JPH04227447A - Icemaker - Google Patents

Abstract

PURPOSE:To prevent damage of an icemaker in generating slurrylike iced material in a heat exchanger of a water circulation passage due to freezing of the exchanger. CONSTITUTION:Water, etc., of an ice reservoir 5 is circulated to a water circulation passage 51, and supercooled by a water heat exchanger 22. When a rising chamber of an output water temperature of the exchanger 22 becomes larger than a predetermined value, it is decided that the exchanger 22 is frozen. Thus, partial freezing in the exchanger 22 can be accurately sensed, freezing of the exchanger 22 is eliminated by cooling capacity control means 102 before the exchanger 22 is entirely frozen to be able to take preventive means. The freezing of the exchanger can be sensed even by an evaporating temperature of refrigerant for cooling the exchanger 22, a flow rate of the passage 51. Further, it can be accurately sensed by sensing it by a noncontact sensor such as a light permeability sensor, etc., without eliminating supercooling state of water, etc.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to an ice making device in which water, etc. in an ice storage tank is circulated through a water circulation path, supercooled in a heat exchanger, and then frozen products are produced, and in particular, Regarding measures for early detection of freezing.

0002

[Prior Art] Conventionally, for example, Utility Model Application Publication No. 1-13683
As disclosed in Publication No. 0, a water circulation path for circulating water in an ice storage tank, a heat exchanger provided at the outlet end of the water circulation path for supercooling the water, and a heat exchanger for supercooling the water by the heat exchanger. In an ice making apparatus equipped with a predetermined mechanism for eliminating the supercooled state of the water and producing a slurry-like frozen product, a heat insulating layer is provided on the heat transfer tube of the heat exchanger to prevent condensation. established,
A known technique attempts to prevent damage to the heat exchanger due to freezing of water inside the heat exchanger by maintaining the temperature of the inner wall of the heat exchanger tube within a predetermined range (-5.8 to 0°C).

0003

[Problem to be Solved by the Invention] However, since the water inside the heat exchanger is supercooled to a low temperature below the freezing temperature, even if the temperature of the heat exchanger tubes is controlled, mechanical shocks such as vibrations and Even if a thermal shock such as a sudden temperature change occurs, it can be used as a trigger to eliminate the supercooled state of the water. Then, when ice nuclei are generated and adhere to the tube wall,
From there, ice crystals grow and eventually the entire heat exchanger tube inside the heat exchanger may freeze and be damaged. In addition, even if it is not damaged, the cooling efficiency deteriorates.

[0004] Therefore, it is not possible to effectively detect the possibility of freezing inside the heat exchanger by simply controlling the temperature of the heat exchanger tubes, as in the conventional method described above, and therefore effective antifreeze measures must be taken. The problem was that I couldn't do it.

[0005] The present invention has been made in view of the above, and its object is to prevent the freezing of water or aqueous solution when the supercooled state inside the heat exchanger is resolved for some reason and the water or aqueous solution partially freezes. By focusing on the fact that the change in the state quantity of water, etc. shows a unique change that is different from normal, and by accurately detecting the partially frozen state of water, etc. from the change in the state quantity, it is possible to improve the temperature of the heat exchanger. The purpose is to make it possible to prevent complete freezing.

[0006]

[Means for solving the problem] In order to achieve the above object, the first solution is as shown in Fig. 1 (solid line only).
, an ice storage tank (5) for storing frozen slurry of water or an aqueous solution, a water heat exchanger (22) connected to a cooling device for supercooling the water or an aqueous solution, and a water heat exchanger (22) for supercooling the water or the aqueous solution. An ice making apparatus is assumed to be provided with a water circulation path (51) for forcedly circulating water or an aqueous solution between a heat exchanger (22) and the ice storage tank (5).

[0007] Water temperature detection means (Th
w) and the output of the water temperature detection means (Thw), when the increase in the outlet temperature of the water or aqueous liquid is larger than a predetermined value, the water or aqueous solution inside the water heat exchanger (22) partially This configuration includes a determining means (101A) for determining that the frozen state is frozen.

In a second solution, the cooling device in the first solution is a refrigerant circuit (1) of a refrigeration device.

As shown in FIG. 1 (including the broken line portion), there is a water temperature detection means (Thw) for detecting the temperature of the water or aqueous solution at the outlet of the water heat exchanger (22), and a An evaporation temperature detection means (Pe) detects the evaporation temperature of the refrigerant at the outlet of the water heat exchanger (22), and receives the outputs of the water temperature detection means (Thw) and the evaporation temperature detection means (Pe), and receives the output of the water or aqueous solution at the outlet of the water or aqueous solution. determining means (101B) for determining that the water or aqueous solution inside the water heat exchanger (22) is partially frozen when the increase change in the difference between the temperature and the evaporation temperature of the refrigerant is larger than a predetermined value; The structure is such that it is provided.

[0010] A third solution, as shown by the dotted line in FIG. A means (Fm) is provided.

[0011] The determination means (101) is then used to determine whether the water heat exchanger (22)
It is determined that the water or aqueous solution inside is partially frozen.

The fourth solution includes an ice storage tank (5) for storing a slurry-like frozen product of water or an aqueous solution, and a hydrothermal tank (5) connected to a cooling device for supercooling the water or an aqueous solution. an exchanger (22), the water heat exchanger (22) and the ice storage tank (
5) and a water circulation path (51) for forced circulation of water or an aqueous solution.

[0013] A non-contact sensor that detects information related to the freezing of water or an aqueous solution at the outlet of the water heat exchanger (22) without contacting the water or the aqueous solution, and an amount of information detected by the non-contact sensor. Based on this, a determining means (101C) is provided for determining that the water or aqueous solution inside the water heat exchanger (22) is partially frozen.

[0014] As shown in the dot-dash line in FIG. The cooling capacity control means (102) is provided to control the supercooling capacity of the water heat exchanger (22) so as to eliminate the partially frozen state of water or aqueous solution inside the exchanger (22).

The sixth solution is as shown in FIG.
An ice storage tank (5) for storing a slurry-like frozen product of water or an aqueous solution, a water heat exchanger (22) for supercooling the water or an aqueous solution, and the water heat exchanger (22). Above ice storage tank (
5) for forced circulation of water or an aqueous solution between the water circulation path (51) and the water heat exchanger (2) of the water circulation path (51).
2) It is assumed that the ice making device is equipped with a preheating heat exchanger (6) that is arranged on the upstream side and preheats the water or aqueous solution supplied to the water heat exchanger (22), and the ice making device is equipped with a compressor. (11)
, (21), heat source side heat exchanger (12), heat source side pressure reducing valve (
13), pressure reducing valve for ice making (23) and the water heat exchanger (2)
2), a switching mechanism (2) that switches the gas pipe of the heat source side heat exchanger (12) to selectively communicate with the discharge line and the suction line, and the preheating heat Bypass means (105) for introducing a heating refrigerant such as water or an aqueous solution from the refrigerant circuit into the refrigerant flow section of the exchanger (6).
) shall be provided.

[0016] During ice making operation in the water heat exchanger (22), a freeze detection means for detecting the frozen state of the water or aqueous solution inside the water heat exchanger (22), and a freeze detection means for receiving the output of the freeze detection means are provided. When the inside of the water heat exchanger (22) freezes, the switching mechanism (2) is switched to connect the gas pipe of the heat source side heat exchanger (12) to the suction line, and the preheating heat exchanger (6) ) is provided with a thawing operation control means for controlling the bypass means (105) to increase the heating capacity.

The seventh solution is as shown in FIG.
An ice storage tank (5) for storing a slurry-like frozen product of water or an aqueous solution, a water heat exchanger (22) for supercooling the water or an aqueous solution, and the water heat exchanger (22). Above ice storage tank (
5) for forced circulation of water or an aqueous solution between the water circulation path (51) and the water heat exchanger (2) of the water circulation path (51).
2) It is assumed that the ice making device is equipped with a preheating heat exchanger (6) that is arranged on the upstream side and preheats the water or aqueous solution supplied to the water heat exchanger (22), and the ice making device is equipped with a compressor. (11)
, (21), outdoor heat exchanger (12), outdoor pressure reducing valve (13)
), a refrigerant circuit (1) formed by sequentially connecting an indoor pressure reducing valve (33) and an indoor heat exchanger (32), a switching mechanism (2) for switching between forward and reverse refrigeration cycles of the refrigerant circuit (1), and the above-mentioned The inlet side of the refrigerant flow part of the water heat exchanger (22) is connected to the outdoor pressure reducing valve (13) of the refrigerant circuit (1) via the ice making pressure reducing valve (23).
- An ice making bypass passage (24) connecting the outlet side to the suction line, respectively, to the liquid pipe between the indoor pressure reducing valve (33), and the refrigerant circuit (1) to the refrigerant flow part of the preheating heat exchanger (6). Bypass means for introducing water or aqueous solution heating refrigerant (
105) shall be provided.

[0018] During ice making operation in the water heat exchanger (22), a freeze detection means for detecting the frozen state of water or aqueous solution inside the water heat exchanger (22), and a freeze detection means that receives the output of the freeze detection means. When the inside of the water heat exchanger (22) freezes, the switching mechanism (2) is switched so that the indoor heat exchanger (32) becomes an evaporator, and the heating capacity of the preheating heat exchanger (6) is increased. The above bypass means (
105).

