Abstract: Provided are a hybrid engine system capable of protecting an engine from overspeeding when the load of a generator rapidly decreases, and a method of controlling the hybrid engine system. The hybrid engine system includes: an engine; a generator driven by the engine to output electrical energy; a battery configured to store electrical energy produced by the generator or supply electrical energy together with the generator; and a controller configured to control the engine, wherein the controller includes a torque meter for measuring torque of an output shaft of the engine and a current meter for measuring output current of the generator, and is further configured to change a control mode of the engine when a reduction rate of at least one of the torque and the current is greater than a set value while the engine is operating in a fly mode.

Abstract: Provided is a heat exchanger heat transfer enhancement device, and in particular, to a heat exchanger heat transfer enhancement device by allowing a fluid flowing into a heat exchanger to form a uniform flow field. A flow distribution device is disposed at an inlet of a pipe through which a fluid is introduced, and the flow distribution device includes a plurality of holes formed on a circumferential surface and an end portion to distribute the fluid to the center and the periphery. Also, a flange is formed at one end and coupled between the pipe and a diffusion portion. The distributed fluid passes through a heat exchanger, and here, one or more screens are disposed to make a flow field of the fluid more uniform.

Abstract: Provided is a heat exchanger heat transfer enhancement device, and in particular, to a heat exchanger heat transfer enhancement device by allowing a fluid flowing into a heat exchanger to form a uniform flow field. A flow distribution device is disposed at an inlet of a pipe through which a fluid is introduced, and the flow distribution device includes a plurality of holes formed on a circumferential surface and an end portion to distribute the fluid to the center and the periphery. Also, a flange is formed at one end and coupled between the pipe and a diffusion portion. The distributed fluid passes through a heat exchanger, and here, one or more screens are disposed to make a flow field of the fluid more uniform.

Abstract: Provided is a cooler and an engine testing apparatus having the same. The cooler includes a guide unit configured to make a gas flow, a liquid supply unit arranged in the guide unit to supply a liquid into the guide unit, a liquid column guide unit connected to the guide unit and having a column of the liquid, and a liquid storage unit connected to the liquid column guide unit and storing the liquid.

Abstract: Provided is a cooler and an engine testing apparatus having the same. The cooler includes a guide unit configured to make a gas flow, a liquid supply unit arranged in the guide unit to supply a liquid into the guide unit, a liquid column guide unit connected to the guide unit and having a column of the liquid, and a liquid storage unit connected to the liquid column guide unit and storing the liquid.

Abstract: As a component of an aerial vehicle, a power management system having an active power control device is provided. The system includes a solar cell converting solar energy into electric energy; a fuel cell provided in the aerial vehicle and converting fuel energy into electric energy by electrochemical reaction; a battery compensating for a lack of electric power supplied from the solar cell and the fuel cell to the aerial vehicle and storing surplus electric power; and an active power control device connecting with all the solar cell, the fuel cell and the battery and combining and distributing electric power generated in the solar cell, the fuel cell and the battery to loads. The system efficiently distributes the power from the respective power sources through the controllable output of the fuel cell in accordance with power required by the aerial vehicle and the solar cell's performance depending on weather.

Abstract: As a component of an aerial vehicle, a power management system having an active power control device is provided. The system includes a solar cell converting solar energy into electric energy; a fuel cell provided in the aerial vehicle and converting fuel energy into electric energy by electrochemical reaction; a battery compensating for a lack of electric power supplied from the solar cell and the fuel cell to the aerial vehicle and storing surplus electric power; and an active power control device connecting with all the solar cell, the fuel cell and the battery and combining and distributing electric power generated in the solar cell, the fuel cell and the battery to loads. The system efficiently distributes the power from the respective power sources through the controllable output of the fuel cell in accordance with power required by the aerial vehicle and the solar cell's performance depending on weather.