CN102607994A - Method for measuring concentration of halogenated salt hydrate slurry - Google Patents

Abstract

The invention relates to a method for measuring the concentration of halogenated salt hydrate slurry. According to the invention, the method comprises the following steps of: measuring the temperature of slurry which is in a stable state, then taking an appropriate amount of slurry, heating the slurry, completely melting the slurry to form a solution, and measuring the density of the solution under a certain temperature by using a density bottle method; predetermining a standard curve representing the relationship between the concentration and the density of the solution under a certain temperature, and calculating the concentration of the solution according to the standard curve; in a stable system, calculating the concentration of liquid phase in the slurry according to a phase diagram and the slurry temperature when the liquid phase in the slurry is in a saturated state; and finally calculating the slurry concentration according to the concentration of the solution which is prepared after the slurry is completely molten and the concentration of the liquid phase in the slurry. The method disclosed by the invention can be used for accurately, simply and conveniently and economically measuring the concentration of solid particles in a liquid-solid dual-phase system and simultaneously eliminating the temperature interference and has the advantage of wide concentration measurement range.

Description

The measuring method of halide salt hydrate slurry bulk concentration

Technical field

The present invention relates to the measuring method of solid concentration in the liquid-solid two-phase system, be specifically related to a kind of measuring method of halide salt hydrate slurry bulk concentration.

Background technology

In recent years, air conditioning electricity load shared ratio in power consumption is increasing, and electric load peak-valley difference is round the clock constantly widened, and an important means that addresses this problem is exactly a Technology of Cold Storage Air Conditions.At present, one of cold-storage Study on Technology focus is to become the hydrate slurry cold-storage on basis mutually.The liquid-solid two-phase fluid that the hydrate slurry is made up of the halide salt hydrate crystal and the halide salt WS.And confirming of hydrate slurry bulk concentration is most important concerning the phase change cold-storage The Application of Technology.At present, the measuring method of slurry concentration comprises supercritical ultrasonics technology, optical means, conductance method, calorimetry etc.Supercritical ultrasonics technology is to utilize the speed difference of ultrasound wave in different medium to carry out concentration determination, and its equipment manufacturing cost is expensive, is not easy to widespread use.Optical method mainly contains nephelometry, online granule density appearance etc.The nephelometry antijamming capability is weak and can only be used for very rare suspension system.And online granule density appearance cost is very expensive, has limited its range of application.The principle of conductance method is based on the characteristics that different solid loads can cause the different electric conductance.Its shortcoming is that the purity of water and slurry temperature influence very big to conductivity.Calorimetry is to melt the heat that is absorbed fully and confirm solid load through measuring a certain amount of slurry, the differential scanning calorimeter that uses in the measuring process cost an arm and a leg and measuring operation complicated.Major part all needs special devices in the method for more than mentioning, and the price of these equipment generally all compares expensive, thereby has limited the widespread usage of these methods.

Summary of the invention

The objective of the invention is to overcome the deficiency that above-mentioned prior art exists, a kind of measuring method of halide salt hydrate slurry bulk concentration is provided.This measuring method can be measured the concentration of solid particles in the liquid-solid two-phase system accurate, easy, economically, can eliminate temperature disturbance simultaneously, and has the wide advantage of the concentration range of measurement.

The objective of the invention is to realize through following technical scheme:

The present invention relates to a kind of measuring method of halide salt hydrate slurry bulk concentration, comprise the steps:

A, the temperature of the said slurry that is in steady state (SS) is measured, taken out said slurry then, it is heated it is melted fully be solution, utilize the density bottle method to measure the density of said solution;

The volume of density bottle can be demarcated by the distilled water of known density:

$V=\frac{m_1-{\mathrm{<figure-callout\; id="0"\; label="m"\; filenames="HDA0000139697780000022.png,HDA0000139697780000031.png"\; state="\{\{state\}\}">m</figure-callout>}}_0}{{\mathrm{\&rho;}}_{H_{2}O}}---\left(1\right)$

The density of the solution of surveying can be calculated by formula (2):

${\mathrm{\&rho;}}_{\mathrm{sol}}=\frac{m_2-m_0}{V}---\left(2\right)$

In formula (1), (2), V is the density bottle volume, m ₁For filling the density bottle quality of distilled water, m ₀The quality of empty density bottle, m ₂For filling with the density bottle quality of solution,

For its value of the density of distilled water by the decision of distilled water temperature, ρ _SolBy the density of survey solution;

