Pinch Analysis

Latest Release: Version 1.0

Introduction

The primary application of our Pinch Analysis software is to help process engineers and managers in minimization of wasteful utilization of energy in their process plants, and to analyze and study the energy usage involved. With this software, the user can create stream-based representations of process plants (or parts of process plants) on the site, then analyze and study these process plants through several case studies in order to:

• Evaluate the inherent energy targets and understand/compare existing energy usage
• Quantify energy penalties from current energy usage and identify offending heat exchangers
• Provide insights to generate ideas for improving existing energy usage:
  • Ideas for modifying offending heat exchange steps by removing and replacing heat exchangers
  • Ideas for modifying existing heat exchangers for improved heat recovery
  • Ideas for improved design of the process itself
• Optimize existing utility usage and evaluate usage of other utilities
• Quantify benefits of integrating one or more process units and penalties resulting from area integrity constraints

Minimization of wasteful utilization of energy in process plants is only one component of energy management for the so-called Total Site. It has to be done in conjunction with (simultaneously as well as iteratively) optimization of energy generation and supply in the power plants on the site. Therefore, as shown below, we recommend using the Pinch Analysis software along with our Total Site Energy Management (TSEM) software to get the most benefit from the energy related studies.

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Pinch Analysis and Total Site Interaction

Workflow

The basic workflow in using the software consists of the following:

1. Defining the utilities (temperature, cost)
2. Entering the process stream data, as a single process plant or multiple plants, or even multiple process data
3. Determine the energy targets and utility optimization
4. Perform design case studies, and evaluate individual heat exchangers and study the effect of process modifications

A unique aspect of the software is that it allows the user to select or deselect any number of process plants or segments of a process together and study them together. This flexibility, for example, is especially useful for studying the impact of process modifications on energy usage in a quick and efficient manner.

Our software provides a flexible, hierarchical, and user-friendly platform in order to achieve this.

Main User Interface

Product Highlights: Core Functionalities

• Targeting Case Studies
  • Energy Targets
  • Utility Optimization
  • Range Targeting
• Design Case Studies
  • FCp Matrix
  • Driving Force Analysis
  • Remaining Problem Analysis

Targeting Case Studies

The first step in pinch analysis (after stream data extraction) is to determine the energy targets, i.e. hot and cold utility usage. The targeting case study functions help the user determine the targets, and additionally determine the optimal utility usage.

Energy Targets

This function enables user to evaluate the inherent energy targets for process plants, and to generate and study the composite and grand composite curves that for the process. The energy targets quantify the best we can achieve and provide a number to aim at. This functionality can also quantify the benefits of integrating one or more process units and penalties resulting from area integrity constraints.

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Composite Curves and Energy Targets

Utility Optimization

With this functionality the user can (a) determine optimal utility placements using the grand composite curve (b) optimize existing utility usage in process plants and evaluate the opportunities of and benefits from using other/additional utilities, and (c) create and study shifted balanced composite curves and balanced grand composite curve.

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Utility Optimization

Range Targeting

The choice of an optimum plant-wide ΔTmin can be determined by range targeting. The objective is to quantify how energy targets change with ΔTmin, as also utility placements, optimal usage, and optimal costs change with ΔTmin.

Design Case Studies

After determining the energy targets and appropriate utility levels, the next task is to design a new network or to determine the efficacy of the current heat exchanger network. The design case studies assist the user in this determination.

FCp Matrix

This functionality helps the user select streams that can be matched with each other at the pinch temperatures (on either side of the pinch), when designing modifications to the existing exchangers/heat exchange steps.

Driving Force Profiles

The use of this functionality is (a) to study the inherent driving force as a function of hot and/or cold composite temperatures, (b) to select the exchanger duty for streams which are matched with each other when designing modifications to the existing exchangers/heat exchange steps, and (c) to compare the operation of existing heat exchangers to the inherent driving force profile.

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Driving Force Profile and Heat Exchanger Operation

Driving Force Profiles

This case study is particularly useful for existing design study because it enables the user to identify the energy penalty from current energy usage and to identify and rank the offending heat exchangers, i.e. to visualize heat exchanger operation and the cross-pinch energy transfers (if any).

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Remaining Problem Analysis (Energy Penalty Determination)

The functionality described above is based on the well-established concepts of Pinch Technology (developed and first practiced by Professor Bodo Linnhoff and several of his co-workers in the mid-1980s) combined with the practical considerations and years of process development experience accumulated within ClearWaterBay Technology, Inc.

Additional Software Highlights

In addition to the core functionality, the Pinch Analysis software provides several special features to help the user get the best out of the software and to practice the technology. Some of the important special features are discussed here:

• Intuitive & Hierarchical Organization
• Flexibility & Focus on Insights — the software allows user to create stream-based representations of multiple process plants in any workspace, even multiple representations of the same process plant
• Handling Constant Temperature Enthalpy Changes — user can input data for streams that represent constant temperature enthalpy changes without any artificial modification to the supply or target temperatures
• Defining a Custom Utility — In addition to standard utilities such as cooling water, steam use and generation, hot oil, refrigeration, use can generate a custom utility with its own definitions.
• Water & Steam Properties — the software provides direct access to the thermodynamic properties of water and steam. The parameters and methods for calculating these properties are based on the IAPWS Industrial Formulation 1997 of the ASME steam tables (IAPWS-IF97).

The Benefits

Total Site Energy Management along with Pinch Analysis together addresses the two important problems that comprise the Total Site Analysis. There are great benefits through the integrated use of these two as, among others, the user can study:

• The interaction between the supply and demand of steam
• The optimum selection of the site-wide and local steam header levels
• The impact of plant capacity on the total site utility consumptions

How to Order

To place an order, or for more information, please contact us by phone, or by email at sales(at)cwbtech.com.