scholarly journals Temperature Disturbance Management in a Heat Exchanger Network for Maximum Energy Recovery Considering Economic Analysis

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 594 ◽  
Author(s):  
Ainur Munirah Hafizan ◽  
Jiří Jaromír Klemeš ◽  
Sharifah Rafidah Wan Alwi ◽  
Zainuddin Abdul Manan ◽  
Mohd Kamaruddin Abd Hamid
Keyword(s):  
Heat Exchanger ◽  
Heat Recovery ◽  
Temperature Fluctuations ◽  
Maximum Energy ◽  
Pinch Analysis ◽  
Pinch Point ◽  
Maximum Heat ◽  
Capital Costs ◽  
Disturbance Management ◽  
The Impact

The design of heat exchanger networks (HEN) in the process industry has largely focused on minimisation of operating and capital costs using techniques such as pinch analysis or mathematical modelling. Aspects of operability and flexibility, including issues of disturbances affecting downstream processes during the operation of highly integrated HEN, still need development. This work presents a methodology to manage temperature disturbances in a HEN design to achieve maximum heat recovery, considering the impact of supply temperature fluctuations on utility consumption, heat exchanger sizing, bypass placement and economic performance. Key observations have been made and new heuristics are proposed to guide heat exchanger sizing to consider disturbances and bypass placement for cases above and below the HEN pinch point. Application of the methodology on two case studies shows that the impact of supply temperature fluctuations on downstream heat exchangers can be reduced through instant propagation of the disturbances to heaters or coolers. Where possible, the disturbances have been capitalised upon for additional heat recovery using the pinch analysis plus-minus principle as a guide. Results of the case study show that the HEN with maximum HE area yields economic savings of up to 15% per year relative to the HEN with a nominal HE area.

Cost–Effective Retrofit Of A Palm Oil Refinery Using Pinch Analysis

2012 ◽  
Author(s):  
Sharifah Rafidah Wan Alwi ◽  
Muhammad Azan Tamar Jaya ◽  
Zainuddin Abdul Manan
Keyword(s):  
Heat Exchanger ◽  
Palm Oil ◽  
Thermal Efficiency ◽  
Capital Investment ◽  
Heat Recovery ◽  
Cost Effective ◽  
Oil Refinery ◽  
Pinch Analysis ◽  
Heat Exchanger Network ◽  
Maximum Heat

Kilang penapisan minyak sawit lazimnya melibatkan proses penggunaan tenaga yang tinggi. Peningkatan kecekapan tenaga adalah amat penting bagi memastikan keuntungan tercapai. Kertas kerja ini menggunakan teknik analisis jepit bagi memaksimumkan penggunaan semula haba dan meningkatkan kecekapan sistem rangkaian haba sedia ada di kilang penghasilan minyak sawit, tertakluk kepada kekangan–kekangan proses. Langkah–langkah yang terlibat ialah penetapan sasaran guna semula haba maksimum diikuti dengan reka bentuk rangkaian haba yang ekonomik. Aplikasi teknik berkenaan kepada kilang penghasilan minyak sawit telah menghasilkan pengurangan penggunaan haba panas dan sejuk sebanyak 700 kW (21%), atau penjimatan kos utiliti sebanyak RM370,787, dengan pelaburan kapital sebanyak RM656,293 dan jangka pulangan balik selama 1.77 tahun. Kata kunci: Analisis jepit; minyak kelapa sawit; sedia ada; rangkaian pemindahan haba; kitar semula haba maksimum A palm oil refinery involves energy–intensive processes. Maximizing thermal efficiency of palm oil refinery is crucial for the plant profitability. This work implements a pinch analysis retrofit technique to maximize heat recovery and thermal efficiency of a palm oil refinery, subject to the existing process constraints. The procedures involve setting the maximum heat recovery targets and cost–effective retrofit of the heat exchanger network (HEN). Application of the technique on a palm oil refinery results in reduction of 700 kW (21%) heating and cooling loads or a saving of RM370,787, incurring a capital investment of about RM656,293 and a payback period of 1.77 years. Key words: Pinch analysis; palm oil; retrofit; heat exchanger network; maximum heat recovery

scholarly journals HYBRID GENETIC ALGORITHM TO THE SYNTHESIS OF OPTIMAL HEAT EXCHANGER NETWORKS

