scholarly journals Design of Robust PI Controller for Counter-Current Tubular Heat Exchangers

2013 ◽  
Vol 6 (2) ◽  
pp. 235-239 ◽  
Author(s):  
Jana Závacká ◽  
Monika Bakošová
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Controller Design ◽  
Cold Water ◽  
Stability Boundary ◽  
Parametric Uncertainty ◽  
Volumetric Flow Rate ◽  
Pi Controller ◽  
Control Input ◽  
Counter Current

Abstract The paper presents an approach for robust PI controller design for a system affected by parametric uncertainty. The method is based on plotting the stability boundary locus in the plane of controller parameters that is called (kp, ki)-plane. Designed robust PI controller is implemented for control of two counter-current tubular heat exchangers in series with uncertain parameters, in which kerosene as a product of distillation in a refinery has to be cooled by water. The controlled variable is the temperature of the outlet stream of the kerosene from the second heat exchanger and the control input is the volumetric flow rate of the inlet stream of the cold water in the second heat exchanger. Simulation results of robust PI control of heat exchangers are also presented.

scholarly journals Robust controller design for a heat exchanger using ℋ2, ℋ∞, ℋ2/ℋ∞, and μ-synthesis approaches

2016 ◽  
Vol 9 (2) ◽  
pp. 184-193 ◽  
Author(s):  
Anna Vasičkaninová ◽  
Monika Bakošová
Keyword(s):  
Heat Exchanger ◽  
Controller Design ◽  
Volumetric Flow Rate ◽  
Hot Water ◽  
Control Input ◽  
Robust Controllers ◽  
Robust Controller ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Robust Controller Design

Abstract Possibilities of using robust controllers for a shell-and-tube heat exchanger control were studied, tested and compared by simulations and obtained results are presented in this paper. The heat exchanger was used to pre-heat petroleum by hot water; the controlled output was the measured output temperature of the heated fluid — petroleum, and the control input was the volumetric flow rate of the heating fluid — water. Robust controllers were designed using ℋ2, ℋ∞, ℋ2/ℋ∞ strategies and μ-synthesis. A comparison with the classical PID control demonstrated the superiority of the proposed robust control especially in case when the controlled process is affected by disturbances.

scholarly journals Simulation of the effectiveness of longitudinal rectangular fins on the efficiency of the double pipe heat exchanger

2019 ◽  
Vol 21 (4) ◽  
pp. 48-57
Author(s):  
N. F. Timerbaev ◽  
A. K. Ali ◽  
Omar Abdulhadi Mustafa Almohamed ◽  
A. R. Koryakin
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cold Water ◽  
Tube Diameter ◽  
Hot Water ◽  
Outer Tube ◽  
Design Parameters ◽  
Double Pipe ◽  
Central Pipe ◽  
Pipe Heat

In this article, a mathematical simulation of a double pipe heat exchanger is carried out, having the longitudinal rectangular fins with the dimension of (2*3*1000) mm, mounted on the outer surface of the inner tube of the heat exchanger. In this paper, the advantage of using of that type of fins and its effect on the effectiveness of the heat exchanger are studied with the help of the computer program. The carried out research allowsmaking the calculation to find the optimum design parameters of heat exchangers. The outer tube diameter is (34.1mm) while the inner tube diameter is (16.05mm). The tubes wall thickness is (1.5mm) and the model length was (1 m). The hot water is flowing through the inner tube in parallel with the cold water that passing the outer tube. The hot and cold water temperature at the inlet is (75°C & 30°C) respectively. The mass flow rate inside the central pipe is (0.1 kg/s) while the annular pipe carrying (0.3 kg/s). In the present work, the program ANSYS Workbench 15.0 was used to find out the results of heat transfer as well as the behavior of liquids inside the heat exchangers.

