JPH04313658A - Ice regenerator - Google Patents

Abstract

PURPOSE:To improve an efficiency of a refrigerator, a charging ratio of ice, performance of ice thawing by supplying fluorinated liquid and water to an icemaker, precipitating ice by contact heat exchanging, supplying the liquid, the water and the ice to a separation tank, and supplying the separated water, ice to an ice water tank. CONSTITUTION:Water 7 of an ice water tank 3 and fluorinated liquid 6 of an ice water separation tank 2 are mixed in a porous tube 10 of a double tube type icemaker 1 by circulation pumps 4, 5, partial water is converted to ice by direct contact heat exchanging as mixed state flow of the fluorinated liquid, water and ice, and ice 8 and other liquids are separated by a demister 9 of the tank 2. The fluorinated liquid 6 and the ice are separated by a specific weight difference, the liquid 6 is precipitated, and the water 7 is floated. Since the water 7 is output from the tank 3 and input to the tank 2, the liquid surface of the tank 2 rises, and the ice 8 and the water 7 floated at the upper part flow to the tank 3 over a band between the tanks 2 and 3. Since only the water 7 and the ice exist in the tank 3, charging ratio of the ice can be enhanced, and the ice 8 is in a sherbet state to improve performance of ice thawing.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice heat storage device for air conditioning.

0002

[Prior Art] In order to reduce the demand for electricity for cooling, which is concentrated during the day, an air conditioning system having a conventional ice heat storage device has the following functions:
It uses cheap late-night electricity to reduce the load on heat source equipment, and is applied to relatively large-capacity air conditioning systems such as building air conditioning and district heat supply. There are two methods for producing ice in this ice heat storage device: an indirect heat exchange method and a direct heat exchange method.

By the way, the former indirect heat exchange method uses antifreeze such as ethylene glycol or Freon as a cooling medium to generate ice on the outside or inside of the ice-making heat transfer tube installed in the ice heat storage tank. When ice is formed on the wall of a heat transfer tube for ice making, as the thickness of the ice increases, the thermal conductivity of the ice itself decreases, so the rate of ice formation decreases due to the decrease in heat transfer from the cooling medium to the water. This slows down the cooling process and reduces the efficiency of the refrigerator that cools the cooling medium.

[0004] Therefore, when heat transfer tubes are placed in an ice heat storage tank, ice forms on the outside of the heat transfer tubes, so if an attempt is made to increase the number of heat transfer tubes to improve the efficiency of the ice heat storage tank, As the number of heat exchanger tubes increases, the occupation rate of the heat exchanger tubes in the water tank increases, and the filling rate of ice decreases. On the other hand, even if the number of heat exchanger tubes is reduced, if the thickness of ice on the heat exchanger tubes increases,
Not only does the rate of ice formation slow down, but when the ice melts, some parts of the ice are easily melted, making the ice thickness uneven as a whole, reducing efficiency. Because icing starts from the icing part, the thicker parts become even thicker, and eventually the ice comes into contact with each other, which can lead to accidents such as bending or damage of the heat exchanger tubes.

[0005] Also, as a type of this indirect heat exchange method,
Ice is cooled through heat transfer tubes for ice making, and there is a method that uses continuous flow supercooled water that takes advantage of the phenomenon that if water is selected as the liquid to be cooled and the water is allowed to flow at a certain flow rate, it will not freeze even at temperatures below 0°C. . In this method, when the continuous flow of supercooled water is returned to the heat storage tank, a collision plate is installed to eliminate the kinetic energy, and some of the supercooled water is precipitated as ice particles and stored in the heat storage tank. ice can be stored in a thermal storage tank. Therefore, since there are only ice particles and water in the heat storage water tank, the filling rate of ice is high.

However, in the process of creating a continuous flow of supercooled water, it is necessary to flow the water without stagnation, so only straight pipes can be used. Since a cooling section is required, the length of the straight pipe must be increased, and the supercooler itself becomes long. Furthermore, as the flow rate of supercooled water changes, it is difficult to control its temperature, and in reality, using a refrigerant as a cooling liquid may cause cooling or blockage in the pipes due to evaporative heat transfer. Brine must be used as the liquid, and the coefficient of performance of the refrigerator is not good. Moreover, even the presence of minute particles in this supercooled water causes freezing, which poses a problem in the cleanliness of the circulating water.

