JPH07104086B2 - Control method of watering interval in layered ice making method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to meteorological data of a specific area by using, for example, an integrated value of temperature-wind speed required for producing ice having a unit thickness when making ice in an ice pond used for storing agricultural products. The present invention relates to a method for controlling a watering interval in a laminated ice making method that enables efficient ice making by estimating the thickness of ice that can be produced at that location and performing ice making control.

[0002]

2. Description of the Related Art In sprinkling control in a conventionally well-known layered ice production method, the cumulative coldness required for freezing a water film having a unit thickness (a value obtained by multiplying a temperature difference between a negative temperature and 0 ° C. by time, a unit Kh: Kelvin hour) is known, and the cumulative cold degree corresponding to one spray thickness is set, and the point when the cumulative cold degree after sprinkling reaches the set value is the time for complete freezing of the water film, and the next sprinkling is performed. The watering interval is controlled.

[0003]

Actually, the freezing speed of the water film is greatly influenced by the wind speed on the ice surface in addition to the accumulated coldness. That is, when the outside temperature is the same, the higher the wind speed, the faster the freezing. Therefore, in the above conventional ice making method, when the wind speed is low, unfrozen ice is likely to occur, and when the wind speed is high, there is a tendency that the next watering is not performed promptly even if the water film is completely frozen. There is a problem that the efficiency of using cold energy in the surrounding environment is reduced. The present invention aims to solve the above problems.

[0004]

In order to achieve the above-mentioned object, the present invention is a laminated ice making method in which water is repeatedly sprinkled and frozen on a thin water film by frequent intermittent water sprinkling to perform water sprinkling for a certain period of time. , The water film thickness is estimated from the amount of water sprayed and the watering area, and the temperature-wind speed integrated value required to freeze the water film is set, and the temperature and wind speed are measured at regular intervals to calculate the temperature-wind speed integrated value. This temperature-the integrated value of wind speed is the above temperature-
Air temperature and wind speed measurements are repeated until the set value of the integrated wind speed is reached, and the point when the integrated value of temperature-wind speed reaches the above set value is regarded as the time for complete freezing of the water film, and the cycle of returning to water sprinkling for the above fixed time is repeated. It is characterized by performing ice making.

[0005]

According to the above method, the present invention accurately estimates the time of complete freezing of the water film when the environmental conditions (temperature and wind speed) fluctuate, and watering is performed so that the ice making thickness per unit time becomes the largest. In order to automatically control the interval, the complete freezing time of the water film is estimated by evaluating the contribution rate of the accumulated cold degree to freezing, taking into consideration the influence of wind speed, instead of the conventional control using only the accumulated cold degree. Then, the watering interval is determined and the ice making is performed efficiently.

[0006]

First, the principle of the present invention will be described. Since it is actually impossible to continuously measure the wind speed on the ice surface, a wind speed of several meters above the ground near the place where ice is made is adopted. FIG. 1 shows the effect of wind speed on the freezing speed of a water film. From this figure, for example, when the wind speed is 2 m / s, the cumulative cold degree due to freezing of the water film is about one-third of that when there is no wind.
You can see that Also, the relationship between the two is not linear, and the cumulative cold degree required for freezing increases rapidly as the wind speed decreases.

Assuming that the wind velocity is X, the integrated coldness required for freezing of the water film is Y, and f is a function symbol, the relation between them is Y = f (X) ... (1) Shown. In order to utilize this relationship for actual ice making control, the following method is taken. Y at X = 0
Is defined as Y0, and the ratio of the value of Y at any X and Y0 is defined as the "cold evaluation value". That is, coldness evaluation value = f (X) / Y0 (2) The coldness evaluation value shows how much the outside air temperature at each wind speed contributes to the freezing of the water film as compared to when there is no wind. . When calculating the outside air temperature and the wind speed at regular time intervals (for example, one minute intervals), the "temperature-wind speed integrated value" is defined as follows. Temperature-wind speed integrated value = Σ {(outside air temperature x measurement interval) x coldness evaluation value} (3) Since the (outside air temperature x measurement interval) part of this equation is the accumulated coldness, the temperature-wind speed integrated value The value is equal to the accumulated cold degree when there is no wind, and the higher the wind speed, the larger the evaluated value of the accumulated cold degree. The control of the watering interval in actual ice making is automatically performed by incorporating the following procedure into a computer program. Water for a certain period of time. The water film thickness is estimated from the amount of water sprayed and the area of water sprayed. Set the temperature-air velocity integrated value required to freeze the water film. The air temperature and the wind speed are measured at regular intervals, and the temperature-wind speed integrated value is calculated by the above equations (2) and (3). The above is repeated until the temperature-air velocity integrated value reaches the above set value. The time point when the temperature-wind velocity integrated value reaches the above-mentioned set value is regarded as the complete freezing time of the water film, and the process returns to the above.

