The thesis deals with automatic tool change in milling multifunctional machining center with horizontal spindle axis. It describes the systems that are currently in use and their base division. The first part of the work is common. In this part of the thesis is a machine design with its parameters. The second part is independent, deals with the design of the exchanger and tool magazine together with their design solution.

This development project has been carried out in collaboration with the company Hitachi Energy Sweden AB in Landskrona. Hitachi currently uses three different types of ion exchange systems, one of which is compact and is used in smaller cooling systems. Hitachi thinks that their current compact ion exchange system is too expensive and wants to find a cheaper solution, which is why the new compact ion exchange system has been developed. The development of the new compact ion exchange system has resulted in drawings and CAD models of all components, material selection and calculations to validate that the system meets the technical requirements. The new compact ion exchange system has been designed with a view to reducing the cost of manufacturing and materials, as well as assembly and service friendliness. The purpose and goal of the project was achieved.

yes / The thermal behavior of aluminium oxide-water nanofluid in a double pipe carbon steel heat exchanger was investigated in the present study. The overall heat transfer coefficient, Nusselt, and heat transfer coefficient of nanofluid were compared with the base fluid. The volume fraction of the nanoparticles was 1%. By adding nanoparticles to the fluid, the thermal properties of the base fluid improved significantly. The hot and cold fluid flow was considered counter-current, and the nanofluid was pumped into the inner tube and once into the outer tube, and the flow rate of each fluid was 0.05 kg/s. The convective heat transfer and the overall heat transfer coefficient enhanced 94% and 253% for the hot fluid flow in the outer tube and 308 % and 144% for the hot fluid flow in the inner tube, respectively. The pressure drop calculations also showed that the pressure drop would not change significantly when using nanofluid.

No / The synthesis of heat exchanger network (HEN) is a comprehensive approach to optimize energy utilization in process industry. Recent developments in HEN synthesis (HENS) present several heuristic methods, such as Simulated Annealing (SA), Genetic Algorithm (GA), and Differential Evolution (DE). In this work, DE method for synthesis and optimization of HEN has been presented. Using DE combined with the concept of super-targeting, the ΔTmin optimization is determined. Then DE algorithm is employed to optimize the global cost function including the constraints, such as heat balance, the temperatures of process streams. A case study has been optimized using DE, generated structure of HEN and compared with networks obtained by other methods such as pinch technology or mathematical programming. Through the result, the proposed method has been illustrated that DE is able to apply in HEN optimization, with 16.7% increase in capital cost and 56.4%, 18.9% decrease in energy, global costs respectively.

No / The reverse osmosis (RO) desalination process to make fresh water from seawater has been studied here. First, a model for the process is developed. Sensitivity of different operating parameters (feed flow rate, feed pressure) and design parameters (internal diameter, total number of tubes) on the recovery ratio are studied via repetitive simulation. Finally, an optimisation framework for the process is developed so as to maximize the recovery ratio or a profit function using different energy recovery devices, subjectto general constraints. The optimal operating parameters (feed flow rate, feed pressure) and design parameters (internal diameter, total number of tubes) are determined by solving the optimisation problem using an efficient successive quadratic programming (SQP) based method. The optimal values for the decision variables depend on the constraints introduced, and are also sensitive to variations in water and energy prices, as well as feed concentration. The use ofthe emerging energy recovery devices is widely justified, reporting much higher reductions in operating costs than the traditional technology used for this purpose. Using a pressure exchanger device, it is possible to reduce energy consumption by up to 50%.

