This paper presents the benefits in capacity and performance of a hybrid control of expansion valves for two 5-ton (17.6 kW) domestic heat pumps (HPs) based on experimental results. The hybrid control, as proposed by Kim et al. (2008a), employs a primary expansion valve that provides most of the pressure drop, while small secondary/balancing valves in the distributor lines to the circuits of th...

A capillary pumped loop (CPL) is a closed two-phase loop in which capillary forces developed in a wicked evaporator passively pump the working fluid over long distances to dissipate heat from electronic and power sources. Because it has no moving parts and requires minimal power to sustain operation, the CPL is considered an enabling technology for thermal management of spacecraft. While the st...

A planar, silicon mini capillary pumped loop (CPL) was designed, built, and tested using recent MEMS technology to provide integral cooling and temperature control for electronics. This design featured three silicon fusion bonded wafers incorporating an evaporator, condenser, liquid line and vapor line, all of which were dry plasma etched. Grooves were etched in the condenser and evaporator to ...

A numerical simulation of a liquid overfeed system working with pure refrigerants in steady state conditions has been performed. The global algorithm is based on the sequential resolution of the different elements of the system (compressor, evaporator, condenser, ... ). For each element, a simplified mathematical model based on global balances of mass, momentum and energy is used. For the evapo...

Mathematical model for a multiple effect evaporator system with condensate-, feedand productflash and steam splitting Ravindra Bhargava, Shabina Khanam*, Bikash Mohanty & Amiya K Ray Department of Chemical Engineering, Department of Paper Technology, Indian Institute of Technology Roorkee, Roorkee 247 667, India Department of Chemical Engineering, National Institute of Technology Rourkela, Rour...

The objectives of this study are to provide experimental data and a correlation that can be used in the optimal design of an evaporator under frost conditions. In the present study, we tested both a single stage and a two-stage evaporator with a variation of operating parameters and fin geometry under frost conditions. The effects of tube space and fin alignment on the heat transfer performance...

The rehabilitation ol' thc Xinavane sugar factory in Mozambique necessitated a redesign of the evaporator station. The particular arrangement at Xinavane proved to be extremely sensitive to changes i n operating parametcrs. Using this evaporator station as an example, the concept of design robustness (suitability under a range of operating conditions) is introduccd. A rigorous evaporator simula...