Abstract: A cyclonic type lubricant separator with various features that reduces pressure losses, manages local gas velocities which may contribute to entrainment of liquid(s) (e.g. oil), maintains and/or improves oil separation (e.g. achieving lower oil circulation rates), reduces the size of the lubricant separator, and/or reduces or minimizes costs of production. Lubricant separators herein include a shell, a fluid inlet, a vapor outlet, a liquid outlet, and a discharge tube within the shell. Lubricant separators herein include multiple inlets that have openings such that the discharge tube is out of sight relative to the openings of the inlet, include openings along the length of the discharge tube, and/or include a flow director on the discharge tube, where the flow director includes a surface that extend away from the outer dimension of the discharge tube.

Abstract: Methods and systems to manage refrigerant levels in a chiller system are provided. An evaporator of the chiller system may be configured to have a spill over port allowing oil containing refrigerant to spill over through the spill over port. The spill over port may be positioned at a place that corresponds to a desired refrigerant level in the evaporator. The spill over refrigerant may be directed into a heat exchanger that is configured to substantially vaporize refrigerant of the spill over refrigerant to a slightly superheat temperature. A method of maintaining a proper refrigerant level in the evaporator may include regulating a refrigerant flow to the evaporator so that the vaporized refrigerant of the spill over refrigerant is maintained at the slightly superheat temperature.

Abstract: Methods and systems to manage refrigerant levels in a chiller system are provided. An evaporator of the chiller system may be configured to have a spill over port allowing oil containing refrigerant to spill over through the spill over port. The spill over port may be positioned at a place that corresponds to a desired refrigerant level in the evaporator. The spill over refrigerant may be directed into a heat exchanger that is configured to substantially vaporize refrigerant of the spill over refrigerant to a slightly superheat temperature. A method of maintaining a proper refrigerant level in the evaporator may include regulating a refrigerant flow to the evaporator so that the vaporized refrigerant of the spill over refrigerant is maintained at the slightly superheat temperature.

Abstract: Embodiments of a spill over tank for an evaporator of a HVAC system are described. The spill over tank may be configured to receive a refrigerant directed out of the evaporator. The spill over tank may be configured to have an outlet directing refrigerant in the spill over tank out of the spill over tank and flowing back to a compressor of the HVAC system. The spill over tank may be equipped with a refrigerant level sensor configured to measure a refrigerant level in the spill over tank. The measured refrigerant level in the spill over tank may be used to control and/or maintain a refrigerant level in the evaporator, and/or may be used to control a return refrigerant flow into the compressor of the HVAC system so as to manage an oil return to the compressor.

Abstract: A system for managing fluid level in an HVAC system includes a spill over tank for an evaporator of the HVAC system. The spill over tank may be configured to receive a refrigerant directed out of the evaporator. The spill over tank may be configured to include an outlet directing refrigerant into the spill over tank, out of the spill over tank and flowing back to a compressor of the HVAC system. The spill over tank may be equipped with a refrigerant level sensor measuring a refrigerant level in the spill over tank. The measured refrigerant level in the spill over tank may be used to control and/or maintain a refrigerant level in the evaporator, and/or to control a return refrigerant flow into the compressor of the HVAC system so as to manage an oil return to the compressor.

Abstract: Generally, management of refrigerant in an evaporator of an HVAC chiller is described. Methods, systems, and apparatuses to manage refrigerant in an evaporator can include one or combination of the following approaches: (1) by use a refrigerant displacement array to physically prevent refrigerant from residing where the array is positioned; (2) by control of the interstitial velocity of refrigerant flow within the volume of the shell of an evaporator; (3) by a phase biased distribution of the refrigerant mixture, so that a gaseous portion is uniformly distributed into the evaporator shell, while liquid refrigerant and oil is distributed into the evaporator shell at a designated area; and (4) by preventing or reducing the occurrence of foaming inside the evaporator through anti-foaming surfaces, such as by the use of refrigerant phobic and lubricant phobic material(s). Refrigerant management can in turn improve the thermal performance and overall efficiency of the evaporator.