The eighth solution is as shown in FIG.
An ice storage tank (5) for storing a slurry-like frozen product of water or an aqueous solution, a water heat exchanger (22) for supercooling the water or an aqueous solution, and the water heat exchanger (22). Above ice storage tank (
5) for forced circulation of water or an aqueous solution between the water circulation path (51) and the water heat exchanger (2) of the water circulation path (51).
2) It is assumed that the ice making device is equipped with a preheating heat exchanger (6) that is arranged on the upstream side and preheats the water or aqueous solution supplied to the water heat exchanger (22), and the ice making device is equipped with a compressor. (11)
, (21), indoor heat exchanger (12), outdoor pressure reducing valve (13)
), an indoor pressure reducing valve (33), and an indoor heat exchanger (32) are sequentially connected to the refrigerant circuit (1), and the outdoor heat exchanger (
12) and an outdoor switching mechanism (2) and an indoor switching mechanism (36) that switch the gas pipes of the indoor heat exchanger (32) to selectively communicate with the discharge line and the suction line, respectively;
The inlet side of the refrigerant flow part of the water heat exchanger (22) is connected to the outdoor pressure reducing valve (
13) An ice-making bypass passage (24) connecting the outlet side to the suction line is connected to the liquid pipe between the indoor pressure reducing valve (33), and the refrigerant circuit ( Bypass means (105) for introducing a heating refrigerant such as water or an aqueous solution from 1) shall be provided.

[0020] During ice making operation in the water heat exchanger (22), a freeze detection means for detecting the frozen state of the water or aqueous solution inside the water heat exchanger (22), and a freeze detection means for receiving the output of the freeze detection means are provided. , when the inside of the water heat exchanger (22) freezes, the outdoor heat exchanger (12) and the indoor heat exchanger (
The switching mechanisms (2) and (36) are switched so that the gas pipe (32) is communicated with the suction line, and the bypass means (105) is controlled to increase the heating capacity of the preheating heat exchanger (6). A defrosting operation control means is provided.

A ninth solution is that in the sixth, seventh, or eighth solution, the ice-making pressure reducing valve (23) has a flow rate adjustment function, and the thawing operation control means controls the ice-making operation during the thawing operation. The pressure reducing valve (23) is controlled to close.

[0022] A tenth solution is the sixth, seventh or eighth solution, in which a water temperature detection means (Thw) is provided for detecting the temperature of the water or aqueous solution at the outlet of the water heat exchanger (22). The ice making pressure reducing valve (23) has a flow rate adjustment function, and the thawing operation control means receives the output of the water temperature detecting means (Thw) and closes the ice making pressure reducing valve (23) at the start of the thawing operation. Then, when the temperature of the water or aqueous solution at the outlet of the water heat exchanger (22) reaches a predetermined value or higher, the ice-making pressure reducing valve (23) is controlled to be opened.

An ice making device characterized by:

[0024] An eleventh solution is the sixth, seventh, or eighth solution, which is provided with a timer for measuring the elapsed time after the thawing operation is started by the thawing operation control means. The ice-making pressure reducing valve (23) is configured to have a flow rate adjustment function, and the thawing operation control means receives the output of the clocking means and controls the ice-making pressure reducing valve (23) at the start of the thawing operation.
After the ice making pressure reducing valve (23) is closed, when the elapsed time after the start of the thawing operation reaches a certain time, the ice making pressure reducing valve (23) is controlled to be opened.

[0025]

[Operation] With the above structure, in the invention of claim 1, the water or aqueous solution in the ice storage tank (5) is cooled by the cooling device via the water heat exchanger (22) in the water circulation path (51) to a supercooled state. become.

[0026] In this case, when water or the like partially freezes inside the water heat exchanger (22), the water temperature rises due to the generation of heat of solidification. Here, in the present invention, water temperature detection means (Thw
), when the increase in the outlet temperature of the water, etc. detected by the determination means (101A) determines that the water, etc. in the water heat exchanger (22) is partially frozen. Therefore, a partially frozen state of water or the like can be accurately detected before the interior of the water heat exchanger (22) completely freezes and causes damage.

In the invention of claim 2, the water heat exchanger (22)
When the water is supercooled by heat exchange with the refrigerant in the refrigerant circuit (1) of the refrigeration system, if the water etc. partially freezes inside the water heat exchanger (22), the water temperature detection means (Thw) While the detected outlet temperature of water or the like increases, the evaporation temperature of the refrigerant detected by the evaporation temperature detection means (Pe) decreases.

Therefore, the difference between the outlet temperature of water, etc. and the evaporation temperature of the refrigerant increases. However, in the present invention, when the increase in the difference between the two exceeds a predetermined value, the determining means (101B ), it is determined that the water, etc. is partially frozen, so that the partially frozen state of the water, etc. can be detected more accurately before the water heat exchanger (22) completely freezes. become.

[0029] In the invention of claim 3, the above-mentioned claim 1 or 2
In the operation of the invention, the determination means (101) makes a determination of freezing by taking into account the decrease in flow rate due to partial freezing of water, etc. inside the water heat exchanger (22). The frozen state will be detected more accurately.

In the invention of claim 4, information related to the frozen state of water, etc. at the outlet of the water heat exchanger (22) detected by the non-contact sensor is detected, and the determination means (101C) determines based on this information. It is determined whether water, etc. has frozen. In other words, when trying to detect the frozen state of water, etc. with a normal temperature sensor, the detection part of the sensor is exposed to the flow of water, etc., so the flow of water is disturbed by the sensor, wiring, etc., and the supercooling state is eliminated. However, in the present invention, since information related to freezing of water, etc. can be obtained using a non-contact sensor, the frozen state can be detected with high accuracy without affecting the supercooled state of water, etc.

[0031] In the invention of claim 5, the above-mentioned claims 1, 2,
In addition to the effects of the third or fourth invention, when the determination means (101) determines that the water etc. inside the water heat exchanger (22) is partially frozen, the cooling capacity control means (10
2), the supercooling capacity of the water heat exchanger (22) for water, etc. is controlled so that the water heat exchanger (22) is thawed before the water heat exchanger (22) completely freezes. ) and a decrease in cooling efficiency.

According to the invention of claim 6, during ice making operation, ice cores such as water are melted by the preheating heat exchanger (6) in the water circulation path (51), and water etc. are heated by the water heat exchanger (22). It is cooled and an ice-making action is performed to produce a slurry-like frozen product.

At this time, if the freezing state of the water heat exchanger (22) is detected by the freezing detection means during the ice making operation, the thawing operation control means increases the heating capacity of the preheating heat exchanger (6). Since the bypass means (105) is controlled, in the water circulation path (51), the water, etc. is cooled by the water heat exchanger (22), and the water heat exchanger (22) is thawed due to the rise in water temperature upstream. Compared to the case where the water heat exchanger (22) is directly heated, an increase in the outlet water temperature of the water heat exchanger (22) is suppressed, heat loss is reduced, and operating efficiency is improved.

On the other hand, on the refrigerant circuit side, the heat source side heat exchanger (
12) is controlled so that the refrigerant circulates in the refrigeration cycle which serves as an evaporator, so the increase in heating capacity of the preheating heat exchanger (6) is offset by the heat source side heat exchanger (12), resulting in smooth refrigerant circulation. is ensured.

According to the seventh aspect of the invention, during the ice making operation, the same ice making effect as in the sixth aspect of the invention can be obtained.

At this time, when freezing of the water heat exchanger (22) is detected by the freezing detection means, the thawing operation control means operates the bypass means (105) to increase the heating capacity of the preheating heat exchanger (6). is controlled, the water circulation path (5
In 1), the water heat exchanger (22) is thawed by the same effect as the invention of claim 6, and the operating efficiency is improved by reducing heat loss.

On the other hand, on the refrigerant circuit (1) side, the refrigerant is circulated in the refrigeration cycle in which the indoor heat exchanger (32) acts as an evaporator under the control of the thawing operation control means, so that direct indoor cooling using the refrigerant is possible. It becomes possible.

According to the invention of claim 8, during the ice making operation, the same ice making effect as in the invention of claim 6 can be obtained.

At this time, when freezing of the water heat exchanger (22) is detected by the freezing detection means, the thawing operation control means operates the bypass means (105) to increase the heating capacity of the preheating heat exchanger (6). is controlled, the water circulation path (5
In 1), the water heat exchanger (22) is thawed by the same effect as the invention of claim 6, and the operating efficiency is improved by reducing heat loss.

On the other hand, on the refrigerant circuit (1) side, the refrigerant circulates in a refrigeration cycle in which both the outdoor heat exchanger (12) and the indoor heat exchanger (32) become evaporators under the control of the thawing operation control means. , the condensing capacity of the preheating heat exchanger (6) is improved compared to the invention of claim 7.

According to the ninth aspect of the invention, since the ice making pressure reducing valve (23) is closed by the thawing operation control means during the thawing operation, compared to the case where the water heat exchanger (22) is used as a condenser and thawing is performed directly. Therefore, the temperature near the pipe wall does not rise so much, and when ice-making operation is resumed after thawing, ice-making starts quickly.

In the invention of claim 10 or 11, the ice making pressure reducing valve (23) is closed at the start of the thawing operation, and when the water temperature at the outlet of the water heat exchanger (22) reaches a predetermined temperature or higher, or after a certain period of time. Since the ice-making pressure reducing valve (23) is opened when the ice-making time has elapsed, the thawing operation time is shortened, and
Heat loss will be reduced.

[0043]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIG. 2 and subsequent drawings.

