JPH09126593A - Antifreezing structure of heat exchanger for supercooling water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent freezing from being caused in a heat exchanger for supercooling water by mounting a predetermined length heat insulation member on an inner pipe outer peripheral surface in the vicinity of an outlet of the double pipe structured heat exchanger for supercooling water composed of an outer pipe and an inner pipe. SOLUTION: A heat exchanger 2 is double-structured such that an outer pipe 2a is formed into a spiral shape into which an inner pipe 2b is inserted. Water to be cooled supplied from an ice storage tank flows between the outer pipe 2a and the inner pipe 2b, and a refrigerant supplied from a freezer flows into the inner pipe 2b. An antifreezing structure includes a predetermined length heat insulation member mounted on an outer peripheral surface of the inner pipe 2b, the insulation member using a silicon rubber heat contraction tube or a teflon tube for example. Hereby, in the vicinity of an outlet where the supercooling water is unstable heat exchange between a refrigerant and the water to be cooled is interrupted to avoid a freezing factor, and hence freezing of the heat exchanger is securely prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to production of supercooled water, and more particularly to prevention of freezing of a heat exchanger for supercooled water.

[0002]

2. Description of the Related Art Conventionally, there is an ice storage type cold water device for supplying cold water to an air conditioner, a food cooling device and the like. As shown in FIG. 4, this ice storage type cold water device communicates with an ice storage tank 31 and a supercooled water heat exchanger 32 (hereinafter, referred to as “heat exchanger 32”) by a circulation path 33. At the same time, the heat exchanger 32 and the refrigerator 34 are connected by a refrigerant circulation path 35. This ice storage type cold water storage device stores ice in the ice storage tank 31 by using late-night electric power, which has a low electricity rate, and is installed above the ice storage tank 31 in response to a load demand during operation of a food cooling device or the like. In addition to supplying the deicing water from, cold water is taken out from the lower part.

By the way, the operation of this ice storage type cold water device is as follows.
After the ice storage tank 31 is filled with water, the refrigerator 34 is activated to supply the cooling medium into the heat exchanger 32 for circulation, and at the same time, the cooled water in the ice storage tank 31 is sent to the heat exchanger 32. The heat-exchanged and supercooled water is stored in the ice storage tank 31.
Reflux into. When ice making starts in the ice storage tank 31, the temperature of the water to be cooled, which circulates and flows into the heat exchanger 32, lowers and freezing easily occurs in the heat exchanger 32, and particularly when the water temperature becomes 1 ° C. or less. It often freezes after a short period of operation. Therefore, conventionally, as a countermeasure, a method of worsening the heat insulation of the circulation path 33 between the ice storage tank 31 and the heat exchanger 32, or providing an auxiliary heat exchanger (not shown) for positive heating However, the water temperature at the inlet of the heat exchanger 32 is increased to deal with it, but it has not been possible to completely prevent freezing.

As shown in FIGS. 4 and 5, the heat exchanger 32 has a double pipe structure in which an outer pipe 32a is formed in a spiral shape and an inner pipe 32b is inserted into the outer pipe 32a. Water to be cooled supplied from the ice storage tank 31 flows between the inner pipe 32b and the inner pipe 32b, and a cooling medium supplied from the refrigerator 34 flows into the inner pipe 32b. Therefore, because the structure is such that the water to be cooled is cooled from the outer circumference of the inner pipe 32b to produce supercooled water, freezing in the heat exchanger 32 often occurs in the vicinity of the outlet in many cases, and measures against it are often taken. Is requested. Further, the same problem also occurs when the cooling medium is circulated between the outer pipe 32a and the inner pipe 32b and the water to be cooled is circulated in the inner pipe 32b.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a structure for preventing freezing of a heat exchanger for supercooled water.

