Experimental Study of Nucleate Boiling of Flammable, Environmentally Friendly Refrigerants

Abstract

This paper investigates the nucleate boiling process of dimethyl ether and selected hydrocarbons. The main goal of this study is to measure the heat transfer coefficients of RE170, R600a, and R601, and to compare them with R134a. The experiments were carried out for heat fluxes up to 70 kW/m 2 . Experimental results have shown a typical trend that the heat transfer coefficient of flammable refrigerants increases as the heat flux increases. Among the tested fluids, the highest values of heat transfer coefficient were obtained for RE170. Available correlations describing this coefficient showed a deviation of up to 93%, as compared to the data obtained. The new correlation was developed by regression analysis taking into account dimensionless variables affecting the boiling process.

Energy and Thermal Conductivity Assessment of Dimethyl-Ether and its Azeotropic Mixtures as Alternative Low Global Warming Potential Refrigerants in a Refrigeration System

“…RE170 is a liquefied gas which is nontoxic, odourless and colourless at room temperature. The ozone depletion potential of dimethyl-ether is equal to zero and its global warming potential is significantly very low (GWP = 1) which have made it a potential green refrigerant to the environment [48].…”

“…RE170 is produced from a variety of resources such as natural gas, biomass coal and methanol. Other components of R510A and R511A are hydrocarbons gasses (R600a and R290) and they are natural refrigerants generated as by-products in the production of natural gas [48]. The retail price or cost of refrigerants differs, with RE170 and its mixtures apt tending to cost less than conventional refrigerant (R134a).…”

“…The cost of R134a is in the range of 30 to 50 USD/kg while the cost of the hydrocarbon refrigerants (RE170, R600a and R290) is in the range of 0.3 to 6.0 USD/kg. R510A and R511A are binary blends of the hydrocarbon refrigerants [3], [48]. Therefore, the average cost of RE170, R510A and R511A is about 33.3 % less than the cost of R134a.…”

Theoretical Investigation of Performance of Vapor Compression Cooling Cycle for Dme, R125, R134a, R143a, R152a, and R32 Refrigerants and Their Mixtures

“…This study evaluated the thermodynamic performance of DME refrigerant and R125, R134a, R143a, R152a, and R32 refrigerants. Although DME is a highly flammable substance, it has recently found reuse as a working fluid in cooling and heating systems due to its minimal GWP and zero ODP [14,15]. Ozone Depletion Potential (ODP) and Global Warming Potential (GWP) values and ASHRAE Safety Groups of the selected refrigerants are shared in Table 1.…”

Hydrate Phase Equilibrium Data of Dimethyl Ether in the Presence of Tetrahydrofuran, Tetra-n-butylammonium Bromide, and Cyclopentane

“…In summary, a renewable hydrate guest with stable chemical properties, nontoxic, no ozone depletion potential (ODP), a low GWP, a low price, and a wide source is still the focus of future research. , It is found that dimethyl ether (DME, RE170) is widely studied as an environment-friendly (ODP = 0, GWP <3, which is only 1/500 of HFCs) and effective refrigerant, − which can be easily produced from renewable energy (biomass). , Moreover, it can significantly lower pressures under the same conditions than CO 2 with a low saturated vapor pressure, which is expected to reduce the operating pressure of the gas hydrate as a cold storage medium or refrigerant. However, there is still a lack of DME gas hydrate phase equilibrium data at low pressure and suitable temperature with these additives.…”