FIG. 2 shows the configuration of the refrigerant circuit (1) of the air conditioner of the first embodiment, in which (11) is the first compressor, (12)
) is an outdoor heat exchanger that is arranged on the discharge side of the first compressor (11) and exchanges heat between the refrigerant and outdoor air, and (13) adjusts the refrigerant flow rate of the outdoor heat exchanger (12). , or an outdoor electric expansion valve that reduces pressure, which includes each of the above devices (11) to (
13) are connected in series in the first conduit (14).

Further, (21) is a second compressor, (22) is a water heat exchanger as a main heat exchanger for supercooling the water or aqueous solution in the ice storage tank (5), which will be described later, (23) is a water-side electric expansion valve as an ice-making pressure reducing valve that adjusts the flow rate of refrigerant when the water heat exchanger (22) functions as a condenser, and reduces the pressure of the refrigerant when it functions as an evaporator; The devices (21) to (23) are connected in series in the second conduit (24).

Note that (SD1) and (SD2) are oil separators installed in the discharge pipes of the compressors (11) and (21), respectively, and (C1) and (C2) are the oil separators (S
D1 ), (SD2 ) to each compressor (11), (21
) Oil return pipes (RT1) installed on the suction side of each
, (RT2), respectively, are decompression capillary tubes.

Further, (32) and (32) are indoor heat exchangers placed in each room, and (33) and (33) are indoor electric units that reduce the pressure of the refrigerant during cooling operation and adjust the refrigerant flow rate during heating operation. An expansion valve, each of the above devices (32), (3
3) are connected in series, and each set is connected to the third pipe line (
34) are connected in parallel inside. In other words, the second
The pipe line (24) serves as an ice-making bypass line for the refrigerant circuit for air conditioning operation formed by the first and third pipe lines (14) and (34).

[0048] The first pipe line (14) and the second pipe line (24) are connected in parallel to the third pipe line (34), forming a closed circuit in which the refrigerant circulates. In addition, (A
c) is an accumulator provided on the suction side of each compressor (11), (21).

In addition, (2) connects the gas pipes of the outdoor heat exchanger (12) and the gas pipes of the indoor heat exchangers (32), (32) to the discharge side of each compressor (11), (21) or It is a four-way switching valve that switches to alternately communicate with the suction side, and when the four-way switching valve (2) switches to the solid line side in the figure, the outdoor heat exchanger (12) is switched to the condenser and the indoor heat exchanger. (32), (32
) functions as an evaporator and performs cooling operation indoors,
When the four-way selector valve (2) switches to the broken line side in the figure, the outdoor heat exchanger (12) switches to the evaporator, the indoor heat exchanger (32),
(32) functions as a condenser and performs heating operation indoors.

Furthermore, a branch line (25) bypass-connecting the gas pipe of the water heat exchanger (22) and the suction pipe of each compressor (11), (21), and A water side switching valve (26) is provided for selectively communicating the gas pipe with the discharge pipe of the second compressor (21) and the branch path (25). The water side switching valve (26) uses three ports of the four-way switching valve, and when the water side switching valve (26) switches to the solid line side in the figure, the water heat exchanger (22) ) gas pipe is on the branch path (25) side, that is, each compressor (11), (21)
The water heat exchanger (22) functions as an evaporator, while the gas pipe of the water heat exchanger (22) is connected to the suction side of the water heat exchanger (22) when the water side switching valve (26) is switched to the broken line side in the figure. The water heat exchanger (22) is connected to the discharge pipe of the second compressor (21) and functions as a condenser. In addition, (C3
) is a capillary tube installed in the pipe on the dead port side of the water side switching valve (26).

Furthermore, a bypass passage (3) is provided that connects the discharge pipes of the first compressor (11) and the second compressor (21). (
A check valve (4) is provided that allows refrigerant to flow only from the discharge pipe side of the first compressor (11) to the discharge pipe side of the first compressor (11).

That is, when the outdoor heat exchanger (12) and the water heat exchanger (22) function as condensers, if the condensation temperature in the water heat exchanger (22) becomes high and the pressure becomes high, the second compression The discharge gas from the machine (21) is transferred to the outdoor heat exchanger (12).
) side, the amount of heat dissipated can be distributed.

[0053] Here, the air conditioner is provided with an ice storage tank (5) for storing a slurry-like frozen product of water or an aqueous solution as a heat storage medium, and the ice storage tank (5) and the water heat exchanger (22) are connected by a water circulation path (51) so that water or an aqueous solution can be circulated therebetween. The water circulation path (
51) is a water heat exchanger (22) from the bottom of the ice storage tank (5).
an outgoing pipe (51A) that supplies water, etc. to the water heat exchanger (2
It consists of a return pipe (51B) that returns frozen material in the form of slurry such as water from 2) to the top of the ice storage tank (5), and an outbound pipe (51B)
The water or aqueous solution in the ice storage tank (5) is forced to circulate within the water circulation path (51) by a pump (52) installed in the ice storage tank (51A).

[0054] Note that the outgoing pipe (51A) of the water circulation route (51)
) A strainer (53) is provided downstream of the pump (52) for removing solid matter such as frozen matter or dust from the water or aqueous solution in the water circulation path (51). Na(
A preheating heat exchanger (6) that preheats water and the like supplied to the water heat exchanger (22) is provided downstream of the water heat exchanger (53). On the other hand, the liquid line of the refrigerant circuit (1) is provided with a preheating bypass passage (61) that allows a part of the liquid refrigerant to bypass the water side electric expansion valve (23) and flow to the preheating heat exchanger (6). and a preheating heat exchanger (6) of the preheating bypass path (61).
A preheating electric expansion valve (62) having a refrigerant pressure reduction function and a flow rate control function is provided on the downstream side of the refrigerant. With the preheating electric expansion valve (62) and the water side electric expansion valve (23),
The refrigerant flow rate in the preheating bypass passage (61) is adjusted, and the pressure of the refrigerant is also reduced during the ice-making operation of the water heat exchanger (22).

[0055] Then, the return pipe (
51B), on the downstream side of the water heat exchanger (22),
The water in the return pipe (51B) is cooled and transferred to the water heat exchanger (22).
A recooler (8) is provided as a supercooling eliminating section that eliminates the supercooled state of water, etc. that has been supercooled in the water. is provided with a heat-retaining heat exchanger (7) as a freeze progress prevention unit for preventing freezing of the return pipe (51B) from progressing to the water heat exchanger (22).

[0056] Furthermore, the second compressor (
A heat-retaining bypass passage (71) is provided for bypassing and circulating hot gas from the discharge pipe 21) to the heat-retaining heat exchanger (7) and returning it to the suction side. On the other hand, a recooling bypass path (81) is provided for bypassing the refrigerant from the liquid line of the refrigerant circuit (1) to the branch path (25) that becomes the suction side of the compressors (11), (21), A recooling capillary tube (C4) and a recooler (8) are sequentially provided in the recooling bypass path (81) from the upstream side.

That is, in the recooler (8), the water etc. supercooled in the water heat exchanger (22) is regenerated by heat exchange with the low temperature refrigerant whose pressure has been reduced in the recooling capillary tube (C4). The supercooled state is removed, the slurry is frozen, and the frozen slurry is circulated to the ice storage tank (5) via the return pipe (51B). In (7), the return pipe (51B) is heated by heat exchange with a relatively high-temperature liquid refrigerant, and the supercooling of water, etc. is eliminated in the recooler (8) and the return pipe (51B). This is to prevent frozen products from adhering to the pipe wall of the return pipe (51B) and from progressing to the water heat exchanger (22).

Here, as a feature of the present invention, the refrigerant circuit (
1) of the second compressor (21) and the water heat exchanger (22)
A hot gas bypass passage (91) is provided which connects the hot gas bypass passage (91) to the liquid pipe (91), and a hot gas opening/closing valve (92) for opening and closing the passage is interposed in the hot gas bypass passage (91). That is, when the hot gas on-off valve (92) is closed, each electric expansion valve (23) is connected to the water heat exchanger (22).
), (62) to circulate only the low-temperature refrigerant decompressed, while when the hot gas on-off valve (92) opens, the hot gas discharged from the second compressor (21) is sent to the water heat exchanger (22). It is designed to be mixed in.

[0059] Various sensors are installed in the air conditioner, and (Thw) is placed at the outlet of the water heat exchanger (22) of the return pipe (51B). A temperature sensor (Pe) serves as a water temperature detection means for detecting the temperature of water, etc. at the outlet, and (Pe) is a water heat exchanger (
22) is arranged on the gas pipe side, and is a pressure sensor as an evaporation temperature detection means that detects the saturation temperature (evaporation temperature) corresponding to the evaporation pressure of the refrigerant in the water heat exchanger (22) from the low pressure side pressure value during ice making operation. be. And each of the above sensors (
Thw) and (Pe) are connected by signal lines to a controller (not shown) that controls the operation of the device, and the controller controls the signals according to the signals from each sensor (Thw) and (Pe). It is designed to control the operation of the air conditioner.

[0060] When the air conditioner is operated to perform cooling operation indoors, the four-way selector valve (2) is switched to the solid line side in the figure. When the water side switching valve (26) is switched to the solid line side in the figure, each compressor (11), (21)
After the refrigerant discharged from the refrigerant is condensed in the outdoor heat exchanger (12), it is evaporated in each of the indoor heat exchangers (32) and (32), thereby cooling the room. In addition, the water side switching valve (
26) is switched to the broken line side in the figure, the first
The refrigerant discharged from the compressor (11) flows to the outdoor heat exchanger (12), while the refrigerant discharged from the second compressor (21) flows to the water heat exchanger (22), and after being condensed, the refrigerant is transferred to each indoor heat exchanger. The liquid is circulated through the vessels (32) and (32) to evaporate it.