Abstract: A photovoltaic device includes a substrate structure and at least one Se-containing layer, such as a CdSeTe layer. A process for manufacturing the photovoltaic device includes forming the CdSeTe layer over a substrate by at least one of sputtering, evaporation deposition, CVD, chemical bath deposition process, and vapor transport deposition process. The process can also include controlling a thickness range of the Se-containing layer.

Abstract: A photovoltaic device includes a substrate structure and at least one Se-containing layer, such as a CdSeTe layer. A process for manufacturing the photovoltaic device includes forming the CdSeTe layer over a substrate by at least one of sputtering, evaporation deposition, CVD, chemical bath deposition process, and vapor transport deposition process. The process can also include controlling a thickness range of the Se-containing layer.

Abstract: A heat exchange tube combines an external surface feature, for example having crushed fins and cavities, which can have very high boiling enhancement characteristics, with an internal surface feature, for example having high performing intersecting helices, e.g. “cross hatched” with an intersecting helix angle. The new tube can provide a high performing tube in a shell and tube evaporator that can be relatively smaller, more efficient, and that can use relatively lower refrigerant charge.

Abstract: A heat exchanger, for example a shell and tube flooded evaporator, has a refrigerant distributor that is positioned at an angle between the bottom of the shell and the sides of the shell, and includes an inlet that is welded to an inlet piping, where the inlet and inlet piping are in fluid communication with the refrigerant distributor, and are in a generally corresponding position orientation. Tubes of a tube bundles may extend proximate the bottom of the shell.

Abstract: Methods and systems to manage refrigerant levels in a chiller system are provided. An evaporator of the chiller system may be configured to have a spill over port allowing oil containing refrigerant to spill over through the spill over port. The spill over port may be positioned at a place that corresponds to a desired refrigerant level in the evaporator. The spill over refrigerant may be directed into a heat exchanger that is configured to substantially vaporize refrigerant of the spill over refrigerant to a slightly superheat temperature. A method of maintaining a proper refrigerant level in the evaporator may include regulating a refrigerant flow to the evaporator so that the vaporized refrigerant of the spill over refrigerant is maintained at the slightly superheat temperature.

Abstract: Embodiments of a water head for an evaporator in a HVAC system are provided The water head may have a fluid entrance and a fluid exit in a side-by-side arrangement on one end of the water head, and a distribution chamber and a collection chamber in a top-down arrangement on opposite side of the water head. The distribution chamber and the collection chamber are configured to be in fluid communication with inlets and outlets of a heat exchanging tube bundle respectively. The distribution chamber and the collection chamber can be configured to have continuously smooth surface contours to help reduce pressure drop and fluid separation, and promote advantageous distribution of the process fluid among heat exchanging tubes when a process fluid flows between the fluid entrance or the fluid exit, and the distribution chamber or the collection chamber.

Abstract: Generally, management of refrigerant in an evaporator of an HVAC chiller is described. Methods, systems, and apparatuses to manage refrigerant in an evaporator can include one or combination of the following approaches: (1) by use of a refrigerant displacement array to physically prevent refrigerant from residing where the array is positioned; (2) by control of the interstitial velocity of refrigerant flow within the volume of the shell of an evaporator; (3) by a phase biased distribution of the refrigerant mixture, so that a gaseous portion is uniformly distributed into the evaporator shell, while liquid refrigerant and oil is distributed into the evaporator shell at a designated area; and (4) by preventing or reducing the occurrence of foaming inside the evaporator through anti-foaming surfaces, such as by the use of refrigerant phobic and lubricant phobic material(s). Refrigerant management can in turn improve the thermal performance and overall efficiency of the evaporator.

