scholarly journals Experimental tests of the prototypical micro-cogeneration system with a 100 kW biomass-fired boiler

2018 ◽  
Vol 70 ◽  
pp. 03014
Author(s):  
Krzysztof Sornek ◽  
Wojciech Goryl ◽  
Mariusz Filipowicz
Keyword(s):  
Heat Exchangers ◽  
Thermal Power ◽  
Experimental Tests ◽  
Rankine Cycle ◽  
Steam Pressure ◽  
Steam Engine ◽  
Steam Temperature ◽  
Power Generator ◽  
Cogeneration System ◽  
Shell And Tube

Renewable energy based micro cogeneration systems are an interesting option for domestic, agricultural and commercial sectors. In this paper, a dedicated system with a 100 kWth biomass-fired boiler was proposed. Developed system works according to modified Rankine Cycle operation. Steam generated in two shell and tube heat exchangers is used to power steam engine (connected with power generator) and then flows via condenser to degasifier. During the presented tests, the selected parameters of the boiler, oil circuit and steam/condensate circuit were analyzed. As was shown, the maximum thermal power taken from the oil circuit to evaporate condensate and superheat steam was ~105 kWth (it was ~91% of thermal power generated in the boiler). The value steam pressure varied from 2 to 5 bars during operation of the steam engine. Steam mass flow was then equal to ~105 kg/h, what allowed to generate electric power at a level of ~1.05 kWel. Such a low value resulted e.g. from limitations in the oil temperature, limitations in the steam temperature, steam pressure and steam flow, limitations caused by power generator’s construction, as well as other construction and operating parameters.

scholarly journals Biomass-powered micro cogeneration system based on the modified Rankine Cycle operation - the initial tests

2018 ◽  
Vol 49 ◽  
pp. 00105
Author(s):  
Krzysztof Sornek ◽  
Wojciech Goryl ◽  
Mariusz Filipowicz
Keyword(s):  
Rankine Cycle ◽  
Steam Engine ◽  
Power Generator ◽  
Tube Heat Exchanger ◽  
Whole Process ◽  
Medium Flow ◽  
Temperature Heat ◽  
Cogeneration System ◽  
Shell And Tube ◽  
Thermal Oil

This paper shows results of initial tests of prototypical microcogeneration system based on the modified Rankine cycle operation. This system is powered by a 100 kW straw-fired batch boiler which was adapted to operate as a high temperature heat source. Thermal oil, heated up to 190-200°C, transfers heat to two shell and tube heat exchangers (evaporator and superheater). Steam powers a 2-cylinder, double-acting, 20-horsepower steam engine. Then, it is condensed in a condenser (another shell and tube heat exchanger) and pumped to the degasser. Finally, condensate is pumped to the evaporator and the whole process starts again. The steam engine is connected with a power generator. The operation of the developed micro-cogeneration system is controlled by the control and measurement system based on WAGO PFC200 PLC controller. The following parameters are recording: temperature, pressure and medium flow (in the boiler, oil, steam and water circuits). The results of the initial tests are promising. Power generated in the system is actually about 1,0 kWel. Such power is sufficient for supplying a part of the system’s equipment. On the other hand, it is finally expected to ensure selfsufficient operation of the tested system.

Thermodynamics of James Watt – Ignored or not Understood?

2021 ◽  
Vol 42 (3) ◽  
pp. 397
Author(s):  
Jovan Mitrovic
Keyword(s):  
Latent Heat ◽  
Heat Engine ◽  
Primary Source ◽  
Rankine Cycle ◽  
Theoretical Work ◽  
Steam Pressure ◽  
Steam Engine ◽  
Saturated Steam ◽  
Maximum Efficiency ◽  
Starting Point

