This paper presents a mathematical simulation of the dynamic thermal behavior of an innovative solar bi-ejector refrigeration system with a capacity to produce cooling water. In the bi-ejector refrigeration system, the mechanical circulation pump is replaced by a vapor-liquid ejector, in order to further reduce the electricity consumption and reinforce the system feasibility. Freon R123 is the working fluid at condensing temperature of 30°C generating temperature of 85°C and evaporating temperature of 8°C The generator heat load is 10kW and an obtained evaporator cooling load is around 3kW. The whole year simulation results are presented.

Mine waterjet cutting machine is mainly used for cutting steel strands in coal mines, and can also be used for cutting anchor rods and clearing rescue channels, etc. It has no cutting sparks, no thermal deformation, smooth and intact cuts, no pollution and sufficient abrasive sources, and is complementary to other cutting technologies. The system adopts premixed abrasive water-jet cutting technology, with the working pressure of 40 MPa, mass fraction of garnet of 20%, and target distance of 3~5 mm. With the case of Φ21.8 mm steel strand, its cutting speed is 45 mm/min and feedrate is 30 m/min. Under the assumed conditions, the pressure change model shows that, to ensure the cutting quality, steel strands should be cut only after the system pressure rises to close to the working pressure after about 100 s. After the system stops operation, its pressure needs to be reduced from the working pressure to the ambient pressure after 23 s.