Design of greenhouse temperature and humidity wireless control system based on CC3200

Referring to the shortages that the process of traditional greenhouse measurement by using thermometer and hygrometer is complex,the measurement result is not accurate,and the control system operation is cumbersome,a greenhouse temperature and humidity(TH)control system based on CC3200 is designed.The system uses FPGA as the main controller,sends the TH signals to the wireless module CC3200 by controlling DHT22.The proposed system realizes the remote transmission of data and the automatic control of system.

Temperature Intelligent Control System of Large-Scale Standing Quench Furnace

Considering some characteristics of large-scale standing quench furnace, such as great heat inertia, evident time lag, strong coupling influence, hard to establish exact mathematical models of plant and etc, an artificial intelligent fuzzy control algorithm is put forward in this paper. Through adjusting the on-off ratio of electric heating elements, the temperature in furnace is controlled accurately. This paper describes structure and qualities of the large-scale standing quench furnace briefly, introduces constitution of control system, and expounds principle and implementation of intelligent control algorithm. The applied results prove that the intelligent control system can completely satisfy the technological requirements. Namely, it can realize fast increasing temperature with a little overshoot, exact holding temperature, and well-distributed temperature in quench furnace. It has raised the output and quality of aluminum material, and brought the outstanding economic and social benefits.

COMPUTER DECOUPLE CONTROL OF TEMPERATURE AND HUMIDITY IN PREPROCESSING CHAMBER OF AIR-CONDITIONING TEST EQUIPMENT

This paper deals with the application of decouple Control theory to temperature and humidi-ty control in air-conditioning system. The decouple control algorithm for bivariable systems isderived applicablly for air-conditioning system. The algorithm is used to design a temperatureand humidity computer control system for the preprocessing chamber of air-conditioning testequipment. The results of the real-time control experiments indicate that the decouple controlalgorithm is feasible, the control quality is improved and high control precision is achieved.

Temperature and Humidity Control in Greenhouses in Desert Areas

Water consumption can be reduced by using a greenhouse for agriculture in desert areas. We analyzed the effect of control of ventilation, sprinkler water, and solar radiation?shielding on changes of temperature and humidity in a greenhouse under various desert area conditions. We calculated the changes in temperature and humidity in a greenhouse for a whole day in four seasons, and the calculation results of water consumption with and without a greenhouse were compared. When ventilation, shielding, and sprinkler water were controlled under suitable conditions to grow orchids in a desert area, water consumption in July was only 7% of that without a greenhouse.

Visco-elastic-plastic model of deep underground rock affected by temperature and humidity

As the depth of exploitation increases,studies on constitutive models of rock affected by temperature and humidity become very important.Based on the Nishihara model,a visco-elastic-plastic rock model was established by using the coefficients of thermal and humidity expansion,thermal viscosity attenuation,humid viscosity attenuation and acceleration rheology components.We used the definition of a controlled heat circle to explain the model.The results show that the behavior of rock,affected by temperature and humidity,is stable as a function of time when the stress is lower than the first yield stress σS1;the creep rate will increase due to the effect of temperature and humidity when the stress is greater than or equal to σS1;the creep rate will accelerate at an increasing rate when the stress is greater than or equal to the second yield stress σS2,which results in a failure of the roadway.The model derived in this study can completely describe visco-elastic-plastic characteristics and reflects the three stages of rock creep.

Hybrid intelligent control of combustion process for ore-roasting furnace

Because of its synthetic and complex characteristics, the combustion process of the shaft ore-roasting furnace is very difficult to control stably. A hybrid intelligent control approach is developed which consists of two systems： one is a cascade fuzzy control system with a temperature soft-sensor, and the other is a ratio control system for air flow with a compensation model for heating gas flow and air-fuel ratio. This approach combined intelligent control, soft-sensing and fault diagnosis with conventional control. It can adjust both the heating gas flow and the air-fuel ratio in real time. By this way, the difficulty of online measurement of the furnace temperature is solved, the fault ratios during combustion process is decreased, the steady control of the furnace temperature is achieved, and the gas consumption is reduced. The successful application in shaft furnaces of a mineral processing plant in China indicates its effectiveness.

