Systems of utilization of secondary steam of apparatus for beer wort

2020 ◽  
Vol 26 (4) ◽  
pp. 98-112
Author(s):  
A. Sokolenko ◽  
О. Shevchenko ◽  
V. Kostyuk ◽  
S. Litvynchuk
Keyword(s):  
Secondary Steam

Assessment of RELAP/SCDAPSIM for Turbine Trip Transient in NuScale-SMR

2018 ◽  
Author(s):  
Katarzyna Skolik ◽  
Anuj Trivedi ◽  
Marina Perez-Ferragut ◽  
Chris Allison
Keyword(s):  
Natural Circulation ◽  
System Modeling ◽  
Thermal Power ◽  
Reactor Core ◽  
Operating Conditions ◽  
Severe Accident ◽  
Circulation System ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Secondary Steam

The NuScale Small Modular Reactor (SMR) is an integrated Pressurized Water Reactor (iPWR) with the coolant flow based on the natural circulation. The reactor core consists of 37 fuel assemblies similar to those used in typical PWRs, but only half of their length to generate 160MW thermal power (50 MWe). Current study involves the development of a NuScale-SMR model based on its Design Certification Application (DCA) data (from NRC) using RELAP/SCDAPSIM. The turbine trip transient (TTT) was simulated and analysed. The objective was to assess this version of the code for natural circulation system modeling capabilities and also to verify the input model against the publicly available TTT results obtained using NRELAP5. This successful benchmark confirms the reliability of the thermal hydraulic model and allows authors to use it for further safety and severe accident analyses. The reactor core channels, pressurizer, riser and downcomer pipes as well as the secondary steam generator tubes and the containment were modeled with RELAP5 components. SCDAP core and control components were used for the fuel elements in the core. The final input deck achieved the steady state with the operating conditions comparable to those reported in the DCA. RELAP/SCDAPSIM predictions are found to be satisfactory and comparable to the reference study. It confirms the code code capabilities for natural circulation system transients.

Simulation of Hydrogen Production From Biomass Pyrolysis Gas by Secondary Steam Reforming

2008 ◽  
Author(s):  
Leteng Lin ◽  
Li Sun ◽  
Xiaodong Zhang ◽  
Xiaolu Yi ◽  
Min Xu
Keyword(s):  
Fuel Cells ◽  
Hydrogen Production ◽  
Gas Turbine ◽  
Steam Reforming ◽  
Water Gas Shift ◽  
Hydrogen Yield ◽  
Biomass Pyrolysis ◽  
Pyrolysis Gas ◽  
Secondary Steam ◽  
Water Gas

Hydrogen is currently being widely regarded as a futural energy carrier to reduce carbon emissions and other NOx and SOx pollutants. Many researchers have proved that hydrogen can be efficiently used in solid oxide fuel cells -gas turbine system (SOFC-GT) and molten carbonate fuel cells-gas turbine system (MCFC-GT). Hydrogen production from biomass resources offers the advantage of providing a renewable energy carrier for extensive reduction of the CO2 emission. A secondary steam reforming process which consists of steam reforming of methane and water gas shift was proposed to further convert CH4, CO and other hydrocarbons in biomass pyrolysis gas for promoting hydrogen yield. According to respective reaction mechanism, simulating calculations were carried out in two reforming processes separately. With the favor of PRO/II, the effects of reaction temperature and steam to carbon ratio on hydrogen yield were discussed in details in the steam reforming of methane. A reasonable calculation method was established for simulating the water gas shift process in which the effects of temperature and steam to CO ratio was investigated. The simulation made good results in optimizing reaction conditions for two reformers and predicting the volume rate of all gas components. It is proved by simulation that hydrogen-rich gas with >68 mol% H2 could be produced, and the hydrogen yield could reach 48.18 mol H2/(Kg Biomass) and 45.85 mol/(Kg Biomass) respectively when using corn straw and rice husk as feedstock. The experiment data from a related reference was adopted to prove the reasonability of the simulation results which could show the feasibility of secondary steam reforming process, as well as provide good references for practical process operation.

