JPH08240364A - Supercooled water producing apparatus - Google Patents

Abstract

PURPOSE: To reduce the difference between flow rates of water flowing through an uppermost heat transfer pipe and a lowermost heat transfer pipe to stably continuously produce supercooled water and reduce conveyance power even when a large-sized shell and tube type supercooled water producing apparatus is constructed. CONSTITUTION: A supercooled water producing apparatus 8 is constructed such that water is introduced into a heat transfer tube 12 disposed in a body 11 through which a refrigerant flows and is brought into a supercooled state of 0 deg.C or lower. In the apparatus, there are formed areas S1 , S2 , where no heat transfer tube 12 is disposed, on the upper and lower portions in the body 11. There are formed cutouts 15 each having a configuration corresponding to the areas S1 , S2 , in outer peripheries of buffle plates B1 to B2 for supporting the heat transfer tube 12. The pressure difference based upon a head difference of the heat transfer tubes 12 located on the uppermost and lowermost portions is decreased so as to reduce the flow difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing supercooled water suitable for an ice heat storage system for air conditioning.

[0002]

2. Description of the Related Art An ice heat storage system is a heat storage system of a type in which cold heat of heat source water to be supplied to a water side heat exchanger of a fan coil unit or a water heat source heat pump is stored in a heat storage tank in the form of ice. Even a large-scale device has many advantages such as being able to store a large amount of cold heat. In such an ice heat storage system, the form of ice stored in the heat storage tank is
Considering the high ice filling rate and responsiveness to load demand, sherbet-shaped ones are superior.

The applicant has made various proposals for the technology for producing such sherbet-like ice, for example, Japanese Patent Laid-Open No. 114682/1989 and 1368/1996.
Japanese Patent No. 30 discloses a method and a device for continuously producing sherbet-like ice from supercooled water (supercooled water) of 0 ° C. or lower.

According to these known techniques, supercooled water is continuously discharged from the discharge port of the heat transfer tube of the supercooler into the air, and the discharge flow is collided with a supercooling releasing means such as a collision plate to generate an impact. By applying it, it became possible to continuously and efficiently generate sherbet-like ice in a slurry state with water (ice / water slurry).

In producing the supercooled water, a large number of small-diameter heat transfer tubes are arranged in a cylindrical main body (shell) which constitutes a cooling chamber and allows a refrigerant such as brine to flow. A subcooler having a structure in which water is passed through the heat pipe to exchange heat with the refrigerant is used. In this conventional so-called shell-and-tube type subcooler, separation plates are provided at both ends of the heat transfer tube or in the vicinity thereof,
The heat transfer tube is supported by penetrating the heat transfer tube on the separating plate.

Further, from the viewpoint of making the entire supercooler compact and evenly contacting the circulating refrigerant, as many heat transfer tubes as possible can be accommodated in the main body.
It is located all over the body. That is, the outermost heat transfer tube group and the heat transfer tube group are arranged so as to form a similar shape (circular shape) slightly smaller than the inner diameter of the main body.

[0007]

By the way, the demand for the above-mentioned ice heat storage system has been increasing more and more in recent years, and it has been adopted in, for example, a large-scale air-conditioning system in a building. It is also necessary to increase the capacity of the vessel itself.
A practical large-scale supercooled water production device having a large capacity of 1000 RT is also designed.

In order to increase the capacity of the subcooler itself, it is usually necessary to increase the number of heat transfer tubes to be accommodated, and correspondingly, the diameter of the tubular supercooler main body for accommodating the heat transfer tubes is increased, Further, it is possible to increase the total length of the heat transfer tube. In designing, the power required for operation and the efficiency of energy-heat conversion are also important evaluation factors.

When a large-sized subcooler is designed under the conventional technique in view of the above points, there are the following problems. That is, if the inner diameter of the subcooler body is increased and the number of heat transfer tubes is increased under the conventional technique of fully arranging the heat transfer tubes in the main body, the heat transfer tubes located at the top and the heat transfer tubes located at the bottom are A pressure difference due to a head difference becomes remarkable in the height direction between the heat pipe and the heat pipe.

