Design and development of refrigerator using PCM based heat exchanger
Devendra Danotiya, Nitin D banker
June, 2014 -
Successfully implemented PCM based heat exchanger in a domestic refrigerator.
This was able to have ~ 15% of energy saving.
The Compressor exit temperature was lower for PCM condenser which will benefit the compressor life.
Numerical modeling of the PCM based heat exchanger also has been performed and compared with experimental results.
AN IMPROVED GAS TURBINE POWER PLANT (201811042871)
Inventors: Dr. Nitin D Banker, Dr. Devendra Singh Dandotiya. Filed November 14, 2018 in India
AN ENERGY EFFICIENT AIR CONDITIONING SYSTEM AND METHOD THEREOF (201811041530)
Inventors: Dr. Nitin D Banker, Dr. Devendra Singh Dandotiya. Filed November 02, 2018 in India
Performance Enhancement of a Refrigerator using Phase Change Material based Condenser: An Experimental Investigation
Published by (International Journal of Air-Conditioning and Refrigeration)
Authors: Devendra Dandotiya, Nitin D banker. Published November 09, 2017
Tropical countries like India, the ambient temperature reaches to 45–50 C in the summer and higher ambient temperature directly impacts the energy required by the household refrigerator. This paper presents an experimental performance of a domestic refrigerator incorporated with a phase change material (PCM)-based condenser in parallel to the conventional wire-and-tube air-cooled condenser for the climatic conditions of India. It is proposed to operate the refrigerator with the PCM-based condenser, while the ambient temperature is higher during the day, otherwise with the air-cooled condenser. Due to large latent heat storage capacity of the PCM, the condenser temperature would not increase significantly. The COP of the PCM-based condenser was 28% higher as compared to an air-cooled condenser for 60 min which reduces to 3 % as the PCM temperature reached to 33 C. The energy consumption is lower by ∼15% in of refrigerator experimentation with the proposed modification.
Numerical investigation of heat transfer enhancement in a multitube thermal energy storage heat exchanger using fins
Published by (Numerical Heat Transfer, Part A: Applications)
Authors: Devendra Dandotiya, Nitin D Banker. Published September 25, 2017
The application of a phase change material (PCM) as thermal energy storage observed unprecedented growth due to its large latent heat storage capacity at a constant temperature. However, the design of an energy storage heat exchanger is a challenging task because of the poor thermal conductivity of PCMs. In an effort to improve the heat exchanger design, this paper presents a numerical performance investigation of a PCM-based multitube heat exchanger incorporated with two new fin configurations. The analysis of the results shows that the placement of fins is one of the important aspects, which needs to be cogitated in the design of heat exchangers.
Gas Turbine Inlet Air Cooling Using Vapor-Adsorption Refrigeration Driven by Power Plant Exhaust
Published by (ASME Gas Turbine India Conference 2017)
Authors: varuneswara reddy panayam, Devendra Dandotiya, nnITIN d bANKER. Published December 07, 2017
Turbine inlet air cooling (TIAC) has long been the most commonly used method to improve the performance of gas turbine based power plants. It is particularly effective in regions with high ambient temperatures. With growing energy demands and higher ambient temperatures around the globe, it is important to look beyond cooling cycles like vapor-absorption and vapor-compression which have certain limitations. It is prudent to use a vapor-adsorption cycle for TIAC since the exhaust heat will be used as the power source for adsorption compressor, ultimately increasing efficiency of the power plant. Also, the scalability of adsorption cooling from mere Watts to hundreds of kW and its ability to function using lower temperature heat sources (as low as 60 degree Celsius) render it highly suitable for TIAC. In this work, a gas turbine power plant and a TIAC system running on vapor-adsorption cycle are mathematically modeled. Thermal analysis involving comparison of performance of the chiller and power plant with and without inlet air cooling at varying ambient and desorption temperatures is presented. Performance parameters analyzed include net power output of the power plant, PER and the COP of the chiller. The results show that vapor-adsorption system has huge potential to be integrated with gas turbine power plant for inlet air cooling.