Secondary steam models of a combined cycle power plant simulator

2011 ◽  
Vol 3 (2) ◽  
pp. 145
Author(s):  
Edgardo J. Roldan Villasana ◽  
Ma. de Jesus Cardoso Goroztieta ◽  
Adriana Verduzco Bravo ◽  
Jorge J. Zorrilla Arena
Keyword(s):  
Power Plant ◽  
Combined Cycle ◽  
Combined Cycle Power Plant ◽  
Secondary Steam

Comparison of Nuclear Power Plants With Closed-Cycle Helium Turbine and With Steam Turbine Cycle for Combined Power and Steam Generation

1973 ◽  
Vol 95 (1) ◽  
pp. 11-18 ◽  
Author(s):  
K. Bammert ◽  
R. Buende
Keyword(s):  
Steam Turbine ◽  
Nuclear Power ◽  
Power Plants ◽  
Closed Cycle ◽  
Steam Generation ◽  
Single Cycle ◽  
Cycle System ◽  
System A ◽  
Secondary Steam

The heat of a helium-cooled reactor can be used for combined power and steam generation either in a closed-cycle helium turbine system, the so-called single-cycle system, or in a two-cycle system which consists of a helium cycle and a secondary steam turbine cycle. The optimum data for the two systems are determined within the same range of general parameters—electric power output and quantity and quality of the steam produced—as functions of the special parameters of each particular cycle system. A method of comparing different power plant systems is shown. With this method it is possible to determine those ranges in which the efficiencies achieved with one system are higher than those obtained with the other. It is described in which way the dividing line between such ranges depends on the special parameters of the cycles. The comparison shows that the single-cycle system offers advantages.

scholarly journals Thermodynamic Analysis and Optimization of Secondary Overheating Parameters in Turbo-Expander Plants on Low Boiling Working Fluids

2021 ◽  
Vol 64 (2) ◽  
pp. 164-177
Author(s):  
A. V. Ovsyannik ◽  
V. P. Kliuchinski
Keyword(s):  
Heat Exchanger ◽  
Thermodynamic Analysis ◽  
Critical Pressure ◽  
Steam Superheater ◽  
Working Fluid ◽  
Exergetic Efficiency ◽  
Working Fluids ◽  
Secondary Steam ◽  
Turbo Expander ◽  
Expander Cycle

The paper presents a thermodynamic analysis of secondary overheating in turbo-expander plants on low-boiling working fluids. The possibility of optimizing the parameters of the working fluid in a secondary stem superheater has been studied. The research was carried out for two typical turbo-expander cycles: with a heat exchanger at the outlet of the turbo-expander, intended for cooling an overheated low-boiling working fluid, and without a heat exchanger. Cycles in T–s coordinates were constructed for the studied schemes. The influence of pressure and temperature in the intermediate superheater on the exergetic efficiency of the turbo-expander unit was studied. Thus, the dependences of the exergetic efficiency and losses on the elements of the turbo-expander cycle are obtained when the temperature of the working fluid changes and pressure of the working fluid not changes in the intermediate superheater, and when the pressure changes and the temperature does not change. As a low-boiling working fluid, the ozone-safe freon R236EA is considered, which has a “dry” saturation line characteristic, zero ozone layer destruction potential, and a global warming potential equal to 1370. It has been determined that increasing the parameters of the low-boiling working fluid in front of the low-pressure turbo expander (regardless of the scheme of the turbo expander cycle) does not always cause an increase in the exergetic efficiency. Thus, overheating of the working fluid at a pressure exceeding the critical pressure causes a positive exergetic effect, but for each temperature there is an optimal pressure at which the efficiency will be maximum. At a pressure below the critical pressure, overheating leads to a decrease in the exergetic efficiency, and the maximum exergetic effect is achieved in the absence of a secondary steam superheater. All other things being equal, a turbo-expander cycle with a heat exchanger is more efficient than without it over the entire temperature range and pressure of the low-boiling working fluid under study.

scholarly journals Technological breakthrough of the agrarian-and-food innovations in dairy case for example of universal agricultural raw materials. Reverse osmosis

2021 ◽  
Vol 14 ◽  
pp. 7-20
Author(s):  
A.G. Khramtsov ◽  
Keyword(s):  
Reverse Osmosis ◽  
Raw Materials ◽  
Production Cycle ◽  
Industrial Complex ◽  
Recycled Water ◽  
Controlled Processing ◽  
Technology Process ◽  
Secondary Steam ◽  
Osmotic Treatment ◽  
Membrane Treatment