Then, in a practical large-scale subcooler,
This water head difference corresponds to, for example, 30% to 40% of the frictional resistance in the tube, and the flow rate itself flowing in the heat transfer tube greatly differs between the uppermost part and the lowermost part, and as a result, the flow rate and cooling are different for each heat transfer tube. There will be a difference in temperature.

In order to stably generate supercooled water in the supercooler, the temperature condition inside the tube is an important factor, and thus the flow rate and temperature unevenness exist in the vertical direction of the heat transfer tube group. In this case, it becomes difficult to set all the pipes to the optimum operating conditions, which is one of the causes for lowering the heat exchange efficiency.

On the other hand, if the number of heat transfer tubes is increased or the total length of the heat transfer tubes is increased, it is necessary to support each heat transfer tube with a disc or the like in the middle portion of the heat transfer tube. In this case, it should be noted that the flow of the refrigerant flowing in the cooling chamber should not be obstructed, but the heat transfer tubes are prevented from coming into contact with each other, and the heat transfer tubes are prevented from coming into contact with the inner wall of the cooling room. The linearity of the heat transfer tube is prevented so that the ice inside the heat transfer tube can be easily discharged at the time of releasing the supercooling inside the tube in the case of a freezing trouble, and the curve is prevented. Guides the refrigerant so that it uniformly contacts the heat transfer tube group to exchange heat, adjusts the flow of the refrigerant in contact with the heat transfer tube group to control heat transfer, and is fixedly held at both ends of the subcooler In order to prevent loosening and cracking of the heat transfer tube group, consideration must be given to stable support of the entire heat transfer tube group to suppress vibration.

When the prior art is examined in view of these points, as described above, since the heat transfer tube is conventionally arranged so as to fill the inside of the subcooler main body, it is supported by the disc contacting the inner wall of the main body. In this case, in order to secure the circulation of the refrigerant, it is necessary to form a cutout or an opening in the disc. However, when a coolant passage is secured by forming a cutout having a large area to reduce the flow resistance of the coolant, the heat transfer tube located at the radial end (located near the outer circumference) has a cutout. Therefore, it is no longer supported by the disc.
Therefore, by changing the position of the notch for each disc,
For example, the outermost heat transfer tube is one of a plurality of arranged disks.
Every other span (i.e., twice the span if the disks are arranged with a fixed length span) is forced to be supported.

Then, the outermost heat transfer tube is
In contrast to being supported by a double long span, the heat transfer tube near the axis in the cooler body is in a state of being supported by half the span, and the support of each individual heat transfer tube becomes different, It is not preferable in terms of suppressing vibration. Further, since supporting it over a long span causes an instability factor, if the span itself is shortened in order to eliminate this, a large number of discs will be arranged in the cooler body. Then, the pressure loss of the refrigerant increases, which causes an increase in the carrier power of the refrigerant, such as an increase in the pump head and an increase in the required electric power, and the corresponding initial cost and running cost increase.

The present invention has been made in view of the above points, and even when a large-sized supercooled water production apparatus is configured, the difference in the flow rate of water flowing in the uppermost and lowermost heat transfer tubes is With the object of providing a supercooled water production apparatus that can be made smaller and that can easily secure the flow passage area of the refrigerant, and that can stably support the heat transfer tube, the object is to solve the above problems. is there.

[0016]

According to a first aspect of the present invention, there is provided a cooling chamber in which a refrigerant flows and a heat transfer tube arranged in the cooling chamber, and water is passed through the heat transfer tube. An apparatus for producing water in a supercooled state of 0 ° C. or less by causing water to exchange heat with the refrigerant, which is a substantially cylindrical cooling chamber horizontally closed at both ends and an axial direction. A plurality of heat transfer tubes which are arranged in parallel with each other in the cooling chamber and one end of which is open to the atmosphere side, and a plurality of baffle plates which have notches on the outer periphery and which support the intermediate portion of the heat transfer tubes in the cooling chamber. However, these baffle plates are arranged so that the cutouts thereof are alternately located above, below, above, below, ... In the cooling chamber, and the heat transfer tubes correspond to the cutouts of the baffle plate. The non-arranged area of the heat tubes, that is, the space where the heat transfer tubes are not Becomes arranged so as to form the bottom, supercooled water production apparatus is provided.

