scholarly journals Improving the cooling system of ship equipment

2020 ◽  
Author(s):  
А.В. Фомин ◽  
Е.В. Фомин
Keyword(s):  
Power Plants ◽  
High Efficiency ◽  
Cooling System ◽  
Heat Removal ◽  
Normal Operation ◽  
Water Cooling ◽  
Cooling Systems ◽  
Start Up ◽  
Membrane Type ◽  
Water Cooling System

В статье представлены результаты исследования эффективности работы системы охлаждения корабельного оборудования и предложены конструктивные решения, позволяющие модернизировать данную систему. В настоящее время, для обеспечения нормальной работы корабельного оборудования, применяются системы охлаждения. В корабельных энергетических установках распространены системы водяного охлаждения из-за целого ряда преимуществ. К ним относится и высокая эффективность теплоотвода, и меньшее влияние внешней среды, а также более надежный пуск и возможность использования энергии отводимого тепла для других нужд. Одним из основных элементов в таких системах является расширительный бак гравитационного типа, обеспечивающий правильную циркуляцию дистиллированной воды во внутреннем контуре и расположенный в верхней точке системы. Однако практика испытаний и эксплуатации показала, что есть и серьезный недостаток в таком расположении бака – в случаи его перелива или разрыва может пострадать дорогостоящее оборудование, расположенное ниже. В связи с этим, определены направления по совершенствованию системы водяного охлаждения корабельного оборудования, которые связаны с применением расширительного бака мембранного типа и использования воздухоудаляющих клапанов. The article presents the results of a study of the efficiency of the cooling system of ship equipment and offers design solutions that allow to modernize this system. Currently, to ensure the normal operation of ship's equipment, cooling systems are used. Water cooling systems are common in ship power plants due to a number of advantages. These include high efficiency of heat removal, less influence of the external environment, as well as more reliable start-up and the ability to use the energy of the heat being withdrawn for other needs. One of the main elements in such systems is a gravity-type expansion tank that ensures proper circulation of distilled water in the internal circuit and is located at the top of the system. However, the practice of testing and operation has shown that there is a serious drawback in this arrangement of the tank – in cases of overflow or rupture, expensive equipment located below may suffer. In this regard, the directions for improving the water cooling system of ship equipment, which are associated with the use of an expansion tank of the membrane type and the use of air-removing valves, have been identified.

Cooling Thin Parts of Pressure Casting Moulds by Means of Liquid CO2

2015 ◽  
Vol 669 ◽  
pp. 71-78
Author(s):  
Iva Nováková ◽  
Martin Seidl ◽  
Pavel Brdlík ◽  
Jan Štverák ◽  
Jaromír Moravec
Keyword(s):  
Cooling System ◽  
Heat Removal ◽  
Pressure Casting ◽  
Optimal Temperature ◽  
Heat Transfer Medium ◽  
Cooling Systems ◽  
Start Up ◽  
Casting Cycle ◽  
Heat Processes ◽  
Heat Amount

To ensure optimal temperature conditions during casting cycle the pressure casting moulds are equipped with cooling systems. These days the cooling systems used in the most of Czech foundry plants enable pre-heating of pressure casting moulds to the working temperature before start-up of production and during casting operation to keep optimal temperature balance among the casting and the mould. Pressure casting mould temperature balance is provided by system of mutually connected channels which are mostly parallel with parting line and inside those the heat transfer medium flows. However such a system allows removal only limited heat amount from the most overheated places of the casting mould and does not allow heat removal from cores of small diameters. This inhomogeneous heat removal causes porosity of the casting in certain areas and also lifetime of the pressure casting mould is dramatically reduced. Cooling by means of liquid CO2 was developed as one of the new cooling possibilities for such places in the pressure casting mould where the heat is concentrated and for standard cooling systems it is too complicated to fully control the heat processes there. The paper deals with the behaviour monitoring of the new cooling system utilizing the potential of liquid CO2. This system was applied into pressure casting mould core and its final impact on the casting quality in the close surrounding was observed.