Aim. Consideration of the membrane technology process – reverse osmosis – by directed and controlled processing of whey and its filtrates through special semipermeable partitions (filter membranes) with a pore size from 0.1 to 1.0 nm, carried out at a pressure of 3.0 - 10.0 MPa with the release of particles (cutting off) with a molecular weight of 100 Daltons. Reverse osmosis allows you to concentrate all the compounds of whey and filtrates, separating almost distilled water (condensate). Discussion. In the molecular sieve separation system, reverse osmosis logically continues the membrane treatment of filtrates (permeates) of native, as well as separated whey and their microfiltrates, ultrafiltrates, nanofiltrates and diafiltrates. In principle, the reverse osmosis process should be implemented to pre-concentrate the whey, which will eliminate its loss (draining) and expand the range of use. OO is promising for processing salted whey with the removal of unwanted sodium chloride, as well as for cleaning the condensate of evaporation plants from the components of dairy raw materials that come with foam and secondary steam. Conclusion. In general, for the dairy industry of the food industry of the agro-industrial complex, reverse osmotic treatment is necessary for the implementation of a closed production cycle with a recycled water supply.

Analyses of the Failed Impulsion Lines of NPP Dukovany Steam Generator

2009 ◽  
Author(s):  
M. Postler ◽  
J. Burda ◽  
P. Tkadlcˇi´k
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Steam Generator ◽  
Confined Space ◽  
Steam Generators ◽  
Root Cause ◽  
Secondary Steam ◽  
Control Procedures ◽  
And Control ◽  
Tube Segment

Over the years the cracks have been detected on the impulsion lines of all steam generators of the NPP Dukovany. The tubing is made from the austenitic stainless steel. These lines are designed for purposes of measurement and also containment of possible leaks, e.g. between the primary and secondary steam generator seals. Their integrity is periodically tested during each outage and if the leak is detected the tube segment must be cut out and the new one is welded in place. Most of the time the tubes are “dry”, i.e. no medium is flowing inside. Due to confined space the movement of persons around the steam generator is difficult and often the relatively subtle impulsion lines have been subjected to stresses leading to their bending. This deformation has then led to evolution of the failure. To address the issue the original manufacturing, test and control procedures for the impulsion tubing have been studied. Several cracked tubes have been analyzed thoroughly to find the root cause and offer possible remedies.

scholarly journals INVESTIGATION OF EVAPORATION AND CONDENSATION PROCESS OF INDUCED FLOW USING STEAM EJECTOR

2021 ◽  
Vol 16 (2) ◽  
Author(s):  
Shahad Jamal
Keyword(s):  
Mathematical Model ◽  
Mass Flow ◽  
Nozzle Outlet ◽  
Entrainment Ratio ◽  
Flow Rates ◽  
Steam Ejector ◽  
Secondary Steam ◽  
Induced Flow ◽  
Ejector Nozzle ◽  
The Mathematical Model

The research aims to understand the design parameters of steam ejector nozzle on the performance of flash evaporation induced by the effect of a steam jet passing through it. The research concentrates on studying the effect of ejector nozzle outlet diameter on induced flow from preheated water in a specified evaporator using a subsonic ejector. The thermal energy extracted from the condensed steam mixture in the condenser is used to heat the water in the evaporator. The experimental tests investigate the effect of nozzle geometry on the induced evaporation process by changing nozzle outlet diameter while keeping the pressure of evaporator, condenser and primary steam constant. The experimental results proved that both primary and secondary steam mass flow rates increase versus nozzle outlet diameter, while the entrainment ratio of secondary to primary steam flow rates decreases due to the restricted increase of the secondary steam mass flow rate. The mathematical model prepared to simulate the behaviour of the subsonic ejector is validated using the comparison between experimental and theoretical results. The mathematical model showed that maximum entrainment of 0.57 is obtained at a primary steam pressure of 2 bars when the nozzle outlet diameter is fixed at 1.5 mm, while minimum entrainment ratio of 0.17 is estimated at 1.5 bar pressure related to primary steam when the nozzle outlet diameter is fixed at 2.5mm. The authors recommend defining nozzle geometrical parameters according to the operating conditions of the experimental test rig to enhance ejector efficiency.

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