CN104237056B - A kind of silo internal point grain measurement of moisture content method based on warm and humid monitoring - Google Patents

Abstract

The present invention provides a kind of silo internal point moisture method for quick based on temperature-humidity monitoring.In hypothesis grain heap on the basis of moisture relative equilibrium, establish relational model between silo internal point grain equilibrium water conten and temperature and humidity, and determine each initial parameter values in formula by static weighing method and multivariate statistical regression.To establishing different grain variety parameter database after corrected model parameter.Based on the silo internal point temperature/humiditydetection detection system set up, gather the epidemic disaster that grain internal point is corresponding.Pass through data acquisition, the temperature corresponding to the internal single-point of silo or multiple spot and rh value can be obtained, the parameters of formula value that system directly invokes the quick detection formula of moisture corresponding with different corn calculates, thus realizes the quick detection of the internal single-point of silo or multiple spot moisture.

Description

A kind of silo internal point grain measurement of moisture content method based on warm and humid monitoring

Technical field

The present invention relates to the moisture monitoring in grain storage safety management and computational methods, a kind of based on temperature-humidity monitoring Silo internal point moisture detecting method, the method realizes directly detecting the equilibrium water of grain by the internal humiture observation system of silo Point.

Background technology

Grain is important agricultural product, is the valuable source being related to national economy.The existing substantial amounts of grain depot of China, often There is the silo of a number of multi-form in individual storehouse, it is intended to guarantee the safety of grain.Grain condition monitoring is the key of silo management. At present, the common method of monitoring grain feelings is both at home and abroad, in the internally installed temperature sensor of silo, by monitoring the temperature of grain heap, Evaluate the quality safety situation of grain, and take the ventilatings such as the cooling of suitable intensity, precipitation, modulation.Here exist One problem, the safe condition of grain is not only one index of cereal temperature, and should include moisture and grain of grain The humiture of grain surrounding air, the most single dependence cereal temperature judges, the case of many erroneous judgements occurs, sometimes Cause the going mouldy of grain, sometimes cause insect pest, sometimes cause quantity to lose.In order to solve this problem, silo internal point wet Degree monitoring technology is moving towards application, and the eighties in 20th century, China expert proposed the grain expressed with relative humidity and absolute humidity Heap damp and hot regulation and control math equation (Wu Zidan, 1987), gives (definitely) humidity and grain moisture content and the functional relationships of temperature relatively System, journey has been established the technical foundation of China's silo force ventilation, has been referred to as WU model.WU model equation is as follows:

${\mathrm{ERH}}_r=\exp \{\frac{\frac{D}{222}\×(e^{\frac{B_1-M}{A_1}}-e^{\frac{B_2-M}{A_2}})\×(1737.1-\frac{474242}{273+t})+D\×\left({1-e}^{\frac{B_1-M}{A_1}}\right)+202}{87.72}$

In formula: ERH_rFor grain equilibrium relative humidity (ERH) (%), M is grain moisture content (% wet basis), t be cereal temperature (DEG C), A₁、B₁、B₂, D be 5 parameters of WU model.

Within 1991, the Ministry of Commerce is based on WU model, has issued " mechanical ventilation in grain storage technical regulation "；Within 2002, upgrade to industry Standard (LS/T1202-2002).The industry standard " mechanical ventilation in grain storage technical regulation " (LS/T1202-2002) issued for 2002, It it is exactly the task management parameters such as temperature, humidity and dew point being combined and carrying out silo safety.WU model essence solves grain Functional relationship between the internal equilibrium relative humidity (ERH) of grain of heap or the absolute humidity of grain and the moisture content of grain and cereal temperature, Owing to the inverse function relation of this relation is never solved, so unified to function and inverse function relation among industry standard Express with chart, so with look into curve diagram method determine grain machinery ventilate technical conditions.Look into curve diagram method can lead to Cross the equilibrium relative humidity (ERH) of grain or the absolute humidity of grain and the temperature of grain, indirectly check in the moisture of grain, it is also possible to pass through Ventilation condition changes, and predicts the moisture of grain, but so set up grain machinery ventilate automatically control or intelligence control system and In exploitation silo, grain measurement of moisture content and prediction instrument there is inconvenience more.