In the analysis of the development of thermodynamics as a science, the theoretical work of Sadi Carnot, published in 1824, is generally considered to be the starting point. Carnot studied the cycle of an ideal heat engine and formulated the condition for its maximum efficiency. In this article we examine James Watt’s contributions to the formation of fundamental concepts of thermodynamics, made in the course of his work on improving the Newcomen engine and developing his own steam engine. It is shown that Watt was the first to characterize thermodynamic properties such as latent heat and vapor density. The authors prove Watt’s priority in the studies of the dependence of saturated steam pressure on temperature, in which a critical point was found when the latent heat disappears. These results of Watt anticipated by many decades the studies on the thermodynamic critical state by Th. Andrews and J. Thomson. The article also discusses Wattʼs research on thermodynamic cycles. It is shown that he was the first to study the Rankine cycle with superheated steam, known from the history of thermodynamics. Watt was also the first scientist to introduce the concept of a steam engine’ volumetric work as the product of pressure and volume, and developed a device, the steam pressure indicator, to measure its value. We show the results obtained by Watt with steam to be considerably ahead of Prescott Jouleʼs work on the cooling and condensation of gases during expansion. The article presents an interpretation of Watt’s 1769 patent that is very important as the primary source for a subsequent study and establishment of the principles of energy conversion. The factual material presented in this article suggests that Watt’s scientific research have not been properly understood or simply went unnoticed.

Economic Analysis of a 660MW Supercritical Turbine for Steam Initial Parameters

2014 ◽  
Vol 960-961 ◽  
pp. 1550-1553 ◽  
Author(s):  
Yu Lin Tang ◽  
Shan Tu ◽  
Yang Du ◽  
Chao Wang ◽  
Hong Juan Wang
Keyword(s):  
Power Plant ◽  
Thermal Power ◽  
Steam Pressure ◽  
Heat Consumption ◽  
Operating Parameters ◽  
Steam Temperature ◽  
Operating Modes ◽  
Endothermic Process ◽  
Steam Parameters ◽  
Main Steam

Economic diagnosis of thermal power units is to determine the economy of its operating parameters and operating modes by quantitative and qualitative analysis, which is significant to economic operation and energy saving of power plant. On the basis of equivalent enthalpy drop method and the theory of variable conditions, the economic diagnosis model of operating parameters was established. As main steam temperature and main steam pressure for example, economic diagnosis of a 660MW supercritical steam turbine unit was performed. The result demonstrates that improving the main steam temperature or main steam pressure can reduce heat consumption of the unit. The essence of improving the initial steam parameters is to improve the average temperature of the steam cycle endothermic process, thus improving the circulation efficiency and reducing heat consumption. The economic impact of main steam temperature is up to 0.61g/(kW·h), while which of main steam pressure is little. Therefore, by increasing the initial steam parameters, especially the main steam temperature, to improve the economy of the entire power plant is the main way to enhance the efficiency of power plant in the current.

scholarly journals Modelling of Polymeric Shell and Tube Heat Exchangers for Low-Medium Temperature Geothermal Applications

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2737
Author(s):  
Francesca Ceglia ◽  
Adriano Macaluso ◽  
Elisa Marrasso ◽  
Maurizio Sasso ◽  
Laura Vanoli
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Power Plants ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Heat Transfer Area ◽  
Geothermal Fluid ◽  
Shell And Tube

Improvements in using geothermal sources can be attained through the installation of power plants taking advantage of low and medium enthalpy available in poorly exploited geothermal sites. Geothermal fluids at medium and low temperature could be considered to feed binary cycle power plants using organic fluids for electricity “production” or in cogeneration configuration. The improvement in the use of geothermal aquifers at low-medium enthalpy in small deep sites favours the reduction of drilling well costs, and in addition, it allows the exploitation of local resources in the energy districts. The heat exchanger evaporator enables the thermal heat exchange between the working fluid (which is commonly an organic fluid for an Organic Rankine Cycle) and the geothermal fluid (supplied by the aquifer). Thus, it has to be realised taking into account the thermodynamic proprieties and chemical composition of the geothermal field. The geothermal fluid is typically very aggressive, and it leads to the corrosion of steel traditionally used in the heat exchangers. This paper analyses the possibility of using plastic material in the constructions of the evaporator installed in an Organic Rankine Cycle plant in order to overcome the problems of corrosion and the increase of heat exchanger thermal resistance due to the fouling effect. A comparison among heat exchangers made of commonly used materials, such as carbon, steel, and titanium, with alternative polymeric materials has been carried out. This analysis has been built in a mathematical approach using the correlation referred to in the literature about heat transfer in single-phase and two-phase fluids in a tube and/or in the shell side. The outcomes provide the heat transfer area for the shell and tube heat exchanger with a fixed thermal power size. The results have demonstrated that the plastic evaporator shows an increase of 47.0% of the heat transfer area but an economic installation cost saving of 48.0% over the titanium evaporator.

