**Abstract**

Heat exchangers are installation components in which two fluids with different temperatures are separated from each other with the help of plates and these plates make heat transfer between two fluids. The biggest advantage of plate heat exchangers over other type of heat exchangers is their heat transfer efficiency. The thinness of the plates separating the two fluids compared to other material alternatives increases the amount of heat transfer and thus reduces the heat losses that may occur during heat transfer. Plate heat exchangers are not only efficient but also prevent the formation of residue and dirt that can accumulate over time in the used applications. It also protects the system against excessive pressure that may occur in the installation. In this study, some information about plate heat exchangers is given such as classification, plate geometry, pressure losses, and thermal calculations. Also, the data obtained from the experimental work were used to obtain some relativity in order to use it in plate heat exchangers and artificial neural networks (ANN) method was used for this purpose. Artificial neural network method is used in many engineering applications. The most important advantages of this method are rapid formation, simple formation and high learning capacity.

**Keywords:** plate heat exchanger, heat transfer, artificial neural networks, thermodynamic

### **1. Introduction**

One of the most common and used processes in engineering practice is the heat exchange between two or more fluids at different temperatures. The devices in which these changes are made are generally called heat exchangers (HEX) and in practice they are used in power plants, chemical industries, heating, air conditioning, cooling, vehicles, electronic devices, use of alternative energy sources, can be found in many places. As can be seen from the above written, HEXs that is used in various applications in practice, can be used in different structures, capacities, sizes and types according to the intended use. HEXs are the most important heat transfer equipments of the industry and they can be seen in different kinds and capacities at almost every stage of chemistry, power plants, cooling, heating and air conditioning processes under different names such as evaporator, condenser, heater and cooler. From the point of view of machine and chemical engineering education, the HEXs are a very good application for this branch of science which contains all of the basic subjects of these engineering branches: materials, strength, thermodynamics and heat transfer science. As it can be understood, HEXs are always used in daily life. Thus, the design ought to be followed up to the best detail, and the nearest investigation results ought

to be gotten by utilizing related projects, and studies ought to be directed to improve the designs. Decreasing the amount of heat transferred in the HEX causes the performance of the HEX to reduce. This implies loss of performance in the energy system utilizing HEXs. The improvement of heat transfer permits the system dimensions to be kept at the proper values, thus reducing system cost and operating costs.

In the case of plate heat exchangers (PHEX), the surfaces with the basic heat transfer are made of thin metal plates. These metal surfaces might be level or wavy. They can be examined in three groups: sealed plate, spiral plate and lamellar. Heating, cooling and ventilation applications achieve the high efficiency, affordability and compact design they require thanks to PHEXs. By replacing tubular HEXs with daytime HEXs with PHEXs, PHEXs have gained a rapidly increasing market share in the entire industry. The wide selection range of plates in various sizes and materials provides superior flexibility to PHEXs. This flexibility is a great advantage for many thermal process HEXs [1].

Some correlations can be obtained using the data obtained from experimental studies and then these correlations can be used in energy applications. Artificial neural networks (ANN) method is mostly used for this purpose in energy applications. Artificial neural networks estimate the output value corresponding to this data using, data that makes up the network. It is known that artificial intelligence methodologies are used in the analysis of PHEXs as in energy systems. However, an analysis using ANN methodology for heat transfer rate and effectiveness in PHEXs for different surface angles has been performed in a small number. This study focuses on the usability of ANN methodology for performance analysis of PHEXs.

### **2. Plate heat exchangers**

In PHEXs, the surfaces with the basic heat transfer are made of thin metal plates. These metal surfaces might be level or wavy. They generally have a higher total heat transfer coefficient than shell-tube type HEXs. **Figure 1** shows the structure of a PHEX.

Plate heat exchangers; They can be examined in three groups as sealed plated, spiral plated and lamellar [1]:

a.Heat exchangers with sealed plates; Heat exchangers with sealed plates are made by packing the thin metal plates into a frame and packing them. On each side of each metal plate there are holes for fluid to pass through. When the plates are assembled and packed, using appropriate seals prevents the fluids from

**231**

**Table 1.**

*Material types of heat exchangers.*

*Plate Heat Exchangers: Artificial Neural Networks for Their Design*

intermixing and leaking out. The hot and cold fluids flow through the spaces between the plates without mixing. The plates are made wavy to provide rigidity,

b.Spiral PHEXs; Plate type heat exchangers in which heat transfer surfaces are formed from plates and not formed by cylindrical pipes. Spiral plate heat exchangers are obtained by spirally wrapping two elongated thin metal plates 150–1800 mm wide each for a fluid, forming two spiral parallel edges. A uniform clearance can be maintained between the two plates. Both sides of the plates are covered with sealed covers. Various flow configurations are possible and different types of spiral heat exchangers can be manufactured depending

to stabilize the distance between the plates and to improve heat transfer.

