scholarly journals IMPROVING THE HEAT RECOVERY SYSTEM WITH STABILIZATION OF THE THERMAL PROCESSES OF ROTARY KILNS

2020 ◽  
pp. 114-121
Author(s):  
E.А. Geraskina ◽  
◽  
О.І. Khomenko ◽  
N.V. Danichenko ◽  
А.А. Khomenko ◽  
...  
Keyword(s):  
Rotary Kiln ◽  
Building Materials ◽  
Cooling System ◽  
Heat Removal ◽  
Side Surface ◽  
Utilization Efficiency ◽  
Controlled Cooling ◽  
Bypass Line ◽  
Entire Flow ◽  
Rotary Kilns

Abstract. The article is devoted to the problem of increasing the efficiency of using heating systems for industrial and municipal heat supply. The principles of rational cooling of furnaces and building materials are formulated, methods for stabilizing the thermal regime and conditions for the development of functional schemes for furnace units are determined. Rotary kilns under alternating of air temperature, wind speed, sunlight and precipitation lose from the side surface into the environment up to 30% of heat. The adverse effect of these factors negatively affects the thermal condition of the furnace unit with overheating in warm and overcooling in the cold periods of the year, and also reduces the lining stability and product quality. Characteristically, in order to maintain the necessary temperature at the inner surface of the furnace and extend the service life of the lining, the natural cooling of the side surface of the unit is assumed. This is an uncontrollable process with the above mentioned disadvantages. A radical solution to ensure the process requirements and improve utilization efficiency of fuel combustion energy is the organization of controlled cooling of the rotary kiln. One of the schemes providing the necessary heat removal from the furnace surface is a circuit with a recirculation channel. It is based on the reuse of the heating medium flow, the recirculation part of which increases with decreasing outdoor temperature. In the summer settlement mode, the system operates as a direct-flow system and the entire flow enters the consumer systems. In the winter billing period, air flows from the bypass line. Based on the above conditions, dependencies are established for finding the main parameters of the stabilizing cooling system of a rotary kiln, which is used for municipal heating.

scholarly journals Perfection of cooling systems of overhead tuyeres heads of 250-t BOFs

2019 ◽  
Vol 75 (3) ◽  
pp. 327-336
Author(s):  
S. P. Panteikov ◽  
L. M. Uchitel’ ◽  
V. V. Ivko ◽  
Yu. I. Kharchenko ◽  
Yu. P. Makhlai ◽  
...  
Keyword(s):  
Cooling System ◽  
Heat Removal ◽  
Internal Surface ◽  
Side Surface ◽  
Operating Characteristics ◽  
Blow Down ◽  
Cooling Systems ◽  
Nozzle Block ◽  
Heat Removal Efficiency ◽  
Positive Effect

Deterioration of tips cooling as a result of number of nuzzles increase in tuyere heads does not allow to use multinozzle (six and more) overhead tuyeres for increasing of steel melting technical and economical indices and operating characteristics of technological equipment. The main reason of it is as follows: deterioration ofcooling results in over-heating and burnt-outof tips material in the farthest nozzle zone following the overhead tuyeres breakage. To avoid the water stagnant areas in the farthestnozzle zones of the heads cooling route and therefore to increase the overheads oxygen tuyeres of 250-t BOF operation life, a new design of the six-nozzle tuyere head with asymmetric cooling of tips farthest zones elaborated, manufactures and tested. The perfection of the six-nozzle heads cooling system included asymmetric (relating the side surface of the nozzle block) installation behind every nozzle (in the water direction) a guidingblade of special design. It enabled to increase to a maximum degree the heat removal efficiency from the internal surface in the tip farthest zones and had a positive effect on the overhead tuyeres heads resistance. The workability of the proposed design of the six-nozzle tuyere head with asymmetric cooling of farthest zones was confirmed during test-industrial heats at 250-t BOFs of OJSC “Dneprovskysteel-works”. The heats were carried out with oxygen consumption of 800–1200 m 3/min and regime of partial afterburning ofexit gases. The water consumption for tuyeres cooling decrease from 320–340 m 3 /h, at that the  water temperature difference at the tuyere entry and exit varied in the range of 11–16 °C depending on blow-down duration. Application of the new design of the six-nozzle tuyere head with asymmetric farthest zones cooling enabled to increase the sixnozzle heads resistance by a factor 1.287 comparing with six-nozzle heads without farthest zones cooling and by a factor of 3.327 comparing with regular five-nozzle tuyere heads. The effect reached thanks to more rational cooler distribution and increase ofits velocity. The metal pick up of shafts of the six-nozzle tuyere head with asymmetric farthest zones cooling: while the five-nozzle tuyeres were taken off for salamander cutting off after 1–5 heats, the six-nozzle tuyeres were taken off for the salamander cutting off after 79–81 heats. It indicated a higher efficiency of heat running blow-down and slag regimes with application of proposed design of the six-nozzle tuyere head with asymmetric farthest zones cooling.

