Simulation of indoor comfort level in a building cooled by a cooling tower–concrete core cooling system under hot–semiarid climatic conditions

2016 ◽  
Vol 26 (5) ◽  
pp. 680-693 ◽  
Author(s):  
D. G. Leo Samuel ◽  
S. M. Shiva Nagendra ◽  
M. P. Maiya
Keyword(s):  
Indoor Air ◽  
Cooling Tower ◽  
Cooling System ◽  
Fluid Dynamic ◽  
Climatic Conditions ◽  
Comfort Level ◽  
Passive Cooling ◽  
Computational Fluid Dynamic Analysis ◽  
Concrete Core ◽  
Core Cooling

Concrete core cooling system is an energy efficient alternative to the conventional mechanical cooling system. It provides better comfort due to direct absorption of radiation load, low indoor air velocity, apt vertical temperature gradient and absence of noise. It can be operated at relatively higher water temperature, which facilitates the use of passive cooling strategies. In this study, a cooling tower, which is an ‘evaporative cooling system’, is preferred over other passive cooling options due to its better cooling performance in dry regions and its ability to operate all through the day. This paper presents the results of computational fluid dynamic analysis of a room cooled by concrete core cooling system supported by a cooling tower. The study reveals that for a typical hot–semiarid summer climatic condition in India, the system reduces the average indoor air temperature to a comfortable range of 23.5 to 28℃ from an uncomfortable range of 35.3 to 41℃ in a building without cooling. The average predicted percentage of dissatisfied falls from 99.7% in a building without cooling, to 37.3% if roof and floor of a building are cooled with concrete core cooling system and further to 6.3% if all surfaces are cooled with concrete core cooling system.

Performance Analysis of Wind Tower Greenhouse Integration Using CFD

2020 ◽  
Author(s):  
Muhammad Sajjad ◽  
MD Islam ◽  
Isam Janajreh
Keyword(s):  
Performance Analysis ◽  
Relative Humidity ◽  
Flow Rate ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Water Mist ◽  
Climatic Conditions ◽  
Computational Fluid Dynamic Analysis ◽  
Multiple Species ◽  
Air Flow Velocity

Abstract The current study investigates the effect of wind catcher-greenhouse integration on the micro-climatic conditions inside the green house. The potential application of wind tower in greenhouse systems for hot climatic conditions with water mist injection was carefully evaluated. The effect of various parameters such as air flow velocity, relative humidity, injector mass flow rate and injector position in the wind tower was studied. The variations in the temperature and relative humidity was observed in the greenhouse. The computational fluid dynamic analysis was carried out using Fluent and k-ε turbulence model was adopted for the analysis. A non-isothermal, multiple species, viscous and turbulent flow is pursued. It was observed that the addition of water injectors inside the wind catcher significantly reduced the temperature and enhanced the relative humidity of the air.

Fog harvesting from cooling towers using metal mesh: Effects of aerodynamic, deposition, and drainage efficiencies

2019 ◽  
Vol 234 (7) ◽  
pp. 994-1014 ◽  
Author(s):  
Ritwick Ghosh ◽  
Ranjan Ganguly
Keyword(s):  
Fresh Water ◽  
Cooling Tower ◽  
Collection Efficiency ◽  
Fluid Dynamic ◽  
Tangential Velocity ◽  
Cooling Towers ◽  
Metal Mesh ◽  
Computational Fluid Dynamic Analysis ◽  
Fog Collection ◽  
Energy Penalty