Compact heat exchangers are usually characterized by a large heat transfer surface per unit of volume. These characteristics are useful when thermal energy between two or more fluids must be exchanged without mixing. Most compact heat exchangers are liquid-to-air heat exchangers, with approximately 85% of the total thermal resistance occurring on the air side of the heat exchanger. To reduce the space and weight of a compact heat exchanger, augmentation strategies must be proposed to reduce the air side resistance. However, before any strategies to augment the air side heat transfer can be proposed, a thorough insight of the current mechanisms that govern air side heat transfer is required. The tube wall heat transfer results presented in this paper were obtained both experimentally and computationally for a typical compact heat exchanger design. Both isothermal and constant heat flux tube walls were studied. For the experimental investigation, a scaled-up model of the louvered fin-tube wall was tested in a flow facility. Although computational results for the isothermal tube wall are shown, control of the experimental isothermal tube wall proved to be unrealistic and only heat transfer measurements along the constant heat flux tube wall were made. For the constant heat flux tube wall, reasonable agreement has been achieved between the measurements and the steady, three-dimensional computational predictions. The results of the study showed that high heat transfer coefficients existed at the entrance to the louver array as well as in the louver reversal region. Vortices created at the leading edge of the louvers augmented heat transfer by thinning the tube wall boundary layer. Results indicate that an augmentation ratio of up to 3 times can occur for a tube wall of a louvered fin compact heat exchanger as compared to a flat plate. / Master of Science

This study presents an optimization approach to heat exchanger network synthesis (HENS). HENs are widely used in industry and bring several fluid streams into their desired temperatures by using available heat in the process for efficient usage of energy. Our aim is to provide a network design coupled with a detailed equipment design for heat exchangers. The suggested approach involves discretization of temperatures based on heat load equalities and reformulation as a shortest-path problem, rather than dealing with a nonlinear model and a previously structured HEN, which are common methods in the literature. We generate a shortest path network whose every node corresponds to a heat exchanger alternative and each path represents a HEN design alternative. A mixed-integer nonlinear programming model is solved to design each exchanger alternative in detail, considering all thermo-physical and transport properties of streams at their temperatures and pressures. Our approach has modeling flexibility and successfully finds the required number of heat exchangers and their connections. In addition, one can control the solution quality by deciding on the heat load steps between stream inlet and outlets. Several HEN examples from the literature are solved to assess the performance of our approach and comparable results are obtained.

With increasing global energy consumption, stringent environmental protection legislation and safety regulations in industrialised nations, energy saving has been put under high priority. One of the most efficient ways of energy reduction is through heat transfer enhancement for additional heat recovery. Applying compact heat exchanger is one of the main strategies of heat transfer enhancement. However, the application of compact heat exchangers is prohibited by the lack of design methodology. Therefore, the aim of this research is to tackle the problem of developing optimisation methodologies of plate/plate-fin heat exchanger design. A mathematical model of plate-fin heat exchanger design is proposed to consider fin type selection with detailed geometry and imposed constraints simultaneously. The concept of mix-and-match fin type combinations is put forward to include all possible fin type combinations in a heat exchanger. The mixed integer nonlinear programming (MINLP) model can be converted to a nonlinear programming (NLP) model by employing continuous heat transfer and pressure drop correlations and considering the basic fin geometric parameters as continuous variables. The whole optimisation is based on volumetric minimisation or capital cost minimisation and completed by CONOPT solver in GAMS. Case studies are carried out to demonstrate the effectiveness and benefits of the new proposed methodology. For plate heat exchangers, the design methodology is developed on the basis of plate-fin heat exchanger methodology, and takes phase change, plate pattern selection, flow arrangement and pressure drop constraints simultaneously. The phase change problem is tackled by dividing the whole process into several subsections and considering constant physical properties in each subsection. The performances of various flow arrangements are evaluated by correction factors of logarithmic mean temperature difference. For two-phase conditions, the heat transfer and pressure drop performance are predicted by continuous two-phase Nusselt number and Fanning friction factor correlations to avoid the MINLP problem. The optimisation is solved by CONOPT solver as well. The feasibility and accuracy of the new proposed methodology is examined by case studies.

This master’s thesis deals with the design and manufacture of a heat exchanger with polymeric hollow fibers for a Formula Student vehicle. The work can be divided into three parts. The first part contains a review of heat transfer and heat exchangers, the second part deals with polymeric fiber heat exchangers design and manufacture of of polymeric hollow fibers heat exchanger with a heat exchanger for a Formula Student vehicle. The last part deals with the comparison of polymeric hollow fibers heat exchanger with the original aluminum heat exchanger and the evaluation of the measurement results.

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