The pressure enthalpy diagram is analysed by selecting a particular region of the mollier diagram of refrigerant r4a as shown in figure 1. In order to properly understand this diagram, it is best to go through the vapor compression. Practical application of refrigerants r600a and r290 in small. Everything that occurs in the saturation zone is a latent change. In the mollier diagram the mj e16vx s1 pdf absolute humidity content in the air is shown along the xaxis. Tables 1 presents the test conditions applied for r22 and r1270.
Lines a, b, c, and d represent the status of the refrigerant as it travels through a sample system. Figure 1g applies to hfc 4a, the subject of this text. It has been in use since the early 1990s and now, in 2019, we are beginning to see its popularity wane with the rise of the new hfo refrigerant known as r1234yf. Thermodynamic properties of duponttm freonr 12 r12. R4a has a global warming potential gwp 0 times the value. Enthalpy is listed along the bottom and top of the diagram. Mollier diagram pro is an easy to use mollier diagram with which you can make calculations of air treatment processes. Hfc 4a pressure enthalpy diagram engineering units. R 4a is the most common refrigerant found in automobiles today. Case1 the basics of refrigeration cycle ph diagram analysis. Pressureenthalpy diagram for r4a refrigerant ohio university. Jul 07, 2019 pressure enthalpy diagram this diagram describes the relationship of pressure and enthalpy of a select refrigerant. How to read p h chart explained with numerical youtube. Pressureenthalpy chart, r4a 1,1,1,2tetrafluoroethane enthalpy kjkg pressure bar pressure mpa produced by tecquipments vdas system.
Answer to automobiles use refrigerant r 4a in their air conditioning systems. The blue line on the left of the bubble represents the 100% saturated liquid line. It is important to note that in the mix region, the pressure. Pressure enthalpy diagram this diagram describes the relationship of pressure and enthalpy of a select refrigerant. Refrigerants r407c and r407a properties, uses, storage. H 2 o mollier diagram pressure enthalpy diagram based on the scientific iapws95 formulation mollier chart in metric units excel file 342 kb. Sep 28, 2004 the pressure enthalpy ph diagram is a useful tool for refrigeration engineers and designers. The most common type of pressure enthalpy diagram is shown in figures 1a through 1h. Table a5e saturated waterpressure table table a6e superheated water table a7e compressed liquid water table a8e saturated icewater vapor figure a9e ts diagram for water figure a10emollier diagram for water table a11esaturated refrigerant4a temperature table table a12esaturated refrigerant4apressure table. Please provide feedback on this module by selecting like or dislike. R4a pressure gauge chart this chart details how ambient temperature correlates with the system refrigerant charge pressure, and how it affects high and low side psi readings. The vertical axis shows the logarithmic pressure and the horizontal axis shows the speci. Subcritical cptes below the critical pressure the most energetically interesting region is under the dome where large excursions in h exist for isothermal processes.
This article is written by my buddy and canadian supertech tim tanguay. The green highlighted thumb shape is the saturation zone. Various refrigerant states identified on a pressure enthalpy chart. The simplest and most straight forward use case is the generation of plots with default isolines and spacing. The pressure enthalpy diagrams for freon 407c are shown in figures 1 and 2. Pdf plotting of ph and ts diagrams of fluoropropylenes. Reading data of the diagram ph there is still many other information. The ph diagram is a graphical representation of the refrigerant as it travels through the refrigeration system.
The pressure enthalpy diagram or ph diagram is a tool that all hvac and refrigeration engineers should be able to use proficiently. This information is based on values calculated using the nist refprop database mclinden, m. That being said, there are still millions of cars on the road that. They show all five properties for a specific refrigerant in presentday use. So pressure enthalpy diagrams for some concentrations of the binary mixture r123 r4a were obtained by use of the pr equation of state with the identified interaction parameter. Pressure is listed along the right and left borders in psia. Applications solstice n r 450a is an excellent medium pressure, low gwp. Table a12esaturated refrigerant 4a pressure table table aesuperheated refrigerant 4a figure a14eph diagram for refrigerant 4a. How to read refrigerant property diagrams r4a youtube. Mollier diagram pro is the best program i have on my laptop. In the case of r22, the critical temperature is 205. First, an explanation of how the diagram is built up is given, and then its use is describ ed. It is recommended that the engineer get a copy of the ph diagram for r4a and the other common refrigerants.