Fuzzy Control of the 35t/h Chain Boiler with Regulable Rules

2012 ◽  
Vol 548 ◽  
pp. 425-428
Author(s):  
Feng Wang
Keyword(s):  
Fuzzy Control ◽  
Thermal Power ◽  
Steam Pressure ◽  
Steam Temperature ◽  
Level Control ◽  
Iron And Steel ◽  
Control Rule ◽  
On Line ◽  
A Chain ◽  
Fuzzy Control Algorithm

The 35t/h boiler used in the Thermal Power Plant of Tangshan Iron and Steel Co. Ltd. is a chain furnace. Its control system of the conmbustion process is a 2 input-2 output system whose inputs are the quantity of the fuel and desuperheater spray, outputs are the steam pressure and the steam temperature. Due to the nonlinearity, large lag, and coupling impact between the input and output parameters, fuzzy control was introduced. The fuzzy control rule has the adjustable factors and is described by the analytic relationships. The steam pressure is a 2-level control, including the original and final control. In the final control, the effect of the fuel quantity change on the steam temperature is taken into consideration. Thus the correction of the steam temperature for the fuel quantity is introduced. The control rule can be adjusted on-line owing to the regulable factors. For the reason, the control is closer to the actual production, which makes the production more smooth and reliable. Lastly, the modular structural design by means of PLC makes the realization of the fuzzy control algorithm more convenient.

scholarly journals Optimal tube diameter on heat exchanger shell and tube type with 15 mega watt thermal power using fluent 6.3

2018 ◽  
Vol 197 ◽  
pp. 02011
Author(s):  
Siti Nurhasanah ◽  
Muhammad Subekti ◽  
Moch. Nurul Subkhi ◽  
Bebeh Wahid Nuryadin
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Thermal Power ◽  
Mesh Size ◽  
Tube Type ◽  
Inner Diameter ◽  
Shell And Tube ◽  
The First Variation ◽  
Fluent 6.3

Heat exchanger shell and tube type is a set of tools that serve to move the heat from the side shell (hot fluid) to the tube (cold fluid). RSG-GAS Heat Exchangers is a heat exchanger shell and tube type 2-2. Since the age of Heat Exchanger operation long enough allow for new designs of heat transfer better. This is one reason the presence of micro modeling using Computational Fluid Dynamics (CFD), as one of them using the software FLUENT 6.3. Tube and shell modeled in GAMBIT with the variation ID (inner diameter) tube. As for the physical data such as flow rate, pressure, and temperature refers to the RSG-GAS Heat Exchangers. The first variation is the different mesh sizes for the tube that has the same diameter. Mesh size of 0.8 mm had the best result so do the meshing used as a benchmark for other models. Variations of 2D models use inner diameter from 20 mm until 26m. From CFD calculations using FLUENT 6.3 for 2D models, in the can that ID 20 mm, 23 mm and 26 mm can be used as models for 3D calculations. Of 3D calculations it can be concluded that the tube with an ID of 26 mm have the most optimal heat transfer is equal to 273,24669 K with a pressure drop of 450 Pa.

Effect of Heat Exchanger Orientations to Recover Heat From the Exhaust of a Diesel Generator Using Rankine Cycle (RC)

2015 ◽  
Author(s):  
S. Bari ◽  
Shekh N. Hossain
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Diesel Generator ◽  
Working Pressure ◽  
Exhaust Heat ◽  
Parallel Arrangement ◽  
Shell And Tube ◽  
Geometric Variables

