JPH0972582A - Thermal storage type cold water device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve efficiency when cold is taken out by a method wherein in a cold water device of the ice thermal storage type, ice is prevented from being formed into blocks when ice is produced again and ice is smoothly melted at the time of a cold utilization operation. SOLUTION: In a thermal storage type cold water device in which ice is produced around heat transfer tubes in a thermal storage tank 60 and cold is taken out while the ice is being melted, after a cold utilization operation, a water level sensor LS senses whether there is any residual ice and when there is a residual ice, a predetermined amount of cooling water W is discharged from the tank 60 and thereafter tap water W' having higher temperature than the water W in the tank 60 is supplied in the same quantity as the quantity of discharged cooling water W and the water W, W' is circulated between the tank 60 and thermal loads for a predetermined time. Such operation is repeated until no residual ice is left.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention stores ice as a cold heat source in a heat storage tank, melts the ice to take out cold water at a predetermined temperature, and cools the cold water to cool various equipment and cool indoors. Relating to a heat storage type cold water device for use in
The present invention relates to measures for avoiding blocking of ice caused by generation of ice around the residual ice during ice making.

[0002]

2. Description of the Related Art Conventionally, a so-called direct expansion type, as disclosed in Japanese Patent Laid-Open No. 6-74499, is known as one type of heat storage type cold water device. This type of heat storage type cold water device includes a chilling unit including a compressor, a condenser and the like, and a heat storage unit including a heat storage tank for storing water for ice making, and extends from the chilling unit in the heat storage tank of the heat storage unit. A heat transfer tube is provided. And
During the heat storage operation, water is cooled while evaporating the liquid refrigerant from the chilling unit in the heat transfer tube, ice is generated on the outer peripheral surface of the heat transfer tube, and cold heat is stored in the heat storage tank. Also, during cold heat utilization operation, water is circulated between the heat storage tank and the heat load so that the circulating water melts the ice around the heat transfer tubes while cooling heat is taken out from the heat storage tank to cool the heat load. I have to.

Further, in order to obtain a predetermined amount of cold water for cooling this heat load, it is necessary that ice is always present in the heat storage tank during the cold heat utilization operation. Therefore, the cold heat utilization operation is performed. At the end, some ice will remain. Then, when the heat storage operation is started again from this state,
Since the temperature around the remaining ice portion is particularly low, a large amount of ice is generated in this portion, which causes so-called block formation in which the amount of ice making locally increases. Then, when this block formation occurs, the flow path of the water in the heat storage tank cannot be properly obtained during the cold heat utilization operation, and as a result, the ice is not melted smoothly and the cold heat extraction efficiency decreases. .

In order to avoid such blocking of ice, various measures have been taken conventionally. For example, in the one shown in FIG. 12, the water supply pipe on the downstream side of the water pump (b) for circulating water between the heat storage tank (a) and the heat load is branched, and one of the water supply pipes (c1) is branched. Connect the downstream end to one end of the heat storage tank (a) (upper part in Fig. 12), and connect the other water supply pipe (c2)
The downstream end of the heat storage tank (a) is connected to the other end (lower part of Fig. 12), and each water supply pipe (c1, c2) is equipped with an on-off valve (d1, d2), while two Equipped with drainage pipes (e1, e2) of
Connect the upstream end of one drain pipe (e1) to one end of the heat storage tank (a) (Fig. 1).
2), the other end of the drainage pipe (e2) is connected to the other end of the heat storage tank (a) (lower part of Fig. 12), and the drainage pipes (e1, e2) The on-off valves (f1, f2) are provided in each. By switching the open / closed state of each on-off valve (d1, d2, f1, f2), it is possible to switch between the water circulating state shown by the solid line and the water circulating state shown by the broken line in FIG.
By supplying water from the water supply pipes (c1, c2) corresponding to the portion with a large amount of residual ice, water with a relatively high temperature is made to flow through the residual ice portion to promote the melting of ice. That is, if there is residual ice in the upper part of the heat storage tank (a), the open / close valve (d1,
f2) is opened to create the circulation state shown by the solid line, while relatively high-temperature water is allowed to flow in the upper part of the heat storage tank (a), while the heat storage tank
If there is residual ice in the lower part of (a), the on-off valve (d2, f
1) is opened and the circulation state shown by the broken line is made so that water having a relatively high temperature is made to flow in the lower part of the heat storage tank (a).

Further, in the one shown in FIG. 13, the heat storage tank (a)
Provide a heat transfer tube (g) with a sensor (h, h) that detects the thickness of ice (i) generated around the heat transfer tube so that the thickness of ice (i) does not exceed a specified value. It controls the ice making operation.

[0006]

However, in each of the above-mentioned configurations, it was not possible to reliably avoid the blocking of ice. In other words, in the former configuration, the part where ice blocking is likely to occur changes as the water circulation state is switched, so unless the ice is accurately recognized to be completely melted, the ice block is blocked. Therefore, the area where the change occurs will be enlarged. Also water pump
When the temperature of the circulating water supplied from (b) to the heat storage tank (a) is low, there was a problem that it took a long time to completely melt the ice.

In the latter configuration, it is possible to prevent blocking only in the portion where the sensor is arranged, so there is a concern that blocking may occur in the portion where the sensor is not arranged. Further, in order to prevent blocking in the entire heat storage tank, it is necessary to sufficiently consider the position of the sensor and to install a large number of sensors, which is difficult to set and the installation work is complicated. It also becomes

The present invention has been made in view of these points, and avoids blocking of ice during ice making again, and smoothly melts ice during cold heat utilization operation to improve the efficiency of extracting cold heat. The purpose is to improve.