Reliability Evaluation of Wind Power Converter Under Fault-tolerant Control Scheme with Quantification of Temperature and Humidity Effects

Wind power converter(WPC)is a key part of a wind power unit which delivers electric energy to power grid.Because of a large number of semiconductors,WPC has a high failure rate.This paper proposes a method to accurately evaluate the reliability of WPC,which is crucial for the design and maintenance of wind turbines.Firstly,the index of effective temperature(ET)is presented to quantify the effects of temperature and humidity on the semiconductor operation.A novel method is proposed to evaluate the lifetime and calculate the aging failure rates of the semiconductors considering the fluctuations of ET.Secondly,the failure mode and effect analysis(FMEA)of WPC is investigated based on the topology and control scheme.The conventional two-state reliability model of the WPC is extended to the multi-state reliability model where the partial working state under the fault-tolerant control scheme is allowed.Finally,a reliability evaluation framework is established to calculate the parameters of the WPC reliability model considering the variable failure rates and repair activities of semiconductors.Case studies are designed to verfify the proposed method using a practical wind turbine.

Room temperature and humidity decoupling control of common variable air volume air-conditioning system based on bilinear characteristics

Variable air volume(VAV)air-conditioning(AC)systems are widely employed to achieve a comfortable room thermal and humid environment depending on its better regulation performance and energy efficiency.In the single coil VAV AC system,conventional proportional-integral(PI)control algorithm is usually adopted to track the set-points of the room temperature and humidity by regulating the supply air flow rate and the chilled water flow rate,respectively.However,the control performance is usually not good due to the high coupling of the heat and mass transfer in the air-handling unit(AHU).A model-based control method is developed to realize the decoupling control of the room temperature and humidity according to the bilinear characteristics of the temperature and humidity variation.In this control method,a bilinear room temperature controller is used to track the room temperature set-point based on the real-time cooling load,while a room humidity controller is used to track the room humidity set-point depending on the real-time humidity load.The control performance was validated in a simulated VAV AC system.The test results show that comparing with the conventional PI control,the room temperature and humidity are controlled much more robustly and accurately by using the proposed model-based control method.

Optimization of hot-air microwave combined drying control system based on air outlet temperature and humidity monitoring

Microwave drying is one of the most important drying methods in agriculture.The online measurement and control of material dried,as a challenging research issue,is helping to improve the drying quality of the final product and the energy utilization efficiency of microwave dryers.In order to realize the online measurement of temperature in microwave drying,a detection strategy was based on the temperature and humidity monitoring at the air outlet of coupling hot air and microwave drying method.LabVIEW programming software was employed to collect the temperature and humidity signal value at the outlet of the dryer to estimate the drying degree of the material.According to the amount of moisture removal in real-time,the microwave input power was adjusted gradually in the microwave drying process.Taking potato as material dried,the microwave power of microwave and hot air coupling drying is monitored to realize the real-time regulation.The results showed that the total color difference value of the product of 3.09,the rehydration ratio of 2.92,the unit energy consumption of 17419.35 kJ/kg,and the drying rate of 0.442 g/s were obtained.The minimum comprehensive weighted score of the product was 26.36.Compared with the orthogonal experiment,the optimal drying process was obtained as the total color difference value of the product of 2.84,the rehydration ratio of 3.01,the unit energy consumption of 17419.35 kJ/kg,and the drying rate of 0.397 g/s.The minimum comprehensive weighted score of the product was 20.67,and the difference was not significant.The control strategy not only solves the non-uniform phenomenon of drying,and makes the microwave drying real-time and continuous,but also improves the drying efficiency and quality.

Development and experiment of the intelligent control system for rhizosphere temperature of aeroponic lettuce via the Internet of Things

Currently,in the conventional aeroponic system the collection of data for crop performance is quite slow,whereas such data are typically collected manually.Correspondingly,the root zone temperature is one of the most important factors affecting plant growth in aeroponics cultivation.This study aimed to obtain temperature and relative humidity data inside an aeroponic system based on the Internet of things(IoT)and automatically cool the root zone using a novel low-cost effective technique for cooling via a cooling fan connected to the Arduino board.The results revealed that the newly designed system could monitor and record the data in real-time on an internet server per hour.Furthermore,the temperature and humidity data can be displayed on the smartphone application,and be sent to the personal email weekly as an excel sheet.This system was able to maintain the temperatures inside the roots chamber between 28.7℃-29.2℃ while the maximum external temperature was 38.1℃,and the average temperature in the traditional aeroponics system was fluctuating between 29.5℃-31.5℃.The newly automated cooling system root zone system of this study showed an optimization of lettuce growth characteristics.It significantly increased the lettuce absorbance of inorganic nutrients such as N,P,and K by 45.5%,66.6%,and 45.0%,respectively,also revealed an increment of fresh weight,total chlorophyll,ascorbic acid,total carbohydrate,and total amino acids by 131.0%,26.2%,41.9%,30.7%,6.2%,respectively in comparison with the conventional aeroponic system.Therefore,this study may play a significant role in the aeroponic monitoring and control,for providing more suitable growth parameters and achieving the least human interaction.

