Growing concerns over greenhouse gas emissions have driven extensive research into new power generation cycles that enable carbon dioxide capture and sequestration. In this regard, oxy-fuel combustion is a promising new technology in which fuels are burned in an environment of oxygen and recycled combustion gases.In this paper, an oxy-fuel combustion power cycle that utilizes a pressurized coal combustor is analyzed. We show that this approach recovers more thermal energy from the flue gases because the elevated flue gas pressure raises the dew point and the available latent enthalpy in the flue gases. The high-pressure water-condensing flue gas thermal energy recovery system eliminates the low-pressure steam bleeding which is typically used in conventional steam cycles and enables the cycle to achieve higher efficiency. The pressurized combustion process provides the purification and compression unit with a concentrated carbon dioxide stream. For the purpose of our analysis, a flue gas purification and compression process including de-SOx, de-NOx, and low temperature flash unit is examined.We compare a case in which the combustor operates at 1.1 bars with a base case in which the combustor operates at 10 bars. Results show nearly 3 percentage point increase in the net efficiency for the latter case.

The continually increasing heat generation rates in high performance electronics, radar systems and data centers require development of efficient heat exchangers that can transfer large heat loads. In this paper, we present the design of a new high-performance heat exchanger capable of transferring 1000 W while consuming less than 33 W of input electrical power and having an overall thermal resistance of 0.05 K/W. The low thermal resistance is achieved by using a loop heat pipe with a single evaporator and multiple condenser plates that constitute the array of fins. Impellers between the fins are driven by a custom permanent magnet synchronous motor in a compact volume of 0.1 × 0.1 × 0.1 m to maximize the heat transfer area and reduce the required airflow rate and electrical power. The design of the heat exchanger is developed using analytical and numerical methods to determine the important parameters of each component. The results form the basis for the fabrication and experimental characterization that is currently under development.Index Terms-Air cooling, heat exchanger, loop heat pipe, thermal management.

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