Fog harvesting is recognized as an important alternate source of fresh water. Industrial fog can supplement water for industrial requirement. Collection of fog (drift droplets) from cooling tower plumes is a viable mode of industrial fog harvesting. The present study delves deeper into the findings of our earlier pilot investigation, on cooling tower fog harvesting and unravels how the collection efficiency depends on interaction of the mesh with the oncoming flow and the deposited fog droplets. Herein, we quantify the fog collection and explain the rationale of the individual contributions of aerodynamic, deposition, and drainage efficiencies on the overall collection efficiency. The effect of the mesh orientations and the tangential velocity component of the cooling tower plume (arising out of the cooling tower-fan rotation) are considered. Aerodynamic efficiency of the mesh and pressure drop across is estimated through computational fluid dynamic analysis. Also, an analysis of the force interaction between the mesh wires, deposited droplet, and the fog stream is carried out to identify the salient deterring factors like re-entrainment, clogging, and premature dripping of collected water droplets, based on which the regime of collection is mapped. The best collection configuration is found at an inclination of 15° with the vertical, with an overall collection efficiency of about 16%. The best configuration would allow recovery of re-usable fresh water at a nominal energy penalty of ∼3.9 kWh/m3. Our results offer the design bases for developing full-scale fog harvesting setups for industrial cooling towers.

Energy Saving Potential of a Combined Solar and Natural Gas-Assisted Vapor Absorption Building Cooling System

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Gaurav Singh ◽  
Ranjan Das
Keyword(s):  
Natural Gas ◽  
Energy Savings ◽  
Cooling System ◽  
Electric Energy ◽  
High Capacity ◽  
Climatic Conditions ◽  
Comfort Level ◽  
Coefficient Of Performance ◽  
Electric Energy Consumption ◽  
Vapor Absorption

A building energy simulation study is carried out to analyze the performance of a triple-hybrid single-effect vapor absorption cooling system (VACS) operated by solar, natural gas, and auxiliary electricity-based cogeneration. A high capacity small office building subjected to different climatic conditions is considered. The system is designed to continuously maintain a specified building comfort level throughout the year under diverse environmental conditions. Simulations are done at different generator temperatures to investigate the performance in terms of total annual electric energy consumption, heating energy, and the coefficient of performance (COP). The performance of the present VACS is compared with the conventional compression-based system, which demonstrates the electric energy and cost saving potentials of the proposed VACS. Simulation outcomes are well-validated against benchmark data from national renewable energy laboratory and energy conservation building code. Interestingly, it is found that beyond a certain collector area, surplus energy savings can be acquired with the present triple-hybrid VACS as compared to the compression-based cooling. Results also show that COP of the simulated system is in line with experimental values available in the literature. Finally, recommendations are given to operate the complete system on solar and biomass resources, which provide encouraging opportunity for agriculture-based countries.

Computational Fluid Dynamic Analysis for Modified Steam Duct in Air Cooled Condenser

2011 ◽  
Vol 110-116 ◽  
pp. 4246-4254
Author(s):  
Fatemehsadat Salehi ◽  
Ramin Haghighi Khoshkho
Keyword(s):  
Pressure Drop ◽  
Computational Fluid Dynamic ◽  
Power Plants ◽  
Cooling System ◽  
Tube Bundle ◽  
Fluid Dynamic ◽  
Steam Flow ◽  
Computational Fluid Dynamic Analysis ◽  
Velocity Form ◽  
Turbine Exhaust

Cooling system is a subsystem of a power plan that has an indispensable effect on efficiency of power plant. Air Cooled Condenser (ACC) system as a cooling system, is usually used in many power plants. Steam duct as a part of ACC conveys the steam flow with high velocity form steam turbine exhaust to head of tube bundle which is located at height of 25 to 30 meters. In this paper, pressure drop in steam duct is calculated using computational fluid dynamic method. Then, in order decrease pressure drop and consequently increase ACC efficiency, steam duct configuration is modified. The steam flow is modeled as an incompressible, turbulent and single phase flow. The solution strategy is based on SIMPLE and Segregated Implicit algorithm and the k-ε RNG model for turbulence are employed. The second order upwind differencing scheme are applied to discrete governing equations. Numerical results confirm reducing of total pressure drop in modified diffuser comparing with primary geometry.

Impact of roof shading on building energy performance in warm & humid climatic places of India

2020 ◽  
pp. 50-64
Author(s):  
Kuladeep Kumar Sadevi ◽  
Avlokita Agrawal
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Performance ◽  
General Assumption ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Passive Cooling ◽  
Base Case ◽  
U Value ◽  
The Impact

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.

Sign in / Sign up

Export Citation Format

Share Document