In this case, the shape of the baffle plate, that is, the axial longitudinal cross-sectional shape of the non-arranged area of the heat transfer tube is, as described in claim 2, a shape surrounded by arcs and chords.
Further, as described in claim 3, it is more practical and preferable to have a crescent shape surrounded by two arcs having different radii of curvature.

[0018]

According to the supercooled water producing apparatus of the present invention, the non-arranged areas are set above and below the cylindrical cooling chamber, and the heat transfer tubes are not arranged above and below the cooling chamber. Therefore, the pressure difference based on the head difference in the heat transfer tubes located at the uppermost part and the lowermost part can be made smaller than in the conventional case. Moreover, since the non-arranged area corresponds to the cutout portion of the baffle plate that supports the heat transfer tube, the heat transfer tube is not located in the cutout portion. Therefore, the cutout portion can be secured as the flow passage area of the refrigerant as it is, and the pressure loss of the refrigerant can be reduced. Also, as shown in Examples described later, it was confirmed that the amount of heat exchanged with the refrigerant itself hardly changed even if the number of heat transfer tubes near the cutouts was reduced.

Further, as described above, since the cutout portion of the baffle plate can be secured as the flow passage area of the refrigerant as it is, each baffle plate can support all the heat transfer tubes at that point, and each heat transfer tube can be supported. The support points and the support spans are all the same, and stable support of the heat transfer tubes is realized.

Further, according to the second and third aspects, since the non-disposed areas are formed in the upper and lower portions and the whole heat transfer tube group is in a cohesive form, there is no variation in vibration among the tubes, which is large. It has a structure that makes it difficult for vibration to occur.

Of course, in the supercooled water producing apparatus according to the present invention, the baffle plates are arranged such that the cutouts thereof are alternately located above, below, above, below, ... In the cooling chamber. Therefore, the refrigerant is guided so as to contact the heat transfer tube group in the cooling chamber without any bias.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a main configuration of an ice storage facility using a supercooled water producing apparatus according to an embodiment of the present invention. The heat storage tank 1 in the ice storage facility is in the form of an independent multi-tank type heat storage tank composed of three independent tanks 2, 3 and 4. Independent water intake pipes 5, 6, and 7 are connected to the bottoms of the tanks 2, 3, and 4, respectively, and the water in the tanks 2, 3, and 4 taken through a preheater or the like (not shown) is The supercooled water producing apparatus 8 installed outside the heat storage tank 1 is continuously supplied by the pump 10 through the transfer pipe 9.

The supercooled water producing apparatus 8 has an internal structure as shown in FIG. 2, and a heat transfer pipe (shell) is provided in a cylindrical main body (shell) 11 which constitutes a cooling chamber and is closed at both ends. A large number of tubes 12 are housed in parallel with the axial direction. One end of each heat transfer tube 12 penetrates one end wall 11a of the main body 11,
The opening 12a forming the discharge port is open to the atmosphere.

The other end of each heat transfer tube 12 penetrates a partition wall 13 provided in the main body 11 in a watertight manner, and its opening 12b has a water inlet header formed between the partition wall 13 and the other end wall 11b. It opens into the portion 14. Therefore, the vicinity of one end of each heat transfer tube 12 is supported by the one end wall 11 a of the main body 11, and the vicinity of the other end of each heat transfer tube 12 is supported by the partition wall 13. In addition, the other end wall 11b of the main body 11 is formed with an inlet 11c for introducing the water in the tanks 2, 3 and 4 taken by the pump 10 into the header portion 14.

As shown in FIGS. 2 and 3, the arrangement area of each heat transfer tube 12 in the main body 11 is a non-arrangement area S ₁ having a shape surrounded by arcs and chords above and below the main body 11. It is arranged so as to form S ₂ . The non-arranged areas S ₁ and S ₂ have the same size.