On the other hand, the latter direct heat exchange method generates ice by directly circulating a low-temperature cooling medium into the ice storage tank. Although the efficiency of the cooling medium improves, since the cooling medium gas and lubricating oil for the compressor enter the water, the water and the cooling medium gas may react and generate corrosive gas, or the physical properties of the cooling medium itself may change. This phenomenon occurs. Furthermore, since the lubricating oil contained in the refrigerant cannot actually be mixed into the water tank, it is necessary to separate the refrigerant and lubricating oil, and conversely, the water contained in the refrigerant gas that evaporates in the water tank is Moisture removal from the refrigerant gas is also necessary as it causes adverse effects within the compressor. Furthermore, the ice heat storage tank, which is also an evaporator, becomes a high-pressure container, so it is not suitable for upsizing.

[0008]

As mentioned above, methods for producing ice heat storage are broadly classified into direct heat exchange methods and indirect heat exchange methods, each of which has the following drawbacks. In other words, (1) The method of making and depositing ice on the surface of heat transfer tubes causes a decrease in the coefficient of performance of the refrigerator, a low ice filling rate, and poor ice-melting performance.
There are drawbacks such as damage to heat exchanger tubes. (2) A method using a continuous flow of supercooled water has drawbacks such as the length of the supercooler, the cleanliness of the supercooled water, and the difficulty in controlling the temperature of the supercooled water. (3) The method of directly blowing refrigerant liquid (gas) into water has drawbacks such as the generation of corrosive gas, the necessity of separating oil and water, and the need for a high-pressure container.

The present invention was made in order to solve the above-mentioned drawbacks, and its purpose is to improve the efficiency and ice filling rate of the refrigerator, as well as the ice-melting performance, and also to avoid generating corrosive gases. The object of the present invention is to provide a new ice heat storage device in which the physical properties of the refrigerant itself do not change. [Structure of the invention]

0010

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an ice maker, an ice maker whose specific weight is at least 1.5 times that of water,
It consists of Fluorinert liquid, which is a cooling medium with a freezing point of -20°C or less and is insoluble in water, a separation tank that separates and stores Fluorinert liquid and water, and an ice water tank that stores water and ice. Water is supplied to the ice maker by a pump to precipitate ice by direct contact heat exchange, and the Fluorinert liquid, water and ice are supplied to the separation tank, and the water and ice separated in the separation tank are transferred to the ice water tank. It is characterized in that it is configured to supply

[0011]

[Action] Fluorinert liquid used as a cooling medium is
It is a colorless, transparent, odorless, and inert liquid, and has a completely fluorinated structure. It is a combination of carbon atoms C and fluorine atoms F, and the boiling point and freezing point differ depending on the number of bonds. However, most of them have a freezing point of -20°C or lower. Its specific weight is more than 1.7 times that of water at around 0℃, about twice that of ice, and its solubility in water is 7.
Since the amount is quite low at 2 ppm, even if it is mixed with water, it will completely separate and the Fluorinert solution will precipitate and the water will float, so strong stirring is required to mix the two.

[0012] Utilizing the characteristics of this cooling medium (Florinat liquid), by mixing water and Fluorinert liquid below 0°C in a double pipe ice maker, the Fluorinert liquid, water,
It flows as a multiphase flow with ice, floats the ice to the surface in a separation tank to separate the three types of media, and stores this ice in a separate storage tank as an ice water tank. It is possible to realize an ice heat storage tank with a high efficiency. In addition, the ice maker is of a double-tube type, with water (or 0°C
Fluorinert solution) is passed between the outer tube and the inner tube at 0℃.
By supplying the following Fluorinert liquid and supplying this Fluorinert liquid at a temperature of 0°C or less through a large number of small holes provided in the inner tube, water and ice in the multiphase flow are prevented from adhering to the inner wall of the inner tube. A stable multiphase flow of Fluorinert liquid, water, and ice can flow.

