scholarly journals Analysis of the possibility of utilization of waste heat from the marine engine in the ORC power plant

2018 ◽  
Vol 70 ◽  
pp. 01006
Author(s):  
Radomir Kaczmarek ◽  
Aleksander Stachel

Modern marine diesel engines are characterized by ~50% conversion of chemical energy of fuel into useful work. The remaining amount of heat is lost to the environment as the so-called waste heat, whereby its part can be used in various marine heating installations. In the ship's engine the biggest source of waste heat, potentially useful for further use, both due to the amount of available energy and its quality, are exhaust emissions from the main engine. Taking into account the need for rational energy management, the paper presents a preliminary analysis and assessment of the possibility of using the heat of hot exhaust gases to generate electricity in the so-called low-temperature ORC installation. Based on the available data, the operation of ORC installation has been evaluated, taking into account the influence of engine operating parameters on the obtained electrical power and the cycle efficiency. The aim of the analysis was to demonstrate that there is a real possibility to use the waste heat from marine engine exhausts to drive the ORC and generate electricity.

2021 ◽  
Vol 13 (2) ◽  
pp. 693
Author(s):  
Elnaz Azizi ◽  
Mohammad T. H. Beheshti ◽  
Sadegh Bolouki

Nowadays, energy management aims to propose different strategies to utilize available energy resources, resulting in sustainability of energy systems and development of smart sustainable cities. As an effective approach toward energy management, non-intrusive load monitoring (NILM), aims to infer the power profiles of appliances from the aggregated power signal via purely analytical methods. Existing NILM methods are susceptible to various issues such as the noise and transient spikes of the power signal, overshoots at the mode transition times, close consumption values by different appliances, and unavailability of a large training dataset. This paper proposes a novel event-based NILM classification algorithm mitigating these issues. The proposed algorithm (i) filters power signals and accurately detects all events; (ii) extracts specific features of appliances, such as operation modes and their respective power intervals, from their power signals in the training dataset; and (iii) labels with high accuracy each detected event of the aggregated signal with an appliance mode transition. The algorithm is validated using REDD with the results showing its effectiveness to accurately disaggregate low-frequency measured data by existing smart meters.


Author(s):  
W Gu ◽  
Y Weng ◽  
Y Wang ◽  
B Zheng

This article describes and evaluates an organic Rankine cycle (ORC) for a waste heat recovery system by both theoretical and experimental studies. Theoretical analysis of several working fluids shows that cycle efficiency is very sensitive to evaporating pressure, but insensitive to expander inlet temperature. Second law analysis was carried out using R600a as a working fluid and a flow of hot air as a heat source, which is not isothermal, along the evaporator. The result discloses that the evaporator's internal and external entropy generation is the main source of total entropy generation. The effect of the heat source temperature, evaporating pressure, and evaporator size on the entropy generation rate is also presented. The obtained useful power is directly linked to the total entropy generation rate according to the Gouy—Stodola theorem. The ORC testing system was established and operated using R600a as a working fluid and hot water as a heat source. The maximum cycle efficiency of the testing system is 5.2 per cent, and the testing result also proves that cycle efficiency is insensitive to heat source temperature, but sensitive to evaporating pressure. The entropy result also shows that internal and external entropy of the evaporator is the main source of total entropy generation.


2015 ◽  
Vol 787 ◽  
pp. 782-786 ◽  
Author(s):  
R. Prakash ◽  
D. Christopher ◽  
K. Kumarrathinam

The prime objective of this paper is to present the details of a thermoelectric waste heat energy recovery system for automobiles, more specifically, the surface heat available in the silencer. The key is to directly convert the surface heat energy from automotive waste heat to electrical energy using a thermoelectric generator, which is then regulated by a DC–DC Cuk converter to charge a battery using maximum power point tracking. Hence, the electrical power stored in the battery can be maximized. Also the other face of the TEG will remain cold. Hence the skin burn out accidents can be avoided. The experimental results demonstrate that the proposed system can work well under different working conditions, and is promising for automotive industry.


Author(s):  
Salman Abdu ◽  
Song Zhou ◽  
Malachy Orji

Highly increased fuel prices and the need for greenhouse emissions reduction from diesel engines used in marine engines in compliance with International Maritime Organization (IMO) on the strict regulations and guidelines for the Energy Efficiency Design Index (EEDI) make diesel engine exhaust gas heat recovery technologies attractive. The recovery and utilization of waste heat not only conserves fuel, but also reduces the amount of waste heat and greenhouse gases dumped to the environment .The present paper deals with the use of exergy as an efficient tool to measure the quantity and quality of energy extracted from waste heat exhaust gases in a marine diesel engine. This analysis is utilized to identify the sources of losses in useful energy within the components of the system for three different configurations of waste heat recovery system considered. The second law efficiency and the exergy destroyed of the components are investigated to show the performance of the system in order to select the most efficient waste heat recovery system. The effects of ambient temperature are also investigated in order to see how the system performance changes with the change of ambient temperature. The results of the analysis show that in all of the three different cases the boiler is the main source of exergy destruction and the site of dominant irreversibility in the whole system it accounts alone for (31-52%) of losses in the system followed by steam turbine and gas turbine each accounting for 13.5-27.5% and 5.5-15% respectively. Case 1 waste heat recovery system has the highest exergetic efficiency and case 3 has the least exergetic efficiency.


Synthesis ◽  
2018 ◽  
Vol 50 (19) ◽  
pp. 3833-3842 ◽  
Author(s):  
Vladimir Dimitrov ◽  
Simon Woodward

Electrically conducting organic salts, known for over 60 years, have recently demonstrated new abilities to convert waste heat directly into electrical power via the thermoelectric effect. Multiple opportunities are emerging for new structure–property relationships and for new materials to be obtained through synthetic organic chemistry. This review highlights key aspects of this field, which is complementary to current efforts based on polymeric, nanostructured or inorganic thermoelectric materials and indicates opportunities whereby mainstream organic chemists can contribute.1 What Are Thermoelectrics? And Why Use Them?2 Current Organic and Hybrid Thermoelectrics3 Unique Materials from Tetrathiotetracenes4 Synthesis of Tetrathiotetracenes5 Materials and Device Applications6 Future Perspectives


2021 ◽  
Author(s):  
Elias A. Yfantis ◽  
Efthymios G. Pariotis ◽  
Theodoros C. Zannis ◽  
Konstantina Asimakopoulou

The energy and the exergy performance of a dual-loop Organic Rankine Cycle (ORC), which harvests exhaust heat from a two-stroke slow-speed main marine diesel engine of a bulk carrier is examined herein. An energy analysis is adopted to calculate the energy flows to the components of the high-temperature (HT) and the low-temperature (LT) loops of the bottoming ORC and through them, to calculate the energy efficiency of the ORC and the generated power from both expanders. Also, an exergy analysis is implemented to predict the irreversibility rates of the components of both HT and LT loops of the ORC system. Various organic fluids are examined for the HT and the LT ORC loops and the optimum combination is selected based on the results of a parametric analysis. The effect of ambient conditions on the energetic and exergetic performance of the dual-loop ORC is examined. The energy analysis of the bottoming dual-loop ORC is projected to a specific mission operational profile of a bulk carrier for predicting the benefits in fuel cost saving and CO2 and SO2 emission reduction compared to conventional vessel operation.


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