2005 ◽  
Vol 4 (1) ◽  
pp. 35
Author(s):  
M. A. S. S. Ravagnani ◽  
A . P. Silva ◽  
A. A. Constantino
Keyword(s):  
Genetic Algorithm ◽  
Heat Exchanger ◽  
Hybrid Genetic Algorithm ◽  
Second Step ◽  
Pinch Analysis ◽  
Pinch Point ◽  
Optimal Heat ◽  
Heat Exchanger Networks

In this paper a new systematic is proposed, interfacing Pinch Analysis and Genetic Algorithms (GA). Initially the optimal ∆Tmin is found by using a genetic algorithm. In a second step, with the optimal ∆Tmin, the pinch point is obtained, and the problem is divided in two regions, below and above it. The optimal HEN is obtained for each side of the pinch and the final HEN is achieved. An example from the literature was solved using the proposed systematic. Results show the applicability of the proposed methodology, obtaining a cost value lower than those presented in the literature.

Heat Exchanger Network Optimization Using Differential Evolution with Stream Splitting

2014 ◽  
Vol 625 ◽  
pp. 373-377 ◽  
Author(s):  
Ngo Thi Phuong Thuy ◽  
Rajashekhar Pendyala ◽  
Narahari Marneni
Keyword(s):  
Heat Exchanger ◽  
Differential Evolution ◽  
Network Optimization ◽  
Heat Recovery ◽  
Differential Evolution Algorithm ◽  
Main Tool ◽  
Heat Exchanger Network ◽  
Pinch Point ◽  
New Strategy ◽  
Evolution Algorithm

Reduction in energy consumption is an important task in process industry. The basic idea of heat exchanger network (HEN) is using cold streams to cool hot streams and hot streams to heat cold streams. Hence, synthesis and optimization of HEN is a main tool for improving heat recovery. This article introduces a new strategy for HEN optimization using differential evolution algorithm. The proposed method considers splitting stream at the pinch point, to minimize the total cost of the network. Primarily, the minimum approach temperature value is determined through super-targeting. Then, differential evolution is employed to specify the heat load of heat exchangers and splitting streams. The HEN structure obtained in this work has better economics and illustrates the better performance by this approach.

NUMERICAL SIMULATION AND PARAMETRIC STUDIES FOR EVALUATION OF BALANCED VENTILATION AND EARTH AIR EXCHANGERS SYSTEM COUPLED TO A DOMESTIC BUILDING

2013 ◽  
Vol 21 (01) ◽  
pp. 1350002 ◽  
Author(s):  
YOUNES KARTACHI ◽  
ABDELLAH MECHAQRANE
Keyword(s):  
Heat Exchanger ◽  
Heat Recovery ◽  
High Efficiency ◽  
Residential Buildings ◽  
Ventilation System ◽  
Primary Energy ◽  
Climatic Conditions ◽  
Design Parameters ◽  
Climate Data ◽  
The Impact

In this study, we analyze the impact of ventilation heat recovery with the heating and cooling potential of earth air heat exchanger in real climatic conditions in domestic buildings in the Middle Atlas region. In our case study, we calculate the primary energy used by a domestic building built as per the conventional house design parameters required by the Moroccan regulation. We use climate data for the city of Fes in Northern Moroccan. Three system configurations were considered. The first was the mechanical extract ventilation system both with and without heat recovery. The second was the mechanical extract ventilation system with earth to air heat exchanger system (EAHEX), and the third system was the mechanical balanced ventilation system coupled with EAHEX system. Primary energy use strongly influences natural resources efficiency and the environmental impacts of energy supply activities. In this study we explore the primary energy implications of the mechanical balanced ventilation system coupled with the EAHEX system in residential buildings. The results of this study shows that the use of a balanced ventilation system, with a high efficiency instead of a mechanical extract ventilation system, decreases the final and primary energy consumption. Moreover, it decreases or increases the CO2 emission depending on the primary energy sources.