[0061] Furthermore, when electricity is cheap, such as at night, a cold storage heat operation is performed in which cold heat is stored in the ice storage tank (5). That is, the four-way switching valve (2) and the water side switching valve (26) are switched to the solid line side in the figure, and each indoor electric expansion valve (33), (33)
is closed and the refrigerant discharged from each compressor (11), (21) is condensed in the outdoor heat exchanger (12), and then the water side electric expansion valve (2) is closed.
3) (or the preheating electric expansion valve (62)) and evaporates it in the water heat exchanger (22), thereby supercooling the water or aqueous solution in the ice storage tank (5) and turning it into an ice storage tank (5). It is designed to freeze water, etc., and store cold energy.

[0062] At this time, the above-mentioned controller performs antifreeze control of the water heat exchanger (22). First, regarding the control content according to the invention of claim 1, the flowchart of FIG.
To explain based on the above, in step S1, the value Two of the outlet water temperature detected by the temperature sensor (Thw) is input, and in step S2, the change ΔTwo in the outlet water temperature is calculated as ΔTwo=Two−Two′ (however, Two' is determined from the value of the outlet water temperature at the time of the previous sampling. Then, in step S3, an increase change value A of the outlet water temperature is determined by setting A=ΔTwo/Δt (where Δt is the sampling interval).

Next, in step S4, it is determined whether or not the value of this increase change value A is larger than a predetermined reference value Ao set in advance, and the increase change value A of the outlet water temperature is determined to be greater than the reference value Ao.
o If it is below, it is determined that there is no risk of freezing of the water, etc., and the process proceeds to step S5, where the outlet water temperature value Two is updated, and then the process returns to the main control routine in step S6. When the water temperature increase change value A is larger than the reference value Ao, the process moves to step S7, and the water heat exchanger (
22) It is determined that the water etc. inside is partially frozen. Furthermore, in step S8, the hot gas on-off valve (92) is opened for a certain period of time to transfer the hot gas to the water heat exchanger (
A thawing operation of the water heat exchanger (22) introduced into the water heat exchanger (22) is performed.

In the above flow, the control in step S7 constitutes a determining means (101A) that determines that the water, etc. inside the water heat exchanger (22) is partially frozen.

Therefore, in the invention of claim 1, after the water etc. in the ice storage tank (5) is circulated through the water circulation path (51) and supercooled in the water heat exchanger (22), the water etc. is in a supercooled state. During ice making, the water heat exchanger (Thw) detects temperature sensor (water temperature detection means) (Thw).
22) The increase change value A of the outlet water temperature is the predetermined reference value Ao.
If it becomes larger than this, the determining means (101A) determines that the water, etc. inside the water heat exchanger (22) is partially frozen.

Here, as shown in FIG. 5, the water heat exchanger (
22) When frozen substances such as water occur inside (time t in the diagram)
s), the water temperature rises due to the generation of heat of solidification of water, etc., and especially when frozen substances adhere to the pipe wall and become nuclei and grow ice crystals, freezing expands. , the value Two of the outlet water temperature of the water heat exchanger (22) increases rapidly. Therefore, by setting a predetermined reference value Ao in advance from the slope of the straight line of increase in the outlet water temperature when partial freezing occurs, the entire water heat exchanger (22) can be frozen from the increase change value A of the outlet water temperature. It is possible to detect a partially frozen state before this occurs, and thereby it becomes possible to take effective antifreeze measures.

Furthermore, in the invention of claim 1, the water heat exchanger (
22) The cooling device for supercooling water etc. is the cooling device for supercooling water etc.
The present invention is not limited to the refrigerant circuit (1) of an air conditioner as in the embodiment, but it is also possible to use a circuit that directly cools heat transfer tubes, such as a thermo module.

Next, the control contents according to the invention of claim 2 will be explained based on FIG. 4. In step P1, the water heat exchanger (Thw) detected by the temperature sensor (Thw)
22) outlet water temperature value Two and the pressure sensor (Pe
) and the evaporation temperature Te of the refrigerant in the water heat exchanger (22) detected in step P2.
d is calculated by the formula Td = Two-Te. Next, in step P3, the difference ΔTd from the previous sampling
is obtained from the formula ΔTd = Td − Td ′ (
However, Td' is the difference between the outlet water temperature and the evaporation temperature during the previous sampling), and in step P4, B=Δ
An increase change value B of the difference between the outlet water temperature and the evaporation temperature is determined from Td/Δt.

Then, in step P5, it is determined whether the increased change value B obtained above is larger than a predetermined reference value Bo, and the increased change value B is determined as the reference value Bo.
If it is below, it is determined that there is no freezing of water, etc., and the process proceeds to step P6, where the difference Td between the outlet water temperature and the evaporation temperature is
After updating, the process returns to the main control routine in step P7. On the other hand, if the increase change value B is larger than the reference value Bo in the determination in step P5 above, the process moves to step P8, and it is determined that the water inside the water heat exchanger (22) is partially frozen. Further, in step P9, thawing operation control is performed to introduce hot gas from the compressor (21) into the water heat exchanger (22).

In the above flow, by the control in step P8, when the increase change value B of the difference between the outlet water temperature and the evaporation temperature is greater than or equal to the predetermined reference value Bo, the water heat exchanger (22)
A determining means (101B) is configured to determine that the water or the like inside is partially frozen.

Therefore, in the invention of claim 2, when the cooling device that cools water etc. with the water heat exchanger (22) is the refrigerant circuit (1) of an air conditioner (refrigeration device), the temperature sensor (Thw) Increase change value B of the difference between the outlet water temperature of the water heat exchanger (22) detected by the water heat exchanger (22) and the evaporation temperature of the water heat exchanger (22) detected by the pressure sensor (evaporation temperature detection means) (Pe)
is larger than the reference value Bo, the determination means (101
Based on B), it is determined that the water, etc. inside the water heat exchanger (22) is partially frozen. That is, time ts in FIG.
As shown in the figure, when water etc. freezes inside the water heat exchanger (22), the value Two of the outlet water temperature of the water heat exchanger (22) increases rapidly, while the refrigerant temperature in the water heat exchanger (22) increases rapidly. Since the evaporation temperature decreases rapidly, the difference Td between the two increases rapidly by adding the changes in both. Therefore, the increase change value B of the difference between this outlet water temperature and the evaporation temperature
By setting a predetermined reference value Bo in advance from data when water, etc. partially freezes, when the difference increase change value B exceeds the reference value Bo, the water heat exchanger (22) It is possible to accurately detect that water or the like is partially frozen inside.

Next, a second embodiment according to the third aspect of the invention will be described. FIG. 6 shows the configuration of an air conditioner in a second embodiment. In this embodiment, in addition to the configuration of the first embodiment shown in FIG.
In A), the preheating heat exchanger (6) and the strainer (53
) A flow meter (Fm) is installed as a flow rate detection means for detecting the flow rate of water or the like. The other configurations are the same as those of the first embodiment.

[0073] Here, the contents of the control for preventing freezing by the controller will be explained based on the flowchart of Fig. 7. In step R1, the pressure sensor (Pe
) The evaporation temperature Te of the refrigerant in the water heat exchanger (22) detected by the water heat exchanger (22), the value Two of the outlet water temperature of the water heat exchanger (22) detected by the temperature sensor (Thw), and the flow meter (Fm
) is input, and in step R2, the difference Td between the outlet water temperature Two and the evaporation temperature Te is calculated, and in step R3, this difference value Td is input.
and the flow rate Fw, the change values ΔTd and ΔFw from the values Td ′ and Fw ′ due to the previous sampling
After calculating, in step R4, B=ΔTd/Δ
Based on t, C=ΔFw/Δt, the change values B and C of the difference value Td and the flow rate Fw are determined.

Then, in step R5, it is determined whether the change value B of the difference between the outlet water temperature and the evaporation temperature obtained above is larger than a preset reference value B1, that is, the increase change is larger than the reference value B1. If B>B1, it is determined that there is no risk of freezing of the water heat exchanger (22), and the outlet water temperature value Two is updated in step R6, and then in step R7. Return to main control routine. On the other hand, in the case of B>B1 in the determination in step R5, it is further determined in step R8 whether or not the flow rate change value C is smaller than a predetermined reference value -Co, that is, the flow rate decrease change. is larger than a predetermined value, and if C<-Co, proceed to step R6, update the flow rate value Fw, and then proceed to step R7, and if C<-Co, proceed to step R9. In step R10, it is determined that the water inside the water heat exchanger (22) is partially frozen, and further, in step R10, a thawing operation is performed by mixing hot gas etc. as in the first embodiment. conduct.

In the above flow, steps R5 and R
In the invention according to claim 1 or 2, by the control that shifts from 8 to R9, it is determined that the inside of the water heat exchanger (22) is partially frozen, taking into account the decrease in the flow rate of water, etc. A determining means (101A or 101B) is configured.

Therefore, in the invention of claim 3, in addition to the invention of claim 1 or 2, the determination means (101A or 101B) determines whether the water circulation path ( 51), a partial frozen state of the water, etc. inside the water heat exchanger (22) is detected, taking into account the decrease in the flow rate of the water, etc. in the water heat exchanger (22). That is, at time t in FIG.
As shown in s, when frozen substances such as water are generated inside the water heat exchanger (22) and adhere to the tube walls, freezing starts from the tube walls, and the flow rate of water etc. decreases rapidly. Additionally, in shell end tube type heat exchangers, one of the tubes may freeze. Therefore, it is necessary to take measures to effectively prevent the water heat exchanger (22) from completely freezing by predicting the risk of freezing of the water heat exchanger (22) by taking into account changes in the decrease in flow rate. becomes possible.

