scholarly journals Refractory Biliary Catheter Leak Corrected by a Hybrid Closed Loop Catheter-Pump System

2021 ◽  
Vol 2021 ◽  
pp. 1-4
Author(s):  
Ravi Murthy ◽  
Varun Rachakonda ◽  
Juri Bassuner

The development of inoperable biliary obstruction in patients with liver, biliary, and pancreatic neoplasia is commonplace particularly in the advanced stages of these diseases. Under these circumstances, restoring bile flow to the gut is paramount in reestablishing homeostasis. Hitherto, this has been achieved by utilizing passive, gravity-dependent bilioenteric conduits with the use of perforated plastic catheters or metallic stents inserted either in a percutaneous transhepatic fashion or via endoscopic techniques. A frequent untoward event of biliary decompression utilizing percutaneous transhepatic catheters (PTC) is the development of pain, cholangitis, hyperbilirubinemia, or pericatheter bile leak due to the suboptimal normalization of bile flow. In some instances, the etiology of PTC malfunction can be correctly ascribed to catheter malposition and/or catheter lumen obstruction; however, in the majority, it remains radiographically occult on transcatheter cholangiography—the “gold standard.” Regardless of findings, the management remains fluoroscopic repositioning or exchanges for larger diameter catheters to attempt to seal the pericatheter potential space and prevent bile seepage. Unfortunately, these maneuvers are met with limited and unpredictable levels of success. We present the successful management of an instance of recalcitrant external pericatheter bile leak mitigated by employing a hybrid closed loop biliary catheter-pump system by employing an assortment of FDA approved off-the-shelf medical devices.

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4294
Author(s):  
Gaurav Shrestha ◽  
Mayumi Yoshioka ◽  
Hikari Fujii ◽  
Youhei Uchida

Evaluation of appropriate areas to introduce a closed-loop ground-source heat pump (GSHP) system in the case of a standard detached residence was conducted in Akita Plain, Japan. Depth of borehole heat exchanger (BHE) required to use a GSHP system was taken as the suitability index, which is simpler for the general public to understand and to promote the system. Heating and cooling loads of the standard size detached residence were calculated based on the 2013 Energy Conservation Standard. To estimate BHE depths and estimate a suitable area, identical 3D BHE models were constructed at 30 points in the plain. Required BHE depths were determined by performing heat exchange simulations at each location using the calculated loads and heat exchange rates. A suitability map showing distribution of the required BHE depths was prepared. BHE depths were shorter in the north-western area compared to the other parts, implying that the coastal lowlands in this area are more suitable for closed-loop system in the standard detached residences in terms of heat exchange performance as well as the cost reduction. Thickly distributed Quaternary System with higher thermal conductivity is contributing to shorter BHE depths. The suitability map is effective to adopt potential areas for the system installation in the standard detached Japanese residences.


Energy ◽  
2011 ◽  
Vol 36 (5) ◽  
pp. 3224-3232 ◽  
Author(s):  
Kadir Bakirci ◽  
Omer Ozyurt ◽  
Kemal Comakli ◽  
Omer Comakli

Author(s):  
Jung Chan Park ◽  
Kil Young Kim ◽  
Jinhee Jeong ◽  
Seung Jin Song

A typical turbo heat pump system consists of a centrifugal compressor, expansion valve, and two heat exchangers or plenums — a condenser and evaporator. Compared to a gas turbine, a turbo heat pump introduces additional complexities because it is a two-phase, closed-loop system with heat exchange using a real gas/liquid (refrigerant) as working fluid. For such systems, a new linear stability model has been developed by applying a linearized small perturbation method to the nonlinear turbo heat pump surge model. When the new linear model is applied to a compressor in an open loop system (e.g. turbocharger), results identical to those of Greitzer’s model are obtained. When applied to an operating turbo heat pump, the new model accurately predicts the surge onset point. Finally, results from a parametric study on the influence of the B parameter on surge onset are presented. Thus, the new model can be applied to predict stability of various compression systems — either open or closed-loop systems running single or two-phase working fluids with or without heat exchange.


Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 553 ◽  
Author(s):  
Muhammad Kashif Shahzad ◽  
Mirza Abdullah Rehan ◽  
Muzaffar Ali ◽  
Azeem Mustafa ◽  
Zafar Abbas ◽  
...  

This paper presents an experimental evaluation of a closed loop lake water heat pump (LWHPs) system based on the slinky coiled configuration. Initially, a mathematical model is developed in the Engineering Equation Solver (EES) for the heat pump system and the submerged coils in a lake. System performance is determined for the submerged slinky copper coils under the various operating conditions. Afterwards, parametric analysis is performed considering different influencing parameters, such as the lake water temperature, ambient temperature, and mass flow rate of the circulating fluid at constant lake depth of 4 ft. The experimental setup is developed for 3.51 kW cooling capacity after cooling load calculation for a small room. In the current study, slinky copper coils are used to exchange heat with lake water. The experimental setup is installed in Taxila, Pakistan, and the system’s performance is analyzed during selected days. After experimentation based on hourly and daily operation characteristics, it is observed that the lake water temperature has significant influence on the heat transfer rate between slinky coil and lake water. While the lake water temperature in summer decreases and increases in winter with the depth. The resulted daily average coefficient of performance (COP) of the system is within the range of 3.24–3.46 during the selected days of cooling season. Based on these results, it can be concluded that the LWHP systems can be considered a viable solution for Pakistan having a well-established canal system.


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