scholarly journals Energy and economy savings in the process of methanol synthesis unsig Pinch technology

2004 ◽  
Vol 69 (10) ◽  
pp. 827-837 ◽  
Author(s):  
Mirjana Kijevcanin ◽  
Bojan Djordjevic ◽  
Ozren Ocic ◽  
Mladen Crnomarkovic ◽  
Maja Maric ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Methanol Synthesis ◽  
Heat Exchangers ◽  
Energy Savings ◽  
Energy Costs ◽  
Pinch Analysis ◽  
Trade Off ◽  
Total Cost ◽  
Capital Costs ◽  
Pinch Technology

A heat exchanger network (HEN) for the process of methanol synthesis has been studied by pinch design analysis. Great economic and energy savings were realized by the pinch analysis in comparison to the existing plant. Also, it was found that it is possible to reduce the requirements for the consumption of utilities. The HEN was reconstruded by adding new heat exchangers. In order to produce new HEN, the capital costs had to be increased, but the total cost trade-off between the capital and energy costs will be decrease by 30 %.

scholarly journals Thermal performance of the ground in geothermal pavements

2020 ◽  
Vol 205 ◽  
pp. 06015
Author(s):  
Yaser Motamedi ◽  
Nikolas Makasis ◽  
Arul Arulrajah ◽  
Suksun Horpibulsuk ◽  
Guillermo Narsilio
Keyword(s):  
Thermal Conductivity ◽  
Heat Exchanger ◽  
Thermal Response ◽  
Geothermal Heat ◽  
Capital Costs ◽  
Ground Source ◽  
Shallow Geothermal Energy ◽  
Novel Concept ◽  
Response Testing ◽  
The Impact

Shallow geothermal energy utilises the ground at relatively shallow depths as a heat source or sink to efficiently heat and cool buildings. Geothermal pavement systems represent a novel concept where horizontal ground source heat pump systems (GSHP) are implemented in pavements instead of purpose-built trenches, thus reducing their capital costs. This paper presents a geothermal pavement system segment (20m × 10m) constructed and monitored in the city of Adelaide, Australia, as well as thermal response testing (TRT) results. Pipes have been installed in the pavement at 0.5 m depth, and several thermistors have been placed on the pipes and in the ground. A TRT has been performed with 6kW heating load to achieve an understanding of the thermal response of the system as well as to estimate the effective thermal conductivity of the ground. The results show that the conventional semi-log method may be applicable to determine the thermal conductivity for geothermal pavements. The geothermal heat exchanger at shallow depth is considerably under the influence of the ambient temperature; however, it is still acceptable for exchanging the heat within the ground. It is also concluded that the impact radius of heat exchanger in geothermal pavement during the TRT is around 0.5m in the vertical and horizontal directions for this case study.

scholarly journals Financial Analysis of the Use of Two Horizontal Drain Water Heat Recovery Units

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4113 ◽  
Author(s):  
Kamil Pochwat ◽  
Sabina Kordana-Obuch ◽  
Mariusz Starzec ◽  
Beata Piotrowska
Keyword(s):  
Heat Exchanger ◽  
Water Temperature ◽  
Heat Recovery ◽  
Cold Water ◽  
Financial Analysis ◽  
Global Scale ◽  
Drain Water ◽  
Actual Distribution ◽  
Cold Water Temperature ◽  
The Impact

The growing interest in the use of unconventional energy sources is a stimulus for the development of dedicated devices and technologies. Drain water heat recovery (DWHR) units can be an example of such devices. They allow the recovery of part of the heat energy deposited in grey water. This paper describes the results of research on the assessment of the financial profitability of the use of two horizontal heat exchanger solutions, taking into account the actual distribution of cold water temperature during the operating year in the plumbing and two operating regimes of the premises as the residential and service facilities. The analysis showed that the use of a horizontal heat exchanger with increased efficiency in a dwelling in a 15-year life cycle allowed for achieving more than twice as much savings (reaching up to EUR 1427) compared to a classic horizontal heat exchanger. At the same time, it was shown that the installation of this type of equipment was more profitable the greater the water consumption of the premises. The article also notes the impact of cold water temperature in the installation on the results of the analysis. It was featured that taking temperature on the basis of installation design recommendations led to significant distortions in the financial analysis. On the other hand, comparing the method of averaging the cold water temperature (daily, monthly and yearly), it was determined that averaging the temperature over the annual cycle was an acceptable simplification of the model. The research results presented in the paper have a practical aspect and may constitute guidelines for designers and potential investors. In addition, they can be an incentive to continue research on heat exchangers by other scientific centers, which on a global scale will increase the universality of their use.

