TABLE OF CONTENTS In this section, we will present the key concepts of pinch analysis, showing how it is possible to set energy targets and achieve them with a network of heat exchangers. These concepts will then be expanded for a wide variety of practical situations in the following chapters.
Consider the simple process shown in Figure 2.1. There is a chemical reactor, which will be treated at present as a "black-box". Liquid is supplied to the reactor and needs to be heated from near-ambient temperature to the operating temperature of the reactor. Conversely, a hot liquid product from the separation system needs to be cooled down to a lower temperature. There is also an additional unheated make-up stream to the reactor.
Any flow which requires to be heated or cooled, but does not change in composition, is defined as a stream. The feed, which starts cold and needs to be heated up, is known as a cold stream. Conversely, the hot product which must be cooled down is called a hot stream. Conversely, the reaction process is not a stream, because it involves a change in chemical composition; and the make-up flow is not a stream, because it is not heated or cooled.
To perform the heating and cooling, a steam heater could be placed on the cold stream, and a water cooler on the hot stream. The flows are as given...