B, the halide salt solution through being equipped with a series of different concentration known are also measured its density, obtain the typical curve that concerns between halide salt solution concentration and the density, calculate the concentration of said solution according to the densitometer of solution described in typical curve and the step a;

Be linear relationship between the concentration of said solution and the density, concrete relational expression parameter decides according to different solutes:

ω _Sol=a* ρ _Sol+ b (3), wherein, ρ _SolBy the density of survey solution, ω _SolBy the concentration of survey solution, a, b are the unknown constants by the decision of halide salt kind;

C, calculate the concentration of liquid phase in the said slurry according to halide salt hydrate crystal phasor and said slurry temperature; In stabilising system, liquid phase is in state of saturation in the slurry, just can obtain the concentration of liquid phase in the slurry according to slurry temperature and phasor;

D, calculate the concentration of said slurry according to the concentration of liquid phase in the said slurry that obtains among the concentration of the said solution that obtains among the step b and the step c.。

Preferably, according to the principle of mass conservation, through calculating, therefore, the calculated relationship among the above-mentioned steps d is slurry concentration by the massfraction of halide salt in the concentration of melting liquid phase in gained solution concentration, the slurry fully, the hydrate crystal:

Wherein, ω _SolBe the concentration that said slurry melts gained solution fully, ω is the concentration of said slurry, ω _LiqBe the concentration of liquid phase in the said slurry, its value is calculated by phasor and slurry temperature, ω _HBe the mass fraction of halide salt in the said halide salt hydrate crystal, its value is by halide salt kind and hydration number decision.

Preferably, said halide salt is a TBAB.

Compared with prior art, the invention has the beneficial effects as follows: can only carry out the measurement of slurry concentration by cheap density bottle, thermometer, balance, measuring principle is simple to guarantee higher measuring accuracy again simultaneously.

Description of drawings

Fig. 1 is the synoptic diagram of the density bottle of the subsidiary thermometer of expression, wherein: 1. density bottle, 2. grournd glass lid, 3. thermometer;

Fig. 2 is that expression distilled water density is with temperature changing curve diagram;

Fig. 3 is a graph of relation between TBAB solution concentration and the density;

Fig. 4 is a TBAB hydrate crystal phasor;

Fig. 5 be in the storage tank that measures TBAB hydrate slurry bulk concentration with the height change curve.

Embodiment

Below in conjunction with accompanying drawing embodiments of the invention are elaborated: present embodiment provided detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment being to implement under the prerequisite with technical scheme of the present invention.

Embodiment 1

In adopting the chilling air conditioning system of TBAB hydrate slurry as cool storage material; Because TBAB hydrate crystal density is greater than the tetrabutyl phosphonium bromide ammonium salt solution; Sedimentation phenomenon can take place in the storage tank slurry that therefore is used for storing slurry; In order to understand that slurry concentration distributes in the storage tank, can adopt method provided by the invention to measure.Concrete steps are following:

A, the temperature of the TBAB hydrate slurry that is in steady state (SS) is measured, taken out an amount of said slurry then, it is heated it is melted fully be solution, utilize the density bottle method to measure the density p of said solution under the uniform temperature _Sol

The synoptic diagram of density bottle is as shown in Figure 1, and the temperature of the slurry in the density bottle 1 records through thermometer 3, and the volume of density bottle 1 can be demarcated by the distilled water of known density:

$V=\frac{m_1-{\mathrm{<figure-callout\; id="0"\; label="m"\; filenames="HDA0000139697780000022.png,HDA0000139697780000031.png"\; state="\{\{state\}\}">m</figure-callout>}}_0}{{\mathrm{\&rho;}}_{H_{2}O}}---\left(1\right)$

The density of the solution of surveying can be calculated by formula (2):

${\mathrm{\&rho;}}_{\mathrm{sol}}=\frac{m_2-m_0}{V}---\left(2\right)$

In formula (1), (2), V is the density bottle volume, m ₁For filling the density bottle quality of distilled water, m ₀The quality of empty density bottle, m ₂For filling with the density bottle quality of solution, ρ _SolBy the density of survey solution,

For its value of the density of distilled water by the decision of distilled water temperature, can get according to Fig. 2, measure temperature in the present embodiment and be controlled at 20 ℃, so ${\mathrm{\&rho;}}_{H_{2}O}=0.9982323g/{\mathrm{<figure-callout\; id="3"\; label="Cm"\; filenames="HDA0000139697780000021.png,HDA0000139697780000022.png"\; state="\{\{state\}\}">Cm</figure-callout>}}^3;$