Waste-Heat Recovery in Batch Processs Using Heat Storage

1995 ◽  
Vol 117 (2) ◽  
pp. 142-149 ◽  
Author(s):  
S. Stoltze ◽  
J. Mikkelsen ◽  
B. Lorentzen ◽  
P. M. Peterson ◽  
B. Qvale
Keyword(s):  
Energy Saving ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Heat Storage ◽  
Waste Heat ◽  
Maximum Energy ◽  
Point Method ◽  
Batch Processes ◽  
Storage Tanks ◽  
Pinch Point

The waste-heat recovery in batch processes has been studied using the pinch-point method. The aim of the work has been to investigate theoretical and practical approaches to the design of heat-exchanger networks, including heat storage, for waste-heat recovery in batch processes. The study is limited to the incorporation of energy-storage systems based on fixed-temperature variable-mass stores. The background for preferring this to the alternatives (variable-temperature fixed-mass and constant-mass constant-temperature (latent-heat) stores) is given. It is shown that the maximum energy-saving targets as calculated by the pinch-point method (time average model, TAM) can be achieved by locating energy stores at either end of each process stream. This theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. A simple procedure for determining a number of heat-storage tanks sufficient to achieve the maximum energy-saving targets as calculated by the pinch-point method is described. This procedure relies on combinatorial considerations, and could therefore be labeled the “combinatorial method” for incorporation of heat storage in heat-exchanger networks. Qualitative arguments justifying the procedure are presented. For simple systems, waste-heat recovery systems with only three heat-storage temperatures (a hot storage, a cold storage, and a heat store at the pinch temperature) often can achieve the maximum energy-saving targets. Through case studies, six of which are presented, it is found that a theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. The description of these six cases is intended to be sufficiently detailed to serve as benchmark cases for development of alternative methods.

Development of Plate-Type Heat Exchanger for Exhaust Gas Heat Recovery System

2003 ◽  
Author(s):  
Hyunjae Park ◽  
Anthony Bowman ◽  
Tod Stansfield ◽  
Brian Huibregtse
Keyword(s):  
Heat Exchanger ◽  
Heat Recovery ◽  
Design Parameters ◽  
Exhaust Gas ◽  
Maximum Heat ◽  
Air Inlet ◽  
Maximum Heat Transfer ◽  
Heat Recuperation ◽  
Design Values ◽  
Plate Type

In this paper, an exhaust gas heat recuperation unit for use with a boiler is developed to improve the overall thermal efficiency of integral system. The heat recuperation unit includes a plate-type heat exchanger for exhaust gas heat recovery for exchanging heat between an exhaust gas and combustion air. A proto-type heat exchanger is designed and manufactured with a series of exhaust gas plates stacked alternatively with, and parallel to, a series of air plates. Each of the exhaust gas plates and air plates contain ridges to form a substantially sinusoidal path for directing the respective gas therealong. The combustion air flown in a countercurrent to the exhaust gas to facilitate maximum heat transfer. The heat exchanger is connected to exhaust gas inlet and outlet conduits and combustion air inlet and outlet conduits. Proper number of plates for the heat exchanger is selected to obtain laminar flow through plate flow channels, producing a low gas pressure drop in each channel. Using the proto-type heat exchanger, experimental work was primarily performed to measure temperature and pressure changes of exhaust gas and combustion air at various boiler firing conditions. These test results are compared with those obtained from numerical (CFD) and analytical works. The approximate analytical model developed in this work is used to investigate the effects of exchanger design parameters on the system performance, and eventually to develop the exchanger design curves for the optimal selection of exchanger design values.

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