BACKGROUND

The embodiments herein relate to an evaporator for evaporating a single-phase liquid or two-phase fluid in a refrigerant system and more specifically to an insert for an evaporator header of the evaporator.

A distributor, e.g., a header, in refrigeration systems receives single-phase liquid or two-phase refrigerant flow and divides it equally to provide uniform feed to all passages of an evaporator. Each passage of an evaporator in a refrigeration system should have an equal fluid mass flow rate of refrigerant in order for the refrigeration system to effectively to use the evaporator. In addition, the header is used to reduce flow from a larger area within the header to a smaller area in the individual evaporator paths. In the case of removing heat from a large footprint area, the evaporator will be designed to have multiple parallel flow passages which allows the working fluid to be vaporized with reasonable pressure drop and temperature uniformity. In a parallel flow passage design, a flow distribution is a factor determining the overall evaporator performance. Under adverse gravity conditions of the type encountered in aerospace applications, characteristics of the flow dynamics into the evaporator passages from the header may result in reduced contact between the working fluid and the evaporator. This may reduce effectiveness of the system.

BRIEF SUMMARY

Disclosed is a header insert for an evaporator header outlet port of an evaporator header, including: a header insert body that extends along a body center axis between a body inlet end and a body outlet end, wherein the header insert body includes a center passage defined by a center passage surface located within the header insert body, the center passage surface extending from the body inlet end to the body outlet end along the body center axis, the center passage surface defining: a center passage inlet portion at the body inlet end; a center passage outlet portion at the body outlet end, the center passage outlet portion defining a body nozzle portion on the body center axis, the body nozzle portion having a convergent-divergent shape so that the body nozzle portion has a convergent segment, a divergent segment and a neck segment therebetween; and a conical tip member, fixed to the body outlet end and disposed at least partially within the divergent segment of the body nozzle portion so that a conical outlet passage is formed therebetween.

In addition to one or more of the above disclosed aspects or as an alternate, a divergent segment diameter is defined by the divergent segment, the divergent segment diameter sized so that the divergent segment defines an axial outer edge of the body outlet end.

In addition to one or more of the above disclosed aspects or as an alternate, a conical tip member base portion is defined by the conical tip member, the conical tip member base portion having a base portion diameter that is larger than a center passage diameter; and

the base portion diameter of the conical tip member is smaller than the divergent segment diameter.

In addition to one or more of the above disclosed aspects or as an alternate, the header insert further includes: one or more runners that connect the conical tip member to the body outlet end.

In addition to one or more of the above disclosed aspects or as an alternate, the header insert further includes a flange that extends radially outwardly from the header insert from a location that is axially between the body inlet end and the body outlet end; wherein the center passage outlet portion of the center passage surface is axially between the flange and the body outlet end.

Further disclosed is an evaporator assembly including a header insert having one or more of the above disclosed aspects and further including: the evaporator header that defines the evaporator header outlet port; an evaporator body that defines an evaporator passage in fluid communication with the evaporator header outlet port, and wherein the header insert is inserted into the evaporator header outlet port.

Further disclosed is a method of directing fluid through an evaporator assembly, including: directing a fluid into a center passage inlet portion of a center passage surface of a header insert from an evaporator header outlet port of an evaporator header; directing the fluid into a center passage outlet portion at a body outlet end of the center passage surface, the center passage outlet portion defining a body nozzle portion on a body center axis, the body nozzle portion having a convergent-divergent shape so that the body nozzle portion has a convergent segment, a divergent segment and a neck segment therebetween; directing the fluid into a conical outlet passage formed between the divergent segment of the body nozzle portion and a conical tip member fixed to the body outlet end of the header insert; and directing the fluid into an evaporator passage of an evaporator body from the conical outlet passage, wherein the fluid moves towards a sidewall of the evaporator passage and moves downstream along the evaporator passage.

Further disclosed is an internal insert for a header insert of an evaporator header outlet port, including: an internal insert tip portion; an internal insert base portion spaced along a body center axis from the internal insert tip portion; and an internal insert center body portion extending axially between the internal insert tip portion and the internal insert base portion, wherein: the internal insert tip portion converges away from the internal insert center body portion; the internal insert center body portion defines a first axial segment and a second axial segment extending away from one another, wherein the first axial segment extends to the internal insert tip portion and the second axial segment extends to the internal insert base portion; and a helical fluid passage surface, defining a continuous helical fluid passage, is formed into the internal insert center body portion.