[0006]

The present invention has been made to solve the above-mentioned problems, and is a heat exchanger for supercooled water having a double pipe structure including an outer pipe and an inner pipe. In the vicinity of the outlet of the heat exchanger for supercooled water, a heat insulating member of a predetermined length is attached to the outer peripheral surface of the inner pipe.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. The present invention is a heat exchanger for supercooled water (hereinafter referred to as "heat exchanger") applied to an ice storage type cold water device. ), Which is particularly effective for a heat exchanger having a double pipe structure composed of an outer pipe and an inner pipe. The present invention is realized by providing a heat insulating structure near the outlet of the heat exchanger. The supercooled water in the vicinity of the outlet of the heat exchanger is forced to change its distribution mode due to a route change, pipe connection, etc., and the supercooled state thereof becomes unstable accordingly. If a heat exchange action is applied to this unstable supercooled state, the freezing factor will increase. However, in the present invention, the heat exchange to this unstable supercooled portion is shut off. It is characterized by the configuration. That is, this is realized by providing a heat insulating structure near the outlet of the heat exchanger. Specifically, in the vicinity of the outlet of the heat exchanger, the inner pipe has a heat insulating structure over a predetermined length.

[0008] Specifically, the heat insulating structure has a structure in which a heat insulating member of a predetermined length is attached to the outer peripheral surface of the inner pipe near the outlet of the heat exchanger. With this heat insulating member, a freezing factor for an unstable supercooled portion of the supercooled water is avoided, and freezing is reliably prevented. The heat insulating member is made of, for example, a member that effectively blocks a heat exchange action with a liquefied cooling medium (for example, Freon) and is hard to be iced. A tube or a Teflon tube or the like is used.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view showing a configuration of an ice storage type cold water device embodying the present invention, and FIG. 2 is an explanatory view showing a cross section near an outlet of a supercooling water heat exchanger.

In FIG. 1, the ice storage type cold water system comprises a refrigerator 1, a heat exchanger 2 for supercooled water (hereinafter referred to as "heat exchanger 2") and an ice storage tank 3. Refrigerator 1
Is a method in which, for example, a liquefied cooling medium (for example, CFC) is decompressed by the expansion valve 1a, and then the water to be cooled is directly cooled by the latent heat of vaporization of the cooling medium (hereinafter referred to as “refrigerant”) via the heat exchanger 2. Is used. As shown in FIGS. 1 and 2, the heat exchanger 2 has a double pipe structure in which an outer pipe 2a is formed in a spiral shape and an inner pipe 2b is inserted therein, and the outer pipe 2a and the inner pipe 2a Ice storage tank 3 between pipe 2b
The water to be cooled supplied from the refrigerator 1 flows through, and the refrigerant supplied from the refrigerator 1 flows through the inner pipe 2b. Therefore, the water to be cooled is cooled from the outer periphery of the inner pipe 2b to be supercooled water, and the supercooled water is caused to flow into the ice storage tank 3. In this embodiment, the refrigerant is circulated in the inner pipe 2b, but the water to be cooled may be circulated in the inner pipe 2b and the refrigerant may be circulated between the outer pipe 2a and the inner pipe 2b. It is suitable depending on the implementation.

The refrigerator 1 and the inner pipe 2b are connected by a refrigerant supply path 4 via an expansion valve 1a, and
They are connected by a refrigerant circulation path 5, and the refrigerant circulates between them. On the other hand, the lower portion of the ice storage tank 3 and the inlet of the outer pipe 2a are connected by a cold water supply passage 6 in which a water supply pump 8 is inserted, and the outer pipe 2a is also connected.
The outlet and the ice storage tank 3 are connected by a supercooled water return passage 7. Then, a return water from a load side (not shown) or a water supply passage 9 from a water supply source (not shown) is connected to the upper part of the ice storage tank 3, and the lower part of the ice storage tank 3 is , Cold water outlet 10 to the load side
Is connected.