[0009]

In order to achieve the above object, the present invention according to claim 1 provides a high temperature ice making liquid from the outside when residual ice is generated in the heat storage tank. The supply ensured that the ice would melt.

Specifically, as shown in FIG. 1, a heat storage tank (60) for storing the ice making liquid (W) and a heat transfer tube (7a) immersed in the ice making liquid (W) are provided. During the ice making operation, a heat exchange fluid is circulated through the heat transfer tube (7a) to perform heat exchange between the heat exchange fluid and the ice making liquid (W) to obtain the ice making liquid.
(W) is cooled to below freezing and ice is made on the outer peripheral surface of the heat transfer tube (7a) to store cold heat in the heat storage tank (60). Liquid for ice making among
(W) is circulated, and this ice making liquid (W)
It is premised on a heat storage type cold water device that melts ice (I) in 0) to take out cold heat. Then, a residual ice detecting means (LS) for detecting residual ice in the heat storage tank (60), and the heat storage tank (6
Liquid discharging means (6d) for discharging the ice-making liquid (W) from inside (0)
A melting liquid supply means (6P) for supplying an ice-making liquid (W ') having a temperature higher than that of the ice-making liquid (W) in the heat storage tank (60) into the heat storage tank (60), After completion, the remaining ice detection means
When the residual ice in the heat storage tank (60) is detected by the (LS), the liquid discharge means (6d) is controlled so as to discharge a predetermined amount of the ice making liquid (W) from the heat storage tank (60), and Melting liquid supply means (6P) so as to supply the high temperature ice making liquid (W ') to the heat storage tank (60)
And a residual ice melting control means (51) for controlling the above.

With such a structure, when there is residual ice in the heat storage tank (60) after the end of the cold heat utilization operation, a low temperature ice making liquid (W) and a high temperature ice making liquid (W ') are used. Are replaced, the temperature inside the heat storage tank (60) rises, which causes the residual ice to melt. For this reason, the blocking of ice, which has occurred at the time of re-ice making due to the presence of residual ice as in the past, can be avoided.

According to a second aspect of the present invention, in the heat storage type cold water device according to the first aspect, the residual ice detecting means is a heat storage tank (6
The water level sensor (LS) detects the water level of the ice making liquid (W) in (0) and detects the presence of residual ice when the water level is equal to or higher than a predetermined water level. Then, the discharge amount of the ice making liquid (W) by the liquid discharging means (6d) and the supply amount of the high temperature ice making liquid (W ') by the melting liquid supplying means (6P) are set to the same amount. .

With this configuration, the water level of the ice-making liquid (W) in the heat storage tank (60) changes depending only on the presence or absence of residual ice, so that no special residual ice detecting means is used.
The water level sensor (LS) can detect the presence of residual ice.

According to a third aspect of the present invention, in the heat storage type cold water device according to the first or second aspect, the residual ice melting control means is provided.
(51), at the same time as supplying the high temperature ice-making liquid (W ') into the heat storage tank (60) by the melted liquid supply means (6P), the ice-making liquid (between the heat storage tank (60) and the heat load ( The structure is such that W, W ') is circulated.

According to this structure, the temperature in the entire heat storage tank (60) can be raised substantially uniformly, so that it is possible to avoid the situation where the residual ice remains locally, and the entire inside of the heat storage tank (60) can be avoided. The ice can be completely melted over.

According to the fourth aspect of the present invention, the heat storage tank is divided into a plurality of storage chambers, and the ice making state in each storage chamber is changed according to the amount of remaining ice.

Specifically, as shown in FIG. 2, a plurality of storage chambers (6b, 6b ', ...) Are provided, and an ice making liquid (W) is stored in each storage chamber (6b, 6b', ...). Heat storage tank (60) and each of the above storage chambers (6b,
6b ', ...) Heat transfer tubes (7a, 7a', ...) that are immersed in the ice making liquid (W) and through which the heat exchange fluid flows, and the heat transfer tubes (7a, 7a ', ...)
Fluid adjusting means (31, 31, ...) for adjusting the flow rate of the heat exchange fluid in the heat transfer tube (7).
a, 7a ', ...) is circulated through the heat exchange fluid to exchange heat between the heat exchange fluid and the ice-making liquid (W), and the ice-making liquid (W) is cooled to below the freezing point. By making ice on the outer peripheral surface of each heat transfer tube (7a, 7a ', ...), cold heat is stored in the heat storage tank (60), and during operation using cold heat, from a predetermined storage chamber (6b) to another storage chamber.
While circulating the ice-making liquid (W) toward (6b ') in order, the ice-making liquid (W) is circulated between the heat storage tank (60) and the heat load,
This ice-making liquid (W) melts ice (I) and heat storage tank (6
It is premised on a heat storage type cold water device that takes out the cold heat in 0). Then, the remaining ice amount detecting means (LS) for detecting the amount of remaining ice in the heat storage tank (60), and during the ice making operation, the heat storage tank (60) detected by the remaining ice amount detecting means (LS) Based on the amount of remaining ice in the storage chamber, the amount of ice made in the upstream storage chamber (6b)
(6b ') Fluid adjustment means (3
1, 31, ...) for controlling the amount of ice making (52).