In particular, regarding the reference value of the increase change in the difference between the outlet water temperature and the evaporation temperature, the flowchart in FIG. 4 of the first embodiment is used.
The reference value B1 in this embodiment can be set smaller than the reference value Bo in the chart. In other words,
By taking into consideration the flow rate in a later step, even if the increase in the difference between the outlet water temperature and the evaporation temperature is judged more strictly, ice making by preventing freezing even when there is no risk of freezing. without causing deterioration in efficiency,
This allows for more accurate judgments.

[0078] In the above second embodiment, the invention of claim 3 which cited the invention of claim 2 was explained, but it can be similarly applied to the case where the invention of claim 1 is cited. it is obvious.

Next, a third embodiment according to the fourth aspect of the invention will be described. Figure 8 shows the water heat exchanger (
22) Showing the structure near the outlet, a part of the water heat exchanger (22) outlet side of the return line (51B) of the water circulation line (51) includes:
Detection piping (51a) formed of a transparent resin material
), and a transmittance sensor (Ls) as a non-contact sensor for detecting the light transmittance of water or the like in a non-contact manner is provided in the detection pipe (51a). The transmittance sensor (Ls) includes a light-emitting element (Ls1) and a light-receiving element (Ls), which are respectively attached to the detection pipe (51a) facing each other.
s2), and compares the amount of light emitted from the light emitting element (Ls1) that reaches the light receiving element (Ls1) after undergoing transmission loss due to the detection piping (51a) and water flowing inside the piping. By doing so, it is possible to detect the frozen state of water, etc. In other words, as shown in Figure 9, when the transmittance when the inside of the pipe is not frozen at all is εo, when some of the water etc. freezes, the light transmittance ε decreases and reaches the set value εs. It is determined that water, etc. has frozen. FIG. 10 shows the contents of antifreeze control based on the light transmittance ε. In step T1, the light transmittance ε
Read the data, and in step T2, the previous 3
Light transmittance data in multiple measurements ε1, ε2, ε3
The average value εm (εm = (ε1 +ε2 +ε3
)/3, and in step T3, the current light transmittance value ε detected in step T1 is set to the average value εm of the past three measured values calculated in step T2 with a constant α (0<α<
1), and determine whether it is smaller than the product multiplied by ε<α
・Proceed to step T4 until εm is reached, and ε1
After updating the measured values as follows: =ε, ε2 =ε1, ε3 =ε2, the process returns to the main control routine at step T5.

On the other hand, in the determination at step T3 above, ε<
When α·εm is reached, the process proceeds to step T6, where it is determined that the water heat exchanger (22) has frozen, and in step T7, the water heat exchanger (22) is frozen, as in the first and second embodiments. Perform thawing operation to remove the frozen state.

In the above flow, the determination means (101C) according to the invention of claim 4 is controlled by step T6.
is configured.

Therefore, in the invention of claim 4, water, etc. Information related to the frozen state of the water is detected, and the determination means (101C) determines whether the water or the like is frozen based on this information. At that time, if you try to detect the frozen state of water, etc. with a normal temperature sensor, the detection part of the sensor will be exposed to the flow of water, etc., so the flow of water will be disturbed by the sensor, wiring, etc., and the supercooled state will disappear. Sometimes. Here, in the present invention, since information related to freezing of water, etc. is detected using a non-contact sensor, information related to the freezing state can be obtained without affecting the supercooled state of water, etc. , it is possible to improve detection accuracy.

[0083] In the third embodiment described above, freezing was determined when the light transmittance ε became equal to or less than the set value εs, but the present invention is not limited to such an embodiment, and the light transmittance Freezing may be determined based on the temporal change Δε of ε. Figure 11
shows a modification of the third embodiment, and in step Q1,
The data of the light transmittance ε is read, and in step Q2, the time change Δε of the light transmittance is calculated using the formula Δε=(ε−ε1)
/Δt (where ε1 is the data from the previous sampling and Δt is the sampling time), and in step Q3, it is determined whether Δε<Δεo (Δεo is a predetermined setting value) or not, and Δε Until <Δεo,
After updating the data in step Q4, step Q
5 returns to the main control routine. On the other hand, step Q3
If Δε<Δεo, then in step Q6,
It is determined that the water heat exchanger (22) is frozen, and a thawing operation is performed in step Q7. Also in this modification, the supercooled state of water etc. is not eliminated as in the third embodiment.
Freezing can be detected using a non-contact sensor to improve detection accuracy.

Furthermore, the non-contact sensor according to the fourth aspect of the invention is not limited to the light transmittance sensor (Ls) of the third embodiment. Although an example is omitted, for example, a detection unit such as an ultrasonic sensor, a mass flow meter, a conductivity meter, a capacitance sensor, etc. is attached to the outside of the piping of the water circulation path (51), and the ultrasonic waves detected by the ultrasonic sensor are Changes in velocity in liquid, changes in density of water, etc. detected by a mass flow meter, changes in conductivity of water, etc. detected by a conductivity meter, changes in capacitance detected by a capacitance sensor Freezing may also be detected from the following.

Next, the invention of claim 5 will be explained. In each of the above embodiments, in FIG. 3 the control is performed in step S8, in FIG. 4 the control is performed in step P9, in FIG. 7 the control is performed in step R10, and in FIG.
7, and in FIG. 11, the supercooling capacity of the water heat exchanger (22) is controlled by the control of step Q7 so as to eliminate the partially frozen state of water, etc. inside the water heat exchanger (22). A cooling capacity control means (102) is configured.

That is, in the invention of claim 5, in addition to the invention of claim 1, 2, 3 or 4, the determination means (101
), when it is determined that the water etc. inside the water heat exchanger (22) is partially frozen, for example, when hot gas is mixed into the water heat exchanger (22) in each of the above embodiments, , the cooling capacity control means (102) adjusts the supercooling capacity of water, etc. by the water heat exchanger (22) to be reduced, and the freezing is eliminated, so that the water heat exchanger (22) is completely frozen. Deterioration of ice making efficiency due to water heat exchanger (22)
damage can be effectively prevented.

Next, a fourth embodiment according to the sixth aspect of the invention will be described. FIG. 12 shows a piping system of an ice making apparatus according to a fourth embodiment, and the configuration is substantially the same as that of the piping system in the first embodiment, except for the connection between the preheating heat exchanger (6) and the refrigerant circuit (1). . However, the indoor unit (not shown) is not connected to the refrigerant circuit, and is cooled via a cooling medium such as water from the ice storage tank (5). In other words, only through the first pipe line (14) and the third pipe line (34), the refrigerant discharged from the compressors (11), (21) is condensed in the heat source side heat exchanger (12), and then the water side electric Expansion valve (2
3) constitutes a refrigerant circuit in which the refrigerant is circulated so as to be expanded and evaporated in the water heat exchanger (22). This supercools the water, etc. in the water circulation path (51).

[0088] Although two compressors are provided in this embodiment and each of the following embodiments, the configuration of the compressor is not limited to each embodiment.
The number of compressors may be one.

Here, the inlet side of the refrigerant flow section of the preheating heat exchanger (6) of the water circulation path (51) is connected to the preheating bypass path (61).
) is connected to the upstream and downstream liquid pipes of the heat source side electric expansion valve (13) of the refrigerant circuit, and the preheating on/off valve (63) is connected to the return pipe line (61b) of the preheating bypass line (61). )
is interposed therein, and a check valve (64) for preventing backflow of refrigerant is interposed in the outgoing pipe line (61a). Also, from the discharge line to the outgoing pipe line (61a) of the preheating bypass line (61)
A hot gas bypass passage (91) for bypassing the discharged refrigerant downstream of the check valve (64) is connected to the hot gas on-off valve (64).
92), and when the on-off valve (92) is opened, the discharged refrigerant is introduced into the preheating heat exchanger (6). The above preheating bypass path (61)
, the hot gas bypass path (91) and the hot gas on-off valve (92), the bypass means (
105) is configured.

[0090] Here, the configuration of the bypass means (105) is not limited to the above embodiment; for example, the gas side of the preheating heat exchanger (6) is directly connected to the discharge line, and the bypass means (105) is connected directly to the discharge line. The discharged refrigerant is also introduced into the preheating heat exchanger (6), while during thawing operation, the heat source side heat exchanger (12)
The heating capacity may be increased by increasing the refrigerant flow rate on the preheating heat exchanger (6) side by switching the gas side of the refrigerant to the suction line.

[0091] Note that the circuits related to the oil return pipes (RT1) and (RT2) of each compressor (11) and (21), and the circuits related to the thermal insulation heat exchanger (7) and recooler (8) are omitted. However, it is similar to the circuit shown in FIG. 2 of the first embodiment.

During normal ice-making operation, the hot gas on-off valve (92) of the hot gas bypass path (91) is closed;
The preheating on/off valve (63) of the preheating bypass passage (61) is opened, and the liquid refrigerant condensed in the heat source side heat exchanger (12) is transferred from the upstream side of the heat source side electric expansion valve (13) to the preheating heat exchanger (6). After being introduced into the water, the ice is returned to the downstream side of the electric expansion valve (13) on the heat source side, thereby preheating the water and the like supplied to the water heat exchanger (22) and melting the ice cores.