In order to prevent the inner wall of the main body 11 and the heat transfer tubes 12 from coming into contact with each other and the heat transfer tubes 12 themselves from being bent in the middle, it is necessary to support the heat transfer tubes 12 not only at both ends but also in the middle thereof. However, in this embodiment, the baffle plates B _{1 to} B ₆ having the configuration shown in FIG. 3 are provided in the main body 11 at equal intervals.

The baffle plates B _{1 to} B ₆ have the same shape and the same size, and have a diameter substantially the same as the inner diameter of the main body 11 as a whole, and the non-arrangement area S ₁ (S ₂ )
Is formed, that is, the notch 15 having a shape surrounded by an arc and a chord is formed. The baffle plates B _{1 to} B ₆ are arranged such that the notches 15 are alternately located in the non-arranged areas S ₁ and S ₂ of the heat transfer tube 12, that is, the main body 11
Are arranged so as to be positioned vertically, vertically, and vertically from one end side thereof.

Therefore, each heat transfer tube 12 is connected to each baffle plate B ₁
.About.B ₆ adapted to penetrate, which baffle plate B ₁
It is configured such that all of the positions B ₆ to B ₆ are supported. Note the As for the size of the non-arranged areas S _1, S ₂ and the notch 15, on the relationship between heat transfer tube array endmost penetrates the baffle plate B, not disposed area S _1, notch than S ₂ 1
The size of 5 is slightly smaller.

A brine inlet 16 is provided at the tip of the main body 11, that is, at the bottom of the zone defined by the one end wall 11a of the main body 11 and the baffle plate B ₁ .
On the other hand, a brine outlet 17 is formed on the rear end side of the main body 11, that is, on the upper portion of the zone defined by the baffle plate B ₆ and the front partition wall 13. And this brine entrance 1
When brine as a refrigerant supplied from the refrigerator 18 is supplied to the refrigerator 6, the brine passes through the notches 15 of the baffle plates B _{1 to} B ₆ and is passed into the heat transfer tubes 12. The water flows to the brine outlet 17 while exchanging heat with the water, and is again sent to the inlet of the refrigerator 18 by the brine pump 19 for circulation. Regarding the temperature of the brine, the inner surface temperature of the heat transfer tube 12 is 0 ° C to -5.8 ° C.
The control is performed as described above.

A heat insulating material 21 is provided on the outer periphery of the main body 11, and a heater such as a resistance heating wire is built in a protruding portion of each heat transfer tube 12 from one end wall 11a of the main body 11. A rubber type heat insulating material 22 is provided. With these configurations, it is possible to prevent the conduit of the heat transfer tube 12 from being frozen due to condensation of humidity in the air or growth of ice on the outer periphery of the main body 11.

An opening 12 serving as a discharge port of the heat transfer tube 12
The supercooled water below 0 ° C discharged into the atmosphere from
As shown in FIG. This vertical pipe 23 constitutes a supercooling releasing means,
It has a vertical pipe having an inner diameter sufficient to receive the discharge flow of the supercooling water, and further, the upper end thereof is tapered to form a receiving portion 23a. Then, the supercooled water discharged from the opening 12 a of the heat transfer tube 12 is supplied to the vertical pipe 23.
Due to the impact when it falls inside, the supercooled state is released, and ice / water slurry is formed in the vertical pipe 23 by the fluid fine ice and water.

The lower portion of the vertical pipe 23 communicates with a carrier pipe 24, and the carrier pipe 24 is connected with distribution pipes 25, 26, 27 in the tanks 2, 3, 4. Therefore, the ice / water slurry in the vertical pipe 23 is supplied to the distribution pipes 25, 26,
It is supplied to each of 2, 3, 4 through 27 and is adapted to store ice.

