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Shuchen Thakore - One of the best experts on this subject based on the ideXlab platform.
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Model design of condenser for solar assisted geothermal cooling system using software simulation
Modeling Earth Systems and Environment, 2019Co-Authors: Manan Shah, Harshil Kathiriya, Milapkumar Kakadiya, Vinay Boghara, Anirbid Sircar, Shuchen ThakoreAbstract:Condensers are extensively used in refrigeration, air-conditioning and power generation systems. Condenser for the solar assisted geothermal cooling system is designed by using software simulation of condenser’s geometrical and flow parameters. The geothermal cooling system is designed to reduce electricity consumption of compressor during peak hours during the summer period in hot weather condition. The subsurface temperature of the earth around 5–6-m depth is fairly constant throughout the year which fulfills the requirement of cooling inside the building or residence by using water as a heat exchanging medium. Water is circulated in closed loop system buried into subsurface which sinks the heat of refrigerant from condenser inside the subsurface soil. The condenser is designed by comparing results obtained from (1) manual calculation (2) simulation by CHEMCAD software. In order to have a good and optimized design, manual and software-based calculations should be carried out simultaneously and verified with each other. It is found that results obtained from both calculations are approximately same with a minor difference. The geometry and flow parameter of the condenser is determined on the basis of surrounding temperature. The solar panel is used for power generation to reduce electricity consumption by the compressor, pump, and evaporator fan coil. This provides the hybrid solar assisted geothermal cooling system.
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Model design of condenser for solar assisted geothermal cooling system using software simulation
Modeling Earth Systems and Environment, 2019Co-Authors: Manan Shah, Harshil Kathiriya, Milapkumar Kakadiya, Vinay Boghara, Anirbid Sircar, Shuchen ThakoreAbstract:Condensers are extensively used in refrigeration, air-conditioning and power generation systems. Condenser for the solar assisted geothermal cooling system is designed by using software simulation of condenser’s geometrical and flow parameters. The geothermal cooling system is designed to reduce electricity consumption of compressor during peak hours during the summer period in hot weather condition. The subsurface temperature of the earth around 5–6-m depth is fairly constant throughout the year which fulfills the requirement of cooling inside the building or residence by using water as a heat exchanging medium. Water is circulated in closed loop system buried into subsurface which sinks the heat of refrigerant from condenser inside the subsurface soil. The condenser is designed by comparing results obtained from (1) manual calculation (2) simulation by CHEMCAD software. In order to have a good and optimized design, manual and software-based calculations should be carried out simultaneously and verified with each other. It is found that results obtained from both calculations are approximately same with a minor difference. The geometry and flow parameter of the condenser is determined on the basis of surrounding temperature. The solar panel is used for power generation to reduce electricity consumption by the compressor, pump, and evaporator fan coil. This provides the hybrid solar assisted geothermal cooling system.
V. S. Krylov - One of the best experts on this subject based on the ideXlab platform.
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Numerical Simulation of Steam Condensation in a Steam-Gas Mixture Flow in a Variable-Section Channel with a Bundle of Smooth Horizontal Tubes
Thermal Engineering, 2019Co-Authors: K. B. Minko, V. I. Artemov, G. G. Yan’kov, V. S. KrylovAbstract:In this paper, the results from calculations of heat and mass transfer in a variable-cross-section channel with a bundle of smooth horizontal tubes, on the surface of which steam from a moving steam-gas mixture (SGM) condenses, are presented. The decrease in the channel’s cross section and, accordingly, the number of tubes in the vertical rows along the SGM movement provides the mixture with approximately constant velocity as the steam condenses. The mathematical model used in this study is described in detail in our previous publications. The two-dimensional equations of single-phase hydrodynamics, energy, and diffusion are solved for the external SGM flow. The condensation process is modeled at the level of the boundary conditions on the tube surface, taking into account a moving laminar condensate film. The heat transfer through the tube wall from the film to the cooling water is described using a one-dimensional model of the wall. To account for the irrigation of the bundle’s lower tubes with condensate formed on the upper tubes (inundation effect), a simplified model is used. The data on the velocity fields and impurity concentration in the condenser and the heat transfer characteristics are presented. The calculation results of the heat transfer coefficients on the tubes of the first vertical row of the bundle and the heat transfer coefficients for individual sections of the simulated condenser containing several tube rows at a 0–8.5% volume fraction of air in the SGM at the inlet to the apparatus are compared with experimental data. A quite satisfactory agreement between the calculated and experimental data is obtained, which confirms the efficiency of the used model. The calculated data on the local velocity fields and the composition of the steam-air mixture indicate a significant heterogeneity of these characteristics. This complicates the development of relatively simple engineering methods for calculating the heat load of Condensers at high air concentrations. The calculations were performed using in-house CFD-code ANES.