Therefore, the present invention is assuming in grain heap on the basis of moisture relative equilibrium, it is provided that silo internal point grain equilibrium water conten and temperature And direct relational model between humidity, and the equilibrium water conten realizing detecting grain with this.Application grain equilibrium water conten and balance thereof The relational model of relative humidity and temperature is just easily determined cooling ventilation, precipitation ventilates and the damp condition of conditioning and aeration, for machine The management of tool ventilating provides important evidence.

Summary of the invention

The present invention is directed to problem above proposes a kind of silo internal point grain measurement of moisture content method based on warm and humid monitoring, the method Relatively easy, amount of calculation is little, can effectively ensure that detection grain moisture content, reduces erroneous judgement of ventilating.

For realizing said method, the application is achieved in that

Step 1, utilizes static weighing method to measure different cultivars sample desorbing and equilibrium water mark of absorption under different epidemic disaster According to.

Step 2, utilizes the data set of step 1, selects and set up grain moisture content, temperature and humidity relational model, according to foundation Model carry out parameter value estimation and verification, determine and set up different grain variety parameter database after model parameter value.

Step 3, sets up the internal warm and humid monitoring system of silo, utilizes this system detect the temperature and humidity of silo internal point and call Model determined by step 2 and model parameter, calculate the internal single-point of silo or multiple spot moisture value.

Step 4, according to country's mechanical ventilation in grain storage standard LS/T1202-2002, in analysis temperature, humidity and moisture distribution On the basis of, carry out silo cooling, precipitation, the task management such as quenched.

Further, described step 1 comprises the following steps:

Step 1.1, after sample screening, processed under constant low temperature.For desorption curve, seed sample is used and adds water And low temperature is after uniform 2 weeks, is balanced determination of water.

Step 1.2, equilibrium water conten is tested；Different saturated salt solution is utilized to produce constant vapour pressure under different steady temperatures, Static weighing method is used to measure absorption and the desorbing equilibrium water conten of different grain kind.

Further, in described step 2, select and set up grain moisture content, temperature and humidity relational model is EMC=f (ERHr, T) Form:

$\mathrm{EMC}=\sqrt[\mathrm{\α}]{\frac{\ln (1-{\mathrm{ERH}}_r)-\ln {\mathrm{ERH}}_r-A-C\·T^{\mathrm{\β}}}{B}}$

Wherein, EMC is moisture (fractional representation), ERH_rThe relative humidity (fractional representation) of corn, A, B, C, α, β is equation parameter, and T is ambient temperature (DEG C).By the test data in step 1 to model parameter value estimate and from different product Kind grain epidemic disaster and water relation experiment obtain parameter value carry out contrasting, correcting, so that it is determined that parameter value.According to gained Parameter value sets up the parameter database of various grain, the query calls when reality is measured.

Formula described in step 2, can make α, β be respectively 1 and simplify further, available 3 parameter water content detection models:

$\mathrm{EMC}=\frac{\ln (1-{\mathrm{ERH}}_r)-\ln {\mathrm{ERH}}_r-A-C\·T}{B}.$

Further, described step 3 comprises the steps:

Step 3.1, based on the silo networking multiple spot Temperature and Humidity built and control system, gathers grain internal point corresponding Epidemic disaster；By data acquisition, the temperature corresponding to the internal single-point of silo or multiple spot and rh value can be obtained.

Step 3.2, model and parameter determined by invocation step 2, calculate the internal single-point of silo or multiple spot moisture value.

Step 3.3, on the display interface set up, by display or LED real-time digital, chart display silo internal point grain Food temperature, humidity and moisture.

Further, in described step 4, mechanical ventilation in grain storage standard LS/T1202-2002 such as following table:

In table, t₁, t₂It is respectively atmospheric temperature and cereal temperature, t_l1, t_l2It is respectively atmospheric dew point temperature and grain dew point temperature, Ps₁For air absolute humidity, Ps₂It is t for grain temperature₂Time grain absolute humidity values, Ps₂₁Subtract 1% for grain moisture content and grain temperature etc. In atmospheric temperature t₁Time absolute humidity values, Ps₂₂Add 2.5% for grain moisture content man and grain temperature is equal to atmospheric temperature t₂Time absolute Humidity value, Ps₂₃For current grain temperature t₂The grain absolute humidity values that lower grain moisture content adds 2.5%.