During ice making operation in the above ice making apparatus, the four-way switching valve (2) is switched to the solid line side in the figure, and the heat source side heat exchanger (1
2) The gas pipe is controlled to be connected to the discharge line. That is, the discharged refrigerant is condensed in the heat source side heat exchanger (12), the pressure is reduced in the water side electric expansion valve (23), and the water heat exchanger (
By evaporating the water in the water circulation path (51) and returning it to the compressors (11) and (21), the water is transferred to the water heat exchanger (22).
) to produce a slurry-like frozen product.

Also, during this ice-making operation, the water heat exchanger (2
2) is detected, the four-way selector valve (2) is detected to be frozen.
) to the side of the broken line in the figure and connect the gas pipe of the heat source side heat exchanger (12) to the suction line to function as an evaporator.
The water side electric expansion valve (23) is controlled to reduce the flow rate of refrigerant to the water heat exchanger (22), and the hot gas on/off valve (92) of the hot gas bypass path (91) is controlled to be opened. At this time, the cooling temperature of the water heat exchanger (22) is made to be higher than the freezing point of water, etc. by adjusting the opening of the water side electric expansion valve (23) and adjusting the capacity of the compressors (11) and (21). ing.

That is, the discharged refrigerant is preheated by the heat exchanger (6).
After being introduced into the compressor (11), the pressure is reduced by the heat source side electric expansion valve (13) and the water side electric expansion valve (23), and the heat source side heat exchanger (12) and water heat exchanger (22) evaporate the air. ), (2
By circulating it back to water heat exchanger (2)
2) while cooling the water etc. with the refrigerant flowing into the water heat exchanger (22), the water etc. heated to a high temperature in the preheating heat exchanger (6) upstream thereof flows into the water heat exchanger (22). Thaw the frozen. This control constitutes the thawing operation control means according to the invention of claim 6.

[0096] In winter, the water side electric expansion valve (26)
By switching to the dashed line side in the figure and making the water heat exchanger (22) function as a condenser, warm heat can be stored in the ice storage tank (5) and this warm water can be used to heat the room. is being done.

Therefore, in the invention of claim 6, during ice making operation, the operation is performed in a refrigeration cycle in which the refrigerant is circulated so that the heat source side heat exchanger (12) functions as a condenser and the water heat exchanger (22) functions as an evaporator. is carried out, and a slurry-like frozen product is produced in the water heat exchanger (22). On the other hand, when the freezing state of the water heat exchanger (22) is detected by the freezing detection means (for example, the temperature sensor, light transmittance sensor, ultrasonic sensor, etc. in the above-mentioned first to third embodiments) during the ice-making operation, The thawing operation control means controls the bypass means (105) to open the hot gas on-off valve (92) and increase the heating capacity of the preheating heat exchanger (6).

That is, while the water heat exchanger (22) cools the water, etc., the water heat exchanger (6) on the upstream side heats the water to a high temperature. )
Compared to the case where the water is heated directly, the temperature of the water at the outlet of the water heat exchanger (22) does not increase much, and it is possible to suppress heat loss and improve operational efficiency. At that time, on the refrigerant circuit side, the refrigeration cycle is switched so that the heat source side heat exchanger (12) functions as a condenser, so hot gas is introduced into the preheating heat exchanger (6) to increase heating capacity. This is offset by the evaporation capacity of the heat source-side heat exchanger (12), and heat transfer due to refrigerant circulation is performed smoothly.

Here, as in the invention of claim 9, the water side electric expansion valve (23) may be closed during the thawing operation, and at that time, the water heat exchanger (22) may be closed as well. Compared to direct thawing, the temperature near the tube wall does not rise as much, so when ice-making operation is resumed after thawing, the ice-making operation can be started more quickly. However, as shown by the broken line in Figure 21, the water side electric expansion valve (2
3), the water temperature at the outlet of the water heat exchanger (22) decreases only by a temperature drop corresponding to the thawing heat amount Q1 of the water heat exchanger (22). When cooling water, etc., a water heat exchanger (
A temperature drop corresponding to the endotherm Q2 in 22) is added. Therefore, by appropriately cooling the water heat exchanger (22) during the thawing operation, even though the input heat of the compressors (11) and (21) and the heat absorbed by all the evaporators Q3 are the same, the water heat exchanger (22) 22) It is possible to suppress the temperature rise of the water temperature Two at the outlet, and the heat loss is reduced accordingly.

[0100] Also, according to the invention of claim 10 or 11, when starting the thawing operation, the water side electric expansion valve (23) is closed;
If the water-side electric expansion valve (23) is opened when the water temperature Two at the outlet of the water heat exchanger (22) reaches a predetermined temperature or higher, or when a certain period of time has elapsed, the thawing operation time will be shortened. In addition to reducing heat loss,
It will be effective.

[0101] The thawing operation by the thawing operation control means can be determined to be stopped and the ice-making operation to be resumed when the conditions shown in Figs. 15 to 20 are satisfied. Here, (a) in FIG. 15 shows that the thawing operation is stopped when the flow rate f of water, etc. in the water circulation path (51) detected by the flow sensor returns to the value fo before freezing (time to in the figure). For example, (b) in FIG. 15 is an example in which the thawing operation is stopped when the time change df/dt of the flow rate f returns to the pre-freezing value "0" (time to in the figure). (a) in FIG. 16 shows when the differential pressure Δp between the water pressures p1 and p2 detected by two water pressure sensors installed on the upstream and downstream sides of the water heat exchanger (22) reaches the pre-freezing value Δpo. An example of stopping the defrosting operation at (time to in the figure), (b) in Fig. 16 shows water pressures p1 and p2.
The time change dΔp/dt of the differential pressure Δp of
'' (time to in the figure), the thawing operation is stopped. Figure 17 shows the outlet water temperature T detected by the temperature sensor installed in the recooler (8), which is the supercooling elimination section.
returns to the value before freezing (time to in the figure).
) is an example of stopping the defrosting operation. (a) of FIG. 18 is
Inlet water temperature T1 of water heat exchanger (22) and recooler (8)
The temperature difference ΔT from the outlet water temperature T2 is the value ΔTo before freezing.
(b) in FIG. 18 shows an example in which the thawing operation is stopped when the temperature difference ΔT reaches (time to in the figure) dΔT/
When dt reaches the value "0" before freezing (time to
) is an example of stopping the defrosting operation. (a) in FIG. 19 shows the time when the light transmittance ε detected by the light transmittance sensor installed on the exit side of the water heat exchanger (22) reaches the value εo before freezing (time to in the figure). An example of stopping the thawing operation at , (b) in FIG. 19 shows that the thawing operation is stopped when the time change in light transmittance dε/dt reaches the pre-freezing value "0" (time to in the figure). This is an example. FIG. 20(a) shows the state when the light transmittance ε′ detected by the light transmittance sensor installed on the exit side of the recooler (8) reaches the value ε′o before freezing ( An example of stopping the defrosting operation at time to ) is shown in FIG. 20 (
b) is an example in which the thawing operation is stopped when the time change dε'/dt of the light transmittance ε' reaches the pre-freezing value "0" (time to in the figure).

[0102] In particular, by determining whether the frozen state is resolved based on the detected value of the sensor as described above, it is possible to suppress heat loss caused by performing the thawing operation more than necessary.
Operational efficiency can be improved.

Next, a fifth embodiment according to the seventh aspect of the invention will be described. FIG. 13 shows a piping system of an air conditioner according to a fifth embodiment, and shows the configuration of the first embodiment except for the connection relationship between the refrigerant circuit (1) and the preheating heat exchanger (6) of the ice making device. 2) has almost the same configuration. And, between the refrigerant circuit (1) and the preheating heat exchanger (6), there is a preheating bypass passage (61) similar to the fourth embodiment (see FIG. 12), a preheating on/off valve (63), and a check valve. Valve (64), hot gas bypass path (91) and hot gas on/off valve (9
2) is provided. In addition, each compressor (11), (2
Although the oil return pipes (RT1) and (RT2) in 1) and the connecting piping between the heat insulating heat exchanger (7), recooler (8) and refrigerant circuit (1) are omitted, they are shown in Figure 2 above. It is the same as shown.

[0104] At night, etc., the hot gas on-off valve (
92) is closed and the four-way switching valve (2) is set to the solid line side in the figure, the refrigerant condensed in the outdoor heat exchanger (12) is evaporated in the water heat exchanger (22) to make ice. , a part of the liquid refrigerant on the downstream side of the outdoor heat exchanger (12) is transferred to the preheating heat exchanger (6).
) side to melt ice nuclei such as water that is supplied to the water heat exchanger (22). In addition, the water heat exchanger (22) becomes frozen during ice-making operation, and the freeze detection means (temperature sensor, ultrasonic sensor, etc. as in each of the above embodiments)
When freezing of the water heat exchanger (22) is detected by The outdoor motorized expansion valve (13) is closed by switching to the solid line side in the figure, and after condensing the discharged refrigerant in the preheating heat exchanger (6), each indoor heat exchanger (32), (32) and water heat exchanger By evaporating it in (22) and returning it to the compressors (11) and (21),
The water and the like are cooled by the water heat exchanger (22) while the water and the like are heated by the preheating heat exchanger (6) to thaw out the freezing of the water heat exchanger (22). This control constitutes the thawing operation control means according to the seventh aspect of the invention. Note that when the thawing operation is to be stopped, the determination is made using the method shown in FIGS. 15 to 20 above.

