保温灯变功率供暖对哺乳仔猪环境调控及节能效果.

Temperature in the creep area for piglets will decrease from birth to weaning. To reduce the consumption of electricity and meet the temperature requirement of piglets from birth to weaning, an experiment of variable power heating system of heat lamp compared with constant power heating system of heat lamp was conducted in a scaled pig farm in Northern China. Two units of farrowing room (one unit with 23 farrowing sows and 25 heat lamps of 250 W) in the pig farm were chosen for this study, except for heat lamps, hot water floor heating was provided for piglets. An automatic control system which was composed of ATS (air temperature sensor) and SCM (single chip microcomputer with PID (proportional, integral and derivative) control) and SCR (silicon controlled rectifiers) was used in the test unit and constant power heating system was used in the control unit. The temperature automatic control system can bear 10 000 W. In the test unit, temperature of 30.0 was set from piglets birth to the age of 7 °C days, and then reduce temperature by 2.0 °C every week till 21 days after birth. In the control unit, heat lamp was with constant power to heat piglets creep areas. Electricity consumption used in the test unit and control unit was recorded by two ammeters, respectively. Behaviors and temperatures in creep area of piglets were recorded and analyzed. Piglets performance was also recorded and analyzed. It was shown that during the first week after birth, both of the heat lamps in the test unit and in the control unit maintain full power operation, the average temperature right below the heat lamp (0.3 m high from the floor) was 27.4 °C; during the second week, the average temperature right below the heat lamp for the test unit and the control unit were 27.2 and 27.5 °C, respectively; during the third week, the average temperature right below the heat lamp for the test unit and control unit were 26.8 and 27.4 °C, respectively. Floor temperature right below the test unit and control unit were 29.5-31.0 and 31.0-30.6 °C, respectively. In brief, from birth to 21 days, floor temperature right below the heat lamp, side below the lamp and the slatted floor were 29.5-31.0, 28.9-29.5 and 22.9-23.0 °C, respectively. Lying rates in different areas of right below the heat lamp, side below the lamp and the slatted floor were 40.7%-66.5%, 14.4%-33.4% and 0.9%-8.7%, respectively. Rates of survival of piglets (28 days weaning) in the test unit and control unit were 95.8% and 93.8%, respectively. Average daily gain of piglets (28 days weaning) in the test unit and control unit were 0.198 and 0.193 kg/(head·d), respectively. Using this kind of variable power heating system, the farrowing room can save 1.8 kW·h per lamp per day from 8 days to 14 days after piglets birth, and 2.7 kW·h per lamp per day from 15 days to 21 days after piglets birth. The energy consumption can be saved by 25.4% each batch of production based on 21 days weaning. On condition of electricity price of 0.5215 yuan/(kW·h), 25 heat lamps with 250 W in one farrowing unit and investment of one set of equipment of temperature automatic control with 2 980 yuan, payback period will be 2 a. The temperature automatic control system of heat lamp can not only save energy but also can improve piglets performance. [ABSTRACT FROM AUTHOR]