Today, global energy suppliesy, economy of productions, and environment regulations controlled industry around the world. This defined a demand to save energy, reduce carbon emissions, and protect the environment for the next generation. Due to that, engineers started to come up with tools and innovations to decrease the used energy. Pinch analysis is a tool used to design heat exchanger networks (HEN) with less energy usage. This paper will focus on using entropy along with pinch analysis to design a heat exchangers network that is applicable for for today and future retrofits. and applying the second law of thermodynamics .
Pinch technology is a technology that provides a systematic methodology for energy saving in processes and plants. The methodology based onuses first low law and second law of thermodynamic, energy is conserved, and energy transfers from hot stream to cold stream. When heat exchanger is designed, the amount of heat and temperature profile must be identified for both hot stream and cold streams. The amount of the heat is related to energy conservation, and the temperature profile is related to available driving forces for heat transfer. The availability of driving force describes temperature different between the hot and cold stream. If the different is too high, the heat will exchange faster, hence less area due to the high driving force.
The pinch analysis representedrepresents all process streams in the uses Temperature-Enthalpy (T-H) diagram, composite curves diagram. The temperature axis illustrates the available driving forces for heat transferstreams driving forces for heat transfer, while the enthalpy axis illustrates shows the supply and demand ofamounts of energy. Pinch analysis will composite all energy flow of hot streams alone and cold streams alone at each temperature level. This result to have two curves which are a hot composite curve and a cold composite curve.
Then, For processes with multiple cold streams, the individual process thermal duties of them are combined into a single cold composite curve. This carve is drawn on a Temperature-Enthalpy T-H diagram, which represents the enthalpy demand profile of the process. Similarly, all the thermal duties for hot streams is combined into a single hot composite curve, which represents the enthalpy availability profile of the process.
Next step is topinch analysis defines minimum approach temperature (∆Tmin) between the two curves. It is a restricted that was derived from the second law of thermodynamic , heat transfer from hot stream to cold . stream. The optimum value of the minimum approach temperature Approach Temperature is a trade-off between operating cost savings from operating and capital cost of total area. The two curves, cold composite curve and hot composite curve, are moved horizontally and closely near each other until the closest vertical approach between them is equal to the choosing ∆Tmin. This point is called the...