The ice storage equipment employing the supercooled water producing apparatus 8 according to this embodiment is constructed as described above,
During ice making and ice storage operations performed at night, the pump 10
By the operation of the, the intake pipes 5, 6, 7 from each tank 2, 3, 4
Water is uniformly taken through and is passed through each heat transfer tube 12 of the supercooled water producing apparatus 8. On the other hand, the operation of the pump 19 and the refrigerator 18 causes the brine to circulate in the main body 11 of the supercooled water production apparatus 8. As a result, heat exchange between the brine and water is performed, supercooled water of 0 ° C. or less is discharged from the opening 12a of the heat transfer tube 12, and ice / water slurry is continuously generated in the vertical pipe 23. . In this case, the baffle plates B _{1 to} B ₆
Since each notch 15 is arranged so as to be vertically, vertically and vertically from one end side of the main body 11, the brine introduced from the brine inlet 16 is alternately guided by the notches 15 which are vertically positioned. Brine exit 1
Guided to 7. Therefore, in the main body 11, the brine comes into contact with the group of heat transfer tubes 12 without any bias, and heat is exchanged.

Since the heat transfer tubes 12 are arranged such that the non-arranged areas S ₁ and S ₂ are formed vertically, even if the tube diameter of the main body 11 becomes large, In comparison with the arrangement configuration in which the heat transfer tubes are fully arranged in the above, the pressure difference of the water flow based on the head difference of the heat transfer tubes 12 located in the upper and lower parts of the main body 11 is smaller. Therefore, it is possible to reduce the flow rate difference and the temperature unevenness as compared with the conventional case, and it is possible to stably and continuously generate the supercooled water.

Moreover, the cutout portions 15 of the baffle plates B _{1 to} B ₆ supporting the heat transfer tubes 12 have the non-arranged areas S ₁ and S _{2 respectively.}
Therefore, each heat transfer tube 12 is supported by all the baffle plates B _{1 to} B ₆ under the same condition. Therefore, the support spans of the individual heat transfer tubes 12 are all the same. Therefore, the supporting span can be shortened, stable support can be realized, and vibration and the like are less likely to occur than in the case where the heat transfer tubes at the outermost end are supported by every other baffle plate. Further, since the cutout portion 15 has the same flow passage area of the brine as it is, it is easy to guide the brine in the main body 11 smoothly and without deviation.

By the way, in the supercooled water producing apparatus 8 according to the present embodiment, the non-arranged areas S ₁ and S ₂ of the heat transfer tubes 12 are set up and down in the main body 11 as described above. The ice making capacity is comparable to the conventional supercooled water production device of this type in which a heat transfer tube is arranged.

To show this, for example, the ice making capacity 400
A case of realizing [RT] will be described as an example. For example, in the supercooled water producing apparatus 8 according to the above embodiment, the main body 11 has a diameter of 746 mm (750 A), the number of heat transfer tubes 12 having an inner diameter of 8 mm is 1703, and the cutout portion 1 of the baffle plate B is
In the case of setting the cut ratio of 5 (ratio of the length L of the cutout to the diameter) to 20%, and in the supercooled water production apparatus 41 according to the related art shown in FIG.
Heat transfer tube 42 of 5.2 mm (700 A) and inner diameter of 8 mm is attached to the main body 4
Comparing with the case where the number is set to 1955 and the number of the cutouts 43 of the baffle plate 42 (the ratio of the length M of the cutouts to the diameter of the main body 41) is 31%. , As shown in the table of FIG.

According to this, in obtaining the same ice making capacity, the temperature difference between the brine inlet and outlet and the brine flow rate are shown in FIG.
The conventional type shown in 1 above is somewhat superior. However, since the pressure loss of the brine is smaller in this embodiment, the brine pump 19 is operated efficiently. Since the wall surface temperature difference in the main body 11 is also smaller in this embodiment, it is presumed that the temperature difference between the heat transfer tubes 12 located above and below is also smaller. And pump 10
The required transport power of No. 1 is smaller in this embodiment, and the cost during ice storage operation is less in this embodiment.

In addition, in order to obtain the same ice making capacity, the pipe diameter of the main body (shell) itself becomes a little larger, but the number of heat transfer pipes (tubes) can be reduced by 200 or more. The structure of the water production device is simplified, maintenance is easy, and the number of troubles occurring in the heat transfer tube itself is further reduced. Therefore, from this point of view, the present embodiment is practically superior.

