Question

2 A cooling loop for hydraulic fuid (MIL-M-5606) consists of A heat exchanger whose carve of pressare drop versus flow rate is gives in Fig. P4-2(4). 150 ft of 3-in. schedule 80 pipe +4 standard elbows abead of the exchanger 150 ft of 3-in. schedule 80 pipe + 4 standard elbows aftor the exchanger 1 gate valve The fluid enters the exchanger at 200 P and leaves at 80"F. The loop leaves and enters the machine at the same level. The outlet reservoir has a sharp entrance, and an inlet reservoir is present. The system has a Goalds 1jx3-8 pump [cbaracteristics given in Pig P4-20) that runs at 1,750 rpm. The pump has a 7-in. rotor. For this sysem (a) Plot H versus Q for the loop with the gate valve fully open. (b) Plot H versus Q for the loop with the gate valve one-quarter open 25 16 10 0 2o 460 100 120 Oill flow, ginin FIGURE P4-2A Heat-exchanger pressare ai (e) From the manufacturer's data, plot H versus Q for the pump (d) Find the operating point for part (a) (e) Find the power required for part (d) (0 Find the operating point for part (b). (g) Find the power required for part ( STX AB 1750 RPM

Answer 1

O) flot l vevsus &for the loop uaith gate vvs ^olly oppn o dvive fhe heat ex is constant then. density fluid. 4 GCcelet tH head devoloped flow γ9te of fluid Thevefore,let PP YCCfg ng U19% hyper bolg OR ke C,

th. Thus Fully Open Gate Qusytey opengate

Pot valuesn 2ution Also C-0.06 Propevt ies given loid-1 H: 0.1332 0.16

Now subst it ot in different value : g Q to find -H, as shown in table below AAIn I.20 0. 296 2.400. 33) 4,S0. 269. ( 0.3 0.353 0. 331 . 0.296 40 MI

(g) Operating Point for omHgI Dismeter of pump rotor "D- ½ in. Romp cpeed let os coneide p'ipe tenth of loo ft Thus hesd loes at inet and outle s rlon1 lSo Total hesd to be genevsfred by nurp fi 了2.2 H 101.sf Covect operatin pont anchssctevictice cove is t and N 1a5o yp