scholarly journals PENGARUH DEBIT TERHADAP UNJUK KERJA ALAT PENUKAR KALOR DAN PENURUNAN SUHU RUANGAN

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Mirmanto Mirmanto ◽  
I Made Adi Sayoga ◽  
Zulkarnain Zulkarnain
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Room Temperature ◽  
Rapid Development ◽  
Volumetric Flow Rate ◽  
Working Fluid ◽  
Flow Rates ◽  
Pressure Drops ◽  
Growth Industry ◽  
Pipe Heat

ABSTRACTDue to population growth, industry advance and rapid development, fresh and comfortable air may be difficult to get. Conditioning the air to get comfort environment may be a basic demand for people, but the prices of the device and its operation for this purpose are expensive. This research tries to solve this problem but it is just only to know the capability of the heat exchanger  to transfer/ absorb heat and is not to cool the room to be below the ambient temperature. The working fluid used was clean water and the heat exchangers employed were parallel and serpentine which were made of copper pipes with a diameter of 1/4 inch and 1/2 inch (for the header). The volumetric flow rates used were 300 ml/minutes, 400 ml/minutes and 500 ml/minutes. While the heat that should be absorbed by the water from the room is 50 W, 100 W and 150 W. The results show that the effect of volumetric flow rate on heat exchanger performance and room temperature is insignificant. From the pressure drop results, the parallel pipe heat exchanger has lower pressure drops while the serpentine has higher pressure drops. 

scholarly journals Output Feedback Adaptive Sliding Mode Control Design for a Plate Heat Exchanger

2018 ◽  
Vol 21 (4) ◽  
pp. 549-555
Author(s):  
Shibly Ahmed Al-samarraie ◽  
Luma F. Ali
Keyword(s):  
Heat Exchanger ◽  
Cold Water ◽  
Sliding Mode ◽  
Time Derivative ◽  
Hot Water ◽  
Adaptive Sliding Mode Control ◽  
Sliding Mode Controller ◽  
Control Input ◽  
Adaptive Sliding Mode ◽  
Adaptation Law

The heat exchanger is a device used to transfer heat energy between two fluids, hot and cold. In this work, an output feedback adaptive sliding mode controller is designed to control the temperature of the outlet cold water for plate heat exchanger. The discontinuous gain value of the sliding mode controller is adapted according to a certain adaptation law, where the only information required is the measurement of the outlet cold temperature. A sliding mode differentiator was design to estimate time derivative of outlet hot water temperature. Two constraints which imposed on the volumetric flow rate of the hot water (control input) were considered within the rules of the proposed adaptation law in this work. These are the control input is positive only and has a maximum value. For constructing the sliding variable, the outlet hot water temperature and its time derivative are required. The maximum allowable desired outlet cold water has been estimated as function of heat exchanger parameters and maximum control input. The simulation results demonstrate the performance of the proposed adaptive sliding mode control where the outlet cold water was forced to follow desired temperature equal to . Additionally, the robustness of the proposed controller was tested for the case where the cold inlet temperature is not constant. The results reveal the robustness of the proposed controller.

scholarly journals Heat Transfer Enhancement of Circular- and Petal- Shaped Double-Tube-Type Heat Exchangers by Triple Ones

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6590
Author(s):  
Toshihiko Shakouchi ◽  
Kazuma Yamamura ◽  
Koichi Tsujimoto ◽  
Toshitake Ando
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Cold Water ◽  
High Heat ◽  
Hot Water ◽  
Compact Heat Exchangers ◽  
Heat Transfer Efficiency ◽  
High Heat Transfer ◽  
Tube Type ◽  
Counter Current

Conventional circular double or triple tube type heat exchanger, DHE or THE, is one of the compact heat exchangers; a large number of studies have been performed to improve their heat transfer performance. The authors demonstrated that a petal-shaped special DHE with a large wet perimeter yields a high heat transfer efficiency, η. In this study, the DHE with six or five petals-, five shallow petals-, and circular-inner tubes were used. To further improve the η of the DHE, a THE with a petal-shaped inner tube along with the middle and outer circular tubes were used. Hot water flowed through the inner tube and cold water flowed through the middle and outer tubes as a counter current flow. The heat transfer was approximately equal; however, the flow resistance (pressure loss) of the outer tube of the DHE could be decreased using the middle and outer tubes under the same amount of cold water as the DHE; consequently, the η could be improved. In addition, the effect of changing the flow path of the hot- and cold-water flows on the η was examined.

