Pinch Technology for the Synthesis of Optimal Heat and Power Systems

1989 ◽  
Vol 111 (3) ◽  
pp. 137-147 ◽  
Author(s):  
B. Linnhoff
Keyword(s):  
Power Systems ◽  
Energy Savings ◽  
Second Law ◽  
Base Case ◽  
Process Industries ◽  
Analysis And Design ◽  
Second Law Analysis ◽  
Heat Exchanger Networks ◽  
Pinch Technology ◽  
Case Design

Over recent years a new methodology for the analysis and design of heat exchanger networks, called pinch technology, has led to significant energy savings in the chemical and process industries. The methodology has later been extended to apply to integrated heat and power systems (Townsend and Linnhoff, 1983). This paper shows that pinch technology is firmly based in Second Law Analysis. In contrast to conventional Second Law Analysis, however, it does not require a base case design. Rather, it performs true synthesis. Also, it is capable of a methodical distinction between “inevitable” and “avoidable” exergy losses.

Differences Between Second Law Analysis and Pinch Technology

1995 ◽  
Vol 117 (3) ◽  
pp. 186-191 ◽  
Author(s):  
D. A. Sama
Keyword(s):  
Heat Exchanger ◽  
Energy Recovery ◽  
Maximum Energy ◽  
Global Optimum ◽  
Second Law ◽  
Heat Exchanger Network ◽  
Second Law Analysis ◽  
Heat Exchanger Networks ◽  
Pinch Technology ◽  
Correct Design

The use of second law analysis to design a heat exchanger network is compared with the pinch technology approach. Differences between the two methods are identified and discussed in the light of claims made by practitioners of pinch technology. Second law insights are used to easily identify and correct design errors in a heat exchanger network, and to design maximum energy recovery networks. More importantly, it is found that use of the second law provides an understanding of the process which is totally absent in the pinch technology approach. The claims that pinch technology can find global optimum solutions, that only pinch technology can find maximum energy recovery heat exchanger networks, and that pinch technology is a form of second law analysis, are considered, discussed, and shown to be invalid.

Esso Energy Award Lecture, 1981 - New concepts in thermodynamics for better chemical process design

1983 ◽  
Vol 386 (1790) ◽  
pp. 1-33 ◽  
Keyword(s):  
Process Design ◽  
Heat Recovery ◽  
Industrial Applications ◽  
Second Law ◽  
Design Development ◽  
Chemical Process Design ◽  
New Concepts ◽  
Second Law Analysis ◽  
Heat Exchanger Networks ◽  
Simple Network

Most chemical processes are networks of different pieces of equipment. Usually, even the best pieces of equipment will give a poor overall process if linked up inappropriately in the network. This paper describes principles and procedures for better process network design. Development of the procedures began in 1972. In the years since, industrial applications have led to significant improvements in even the most modern processes. The paper begins with a fresh look at thermodynamic Second Law analysis. This classical analysis highlights inefficient parts of complex systems, drawing the engineer’s attention to excessive losses of potential. Unfortunately, the analysis is both difficult to produce and difficult to interpret. To tackle the first problem, the paper describes how Second Law information can be obtained from conventional heat and mass balances. There is no need for additional data. To tackle the second problem, the paper introduces a general distinction between ‘avoidable’ and ‘inevitable’ inefficiencies. This makes an interpretation of the analysis practically more meaningful. Next, the paper describes thermodynamic procedures and principles for specialized sub-tasks in process design. Emphasis is placed on heat recovery networks. Here, the problem is to recover as much heat as is economically justified within a process before externally supplied heat is used. The concept of ‘inevitable’ inefficiencies leads to techniques for the prediction of the ‘inevitable’ amount of external heating. This amount is called the energy target. The target either stimulates the engineer into achieving it or gives him confidence that his design is optimal. The paper continues by describing the concept of the heat recovery ‘pinch’. The pinch leads to the design of, first, heat exchanger networks, which achieve the energy targets, and, second, overall processes, which keep the targets low. Two common threads in all these procedures are the attempt to keep the engineer involved (they do not constitute ‘automatic’ design) and the attempt to make best practical use of inefficiencies that are ‘inevitable’ anyway. Owing to these features, the procedures usually help the engineer to find processes that are elegant in a general sense. Many designs found in practice were not only energy efficient but easily operated and maintained, safe, had relatively simple network structures and, most surprisingly, were cheap to build as well as cheap to run.

Applying Combined Pinch and Exergy Analysis to Closed-Cycle Gas Turbine System Design

1995 ◽  
Vol 117 (1) ◽  
pp. 47-52 ◽  
Author(s):  
V. R. Dhole ◽  
J. P. Zheng
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Exergy Analysis ◽  
Energy Savings ◽  
Design Guidelines ◽  
Closed Cycle ◽  
Practical Design ◽  
Pinch Technology

Pinch technology has developed into a powerful tool for thermodynamic analysis of chemical processes and associated utilities, resulting in significant energy savings. Conventional pinch analysis identifies the most economical energy consumption in terms of heat loads and provides practical design guidelines to achieve this. However, in analyzing systems involving heat and power, for example, steam and gas turbines, etc., pure heat load analysis is insufficient. Exergy analysis, on the other hand, provides a tool for heat and power analysis, although at times it does not provide clear practical design guidelines. An appropriate combination of pinch and exergy analysis can provide practical methodology for the analysis of heat and power systems. The methodology has been successfully applied to refrigeration systems. This paper introduces the application of a combined pinch and exergy approach to commercial power plants with a demonstration example of a closed-cycle gas turbine (CCGT) system. Efficiency improvement of about 0.82 percent (50.2 to 51.02 percent) can be obtained by application of the new approach. More importantly, the approach can be used as an analysis and screening tool for the various design improvements and is generally applicable to any commercial power generation facility.

