Auto cascade refrigeration(ACR) cycle with phase separators is widely used in the cryogenic system. The composition of mixed refrigerant has a great effect on the performance of the system. Based on the assumption of ...Auto cascade refrigeration(ACR) cycle with phase separators is widely used in the cryogenic system. The composition of mixed refrigerant has a great effect on the performance of the system. Based on the assumption of infinite volume of phase separator, ACR system with one phase separator is simulated in this paper. The variation of refrigerant composition under different valves opening is obtained. A related experimental system is set up to verify the variation. The result shows that when the valve opening connected to the evaporator increases or the valve opening under the phase separator decreases, the low-boiling component concentration of the working mixture passing through the compressor and condenser increases, while the high-boiling component concentration decreases. Furthermore, the variations of condensation pressure and evaporation pressure under different valves opening are also observed. This paper is helpful to deepen the understanding of ACR system.展开更多
By using cone expansion-compression theorem in this paper, we study boundary value problems for a coupled system of nonlinear third-order differential equation. Some sufficient conditions are obtained which guarantee ...By using cone expansion-compression theorem in this paper, we study boundary value problems for a coupled system of nonlinear third-order differential equation. Some sufficient conditions are obtained which guarantee the boundary value problems for a coupled system of nonlinear third-order differential equation has at least one positive solution. Some examples are given to verify our results.展开更多
基金Supported by the China Postdoctoral Science Foundation(2014M552195)the State Key Laboratory Foundation of Subtropical Building,South China University of Technology(2013ZC13)the Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization,South China University of Technology(2013A061401005)
文摘Auto cascade refrigeration(ACR) cycle with phase separators is widely used in the cryogenic system. The composition of mixed refrigerant has a great effect on the performance of the system. Based on the assumption of infinite volume of phase separator, ACR system with one phase separator is simulated in this paper. The variation of refrigerant composition under different valves opening is obtained. A related experimental system is set up to verify the variation. The result shows that when the valve opening connected to the evaporator increases or the valve opening under the phase separator decreases, the low-boiling component concentration of the working mixture passing through the compressor and condenser increases, while the high-boiling component concentration decreases. Furthermore, the variations of condensation pressure and evaporation pressure under different valves opening are also observed. This paper is helpful to deepen the understanding of ACR system.
基金Foundation item： Supported by the National Natural Science Foundation of China（10801001） Supported by the Natural Science Foundation of Anhui Province（1208085MA13）
文摘By using cone expansion-compression theorem in this paper, we study boundary value problems for a coupled system of nonlinear third-order differential equation. Some sufficient conditions are obtained which guarantee the boundary value problems for a coupled system of nonlinear third-order differential equation has at least one positive solution. Some examples are given to verify our results.
