The thermodynamic performance of a proposed split-type vapor compression refrigerator (SVCR) for heat hazard control in a deep mine was numerically analyzed. The thermodynamic characteristics of the suction process of the proposed system were also simulated and analyzed. In the suction direction, the pressure, velocity, temperature, and specific enthalpy of R134a vapor dropped, whereas its specific volume and specific entropy rose. The variations in the superheat of the compressor inlet and the characteristics of the pressure drop of the suction process were also described in detail and analyzed. For comparison with the theoretical cycle, a variable, c, defined as the COP ratio of the proposed system and the theoretical cycle, was presented, and the variations of c were studied and discussed in detail. The proposed system was compared with a cooling water system and an ice slurry system, and results indicate that the thermal performance of the proposed system is better than that of the cooling water system. The thermal performance of the ice slurry system is better than that of the proposed system when a mine is sufficiently deep. However, when the mine is not too deep and the evaporation temperature, T_E, is not too low, the proposed SVCR system is the better choice.

Conclusion

This study proposes the SVCR system for heat hazard control in deep mines. The thermodynamic characteristics of the suction process and the thermal performance of the entire system are simulated and analyzed in detail. The following major conclusions can be drawn from the simulation results:

(1) In the suction direction, p, u, T, and h of R134a vapor drop, whereas v and s rise. The superheat Tsh,5 increases with a decrease in H and Q₀ and an increases in N, d, T_E, and T_sh,4.

(2) The pressure drop △p grows with an increase in T_E and a decrease in Q₀, N, d, and T_sh,4. The pressure drop △p₁ grows with an increase in H, Q₀, N, d, and T_E and a decrease in T_sh,4. The pressure drop △p₂ grows with an increase in H and a decrease in Q₀, N, d, T_E, and T_sh,4.

(3) The COP ratio c grows with an increase in N, d, and T_C and a decrease in H, Q₀, and T_E. This finding suggests that the values of N and d should be designed rationally.

(4) The overall thermal performance of the SVCR system is better than that of the cooling water system. When the mine is sufficiently deep, the thermal performance of the ice slurry system is better than that of the SVCR system. However, when the mine is not too deep and T_E is not too low, the SVCR system is the better choice.

The results have been published on Applied Thermal Engineering 105 (2016) 425–435.