scholarly journals Evaluación de irreversibilidades en un sistema de refrigeración por absorción amoniaco-agua empleando tres modelos matemáticos diferentes para calcular las propiedades termodinámicas

2018 ◽  
Vol 27 (47) ◽  
Author(s):  
Iván Vera-Romero ◽  
Christopher Lionel Heard-Wade
Keyword(s):  
Individual Component ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Second Law ◽  
Base Case ◽  
Water Mixture ◽  
Absorption Refrigeration ◽  
Second Law Analysis ◽  
Exergy Analyses

Second Law or Exergy Analyses of Absorption Refrigeration Systems (ARS) are very important for optimisations based on available work; these analyses are derived from the operating conditions and property calculations. There are several methods available for calculating the thermodynamic properties used in modelling these systems. A thermodynamic study on an ARS with the ammonia-water mixture (base case) was carried out with the objective of analysing the sensitivity of the overall and individual component irreversibility to the thermodynamic property. To this end, three existing methods were used: (M1), a model proposed by Ibrahim and Klein (1993) and used in the Engineering Equation Solver (EES) commercial software; (M2), a model proposed by Tillner-Roth and Friend (1998) and embodied in REFPROP v.8.0 developed by the National Institute of Standards and Technology (NIST); and (M3), a method proposed by Xu and Goswami (1999) that was programmed for this analysis. The obtained differences in the properties and the first law performance of the ARS are insignificant in the determination of the coefficient of performance (COP) (base case: 0.595, M1: 0.596, M2: 0.594, M3: 0.599). For the second law analysis, the overall irreversibility was the same (123.339kW) despite the irreversibilities per component had important differences: the solution heat exchanger (M1: 5.783kW, M2: 6.122kW, M3: 8.701kW), the desorber (generator) (M1: 51.302kW, M2: 45.713kW, M3: 49.098kW) and the rectifier (M1: 0.766kW, M2: 3.565kW, M3: 0.427kW). The components that destroy exergy the most are the desorber, the absorber and the condenser.

scholarly journals Analytical Assessment of (Al2O3–Ag/H2O) Hybrid Nanofluid Influenced by Induced Magnetic Field for Second Law Analysis with Mixed Convection, Viscous Dissipation and Heat Generation

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 498
Author(s):  
Wasim Ullah Khan ◽  
Muhammad Awais ◽  
Nabeela Parveen ◽  
Aamir Ali ◽  
Saeed Ehsan Awan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Viscous Dissipation ◽  
Entropy Generation ◽  
Heat Generation ◽  
Transfer Rate ◽  
Second Law ◽  
Hybrid Nanofluid ◽  
Entropy Generation Number ◽  
Generation Number ◽  
Second Law Analysis

The current study is an attempt to analytically characterize the second law analysis and mixed convective rheology of the (Al2O3–Ag/H2O) hybrid nanofluid flow influenced by magnetic induction effects towards a stretching sheet. Viscous dissipation and internal heat generation effects are encountered in the analysis as well. The mathematical model of partial differential equations is fabricated by employing boundary-layer approximation. The transformed system of nonlinear ordinary differential equations is solved using the homotopy analysis method. The entropy generation number is formulated in terms of fluid friction, heat transfer and Joule heating. The effects of dimensionless parameters on flow variables and entropy generation number are examined using graphs and tables. Further, the convergence of HAM solutions is examined in terms of defined physical quantities up to 20th iterations, and confirmed. It is observed that large λ1 upgrades velocity, entropy generation and heat transfer rate, and drops the temperature. High values of δ enlarge velocity and temperature while reducing heat transport and entropy generation number. Viscous dissipation strongly influences an increase in flow and heat transfer rate caused by a no-slip condition on the sheet.

Second Law Analysis of Spray Evaporation

1990 ◽  
Vol 112 (2) ◽  
pp. 130-135 ◽  
Author(s):  
S. K. Som ◽  
A. K. Mitra ◽  
S. P. Sengupta
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Entropy Generation ◽  
Exergy Analysis ◽  
Droplet Evaporation ◽  
Second Law ◽  
Hot Gas ◽  
Second Law Analysis ◽  
Initial Drop ◽  
Parallel Stream

A second law analysis has been developed for an evaporative atomized spray in a uniform parallel stream of hot gas. Using a discrete droplet evaporation model, an equation for entropy balance of a drop has been formulated to determine numerically the entropy generation histories of the evaporative spray. For the exergy analysis of the process, the rate of heat transfer and that of associated irreversibilities for complete evaporation of the spray have been calculated. A second law efficiency (ηII), defined as the ratio of the total exergy transferred to the sum of the total exergy transferred and exergy destroyed, is finally evaluated for various values of pertinent input parameters, namely, the initial Reynolds number (Rei = 2ρgVixi/μg) and the ratio of ambient to initial drop temperature (Θ∞′/Θi′).

Sign in / Sign up

Export Citation Format

Share Document