The invention has the beneficial effects as follows: temperature-humidity monitoring based on silo internal point, it is provided that a kind of simple and clear moisture detecting method, Solve during foodstuff preservation manages, determine the inconvenience of grain moisture content by looking into curve diagram method, decrease grain security shape The erroneous judgement of state, this method can be as water content detection in silo, the key technology predicting and control.

Accompanying drawing explanation

Accompanying drawing described herein is used for providing a further understanding of the present invention, constitutes the part of the application.In the accompanying drawings:

Fig. 1 is the schematic flow sheet of a kind of silo internal point grain measurement of moisture content method based on warm and humid monitoring of the present invention.

Fig. 2 is parameter correction iterative process.

Fig. 3 is the TT&C system block diagram of the internal warm and humid monitoring system of silo in the present invention.

Detailed description of the invention:

With embodiment, the present invention is described in further detail below in conjunction with the accompanying drawings.

As it is shown in figure 1, a kind of silo internal point moisture detecting method based on temperature-humidity monitoring, specifically include following steps:

Step 1, utilizes static weighing method to measure different cultivars sample desorbing and equilibrium water mark of absorption under different epidemic disaster According to.

Step 2, utilizes the data set of step 1, selects and set up grain moisture content, temperature and humidity relational model, according to determining Model carry out parameter estimation and verification, obtain and set up different grain variety parameter database after optimal model parameter value.

Step 3, sets up the internal warm and humid monitoring system of silo, utilizes this system detect the temperature and humidity of silo internal point and call Model determined by step 2 and model parameter, calculate the internal single-point of silo or multiple spot moisture value.

Step 4, according to country's mechanical ventilation in grain storage standard LS/T1202-2002, in analysis temperature, humidity and moisture distribution On the basis of, carry out silo cooling, precipitation, the task management such as quenched.

Wherein, the relational model in step 1 is set up and is determined as follows:

The first step, preparation of samples.After sample screening, phosphorus pentoxide solid evaporation is used to reduce in grain under constant low temperature Monolayer water, makes seed initial water content drop to 5.0% (wet basis) below.For desorption curve, seed sample is used and adds water And low temperature is after uniform 2 weeks, is balanced determination of water.

Second step: equilibrium water conten is tested.Utilize 9 kinds of saturated salt (chlorination file, potassium acetate, magnesium chloride, potassium carbonate, magnesium nitrate, Copper chloride, sodium chloride, potassium chloride, potassium nitrate) solution produces constant steaming under 5 kinds of steady temperatures (10,20,25,30 and 35 DEG C) Vapour pressure, uses static weighing method to measure Oryza glutinosa equilibrium water conten.The equilibrium humidity that various salts produces at different temperatures such as following table:

Followed by step 2, the data obtained according to step 1 pilot scale test, regression equation solves.Utilize the non-thread of SPSS software Property homing method respectively matching difference corn resolving and parameters corresponding in model during absorption, grain moisture content of the present invention Detection model is EMC=f (ERH_r, T) and form:

$\mathrm{EMC}=\sqrt[\mathrm{\α}]{\frac{\ln (1-{\mathrm{ERH}}_r)-\ln {\mathrm{ERH}}_r-A-C\·T^{\mathrm{\β}}}{B}}$

ERH in described formula_rBeing the relative humidity (fractional representation) of corn, EMC is moisture (fractional representation).A、B、C、 α, β are equation parameters, t_αIt is ambient temperature (DEG C).Described formula is 1 to simplify further, before simplification by making α, β It is called five parameter WU.W.F models, after simplification, is called three parameters simple and clear WU.W.F model.

Owing to the foundation of model is based on static weighing method, therefore also need to carry out humiture and the moisture pass of different grain kind at silo System's experiment.Sampled measurements is gone out grain moisture content and contrasts with the model parameter value estimated value obtained by the test data in step 1, By continuous iterative computation, adjust model parameter, be finally reached error minimize.

