mass transfer

Energy and environment has been issues concerned all over the world. In China, the application of small size gas-fired air-cooled air-conditioner as an alternative for electric compression air conditioning systems has shown broad prospects due to occurrence of electricity peak demand, lack of water resources and environment-friendly working pairs. Especially, the new air-cooled air-conditioner has many advantages. In order to evaluate its cycle performance, the mathematical model of the new air-conditioner was presented.

The three-dimensional heat transfer performance of the slotted light steel-framed composite wall atminimum temperature is simulated using the finite element software of ANSYS. Based on the simulatedresults of heat transfer and the theory of moisture permeation, moisture transfer of the composite wall iscalculated. The results show that there is no condensation at the inner wall surface at the minimumtemperature in Harbin when the thickness of the wall is 229mm. The condensation may occur in the rockwool near the outer wall.

The paper presents a method of designing thermal comfort conditions in a room with an UnderFloor Air Distribution system (UFAD). A two-phase algorithm is based on: a steady or unsteady heat and mass transfer theory in the first step of computation and thermal comfort calculation in the second step. This method is implemented as the computer program UFAD_NET.