Application Research on Testing Efficiency of Main Drainage Pump in Coal Mine Using Thermodynamic Theories

Table 1

The test data through the thermodynamic method.

Number	Item	Unit	The adjustment point of flow
			1	2	3	4	5
()	The temperature at inlet	°C	18.561	18.563	18.563	18.560	18.561
()	The temperature at outlet	°C	18.835	18.911	18.955	19.205	19.426
()	The reading of vacuum gauge	MPa	0.034	0.036	0.037	0.039	0.040
()	The reading of pressure gauge	MPa	3.207	3.293	3.381	3.574	3.690
()	Voltage	V	6100	6085	6050	6090	6086
()	Current	A	67.40	65.92	62.69	60.70	56.60
()	The input power of electric machine	kW	579.79	565.02	538.87	525.36	487.28
()	The power of pump shaft	kW	545.12	533.55	515.01	507.88	490.47
()	The speed of pump shaft	r/min	1475	1479	1479	1470	1471
After conversion	The rate of flow	m^3/h	447.83	435.89	405.27	383.93	351.20
	The head of delivery	m	323.75	331.30	339.39	359.08	369.71
	The pump efficiency	%	72.47	73.66	70.17	68.34	67.98