Abstract: A refrigerant evaporator includes a shell having a refrigerant inlet and a refrigerant outlet, and a plurality of tubes disposed within the shell and carrying a process fluid. One embodiment includes at least a first plurality of the tubes are immersed in liquid refrigerant within the shell, and at least a second plurality of the tubes are partially immersed in liquid refrigerant and partially surrounded by gaseous refrigerant. The refrigerant evaporator also includes a baffle positioned adjacent the first plurality of tubes and immersed in the liquid refrigerant to displace the liquid refrigerant.

Abstract: Embodiments of a spill over tank for an evaporator of a HVAC system are described. The spill over tank may be configured to receive a refrigerant directed out of the evaporator. The spill over tank may be configured to have an outlet directing refrigerant in the spill over tank out of the spill over tank and flowing back to a compressor of the HVAC system. The spill over tank may be equipped with a refrigerant level sensor configured to measure a refrigerant level in the spill over tank. The measured refrigerant level in the spill over tank may be used to control and/or maintain a refrigerant level in the evaporator, and/or may be used to control a return refrigerant flow into the compressor of the HVAC system so as to manage an oil return to the compressor.

Abstract: A shell-and-tube evaporator of a refrigerant system includes a refrigerant inlet distributor that traps a pocket of gaseous refrigerant to displace liquid refrigerant underneath the evaporator's tube bundle, thereby reducing the total charge of refrigerant in the evaporator. In some embodiments, the distributor comprises four sections interconnected by a central refrigerant feed line, which properly apportions the refrigerant to the four sections.

Abstract: A shell-and-tube evaporator of a refrigerant system includes a refrigerant inlet distributor that traps a pocket of gaseous refrigerant to displace liquid refrigerant underneath the evaporator's tube bundle, thereby reducing the total charge of refrigerant in the evaporator. In some embodiments, the distributor comprises four sections interconnected by a central refrigerant feed line, which properly apportions the refrigerant to the four sections.

Abstract: According to one exemplary embodiment, a bipolar transistor comprises a base having a top surface. The bipolar transistor further comprises a base oxide layer situated on top surface of the base. The bipolar transistor further comprises a sacrificial post situated on base oxide layer. The bipolar transistor further comprises a conformal layer situated over the sacrificial post and top surface of the base, where the conformal layer has a density greater than a density of base oxide layer. The conformal layer may be, for example, HDPCVD oxide. According to this exemplary embodiment, the bipolar transistor further comprises a sacrificial planarizing layer situated over the conformal layer. The sacrificial planarizing layer has a first thickness in a first region between first and second link spacers and a second thickness in a second region outside of first and second link spacers, where the second thickness is generally greater than the first thickness.

Abstract: According to one exemplary embodiment, a bipolar transistor comprises a base having a top surface. The bipolar transistor further comprises a base oxide layer situated on top surface of the base. The bipolar transistor further comprises a sacrificial post situated on base oxide layer. The bipolar transistor further comprises a conformal layer situated over the sacrificial post and top surface of the base, where the conformal layer has a density greater than a density of base oxide layer. The conformal layer may be, for example, HDPCVD oxide. According to this exemplary embodiment, the bipolar transistor further comprises a sacrificial planarizing layer situated over the conformal layer. The sacrificial planarizing layer has a first thickness in a first region between first and second link spacers and a second thickness in a second region outside of first and second link spacers, where the second thickness is generally greater than the first thickness.

Abstract: According to one embodiment of the invention, a method for fabricating a MIM capacitor in a semiconductor die includes a step of depositing a first interconnect metal layer. The method further includes depositing a layer of silicon nitride on the first interconnect layer. The layer of silicon nitride is deposited in a deposition process using an ammonia-to-silane ratio of at least 12.5. The method further includes depositing a layer of MIM capacitor metal on the layer of silicon nitride. The method further includes etching the layer of MIM capacitor metal to form an upper electrode of the MIM capacitor. According to this exemplary embodiment, the method further includes etching the layer of silicon nitride to form a MIM capacitor dielectric segment and etching the first interconnect metal layer to form a lower electrode of the MIM capacitor. The MIM capacitor has a capacitance density of at least 2.0 fF/um2.