Design and Research on New Intelligent Temperature Control System for Stove

A new intelligent temperature control system for stove was introduced. It could accomplish A/D conversion, data processing, output displaying and alarming while the temperature exceeds the given threshold. The temperature adjusting devices were bi direction SCR and heating resistor. The hardware and software were discussed in the paper.

Development of Temperature-Humidity Independent Control Air-Conditioning Unit for Residential Buildings

Cooling panels are increasingly used in domestic residential buildings.To provide medium temperature cold water for the cooling panel,and dehumidify the indoor air simultaneously,a new kind of temperature-humidity independent control air-conditioning unit was developed for single residential house by utilizing multi-variable technology.First,the supply air temperature was studied to determine the proper supply air flow rate for the humidity control.Then,the energy consumption of different temperature-humidity independent control systems was studied.The analysis indicates that unity evaporating temperature can be used to handle the moisture load and sensible heat load in two evaporators.So the unit scheme was put forward.Two evaporators were used to produce medium temperature water and dry air separately,and electric expansion valves were used to control the refrigerant distribution between the two evaporators.Then,experimental work was carried out to investigate the influence of compressor frequency,refrigerant distribution on the dehumidification capacity,energy efficiency and refrigeration capacity.In the end,the paper concludes that both compressor frequency and refrigerant distribution can control the dehumidification capacity,but the former influences the EER more than the latter,while the latter influences the refrigeration capacity more than the former.We can find a proper running point at certain sensible and latent cooling load by adjusting both compressor frequency and electric expansion valve.The energy consumption of this kind of unit was estimated and compared with present room air conditioners,which shows that it can save about 41% cooling energy consumption.

Analysis of the Effect and Solution of Geomagnetic Room Humidity on Geomagnetic Observation

It is not easy to control humidity in a geomagnetic room. If humidity is too high or the change is too fast it will lead to an abnormal change on data. The intelligent real-time humidity analysis and monitoring system of a geomagnetic room and probe can not only monitor and display the change of humidity in the geomagnetic room and send an alarm signal when it exceeds the pre-set range, but also dehumidify intelligently. One can arbitrarily control the sensor to monitor the ambient humidity of the probe in order to ensure that the data is stable and true. The design idea and main functions of the system are introduced in the paper.

Thermodynamic performance assessment of vacuum membrane-based dehumidification and air carrying energy radiant air-conditioning system(VMD-ACERS)

Temperature and humidity independent control(THIC)air-conditioning system is a promising technology.In this work,a novel temperature and humidity independent control(THIC)system is proposed,namely VMD-ACERS,which integrates vacuum membrane-based dehumidification and air carrying energy radiant air-conditioning system.This work establishes a novel coefficient of performance(COP)model of VMD-ACERS.The main parameters affecting the COP of conventional fan coil unit cooling system(FCUCS)and VMD-ACERS are investigated.The performance of FCUCS and VMD-ACERS are compared,and the energy-saving potential of VMD-ACERS is proved.Results indicate that,for FCUCS,the importance ranking of parameters is basically stable.However,for VMD-ACERS,the importance ranking will be affected by FCU and refrigerant.The most important parameters of VMD-ACERS are condensation temperature and permeate side pressure.On the contrary,superheating,subcooling are relatively less important parameters.For VMD-ACERS,it is not necessary to pursue the membrane with very high selectivity,because the selectivity of membrane would also be a less important parameter when it reaches 500.The COP of VMD-ACERS is higher than that of FCUCS when the permeate side pressure is higher than 8 k Pa.The VMD-ACERS solves two technical problems about power-saving and thermal comfort of conventional THIC,and can extend the application of THIC air-conditioning system.

