The Research Of Recirculation Aquaculture Thermostat System Technology

Recirculating Aquaculture System(RAS)refers to a culture mode in which aquaculture water is purified through biological,chemical and physical methods to recycle all or part of the water.This model has the advantages of water saving,land saving,strong controllability,low risk,intensification,safe and reliable product quality,etc.It is an internationally recognized dominant direction in the development of aquaculture in the 21 st century.Water temperature regulation is crucial to the production and management of circulating aquaculture.On the one hand,water temperature is an important water quality parameter.It can directly affect the physiological behavior of fish,and it can also indirectly affect other water quality parameters(such as PH,TAN,DO,TSS,etc.).On the other hand,water temperature control consumes more energy and increases operating costs.Therefore,the design effect of the water temperature control system will seriously affect the aquaculture production,aquatic product quality,and total revenue of RAS.Therefore,there are more and more researches on the water temperature regulation system for circulating aquaculture in China.In this paper,the opening experiment of China Aquatic Science Scientific Research Fisheries Water Purification Technology and System was used as the experimental site,and the environment of the circulating aquaculture workshop was continuously tested.The test results showed that during the period from February to March in Shanghai in February 2018,the temperature in the circulating aquaculture workshop was relatively stable at 12-15°C,and the relative humidity was maintained at 80-85%,that is,the aquaculture workshop was more volatile than the indoor temperature.Small highhumidity environment.Based on the investigation of the environmental conditions of the circulating aquaculture workshop,this paper focuses on the design of the temperature control system for the largest aquaculture pond with heat loss.According to the process characteristics of the recirculating aquaculture system and the flow state of the aquaculture pond,a zerodimensional dynamic temperature model of the recirculating aquaculture pond was constructed using the principle of heat balance.The Euler equation is used to solve the model,and the measured data is used to verify the accuracy of the constructed temperature model.The results show that the average error in the heating stage is 1.22°C,and the average relative error is 2.21%.In the operation stage,when the experimental system circulation rate is set to 1 times/h,2 times/h,and 4 times/h respectively,the simulated and measured values of the water temperature are obtained.The maximum average errors were 0.43°C,0.226°C,and 0.52°C,respectively,and the maximum relative errors were 2.69%,1.61%,and 2.76%,respectively.The simulated value is in good agreement with the measured value.The model can be used for practical design research.Afterwards,the zero-dimensional model and measured data were used to study the relationship between the Tw of the aquaculture water temperature and the room temperature,the inlet temperature and the circulation rate,and the heat dissipation of the culture tank.The results show that the steady state of water temperature can be adjusted by changing the room temperature and inlet water temperature,and the relationship is given in the text;and the formula for the heat loss in the culture pond is given.Finally,based on design parameters in Shanghai,this paper designs a set of water temperature control system based on “solar + generating units”.The design of the temperature control system,the design of the solar collector and the selection of the main equipment such as the heat pump unit,the water pump and the heat exchanger are described in detail.And using the stable operation of the temperature control system is measured data to study the temperature control system.The results showed that the “solar+generator” thermostat system fully meets the daily operation requirements of the aquaculture system;the system has good stability and the temperature of the aquaculture pond under various climatic conditions(sunny,cloudy,rainy,cloudy,etc.)They are relatively stable at 22°C;using the "solar+generator" thermostat system,the monthly energy consumption of the water temperature regulation is reduced by 11.1 tons of standard coal,which greatly reduces the emission of environmental pollutants.