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Investigation of Parallel Operation of Vacuum Condenser Sections with Nonuniform Cooling
Thermal Engineering, 2019Co-Authors: O. O. Milman, A. Yu. Kartuesova, G. G. Yankov, A. V. Ptakhin, V. S. Krylov, M. O. KorlyakovaAbstract:Vacuum Condensers for steam turbines are usually designed at design conditions when all condenser sections are cooled identically with the flowrate of cooling water (or air for air-cooled Condensers) and the same air inleakage in each section. A deviation from the design operating conditions occurs due to several causes, such as nonuniform cooling of the condenser heat transfer surface because of its fouling or a fan failure (in air-cooled Condensers) and local air inleakage. To investigate condensation under nonuniform cooling conditions, a test facility simulating a condenser was constructed. It consists of two parallel channels. Nonuniformity of cooling in one of the channels was simulated by reducing the cooling water flow. There were regimes with steam feeding into air to model air inleakage occurring in actual condensing units. The experiments were performed in the condensation pressure range of p _c = 8–20 kPa. The previous predictions suggest that installation of orifices with a low-pressure drop can reduce the condenser pressure in case of nonuniform cooling. The effect of orifices with different diameters on the condensation process parameters was studied in this test facility. It has been demonstrated that installation of the orifices facilitates a decrease in the condenser pressure with a cooling water flow rate through one of the channels less than 50% of the design value. A range of optimal orifice diameters for this experimental condenser model was determined. According to the experiments, the benefit of orifice installation is observed only in case of joint operation of the condenser with a volumetric degasser, such as a steam jet ejector. The experimental data demonstrate an increase in the efficiency of joint operation of a condenser and an ejector under nonuniform cooling conditions due to installation of orifices in the line of steam-air mixture ejection.
O. O. Milman - One of the best experts on this subject based on the ideXlab platform.
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Investigation of Parallel Operation of Vacuum Condenser Sections with Nonuniform Cooling
Thermal Engineering, 2019Co-Authors: O. O. Milman, A. Yu. Kartuesova, G. G. Yankov, A. V. Ptakhin, V. S. Krylov, M. O. KorlyakovaAbstract:Vacuum Condensers for steam turbines are usually designed at design conditions when all condenser sections are cooled identically with the flowrate of cooling water (or air for air-cooled Condensers) and the same air inleakage in each section. A deviation from the design operating conditions occurs due to several causes, such as nonuniform cooling of the condenser heat transfer surface because of its fouling or a fan failure (in air-cooled Condensers) and local air inleakage. To investigate condensation under nonuniform cooling conditions, a test facility simulating a condenser was constructed. It consists of two parallel channels. Nonuniformity of cooling in one of the channels was simulated by reducing the cooling water flow. There were regimes with steam feeding into air to model air inleakage occurring in actual condensing units. The experiments were performed in the condensation pressure range of p _c = 8–20 kPa. The previous predictions suggest that installation of orifices with a low-pressure drop can reduce the condenser pressure in case of nonuniform cooling. The effect of orifices with different diameters on the condensation process parameters was studied in this test facility. It has been demonstrated that installation of the orifices facilitates a decrease in the condenser pressure with a cooling water flow rate through one of the channels less than 50% of the design value. A range of optimal orifice diameters for this experimental condenser model was determined. According to the experiments, the benefit of orifice installation is observed only in case of joint operation of the condenser with a volumetric degasser, such as a steam jet ejector. The experimental data demonstrate an increase in the efficiency of joint operation of a condenser and an ejector under nonuniform cooling conditions due to installation of orifices in the line of steam-air mixture ejection.