With such a structure, by suppressing the ice making in the storage chamber (6b ') on the downstream side where residual ice is likely to occur, it is possible to block the ice in the storage chamber (6b') on the downstream side. It can be avoided. That is, by securing a sufficient amount of ice making in the upstream storage chamber (6b), it is possible to avoid blocking ice while securing a sufficient amount of heat storage.

According to a fifth aspect of the present invention, in the heat storage type cold water apparatus according to the fourth aspect, the ice making amount control means (52) is provided, when the remaining ice amount in the entire heat storage tank (60) is a predetermined amount or more, While controlling the fluid adjusting means (31, 31, ...) so as to perform ice making only in the upstream storage chamber (6b), when the remaining ice amount is less than or equal to the above predetermined amount, the remaining ice amount and the ice making amount are Fluid adjustment means (31, 31) to perform the same amount of ice making per unit time in each of the upstream storage chamber (6b) and the downstream storage chamber (6b ') until the total ice making volume, which is the sum, exceeds a predetermined amount. , ...) are controlled.

With such a structure, the storage chamber (6
It is possible to perform ice making to the extent that ice blocking does not occur in b '), and it is possible to avoid ice blocking while securing a sufficient amount of heat storage in the heat storage tank (60) as a whole.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in FIGS. 3 and 4, the heat storage type cold water device (10) is constructed by connecting the heat storage unit (30) to the chilling unit (20) and produces a cooling water (W). Are configured.

The chilling unit (20) includes a compressor (21).
An oil separator (22), an air heat exchanger (23) that is a heat source side heat exchanger equipped with a fan (2F), a receiver (24), and a chilling side solenoid valve (SV-1), A capillary tube (25) that is an expansion mechanism and a water heat exchanger (26) that is a liquid heat exchanger are sequentially connected by a refrigerant pipe (2a). The water heat exchanger (26) is a shell-and-tube heat exchanger, one end of which is connected to the capillary tube (25) and the other end of which is connected to the suction side of the compressor (21). As shown in FIG. 4, an outward path (41) and a return path (42) of a water system (40) in which cooling water (W) that is an ice making liquid circulates are connected.

Further, the compressor (21) and each solenoid valve described later.
(SV-1, SV-2) and electric three-way valve (4V)
0), the controller (50) is connected to the compressor (21)
It is designed to control the operating capacity and the opening / closing operation of each valve (SV-1, SV-2, 4V).

The heat storage unit (30) includes a liquid side refrigerant pipe (3
L) and the gas side refrigerant pipe (3G) are connected to the chilling unit (20), and the heat storage unit (30) and the chilling unit (20) allow the refrigerant to circulate in a closed circuit refrigerant circuit.
It constitutes (11). And the liquid side refrigerant pipe (3L)
Is connected between the receiver (24) and the capillary tube (25) via a heat storage side solenoid valve (SV-2), while the gas side refrigerant pipe (3G) is connected via a one-way valve (CV). Connected to the suction side of the compressor (21).

In the heat storage unit (30), as shown in FIG. 5, the inside of the heat storage tank (60) in which the cooling water (W) is stored is divided into a plurality of storage chambers by partition plates (6a, 6a ', ...). It is divided into (6b, 6b, ...), and the heat storage heat exchangers (70, 70, ...) are stored in each storage chamber (6b, 6b, ...). This heat storage heat exchanger (7
0) is equipped with a heat transfer tube (7a) bent at multiple points,
As shown in Fig. 3, both ends of this heat transfer pipe (7a) are connected to the liquid side refrigerant pipe (3
L) and the branch pipe (3L-a, 3G-a) of the gas side refrigerant pipe (3G), respectively. The liquid branch pipe (3L-a) is provided with a temperature-sensitive heat storage expansion valve (31) as a fluid adjusting means,
A liquid gas heat exchanger (32) is provided between the liquid branch pipe (3L-a) and the gas branch pipe (3G-a), and the liquid gas heat exchanger is provided in the gas branch pipe (3G-a). Downstream of (32), the temperature sensing part (31-
a) is provided. Also, each of the above partition plates (6a, 6a ', ...)
Is the first partition plate (6a) whose upper end is lower than the water surface of the cooling water (W) and the second partition plate (6a ') whose lower end is higher than the bottom surface of the heat storage tank (60). ) And are arranged alternately. As a result, each storage chamber (6b, 6b, ...)
The cooling water (W) in the heat storage tank (60) flows between the storage chambers (6b, 6b, ...) because they communicate with each other through the space above or below (6a, 6a '). It is flowable. In this way, since the storage chambers (6b, 6b) are in communication with each other, the water levels in the storage chambers (6b, 6b,…) are the same as each other, and
This water level becomes higher as the amount of ice making in the entire heat storage tank (60) increases.