Use of Logistic Approach in Optimizing the Rotary Kiln Run

2013 ◽  
Vol 483 ◽  
pp. 518-523
Author(s):  
Julius Lisuch ◽  
Jaroslav Gonos
Keyword(s):  
Rotary Kiln ◽  
Positive Impact ◽  
Raw Materials ◽  
Mining Industry ◽  
Innovation Process ◽  
Energy Output ◽  
Controlled Cooling ◽  
Treatment Area ◽  
Burning Process ◽  
Rotary Kilns

The strategic object of the innovation process in the raw materials extracting and treatment area is a sustainable development in all its components, particularly in the material, economic, environmental and energy. The paper presents a concrete contribution to the achievement of this goal by applying the principles of logistics in technical and technological optimization of rotary kilns operation with a positive impact in the energetic field especially. Rotary kilns are a long-term core technology of heat aggregates within the mining industry. Today there is a characteristic potential optimization exhaustion of classical optimization approaches and persistent lack of a major operation - high specific fuel consumption. The article presented a solution focused at eliminating the furnace jacket heat loss, which represents around 30% of the total energy output of the burning process and the largest energetic loss. The basis of the presented innovative solutions - the controlled cooling of the furnace jacket is the perfect knowledge of thermodynamics, hydro-mechanical and rheological flows in the process of burning in a rotary kiln and logistics optimization approaches application. The developed controlled furnace cooling jacket system delivers the performance and quality of the burning, reducing an overall energy consumption for the burning process in a rotary kiln by reducing rotary kiln shell losses and by use of the outgoing heat to the surroundings for the combustion air heating.

scholarly journals Performance Analysis of Hybrid Desiccant Cooling System with Enhanced Dehumidification Capability Using TRNSYS

2021 ◽  
Vol 11 (7) ◽  
pp. 3236
Author(s):  
Ji Hyeok Kim ◽  
Joon Ahn
Keyword(s):  
Thermal Comfort ◽  
Cooling System ◽  
Operation Mode ◽  
Heat Removal ◽  
Simulation Models ◽  
Coefficient Of Performance ◽  
Dimensional Structure ◽  
Dominant Factor ◽  
Exhaust Heat ◽  
Chp System

In a field test of a hybrid desiccant cooling system (HDCS) linked to a gas engine cogeneration system (the latter system is hereafter referred to as the combined heat and power (CHP) system), in the cooling operation mode, the exhaust heat remained and the latent heat removal was insufficient. In this study, the performance of an HDCS was simulated at a humidity ratio of 10 g/kg in conditioned spaces and for an increasing dehumidification capacity of the desiccant rotor. Simulation models of the HDCS linked to the CHP system were based on a transient system simulation tool (TRNSYS). Furthermore, TRNBuild (the TRNSYS Building Model) was used to simulate the three-dimensional structure of cooling spaces and solar lighting conditions. According to the simulation results, when the desiccant capacity increased, the thermal comfort conditions in all three conditioned spaces were sufficiently good. The higher the ambient temperature, the higher the evaporative cooling performance was. The variation in the regeneration heat with the outdoor conditions was the most dominant factor that determined the coefficient of performance (COP). Therefore, the COP was higher under high temperature and dry conditions, resulting in less regeneration heat being required. According to the prediction results, when the dehumidification capacity is sufficiently increased for using more exhaust heat, the overall efficiency of the CHP can be increased while ensuring suitable thermal comfort conditions in the cooling space.

Validation of Film Evaporation Model in GASFLOW-MPI

2018 ◽  
Author(s):  
Li Yabing ◽  
Zhang Han ◽  
Xiao Jianjun
Keyword(s):  
Experimental Data ◽  
Wall Temperature ◽  
Cooling System ◽  
Numerical Study ◽  
Thermal Power ◽  
Heat Removal ◽  
Air Velocity ◽  
Evaporation Model ◽  
Film Evaporation ◽  
Test Region