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Design and layout characteristics of steam turbine Condensers
Thermal Engineering, 2014Co-Authors: V. A. Fedorov, O. O. MilmanAbstract:We present the results of investigations carried out during the development of steam turbine condensing systems comprising a condenser, an air removing device, and condensate and circulation systems. It is found that the tube bundle layout and the characteristics of devices for removing noncondensable gases have an essential effect on the heat transfer intensity and pressure in the Condensers. The design of the heat-transfer surface of a condenser operating with constant velocity of steam during its condensation is described, and the procedure for calculating the area and configuration of such heat-transfer surface is outlined. Results from tests of such apparatuses are presented. It is shown that the heat-transfer coefficients in them are a factor of 1.5–3.0 higher than those in the existing Condensers at a moderate velocity of cooling medium. A qualitative pattern of a change in the volume filled with noncondensable gases that occurs during a decrease of thermal load or drop of cooling medium temperature is shown taking as an example Condensers with steam flowing inside the condenser tubes.
L J Yang - One of the best experts on this subject based on the ideXlab platform.
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trapezoidal array of air cooled Condensers to restrain the adverse impacts of ambient winds in a power plant
Applied Energy, 2012Co-Authors: L J Yang, M H Wang, Yanru YangAbstract:Ambient winds may deteriorate the thermo-flow performances of air-cooled Condensers, so it is of use to take measures against the adverse impacts of winds upon the air-cooled Condensers in a power plant. On the basis of a 2×600MW direct dry cooling power plant, a new trapezoidal array of air-cooled Condensers is proposed. The computational models of the air-side fluid and heat flows of the air-cooled Condensers in a trapezoidal array at various wind speeds and in various wind directions are developed, and the velocity and temperature fields are presented by using CFD simulations. The volumetric flow rate, inlet air temperature and heat rejection for different condenser cells are obtained and compared with those of the current air-cooled Condensers in the rectangular array. The results show that the reversed flows arose in the upwind condenser cells at high wind speeds disappear due to the trapezoidal array of air-cooled Condensers, resulting in a lowered inlet air temperature and an increased heat rejection of the upwind condenser cells. The hot plume recirculation in the wind direction of 0° becomes very weak and only appears at one side near the main buildings. The thermo-flow performances are improved to a certain extent thanks to the trapezoidal array of air-cooled Condensers. It is recommended that air-cooled Condensers in a power plant take the form of trapezoidal array to restrain the adverse impacts of ambient winds.
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wind effect on the thermo flow performances and its decay characteristics for air cooled Condensers in a power plant
International Journal of Thermal Sciences, 2012Co-Authors: L J Yang, Yanru YangAbstract:Abstract Ambient wind plays important roles in the thermo-flow performances of air-cooled Condensers, but the wind effect mainly imposes on the upwind and bilateral condenser cells and will decay immediately. It is of benefit to the design and operation optimization of air-cooled Condensers in a power plant to investigate the wind effect and its decay characteristics. On the basis of a representative 2 × 600 MW direct dry cooling power plant, the physical and mathematical models of the air-side fluid and heat flows for the air-cooled Condensers at various ambient wind speeds and directions are set up. The velocity and temperature fields are presented and the volumetric flow rate, inlet air temperature and heat rejection for different condenser cells are obtained by using CFD simulation. The results show that the reversed flows happened in the upwind condenser cells lead to the high inlet air temperature, worsening the cooling capability of air at high wind speeds. Due to the combined behavior of hot plume discharge and ambient wind, the wind effect decays rapidly along the wind direction. At the wind direction of 90°, the deficiencies of the thermo-flow performances of air-cooled Condensers are mainly resulted from the flow rate decrease of the upwind condenser cells, not the hot plume recirculation. The hot plume recirculation flows play adverse roles in deteriorating the performances of air-cooled Condensers at the wind direction of 0°.
