Practical Considerations When Conducting a Transient Analysis of a Heat Exchanger Tube Rupture

2012 ◽  
Author(s):  
David R. Thornton ◽  
Robert A. Sadowski ◽  
Philip A. Henry
Keyword(s):  
High Pressure ◽  
Heat Exchanger ◽  
Transient Analysis ◽  
Low Pressure ◽  
Lower Pressure ◽  
Pressure Side ◽  
Analysis Methodology ◽  
Large Pressure ◽  
Process Plants ◽  
Shell And Tube

As part of operations, petrochemical and process plants sometimes require the exchange of heat between a high pressure fluid and a lower pressure fluid in shell-and-tube heat exchangers. In most cases, the high pressure fluid exists on the tubeside and the lower pressure is on the shellside. While rare, it is possible for a tube inside the exchanger shell to rupture suddenly, releasing the high pressure fluid into the shellside. If the pressure of the high pressure fluid exceeds the design pressure of the low pressure shell or its attached piping, it might be possible for the resulting pressure in the low pressure side to exceed permitted values. In such cases, API 521 provides guidance on assuring that sufficient pressure relief is available to limit the pressures on the heat exchanger(s)’ low pressure side. An overpressure analysis per API 521 can include both steady-state and transient analysis methods for determining that the pressures remain within acceptable levels. In situations where a large pressure differential exists between the high and low pressure sides of the exchanger, the transient, hydraulic analysis of the tube rupture event can be used as a tool to help mitigate over pressure. After briefly discussing the analysis methodology, this paper discusses some of the practical considerations and decisions that normally go into conducting the analysis.

Pressure Variation in Low Pressure Side of Shell and Tube Heat Exchanger After Tube Rupture

2014 ◽  
Author(s):  
Ganesh S. Katke ◽  
M. Venkatesh ◽  
N. P. Gulhane
Keyword(s):  
High Pressure ◽  
Heat Exchanger ◽  
Low Pressure ◽  
Pressure Variation ◽  
Operating Pressure ◽  
Pressure Side ◽  
Tube Heat Exchanger ◽  
Analytical Algorithm ◽  
Shell And Tube ◽  
Design Pressure

This paper presents an analytical algorithm to determine the pressure variation on the Low Pressure side of a Shell and Tube Heat Exchanger (STHE) after a tube rupture and its validation using CFD simulation. STHEs are often used for exchanging heat between high-pressure (HP) and low-pressure (LP) fluids in the chemical process industry. In case tube rupture occurs in a STHE having a large pressure difference between HP and LP side, there is a risk of release of significant quantity of fluid from the HP side to the LP side. The consequent pressure build-up can lead to the failure of LP side pressure envelope. Generally, design pressure of the LP side is about 10–20% higher than the operating pressure of the LP side fluid, but well below the operating pressure on the HP side. There is no well-established methodology to design the LP side to withstand sudden release of high pressure fluid following a tube rupture. Three dimensional analyses were carried out using Computational Fluid Dynamics to study the pressure variation in LP side (shell side) of a Gas Cooler and to validate the results obtained from the analytical algorithm. It has been observed that the pressure on the LP side exceeds the design pressure instantaneously due to generation of a pressure pulse after tube rupture. This may lead to damage of LP envelope (shell) and internal structure of STHE.

scholarly journals Assessment of Severe Accident Management for Small IPWR under an ESBO Scenario

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Hao Yu ◽  
Minjun Peng
Keyword(s):  
High Pressure ◽  
Low Pressure ◽  
Lower Pressure ◽  
Severe Accident ◽  
Maximum Temperature ◽  
Pressurized Water ◽  
The Core ◽  
Severe Accidents ◽  
Accident Management ◽  
Degradation Studies

Interest in evaluation of severe accidents induced by extended station blackout (ESBO) has significantly increased after Fukushima. In this paper, the severe accident process under the high and low pressure induced by an ESBO for a small integrated pressurized water reactor (IPWR)-IP200 is simulated with the SCDAP/RELAP5 code. For both types of selected scenarios, the IP200 thermal hydraulic behavior and core meltdown are analyzed without operator actions. Core degradation studies firstly focus on the changes in the core water level and temperature. Then, the inhibition of natural circulation in the reactor pressure vessel (RPV) on core temperature rise is studied. In addition, the phenomena of core oxidation and hydrogen generation and the reaction mechanism of zirconium with the water and steam during core degradation are analyzed. The temperature distribution and time point of the core melting process are obtained. And the IP200 severe accident management guideline (SAMG) entry condition is determined. Finally, it is compared with other core degradation studies of large distributed reactors to discuss the influence of the inherent design characteristics of IP200. Furthermore, through the comparison of four sets of scenarios, the effects of the passive safety system (PSS) on the mitigation of severe accidents are evaluated. Detailed results show that, for the quantitative conclusions, the low coolant storage of IP200 makes the core degradation very fast. The duration from core oxidation to corium relocation in the lower-pressure scenario is 53% faster than that of in the high-pressure scenario. The maximum temperature of liquid corium in the lower-pressure scenario is 134 K higher than that of the high-pressure scenario. Besides, the core forms a molten pool 2.8 h earlier in the lower-pressure scenario. The hydrogen generated in the high-pressure scenario is higher when compared to the low-pressure scenario due to the slower degradation of the core. After the reactor reaches the SAMG entry conditions, the PSS input can effectively alleviate the accident and prevent the core from being damaged and melted. There is more time to alleviate the accident. This study is aimed at providing a reference to improve the existing IPWR SAMGs.