The heat from the exhaust gas of diesel engines can be an important heat source to provide additional power and improve overall engine efficiency. Studies related to the applications of recoverable heat to produce additional power using separate Rankine cycle are scare. To recover heat from the exhaust of an engine, an efficient heat exchanger is necessary. For this type of application, the heat exchangers are needed to be designed in such a way that it can handle the heat load with reasonable size, weight and pressure drop. In this project, experiments were conducted to measure the exhaust heat available from a 40 kW diesel generator at different loads. Shell and tube heat exchangers were purchased and installed into the engine. The performance of the heat exchangers using water as the working fluid was then conducted. With the available data, computer simulation was carried out using CFD software CFX to improve the design of the heat exchangers. Geometric variables including length, number and diameter of tubes, and baffle design were all tested separately. Upon investigating how these parameters influenced the heat exchangers’ effectiveness, optimum design of shell and tube heat exchangers was proposed. The proposed heat exchangers were manufactured and experiment was conducted. Two heat exchangers were used to generate superheated steam. These two heat exchangers were arranged in two orientations namely, series and parallel. The proposed heat exchanger was able to produce 2.71 kW additional power using water as the working fluid at an optimum working pressure of 15 bar using parallel arrangement. It was found that parallel arrangement generated 10% more additional power than the series arrangement.

Waste Heat Recovery From the Exhaust of a Diesel Generator Using Shell and Tube Heat Exchanger

2013 ◽  
Author(s):  
Shekh N. Hossain ◽  
Saiful Bari
Keyword(s):  
Computer Simulation ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Diesel Generator ◽  
Tube Heat Exchanger ◽  
Hfc 134A ◽  
Shell And Tube

The heat from exhaust gas of diesel engines can be an important heat source to provide additional power and improve overall engine efficiency. Bottoming Rankine Cycle (RC) is one of the promising techniques to recover heat from the exhaust. One derivative of RC known as Organic Rankine Cycle (ORC) is also suitable for heat recovery for moderate and small size engines as the exhaust heat content and temperature of these engines are low. To recover heat from the exhaust of the engine, an efficient heat exchanger is necessary. In this current research, a shell and tube heat exchanger is optimized by computer simulation for two working fluids, water and HFC-134a. Two shell and tube heat exchangers were purchased and installed into a 40 kW diesel generator. The performance of the heat exchangers using water as the working fluid was then conducted. With the available data, computer simulation was carried out using CFD software ANSYS CFX14.0 to improve the design of the heat exchanger for both fluids. Geometric variables including length, number of tubes, and baffle design are all tested separately. Using the optimized heat exchangers simulation was conducted to estimate the possible additional power generation considering 80% isentropic turbine efficiency. The proposed heat exchanger was able to produce 11% and 9.4 % additional power using water and HFC-134a as the working fluid at maximum working pressure of 15 and 40 bar respectively. This additional power results into 12% and 11% improvement in brake-specific fuel consumption (bsfc) by using water and HFC-134a respectively. This indicates that besides water, organic fluids can also be a suitable option to recover heat from the exhaust of diesel engine.

scholarly journals Optimum Design of Shell and Tube Heat Exchangers using Modified Kinetic Gas Molecule Optimizer for the use of Low Temperature in Organic Rankine Cycles

2020 ◽  
Vol 9 (3) ◽  
pp. 1986-1993
Keyword(s):  
Heat Exchangers ◽  
Waste Heat ◽  
Research Work ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Low Grade ◽  
Medium Temperature ◽  
Learning Stage ◽  
Gas Molecule ◽  
Shell And Tube

Shell and Tube Heat Exchangers (STHEs) plays a crucial role in an effective design of Organic Rankine Cycle (ORC) power plants.The main aim of this research work is to design a cost-effective ORC in order to exploit low to medium temperature geothermal fluid or low grade industrial waste heat. In this research work, modified Kinetic Gas Molecule Optimization (KGMO) algorithm was developed forfinding the optimized parameter settings of the power plant. In modified KGMO algorithm, feedback learning stage was included for improving the fitness of individual worst particles. In addition, the proposed optimization algorithm was tested on two dissimilar fluids such asR245fa and R134a in order to show the effectiveness of proposed scheme. The experimental investigation showed that the proposed scheme effectively improved the heat exchanger performance as related to the existing schemes.The enhancement factor of proposed scheme was 2.8063 for R245fa fluid and 1.9346 for R134a fluid, which was better compared to the existing schemes; KGMO and Bell-Delaware method.

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