An improved design method for retrofitting industrial heat exchanger networks based on Pinch Analysis

Chemical processes are energy intensive industries; the majority of energy consumed in industrial processes is mainly used for heating and cooling requirements. This results in increasing the interest in obtaining the optimum design of the heat exchanger networks to reduce the energy consumption and face the growing energy crises. Most of the published literature over the last fifty years promotes the process integration technology as a main part of the process system engineering science. Graphical Pinch Analysis method normally includes two key steps, firstly obtaining the energy targets which include the minimum energy required for the HEN design, then designing the heat exchanger network (HEN). This paper introduces a new graphical approach for the design of new heat exchanger networks (HENs) based on pinch analysis rules. The HEN is represented on a simple graph, where the cold stream temperatures are plotted on the X-axis while the driving forces for each exchanger are plotted on the Y-axis. This graphical technique can describe the energy analysis problems in term of temperature driving force inside the heat exchanger, which is an important factor in the design process as the differences in these driving forces are involved in calculating the area of heat exchangers, and consequently affecting the cost.

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HYBRID GENETIC ALGORITHM TO THE SYNTHESIS OF OPTIMAL HEAT EXCHANGER NETWORKS

Revista de Engenharia Térmica ◽

10.5380/reterm.v4i1.3546 ◽

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.

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The Use of the Second Law of Thermodynamics in Process Design

Journal of Energy Resources Technology ◽

10.1115/1.2835338 ◽

1995 ◽

Vol 117 (3) ◽

pp. 179-185 ◽

Cited By ~ 19

Author(s):

D. A. Sama

Keyword(s):

Heat Exchanger ◽

Design Procedure ◽

Second Law Of Thermodynamics ◽

Global Optimum ◽

Second Law ◽

Complex Processes ◽

Cost Of Energy ◽

Heat Exchanger Networks ◽

Improved Design ◽

Optimum Solution

The importance of using the second law of thermodynamics in the design of heat exchangers, heat exchanger networks, and processes in general, is discussed. The optimal ΔT at a refrigerated heat exchanger is considered from a second law viewpoint. It is shown that the use of minimum total annualized cost as the single optimizing factor is unsatisfactory. Total annualized costs are based on predicted costs of fuel, equipment, and capital, which are uncertain at best. Instead of a singular or “global optimum” ΔT, there is a range of optimal ΔTs, over which the total annualized cost is essentially the same, but within which the distribution between cost of capital and cost of energy is significantly different. In selecting a design ΔT, this distribution of costs should also be considered. The possibility of only one singular, or global optimum, solution for complex processes is also considered from a philosophical viewpoint, and is again rejected. The existence and identification of design decisions which unnecessarily waste thermodynamic availability (physical exergy) are discussed and identified as “second law errors.” Elimination of a second law error from a design guarantees an improved design. An optimal design, which may be any one of a numerous set of optimal designs, will result when all second law errors are eliminated. A design procedure to develop optimal process designs, using such thermodynamic insights, is proposed.

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The New Pinch Design Method for Heat Exchanger Networks

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.1253 ◽

2012 ◽

Vol 512-515 ◽

pp. 1253-1257 ◽

Cited By ~ 2

Author(s):

Fei Long Zhang ◽

Shu Rong Yu ◽

Ling Shen ◽

Qiu Ping Zhao

Keyword(s):

Heat Capacity ◽

Heat Exchanger ◽

Heat Loss ◽

Design Method ◽

Location Choice ◽

New Method ◽

Heat Exchanger Network ◽

Heat Exchanger Networks

a new method of locating the pinch is presented for the design of heat exchanger networks. The method is based on the pinch design method for heat exchanger networks which was first introduced by Linnhoff. The method first consider both the heat loss of a hot stream and the heat capacity flowrate of a stream with variation in temperature in the design of heat exchanger networks. Which affect not only minimum utility requirement for heat exchanger network but also the pinch location, choice ofΔTmin

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The Pinch Design Method for Heat Exchanger Networks Considering the Heat Capacity Flowrate of a Stream with Variation in Temperature

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.396-398.1048 ◽

2011 ◽

Vol 396-398 ◽

pp. 1048-1054

Author(s):

Fei Long Zhang ◽

Shu Rong Yu ◽

Ling Shen

Keyword(s):

Heat Capacity ◽

Heat Exchanger ◽

Design Method ◽

Location Choice ◽

Heat Exchanger Network ◽

Heat Exchanger Networks ◽

Novel Method

a novel method of locating the pinch is presented for the design of heat exchanger networks. The method is based on the pinch design method for heat exchanger networks which was first introduced by Linnhoff. The method first consider the heat capacity flowrate of a stream with variation in temperature. This is because heat capacity flowrate of a stream with variation in temperature not only affect minimum utility requirement for heat exchanger network but also affect the pinch location, choice ofΔTmin.

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