Flexible and elastic thermal regulator for multimode intelligent temperature control

As nonlinear thermal devices,thermal regulators can intelligently respond to temperature and control heat flow through changes in heat transfer capacities,which allows them to reduce energy consumption without external intervention.However,current thermal regulators generally based on high-quality crystallinestructure transitions are intrinsically rigid,which may cause structural damage and functional failure under mechanical strain;moreover,they are difficult to integrate into emerging soft electronic platforms.In this study,we develop a flexible,elastic thermal regulator based on the reversible thermally induced deformation of a liquid crystal elastomer/liquid metal(LCE/LM)composite foam.By adjusting the crosslinking densities,the LCE foam exhibits a high actuation strain of 121%with flexibility below the nematic–isotropic phase transition temperature(TNI)and hyperelasticity above TNI.The incorporation of LMresults in a high thermal resistance switching ratio of 3.8 over a wide working temperature window of 60◦C with good cycling stability.This feature originates from the synergistic effect of fragmentation and recombination of the internal LM network and lengthening and shortening of the bond line thickness.Furthermore,we fabricate a“grid window”utilizing photic-thermal integrated thermal control,achieving a superior heat supply of 13.7℃ at a light intensity of 180mW/cm^(2)and a thermal protection of 43.4℃at 1200 mW/cm^(2).The proposed method meets the mechanical softness requirements of thermal regulatormaterials with multimode intelligent temperature control.

昆虫病原线虫防控苹果蠹蛾的影响因素

苹果蠹蛾(Cydia pomonella L.)是一种重要的世界性害虫,目前已在我国9个省(自治区、直辖市)发现,对我国苹果、梨等果树产业构成了严重威胁。目前,化学防治仍是防控苹果蠹蛾的主要措施,化学农药大量使用导致农药残留严重超标,影响果实品质及人类健康,因此研发新的生防制品具有重要意义。昆虫病原线虫具有主动寻找寄主害虫的能力,具有生物防治苹果蠹蛾越冬幼虫的应用潜能。本文从防控苹果蠹蛾的昆虫病原线虫高效品系以及影响其防控效果的因子(温度、湿度、紫外线等)进行了综述,以期为田间有效利用昆虫病原线虫防控苹果蠹蛾提供参考。

杭州国家版本馆恒温恒湿空调系统设计

介绍了恒温恒湿库房空调系统的设计,提出了可在库房建成初期、运行稳定期、战时等灵活切换的3种运行模式,分析了其各自的处理过程与节能性;给出了平、战时空调系统选择方案,提出了平时回收空气源热泵机组和冷水机组的冷凝热作为再热热源,战时利用新风预冷实现温湿度独立控制的方法;利用CFD模拟对室内气流组织进行了优化设计;提出了采用含湿量控制代替定露点法进行湿度控制和风机变频等控制策略。通过调试与运行,证明了各项设计措施在项目中应用的有效性。

加热炉炉温智能控制系统设计与实现

加热炉作为钢铁工业生产的重要设备,对钢坯等物料加热质量有重要的影响,能够将金属物料加热到轧制所需的温度。目前,加热炉已经应用到冶金、机械、建材、轻工等多个领域。加热炉属于高耗能窖炉,资源耗费较大,在加热过程中会随着烟气损耗大量的热量,随着科技的快速发展,智能控制技术已经运用工业生产中,通过智能控制系统对加热炉炉温进行控制,可以有效对温度进行调节,符合锻造需求。综合分析加热炉的构成以及工作原理,并介绍加热炉的炉温控制重点,并提出一种加热炉的炉温智能控制系统设计方案,希望能够提升加热炉的生产效率,改善产品质量,节约资源减少环境污染问题。