Drilling Riser Design and Analysis for Deepwater Applications

2013 ◽  
Author(s):  
Yongming Cheng ◽  
Tao Qi
Keyword(s):  
High Pressure ◽  
Production Systems ◽  
Dynamic Performance ◽  
Design Procedure ◽  
Dynamic Strength ◽  
Low Pressure ◽  
Strength Analysis ◽  
Global Dynamic ◽  
Analysis Methodology ◽  
Riser Design

A riser is a fluid conduit from subsea equipment to surface floating production systems such as spars, TLPs, and semi-submersibles. It is a key component in a drilling and producing system. Drilling risers include the applications in marine drilling (low pressure) and tie-back drilling (high pressure). This paper discusses drilling riser design and analysis for a deepwater application. This paper first discusses the configuration of marine drilling and tie-back drilling risers. It then presents the drilling riser design procedure and analysis methodology. The riser design and analysis cover the riser tensioner setting, marine operation window, strength and fatigue, etc. A marine drilling riser example is used in the paper to demonstrate the design and analysis for a deepwater application. This paper shows the dynamic strength analysis results for the riser. It then identifies governing locations for the riser design. A tie-back drilling riser example is also provided to illustrate its global dynamic performance. This paper finally discusses the design and analysis challenges of a drilling riser for a deepwater application.

Reducing Energy Consumption for Seawater Desalination through the Application of Reflux-Recycle Concepts from Oil Refining

2013 ◽  
Vol 295-298 ◽  
pp. 1456-1462 ◽  
Author(s):  
K. E. Ting ◽  
H.T. Ng ◽  
H.C. Li
Keyword(s):  
High Pressure ◽  
Energy Consumption ◽  
Specific Energy Consumption ◽  
Low Pressure ◽  
Hybrid Membrane ◽  
Oil Refining ◽  
Pressure Side ◽  
Seawater Desalination ◽  
Feed Concentration ◽  
Membrane Processes

The application of the concepts in oil and gas distillation to membrane desalination process to lower the energy cost for seawater desalination was studied in this paper. Drawing on the close analogy between multistage RO and conventional distillation separation processes, a hybrid membrane processes employing reflux and recycle concepts was developed. Reflux in membrane processes involves taking a portion of the effluent stream on the high pressure side and sending it to the low pressure side of the membrane, while recycle involves taking a portion of the permeate stream on the low pressure side and sending it to the high pressure side of the membrane. A predictive model was developed to study the effect of reflux and recycle on the specific energy consumption (SEC) and permeate quality when compared to conventional systems. In this study, the water permeability coefficients of membranes and brine recycle ratios were investigated. The results show that the SEC for a hybrid membrane processes comprising of RO and NF membrane was lower than conventional methods with the same recovery and feed concentration, suggesting that it is feasible to apply reflux and recycle concepts of distillation on desalination. Through the careful selection of RO membranes and NF membranes, benefits of reflux and recycle can be enjoyed for seawater desalination.

scholarly journals On the Optimal Tube Spacing for Shell-and-Tube Gas Turbine Recuperators

1979 ◽  
Author(s):  
W. Hilary Lee
Keyword(s):  
High Pressure ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Minimum Weight ◽  
Diameter Ratio ◽  
Minimum Volume ◽  
Tube Heat Exchanger ◽  
Shell And Tube

The effect of high pressure inside and outside of tubes and of pressure ratios on tube spacings associated with minimum volume and minimum weight of shell-and-tube gas turbine recuperators, is examined. For this purpose, a method was developed for analyzing volume and weight of shell-and-tube heat exchanger surfaces. The influence of TEMA recommended minimum spacing-to-diameter ratio on the result is discussed. Implications of the above findings on gas turbine recuperator design is sketched.

Practical Experience With a Mobile Methanol Synthesis Device

2014 ◽  
Author(s):  
Eric R. Morgan ◽  
Tom Acker
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Methanol Synthesis ◽  
Low Pressure ◽  
Practical Experience ◽  
Gaseous Hydrogen ◽  
Water Mixture ◽  
Pressure Side ◽  
Northern Arizona ◽  
Northern Arizona University

Northern Arizona University has developed a methanol synthesis unit that directly converts carbon dioxide and hydrogen into methanol and water. The methanol synthesis unit consists of: a high pressure side that includes a compressor, a reactor, and a throttling valve; and a low pressure side that includes a knockout drum, and a mixer where fresh gas enters the system. Methanol and water are produced at high pressure in the reactor and then exit the system under low pressure and temperature in the knockout drum. The remaining, unreacted recycle gas that leaves the knockout drum is mixed with fresh synthesis gas before being sent back through the synthesis loop. The unit operates entirely on electricity and includes a high-pressure electrolyzer to obtain gaseous hydrogen and oxygen directly from purified water. Thus, the sole inputs to the trailer are water, carbon dioxide and electricity, while the sole outputs are methanol, oxygen, and water. A distillation unit separates the methanol and water mixture on site so that the synthesized water can be reused in the electrolyzer. Here, we describe and characterize the operation of the methanol synthesis unit and offer some possible design improvements for future iterations of the device, based on experience.

