JP2879295B2 - Ice concentration measurement method in ice slurry - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the concentration of ice in an ice slurry, and more particularly to a method for measuring the concentration of ice in an ice slurry which is suitable for transferring cold heat as an ice slurry in district heating and cooling. .

[0002]

2. Description of the Related Art Heretofore, there has been known a so-called district heating and cooling system in which a heat source obtained by a cooling and heating device arranged in an energy center is transferred to a heat source center and supplied to a large number of customers. In this district cooling and heating, hot water or steam is used as a heat source for heating, while cold water is usually used as a heat source for cooling. And the cold water used as a heat source for cooling supplies the cold water of about 7 ° C. obtained by the cooling and heating device to the heat exchanger by a pump,
The cooling water of about 13 ° C. heated by the heat exchanger is collected in a cooling and heating device.

[0003] In such a conventional method of transporting heat in a district heating and cooling system, since the temperature difference between cold water and water heated by heat exchange is not sufficient, the diameter of the transport pipe may be 1 m in some cases. In this case, the pipe diameter and the cost of the pipework for the foundation work are high. For this reason, it is conceivable to use an ice slurry for the cold heat transfer method. In this case, the concentration of ice in the ice slurry (IPF = Ice Packin)
g Factor) increases, the viscosity increases.
When the PF is 30% or more, there is a problem that the transportation efficiency of the slurry pump is deteriorated or the transportation becomes impossible.

In order to solve such a problem, in order to keep the concentration of ice in the ice slurry at a substantially predetermined value, the IPF
Need to be measured. In district heating and cooling, ice slurry is produced using nighttime electric power, and this ice slurry is stored in a heat storage tank. In this case, in order to control the amount of ice introduced into the heat storage tank, This IPF needs to be measured.

Various conventional methods have been proposed for measuring the IPF, such as a method based on the amount of ice adhering to the heat transfer tube, a method using the dielectric constant of the heat storage material, and a method using the transmittance of ultrasonic waves. ing.

[0006]

However, the conventional method for measuring ice concentration in ice slurry as described above is a method for determining the amount of ice in a tank, and therefore cannot measure the ice concentration during transportation. This was extremely inconvenient to apply during the process.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and comprises a mixing vessel having a temperature sensor and a differential pressure transmitter, and a thermostat for storing heated water. A first means for calculating the calorific value of the heating water by supplying a signal from the temperature sensor and the differential pressure transmitter to the processing device after supplying the heating water to the mixing container, and After the ice slurry is supplied into the mixing vessel and mixed with the heated water to form a mixed water, the signals of the temperature sensor and the differential pressure transmitter are input to the arithmetic device to calculate the calorific value of the mixed water. It is an object of the present invention to provide a method for measuring the ice concentration in an ice slurry, comprising: means and a third means for calculating the ice concentration in the ice slurry based on the heat amount of the heating water and the heat amount of the mixed water.

In other words, according to the present invention, the heated brine is charged into a mixing vessel capable of measuring the weight and temperature of the charged liquid, and the ice slurry is mixed and stirred into the brine, and the weight and temperature of the liquid thereafter are adjusted. From the change, the ice concentration in the ice slurry is measured.

[0009]

In the method for measuring the ice concentration in an ice slurry according to the present invention, heated water (heated brine) heated to 50 to 80 ° C. in a thermostat is supplied to a mixing vessel and stirred. Then, the temperature is detected by the temperature sensor, and the amount of the heated water is detected by the differential pressure transmitter, and the signal is input to the arithmetic unit to calculate the amount of heat.

[0010] Thereafter, the ice slurry is supplied from the sampling line to the mixing vessel, where it is stirred and mixed to form mixed water in which ice particles are melted. The temperature of the mixed water decreases while absorbing the latent heat of ice (that is, 80 cal). The temperature of the lowered mixed water is detected by a temperature sensor, and the amount of supplied ice slurry and heated water is detected by a differential pressure transmitter.
The signal is input to an arithmetic unit to calculate the calorific value of the mixed water. Then, the ice concentration in the supplied ice slurry is measured based on the calorific value of the mixed water and the calorific value of the heating water.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method for measuring the ice concentration in an ice slurry according to the present invention will be described below with reference to FIGS. FIG. 1 shows a system diagram of a measuring device used when implementing the method for measuring the ice concentration in an ice slurry according to the present invention. Ice slurry produced by the ice slurry making machine 1 is supplied to the ice slurry tank 3 with a stirrer 2 through line L _1, not shown through the ice slurry transport line 5 by slurry pump 4 from thisゝstorage tank or heat It is supplied to the exchanger.

Reference numeral 6 denotes an elongated cylindrical mixing vessel provided with a stirrer 19 in the center, and a temperature sensor 7 and a differential pressure transmitter 8 are provided in the middle of the mixing vessel, respectively. Sampling line 10 having solenoid valve 9
And the ice slurry is supplied at a predetermined timing. 11 is a thermostat having a heating means,
The thermostatic chamber 11 and the mixing vessel 6 are connected at the upper part by a heating water supply line 14 having an electromagnetic valve 12 and a pump 13. The lower part is connected by a return line 17 having a pump 15 and an electromagnetic valve 16. An overflow line 18 is connected to the thermostatic bath 11, and the overflowed brine is returned to the ice slurry bath 3.