In the above-mentioned embodiment, the non-arranged areas S ₁ and S ₂ of the heat transfer tube 12 formed in the main body 11 have a cross section formed by arcs and chords.
As shown in FIG. 6, even if the heat transfer tubes are arranged in the main body 11 so as to form so-called crescent-shaped non-arranged areas S ₃ and S ₄ surrounded by two arcs having different diameters (see FIG. 6).
The shaded portion in the middle), the same effect as that of the above-mentioned embodiment can be obtained.

In the supercooled water producing apparatus 8 according to the above embodiment, the brine inlet 16 is located at the bottom of the main body 11,
Although the brine outlet 17 is provided in the upper portion of the main body, the present invention is not limited to this, and the brine inlet and the brine outlet may be set in the same direction such that both are the bottom portion and both are the upper portion. For example, like the supercooled water producing apparatus 51 shown in FIG. 7, the brine inlet 52 on the front end side may be set on the upper portion of the main body 53, and the brine outlet 54 on the rear end side may also be set on the upper portion of the main body 53. In this case as well, the cutouts 15 of the baffle plates B _{1 to} B ₇ supporting the heat transfer tubes 55 are arranged in the order of lower top, bottom, top, bottom, top and bottom. When the brine inlet and the brine outlet are set in the same direction as in the supercooled water production apparatus 51, for example, piping work after installing the supercooled water production apparatus becomes very easy.

[0042]

According to the supercooled water producing apparatus of the present invention, the pressure difference based on the head difference in the heat transfer tubes located at the uppermost part and the lowermost part can be made smaller than before.
It is easy to alleviate the flow rate unevenness and temperature unevenness and set all the heat transfer tubes to the optimum operating condition, and the energy and heat conversion efficiency can be improved. In addition, since the cutout portion of the baffle plate can be secured as it is as the flow passage area of the refrigerant, it is easy to reduce the pressure loss of the refrigerant, and reduce the load on the power source such as a pump that distributes the refrigerant to reduce the cost. It is also possible to let. Moreover, each heat transfer tube is stably supported,
It is possible to suppress the occurrence of vibration.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a system of an ice storage facility using a supercooled water production system according to an embodiment of the present invention.

FIG. 2 is a cross-sectional explanatory view of a side surface of the supercooled water producing apparatus according to the embodiment of the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is an axial cross-sectional explanatory view of a supercooled water producing apparatus according to a conventional technique.

FIG. 5 is a table showing a performance comparison between a supercooled water production apparatus according to an embodiment of the present invention and a conventional supercooled water production apparatus.

FIG. 6 is an axial cross-sectional explanatory view of a supercooled water producing apparatus according to another embodiment of the present invention.

FIG. 7 is a side cross-sectional explanatory view of a supercooled water producing apparatus according to another embodiment in which the brine inlet and the brine outlet are in the same direction.

[Explanation of symbols]

1 Heat Storage Tank 8 Supercooled Water Production Device 11 Main Body 12 Heat Transfer Tube 12a Opening 14 Header 15 Cutout B ₁ ~ B ₆ Baffle Plate S ₁ , S ₂ Non-arrangement Area

Claims (3)

[Claims] 1. A supercooled state of 0 ° C. or less, comprising a cooling chamber in which a refrigerant flows and a heat transfer tube arranged in the cooling chamber, water is passed through the heat transfer tube to exchange heat with the refrigerant. Is a device for producing water, which is a substantially cylindrical cooling chamber having horizontally closed both ends, and a cooling chamber arranged parallel to the axial direction and having one end opened to the atmosphere side. It has a plurality of heat transfer tubes and a plurality of baffle plates that have cutouts on the outer periphery and support the intermediate portion of the heat transfer tubes in the cooling chamber, and these baffle plates have their cutouts alternately up and down in the cooling chamber. A supercooled water producing apparatus, which is arranged so as to be positioned, and further wherein the heat transfer pipes are arranged so as to form non-arranged areas of the heat transfer pipes corresponding to the notches of the baffle plate above and below the cooling chamber. 2. The supercooled water manufacturing apparatus according to claim 1, wherein the notch has a shape surrounded by an arc and a chord. 3. The supercooled water manufacturing apparatus according to claim 1, wherein the notch has a crescent shape.