As shown in Figure 2, step is as follows for concrete trimming process:

Original model parameter has passed through static weighing method measurement and has determined, initial parameter values A, B, C, α, β of matching is inputted In model, just can calculate the moisture of archetype.The actual water of different humiture grain samples is measured by oven drying method Divide content, the moisture value that comparison model obtains and the error surveying moisture value.If error size is unsatisfactory for the requirement of precision, then Adjust parameter, calculate again and compare.

Constantly adjusted initial parameter values by iterative process, reduce the mean square deviation of model moisture and actual measurement moisture.When full Foot required precision time iteration terminate, the model parameter after can being adjusted.

By different cultivars grain is measured, set up the parameter database of various grain, the query calls when reality is measured. Model parameter after adjustment such as table 2 to table 5.Determined by different grain kinds grain equilibrium water conten detection formula in parameters such as Table 2,3,4,5 is respectively supplemental characteristic and the degree of fitting of the crops such as Oryza glutinosa, Semen Maydis and Semen Tritici aestivi.R²It it is the coefficient of determination；MRE% is Average relative percentage error.

Table 2 is with ERH=f (EMC, t) the three parameters simple and clear WU.W.F model parameter value that form is expressed

Table 3 is with EMC=f (ERH, t) the three parameters simple and clear WU.W.F model parameter value that form is expressed

Table 4 is with ERH=f (EMC, t) the five parameter WU.W.F model parameter values that form is expressed

Table 5 is with EMC=f (ERH, t) the five parameter WU.W.F model parameter values that form is expressed

Following step 3, sets up the internal warm and humid monitoring system of silo, utilizes this system to detect the temperature of silo internal point and wet The model parameter value that degree, the water content detection model in calling system and different corn are corresponding, calculates the internal single-point of silo or multiple spot water Score value.

Accompanying drawing 3 shows the block diagram of the internal warm and humid monitoring system of silo.The present invention is in order to realize gathering inside silo accurately and real-time The moisture content of point, uses wireless sensor network node to be monitored the humiture of different depth Oryza glutinosa in grain heap, by gathering eventually End gathers and shows collection data.Wireless transmission method is utilized to send to host computer server, the data gathered according to equilibrium water Sub-model prediction Rice Kernel Moisture Content, it is achieved the real-time monitoring of Rice Kernel Moisture Content, temperature, humidity in silo, meets reliability and reality The demand of time property.

1) based on the silo networking multiple spot Temperature and Humidity built and control system, gathered in grain by Temperature Humidity Sensor The epidemic disaster that portion's point is corresponding.By gathering signal, after filtering and signal converts the data gathered with temperature sensor to humidity sensor Send together and store in host computer, thus obtaining the temperature corresponding to the internal single-point of silo or multiple spot and rh value.

2) model parameter value that in calling system data base, water content detection model is corresponding with different corn, utilizes the epidemic disaster gathered Value calculates the internal single-point of silo or multiple spot moisture value.

3) on the display interface set up, by display or LED real-time digital, the temperature of chart display silo internal point, wet Degree and moisture.

Last step 4 is through the humiture of grain epidemic disaster and equilibrium water conten and air, and system determines whether beyond setting Scope.If going beyond the scope, sound and light alarm is also aerated task management according to industry ventilation standard (LS/T1202-2002). If meeting, cooling is ventilated, precipitation ventilates and the temperature and humidity conditions of conditioning and aeration, host computer send Signal Regulation ventilation installation, from And carry out force ventilation task management.

In the present invention, the internal warm and humid monitoring system of set up silo is mainly made up of hardware components and software section.

Hardware components specifically includes that microprocessor, display, input-output unit, alarm unit, memory element, humiture Sensor group (temperature-humidity monitoring point is no less than 1), controlled quentity controlled variable input-output unit composition.Microprocessor is used for processing, analyzing With control data；Display is for showing detection and analysis result in graphical form, and shows people's machine information exchanging window；Input Output unit includes keyboard, printer and mouse；When unsafe condition occurs in alarm unit, send alarm with acoustooptic form；Temperature Humidity sensor is the temperature and humidity of diverse location in monitoring silo, the form of limited/infinite net transmit number to microprocessor According to；Controlled quentity controlled variable input-output unit is for controlling the equipment of force ventilation operation.