Further, as shown in FIG. 4, the inlet side and the outlet side of the heat storage tank (60) are connected to the outward path (41) of the water system (40), and the inlet side is connected by an electric three-way valve (4V). Outbound of water system (40) (41)
It is connected to the. Further, at the bottom of the heat storage tank (60) near the inlet side, there is a cooling water introduction pipe (43) connected to the outward path (41) of the water system (40), and at the bottom near the outlet side of the water system (40). Outbound (41)
The cooling water lead-out pipe (44) connected to each is provided, and the cooling water (W) introduced from the inlet side is the cooling water introduction pipe (43).
Is introduced into the heat storage tank (60) from the inside of the heat storage tank (60), passes through the upper side or the lower side of the partition plates (6a, 6a ') and sequentially flows through the storage chambers (6b, 6b, ...), and then the cooling water outlet pipe ( It is designed to be led out from the exit side via 44) (see the arrow in Fig. 5). Further, as shown in FIG. 4, the water system (40) has a circulation pump (4P) provided in the outward path (41) and is connected to a cooling unit as a heat load (not shown). And the cooling water
(W) flows into the water heat exchanger (26) from the return path (42) of the water system (40) and is cooled, and then from the forward path (41) of the water system (40) to the electric three-way valve (4V). All or part of it flows through the heat storage unit (30) and is cooled again, and then returns to the forward path (41) to cool the water from the water heat exchanger (26) and the cooling water from the heat storage unit (30). And so that and become a predetermined temperature (for example, 2 ℃),
It will flow to the cooling unit.

Further, the heat storage tank (60) is provided with a water level sensor (LS) as residual ice detecting means for detecting the amount of residual ice and the total amount of ice making, while the air system (80) is connected. There is. The air system (80) comprises a supply pipe (82) connected to an air pump (81) and a suction pipe (83) connected to a heat storage tank (60), and the supply pipe (82) is a one-way valve. (CV1) via heat storage tank (6
It is introduced in the lower part of 0). And the air system (80)
Supplies bubbles to the cooling water (W) in the heat storage tank (60) to stir the cooling water (W) to promote ice making and defrosting. In addition, from this supply pipe (82), each storage chamber (6b, 6b,
The bubble supply operation to ...) can be switched between the bubble supply state and the supply stop state for each storage chamber (6b, 6b, ...). An overflow pipe (6f) is provided in the heat storage tank (60) so that the water level in the heat storage tank (60) does not become higher than a predetermined water level.

The heat storage tank (60) is a feature of this embodiment.
The drain pipe (6d) as a liquid discharge means for discharging the cooling water (W) in the heat storage tank (60) and the molten liquid supply means for replenishing the cooling water (W) in the heat storage tank (60). Makeup water pipe (6
P) is connected. The drain pipe (6d) has its upstream end connected to the bottom of each storage chamber (6b, 6b, ...), and the overflow pipe (6f) via the one-way valve (CV2) and solenoid valve (SV-3). The storage chamber (6
Cooling water is discharged from b, 6b). On the other hand, the makeup water pipe (6P) is arranged above the overflow pipe (6f) above the side surface of the heat storage tank (60), and is provided with a solenoid valve (SV-4). With the opening of the valve (SV-4), water (tap water) with a relatively high temperature is stored in the heat storage tank (6
It will be replenished within 0). Each of these solenoid valves (SV-
The opening control of (3, SV-4) is performed by the residual ice melting control means (51) provided in the controller (50). The residual ice melting control means (51) drives the circulation pump (4P) with the opening of the solenoid valve (SV-4).

Next, the operation of the heat storage type cold water device (10) will be described. In this embodiment, before starting the heat storage operation, the water level in the state where there is no ice (I) in the heat storage tank (60) is recognized as the initial water level in advance, and then the heat storage tank (60) stores cold heat. Start operation (when making ice). In this heat storage operation, the chilling side solenoid valve (SV-1) is closed, the heat storage side solenoid valve (SV-2) is opened, and the high-pressure refrigerant discharged from the compressor (21) is the air heat exchanger. It is condensed at (23) and becomes a liquid refrigerant, which is once stored in the receiver (24). afterwards,
The liquid refrigerant does not flow into the water heat exchanger (26), and the heat storage unit
Flowing to (30), the heat transfer tubes (7a,
7a,…), after decompressing with each heat storage expansion valve (31, 31,…), it evaporates in each heat transfer pipe (7a, 7a,…) and becomes a gas refrigerant to the compressor (21). Will return.

Then, each heat storage heat exchanger (70, 70, ...)
Heat exchange with the cooling water (W), cools the cooling water (W), and produces ice (I) on the surface of each heat transfer tube (7a, 7a, ...) (see Fig. 5) to store cold heat. It will be stored in the tank (60). The ice-making amount of the generated ice (I) uses the fact that the water level of the cooling water (W) rises as the ice-making amount increases.
It will be recognized by detecting the water level by S).

During the cooling operation utilizing the cold heat (cold heat utilization operation), the chilling side solenoid valve (SV-1) is opened, the heat storage side solenoid valve (SV-2) is closed, and the compressor ( The high-pressure refrigerant discharged from 21) is condensed in the air heat exchanger (23) to become a liquid refrigerant, and is temporarily stored in the receiver (24). afterwards,
The liquid refrigerant does not flow into the heat storage unit (30), is decompressed by the capillary tube (25) and evaporated in the water heat exchanger (26), and becomes a gas refrigerant and returns to the compressor (21). .

On the other hand, the cooling water is so-called feed water temperature controlled and flows from the return path (42) of the water system (40) to the water heat exchanger (26),
It is cooled by exchanging heat with the refrigerant, for example, cooling water is cooled to 7 ° C. Then, all or part of the cooling water exiting the water heat exchanger (26) flows into the heat storage tank (60) through the electric three-way valve (4V), that is, the cooling water cooled in the heat storage unit (30). And the cooling water cooled only by the water heat exchanger (26).