In addition to one or more of the above disclosed aspects or as an alternate, the first axial segment defines a first axial segment diameter that is substantially constant and the second axial segment is formed to taper conically from the first axial segment to the internal insert base portion.

In addition to one or more of the above disclosed aspects or as an alternate, the internal insert further includes a ring segment defined by the internal insert base portion, the ring segment having a ring segment outer dimeter that is larger than the first axial segment diameter.

In addition to one or more of the above disclosed aspects or as an alternate, the internal insert further includes a plurality of ribs formed by the internal insert base portion, the plurality of ribs being circumferentially spaced apart from one another and extend radially inwardly to connect the ring segment to the internal insert, thereby defining a plurality of fluid inlet ports circumferentially spaced apart from one another, the plurality of fluid inlet ports being configured to guide fluid therethrough toward the helical fluid passage surface along the second axial segment of the internal insert center body portion.

In addition to one or more of the above disclosed aspects or as an alternate, a first radial through-hole is formed through the internal insert base portion, wherein the first radial through-hole is configured to receive a fixing pin for fixing the internal insert to the header insert.

Further disclosed is an internal insert having one or more of the above disclosed aspects in combination with a header insert, wherein the header insert includes: a header insert body that extends along the body center axis between a body inlet end and a body outlet end, wherein the header insert body includes a center passage surface defining a center passage that extends from the body inlet end to the body outlet end along the body center axis, the center passage surface defining: a center passage inlet portion at the body inlet end; a center passage outlet portion at the body outlet end, the center passage outlet portion defining a body nozzle portion on the body center axis, the body nozzle portion having a convergent-divergent shape so that the body nozzle portion has a convergent segment, a divergent segment and a neck segment therebetween; wherein the internal insert is configured for being disposed within the center passage, so that the internal insert tip portion is disposed at the convergent segment of the body nozzle portion and the internal insert base portion is at the center passage inlet portion of the center passage surface.

In addition to one or more of the above disclosed aspects or as an alternate, a radial outward step is formed at the body outlet end of the header insert, wherein the radial outward step is configured for seating against the internal insert base portion, thereby limiting axial motion of the internal insert within the header insert.

In addition to one or more of the above disclosed aspects or as an alternate, a second radial through-hole is formed by the body outlet end of the header insert, wherein when the internal insert is within the header insert, a first radial through-hole in the internal insert and the second radial through-hole are aligned with one another and configured for receiving a fixing pin.

In addition to one or more of the above disclosed aspects or as an alternate, a length defined by the internal insert, along the body center axis, is substantially the same as the center passage surface, between the body outlet end and the neck segment of the body nozzle portion.

In addition to one or more of the above disclosed aspects or as an alternate, the internal insert is configured for a clearance fit within the center passage.

In addition to one or more of the above disclosed aspects or as an alternate, the internal insert in combination with the header insert further includes: an evaporator header that defines the evaporator header outlet port; an evaporator body that defines an evaporator passage in fluid communication with the evaporator header outlet port, wherein the header insert is disposed in the evaporator header outlet port.

Further disclosed is a method of directing fluid through an evaporator assembly, including: directing a fluid along a center passage surface of a header insert from an evaporator header outlet port of an evaporator header; directing the fluid along an internal insert base portion of an internal insert disposed with a center passage; directing the fluid along a helical fluid passage surface formed into an internal insert center body portion of the internal insert; directing the fluid between an internal insert tip portion and a convergent segment of a center passage outlet portion of the center passage surface; directing the fluid through a neck segment of a body nozzle portion of the center passage surface; directing the fluid out of a divergent segment of the body nozzle portion of the center passage surface; and directing the fluid into an evaporator passage of an evaporator body from the center passage outlet portion of the center passage surface, wherein the fluid moves towards a sidewall of the evaporator passage and moves downstream along the evaporator passage.

In addition to one or more of the above disclosed aspects or as an alternate, directing the fluid through the internal insert base portion includes directing the fluid through a plurality of fluid inlet ports circumferentially spaced apart from one another, defined by a plurality of ribs that are circumferentially spaced apart from one another and that connect a ring segment of the internal insert base portion to the internal insert.