Software section specifically includes that system management module, temperature-humidity signal acquisition module, moisture computing module, controlling alarm mould Block, prediction module.System management module is for coordinating the data direction of transfer between hardware, software and people；Temperature-humidity signal is adopted Collection module patrols and examines the temperature and humidity of diverse location in silo by certain sample frequency, and stores；Moisture computing module foundation The temperature gathered and (relative humidity of grain) humidity, calculate the moisture of grain and store；Alarm control module according to Temperature, humidity and three parameters of moisture, be aerated operation according to industry standard (LS/T1202-2002), when uneasiness occur Sound and light alarm is carried out during full situation；Prediction module, according to the forecast data of FUTURE ENVIRONMENT weather, carries out grain security state in silo Prediction.

A kind of based on temperature-humidity monitoring the silo internal point moisture detecting method of the present invention, is not limited by above-mentioned case study on implementation, Every utilize the principle of the present invention, method or form, through conversion, replace or combine formed technical scheme all in the present invention Protection domain in.

Claims (2)

1. a silo internal point grain measurement of moisture content method based on warm and humid monitoring, it is characterised in that comprise the following steps:

Step 1, utilizes static weighing method to measure different cultivars sample desorbing and equilibrium water mark of absorption under different epidemic disaster According to；

Step 2, utilizes the data set of step 1, selects and set up grain moisture content, temperature and humidity relational model, according to foundation Model carry out parameter value estimation and verification, determine and set up different grain variety parameter database after model parameter value；

Step 3, sets up the internal warm and humid monitoring system of silo, utilizes this system detect the temperature and humidity of silo internal point and call Model determined by step 2 and model parameter, calculate the internal single-point of silo or multiple spot moisture value；

Step 4, according to country mechanical ventilation in grain storage standard LS/T 1202-2002, in analysis temperature, humidity and moisture distribution On the basis of, monitoring silo, carry out silo cooling, precipitation, the task management such as quenched；

Wherein, described step 1 comprises the following steps:

Step 1.1, after sample screening, processed under constant low temperature, for desorption curve, seed sample is used and adds water also After uniform 2 weeks of low temperature, it is balanced determination of water；

Step 1.2, equilibrium water conten is tested；Utilize different saturated salt solution to produce constant vapour pressure under different steady temperatures, adopt The equilibrium water conten of different grain kind is measured with static weighing method；

In described step 2, select and set up grain moisture content, temperature and humidity relational model is EMC=f (ERH_r, T) and form:

$EMC=\sqrt[\mathrm{\α}]{\frac{ln(1-{\mathrm{ERH}}_r)-\ln {\mathrm{ERH}}_r-A-C\·T^{\mathrm{\β}}}{B}}$

In, EMC is moisture (fractional representation), ERH_rBeing the relative humidity (fractional representation) of corn, A, B, C, α, β are Equation parameter, T is ambient temperature (DEG C)；By the test data in step 1 to model parameter value estimate and with different cultivars grain Food epidemic disaster and water relation experiment obtain parameter value carry out contrasting, correcting, so that it is determined that parameter value, according to parameters obtained Value sets up the parameter database of various grain, the query calls when reality is measured；

In described step 3, comprise the steps:

Step 3.1, based on the silo networking multiple spot Temperature and Humidity built and control system, gathers grain internal point corresponding Epidemic disaster；By data acquisition, the temperature corresponding to the internal single-point of silo or multiple spot and rh value can be obtained；

Step 3.2, model and parameter determined by invocation step 2, calculate the internal single-point of silo or multiple spot moisture value；

Step 3.3, on the display interface set up, by display or LED real-time digital, chart display silo internal point Cereal temperature, humidity and moisture.

A kind of silo internal point grain measurement of moisture content method based on warm and humid monitoring the most according to claim 1, it is characterised in that step In rapid 2, describedFormula, can make α, β be respectively 1 letter further Change, available 3 parameter water content detection models:

$EMC=\frac{ln(1-{\mathrm{ERH}}_r)-\ln {\mathrm{ERH}}_r-A-C\·T}{B}.$