Geothermal Utilization and Thermal Engineering
Consulting, Training and Teaching
on
Organic Rankine Cycle (ORC), Geothermal Flash Steam, District Heating
...just to name a few areas
My name is Páll Valdimarsson, and pvald ehf is my company.
My Chinese name, given to me by my Chinese students from the United Nations University Geothermal Training Programme, is 保罗老师, "bǎo luó lǎo shī", or "Paul the teacher" for us westerners.
I have been working in the field of Geothermal Energy for over 30 years, as a professor and in industry.
The last four years I have been Manager R&D of the "ORC Power Solutions" department of Atlas Copco Gas and Process in Cologne, Germany, making turnkey Organic Rankine Cycle power plants for geothermal and waste heat recovery applications.
Now I want to share my knowledge and experience with you by consulting, training and teaching.
News and stories are on the Facebook page.
The ORC cycle is used to produce electricity from medium enthalpy geothermal resources as well as from waste heat. The cycle has to optimized for every resource in order to minimize waste of in the plant. Special attention has to be on the presence of Non-Condensable Gas (NCG) in the source fluid.
Most geothermal power plants are flash steam plants. The plant parameters have to be optimized for the resource just as the ORC plant. The characteristics of the geothermal reservoir may change over time, so the flow of available geothermal fluid, the content of non-condensable gas in the fluid as well as the fluid enthalpy is different from what the plant was originally designed for. This will demand re-optimization of the plant.
Heating of buildings is one of the largest causes of greenhouse gas release. District heating using geothermal resource or in cogeneration of heat and power is an environmentally friendly and economical way to reduce this release. Correctly designed and optimized district heating system needs little exergy, making the valuable exergy available for power generation in cogeneration schemes.
"There is only information, if somebody is informed". A review of the governing physics and mathematics, especially as regards thermodynamics and thermoeconomics is beneficial for us all. Such courses are tailored to the needs of the geothermal professional, engineers, scientists as well as economists. Computer training brings then life to the theory by transforming the mathematics into simulation models.
A mathematical plant model and its implementation as a simulation model is just a description of reality, just as the menu in the restaurant is a description of the food offered. But a good dinner is composed of many components, and the menu has to describe these components truthfully, clearly and visually.
The production of a power plant cannot be estimated without an accurate process model.
This is needed for design, as well as for improving and troubleshooting the operating plant.
A plant model can be customized to the requirements of the plant owner, and implemented as a stand-alone program or be integrated into the SCADA system of the plant.
The model is then verified against the real plant and used for real-time optimization and "what if" analysis.
The geothermal fluid is a mixture of brine, steam and gas.
A plant model which does not take the gas into account will overestimate the available energy in the fluid as well as the plant power production.
Thermoeconomics combines exergy analysis with value analysis.
The flow of value within the plant will identify the "good" and "bad" components in the plant
=> optimization.
A little mathematical wizardry can make the T-h diagram show the exergy losses in the heat transfer in the plant and where they occur
=> optimization.
The models are either "macroscopic" - where the system is modelled as seen from the supplier,
or "microscopic" where the network flow and enthalpy is analyzed pipe for pipe, client for client.