» Từ khóa: evaporation

In this century, energy saving and environmental protection are the most interesting topics in scientific technology field. One of them is heat exchangers topic. Thus, nowadays, the conventional heat exchangers have been quickly replaced by microchannels heat sinks which giving smaller size and better heat transfer behaviors. Therefore, here are much researches focus on microchannels heat sinks, especially in boiling process, as present below.

 6 p hcmute 24/03/2020 373 1 Download

Từ khóa: Heat transfer, boiling, evaporation, pure water, distilled water, microchannel.

The heat transfer characteristics of a microtube evaporator use refrigerant R134a were studied experimentally. This evaporator was made from copper tubes and aluminum foils with overall dimensions (L*W*H) of 259.3*43*200mm. The evaporator has 10 passes, each pass including 8 copper pipes (with hydraulic diameter of 0.82mm) and 83 aluminum foils (with the thickness of 0.3 mm); the distance between the two foils is 2.6 mm

 8 p hcmute 23/05/2019 401 2 Download

Từ khóa: Experimental Study, Heat Transfer, R134a, MultiMicro Tubes, Evaporator.

Experiments on expansion and superheat processes of a transcritical CO2 air conditioning system were done. In this study, the cross-sectional area of the expansion valve reduces from 8.195 to 0.091 mm2, the cooler pressure increases and the evaporator pressure decreases; the pressure difference between cooler and evaporator increases

 25 p hcmute 16/05/2018 480 1 Download

Từ khóa: Experiment, CO refrigerant, expansion, superheat, evaporator, microchannel

This paper presented an experiment on a CO2 air conditioning system with copper heat exchangers. In this study, the compressor and cooler were tested with hydraulic method to determine the deformed and torn temperatures. The results show that conventional compressor is not suitable for using high pressure, due to the COP of cycle is very low (0.5 only). With CO2 compressor, the cycle can achieved COP of 3.07 at the evaporative temperature of...

 7 p hcmute 16/05/2018 545 1 Download

Từ khóa: air conditioning system, heat exchanger, cooler, evaporator, CO2 refrigerant.

The investigation presented a numerical simulation on heat transfer behaviors in microchannel evaporator of a CO2 air conditioning system. The conditions for numerical simulation were applied by the experimental data of a CO2 air conditioning cycle. This cycle worked with the cooler pressure of 85 bar, evaporator pressure of 37 bar, and the CO2 flow rate of 5.2 g/s.

 8 p hcmute 16/05/2018 579 1 Download

Từ khóa: Numerical simulation, CO refrigerant, air conditioning system, heat transfer, evaporator