[0013]

[Embodiments] Hereinafter, embodiments of the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. As shown in the figure, the ice heat storage device mainly includes an ice maker 1, an ice water separation tank 2, an ice water tank 3, and a refrigerator 11. In the ice-water separation tank 2, Fluorinert liquid 6 and water 7 are separated and stored, and in the ice-water tank 3, water 7 and ice 8 are stored. The ice maker 1 is of a double tube type, and the inner tube is a perforated tube 10 with a large number of small holes. The Fluorinert liquid 6 is extracted from the lower part of the ice-water separation tank 2 and is supplied to the ice maker 1 through the refrigerator 11 by the Fluorinert liquid circulation pump 4, and the part of the Fluorinert liquid 6 that is not cooled is passed through the ice maker 1 and the water circulation line. The configuration is such that it is directly supplied to the Further, the Fluorinert liquid 6 that has passed through the refrigerator 11 is supplied from the outside of the outer tube of the ice maker 1, and is supplied into the inner tube through a small hole in the inner tube. Water 7 stored in the ice water tank 3 is supplied into the inner pipe of the ice maker 1 by a water circulation pump 5. In the inner tube of the ice maker 1, water (or a mixture of Fluorinert liquid and water at 0°C or higher) flows from the water supply port 21, and Fluorinert liquid at 0°C or lower flows from the small holes of the porous tube 10, which is the inner tube. Some of the water is converted into ice, which is then dropped and supplied to the ice-water separation tank 2. A demister 9 is installed at the top of the ice-water separation tank 2, which separates the ice 8 from other liquids, water 7, and Fluorinert liquid 6, and sends the ice 8 and water 7 floating at the top over the weir to the ice-water tank. 3.

FIG. 2 is a schematic diagram of the ice maker of the ice heat storage device of FIG. 1, and FIGS. 3(a) and 3(b) are detailed diagrams of the ice maker. As shown in FIG. 2, the ice maker 1 is of a double-tube type, and the inner tube has many small holes and a Fluorinert supply hole 19.
It is a porous pipe 10 provided with. The outer tube is provided with a plurality of nozzles in the longitudinal direction, and has a structure in which the Fluorinert liquid for cooling and the Fluorinert liquid for non-cooling are supplied to the part between the outer tube and the inner tube divided by the partition plate 18. ing. A non-cooling Fluorinert liquid supply section 15 having a non-cooling Fluorinert supply nozzle 17 installed is formed on the upstream side, and a cooling Fluorinert liquid supply section 14 having a cooling Fluorinert supply nozzle 16 installed on the downstream side. The end of the inner tube is connected to the water supply pipe 13, and the non-cooling Fluorinert and water that have entered from the Fluorinert supply hole 19 of the porous pipe 10 flow through the water flow run-up section 12, and are further cooled. It has a structure in which it exchanges heat while being mixed with Fluorinert, and sulfurizes it from the downstream multiphase flow discharge port 22 to the ice-water separation tank 2. Further, as shown in FIG. 3(b), the Fluorinert supply hole 19 leading from the Fluorinert supplying portion to the inside of the inner tube is structured to open toward the tangential direction of the inner tube.

Since the ice heat storage device of this embodiment is constructed as described above, the water 7 in the ice water tank 3 and the Fluorinert liquid 6 in the ice water separation tank 2 are circulated by circulation pumps 4 and 5, respectively, in a double pipe type. Some of the water is mixed in the porous tube 10, which is the inner tube of a certain ice maker 1, and is converted into ice by direct contact heat exchange, which flows as a multiphase flow of Fluorinert liquid, water, and ice.
ice 8 and other liquids are separated using a demister 9. The Fluorinert liquid 6 and water 7 below are naturally separated due to the difference in specific gravity, and the Fluorinert liquid 6 precipitates in the lower part, and the water 7 floats in the upper part. The Fluorinert liquid 6 comes out of the ice-water separation tank 2 and returns to the ice-water separation tank 2, but the water 7 comes out of the ice-water tank 1,
As it returns to the ice-water separation tank 2, the liquid level in the ice-water separation tank 2 rises, and the ice 8 and water 7 floating at the top cross the weir between the ice-water separation tank 2 and the ice-water tank 3 and flow into the ice-water tank. Flows into 3. In this way, the ice 8 can be stably stored in the ice water tank 3.