The cooling water flowing into the heat storage tank (60) is cooled while melting the ice (I) generated on the surface of the heat transfer tubes (7a, 7a, ...) And then cooled, and then the water system (40). Returning to the forward route (41), the cooling water cooled only by the water heat exchanger (26)
It joins with (W) and is controlled by cooling water (W) at 2 ° C., for example. The cooled cooling water (W) flows into the cooling section and exchanges heat with air or the like in the cooling section.

After such a cooling operation is completed, the residual ice melting operation, which is a feature of this embodiment, is started. In this residual ice melting operation, as shown in FIG. 6, first, with the operation of the chilling unit (20) stopped, first, the solenoid valve (SV-3) of the drain pipe (6d).
And the cooling water (W) is discharged from the heat storage tank (60) by a predetermined amount. This discharge amount is determined, for example, by setting the opening time of the solenoid valve (SV-3) to a predetermined time. After that, the solenoid valve (SV-4) of the makeup water pipe (6P) was opened, and the heat storage tank (6
Tap water having a higher temperature (for example, 20 ° C) than the cooling water in 0)
(W ') is supplied into the heat storage tank (60). This supply amount is set to the same amount as the amount of the cooling water (W) discharged by the drain pipe (6d) in the drainage operation. In other words, the low temperature cooling water (W) and the high temperature tap water (W ') have been replaced. Then, at the same time as this water supply operation, the circulation pump (4P) is driven to circulate the water (W, W ') between the heat storage tank (60) and the cooling unit for a predetermined time (for example, 30 minutes). As a result, inside the heat storage tank (60), cooling water (W) and tap water (W ')
Since and will be circulated in a mixed state, the heat storage tank
The temperature of the entire inside of the (60) is improved almost evenly, and this heat storage tank (6
The residual ice (I) in 0) will be rapidly melted. On this occasion,
If air bubbles are supplied into the heat storage tank (60) by the air system (80),
Can melt ice (I) more efficiently.

After such operation, the solenoid valve (SV-4) of the makeup water pipe (6P) is closed, and the circulation pump (4P) is stopped,
The water level sensor (LS) detects the water level in the heat storage tank (60). Then, this detected water level is compared with the above-mentioned initial water level (water level in the absence of ice), and if the detected water level is higher than the initial water level, it is recognized that there is still residual ice, and the above-mentioned residual ice melting Restart the operation. In this way, the residual ice melting operation is repeatedly performed until it is recognized that the residual ice is exhausted. As a result, the generation of residual ice in the heat storage tank (60) is reliably prevented, and during re-ice making operation, the blockage of ice (I) due to the presence of residual ice can be reliably prevented, and the cold heat It is possible to smoothly melt the ice (I) during the use operation and improve the efficiency of extracting cold heat. The tap water (W ') supplied from the makeup water pipe (6P) is the cooling water for ice making during the ice making operation.
Used as (W). Therefore, new water (W) always exists in the heat storage tank (60), so that the generation of dirt in the heat storage tank (60) is suppressed and the cleaning frequency can be reduced.

The position of the supply port of the makeup water pipe (6P) is the storage chamber (6b) located at the most downstream side among the storage chambers (6b, 6b, ...).
It is preferable to correspond to. This is because the storage chamber (6b) located on the most downstream side is in a state where residual ice is likely to occur, so by reliably supplying hot water (W ') to this part of the ice (I) This is to ensure melting.

(Second Embodiment) Next, a second embodiment according to the present invention will be described. The configuration and the cooling operation of the heat storage type cold water device of the present embodiment are substantially the same as those of the above-described first embodiment, and therefore description thereof will be omitted.

As a feature of this embodiment, during the heat storage operation, the ice making operation in each storage chamber (6b, 6b, ...) Is based on the amount of remaining ice in each storage chamber (6b, 6b, ...). To control. Here, in order to facilitate understanding of the ice making operation, a case where there are two storage chambers (6b, 6b) (tanks) in the heat storage tank (60) will be described. In this case, the internal temperature of each tank, the inlet temperature of the heat storage tank, the outlet temperature, and the water level in the heat storage tank during the cooling operation change as shown in FIG. 7. In addition, the amount of residual ice in each storage chamber (6b, 6b) at this time changes as shown in FIG. That is, although the melting of ice (I) is promoted in the storage chamber (tank A) located on the upstream side in the flow direction of the cooling water (W), residual ice remains in the storage chamber (tank B) located on the downstream side. It is in a state where it easily occurs. In this embodiment, by utilizing such characteristics, the heat storage operation is performed while estimating the residual ice in each storage chamber according to the water level.

The operation during the heat storage operation in this embodiment will be described below with reference to the flowchart of FIG. In this flow chart, the inside of the heat storage tank (60) is divided into two storage chambers (6b, 6b) of tank A and tank B, and cooling water flows from tank A toward tank B. The operation when the present invention is applied to the above-described one is shown.

First, in step ST1, the total amount of ice making stored in the heat storage tank (60) at the end of the heat storage operation is set. This is to set the total amount of ice making by determining the water level after the end of the heat storage operation. It is the difference between the maximum water level (MAX water level) in the heat storage tank and the initial water level in the absence of residual ice. It is calculated by multiplying by a predetermined load condition. That is, the total amount of ice making is set by determining the loading conditions. After that, in step ST2, the present remaining ice rate X
Is calculated. This is for recognizing how much ice amount as residual ice already exists with respect to the total ice making amount calculated in step ST1 above, and for recognizing the ice making amount generated in the actual ice making operation. Then, divide the difference between the current water level and the initial water level by the difference between the set water level and the initial water level to obtain 100
Multiply by to obtain the percentage.