The antifreezing structure of the present invention is realized by providing a heat insulating structure near the outlet of the heat exchanger 2. More specifically, as shown in FIG. 2, the inner pipe 2b is formed. A heat insulating member 11 having a predetermined length is attached to the outer peripheral surface of the. As the heat insulating member 11, for example, a heat shrink tube made of silicon rubber or a tube made of Teflon is used. According to the antifreezing structure, the heat exchanger 2
The supercooled water that has undergone heat exchange inside is often frozen due to instability in the supercooled state near the outlet of the heat exchanger 2, but the heat insulating member 11 mounted on the inner pipe 2b exchanges heat with the refrigerant. To prevent freezing.

Also, as shown in FIG. 3, even when an inner tube 2b having a concavo-convex shape formed by bellows-molding a stainless steel tube is used, the heat-shrinkable tube made of silicon rubber is used as the heat insulating member 11. For example, it is possible to obtain the same operational effects as in the case of the embodiment shown in FIG.

In the operation of the ice storage type cold water device, after supplying water to the ice storage tank 3 from the water supply passage 9 to a predetermined water level, the refrigerator 1 is driven to supply the refrigerant through the refrigerant supply passage 4 to the heat exchanger. The refrigerant that has been supplied into the inner pipe 2b of the second heat exchanger 2 and has undergone heat exchange is returned to the refrigerator 1 through the refrigerant return passage 5. On the other hand, the water in the ice storage tank 3 is supplied between the outer pipe 2a and the inner pipe 2b of the heat exchanger 2 through the cold water supply passage 6 by the drive of the water supply pump 8 and circulates in the inner pipe 2b. It exchanges heat with the cooling medium to become supercooled water and flows into the ice storage tank 3 through the supercooled return path 7. Then, the water temperature in the ice storage tank 3 becomes 0 ° C. or lower, and the ice pieces are separated into pieces, and a predetermined amount of ice is stored in the ice storage tank 3.

By the way, when the temperature of the water to be cooled supplied from the ice storage tank 3 to the heat exchanger 2 drops to near 1 ° C., the supercooled water is unstable near the outlet of the heat exchanger 2. However, since the heat insulating member 11 mounted on the outer peripheral surface of the inner pipe 2b cuts off heat exchange between the refrigerant and the water to be cooled to avoid a freezing factor, the heat exchanger is Freezing is prevented in the vicinity of the outlet 2 and the supercooled water is allowed to smoothly flow into the ice storage tank 3.

[0016]

As described above, the present invention relates to a supercooling water heat exchanger having a double pipe structure composed of an outer pipe and an inner pipe, and in the vicinity of the outlet of the supercooling water heat exchanger. In the above, since a heat insulating member of a predetermined length was attached to the outer peripheral surface of the inner pipe, heat exchange between the refrigerant and the water to be cooled was blocked near the outlet where the supercooled water was in an unstable state to avoid freezing factors. Therefore, it is possible to reliably prevent freezing near the outlet of the heat exchanger.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an ice storage type cold water device embodying the present invention.

FIG. 2 is an explanatory view showing a cross section near the outlet of the heat exchanger of FIG.

FIG. 3 is an explanatory view showing a cross-section of an example in which the inner tube shape of the heat exchanger of FIG. 2 is different.

FIG. 4 is an explanatory diagram showing a configuration of a conventional ice storage type cold water device.

5 is an explanatory view showing a cross section near the outlet of the heat exchanger of FIG. 4. FIG.

[Explanation of symbols]

 2 Heat exchanger for supercooled water 2a Outer pipe 2b Inner pipe 11 Insulation member

Claims (1)

[Claims] 1. A heat exchanger 2 for supercooling water having a double pipe structure comprising an outer pipe 2a and an inner pipe 2b, wherein the inner pipe 2b is provided in the vicinity of the outlet of the heat exchanger 2 for supercooling water. An antifreezing structure for a heat exchanger for supercooled water, characterized in that a heat insulating member 11 having a predetermined length is attached to an outer peripheral surface.