Performance Improvement of Gas Turbine Power Plant by Intake Air Passive Cooling using Phase Change Material based Heat
Published by (ASME Gas Turbine India Conference 2017)
Authors: Devendra Dandotiya, Nitin D Banker. Published December 07, 2017
The power output of a gas turbine plant decreases with the increase in ambient temperature. Moreover, the ambient temperature fluctuates about 15 20°C in a day. Hence, cooling of intake air makes a noticeable improvement to the gas turbine performance. In this regard, various active cooling techniques such as vapor compression refrigeration, vapor absorption refrigeration, vapor adsorption refrigeration and evaporative cooling are applied for the cooling of intake air. This paper presents a new passive cooling technique where the intake air temperature is reduced by incorporating phase change material (PCM) based heat exchanger parallel to conventional air intake line. During the daytime, the air is passed through the PCM which has melting temperature lower than the peak ambient temperature. This will reduce the ambient air temperature before taking to the compressor. Once the PCM melts completely, the required ambient air would be drawn from the ambient through conventional air intake arrangement. During the night, when there is lower ambient temperature, PCM converts from liquid to solid. The selected PCM has a melting temperature less than the peak ambient temperature and higher than the minimum ambient temperature. It is observed from the numerical modeling of the PCM that about 4 hours are required for the melting of PCM and the intake air also can be cooled by 5 °C for this much time. The thermodynamic analysis of the results showed about 5.2% improvement in net power output and thermal efficiency, each for four hours at an ambient temperature of 45°C.
Performance Enhancement of a Single Door Domestic Refrigerator by Incorporating Section Doors inside Refrigerated Space
Published by (Proceedings of the 12th International Conference on Thermal Engineering: Theory and Applications (IC)
Authors: Dandotiya, D. and Banker N.D.. Published February 25, 2019
Remaining Useful Life Predictions for Turbofan Engine Degradation Using Online Long Short-Term Memory Network
Published by ( ASME)
Authors: Pallabi Kakati, Devendra Dandotiya, Bhaskar Pal. Published December 06, 2019
In any industrial system, accurate prediction of Remaining Useful Life (RUL) is important for Prognostics and Health Management (PHM), so as to detect breakdown of system well in advance and take proper measures. Different methods are available in the literature that have been proposed for prediction of RUL. Among these methods, the data driven method is accepted to be the most reliable by many researchers, due to the use of real time sensor based vibrational and/or pressure data. These data are acquired in time domain. Methods such as Recurrent Neural Networks (RNNs), Convolutional Neural Network (CNN), Hidden Markov Models (HMMs) are generally applied in this area. Nevertheless, all these methods have issues while dealing with dependencies in these data. In this context, Long Short-Term Memory (LSTM) neural network has been proposed to deal with these dependencies while predicting RUL of any system. The LSTM model has the advantage of retaining time domain information for a long duration of time. However, with the arrival of new data, the model needs to be updated. In this regard, a new online method based on LSTM network is proposed in this paper. The use of online technique offers us to retrain the model as new data arrives, which helps in improving the accuracy of the estimated RUL. To illustrate the application of the proposed online LSTM method, we have used the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) turbofan dataset. The results show an improved efficiency compared to the previously proposed methods for RUL estimation.
Online Automatic Degradation Diagnosis of Gas Turbine Bearings Based on Unsupervised Machine Learning
Published by (ASME GT INDIA 2019)
Authors: Pallabi Kakati, Devendra Dandotiya, Rajendrakumar Savanur. Published December 06, 2019
The bearing prognostic analysis plays a critical role in improving the reliability of any rotational engine. In data-driven methods, used in such bearing prognosis, real time bearing vibrational data can be acquired from a set of sensors. In literature, many supervised learning techniques have been proposed to analyze this data. However, the labelled training data required for such a supervised technique is not always available in real life. Therefore, in this work, an unsupervised learning technique based on adaptive resonance theory 2 (ART2) has been used for bearing vibrational signal analysis. The benefit of this method is that no separate training is required for the prognosis purpose. The gas turbine is studied in this work is a GE MS 3002 used in natural gas transportation in Algeria. This method is used to study the bearing vibrational signal emitted at the high-pressure turbine side. The use of online method helps us updating the model, as new observations are available. This method also offers better performance under noisy environment.