Then, in step ST3, it is determined whether or not the residual ice percentage X exceeds 50%. If YES, it is determined that there is a sufficient amount of residual ice, and in step ST4 the heat storage in tank B is completed. Only the heat storage expansion valve (31) of the heat exchanger (70) is closed, and ice making is performed only in the A tank (step ST5). In other words, in a situation where the amount of remaining ice is relatively large, ice formation is performed only in the A tank, which is estimated to have a small amount of remaining ice, to prevent ice blocking in the B layer, which has a large amount of remaining ice. I am trying.

On the other hand, when the residual ice rate is 50% or less in step ST3, the additional ice making rate Y is calculated in step ST6 by the following equation (1). (50−X) × 2 = Y (1) After that, in step ST7, the heat storage expansion valves (31, 31) of the heat storage heat exchangers (70, 70) located in tanks A and B are opened. Make ice in each tank. Then, while performing the ice making operation in each of the A and B tanks, the water level sensor (LS) detects the water level in the heat storage tank (60) to recognize the total amount of ice making in the heat storage tank (60). Until this water level reaches a predetermined total amount of ice making, which is the sum of the remaining ice rate X and the additional ice making rate Y,
In step ST9, the ice making operation is continuously performed in each of the A and B tanks, and when the water level reaches the predetermined total amount of ice making and it is determined to be YES, the process proceeds to step ST4 and the heat storage heat exchanger (70 (3) is closed and only the tank A is closed to make ice. Specifically, (A / 2)% in each of A and B tanks
In the situation where each ice making was done, ice making in tank B was stopped, and
Switch to ice making operation only for the tank. In other words, in a situation where the amount of residual ice in the heat storage tank (60) as a whole is small, in order to secure a sufficient amount of heat storage, ice is made in each tank, and when the total amount of ice making becomes large to a certain extent, By making ice only in the tank A, which is supposed to have a small amount of remaining ice, it is possible to prevent the formation of ice in the B layer, which has a large amount of remaining ice. Because of this heat storage operation,
The step ST5 constitutes the ice making amount control means (52).

As described above, according to the present embodiment, by preferentially performing ice making in the upstream storage chamber (6b) where the amount of remaining ice is small, a sufficient amount of heat is stored in the heat storage tank (60). It is possible to avoid the blocking of ice that occurs due to the formation of ice around the residual ice, and it is possible to smoothly melt the ice during cold heat utilization operation and improve the efficiency of extracting cold heat.

Next, the inside of the heat storage tank (60) is divided into four storage chambers (6b, 6b, ...) Of tanks A to D, and the cooling water is
The operation when the present invention is applied to an apparatus configured to flow in the order of B, C and D will be described with reference to the flowcharts of FIGS. Since the operation of steps ST11 to 13 in this flowchart is the same as the operation of steps ST1 to ST3 in the above-mentioned flowchart, the description thereof is omitted here.

If the residual ice ratio exceeds 50% in step ST13, it is determined that there is a sufficient amount of residual ice, and in step ST14, the heat storage heat exchangers (70, 70), the heat storage expansion valve (31, 31) is closed, A, B
Make ice in the tank. Chilling unit at this time (20)
The operating capacity of the compressor (21) is set to 40% (step ST15). In other words, in a situation where there is a certain amount of residual ice
Upstream A and B in which the remaining ice amount is estimated to be small in each tank
By making ice in the tank only, C and D with a large amount of residual ice
I try to prevent ice blocking in layers.

On the other hand, if NO in step ST13, that is, the remaining ice ratio is 50% or less, it is determined in step ST16 whether or not the remaining ice ratio exceeds 25%.
In this case, in step ST17, the additional ice making rate Y is calculated by the following equation (2). (50−X) × 3 = Y (2) After that, the water level sensor (LS) detects the water level in the heat storage tank (60) to recognize the total amount of ice making in the heat storage tank (60). Until the water level reaches a predetermined total amount of ice making, which is the sum of the residual ice rate X and the additional ice making rate Y, in step ST19, the heat storage expansion valve of the heat storage heat exchanger (70) located in the tank D.
Only (31) is closed and ice is made in tanks A, B and C.
At this time, the operating capacity of the compressor (21) of the chilling unit (20) is set to 70% (step ST20). Then, when it is determined to be YES when the water level has reached the predetermined total amount of ice making in step ST18, the process proceeds to step ST14 and the heat storage expansion valve (31, 31) of the heat storage heat exchanger (70, 70) located in the C and D tanks ) Is closed and ice making is performed in tanks A and B. Specifically, A, B,
When (Y / 3)% ice making is performed in each C tank, the ice making in the C tank is stopped and the ice making operation is switched to the A and B tanks.