Therefore, in the invention of claim 7, during ice making operation, the refrigerant is circulated so that the outdoor heat exchanger (12) functions as a condenser and the water heat exchanger (22) functions as an evaporator. By supercooling the water, etc. in the water circulation path (51) with the heat exchanger (22), a slurry-like frozen product is generated. At that time, the water heat exchanger (22
) is detected, the thawing operation control means opens the hot gas on-off valve (92) while adjusting the opening degree of the water-side electric expansion valve (23), and also opens the hot gas on-off valve (92). ), (32) and the water heat exchanger (22) serve as evaporators, the water circulation path (51) is configured to operate the water heat exchanger (22) as an evaporator. By heating water or the like in the preheating heat exchanger (6) while performing cooling with a refrigerant in the exchanger (22), the water heat exchanger (22) is thawed while reducing heat loss.

[0106] On the refrigerant circuit (1) side, the indoor heat exchangers (32) and (32) function as evaporators, making it possible to directly cool the room using the refrigerant.

[0107] In the fifth embodiment, as in the fourth embodiment, the ice storage tank (5) is It is also possible to store heat in the

Next, a sixth embodiment according to the eighth aspect of the invention will be described. FIG. 14 shows a piping system of an air conditioner according to a sixth embodiment. In addition to the configuration of the fifth embodiment (see FIG. 13), the gas side piping of each indoor heat exchanger (32), An indoor four-way switching valve (36) that is an indoor switching mechanism for selectively communicating the air with the discharge line and the suction line.
is provided, and the four-way switching valve (2) is an outdoor switching mechanism according to the invention of claim 8. In addition, (C5), (C6
) are respectively four-way switching valve (2) and indoor four-way switching valve (36).
This is a capillary tube installed on the dead port side of the

[0109] At night, etc., each four-way switching valve (2)
, (26), and (36) are set to the solid line side in the figure, the hot gas on-off valve (92) is closed, and each compressor (11), (
The refrigerant discharged from 21) is transferred to each indoor heat exchanger (32), (3
2) and after being condensed in the outdoor heat exchanger (12), the pressure is reduced by the water side electric expansion valve (23), and the water is evaporated in the water heat exchanger (22). (51
) is supercooled to produce a slurry-like frozen product.

[0110] When the water heat exchanger (22) freezes during ice-making operation, the hot gas on-off valve (92) is opened while adjusting the opening degree of the water-side electric expansion valve (23), and the four-way Both the switching valve (2) and the indoor four-way switching valve (36) are switched to the broken line side in the figure, and the compressors (11), (21)
The refrigerant discharged from the is condensed in the preheating heat exchanger (6) and reduced in pressure by each electric expansion valve (13), (33), (33), and then transferred to the outdoor heat exchanger (12) and each indoor heat exchanger. (32), (
32) and the water heat exchanger (22), and the compressor (1
1) and (21), the water, etc. is heated in the preheating heat exchanger (6) on the upstream side of the water heat exchanger (22), and the water, etc., is heated and frozen in the water heat exchanger (22). I'm trying to melt it. This control constitutes the thawing operation control means according to the eighth aspect of the invention.

Therefore, in the invention of claim 8, during the ice-making operation, each of the four-way switching valves ( 2) and (36) are controlled, and the refrigerant discharged from the compressors (11) and (21) is condensed in the outdoor heat exchanger (12) and each indoor heat exchanger (32) and (32), Circulate to evaporate in the water heat exchanger (22),
Water, etc. in the water circulation path (51) is supercooled in the water heat exchanger (22), and ice is made. At that time, when the freezing state of the water heat exchanger (22) is detected by the freezing detection means, the thawing operation control means opens the hot gas on-off valve (92), and the outdoor heat exchanger (12) and each indoor Heat exchanger (32
), (32) and the water heat exchanger (22) are all evaporators.
) is controlled, and the switching of the preheating heat exchanger (6) is controlled.
Since the bypass means (105) is controlled to increase the heating capacity of the water circulation path (51),
The water heat exchanger (22) is thawed while reducing heat loss by the same action as in the invention of the above.

On the other hand, on the refrigerant circuit (1) side, the compressor (1
The refrigerant discharged from 1), (21) is condensed in the preheating heat exchanger (6), and the refrigerant is transferred to each heat exchanger (12), (32), (32),
(22) to evaporate, so the outdoor heat exchanger (
12) and indoor heat exchangers (32), (32) can be used as evaporators. Therefore, compared to the invention of claim 7, the condensing capacity of the preheating heat exchanger (6) can be improved, and therefore, significant effects can be exhibited.

[0113] Similarly to the above embodiments, in winter, etc., the four-way switching valve (2) is switched to the broken line side in the figure and the indoor four-way switching valve (36) is switched to the solid line side in the figure to perform heating operation. At the same time, by switching the water side four-way switching valve (26) to the side shown by the broken line in the figure, it is possible to store warm heat in the ice storage tank (5) at night. In particular, when the outdoor heat exchanger (13) is frosted during heating operation, the four-way switching valve (2) is switched to the solid line side in the figure, and the water side four-way switching valve (26) is switched to the solid line side in the figure. The water side electric expansion valve (23) is opened, and the outdoor heat exchanger (13) and each indoor heat exchanger (32), (32) are used as a condenser, and the water heat exchanger (22) is used as an evaporator. It is possible to carry out a forward cycle defrost operation to melt frost on the outdoor heat exchanger (13) while heating the outdoor heat exchanger (13).

[0114]

As explained above, according to the invention of claim 1, in an ice making apparatus in which water or an aqueous solution in an ice storage tank is circulated through a water circulation path and supercooled by a water heat exchanger,
The temperature of the water, etc. at the outlet of the water heat exchanger is detected, and when the increase in the outlet water temperature exceeds a predetermined value, it is determined that the water, etc. inside the water heat exchanger is partially frozen. As a result, partial freezing inside the water heat exchanger can be accurately detected from the rise in outlet water temperature due to the generation of solidification heat.
Therefore, it is possible to take effective preventive measures against complete freezing of the water heat exchanger.

According to the invention of claim 2, in the ice making apparatus in which the water heat exchanger supercools water etc. by heat exchange with the refrigerant of the refrigerant circuit of the refrigeration system, the outlet water temperature of the water heat exchanger and When the increase in the difference between the evaporation temperature of the refrigerant in the water heat exchanger and the evaporation temperature of the refrigerant exceeds a predetermined value, it is determined that the water in the water heat exchanger is partially frozen. Partial freezing inside the exchanger can be detected more accurately.

According to the invention of claim 3, in the invention of claim 1 or 2, the partial reduction of water, etc. in the water heat exchanger is also taken into account the change in the flow rate of water, etc. in the water heat exchanger. Since the frozen state is determined, it becomes possible to detect partial freezing more accurately.

According to the invention of claim 4, in the ice making apparatus similar to the invention of claim 1 or 2, information related to freezing of water, etc. at the outlet of the water heat exchanger is detected by a non-contact sensor, Based on the amount of information detected by the contact sensor, it is determined that the water or aqueous solution inside the water heat exchanger is partially frozen, so it can be frozen with high accuracy without eliminating the supercooled state of water, etc. The state can be detected.

According to the invention of claim 5, the above-mentioned claim 1,
In addition to inventions 2, 3, and 4, when partial freezing occurs in the water heat exchanger, the supercooling capacity of the water heat exchanger is controlled so as to eliminate the frozen state. Full-scale freezing can be effectively prevented.

According to the invention of claim 6, a preheating heat exchanger for preheating water, etc. is provided upstream of the water heat exchanger in the water circulation path of the ice making apparatus, and a compressor, a heat source side heat exchanger, and a heat source side decompression A refrigerant circuit is formed by sequentially connecting a valve, a pressure reducing valve for ice making, and a water heat exchanger, a switching mechanism that switches the heat source side heat exchanger to a condenser and an evaporator, and a refrigerant circuit that connects the refrigerant circuit to the preheating heat exchanger. If the water heat exchanger freezes during ice-making operation, the heat exchanger on the heat source side is switched to the evaporator, the heating capacity of the preheating heat exchanger is increased, and the water heat exchanger is Since the water is cooled by the upstream preheating heat exchanger while being heated by the upstream preheating heat exchanger, it is possible to quickly unfreeze the water heat exchanger while suppressing the rise in water temperature at the outlet of the water heat exchanger. Therefore, it is possible to improve operational efficiency.

According to the invention of claim 7, a preheating heat exchanger for preheating water, etc. is provided upstream of the water heat exchanger in the water circulation path of the ice making apparatus, and a compressor, an outdoor heat exchanger, an outdoor pressure reducing valve, A refrigerant circuit is formed by sequentially connecting an indoor pressure reducing valve and an indoor heat exchanger, while a switching mechanism for switching the refrigeration cycle of the refrigerant circuit and a water heat exchanger are connected to the liquid pipes and the water heat exchanger of the refrigerant circuit via an ice making pressure reducing valve. An ice-making bypass line connected to the suction line and a bypass means for bypassing the refrigerant from the refrigerant circuit are provided in the preheating heat exchanger, so that when the water heat exchanger freezes during ice-making operation, the indoor heat exchanger is connected to the evaporator. Since the refrigeration cycle is switched to increase the heating capacity of the preheating heat exchanger, it is possible to improve the operating efficiency similarly to the invention of claim 6, and also to directly utilize the refrigerant circuit. It is possible to cool the room.

