Related Experiment Video
Updated: Sep 19, 2025
08:17
Coupling Carbon Capture from a Power Plant with Semi-automated Open Raceway Ponds for Microalgae Cultivation
Published on: August 14, 2020
5.3K
Influence of engine heat source conditions on a small-scale CO2 power generation system
Ligeng Li1, Hua Tian1, Xin Lin1
1State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China.
Fundamental Research
|June 18, 2025
Summary
This study demonstrates a CO2 power system that recovers engine waste heat, reducing fuel use and emissions. The system achieved high power output and efficiency, showing stable operation under dynamic conditions.
Area of Science:
- Thermodynamics
- Waste Heat Recovery Systems
- Renewable Energy Integration
Background:
- Engine waste heat represents a significant energy loss, contributing to fuel consumption and emissions.
- Fluctuating engine operating conditions challenge the consistent performance of waste heat recovery systems.
- Developing efficient systems to capture and utilize this waste heat is crucial for improving overall energy efficiency.
Purpose of the Study:
- To experimentally evaluate a small-scale (10 kW) CO2 power generation system for waste heat recovery from engines.
- To assess the performance of key components, including a turbine expander and printed circuit heat exchanger, under various engine conditions.
- To determine the system's overall steady-state and transient performance and its potential for improving engine efficiency.
Main Methods:
- Construction and testing of a 10 kW CO2 power generation system with custom-designed turbine expander and printed circuit heat exchanger.
- Experimental performance tests conducted across a range of engine operating conditions (varying mass flow rate, temperature, and pressure).
- Analysis of steady-state and transient performance data for individual components and the integrated system.
Main Results:
- The turbine expander demonstrated stable operation under dynamic conditions, with maximum generation power and efficiency reaching 11.55 kW and 58.92%, respectively.
- The printed circuit heat exchanger effectively balanced heat transfer and pressure drop, maintaining exhaust gas pressure drop below 4 kPa.
- The integrated system achieved a maximum net power of 10.57 kW and thermal efficiency of 6.59% at specific engine conditions, improving engine brake thermal efficiency by 6.3%.
Conclusions:
- The developed CO2 power generation system effectively recovers engine waste heat, enhancing overall energy efficiency and reducing emissions.
- The system's components are capable of stable and efficient operation even with dynamic engine conditions.
- This technology offers a viable solution for improving the thermal efficiency of internal combustion engines.
Keywords:
Engine waste heat recoveryPower generationPrinted circuit heat exchangerSupercritical CO2Turbine expanderMore Related Videos
Related Concept Videos
01:10Heat Engines
3.1K
A heat engine is a device used to extract heat from a source and then convert it into mechanical work used for various applications. For example, a steam engine on an old-style train can produce the work needed for driving the train.
Whenever we consider heat engines (and associated devices such as refrigerators and heat pumps), we do not use the standard sign convention for heat and work. For convenience, we assume that the symbols Qh, Qc, and W represent only the amounts of heat transferred...
Whenever we consider heat engines (and associated devices such as refrigerators and heat pumps), we do not use the standard sign convention for heat and work. For convenience, we assume that the symbols Qh, Qc, and W represent only the amounts of heat transferred...
3.1K
01:27Otto and Diesel Cycle
2.2K
An Otto engine is a four-stroke engine that uses a mixture of gasoline and air as the working fuel. The fuel is injected into the cylinder, and the piston is moved completely down so that the cylinder is at maximum volume. By moving the piston up, adiabatic compression takes place. The spark plug ignites the gasoline-air mixture, and the burning fuel adds heat to the system at a constant volume. The heated mixture expands adiabatically and gets further cooled by exhausting heat, and this cyclic...
2.2K
01:14Mechanisms of Heat Transfer
598
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
598
01:19Mechanism of heat transfer
1.4K
Understanding heat transfer mechanisms is essential for understanding how our bodies maintain balance in different environmental conditions. When the environment is thermoneutral, the body is in a state of balance, neither using nor releasing energy to maintain its core temperature. However, when the environment is not thermoneutral, the body employs four heat transfer mechanisms to maintain homeostasis: conduction, convection, evaporation, and radiation. These mechanisms facilitate heat...
1.4K
01:30The Carnot Cycle
3.2K
Converting work to heat is an irreversible process, and the purpose of a heat engine is to reverse the effect partially. Heat engines aim to increase the efficiency of the reversal, that is, maximize the work retrieved from heat. If the efficiency of a heat engine were 100%, it would imply reversing the process completely without introducing any other effect. Thus, it would violate the second law of thermodynamics.
What could be the theoretical limit to the efficiency of a heat engine? The...
What could be the theoretical limit to the efficiency of a heat engine? The...
3.2K
01:20Mechanisms of Heat Transfer II
3.5K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
3.5K