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 ◽  
...  

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 %.

2021 ◽  
Author(s):  
Paschal Uzoma Ndunagu ◽  
Emeka Emmanuel Alaike ◽  
Theophile Megueptchie

Abstract The objective of this paper is to perform an energy optimization study using pinch analysis on the Heat Exchanger Network (HEN) of a Crude Distillation Unit to maximum heat recovery, minimize energy consumption and increase refining margin. The heat exchanger network (HEN) considered comprises exchangers from the pre-heat section of the atmospheric distillation unit, which recovers heat from the product streams to incrementally heat the crude oil feed stream before entering the furnace. This paper illustrates how to perform a detailed HEN retrofitting study using an established design method known as Pinch Analysis to reduce the operating cost by increasing energy savings of the HEN of an existing complex refinery of moderate capacity. Analysis and optimization were carried out on the HEN of the CDU consist a total of 19 heat exchangers which include: process to process (P2P) heat exchangers, heaters and coolers. In the analysis, different feasible retrofit scenarios were generated using the pinch analysis approach. The retrofit designs included the addition of new heat exchangers, rearrangement of heat exchanger (re-sequencing) and re-piping of existing exchangers. Aspen Hysys V9 was used to simulate the CDU and Aspen Energy Analyser was used to perform pinch analysis on the HEN of the pre-heat train. Several retrofit scenarios were generated, the optimum retrofit solution was a trade-off between the capital cost of increasing heat exchanger surface area, payback time, energy / operating cost savings of hot and cold utilities. Results indicated that by rearrangement (Re-sequencing), the pre-heat train can reduce hot (fired heat) and cold (air and cooling water) utilities consumption to improve energy savings by 8% which includes savings on fired heat of about 4.6 MW for a payback period of 2 years on capital investment. The results generated were based on a ΔTmin of 10°C and pinch temperature of 46.3°C. Initial sensitivity analysis on the ΔTmin indicated that variation of total cost index is quite sensitive and increases with increase in ΔTmin at the temperature range of 14.5-30°C, however total cost index remains constant and minimal at a temperature range between 10°C-14.5°C for the CDU preheat train under study. In addition, the implementation of the optimum retrofit result is straightforward and feasible with minimum changes to the existing base case/design.


Author(s):  
Majid Amidpour ◽  
Abazar Vahdat Azad

In this paper, the new approach of Constructal theory has been employed to design shell and tube heat exchangers. Constructal theory is a new method for optimal design in engineering applications. The purpose of this paper is optimization of shell and tube heat exchangers by reduction of total cost of the exchanger using the constructal theory. The total cost of the heat exchanger is the sum of operational costs and capital costs. The overall heat transfer coefficient of the shell and tube heat exchanger is increased by the use of constructal theory. Therefore, the capital cost required for making the heat transfer surface is reduced. Moreover, the operational energy costs involving pumping in order to overcome frictional pressure loss are minimized in this method. Genetic algorithm is used to optimize the objective function which is a mathematical model for the cost of the shell and tube heat exchanger and is based on constructal theory. The results of this research represent more than 50% reduction in costs of the heat exchanger.


2020 ◽  
Vol 202 ◽  
pp. 11004
Author(s):  
John Philia ◽  
Jedy Prameswari ◽  
Widayat

Methane is a highly potent greenhouse gas which contributes to the pressing global warming issue in the world. Methanol derived from methane was one of the solutions to prevent the escalating greenhouse effect. However, the process was energy intensive and hence pinch technology was used to optimize the heat efficiency in the process. This study aims to determine the optimum ΔTmin indicated with lowest total cost via HINT software. Results shown that the optimum heat exchanger configuration was obtained by network with ΔTmin 10 K, with minimum operating and capital cost of $2,729,590/year and $579,129,590/year respectively.


Author(s):  
Suneel Nagar ◽  
Ajay Singh ◽  
Deepak Patel

The objective of this study is to provide modern analytical and empirical tools for evaluation of the thermal-flow performance or design of air-cooled heat exchangers (ACHE) and cooling towers. This review consist various factors which effect the performance of ACHE. We introduced systematically to the literature, theory, and practice relevant to the performance evaluation and design of industrial cooling. Its provide better understanding of the performance characteristics of a heat exchanger, effectiveness can be improved in different operating conditions .The total cost of cycle can be reduced by increasing the effectiveness of heat exchanger.


