This reminds us of some of the basic characteristics of r4a refrigerant. The blue line on the left of the bubble represents the 100% saturated liquid line. Baehr, hans dieter, 1994, a international standard formulation for the thermodynamic properties of 1,1,1,2tetrafluoroethane. Technical r4a data sheet features and uses of r4a the refrigerant gas r4a is a hfc replacing r12 in new installations. The residual gas condenses in the heat exchanger 6. Calculation of dropper length for pumping refrigerants in flooded systems. Heat and mass transfer characteristics of absorption of. Pdf blend refrigerants combing hydrofluorocarbons and hydrocarbons are good substitutes to decrease the flammability of hydrocarbons. Appendix b log ph diagrams for refrigerants experts in brazed plate heat exchangers swep is a worldleading supplier of brazed plate heat exchangers for hvac and industrial applications. Tables for refrigerant of r4a in the domestic refrigerator. Myths and facts of hvac refrigerants daikin applied.
Flow boiling heat transfer of refrigerants r4a and r245fa in a horizontal microchannel article pdf available in experimental heat transfer 253. For thermodynamic properties the library uses new industrial formulation for r4a 1,1,1,2tetrafluoroethane, formulated in helmholtz energy. D the unit is designed to operates with r4a, the environment friendly refrigerant with zero odp ozone depletion potential d substantially reduced operating sound level, especially at partload operation. In this paper the heat and mass transfer characteristics of a horizontal tube absorber for the mixture r4admac in terms of experimentally gained heat and mass transfer coefficients are presented. R4a refrigerant,chemical refrigerant,china refrigerant. This dependency can be seen on the pressureenthalpy diagram. Indeed the vapour density increases with saturation temperature, resulting in a lower vapour velocity. This page shows log ph diagrams for the following refrigerants.
The log ph diagrams on this page can be retrieved from the coolpack program, which can be downloaded here. Some scientific and engineering data online german. Pdf hydrocarbon refrigerant mixtures as an alternative to r4a. The present work is focused on the thermal performance of a hydrocarbon blend refrigerant in a domestic refrigerator for retrofitting applications.
R4a is one of the most common refrigerants in the market today and can be bought at various locations either online or even at your local sams club. Pdf flow boiling heat transfer of refrigerants r4a and. Pdf cycle performance evaluation of various r4ahydrocarbon. R4a tetrafluoroethane tetrafluoroethane other names and brand names. The heat spreader under study has a foot print area of 15 x 15 mm2 and is.
The dupont oval logo, dupont, the miracles of science and suva. I managed to track down the values for r12 online by searching both formula and iupac name no luck with the others. For calculating heat transfer coefficients of the refrigerants two approaches have been considered. Pdf dynamics of bubble behavior in nucleate boiling of. Having drawn a logp,hdiagram, you can specify a refrigeration cycle and have the state points plotted on. A 4way valve before the cell ensured that the path length was the same for all analytes.
R4a has a global warming potential gwp of 0 with respect to carbon dioxide. A cyclic process can be represented very clearly in the ts. It has a great chemical and thermal stability, low toxicity and is nonflammable, besides having an excellent compatibility with most materials. Find the valve with the needle pierce and retract the stem all. Can anyone provide a source for the antoine values for determining saturation vapor pressure for r22 and r4a. In refrigerationheat pump engineering, the pressureenthalpy diagram fig. Table reading taken from the process of r4a refrigerant placed within the experimental setup. If youve overcharged your air conditioning system with r4a refrigerant, you neednt recharge the air conditioning system. Calculation of thermodynamic state variables of tetrafluorethane r4a. Hrnjak acrc cr45 january 2002 for additional information. Genetron is a registered trade name for allied signal corporation.
R4atables excel addin sample calculations in excel. Technical data sheet compressor model gl60pb 220240v. Improvement of r4a performances by addition of r290. The results showed a 9% increase in the performance with an r22 blend over. Enthalpy kjkg 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 pressure bar 0,50 0,60 0,70 0,80 0,90 1,00. There is currently serious consideration of replacing it with r744 carbon dioxide in refrigeration and heat pump applications. R4a is safe to use, as it is uninflammable, nonexplosive, nontoxic, nonirritant and noncorrosive. Refrigerant line sizes for remote systems revised 6.