scholarly journals Residential Drain Water Heat Recovery Systems: Modeling, Analysis, and Implementation

2010 ◽  
Vol 5 (3) ◽  
pp. 85-94 ◽  
Author(s):  
Scott Bartkowiak ◽  
Ryan Fisk ◽  
Andrew Funk ◽  
Jonathan Hair ◽  
Steven J Skerlos
Keyword(s):  
Heat Exchanger ◽  
Natural Gas ◽  
Flat Plate ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Cold Water ◽  
Hot Water ◽  
Published Data ◽  
Drain Water ◽  
Water Heaters

This paper describes the design and environmental improvements that can be achieved using drain water heat recovery systems (DWHR) to reduce the energy consumption associated with residential showering. DWHR systems transfer heat from hot drain water to the shower's incoming cold water stream, thus reducing the demand on the hot water heater. There are various DWHR systems available that differ in heat exchanger type, cost, and performance. This article focuses on designing a flat plate and gravity fed heat exchangers for a range of residential showering conditions. This is useful since there currently is no peer-reviewed published data on the effectiveness of DWHR, nor is there published research considering the emissions reductions that can be achieved with realistic DWHR systems. The governing equations for heat exchangers are used to model empirical data and to derive implementation recommendations for DWHR design. The model is validated using a prototype flat plate heat exchanger and test stand under varying flow rates and temperatures. A Monte Carlo simulation of the results showed that DWHR could save an average $74 a year for homes with natural gas water heaters and $160 a year for homes with electric water heaters. This corresponds to 0.3 metric tons and 1.5 metric tons of CO2offset per home per year for natural gas and electric water heaters, respectively. The results are compiled and organized into a software program that allows consumers to input their household showering habits and location to get an estimate of their CO2, energy, and cost savings to determine if they should install a DWHR system.

scholarly journals Numerical Simulation of Heat Exchanger for Analyzing the Performance of Parallel and Counter Flow

2021 ◽  
Vol 16 ◽  
pp. 145-152
Author(s):  
Farid Ahmed ◽  
Md Minaruzzaman Sumon ◽  
Muhtasim Fuad ◽  
Ravi Gugulothu ◽  
AS Mollah
Keyword(s):  
Numerical Simulation ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Cold Water ◽  
Hot Water ◽  
Shell Side ◽  
Counter Flow ◽  
Tube Heat Exchanger ◽  
Shell And Tube

Heat exchangers are almost used in every industry. Among them, shell and tube heat exchangers are covering around 32% of the total heat exchanger. Numerical simulation of the Computational models is playing an important role for the prototypes including the Heat Exchanger Models for the improvement in modeling. In this study, the CFD analysis of parallel and counter flow shell and tube heat exchanger was performed. Following project, looked into the several aspects and these are the temperature, velocity, and pressure drop and turbulence kinetic energy along with the heat exchanger length. Hot water was placed in tube side and cold water was placed in shell side of the heat exchanger. Shell side cold temperature was increasing along the heat exchanger length. On the other side, tube side hot water temperature was decreasing along the tube length. This effect was more significance in counter flow rather than the parallel flow. Velocity was more fluctuating in the shell side due to presence of the baffles. Also following the same reason, pressure drop was higher in the shell side cold water rather than the tube side hot water. To measure the turbulence effect, turbulence kinetic energy was determined. Turbulence was decreasing first part of the shell and tube heat exchanger. But, it was increasing along through the rest part heat exchanger. All these observations and the outcomes are evaluated and then further analyzed

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