[0017] Furthermore, the ice maker 1 is of a double-tube type, and small openings 19 are uniformly provided in the connection direction in the inner tube in the longitudinal direction, thereby maintaining the flow in the inner tube in a swirling manner while keeping the temperature below 0°C. Fluorinert liquid is supplied, so a multiphase flow of Fluorinert liquid, water, and ice can be flowed without causing the ice and water precipitated by direct contact heat exchange to adhere to the inner wall of the inner tube and the Fluorinert supply hole 19. All ice can be supplied to the ice-water separation tank 2. A water flow run-up section 12 is provided at the end of the inner pipe to supply Fluorinert at 0°C or higher, and prevent sudden contact between the Fluorinert liquid at 0C or lower and water downstream of the water flow run-up section 12. As a result, granular ice can be deposited stably.

As described above, according to this embodiment, a stable multiphase flow of Fluorinert liquid 6, water 7, and ice 8 can be formed in the double-tube ice maker 1, and granular ice can be precipitated. Therefore, sherbet-like ice can be deposited in the ice-water separation tank 2. Further, since the volume of water in the ice-water separation tank 2 increases, the water above the liquid level and the floating ice can cross the weir between the ice-water tank 3 and accumulate ice 8 in the ice-water tank 3. What enters the ice water tank 3 is only the water at the top of the ice water separation tank 2 and the floating ice, so there is 7 water in the ice water tank 3.
The filling rate of ice in the ice tank 3 can be increased, and the ice 8 in the ice tank 3 is sherbet-like and easily melts. The ice-melting performance is also good because the ice can be easily melted.

Furthermore, since the Fluorinert liquid 6 is directly supplied to the refrigerator, the coefficient of performance of the refrigerator is good. moreover,
Since direct contact heat exchange is performed by mixing Fluorinert liquid 6 and water 7 with forced convection, the heat exchange performance is also very good. Furthermore, since the Fluorinert supply hole 19 is opened in the tangential direction in the inner tube of the ice maker 1, the multiphase flow flows in a swirling flow, and water and ice with small specific weight flow through the center, so that the inner tube wall surface Since water and ice can be prevented from adhering to the tube, there is no blockage of small holes or deformation of the inner tube flow path.

[0020]

[Effects of the Invention] As explained above, the ice heat storage device of the present invention has the following effects.

(1) Due to the forced convection contact mixing of the Fluorinert liquid and water, the heat exchange performance between the Fluorinert liquid and water is high, and since the Fluorinert liquid is directly cooled by the cooling pipe of the refrigerator, the coefficient of performance of the refrigerator is low. expensive. (2) Since granular ice is precipitated in the ice maker, the ice-melting performance is good even if it is deposited in an ice bath. (3) Since the ice water tank itself is the same as a conventional water tank, it has a high ice filling rate and can be easily enlarged. (4) Fluorinert liquid has low volatility and there is always water above the Fluorinert liquid in the ice-water separation tank, so there is no need to replenish it.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 is a schematic diagram of the ice maker shown in FIG. 1.

[Figure 3] Figure 3 (a) is a perspective view of the inner tube of the ice maker, Figure 3 (b)
is a cross-sectional view of the inner tube of the ice maker.

[Explanation of symbols] 1... Ice maker, 2... Ice water separation tank, 3... Ice water tank, 4... Fluorinert circulation pump, 5... Water circulation pump, 6... Fluorinert liquid, 7... Water, 8... Ice, 9... Demister, 10 ... Fluorinert supply porous pipe, 11 ... Refrigerator, 12 ... Water flow run-up section, 1
3... Water supply pipe, 14... Fluorinert supply section for cooling, 15
...Fluorinert supply unit for non-cooling, 16...Fluorinert supply nozzle for cooling, 17...Fluorinert supply nozzle for non-cooling, 18...Fluorinert partition plate for cooling and non-cooling, 19
... Fluorinert supply hole, 20... Fluorinert and water mixed phase flow path, 21... Water supply port, 22... Multiphase flow outlet.

Claims (1)

[Claims] [Claim 1] An ice maker, a Fluorinert liquid which is a cooling medium having a specific weight of at least 1.5 times that of water, a freezing point of -20°C or lower, and insoluble in water, and separating and storing the Fluorinert liquid and water. It consists of a separation tank and an ice water tank that stores water and ice.
The Fluorinert liquid and water are supplied to the ice maker with a pump to precipitate ice by direct contact heat exchange, and the Fluorinert liquid, water and ice are supplied to the separation tank, and the water and ice separated in the separation tank are An ice heat storage device configured to supply ice to the ice water tank.