Thermal and hydraulic design of an evaporator and condenser for a 2.5kVA Organic Rankin Cycle system

Pakistan is suffering from an acute electric power deficiency. The organic Rankine cycle (ORC) is amongst several solutions to this problem.  This technology utilizes heat transfer as its main source of energy, thus it is capable of harnessing energy from a wide variety of heat sources such as

Project Title

Thermal and hydraulic design of an evaporator and condenser for a 2.5kVA Organic Rankin Cycle system

Project Area of Specialization

Robotics

Project Summary

Pakistan is suffering from an acute electric power deficiency. The organic Rankine cycle (ORC) is amongst several solutions to this problem.  This technology utilizes heat transfer as its main source of energy, thus it is capable of harnessing energy from a wide variety of heat sources such as biomass, geothermal, solar, and waste heat energy from several processes.

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. Apart from it, the thermal and hydraulic design of the evaporator and condenser shall be designed.

Project Objectives

The research on ORCs is still ongoing. This simple yet effective technology is yet to be commercialized in main stream. The already available ORC units being produced by firms like Turboden and Ormat are very expensive. Also, these companies manufacture and commission very large scale power plants.

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

-Organic Rankine cycle study and optimization, using hot water at 100 degrees Celsius, and 1.5 atm pressure to generate 2.5 kW of energy.

-Plate Heat Exchanger design on MATLAB and SOLIDWORKS.

-Cost analysis & manufacturing of the resulting model from MATLAB (if funded)

Project Implementation Method

Implementation phase includes the use different types of softwares, like MATLAB, SOLIDWORKS, REFPROP

Details:

- Calculation of T-S diagram for the 2.5kW ORC, with the help of REFPROP software.

Working Fluid: R-134a

- MATLAB for calculating the number of plates for every phase:

Chevron type plate heat exchanger is divided into three sections, single phase liquid section, two phase liquid and vapor section, and single phase vapor section. Each section is designed separately under considered operating conditions based on log mean temperature difference method.

Initially number of thermal plates are assumed and required number of thermal plates are recalculated based on the required amount of heat transfer, LMTD and overall heat transfer coefficient. The iterative process continues until the assumed number of thermal plates are equal to recalculated
number of thermal plates.

- SOLIDWORKS for CAD model

Benefits of the Project

The modern world is constantly demanding a greater energy supply. This challenge has to overcome, at the same time, such things as the high price of oil, climate change or the destruction of the ozone layer, as well as the economic crisis. Similarly, Pakistan is suffering from an acute electric power deficiency.

The Organic Rankine Cycle (ORC) is amongst several solutions to this problem.

The benefit of this technology is that it can be manufactured locally as it involves mechanical components.

Our focus in this project is on the Evaporator and Condenser used in ORC technology. For this purpose, we selected Plate type heat exchanger.

Why Plate Type Heat Exchanger?

• High thermal efficiency for effective heat transfer
• Compact design resulting in small quantities of materials used for heat transfer surfaces
• Low installation cost
• Easy dismantling and easy, rapid cleaning
• High performance with low hold-up volume
• Versatile, modular design

Working fluid selected is R-134a because of its widespread availability in Pakistan.

We our working on our design to be used for small scale energy generation (2.5kW) using ORC technology, that can be used for houses in rural areas.

Technical Details of Final Deliverable

- Calculation of geometry of plates to be used in plate heat exchanger keeping in mind the amount of energy that has to be generated, i.e 2.5kW [MATLAB].

Following are the mathematical details;

Le=0.37m
We=0.26m
Pco=0.008m
Plate thickness=0.001m
Plate spacing b=0.003m
beta=1.047 rad (60deg)

Material: Stainless Steel

- Calculation of the number of plates needed for each phase (Liquid phase, Liquid-vapor phase, vapor phase) [MATLAB] [1].

Chevron type plate heat exchanger is divided into three sections, single phase liquid section, two phase liquid and vapor section, and single phase vapor section. 

Initially number of thermal plates are assumed and required number of thermal plates are recalculated based on the required amount of heat transfer, LMTD and overall heat transfer coefficient. The iterative process continues until the assumed number of thermal plates are equal to recalculated
number of thermal plates.

 [1] M. Imran, M. Usman, B.-S. Park, H.-J. Kim, D.-H. Lee, Multi-objective optimization of evaporator of organic Rankine cycle (ORC) for low temperature geothermal heat source,
Applied Thermal Engineering (2015), doi: 10.1016/j.applthermaleng.2015.01.034.

Final Deliverable of the Project

Hardware System

Type of Industry

Energy

Technologies

Others

Sustainable Development Goals

Affordable and Clean Energy

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com