夏季不同环境控制方法对层叠式笼养肉鸭舍内环境的影响

为研究与优化夏季高温高湿条件下层叠笼养肉鸭舍环境控制方法,试验选取设施结构与养殖工艺完全相同的两栋鸭舍,根据温度变化将对照舍设置为3段式通风管理,试验舍采用5段式通风管理,研究不同环控策略对舍内温度、湿度、风速与CO_(2)质量浓度的影响。结果显示:测试期间,试验舍与对照舍内平均温度范围分别为23.5~28.9℃、25.5~30.9℃,试验舍内平均温度波动低于对照舍,最大温差达到4.3℃;对照舍12∶00~24∶00时平均温度明显高于试验舍,而平均相对湿度却低于试验舍。两栋舍内温度沿纵向通风呈上升趋势,同时相对湿度呈下降趋势。12∶00~24∶00期间,试验舍于横向、纵向与垂直方向上各区域温度均显著低于对照舍(P<0.05),同时00∶00~24∶00相对湿度均显著高于对照舍(P<0.05)。00∶00~12∶00时,两栋舍前端、对照舍上与中层温湿指数(THI)为76.23~77.71,其余区域THI为78.06~79.26;12∶00~24∶00期间,试验舍除底层THI为80.46,其余区域THI为74.26~76.77,而对照舍所有区域THI为79.29~80.52,属于中度应激。试验舍与对照舍风速分别为0.99~1.25 m/s、0.45~1.20 m/s,且CO_(2)质量浓度分别为1198~1396 mg/m^(3)、1154~1570 mg/m^(3),试验舍内风速与CO_(2)质量浓度波动均小于对照舍。与对照舍相比,试验舍肉鸭成活率显著提高(P<0.05)。研究结果提示夏季层叠笼养肉鸭舍采用5段式通风管理,可有效改善舍内环境质量、缓解肉鸭热应激程度。

基于回归分析的奶牛热应激-喷淋时长控制模型的构建

为了实现根据环境温湿度智能调控喷淋时长以保证奶牛降温效果的同时控制用水量,试验以西北农林科技大学畜牧教学试验基地的24头泌乳期荷斯坦奶牛为研究对象,于2022年5月13日—8月12日采集奶牛自愿喷淋时长(表征奶牛降温需求的喷淋时长)和牛场环境温湿度数据,共采集92 d,前87 d的数据用于奶牛热应激-喷淋时长控制模型构建,后15 d的数据用于模型验证;2022年5月20日—7月4日,每天早中晚采集3次奶牛呼吸频率(表征奶牛热应激严重程度)数据,共采集46 d;利用采集的牛场环境温湿度数据,通过6种公式计算出环境温湿指数(temperature-humidity index,THI)数据(THI1~THI6);分析THI1~THI6与奶牛平均呼吸频率相关性以筛选适合陕西关中地区的THI;以筛选THI的不同历史时长的平均THI[包括当前喷淋时刻THI(THI_(cur))和当前喷淋时刻前1,2,3,4,5天平均THI(THI_(1d-avg)、THI_(2d-avg)、THI_(3d-avg)、THI_(4d-avg)、THI_(5d-avg))]作为自变量,以喷淋时长的对数值ln(t_(spray))作为因变量分别进行回归分析,以决定系数(R~2,表示模型的拟合度)、残差标准差(residual standard error,RSE)和P值为指标评价回归模型,筛选最优时段THI与喷淋时长的一元线性回归模型;并对筛选的回归模型以均方误差(mean squared error,MSE)、平均相对误差(mean relative error,MRE)、相关系数(r)和P值为指标进行性能验证。结果表明:THI1~THI6与奶牛平均呼吸频率均呈极显著相关(P<0.01),且相关系数接近,在0.88~0.90之间;其中THI2与奶牛平均呼吸频率相关性最高,相关系数为0.90,选取THI1(研究中较常用)和THI2作为奶牛热应激-喷淋时长控制模型的输入参数;不同时段THI1、THI2与ln(t_(spray))的回归模型的R~2、RSE变化趋势相似,即THI1中THI1_(1d-avg)、THI1_(2d-avg)、THI1_(3d-avg)、THI1_(4d-avg)、THI1_(5d-avg)与ln(t_(spray))的回归模型的R~2、RSE均优于THI1_(cur),THI2中THI2_(1d-avg)、THI2_(2d-avg)、THI2_(3d-avg)、THI2_(4d-avg)、THI2_(5d-avg)与ln(t_(spray))的回归模型的R~2、RSE均优于THI2_(cur),其中THI1中的THI1_(1d-avg)和THI2中的THI2_(1d-avg)与ln(t_(spray))的回归模型最佳;THI1_(1d-avg)与ln(t_(spray))的回归模型的预测值与实际值的r为0.76,MSE为0.83,MRE为13.77%;THI2_(1d-avg)与ln(t_(spray))的回归模型的预测值与实际值的r为0.77,MSE为0.82,MRE为13.55%。说明可以采用喷淋前1天的平均THI来预测奶牛平均喷淋时长。