Next, regarding the embodiment based on the above principle,
A specific description will be given with reference to the accompanying drawings. FIG. 2 shows an ice making system in an ice pond, and reference numeral 1 is an ice pond having a size of 10 m long × 14 m wide × 2 m deep. On this ice pond 1, a water sprinkling pipe 3 having a plurality of (two in this embodiment) spraying nozzles 2 is arranged, and the water in the water storage tank 5 is supplied to this water sprinkling pipe 3 via a pump 4. Are connected to each other. Well water 6 is pumped up and supplied to the water tank 5 by a pump (not shown). On the other hand, an anemometer 7 and an air temperature sensor 8 are installed at a position several meters above the ground in the vicinity of the ice pond 1, and the measurement data from the anemometer 7 and the air temperature sensor 8 are sent to a data logger 9 and recorded therein. A personal computer (hereinafter referred to as a personal computer) 10 is connected to the data logger 9, and a relay unit 11 is connected to the personal computer 10 so that the relay unit 11 operates the pump 4.
Connected to control deactivation.

In the ice pond 1 of the above embodiment,
When ice making is performed, the pump 4 is operated via the relay unit 11 in response to a command from the personal computer 10, the water in the water storage tank 5 is pressure-fed to the water spray pipe 3, and the spray nozzle 2 is placed on the upper surface of the ice pond 1. The operation of freezing the water film sprinkled to a thickness of 0.2 to 0.4 mm at a time is repeated. In the personal computer 10, the measurement data from the anemometer 7 and the temperature sensor 8 are input via the data logger 9, and based on the data,
The temperature-wind velocity integrated coldness is calculated every 30 seconds according to the program, and the operation interval of the pump 4 is controlled. In other words, by utilizing the relationship between the temperature / wind speed and the freezing speed of the water film, the contribution rate of the accumulated cold degree to the freezing rate is calculated from the wind speed, and the accumulated cold degree is evaluated and converted into the temperature-wind speed integrated value. Then, the temperature-wind velocity integrated value is used to estimate the time of complete freezing of the water film to perform ice making.

The graph of FIG. 3 shows a case where the watering interval is controlled using the temperature-wind speed integrated value (the present invention) and a case where only the integrated cold degree is used (conventional) under the same outdoor environment conditions. It shows the change in the production thickness of ice. In this graph, the shaded area represents the increase in the ice-making efficiency when the temperature-wind speed integrated value is used, and the ice production rate is higher than the control using the integrated coldness, that is, the energy utilization efficiency is high, and the final It can be seen that the thickness of the ice that will be formed will also increase significantly.

[0011]

As described above, according to the method of controlling the watering interval in the laminated ice making method of the present invention, the following effects can be obtained. The temperature-wind speed integrated value was used to estimate the time for complete freezing of the water film to perform ice making.Therefore, the lower the air temperature and the higher the wind speed, the shorter the watering interval and the ice production rate. Get faster Therefore, as in the conventional method, the lower the temperature is, the shorter the sprinkling interval is, and the problem that unfrozen ice occurs or wasteful supercooling of completely frozen ice occurs due to the size of the wind speed is certain. Will be resolved.

[0012] Further, ice produced under any conditions of temperature and wind speed becomes completely frozen ice, and energy utilization efficiency is improved, and for example, an inexpensive cooling heat source for agricultural product storage can be secured. .

Further, since it is possible to estimate the thickness of ice that can be produced at a place from the meteorological data of a specific area by using the integrated value of temperature-wind speed required for producing ice having a unit thickness, it is useful for designing an ice pond. You can Further, the method of the present invention, in various fields other than agricultural product storage, whether indoors or outdoors as an energy-saving technology by utilizing ice cold heat,
It can contribute to the efficiency of stacked ice production.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between wind speed and cumulative coldness required for freezing a water film.

FIG. 2 is a schematic side view of an embodiment of the method of the present invention.

FIG. 3 is a graph showing a comparison of ice-making thickness when temperature-wind speed integrated value and integrated cold degree are used.

[Explanation of symbols]

 1 Ice Pond 2 Spray Nozzle 3 Sprinkler Pipe 4 Pump 5 Water Tank 6 Well Water 7 Anemometer 8 Air Temperature Sensor 9 Data Logger 10 PC 11 Relay Unit

Claims (1)

[Claims] 1. In a layered ice making method in which thin water film is repeatedly sprinkled and frozen to make ice by frequent intermittent sprinkling, water is sprinkled for a certain period of time, and the water film thickness is calculated from the sprinkling amount and the sprinkling area.
The wind temperature and the integrated value of temperature and wind speed required to freeze the water film.
Temperature and wind speed at regular intervals,
Calculate the integrated value of wind speed, and this temperature-integrated value of wind speed is the above temperature.
− Measure the temperature and wind speed until the set value of the integrated wind speed is reached.
Repeatedly, when the temperature-air velocity integrated value reaches the set value above
Is regarded as the time of complete freezing of the water film, and water is sprinkled for the above fixed time.
A method for controlling a watering interval in a laminated ice-making method, characterized in that a return cycle is repeated to perform ice-making.