Design, Fabrication and Testing of Cooling Systems for a Particle Accelerator

2017 ◽  
Author(s):  
John D. Bernardin ◽  
Walter C. Barkley ◽  
Jack Gioia ◽  
Pilar Marroquin
Keyword(s):  
Cooling System ◽  
Electrical Energy ◽  
Temperature Data ◽  
Particle Accelerator ◽  
Water Cooling ◽  
Large Structure ◽  
Science Center ◽  
Cooling Systems ◽  
Water Cooling System ◽  
Selection Of

This paper discusses the design, analysis, and testing of a Water Cooling System (WCS) for a Drift Tube Linear (DTL) Particle Accelerator structure at the Los Alamos Neutron Science Center (LANSCE). The DTL WCS removes large amounts of dissipated electrical energy in a very controlled manner to maintain a constant temperature of the large structure. First, the design concept and method of water temperature control is discussed. Second, the layout of the water cooling system, including the selection of plumbing components and instrumentation is presented. Next, the development of a numerical nodal network model, used to size the plumbing, pump, control valves, and mixing tank (heat exchanger), is discussed. Finally, empirical pressure, flow rate, and temperature data from a functioning DTL water cooling system are used to assess the water cooling system performance and validate the numerical model.

scholarly journals Digital Twins of the Water Cooling System in a Power Plant Based on Fuzzy Logic

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6737
Author(s):  
Carlos Antonio Alves de Araujo Junior ◽  
Juan Moises Mauricio Villanueva ◽  
Rodrigo José Silva de Almeida ◽  
Isaac Emmanuel Azevedo de Medeiros
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Cooling System ◽  
Ambient Air ◽  
Fuzzy Rules ◽  
Percentage Error ◽  
Water Cooling ◽  
Twin Model ◽  
Digital Twins ◽  
Water Cooling System

In the search for increased productivity and efficiency in the industrial sector, a new industrial revolution, called Industry 4.0, was promoted. In the electric sector, power plants seek to adapt these new concepts to optimize electric power generation processes, as well as to reduce operating costs and unscheduled downtime intervals. In these plants, PID control strategies are commonly used in water cooling systems, which use fans to perform the thermal exchange between water and the ambient air. However, as the nonlinearities of these systems affect the performance of the drivers, sometimes a greater number of fans than necessary are activated to ensure water temperature control which, consequently, increases energy expenditure. In this work, our objective is to develop digital twins for a water cooling system with auxiliary equipment, in terms of the decision making of the operator, to determine the correct number of fans. This model was developed based on the algorithm of automatic extraction of fuzzy rules, derived from the SCADA of a power plant located in the capital of Paraíba, Brazil. The digital twins can update the fuzzy rules in the case of new events, such as steady-state operation, starting and stopping ramps, and instability. The results from experimental tests using data from 11 h of plant operations demonstrate the robustness of the proposed digital twin model. Furthermore, in all scenarios, the average percentage error was less than 5% and the average absolute temperature error was below 3 °C.

Three Dimensional CFD Simulation of Condensation Inside Inclined Tubes

2017 ◽  
Author(s):  
Amirhosein Moonesi Shabestary ◽  
Eckhard Krepper ◽  
Dirk Lucas ◽  
Thomas Höhne
Keyword(s):  
Heat Transfer ◽  
Annular Flow ◽  
Cfd Simulation ◽  
Cooling System ◽  
Heat Removal ◽  
Normal Operation ◽  
Cooling Systems ◽  
Horizontal Pipes ◽  
Subcooled Water ◽  
Operation Conditions

