A heat exchanger that arranges flat tubes horizontally has a vertical header that distributes the refrigerant to each tube. When the heat exchanger works as an evaporator, differences in flow conditions at each branch...A heat exchanger that arranges flat tubes horizontally has a vertical header that distributes the refrigerant to each tube. When the heat exchanger works as an evaporator, differences in flow conditions at each branch, such as the ratio and distribution of vapor and liquid, due to the differences in densities and momentums of vapor and liquid in the two-phase flow make equal distribution difficult. This paper describes the distribution characteristics of a four-branch header that has a rectangular cross-section without the internal protrusion of flat tubes in the case of the inflow of the refrigerant R32 from the bottom of the header by using an equipment that can estimate the distribution ratio of the liquid and vapor phase to each branch. This paper also discusses the distribution characteristics on the basis of the flow visualization in the header. The flow visualization shows that a liquid level that contains vapor phase exists in the header and affects the distribution greatly.展开更多
The first part of the paper shows that in American and European academia, the field of intellectual history has continued to neglect the world outside of the West. The reasons for this Eurocentric bias are related to ...The first part of the paper shows that in American and European academia, the field of intellectual history has continued to neglect the world outside of the West. The reasons for this Eurocentric bias are related to lasting hierarchies in the global landscape of historiography. To put it bluntly, Western scholars can afford to ignore historical approaches from other parts of the world, while the opposite is not the case. Whereas fields like subaltern studies have pointed at such problems, these hierarchies （and their historical roots ） have thus far hardly been considered in the debate about the future of intellectual history. In the second part, the paper outlines some important research agendas for the field of global intellectual history. For example, it argues that the transnational spread（ and local adaptation） of Eurocentric ideas since the 19th century remains insufficiently understood. The same is true for the changing facets of international hierarchies of knowledge, which have continued to influence historical scholarship around the world up until the present day.展开更多
文摘A heat exchanger that arranges flat tubes horizontally has a vertical header that distributes the refrigerant to each tube. When the heat exchanger works as an evaporator, differences in flow conditions at each branch, such as the ratio and distribution of vapor and liquid, due to the differences in densities and momentums of vapor and liquid in the two-phase flow make equal distribution difficult. This paper describes the distribution characteristics of a four-branch header that has a rectangular cross-section without the internal protrusion of flat tubes in the case of the inflow of the refrigerant R32 from the bottom of the header by using an equipment that can estimate the distribution ratio of the liquid and vapor phase to each branch. This paper also discusses the distribution characteristics on the basis of the flow visualization in the header. The flow visualization shows that a liquid level that contains vapor phase exists in the header and affects the distribution greatly.
文摘The first part of the paper shows that in American and European academia, the field of intellectual history has continued to neglect the world outside of the West. The reasons for this Eurocentric bias are related to lasting hierarchies in the global landscape of historiography. To put it bluntly, Western scholars can afford to ignore historical approaches from other parts of the world, while the opposite is not the case. Whereas fields like subaltern studies have pointed at such problems, these hierarchies （and their historical roots ） have thus far hardly been considered in the debate about the future of intellectual history. In the second part, the paper outlines some important research agendas for the field of global intellectual history. For example, it argues that the transnational spread（ and local adaptation） of Eurocentric ideas since the 19th century remains insufficiently understood. The same is true for the changing facets of international hierarchies of knowledge, which have continued to influence historical scholarship around the world up until the present day.