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space characteristics of the thermal performance for air cooled Condensers at ambient winds
International Journal of Heat and Mass Transfer, 2011Co-Authors: L J Yang, Yang YangAbstract:Abstract Ambient winds may lead to poor fan performance, exhaust air recirculation and mal-distribution of the air across the tube bundles of the air-cooled Condensers in a power plant. Investigations of the impacts of the ambient winds on the air-cooled Condensers are key area of focus. Based on a representative 2 × 600 MW direct dry cooling power plant, the physical and mathematical models of the air-side fluid and heat flow in the air-cooled Condensers at various ambient wind speeds and directions are set up by introducing the radiator model to the fin-tube bundles. The volumetric flow rate, inlet air temperature and heat rejection for different air-cooled Condensers as a whole, condenser cells and fin-tube bundles are obtained by using CFD simulation. The results show that the thermo-flow performances for the air-cooled condenser as a whole, condenser cells and heat exchanger bundles vary widely in space. The thermal performances of the air-cooled Condensers, condenser cells and fin-tube bundles at the downstream are generally superior to those at the upwind. It is of use for the upwind fan regulations and the A-frame condenser cell geometric optimization to investigate the space characteristics of the thermal performance for the air-cooled Condensers in a power plant.
Manan Shah - One of the best experts on this subject based on the ideXlab platform.
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Model design of condenser for solar assisted geothermal cooling system using software simulation
Modeling Earth Systems and Environment, 2019Co-Authors: Manan Shah, Harshil Kathiriya, Milapkumar Kakadiya, Vinay Boghara, Anirbid Sircar, Shuchen ThakoreAbstract:Condensers are extensively used in refrigeration, air-conditioning and power generation systems. Condenser for the solar assisted geothermal cooling system is designed by using software simulation of condenser’s geometrical and flow parameters. The geothermal cooling system is designed to reduce electricity consumption of compressor during peak hours during the summer period in hot weather condition. The subsurface temperature of the earth around 5–6-m depth is fairly constant throughout the year which fulfills the requirement of cooling inside the building or residence by using water as a heat exchanging medium. Water is circulated in closed loop system buried into subsurface which sinks the heat of refrigerant from condenser inside the subsurface soil. The condenser is designed by comparing results obtained from (1) manual calculation (2) simulation by CHEMCAD software. In order to have a good and optimized design, manual and software-based calculations should be carried out simultaneously and verified with each other. It is found that results obtained from both calculations are approximately same with a minor difference. The geometry and flow parameter of the condenser is determined on the basis of surrounding temperature. The solar panel is used for power generation to reduce electricity consumption by the compressor, pump, and evaporator fan coil. This provides the hybrid solar assisted geothermal cooling system.
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Model design of condenser for solar assisted geothermal cooling system using software simulation
Modeling Earth Systems and Environment, 2019Co-Authors: Manan Shah, Harshil Kathiriya, Milapkumar Kakadiya, Vinay Boghara, Anirbid Sircar, Shuchen ThakoreAbstract:Condensers are extensively used in refrigeration, air-conditioning and power generation systems. Condenser for the solar assisted geothermal cooling system is designed by using software simulation of condenser’s geometrical and flow parameters. The geothermal cooling system is designed to reduce electricity consumption of compressor during peak hours during the summer period in hot weather condition. The subsurface temperature of the earth around 5–6-m depth is fairly constant throughout the year which fulfills the requirement of cooling inside the building or residence by using water as a heat exchanging medium. Water is circulated in closed loop system buried into subsurface which sinks the heat of refrigerant from condenser inside the subsurface soil. The condenser is designed by comparing results obtained from (1) manual calculation (2) simulation by CHEMCAD software. In order to have a good and optimized design, manual and software-based calculations should be carried out simultaneously and verified with each other. It is found that results obtained from both calculations are approximately same with a minor difference. The geometry and flow parameter of the condenser is determined on the basis of surrounding temperature. The solar panel is used for power generation to reduce electricity consumption by the compressor, pump, and evaporator fan coil. This provides the hybrid solar assisted geothermal cooling system.