When NO in step ST16, that is, when the residual ice rate is 25% or less, the additional ice making rate Y is calculated in step ST21 (FIG. 11) by the following equation (3). (25−X) × 4 = Y (3) After that, the water level sensor (LS) detects the water level in the heat storage tank (60) to recognize the total amount of ice making in the heat storage tank (60). Until this water level reaches a predetermined total amount of ice making, which is the sum of the remaining ice rate X and the additional ice making rate Y, in step ST23, the heat storage of the heat storage heat exchangers (70, 70, ...) Located in each tank Open the expansion valves (31, 31, ...) together and make ice in each tank. At this time, the operating capacity of the compressor (21) of the chilling unit (20) is set to 100% (step ST24).
Then, when it is determined to be YES when the water level has reached the predetermined total amount of ice making in step ST22, the process proceeds to step ST25 and only the heat storage expansion valve (31) of the heat storage heat exchanger (70) located in the tank D is closed. Make ice in tanks A, B and C. At this time, the operating capacity of the compressor (21) of the chilling unit (20) is set to 70% (step ST26). Specifically, A, B, C,
When (Y / 4)% ice making is performed in each D tank, the ice making in the D tank is stopped, and the ice making operation is switched to the A, B, and C tanks. Because of this heat storage operation, step ST
The ice quantity control means (52) is constituted by 15, 20, and 26.

As described above, even in the present embodiment, by preferentially performing ice making in the upstream storage chamber where the amount of remaining ice is small,
While ensuring a sufficient amount of heat storage in the heat storage tank (60), it is possible to avoid ice blockage that occurs due to the formation of ice around the remaining ice, and to facilitate the melting of ice during cold heat utilization operation. The efficiency of taking out cold heat can be improved by going to.

In each of the above-mentioned embodiments, the inside of the heat storage tank is divided into two or four storage chambers, but the present invention may be applied to a heat storage tank in a divided state other than these. .

The present invention is applicable not only to the direct expansion type cold water device but also to the interexpansion type cold water device.

[0052]

As described above, according to the present invention, the following effects can be obtained. According to the invention of claim 1, when the residual ice in the heat storage tank is detected after the end of the cold heat utilization operation, a predetermined amount of the ice making liquid is discharged from the heat storage tank and the heat storage tank is used for high temperature ice making. Since the liquid is supplied to melt the residual ice, it is possible to reliably prevent the blocking of ice that occurred during ice making due to the presence of residual ice as in the past, and to prevent the melting of ice during cold heat utilization operation. It can be carried out smoothly to improve the efficiency of extracting cold heat. As a result, the performance of the heat storage type cold water device can be improved.

According to the second aspect of the present invention, by equalizing the discharge amount of the ice-making liquid and the supply amount of the high-temperature ice-making liquid, the water level of the ice-making liquid in the heat storage tank is changed to that of the residual ice. Since it is changed depending only on the presence or absence of ice, it is possible to detect the presence or absence of residual ice by the water level sensor without using special residual ice detection means, and block ice while detecting the presence or absence of residual ice with a simple configuration. It can be surely prevented.

According to the third aspect of the invention, the high temperature ice-making liquid is supplied into the heat storage tank, and at the same time, the ice-making liquid is circulated between the heat storage tank and the heat load. It is possible to melt the residual ice while raising the temperature of the entire body substantially uniformly, avoid the occurrence of local residual ice, and improve the reliability of the melting operation.

According to the fourth aspect of the present invention, while the ice making liquid is circulated from the predetermined storage chamber to the other storage chamber during the cold heat utilization operation, the ice is melted, while the ice storage operation is performed in the heat storage tank during the ice making operation. Based on the amount of residual ice, the amount of ice making in the upstream storage chamber was set to be larger than the amount of ice making in the downstream storage chamber, so that ice production in the downstream storage chamber where residual ice is likely to occur is suppressed. By doing so, it is possible to avoid blocking ice in the storage chamber on the downstream side. In other words, by suppressing ice making in the storage chamber where ice blocking easily occurs, it is possible to reliably prevent ice blocking, to smoothly melt ice during cold heat utilization operation, and to improve cold heat extraction efficiency. Can be planned.

According to the fifth aspect of the present invention, when the amount of remaining ice is less than or equal to the predetermined amount, ice is made in each of the upstream storage chamber and the downstream storage chamber until the total ice making amount becomes equal to or more than the predetermined amount, and the remaining ice is left. When the amount of ice reaches a predetermined amount, ice is made only in the upstream storage chamber so that the amount of ice production in the upstream storage chamber becomes larger than the amount of ice production in the downstream storage chamber. It is possible to perform ice making to the extent that ice blocking does not occur in the downstream storage chamber, and it is possible to avoid ice blocking while ensuring a sufficient amount of heat storage in the heat storage tank as a whole.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an invention according to claim 1;

FIG. 2 is a diagram showing a configuration of an invention according to claim 4;

FIG. 3 is a refrigerant piping system diagram of the heat storage type cold water device according to the embodiment.

FIG. 4 is a water piping system diagram of the heat storage type cold water device.

FIG. 5 is a cross-sectional view showing the internal structure of the heat storage tank.

FIG. 6 is a diagram for explaining a residual ice melting operation in the first embodiment.

FIG. 7 is a diagram showing changes in tank temperature, water level, and water temperature during cooling operation.

FIG. 8 is a diagram showing changes in tank temperature and residual ice amount during cooling operation.

FIG. 9 is a flowchart showing a two-tank type ice making operation in the second embodiment.

FIG. 10 is a diagram showing a part of a flowchart showing a four-tank type ice making operation in the second embodiment.

FIG. 11 is a diagram showing a part of a flowchart showing a four-tank type ice making operation in the second embodiment.

