Document 4Qrd93jkX3Oror1vJkkO5Z351

34 CHAPTER 3 1949 Guide d SSSSS S22" 22222 22222 so8 13.675 13.987 14.304. 14,628 14.958 3L> &S . i s i1 n wa o' l X ;: uo a Enthalpy Btu/Lb hm _ S < > 2 0ot 3 3 - <2^ auc. eas Ho . *az<. OS s < b U) O s 3 E n t h a l p y/ B tu lb dry a ir 1 [ c o Oh <x jO aJ bS > uD < .H Entropy Btu/^Lb) Sw 16.001 13.475 16.026 14.074 16.051 14.710 16.076 * 15.386 16.102 16.104 16.127 . 16.870 16.152 17.689 16.177 18.565 16.203 19.504 16.228 20.513 16.253 16.278 16.304 16.329 16.354 21:601 22.775 24.047 25.427 26.934 29.476 30.100 80.761 31.462 32.206 32.997 33.841* 34.742 35.707 36.741 37.854 39.053 40.351 41.756 43.288 44.959 46.790 48.805 51.036 53.516 56.291 59.416 62.058 67.007 71.681 77.142 42.087 42.328 42.569 42.810 43.051 43.292 43.534 43.775 44.016 44.267 44.498 44.740 44.981 45.222 45.463 45.704 45.946 46.187 46,428 46.670 46.911 47.153 47.394 47.636 47.877 48.119 601.1 627.1 654.7 684.1 715.2 643.2 669:4 697.3 726.9 758.3 0.07756 0.07794 0.07832 0.07870 0.07908 , .748.5 783.9 , 821.9 862.5 . 906.2 791.8 827.4 865.7 906.5 950.6 0.07946 0.07984 0.08021 0.08059 0.08096 953.2 1004 1059 1119 1184 1 997.7 1049 1104 1164 1229 I 0.08134 0.08171 0.08208 0.08245 0.08283 1.005 1.047 1.091 1.137 1.187 1.240 1.296 1.357 1.421 1.490 1.565 1.645 1.731 1.826 1.928 2.039 2.161 2.296 2.444 2.609 2.794 3.002 3.238 ` 3.507 3;8I7 4.179 1.083 1.125 1.169 1.216 1.266 1.319 1.376 1.437 1.502 1.671 1.646 1.727 1.813 1.907 2.011 2.122 2.245 2.380 2.528 2.694 2.879 3.087 . 3.324 3.593 3.9044.266 143.02 144.02 145.02 146.03 147.03 148.03 149.03 150.04 151.04 152.04 153.05 164.05 155.05 156.06 157.06 168.07 159.07 160.07 161.08 162.08 163.09 164.09 165.10 166.10 167.11 168.11 0.2553 0.2568 0.2584 0.2600 0.2616 0.2631 0.2647 0.2662 0.2678 0.2693 15.294 16.636 15.985 16.340 1 16.702 0.2709 0.2724 0.2740 0.2755 0.2771 17.071 17.446 17.828 18.217 18.614 16.379 10.405 16.430 16.455 16.480 28.580 30.385 32.375 34.581 37.036 1255 1332 1418 1513 1619 1301 1378 1464 1559 1666 0.08320 0.08357 0.08394 0.08431 0.08468 0.2786 0.2802 0.2817 0.2833 0.2848 19.017 19.427 19.845 20.271 20.704 16.506 16.531 16.556 16.581 16.607 16.632 39.785 42.885 46.402 50.426 55.074 60.510 1737 1871 2022 2195 2395 2629 . 1784 1918 2069 2243 2443 2677 0.08505 0.08542 0.08579 0.08616 0.08653 0.08689 0.2864 0.2879 0.2895 0.2910 0.2925 0.2040 21.145 21.694 22.050 22.514 22.987 23.468 if 1 j;i-1 tj 0.5292 0.5529 0.5760 0.0016 - 0.6288 0.0578 0.6887 0.7218 0.7572 0.7953 0.8363 0.8805 0.9283 0.9802 1.037 1.099 1.166 1.241 1.324 1.416 1.519 ' 1.635 1.767 1.917 2.091 2.295 H u m id ity R a tio W* 5 fife gssss ssgsg sssss ssgsgg. J Complieedd by John JAV.. Goff anid1 S. CGratchht.. Thermodynamics 35 In Table 1 there are 15 columns of figures, each column being headed by a suitable symbol. In the following sub-paragraphs are given brief explanations of the data in Table 1 under the appropriate column headings. ((F) -- Fahrenheit temperature defined in terms of absolute temperature T by the relation, T = t + 459.69 (1) This particular Fahrenheit scale differs slightly from that derived from the Inter national Centigrade Scale ((C) by the definition, ((F) = 1.8i(C) + 32 (2) However, the nmyimiim difference between the two Fahrenheit scales appears not to exceed 0.01 Fahrenheit deg in the range 32 to 212 F. W. = humidity ratio at saturation. By humidity ratio is meant the ratio, by weight, of water vapor to dry air, pounds of water vapor per pound of dry air. By saturation is meant the point where coexistence of the vapor phase (moist air) with a condensed phase (liquid or solid) is possible at the given temperature and pressure (standard atmospheric pressure in the case of Table 1). At given values of tempera ture and pressure the humidity ratio W can have any value from zero to W,. . = specific volume of dry air, cubic feet per pound. ,,=.-- the difference between the volume of moist air at saturation, per pound of dry air, and the specific volume of the dry air itself, cubic feet per pound of dry air. v. = volume of moist air at saturation per pound of dry air, cubic feet per pound of dry air. : specific enthalpy of dry air, Btu per pound. It will be noticed that the spe cific enthalpy of dry air has been assigned the value zero at 0 F, standard atmospheric pressure. The energy unit Btu is related to the foot-pound, though not exactly, by definition, as follows: 1 Btu = 778.18 ft-lb. Ass = A. -- A., the difference between the enthalpy of moist air at saturation, per pound of dry air, and the specific enthalpy of the dry air itself, Btu per pound of dry air. Aa = enthalpy of moist air at saturation per pound of dry air, Btu per pound of dry air. s. = specific entropy of dry air, Btu per (pound) (F). It will be noticed that the specific entropy of dry air has been assigned the value zero at 0 F and standard atmos pheric pressure. *ss = 8s -- *s, the difference between the entropy of moist air at saturation, per pound of dry air, and the specific entropy of the dry air itself, Btu per (pound of dry air) (F). s. = entropy of moist air at saturation per pound of dry air, Btu per (pound of dry air) (F). A, = specific enthalpy of condensed water (liquid or solid) at standard atmospheric pressure, Btu per pound of water. The specific enthalpy of liquid water has been assigned the value zero at 32 F, saturation pressure. It will be noticed that, under this assignment, the specific enthalpy of liquid water at 32 F, standard atmospheric pressure, assumes the value 0.04 Btu/lb,. s = specific entropy of condensed water (liquid or solid) at standard atmospheric pressure, Btu per (pound of water) (F). The specific entropy of liquid water has been assigned the value zero at 32 F, saturation pressure. It will be noticed that, under tins assignment, the specific entropy of liquid water at 32 F, standard atmospheric pressure, is also zero, though not exactly. y'