A dynamic film model is developed in the parallel CFD code GASFLOW-MPI for passive containment cooling system (PCCS) utilized in nuclear power plant like AP1000 and CAP1400. GASFLOW-MPI is a widely validated parallel CDF code and has been applied to containment thermal hydraulics safety analysis for different types of reactors. The essential issue for PCCS is the heat removal capability. Research shows that film evaporation contributes most to the heat removal capability for PCCS. In this study, the film evaporation model is validated with separate effect test conducted on the EFFE facility by Pisa University. The test region is a rectangle gap with 0.1m width, 2m length, and 0.6m depth. The water film flowing from the top of the gap is heated by a heating plate with constant temperature and cooled by countercurrent air flow at the same time. The test region model is built and analyzed, through which the total thermal power and evaporation rate are obtained to compare with experimental data. Numerical result shows good agreement with the experimental data. Besides, the influence of air velocity, wall temperature and gap widths are discussed in our study. Result shows that, the film evaporation has a positive correlation with air velocity, wall temperature and gap width. This study can be fundamental for our further numerical study on PCCS.

scholarly journals EFFECTIVE USE OF ROTARY FURNACE SHELL HEAT

2014 ◽  
Vol 54 (6) ◽  
pp. 414-419
Author(s):  
Julius Lisuch ◽  
Dusan Dorcak ◽  
Jan Spisak
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Raw Materials ◽  
Significant Proportion ◽  
Rotary Furnace ◽  
Cost Effective ◽  
Total Energy Expenditure ◽  
Heat Losses ◽  
Controlled Cooling ◽  
Effective Use

<pre><pre>Significant proportion of the total energy expenditure for the heat treatment of raw materials are heat losses through the shell of rotary furnace. Currently, the waste heat is not used in any way and escapes into the environment. Controlled cooling system for rotary furnace shell (<span>CCSRF</span>) is a new solution integrated into the technological process aimed at reducing the heat loss of the furnace shell. Based on simulations and experiments carried out was demonstrated a significant effect of controlled cooling shell to the rotary furnace work. The proposed solution is cost-effective and operationally undemanding.</pre></pre>

Experimental Analysis of Different Coolants Used in Plasma Cutting Operation for the Improved Electrode Life

2015 ◽  
Vol 719-720 ◽  
pp. 46-49 ◽  
Author(s):  
Ginka Ranga Janardhana ◽  
Mani Senthil Kumar ◽  
B. Dhanasekar
Keyword(s):  
Temperature Rise ◽  
Metal Cutting ◽  
Cooling System ◽  
Heat Removal ◽  
Plasma Cutting ◽  
Life Test ◽  
Flow Rates ◽  
Optimal Flow ◽  
Cutting Operation ◽  
The Impact

The plasma cutting technology has been emerged as a developing technology which finds tremendous potential in fabrication and metal cutting industries. Thus for the cutting operation, the electrode inside the plasma torch plays a vital role for the plasma arc generation. The temperature of the arc is very high and at the electrode is around 3500°C. The cutting torch requires proper cooling system in order to prevent the electrode from quick wear due to the existence of high thermal gradient. The presented work aimed to study the impact of three coolants propylene glycol, ethylene glycol and de-ionized water flow over the electrode life. The experimental setups were arranged to study the heat transfer capabilities of the three coolants for different flow values and aimed to achieve the optimal flow rates for the efficient heat removal. The electrode life test trials were conducted to measure the electrode life for the flow values of three coolants in the temperature rise test. The optimal flow rates arrived from temperature rise test and the electrode life measured from life test are compared for the three coolant cases considered.

scholarly journals Design of the VISTA-ITL Test Facility for an Integral Type Reactor of SMART and a Post-Test Simulation of a SBLOCA Test

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Hyun-Sik Park ◽  
Byung-Yeon Min ◽  
Youn-Gyu Jung ◽  
Yong-Cheol Shin ◽  
Yung-Joo Ko ◽  
...  
Keyword(s):  
System Analysis ◽  
Cooling System ◽  
Heat Removal ◽  
Test Facility ◽  
Integral Type ◽  
Type Reactor ◽  
Integral Effect ◽  
Post Test ◽  
Design Characteristics ◽  
And Performance

To validate the performance and safety of an integral type reactor of SMART, a thermal-hydraulic integral effect test facility, VISTA-ITL, is introduced with a discussion of its scientific design characteristics. The VISTA-ITL was used extensively to assess the safety and performance of the SMART design, especially for its passive safety system such as a passive residual heat removal system, and to validate various thermal-hydraulic analysis codes. The VISTA-ITL program includes several tests on the SBLOCA, CLOF, and PRHRS performances to support a verification of the SMART design and contribute to the SMART design licensing by providing proper test data for validating the system analysis codes. A typical scenario of SBLOCA was analyzed using the MARS-KS code to assess the thermal-hydraulic similarity between the SMART design and the VISTA-ITL facility, and a posttest simulation on a SBLOCA test for the shutdown cooling system line break has been performed with the MARS-KS code to assess its simulation capability for the SBLOCA scenario of the SMART design. The SBLOCA scenario in the SMART design was well reproduced using the VISTA-ITL facility, and the measured thermal-hydraulic data were properly simulated with the MARS-KS code.