FIG. 12 is a diagram showing a conventional ice melting operation for preventing ice from blocking.

FIG. 13 is a diagram for explaining a conventional ice making operation for preventing ice from blocking.

[Explanation of symbols]

 (10) Heat storage type cold water system (31) Heat storage expansion valve (fluid adjusting means) (51) Residual ice melting control means (52) Ice making amount control means (60) Heat storage tank (6a) Storage chamber (6d) Drain pipe (6P ) Make-up water pipe (molten liquid supply means) (7a) Heat transfer pipe (W) Cooling water (liquid for ice making) (I) Ice

Claims (5)

[Claims] 1. A heat storage tank (60) for storing an ice making liquid (W)
And a heat transfer tube (7a) immersed in the ice-making liquid (W), the heat exchange fluid is circulated through the heat transfer tube (7a) during ice making operation, and the heat exchange fluid and ice making Heat is exchanged with the liquid (W), the liquid for ice making (W) is cooled to below the freezing point, and the heat transfer tube (7
Cold heat is stored in the heat storage tank (60) by performing ice making on the outer peripheral surface of a), and during the operation utilizing cold heat, the ice making liquid (W) is circulated between the heat storage tank (60) and the heat load. In the heat storage type cold water device in which the ice (I) in the heat storage tank (60) is melted by this ice-making liquid (W) to take out cold heat, the residual ice in the heat storage tank (60) is detected. Residual ice detection means (LS)
A liquid discharging means (6d) for discharging the ice making liquid (W) from the heat storage tank (60), and an ice making liquid (W having a higher temperature than the ice making liquid (W) in the heat storage tank (60). ') For supplying molten liquid into the heat storage tank (60)
(6P), and when the residual ice detection means (LS) detects residual ice in the heat storage tank (60) after the end of the cold heat utilization operation, a predetermined amount of ice-making liquid (W) is discharged from the heat storage tank (60). Liquid discharge means (6
d) is controlled, and the above-mentioned high temperature ice-making liquid is stored in the heat storage tank (60).
A heat storage type cold water device comprising: a residual ice melting control means (51) for controlling the melted liquid supply means (6P) so as to supply (W ′). 2. A water level sensor for detecting residual ice when the residual ice detecting means detects the water level of the ice making liquid (W) in the heat storage tank (60) and when the water level is equal to or higher than a predetermined water level. (LS), the discharge amount of the ice-making liquid (W) by the liquid discharge means (6d) and the supply amount of the high-temperature ice-making liquid (W ') by the melting liquid supply means (6P) are equal to each other. It is set, The claim 1 characterized by the above-mentioned.
Heat storage type cold water device described. 3. The residual ice melting control means (51) supplies the high temperature ice-making liquid (W ') into the heat storage tank (60) by the melted liquid supply means (6P) and at the same time as the heat storage tank (60). The heat storage type cold water device according to claim 1 or 2, wherein the ice-making liquid (W, W ') is circulated between the heat storage device and the heat load. 4. A heat storage tank (6) having a plurality of storage chambers (6b, 6b ', ...) And storing the ice making liquid (W) in each storage chamber (6b, 6b', ...).
0), the heat transfer tubes (7a, 7a ', ...) which are immersed in the ice making liquid (W) in the storage chambers (6b, 6b', ...) and through which the heat exchange fluid flows, and the heat transfer tubes. (7a, 7a ', ...) is provided with fluid adjusting means (31, 31, ...) for adjusting the flow rate of the heat exchange fluid, and each of the heat transfer tubes (7a, 7a', ...) is connected to the above heat transfer tubes during ice making operation. A heat exchange fluid is circulated to perform heat exchange between the heat exchange fluid and the ice-making liquid (W), and the ice-making liquid (W) is cooled to below the freezing point to obtain heat transfer tubes (7a, 7a). ',…) Is used to store cold heat in the heat storage tank (60) by making ice on the outer peripheral surface, and when the cold heat utilization operation is performed, a predetermined storage chamber (6b) is changed to another storage chamber (6).
The ice-making liquid (W) is circulated between the heat storage tank (60) and the heat load while sequentially flowing the ice-making liquid (W) toward b '), and the ice-making liquid (W) ) Melt heat storage tank (60)
In a heat storage type cold water device for extracting cold heat from inside, residual ice amount detecting means for detecting the amount of residual ice in the heat storage tank (60)
(LS) and the ice making amount in the upstream storage chamber (6b) based on the remaining ice amount in the heat storage tank (60) detected by the above-mentioned remaining ice amount detecting means (LS) during the ice making operation. Storage type cold water characterized by being provided with an ice making amount control means (52) for controlling the fluid adjusting means (31, 31, ...) so that the amount of ice making becomes larger than the ice making amount in the storage chamber (6b '). apparatus. 5. The ice-making amount control means (52) is provided with an upstream storage chamber when the amount of remaining ice in the entire heat storage tank (60) is equal to or greater than a predetermined amount.
Fluid adjustment means (31, 3)
1, ...) while the remaining ice amount is less than or equal to the predetermined amount, the upstream storage chamber (6b) and the total ice making amount, which is the sum of the remaining ice amount and the ice making amount, becomes equal to or more than the predetermined amount. Downstream storage chamber (6
b ') The heat storage type cold water apparatus according to claim 4, wherein the fluid adjusting means (31, 31, ...) is controlled so that the same amount of ice making is performed in each unit.