The current paper comprises CFD-modelling and simulation of condensation and heat transfer inside horizontal pipes. Designs of future nuclear boiling water reactor concepts are equipped with emergency cooling systems which are passive systems for heat removal. The emergency cooling system consists of slightly inclined horizontal pipes which are immersed in a tank of subcooled water. At normal operation conditions, the pipes are filled with water and no heat transfer to the secondary side of the condenser occurs. In the case of an accident the water level in the core is decreasing, steam comes in the emergency pipes and due to the subcooled water around the pipe, this steam will condense. The emergency condenser acts as a strong heat sink which is responsible for a quick depressurization of the reactor core when any accident happens. The actual project is defined in order to model all these processes which happen in the emergency cooling systems. The most focus of the project is on detection of different morphologies such as annular flow, stratified flow, slug flow and plug flow. The first step is the investigation of condensation inside a horizontal tube by considering the direct contact condensation (DCC). Therefore, at the inlet of the pipe an annular flow is assumed. In this step, the Algebraic Interfacial Area Density (AIAD) model is used in order to simulate the interface. The second step is the extension of the model to consider wall condensation effect as well which is closer to the reality. In this step, the inlet is pure steam and due to the wall condensation, a liquid film occurs near the wall which leads to annular flow. The last step will be modelling of different morphologies which are occurring inside the tube during the condensation via using the Generalized Two-Phase Flow (GENTOP) model extended by heat and mass transfer. By using GENTOP the dispersed phase is able to be considered and simulated. Finally, the results of the simulations will be validated by experimental data which will be available in HZDR. In this paper the results of the first part has been presented.

An Estimation of the Performance Limits of Dry Cooling on Trough-Type Solar Thermal Plants

2008 ◽  
Author(s):  
Huifang Deng ◽  
Robert F. Boehm
Keyword(s):  
Power Plants ◽  
High Efficiency ◽  
Cooling System ◽  
Low Cost ◽  
Performance Limits ◽  
Cooling Systems ◽  
Solar Power Plants ◽  
Solar Resource ◽  
Dry Cooling ◽  
The Ideal

The southwestern US is an ideal location for solar power plants due to its abundant solar resource, while there is a difficulty in implementing wet cooling systems due to the shortage of water in this region. Dry cooling could be an excellent solution for this, if it could achieve a high efficiency and low cost as wet cooling. Some dry cooling systems are currently in operation, and investigations of their performance have been reported in the literature. This paper looks into the limits to the power production implicit in dry cooling, assuming that improvements might be made to the system components. Use of higher performance heat transfer surfaces is one such possible improvement. We have developed a model of a fairly typical, but simplified, solar trough plant, and simulated thermodynamic performance of this with the software Gatecycle. We have examined the power generation and cycle efficiency of the plant for the Las Vegas vicinity with conventional wet cooling and conventional dry cooling cases considered separately using this software. TMY2 data are used for this location for this purpose. Similarly, the same studies are carried out for “ideal” cooling systems as a comparison. We assumed that in the ideal dry cooling system, the condensing temperature is the ambient dry bulb temperature, and in the ideal wet cooling system, it is the ambient wet bulb temperature. It turned out that the ideal dry cooling system would significantly outperform the conventional wet cooling system, indicating the possibility of the dry cooling system being able to achieve increased performance levels with component improvements.

Technoeconomic Optimization of Turbocompression Cooling Systems

2017 ◽  
Author(s):  
Spencer C. Gibson ◽  
Derek Young ◽  
Todd M. Bandhauer
Keyword(s):  
Heat Exchangers ◽  
Power Plants ◽  
High Efficiency ◽  
Waste Heat ◽  
Cooling System ◽  
Payback Period ◽  
Low Grade ◽  
Air Cooling ◽  
Total System ◽  
Cooling Systems

