to monitor the RAC via a web control-based data acquisition system using Automated Logic Controller (ALC). Results showed a COP and cooling capacity of approximately 0.58 and 3.7 kW respectively at 35°C (95°F) design condition for ambient temperature with 40°C (104°F) cooling water temperature. This is in close agreement with the manufacturer data of 0.60 for COP and 3.9 kW for cooling capacity. Future work will use these performance results to evaluate the potential benefits of rotating heat exchangers in making the “next-generation” absorption chillers more compact and cost effective without any significant degradation in the performance. Future studies will also evaluate the feasibility of using rotating heat exchangers in other applications.

Modeling Power Generation Water Usage

2015 ◽  
Author(s):  
Jaron J. Peck ◽  
Amanda D. Smith
Keyword(s):  
Power Generation ◽  
Thermoelectric Power ◽  
Power Output ◽  
Power Plants ◽  
Cooling Tower ◽  
Cooling Water ◽  
Rankine Cycle ◽  
Closed Circuit ◽  
Cooling Systems ◽  
Temperature Range

Climate change can have a large effect on thermoelectric power generation. Typical thermoelectric power plants rely on water to cool steam in the condenser in order to produce electricity. Increasing global temperatures can increase average water temperatures as well as decrease the amount of water available for cooling due to evaporation. It is important to know how these parameters can affect power generation and efficiency of power systems, especially when assessing the water needs of a plant for a desired power output and whether a site can fulfill those needs. This paper explains the development of a model that shows how power and efficiency are affected due to changing water temperature and water availability for plants operating on a Rankine cycle. Both a general model of the simple Rankine cycle as well as modifications for regeneration and feedwater heating are presented. Power plants are analyzed for two different types of cooling systems: once-through cooling and closed circuit cooling with a cooling tower. Generally, rising temperatures in cooling water have been found to lower power generation and efficiency. Here, we present a method for quantifying power output and efficiency reductions due to changes in cooling water flow rates or water temperatures. Using specified plant parameters, such as boiler temperature and pressure, power and efficiency are modeled over a 5°C temperature range of inlet cooling water. It was found that over this temperature range, power decrease ranged from 2–3.5% for once through cooling systems, depending on the power system, and 0.7% for plants with closed circuit cooling. This shows that once-through systems are more vulnerable to changing temperatures than cooling tower systems. The model is also applied to Carbon Plant, a coal fired power plant in Utah that withdraws water from the Price River, to show how power and efficiency change as the temperature of the water changes using USGS data obtained for the Price River. The model can be applied to other thermoelectric power stations, whether actual or proposed, to investigate the effects of water conditions on projected power output and plant efficiency.

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