c.Lamellar heat exchangers; It is obtained by placing a bundle made of pipes (lamella) placed in a body. The lamella is usually held together by a point or an electric sewing source. One of the fluids flows through the lamellar tubes and flows through the other fluid lamellae. There are no surprise plates in the body. The flow is single-pass and the same direction or opposite flow arrangement can be used.

The heat exchangers are mainly regarded as pressure vessels. For this reason, the choice of design pressure, design temperature and appropriate material is crucial in the design of PHEXs. Once these criteria are established, the necessary calculations are made for the design. In the design of a PHEX, the surface A for heat transfer, the logarithmic mean temperature difference (ΔTm) and the total heat transfer coefficient

One of the factors that enable PHEXs to work without problems for long years in the desired thermal conditions is that the heat exchanger material is of a certain quality. In order for materials to be subjected to ISO 9001 quality testing, it is

It is very important to choose the plate material according to the flow rate used and the maximum desired working strength. Generally, the plate materials given in **Table 1** are used and the most commonly used material type is 1.440 / AISI 316 [2, 3].

(K), pressure drop, physical size and economics are significant factors.

**2.2 The importance of material used in plate heat exchangers**

necessary to mark each item for retrospective analysis.

AISI 304 NI 200/201 AISI 316 G-30 AISI 316 L C- 4

254 SMO INCONEL 625 654 SMO INCONEL 825 TITANYUM MONEL 400 Ti – PD TANTALUM C-276 C – 22

*DOI: http://dx.doi.org/10.5772/intechopen.95376*

on the flow configurations.

**2.1 Design of plate heat exchangers**

**2.3 Plate material**

**Figure 1.** *The structure of the plate heat exchanger [2].*

*Heat Transfer - Design, Experimentation and Applications*

for many thermal process HEXs [1].

**2. Plate heat exchangers**

spiral plated and lamellar [1]:

*The structure of the plate heat exchanger [2].*

structure of a PHEX.

to be gotten by utilizing related projects, and studies ought to be directed to improve the designs. Decreasing the amount of heat transferred in the HEX causes the performance of the HEX to reduce. This implies loss of performance in the energy system utilizing HEXs. The improvement of heat transfer permits the system dimensions to

In the case of plate heat exchangers (PHEX), the surfaces with the basic heat transfer are made of thin metal plates. These metal surfaces might be level or wavy. They can be examined in three groups: sealed plate, spiral plate and lamellar. Heating, cooling and ventilation applications achieve the high efficiency, affordability and compact design they require thanks to PHEXs. By replacing tubular HEXs with daytime HEXs with PHEXs, PHEXs have gained a rapidly increasing market share in the entire industry. The wide selection range of plates in various sizes and materials provides superior flexibility to PHEXs. This flexibility is a great advantage

Some correlations can be obtained using the data obtained from experimental studies and then these correlations can be used in energy applications. Artificial neural networks (ANN) method is mostly used for this purpose in energy applications. Artificial neural networks estimate the output value corresponding to this data using, data that makes up the network. It is known that artificial intelligence methodologies are used in the analysis of PHEXs as in energy systems. However, an analysis using ANN methodology for heat transfer rate and effectiveness in PHEXs for different surface angles has been performed in a small number. This study focuses on the usability of ANN methodology for performance analysis of PHEXs.

In PHEXs, the surfaces with the basic heat transfer are made of thin metal plates. These metal surfaces might be level or wavy. They generally have a higher total heat transfer coefficient than shell-tube type HEXs. **Figure 1** shows the

Plate heat exchangers; They can be examined in three groups as sealed plated,

a.Heat exchangers with sealed plates; Heat exchangers with sealed plates are made by packing the thin metal plates into a frame and packing them. On each side of each metal plate there are holes for fluid to pass through. When the plates are assembled and packed, using appropriate seals prevents the fluids from

be kept at the proper values, thus reducing system cost and operating costs.

**230**

**Figure 1.**

intermixing and leaking out. The hot and cold fluids flow through the spaces between the plates without mixing. The plates are made wavy to provide rigidity, to stabilize the distance between the plates and to improve heat transfer.