[0013] 20 is an arithmetic unit signal V ₂ of signal V ₁ and the differential pressure transmitter 8 of the temperature sensor 7 is input, 21 respectively control signal to the electromagnetic valve 12,16,9, pumps 13, 15 and an agitator 19 a timer for outputting V ₃ ~V _8. With reference to the block diagram of FIG. 2, a description will be given of a case where the measurement apparatus having the above-described configuration measures the ice concentration of the ice slurry being transported in the ice slurry transport line 5.

When a start command S is given to the timer 21, control signals V _{3 to} V ₅ are issued, the pump 13 and the stirrer 19 are started, the solenoid valve 12 is opened, and the constant temperature in the constant temperature bath 11 is maintained. The heated water is supplied to the mixing vessel 6 through the heated water supply line 14 until at least a water surface is located above the temperature sensor 7. Thereafter, the signals V ₃ and V ₄ are cut off, the pump 13 stops, and the solenoid valve 12 closes.

Then, the heated water supplied into the mixing vessel 6 is stirred by the stirrer 19 to measure the temperature. After the agitator 19 signal V ₅ is interrupted then stops, the detected temperature and pressure of the heating water by the temperature sensor 7 and the differential pressure transmitter 8, the signal V _1, V ₂ are inputted to the arithmetic unit 20 , temperature and supply quantity of heated water obtained by thisゝfrom signals V ₁ and V ₂ are computed.

Next, the control signals V ₆ ,
V ₅ is outputted, is the electromagnetic valve 9 is opened with a stirrer 19 is activated, ice slurry flowing through the ice slurry transfer line 5 is supplied to the mixing vessel 6 through a sampling line 10. The ice slurry is blocking the control signal V ₆ and supplied in a predetermined amount, the electromagnetic valve 9 is closed. Mixing container 6
The ice slurry supplied to the inside is mixed and stirred by the stirrer 19, and the ice particles are melted to form low-temperature mixed water. After a mixture water, agitator 19 is cut off the control signal V ₅ is stopped.

Thereafter, the temperature of the mixed water is detected by the temperature sensor 7 and the pressure is detected by the differential pressure signal device 8, respectively.
The signals V ₁ and V ₂ are input to the arithmetic unit 20 and the amount of mixed water is calculated. Then, the calorific value of the mixed water in the mixing container 6 and the calorific value of the heating water supplied to the mixing container 6 in advance are calculated by the following formula to calculate the ice concentration in the ice slurry.

IPF = Cp × G ₁ (T ₁ −T ₂ ) −Cp
(G ₂ −G ₁ ) (T ₂ −T ₃ ) / G ₂ × 100 Cp: Specific heat of liquid Kcal / Kg ° C. G ₁ : Volume of heated water (K
g) T ₁ : Temperature of heated water (° C) G ₂ : Volume of mixed water (K
g) T ₂ : Temperature of mixed water (° C.) T ₃ : Temperature of ice slurry (° C.) (O ° C. for ice) After the ice concentration is measured in this way, the control signal V ₇ , V ₈ is output, the solenoid valve 16 is opened, and the pump 15 is started, and the mixed water in the mixing vessel 6 is collected from the return line 17 into the thermostat 11.

When the amount of the heated water in the thermostatic bath 11 exceeds a predetermined amount, the ice slurry bath 3 is passed through an overflow line 18.
Refluxed inside. The measurement of the ice concentration is repeated, for example, every minute or every few minutes. The ice concentration in the ice slurry transported by the ice slurry transport line 5 is measured, and the ice slurry is stored in the heat storage tank and the ice slurry is transported. Management takes place.

[0020]

As is clear from the above description, according to the method for measuring the ice concentration in the ice slurry according to the present invention, the heating water and the ice slurry are mixed, and the ice concentration of the ice slurry is reduced by lowering the temperature in that case. There is an effect that it is easy to automate by simple means of measuring, and it is possible to perform accurate measurement with a simple device.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of a method for measuring ice concentration in an ice slurry according to the present invention.

FIG. 2 is a block diagram showing an operation procedure of an ice concentration measurement method in an ice slurry according to the present invention.

[Explanation of symbols]

1 ice slurry making machine 2,19 stirrer 3
Ice slurry tank 4, 3, 15 Pump 5 Ice slurry transport line
6 Mixing container 7 Temperature sensor 8 Differential pressure transmitter 9, 12, 1
6 Solenoid valve 10 Sampling line 11 Constant temperature bath 14
Heated water supply line 17 Return line 18 Overflow line
20 arithmetic unit 21 timer

──────────────────────────────────────────────────の Continuing from the front page (72) Keiichi Watanabe, Inventor Keiichi Watanabe, Chiba Pref. (56) References JP-A-5-340903 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01N 25/00-25/72 G01K 17/00

Claims (1)

(57) [Claims] 1. A mixing container having a temperature sensor and a differential pressure transmitter, a constant temperature bath for storing heated water, and an arithmetic unit, wherein after supplying the heated water to the mixing container, the temperature sensor and the differential pressure A first means for inputting a signal from a transmitter to the arithmetic unit to calculate the calorific value of the heating water; and supplying ice slurry into the mixing vessel and mixing the heating water to form a mixed water, A second means for inputting a signal from a sensor and a differential pressure transmitter to the arithmetic unit to calculate a calorific value of the mixed water; and calculating an ice concentration in the ice slurry from a caloric value of the heating water and a calorific value of the mixed water. A method for measuring ice concentration in an ice slurry according to a third means.