Design and Test Plan of the Supercritical CO2 Compressor Test Loop

2008 ◽  
Author(s):  
Takao Ishizuka ◽  
Yasushi Muto ◽  
Masanori Aritomi
Keyword(s):  
High Pressure ◽  
Critical Point ◽  
Thermal Efficiency ◽  
Supercritical Co2 ◽  
Thermal Power ◽  
Low Pressure ◽  
Fiscal Year ◽  
Pressure Side ◽  
Test Loop ◽  
Pressure Compressor

Supercritical carbon dioxide (CO2) gas turbine systems can generate power at a high cycle thermal efficiency, even at modest temperatures of 500–550°C. That high thermal efficiency is attributed to a markedly reduced compressor work in the vicinity of critical point. In addition, the reaction between sodium (Na) and CO2 is milder than that between H2O and Na. Consequently, a more reliable and economically advantageous power generation system can be created by coupling with a Na-cooled fast breeder reactor. In a supercritical CO2 turbine system, a partial cooling cycle is employed to compensate a difference in heat capacity for the high-temperature — low-pressure side and low-temperature — high-pressure side of the recuperators to achieve high cycle thermal efficiency. In our previous work, a conceptual design of the system was produced for conditions of reactor thermal power of 600 MW, turbine inlet condition of 20 MPa/527°C, recuperators 1 and 2 effectiveness of 98%/95%, Intermediate Heat Exchanger (IHX) pressure loss of 8.65%, a turbine adiabatic efficiency of 93%, and a compressor adiabatic efficiency of 88%. Results revealed that high cycle thermal efficiency of 43% can be achieved. In this cycle, three different compressors, i.e., a low-pressure compressor, a high-pressure compressor, and a bypass compressor are included. In the compressor regime, the values of properties such as specific heat and density vary sharply and nonlinearly, dependent upon the pressure and temperature. Therefore, the influences of such property changes on compressor design should be clarified. To obtain experimental data for the compressor performance in the field near the critical point, a supercritical CO2 compressor test project was started at the Tokyo Institute of Technology on June 2007 with funding from MEXT, Japan. In this project, a small centrifugal CO2 compressor will be fabricated and tested. During fiscal year (FY) 2007, test loop components will be fabricated. During FY 2008, the test compressor will be fabricated and installed into the test loop. In FY 2009, tests will be conducted. This paper introduces the concept of a test loop and component designs for the cooler, heater, and control valves. A computer simulation program of static operation was developed based on detailed designs of components and a preliminary design of the compressor. The test operation regime is drawn for the test parameters.

Numerical Study of the Flow Uniformity Inside the High-Pressure Side Manifolds of a Cooled Cooling Air Heat Exchanger

2021 ◽  
Vol 189 ◽  
pp. 116645
Author(s):  
Hariharan Kallath ◽  
Foster Kwame Kholi ◽  
Qingye Jin ◽  
Man Yeong Ha ◽  
Sang Hu Park ◽  
...  
Keyword(s):  
High Pressure ◽  
Heat Exchanger ◽  
Numerical Study ◽  
Pressure Side ◽  
Flow Uniformity ◽  
Cooling Air

Practical Experience With a Mobile Methanol Synthesis Device

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Eric R. Morgan ◽  
Thomas L. Acker
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Synthesis Gas ◽  
Methanol Synthesis ◽  
Low Pressure ◽  
Practical Experience ◽  
Gaseous Hydrogen ◽  
Distillation Unit ◽  
Water Mixture ◽  
Pressure Side

A methanol synthesis unit (MSU) that directly converts carbon dioxide and hydrogen into methanol and water was developed and tested. The MSU consists of: a high-pressure side that includes a compressor, a reactor, and a throttling valve; and a low-pressure side that includes a knockout drum, and a mixer where fresh gas enters the system. Methanol and water are produced at high pressure in the reactor and then exit the system under low pressure and temperature in the knockout drum. The remaining, unreacted recycle gas that leaves the knockout drum is mixed with fresh synthesis gas before being sent back through the synthesis loop. The unit operates entirely on electricity and includes a high-pressure electrolyzer to obtain gaseous hydrogen and oxygen directly from purified water. Thus, the sole inputs to the trailer are water, carbon dioxide, and electricity, while the sole outputs are methanol, oxygen, and water. A distillation unit separates the methanol and water mixture on site so that the synthesized water can be reused in the electrolyzer. Here, we describe and characterize the operation of the MSU and offer some possible design improvements for future iterations of the device, based on experience.

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