Low grade waste heat streams with temperatures near 100°C are abundant, presenting a significant opportunity to reduce primary energy consumption across the world. For example, thermally activated cooling systems can utilize waste heat to meet air conditioning loads. Recently, a turbocompression cooling system (TCCS) that utilizes low grade waste heat from power plants was investigated to improve the economic viability of dry air cooling systems. The TCCS utilizes Rankine and vapor-compression cycles that are directly coupled through a high efficiency centrifugal turbine and a compressor. In this paper, a coupled thermodynamic, heat transfer, and economic model for a TCCS is applied to utilizing low grade engine coolant waste heat to meet cargo ship cooling load requirements while minimizing the payback period for a particular operational scenario. The results of this study show that with a constant heat input of 2 MW, the liquid coupled turbocompression cooling system provided 642 kW of cooling with a payback period of 2 years and 6 months, and the total cost of the heat exchangers made up more than 84% of the total system cost. In addition, a sensitivity analysis showed that the effectiveness of the power cycle heat exchangers have a stronger influence on the payback period than the cooling cycle heat exchangers.

scholarly journals Studying the Reduction of Water Use in Integrated Solar Combined-Cycle Plants

2019 ◽  
Vol 11 (7) ◽  
pp. 2085 ◽  
Author(s):  
Fontina Petrakopoulou ◽  
Marina Olmeda-Delgado
Keyword(s):  
Water Consumption ◽  
Power Plants ◽  
High Efficiency ◽  
Cooling System ◽  
Combined Cycle ◽  
Special Focus ◽  
Cooling Systems ◽  
Cooling Fluid ◽  
Hybrid Cooling ◽  
Dry Cooling

With vast amounts of water consumed for electricity generation and water scarcity predicted to rise in the near future, the necessity to evaluate water consumption in power plants arises. Cooling systems are the main source of water consumption in thermoelectric power plants, since water is a cooling fluid with relatively low cost and high efficiency. This study evaluates the performance of two types of power plants: a natural gas combined-cycle and an integrated solar combined-cycle. Special focus is made on the cooling system used in the plants and its characteristics, such as water consumption, related costs, and fuel requirements. Wet, dry, and hybrid cooling systems are studied for each of the power plants. While water is used as the cooling fluid to condense the steam in wet cooling, dry cooling uses air circulated by a fan. Hybrid cooling presents an alternative that combines both methods. We find that hybrid cooling has the highest investment costs as it bears the sum of the costs of both wet and dry cooling systems. However, this system produces considerable fuel savings when compared to dry cooling, and a 50% reduction in water consumption when compared to wet cooling. As expected, the wet cooling system has the highest exergetic efficiency, of 1 and 5 percentage points above that of dry cooling in the conventional combined-cycle and integrated solar combined-cycle, respectively, thus representing the lowest investment cost and highest water consumption among the three alternatives. Hybrid and dry cooling systems may be considered viable alternatives under increasing water costs, requiring better enforcement of the measures for sustainable water consumption in the energy sector.

scholarly journals Control of mussel Mytilus galloprovincialis Lamarck fouling in water-cooling systems using plasma discharge

2019 ◽  
Vol 80 (6) ◽  
pp. 1125-1133
Author(s):  
Hui Ge ◽  
Hongcheng Wang ◽  
Zhiying Gao
Keyword(s):  
Mytilus Galloprovincialis ◽  
Cooling System ◽  
Low Frequency ◽  
Input Energy ◽  
Water Cooling ◽  
Cooling Systems ◽  
Liquid Discharge ◽  
Distribution Mode ◽  
Water Cooling System ◽  
Discharge Center

Abstract To prevent marine macrofouling, the anti-fouling effect of liquid discharge on mussels Mytilus galloprovincialis Lamarck was investigated in a simulated water-cooling system. The effects of input energy, mussel distance from discharge center, continuous discharge time, and discharge energy distribution mode on mussel response (death or detachment) were systematically studied. The results showed that excellent anti-fouling effects could be achieved by increasing input energy, but the detachment rate and mortality of mussels decreased sharply when the mussels were farther away from the discharge center. Low frequency discharge for a long, continuous time and multiple stimuli at long intervals improved the anti-fouling effect. Shock waves are the most likely cause of mussel eradication, and the threshold values of peak pressure to prevent mussel settlement and to cause death were 0.02 MPa and 0.05 MPa, respectively.

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