Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 11 of 11 for “"Refrigerant distribution"”.
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Refrigerant distribution model development
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1995.
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Experimental and modeling study of lubricant effect on refrigerant distribution in microchannel evaporators
… used in industry for decades. But the problem of refrigerant maldistribution can significantly deteriorate the performance of heat exchanger (especially evaporator) and system. In real air conditioning systems especially automobile air conditioning systems where oil separator is less commonly …
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Performance measurement and visualization on the refrigerant distribution in the vertical manifold of the microchannel tube heat exchanger
This project studies the liquid refrigerant distribution of an intermediate vertical manifold in a multi-pass evaporator. A new test rig is designed and built to circulate R410A through the vertical microchannel manifold. Refrigerant is circulated into the manifold through the lower set of parallel …
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Experimentally validated models of refrigerant distribution in microchannel heat exchangers used to evaluate charge reduction of various working fluids
… and evaporators. Experiments with different refrigerants including R290, R717, R1234yf, and R134a are used to validate the models. The experimentally validated models are used to compare the charge of various refrigerants. The procedure for charge reduction analysis described in the thesis is …
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Flow distribution in brazed plate heat exchangers
… However, they suffer from the flow maldistribution among parallel plate channels. Especially when they are used as evaporators, the non-uniform distribution of two-phase refrigerant creates an unwanted superheated region, which has a lower heat transfer coefficient and a smaller …
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Refrigerant flow distribution in vertical headers of reversible microchannel heat exchangers
… pump mode, it functions as an evaporator and refrigerant maldistribution among parallel microchannel tubes creates unwanted superheated region, which lowers the heat transfer between refrigerant and air. This thesis presents the experimental and modeling study of refrigerant distribution in …
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Effect of conical distributors on evaporator and system performance
… study to experimentally examine effects of the distribution of refrigerant and air in the evaporator using a conical distributor on system COP and capacity. Several conditions at the distributor inlet are varied including quality, mass flux, and orientation in gravity and the resulting superheat …
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Oil flow from compressor valve to discharge tube
… compressor inevitably entrains some oil in the refrigerant vapor, which makes oil leave compressor and circulate in the system. For better heat transfer and refrigerant distribution, it is preferable to reduce the mass flow rate of oil in system circulation. Visualization of closing and opening …
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Two phase flow distribution in parallel flow heat exchangers -- experimentally verified model
Maldistribution of refrigerant is a problem in parallel microchannel heat exchangers that lowers their potential effectiveness, especially when controlled by superheat. This paper describes modeling and numerical simulation of two phase mass flow distribution in a microchannel evaporator, on the …
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A study on the characteristics of the flow inside a thermostatic expansion valve
… the spray and atomization process of the refrigerant. Most previous studies focused on the macro-features of the expansion valve, such as the refrigerant pressure drop through the valve, the response time of the valve to the change of superheat in the evaporator, or the relationship …
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Flash gas bypass - a way to improve distribution of adiabatic two-phase refrigerant flow in headers of microchannel evaporators
… method as a way to solve the existing problem of distribution of two phase adiabatic flow in headers of parallel flow evaporators, of typically microchannel design. Three main issues that will be explored in this thesis are: 1) separation of vapor-liquid refrigerant immediately after an expansion …