Energy and Exergy Analysis of a Gas Turbine Power Plant Integrated With Vapor Adsorption Refrigeration System
Published by (ASME)
Authors: Sanchit Agarwal, Darshika Gupta, Devendra Dandotiya, Nitin D. Banker. Published December 06, 2019
In the step towards the utilization of waste energy of Gas Turbine (GT) power plant exhaust gas, researchers have imposed adsorption refrigeration system over the absorption refrigeration due to several positive advantages. In the reported work, the system was analyzed based on first law efficiency. However, combining heat and work together for an evaluating system using first law efficiency would not provide a true picture of the performance of the system, whereas second law efficiency shows various irreversibilities associated with each component of the system and helpful in obtaining the optimum conversion of energy. In view of this, the presented paper studies performance analysis of GT power plant incorporated with the adsorption refrigeration system. Based on the parameters such as energy and exergetic efficiencies, cooling to power ratio and exergetic specific fuel consumption are considered for the system performance evaluation.
Theoretical Study of Energy Saving Through Redesign of Water Distribution Arrangement in a Medium-Rise Residential Build
Published by (J. Eng. Sustain. Bldgs. Cities.)
Authors: Devendra Dandotiya, Nitin D. Banker. Published July 09, 2020
The development of medium-rise buildings for the residence is the basic necessity to accommodate the growing population of countries like India where the residential land per capita is very small. Moreover, because of the energy shortage, energy-efficient development is the primary objective in the present scenario. With the efforts of reducing energy consumption in the medium-rise buildings, redesign of the water distribution system has been proposed in this study. In this proposed arrangement, two water pumps are placed at two different elevations, namely, ground and middle levels of the building. The first one at the ground level supplies water first to the middle floor flats and the second one at the intermediate level does for the middle to the top floor flats. Various building heights and pumps are studied theoretically and the analysis of the results shows that about 20% of the total pump energy can be saved by changing the way of water distribution in the residential buildings. Yet further energy-saving potential is available through the selection of better efficiency pumps. Moreover, reduction in pressure of the water at the lower floor flats is an additional advantage of the proposed arrangement.
Energy Efficiency Improvement of a Refrigerator Integrated With Phase Change Material-Based Condenser
Published by (J. Energy Resour. Technol.)
Authors: Devendra Dandotiya, Nitin D. Banker. Published November 19, 2020
Energy consumption of a household refrigerator majorly depends on the ambient temperature and is highest at the noontime and lowest at the night. To mitigate the impact of higher ambient temperature, condenser of the refrigerator is modified by incorporating phase change material (PCM) in it. This article presents the development of numerical model of the PCM-based condenser and its comparison with the experimental model. A 3D numerical model for a PCM, namely, FS21-based condenser has been developed in commercial software ansys fluent 16.2, and the simulation outcomes are compared with the experimental test results. A correlation of a coefficient of performance (COP) which is a function of PCM temperature has been proposed. Based on the developed numerical model and the correlation, two other PCM-based heat exchangers, RT25 and RT25HC, are also analyzed numerically and their PCM temperatures are predicted. At the end, COP of the refrigerator with each PCM is compared.
Evaluation of Minimum, Maximum and Optimum Source Temperature for Solar-Powered Adsorption Refrigeration System
Published by (Arabian Journal for Science and Engineering)
Authors: Nitin D. Banker, Devendra Dandotiya, Sai Vamsi Reddy Morthala, Mahesh Gaddam & Sridhar Kakileti . Published September 03, 2020
Due to the utilization of solar thermal energy and environmentally friendly nature, globally there is a huge thrust toward the development of vapor adsorption refrigeration systems. Indeed, it is necessary to identify the minimum, maximum and optimum temperatures of heat source for solar-powered adsorption systems. With this objective, the presented paper focuses on the evaluation of lower, upper and optimum temperatures of the heat source to run the adsorption refrigeration system. Performance parameters, cooling capacity and coefficient of performance (COP), have been utilized to derive the limits of source (desorption) temperatures and applied to two different adsorbent–adsorbate pairs, namely Maxsorb III–ethanol and Maxsorb III– R134a. The adsorption and evaporator temperatures considered for the analysis are 25–40 °C and − 10–10 °C, respectively.