Calculation of thermodynamic state variables of tetrafluorethan r4a in saturation state, boiling curve lower limit for calculation. Thermodynamic properties booklets are also available for freon 407c and freon 407a in both english and metric units. Scroll down to find download buttons for pressure enthalpy charts in either metric or imperial units. Figure 3 enthalpy entropy hs mollier diagram for watersteam. Pressureenthalpy chart, r4a 1,1,1,2tetrafluoroethane. The twophase dome and lines of constant pressure are shown.
It can demonstrate how an excessive suction line pressure drop and excessive return vapor temperature can cause an increase in the discharge temperature. Jan 30, 2014 learn various states of a refrigerant by drawing a pressure enthalpy chart. Pressure enthalpy diagram melting line40 o 40 c2 02 0 t 0 o c 0 0 20 40 40 60 60 80 80 100 100 120 120 140 140 160 160 180 180 200 200 220 220. R4a pressure enthalpy chart the engineering mindset. The pressure enthalpy diagram log ph diagram is a very useful tool for refrigerant technicians. For example, if a compressor operates at a suction pressure of refer to figure 8. R22 pressure enthalpy chart the engineering mindset. Figures 2 through 7 use the hfc 4a pressure enthalpy diagram to show the information available from such diagrams when their. R4a high and low side ac system temperature pressure chart. In connection with this the normal boiling point, is close to r22 also. Refrigeration pressure enthalpy chart refrigerant states youtube. It is important to note that in the mix region, the pressure and temperature are dependent variables. Po box, the heath, runcorn, cheshire, wa7 4qx tele. From pressure enthalpy diagram at corresponding pressure and temperatures.
For refrigeration, the diagram is reduced to the relevant regions of liquid and gaseous as well as their mixed form. Table a12 saturated refrigerant 4a pressure table table a superheated refrigerant 4a figure a14 ph diagram for refrigerant 4a figure a15 nelsonobert generalized compressibility chart. Jan 30, 2014 learn refrigerant flow in a vapor compression system using a schematic of various components and a pressure enthalpy diagram. There is currently serious consideration of replacing it with r744 carbon dioxide in refrigeration and heat pump applications. Figure 2 an enthalpy versus temperature diagram for r4a 5. This diagram describes the relationship of pressure and enthalpy of a select refrigerant. It can be used for recharging refrigerant, or to diagnose an ac system based on pressure readings from your gauges. The bubble to the left is the portion of the diagram where the refrigerant is in the saturated condition. Pressureenthalpy diagram sspecific entropy, kjkgk ttemperature. Pressureenthalpy diagram for water ohio university.
In general, a log ph diagram shows the aggregate state of a substance, depending on pressure and heat. Pressure enthalpy diagram melting line40 o 40 c2 02 0 t 0 o c 0 0 20 40 40 60 60 80 80 100 100 120 120 140 140 160 160 180 180 200 200 220 220 240 o c 240 260 280 e n t r o p y 6 2. This guide will take you through the pressure enthalpy diagram. In addition, tabular data in the superheated vapor region are given for r 4a to assist stu. This case is also to evaluate various cycles such as with penalties, economizing for a. Here is a brief example to demonstrate how to create a pressure enthalpy \\log p,h\ plot for propane r290 with automatic isoline spacing. I use it for optimization of installations and to accurately determine whether heat wheels work correctly rene hemme, hemmeonderhoudsadvies.
Find the properties at point 4, the pressure drop across the expansion device, the quality of the refrigerant and properties at point 1. Figure a29 generalized enthalpy departure chart figure a30 generalized entropy departure chart figure a31 psychrometric chart at 1 atm total pressure table a32 onedimensional isentropic compressibleflow functions for an ideal gas with k 1. R4a has a global warming potential gwp of 0 with respect to carbon dioxide. The environmental alternative to traditional refrigerants. Download a pdf copy of the pressure enthalpy chart for both metric and imperial units. Forane 4a, r 4a, pressure temperature chart, pt chart, hvac, refrigeration, air conditioning, refrigerant gas created date. Even if the properties of r1234zez could be utilised in specific applications like high temp heat pumps, r1234zee will show operating conditions and applied costs much more in line with r 4a according to system and compressor sizes. Additional physical property data may be found in other chemours publications.
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