Author(s):  
Takeshi Tsukamoto ◽  
Jyunji Takayoshi ◽  
Roger R. Schmidt ◽  
Madhusudan K. Iyengar

In 2005, IBM released a water cooled heat exchanger product that significantly enhanced data center cooling capability while also demonstrating substantial energy savings. In 2008, IBM released an enhanced water less solution to cool the electronic racks via a R410A refrigerant based vapor compression system, which is the focus of this paper. The paper provides a detailed description of device and coolant loop construction, the experimental thermal data collected, as well as a discussion of its’ cooling energy efficiency relative to both typical air cooled facilities and water cooled heat exchangers, respectively. A data center level case study was performed with experimental measurements collected and discussed herein. Significant energy savings were realized even when the heat exchanger devices were implemented on a small part of the data center. Based on the test data and the experimental data center study, the CRAC units based loops have a COP of 1.95, while the refrigerant refrigerant heat exchanger loop has a COP of 5.0.


2020 ◽  
Vol 5 (1) ◽  
pp. 76-81
Author(s):  
Shadrack Uzoma Mathew ◽  
Lebari Aban Tamzor

The research attempts to improve upon the performance efficiency of the heat exchanger network system of Pabod Brewery, Port Harcourt, Rivers State, Nigeria. It swaps the heat system of the plant by the use of Pinch Technology to recover waste heat and integrating the recovered energy for process application. The application software is Microsoft Excel and Problem Table Method was employed in the numerical analysis of data. The gross energy expenditure by the plant is 10.44MW at production capacity of 400,000 liters of beer per day. On quantitative aggregate 6.157MW goes for heating and 4.267MW for cooling. A temperature pinch or minimum approach temperature (ΔTmin)of 100C was used in the pinch analysis of the heat exchangers performance. The research findings confirmed minimum heating utility of 5.04MW and cooling utility of 3.09MW. with energy upturn of 1.08MW and 1.23MW for the hot and cold flows respectively. This correlates to energy conservation of 18% for hot utility and 21% for the cold utility. The hot stream pinch temperature is 710C while that of the cold stream is 610C. Heat exchangers network configuration design were performed above and below the pinch The network designs were produced and integrated to produce improved heat exchanger network system for the Brewery plant.


2013 ◽  
Vol 860-863 ◽  
pp. 634-638
Author(s):  
Zhi Yun Zhou ◽  
Pu Yan Zheng ◽  
Jian Gang Wang ◽  
Yan Zhou Yuan

Nowdays more and more methods for design and transformation Distributed Energy System are applied. Traditional optimization is based on the original system , by successively optimize the process in order to recovery heat as much as possible or to reduce the enery consumption . Pinch analysis can get the energy goal and expect heat exchangers number directly,according to the analysis of the users demand streams parameters cascade. In this paper, pinch analysis is applyed for the downstream heat exchanger network optimal design of the distributed energy system , and has proved that pinch analysis advantages for the distributed energy system integration.


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

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.


Author(s):  
Jinchang Liu ◽  
Pingping Zhang ◽  
Qiang Xie ◽  
Dingcheng Liang ◽  
Lei Bai

AbstractThe heat exchanger network (HEN) in a syngas-to-methanol process was designed and optimized based on pinch technology under stable operating conditions to balance the energy consumption and economic gain. In actual industrial processes, fluctuations in production inevitably affect the stable operation of HENs. A flexibility analysis of the HEN was carried out to minimize such disturbances using the downstream paths method. The results show that two-third of the downstream paths cannot meet flexibility requirements, indicating that the HEN does not have enough flexibility to accommodate the disturbances in actual production. A flexible HEN was then designed with the method of dividing and subsequent merging of streams, which led to 13.89% and 20.82% reductions in energy consumption and total cost, respectively. Owing to the sufficient area margin and additional alternative heat exchangers, the flexible HEN was able to resist interference and maintain production stability and safety, with the total cost increasing by just 4.08%.


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