B, the TBAB standard solution through under said uniform temperature, being equipped with a series of different concentration known are also measured its density; Obtain the typical curve that concerns between TBAB solution concentration and the density, the density p of melting gained solution fully according to slurry among typical curve and the step a _SolCalculate the concentration of this solution; Fig. 3 is a graph of relation between TBAB solution concentration and the density, can be known by Fig. 3, and TBAB solution concentration and density relations are suc as formula (5):

ω _sol＝10.405*ρ _sol-10.372(5)；

According to formula (5), calculate the concentration ω of said solution _Sol

C, calculate the concentration of liquid phase in the said slurry according to TBAB hydrate crystal phasor and said slurry temperature; In stabilising system, liquid phase is in state of saturation in the slurry, just can obtain the concentration ω of liquid phase in the slurry according to slurry temperature and phasor _Liqω _LiqCan obtain according to phasor shown in Figure 4, suc as formula (6):

ω _Liq=(1.1430+0.52153*T+0.24644*T ²-0.03307*T ³+ 0.00241*T ⁴)/100 (6), wherein T is the temperature of slurry;

D, according to the concentration ω of the said solution that obtains among the step b _SolAnd the concentration ω of liquid phase in the said slurry that obtains among the step c _LiqCalculate the concentration ω of said slurry; According to the principle of mass conservation, the massfraction of halide salt is through calculating in liquid concentration, the hydrate crystal in gained solution concentration, the slurry by melting fully for slurry concentration, and its calculation relational expression is: $\mathrm{\&omega;}=\frac{{\mathrm{\&omega;}}_{\mathrm{Sol}}-{\mathrm{\&omega;}}_{\mathrm{Liq}}}{{\mathrm{\&omega;}}_H-{\mathrm{\&omega;}}_{\mathrm{Liq}}}---\left(4\right),$

Wherein, ω _HValue is tried to achieve according to the chemical formula of TBAB hydrate crystal, and its value is 0.32, and with formula (5), (6) substitution formula (4), the computing formula that obtains present embodiment TBAB hydrate slurry bulk concentration is following:

$\mathrm{\&omega;}=\frac{10.405*{\mathrm{\&rho;}}_{\mathrm{sol}}-(0.52153*T+0.24644*T^2-0.03307*{\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="HDA0000139697780000021.png,HDA0000139697780000022.png"\; state="\{\{state\}\}">T</figure-callout>}}^3+0.00241*T^4)/100-10.383}{0.30857-(0.52153*T+0.24644*T^2-0.03307*{\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="HDA0000139697780000021.png,HDA0000139697780000022.png"\; state="\{\{state\}\}">T</figure-callout>}}^3+0.00241*T^4)/100}$

Formula can be known thus, only need record the solution density ρ that slurry melts gained fully _SolAnd slurry temperature T just can calculate slurry concentration.

Measure the TBAB hydrate slurry bulk concentration of differing heights in the storage tank in the present embodiment and be drawn as curve map; As shown in Figure 5, can know by Fig. 5: low highly more, just more near tank bottom; TBAB hydrate slurry bulk concentration is high more; Reason is that the density of TBAB hydrate crystal is bigger than the density of TBAB hydrate slurry, so the downward sedimentation of TBAB hydrate crystal meeting increases the bottom slurry concentration.

Claims (3)

1. the measuring method of a halide salt hydrate slurry bulk concentration is characterized in that, comprises the steps:

A, the temperature of the said slurry that is in steady state (SS) is measured, taken out said slurry afterwards, heating melts it to be solution, to utilize the density bottle method to measure the density of said solution fully;

The typical curve that concerns between b, preparation halide salt solution concentration and the density is calculated the concentration of said solution according to the densitometer of solution described in typical curve and the step a;

C, calculate the concentration of liquid phase in the said slurry according to halide salt hydrate crystal phasor and said slurry temperature;

D, calculate the concentration of said slurry according to the concentration of liquid phase in the said slurry that obtains among the concentration of the said solution that obtains among the step b, the step c.

2. the measuring method of halide salt hydrate slurry bulk concentration according to claim 1 is characterized in that, the calculated relationship in the said steps d is:

Wherein, ω _SolBe the concentration that said slurry melts gained solution fully, ω is the concentration of said slurry, ω _LiqBe the concentration of liquid phase in the said slurry, ω _HMass fraction for halide salt in the said halide salt hydrate crystal.

3. the measuring method of hydrate slurry bulk concentration according to claim 1 and 2 is characterized in that, said halide salt is a TBAB.

Images