农业工程学报
農業工程學報
농업공정학보
2013年
17期
169-175
,共7页
张世羊%李谷%陶玲%李晓莉
張世羊%李穀%陶玲%李曉莉
장세양%리곡%도령%리효리
水产养殖%氧%农业机械%精养池塘%增氧方式%增氧能力%节能%溶氧
水產養殖%氧%農業機械%精養池塘%增氧方式%增氧能力%節能%溶氧
수산양식%양%농업궤계%정양지당%증양방식%증양능력%절능%용양
aquaculture%oxygen%agricultural machinery%intensive culture pond%aeration approach%aeration capacity%energy-saving%dissolved oxygen
当前对于在精养池塘中如何配制和合理使用不同机械增氧方式缺乏系统的比较研究。该文为了探讨高温季节晴好天气不同机械增氧方式对池塘溶氧全天调控的影响,试验设计如下:于夏天高温季节集中对精养池塘应用3种不同增氧方式,在晴好天气的白天和夜间进行增氧效果试验。结果发现:无论增氧机开启与否,池塘的溶氧都存在明显的昼夜起伏,且在午后出现峰值。增氧机的开启增强了上下水层交换,削减了氧差,减少了上层溶氧的逸出损失,提升了下层水体的低溶氧水平。池塘上层溶氧起伏程度大于下层,下层溶氧变化滞后于上层(下层溶氧出现峰值落后于上层约2~5 h),且这种滞后性为增氧机运行所削弱。夜间增氧能向池塘补充溶氧,但仍不足以弥补鱼类和浮游生物的代谢、微生物的生长及有机物的氧化分解造成的溶氧损耗。单从机械增氧能力来看,叶轮式>微孔式>耕水机。综合分析节能和增氧效果,在精养池塘养殖环境下,白天开机增氧选择耕水机较为合适,而夜间应急增氧选择叶轮式更可取。试验通过对不同机械增氧方式增氧效果和能耗的系统比较,为合理选择和使用增氧方式提供了一定的参考价值。
噹前對于在精養池塘中如何配製和閤理使用不同機械增氧方式缺乏繫統的比較研究。該文為瞭探討高溫季節晴好天氣不同機械增氧方式對池塘溶氧全天調控的影響,試驗設計如下:于夏天高溫季節集中對精養池塘應用3種不同增氧方式,在晴好天氣的白天和夜間進行增氧效果試驗。結果髮現:無論增氧機開啟與否,池塘的溶氧都存在明顯的晝夜起伏,且在午後齣現峰值。增氧機的開啟增彊瞭上下水層交換,削減瞭氧差,減少瞭上層溶氧的逸齣損失,提升瞭下層水體的低溶氧水平。池塘上層溶氧起伏程度大于下層,下層溶氧變化滯後于上層(下層溶氧齣現峰值落後于上層約2~5 h),且這種滯後性為增氧機運行所削弱。夜間增氧能嚮池塘補充溶氧,但仍不足以瀰補魚類和浮遊生物的代謝、微生物的生長及有機物的氧化分解造成的溶氧損耗。單從機械增氧能力來看,葉輪式>微孔式>耕水機。綜閤分析節能和增氧效果,在精養池塘養殖環境下,白天開機增氧選擇耕水機較為閤適,而夜間應急增氧選擇葉輪式更可取。試驗通過對不同機械增氧方式增氧效果和能耗的繫統比較,為閤理選擇和使用增氧方式提供瞭一定的參攷價值。
당전대우재정양지당중여하배제화합리사용불동궤계증양방식결핍계통적비교연구。해문위료탐토고온계절청호천기불동궤계증양방식대지당용양전천조공적영향,시험설계여하:우하천고온계절집중대정양지당응용3충불동증양방식,재청호천기적백천화야간진행증양효과시험。결과발현:무론증양궤개계여부,지당적용양도존재명현적주야기복,차재오후출현봉치。증양궤적개계증강료상하수층교환,삭감료양차,감소료상층용양적일출손실,제승료하층수체적저용양수평。지당상층용양기복정도대우하층,하층용양변화체후우상층(하층용양출현봉치락후우상층약2~5 h),차저충체후성위증양궤운행소삭약。야간증양능향지당보충용양,단잉불족이미보어류화부유생물적대사、미생물적생장급유궤물적양화분해조성적용양손모。단종궤계증양능력래간,협륜식>미공식>경수궤。종합분석절능화증양효과,재정양지당양식배경하,백천개궤증양선택경수궤교위합괄,이야간응급증양선택협륜식경가취。시험통과대불동궤계증양방식증양효과화능모적계통비교,위합리선택화사용증양방식제공료일정적삼고개치。
Aerators are essential in semi-intensive and intensive aquaculture to maintain an environment congenial to the physiological requirements of the cultured organisms. In an intensive aquaculture, the full oxygen demand of the cultured species cannot be met through natural aeration only. Therefore, artificial aeration is essential. In past years, various types of aerators have been developed to maintain the desired concentration of dissolved oxygen (DO) in the pond water to improve the energy efficiency of the oxygen mass-transfer process. In the present study, it is intended to compare the dynamical efficiency and economic performance of three different aeration approaches, including paddle wheel aerators, diffused-air systems, and water cultivators at different initial DO concentrations of ponds and operating durations of aerators. The study involved a typical Chinese grass carp culture with commonly practiced stocking density and feeding. The comparison included two parts:daytime and nighttime experiments with a repeated measurement design for each one. In the daytime experiment, the paddle wheel aerators and diffused-air systems were operated between 12:00 and 16:00 and the water cultivators between 8:00 and 18:00. In the nighttime experiment, the three aeration systems were all operated between 0:00 and 6:00. Based on the investigation, phytoplankton photosynthesis on sunny days was still the main source for DO replenishment in such intensive culture ponds since aerators were not operated all day. The operation of aerators enhanced water exchange between the upper and lower layers of water, decreased the escape of DO in the daytime due to over-saturation, and increased the total stock of DO. Accordingly, aerators reduced the risks of fish raising their heads above water to breathe in the night/dawn and were beneficial for fish feeding. The diurnal variation of DO in the upper layer of water was greater than that in the lower layer and displayed dis-synchronization which could be attenuated by mechanical mixing/aeration. The mixing/aeration capacity of paddle wheel aerators and diffused-air systems were significantly higher than that of cultivators, but the paddle wheel aerators also increased the oxygen consumption rates during the night in comparison to the cultivators, possibly due to the enhanced decomposition of organic matter promoted by water circulation. In the current case, the mechanical aeration capacity of cultivators, diffused-air systems, and paddle wheel aerators were 0.22, 3.2, and 4.53 kg/h, corresponding to a decrease rate of DO 0.58 mg/h for the cultivators, 0.43 mg/h for the diffused-air systems, and 0.27 mg/h for the paddle wheel aerators during nighttime. Energy consumption in the daytime was in the following order:paddle wheel aerators (12.0 k W·h)>diffused-air systems (6.4 k W·h)>cultivators (0.8 k W·h). Based on the dynamic efficiency and energy savings, the cultivator is more suitable for mixing/aeration in the daytime, while the paddle wheel more effectively mitigates oxygen depletion during the night.