Thermal design of a Turbine for a 2.5 kVA Organic Rankine Cycle system

Project Title

Project Area of Specialization

Shared Economy

Project Summary

The electrical deficiency of Pakistan is one of the major concern. The organic Rankine cycle (ORC) is a technology that can help in easing this pressing concern. This technology holds the ability to harness heat from various heat sources, such as biomass, solar, geothermal, waste heat, and even combinations of them. The main attraction for this technology is that it can be produced using indigenously available sources. Unlike other semi-conductor based technologies which involve expensive materials and manufacturing techniques, it is a cost effective solution.

The ORC has four major components namely, evaporator, condenser, pump, and an expander. In this project we aim to optimize a cycle using hot water at 100 degrees Celsius, and 1.5 atm pressure to generate 2.5 kW of energy considering the ambient conditions of Karachi in accordance with American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) weather data. Lastly, the major step of this project involves the thermal design and optimization for turbine for the ORC.

Project Objectives

The research on ORCs is still under process particularly at small scale. This simple yet effective technology is still under the process of being commercialized at small scale. The available ORC units being produced are very expensive and would not be economically viable for a poor country like Pakistan.

Our objective is to develop cost friendly solutions considering the Pakistan’s economy and aim at its component of turbine design for small scale applications.

1-Preliminary design of radial inflow turbine

2-CAD model of radial inflow turbine

3-CFD analysis of turbine on ANSYS 16.0

4-Physical model(optional) of turbine if funds approved

Project Implementation Method

1-Preliminary design of radial inflow turbine using MATLAB iterative techniques. This can be done by using data carried out from the literature reviews of different journel papers[1] and we are also following a book[2] for this purpose.

2-After getting the geometry parameters of turbine we will make the CAD model of radial inflow turbine on SOLID WORKS 2018 by the help of mean line model or 0D model that we have calculated through MATLAB.

3-After completing the CAD model of the turbine on SOLID WORKS we will then import the CAD model on ANSYS 16.0 for the CFD analysis of turbine using turbulence modeling(RANS method) and different FEA techniques.

4-Once all the CFD analysis has been done then we will finally move towards making the physical model of the Radial Inflow Turbine.

[1]Do-Yeop Kim, You-Taek Kim, Preliminary Design and Performance Analysis of a Radial Inflow Turbine for Organic Rankine Cycles, Applied Thermal Engineering.2017.04.020.

[2] The Design of High Efficiency Turbomachinery and Gas Turbines. By David Gordon Wilson and Theodosios Korakianitis, 2nd Edition.

Benefits of the Project

Pakistan is constantly demanding a greater energy supply and ORC technology is very suitable for this because:

Its ease of manufacturing in Pakistan as it involves metal work only.
Versatility of fuel as any heat source can be utilized even waste heat.
Readily available resources
low cost of maintainence

Our goal is to design more efficient turbine to generate a good amount of Net Workdone.

WHY Radial Inflow Turbine?

Compared to an axial flow turbine, a radial turbine can employ a relatively higher pressure ratio (?4) per stage with lower flow rates. Thus these machines fall in the lower specific speed and power ranges.

The flow in a radial inflow turbine is as the name implies, in a radial direction, towards the center of the rotor. These turbines are sometimes built with cantilever blades, so that both the inflow and outflow from the rotor blades are in a radial direction. The 90 degrees radial inflow turbine is more common, where there is a 90 degrees change of flow direction in the rotor, and the flow leaves the rotor in an axial direction. The radial inflow turbine is very common. The diesel engine turbocharger is usually a radial inflow turbine mounted back to back to a radial outflow compressor. A small turbocharger will have very high rotational speed, but as both the turbine and the compressor are similar components with similar dimensions, they can be designed for a common (high) rotational speed. Even the hydraulic Francis turbine, found in hydroelectric power plants all over the world is a radial inflow turbine.

Technical Details of Final Deliverable

In order to develop a general procedure it will be assumed initiallythat only the desired power output is specified.If the required power output, mass flow rate and inlet stagnation temperature are known then Scan be calculated directly. If, however, only the power output is known then S must be specified and the design analysis used to select an appropriate magnitude; this may be an iterative procedure. Once a magnitude of power ratio has been determined the required mass flow rate follows for any specified inlet stagnation temperature, which is usually limited by rotor material and stress capabilities.The design procedure will therefore be developed from a specification of the power ratio.