Refrigerant line sizes for remote systems revised 61699 r12, r22, r502, r4a, and r404a commercial refrigeration page 1 of 6 in the selection of gas line sizes, the design engineer should be guided by the following criteria. The compression refrigeration cycle on the h, log pdiagram. P h diagram r4a pdf p h diagram r4a pdf p h diagram r4a pdf download. R4a is also known as tetrafluoroethane cf3ch2f from the family of hfc refrigerant. Experimental study on flow boiling of r4a and r410a in a. It is produced during respiration by most living organisms and is absorbed by plants. Our r4a refrigerant has no strange stench, and is for automobile refrigerating system. Since even a minimum quantity of r290 increases the performances of r l34a, an experimental test for the mixture r290r 4a atthe mass fractions 0. The mass transfer coefficient is strongly related to the subcooling of the solution. Page 1 unvented gas log heater or vented decorative appliance models. The heat transfer coefficient is mainly dependent on the solutions mass flow rate.
Additionally, this study reports the results of an experimental investigation of pool boiling heat transfer of r4a in a plain tube, a lowfin tube, and an enhanced thermoexcele tube as well. Since you have introduced excess refrigerant, you just need to reduce its pressure so that it meets the appropriate amount set forth by your cars. As all hfc refrigerants not damage the ozone layer. The refrigerating unit chosen for ourtests is a split unit for perishable goods delivery. The red fitting goes on the high side, the blue on the low side. A international standard formulation for the thermodynamic properties of 1,1,1,2tetrafluoroethane hfc4a for temperatures from 170 k to 455 k and pressures up to 70 mpa. There will ususally be three cans of r4a mixed with oil, a charging tube, and fittings to convert the old r12 to r4a style connectors. The gas mixtures of r22, r4a and air were generated using a gas mixing station with computerdriven massflow controllers mks, munich, germany. Hfc4a was developed to replace chlorofluorocarbon cfc refrigerants that contain chlorine, which damages the ozone layer. Mobile air conditioning systems are used across all transport modes including cars, buses, trucks and trains.
Ph18 for use with ph18r log sets, ph24 for use with ph24r or ph30r log sets warnings installation and operating 652035 instructions if the information in this manual is not ph logs cover page 2. With the discovery of the damaging effect of cfcs and hcfcs refrigerants to the ozone layer, the hfc family of refrigerant has been widely used as their replacement. Mistral refrigerant ph charts ph charts for r4a, r22, r404a, r407c, r410a, r717 ammonia and r744 carbon dioxide free download request. Table of contents contents ph gas logs thank you and congratulations on your purchase of an mhsc log set. Answer a states that r4a changes from a vapor to a liquid as it absorbs heat. R4a belongs to a group of chemicals called hydrofluorocarbons hfcs and is also known as hfc4a. Mistral refrigerant ph charts mistral associates r410a. How to recharge the r4 system when overcharged by peter grant. Assurance of adequate velocity thus insuring oil return capability. Before you consider buying a cylinder of r4a you need to ask yourself one question. Safety data sheet according to regulation ec no 19072006 and 4532010 dupont suva 4a refrigerant version 6. The record indicates subject imports of r4a from china exceed the.
In the present study, the thermal performance of a micro heat spreader based on flow boiling mechanism was evaluated. As the contribution of refrigerant gases to global warming has become an increasing issue, automotive oems have started to look for lower gwp replacements to r4a to become the long term refrigerant of choice. R4a pressure enthalpy chart the engineering mindset. Having drawn a log p,hdiagram, you can specify a refrigeration cycle and have the state points plotted on. Hydrofluorocarbons are used mainly as residential and automotive refrigerants. It is intended to be used for advanced technical applications. An experimental study of the thermal performance of r4a and. Hydrocarbon in r4a system charge and 12 charge of r4a.