Ex-Vessel Loss of Coolant Accident Analysis of ITER Divertor Cooling System Using Modified RELAP/SCADAPSIM/Mod 4.0

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
S. P. Saraswat ◽  
P. Munshi ◽  
A. Khanna ◽  
C. Allison
Keyword(s):  
Heat Flux ◽  
Cooling System ◽  
Heat Removal ◽  
Hydraulic Modeling ◽  
Carbon Fiber Composites ◽  
High Heat Flux ◽  
Vacuum Vessel ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant ◽  
Accident Scenarios

The initial design of ITER incorporated the use of carbon fiber composites in high heat flux regions and tungsten was used for low heat flux regions. The current design includes tungsten for both these regions. The present work includes thermal hydraulic modeling and analysis of ex-vessel loss of coolant accident (LOCA) for the divertor (DIV) cooling system. The purpose of this study is to show that the new concept of full tungsten divertor is able to withstand in the accident scenarios. The code used in this study is RELAP/SCADAPSIM/MOD 4.0. A parametric study is also carried out with different in-vessel break sizes and ex-vessel break locations. The analysis discusses a number of safety concerns that may result from the accident scenarios. These concerns include vacuum vessel (VV) pressurization, divertor temperature profile, passive decay heat removal capability of structure, and pressurization of tokamak cooling water system. The results show that the pressures and temperatures are kept below design limits prescribed by ITER organization.

scholarly journals Analysis of Wetting Characteristics on Microstructured Hydrophobic Surfaces for the Passive Containment Cooling System

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Zhao ◽  
Xiang Zhang ◽  
Chunlai Tian ◽  
Zhan Gao
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Performance ◽  
Cooling System ◽  
Heat Removal ◽  
Interface State ◽  
Transfer Performance ◽  
Hydrophobic Property ◽  
High Mechanical Strength ◽  
Feasible Solutions ◽  
Baxter Model

As the heat transfer surface in the passive containment cooling system, the anticorrosion coating (AC) of steel containment vessel (CV) must meet the requirements on heat transfer performance. One of the wall surface ACs with simple structure, high mechanical strength, and well hydrophobic characteristics, which is conductive to form dropwise condensation, is significant for the heat removal of the CV. In this paper, the grooved structures on silicon wafers by lithographic methods are systematically prepared to investigate the effects of microstructures on the hydrophobic property of the surfaces. The results show that the hydrophobicity is dramatically improved in comparison with the conventional Wenzel and Cassie-Baxter model. In addition, the experimental results are successfully explained by the interface state effect. As a consequence, it is indicated that favorable hydrophobicity can be obtained even if the surface is with lower roughness and without any chemical modifications, which provides feasible solutions for improving the heat transfer performance of CV.

scholarly journals Impact of Elevated Temperatures on Strength Properties and Microstructure of Calcium Sulfoaluminate Paste

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6751
Author(s):  
Konrad A. Sodol ◽  
Łukasz Kaczmarek ◽  
Jacek Szer ◽  
Sebastian Miszczak ◽  
Mariusz Stegliński
Keyword(s):  
Compressive Strength ◽  
Building Materials ◽  
Elevated Temperatures ◽  
Cooling System ◽  
Base Material ◽  
Visual Assessment ◽  
Strength Properties ◽  
Strength Parameters ◽  
Calcium Sulfoaluminate ◽  
Wide Range

This article is motivated by civil fire safety. Fire-prevention engineering demands a wide range of information about building materials including alternative cements, for instance CSA-cement. Because of exposure of the cement-base material to a high temperature, its strength properties deteriorate due to dehydration connected with phase and microstructure changes. Previous research indicated that the main endothermic reaction of CSA-based composite, dehydration of ettringite, might be used as a cooling system for a metal structure during fire-load. This article examines visual assessment, microstructure, density, as well as flexural and compressive strength parameters of CSA-based composite after isothermal heating at temperatures from 23 °C to 800 °C. The results of SEM/EDS investigations showed that the calcium sulfoaluminate paste may start partially re-sintering above 600 °C. Mechanical tests revealed significant reduction of strength parameters but residual compressive strength was maintained in the whole temperature range e.g., 8 MPa at 800 °C. Additionally, visual assessment of the specimens indicated that it might be possible to predict the material temperature heating based on the specific surface color. These findings add to the evidence of general knowledge about CSA hydrates.

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