According to the invention of claim 8, a preheating heat exchanger for preheating water, etc. is provided upstream of the water heat exchanger in the water circulation path of the ice making apparatus, and a compressor, an outdoor heat exchanger, an outdoor pressure reducing valve, two switching mechanisms that sequentially connect an indoor pressure reducing valve and an indoor heat exchanger to form a refrigerant circuit, while individually switching the outdoor heat exchanger and the indoor heat exchanger to a condenser and an evaporator;
A switching mechanism that switches the refrigeration cycle of the refrigerant circuit, an ice-making bypass path that connects the water heat exchanger to the liquid pipe and suction line of the refrigerant circuit via an ice-making pressure reducing valve, and a bypass passage for refrigerant from the refrigerant circuit to the preheating heat exchanger. If the water heat exchanger freezes during ice-making operation, the refrigeration cycle is switched so that the outdoor heat exchanger and indoor heat exchanger become evaporators, and the heating capacity of the preheating heat exchanger is reduced. Since it is made to increase, it is possible to improve the operating efficiency similarly to the invention of claim 7, and also to improve the heating capacity of the water heat exchanger during thawing operation.

According to the invention of claim 9, the above-mentioned claim 6,
In the invention of 7 or 8, the pressure reducing valve for ice making is closed during the thawing operation, so the temperature near the pipe wall does not rise as much as compared to the case where the water heat exchanger is used as a condenser for direct thawing. Another advantage is that when returning to ice-making operation after thawing, the start-up to ice-making is faster.

According to the invention of claim 10 or 11, in the invention of claim 6, 7 or 8, the pressure reducing valve for ice making is closed at the start of the thawing operation, and the water temperature at the outlet of the water heat exchanger reaches a predetermined temperature or higher. or when a certain period of time has passed,
Since the pressure reducing valve for ice making is opened, the time for the thawing operation can be shortened, and heat loss can be reduced, so that significant effects can be exhibited.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of the invention according to claims 1, 2, 3, and 5.

FIG. 2 is a piping system diagram of the air conditioner according to the first embodiment.

FIG. 3 is a flowchart showing control details according to the invention of claim 1 in the first embodiment.

FIG. 4 is a flowchart showing control contents according to the invention of claim 2 in the first embodiment.

FIG. 5 is a characteristic diagram showing temporal changes in the outlet water temperature of the water heat exchanger, the evaporation temperature of the refrigerant, and the flow rate of water, etc. in the first embodiment.

FIG. 6 is a piping system diagram of an air conditioner according to a second embodiment.

FIG. 7 is a flowchart showing control details in a second embodiment.

FIG. 8 is a cross-sectional view showing a structure near a non-contact sensor mounting portion according to a third embodiment.

FIG. 9 is a characteristic diagram showing the time-varying characteristics of light transmittance in the third example.

FIG. 10 is a flowchart showing the details of freeze detection control based on a decrease in light transmittance in the third embodiment.

FIG. 11 is a modification of the third embodiment, and is a flowchart showing the contents of freeze detection control based on temporal changes in light transmittance.

FIG. 12 is a piping system diagram of an ice making apparatus according to a fourth embodiment.

FIG. 13 is a piping system diagram of an air conditioner according to a fifth embodiment.

FIG. 14 is a piping system diagram of an air conditioner according to a sixth embodiment.

FIG. 15 is a diagram showing a method of detecting the end of freezing using a flow rate sensor.

FIG. 16 is a diagram illustrating a method of detecting the end of freezing using pressure sensors at two locations on the upstream and downstream sides of a water heat exchanger.

FIG. 17 is a diagram showing a method of detecting the end of freezing using a temperature sensor on the downstream side of the recooler.

FIG. 18 is a diagram showing a method of detecting the end of freezing using temperature sensors on the upstream side of the water heat exchanger and the downstream side of the recooler.

FIG. 19 is a diagram showing a method of detecting the end of freezing using a light transmittance sensor on the downstream side of the water heat exchanger.

FIG. 20 is a diagram showing a method of detecting the end of freezing using a light transmittance sensor on the downstream side of the recooler.

FIG. 21 is a diagram for comparing changes in water temperature at the outlet of the water heat exchanger when the water-side electric expansion valve is opened and closed during thawing operation.

[Explanation of symbols]

1 Refrigerant circuit 2 Four-way switching valve (outdoor switching mechanism) 5 Ice storage tank 6 Preheating heat exchanger 11, 21 Compressor 12 Outdoor heat exchanger (heat source side heat exchanger) 13 Outdoor electric expansion valve (outdoor pressure reducing valve, heat source side heat exchanger) side pressure reducing valve) 22 Water heat exchanger 23 Water side electric expansion valve (ice making pressure reducing valve) 28 Ice making bypass path 32 Indoor heat exchanger 33 Indoor electric expansion valve (indoor pressure reducing valve) 36 Indoor four-way switching valve (indoor switching mechanism ) 51 Water circulation path 61 Preheating bypass path 91 Hot gas bypass path 92 Hot gas on/off valve 101 Judgment means 102 Capacity control means 105 Bypass means Thw Temperature sensor (water temperature detection means) Pe Pressure sensor (evaporation temperature detection means) Fm Flow meter (flow rate detection means)

Claims (11)

[Claims] Claim 1: An ice storage tank (5) for storing frozen material in the form of a slurry of water or an aqueous solution, connected to a cooling device,
A water heat exchanger (22) for supercooling water or an aqueous solution, and a water circulation path (for forced circulation of water or an aqueous solution between the water heat exchanger (22) and the ice storage tank (5)). 51) and water temperature detection means (Thw) for detecting the temperature of the water or aqueous solution at the outlet of the water heat exchanger (22)
), and in response to the output of the water temperature detection means (Thw), when the increase in the outlet temperature of the water or aqueous liquid is larger than a predetermined value, the water or aqueous solution inside the water heat exchanger (22) partially An ice-making device characterized by comprising a determining means (101A) for determining that the ice-making device is frozen. Claim 2: An ice storage tank (5) for storing a slurry-like frozen product of water or an aqueous solution, and a refrigerant circuit (5) of a refrigeration system.
1) for supercooling the water or aqueous solution, and forced circulation of water or the aqueous solution between the water heat exchanger (22) and the ice storage tank (5). The water heat exchanger (
22) A water temperature detection means (Thw) for detecting the temperature of water or aqueous solution at the outlet, and a water heat exchanger (Thw) of the refrigerant circuit (1).
22) An evaporation temperature detection means (Pe) that detects the evaporation temperature of the refrigerant at the outlet, receives the outputs of the water temperature detection means (Thw) and the evaporation temperature detection means (Pe), and detects the outlet temperature of water or aqueous solution and the evaporation of the refrigerant. determining means (10) for determining that the water or aqueous solution inside the water heat exchanger (22) is partially frozen when the increase in the difference from the temperature is larger than a predetermined value;
1B). 3. The ice making apparatus according to claim 1, further comprising a flow rate detection means (Fm) for detecting the flow rate of water or aqueous solution flowing into the water heat exchanger (22), and a determination means (10).
1A or 101B) is characterized in that it is determined that the water or aqueous solution inside the water heat exchanger (22) is partially frozen by taking into account a decrease in the flow rate of the water or aqueous solution. Ice making equipment. 4. An ice storage tank (5) for storing frozen material in the form of a slurry of water or an aqueous solution, connected to a cooling device,
A water heat exchanger (22) for supercooling water or an aqueous solution, and a water circulation path (for forced circulation of water or an aqueous solution between the water heat exchanger (22) and the ice storage tank (5)). 51) and a non-contact sensor that detects information related to freezing of water or aqueous solution at the outlet of the water heat exchanger (22) without contacting the water or aqueous solution, and information detected by the non-contact sensor. An ice-making apparatus comprising: determination means (101C) for determining whether water or aqueous solution inside the water heat exchanger (22) is partially frozen based on the amount of water or aqueous solution inside the water heat exchanger (22). 5. The ice making apparatus according to claim 1, 2, 3, or 4, wherein the partially frozen state of the water or aqueous solution inside the water heat exchanger (22) is released in response to the output of the determining means (101). 4. The ice making apparatus according to claim 1, further comprising a cooling capacity control means (102) for controlling the supercooling capacity of the water heat exchanger (22) so as to achieve the following. 6. An ice storage tank (5) for storing a slurry-like frozen product of water or an aqueous solution, a water heat exchanger (22) for supercooling the water or an aqueous solution, and the water heat exchanger (22) for supercooling the water or the aqueous solution. Vessel (22
) and the ice storage tank (5), a water circulation path (51) for forced circulation of water or an aqueous solution, and the water circulation path (51).
The water heat exchanger (22) is arranged upstream of the water heat exchanger (22).
22), a preheating heat exchanger (6) for preheating the water or aqueous solution supplied to the compressor (11), (21), a heat source side heat exchanger (12), a heat source side pressure reducing valve (13), A refrigerant circuit is formed by sequentially connecting an ice-making pressure reducing valve (23) and the water heat exchanger (22), and a gas pipe of the heat source side heat exchanger (12) is selectively used as a discharge line or a suction line. It is equipped with a switching mechanism (2) for switching to communicate with the water, and a bypass means (105) for introducing a heating refrigerant such as water or an aqueous solution from the refrigerant circuit into the refrigerant flow section of the preheating heat exchanger (6). A freeze detection means for detecting a frozen state of water or aqueous solution inside the water heat exchanger (22) during ice making operation in the heat exchanger (22), and receiving an output of the freeze detection means;
When the inside of the water heat exchanger (22) freezes, the switching mechanism (2) is switched to connect the gas pipe of the heat source side heat exchanger (12) to the suction line, and the preheating heat exchanger (6) An ice-making apparatus comprising: a thawing operation control means for controlling the bypass means (105) to increase the heating capacity of the ice-making apparatus. 7. An ice storage tank (5) for storing a slurry-like frozen product of water or an aqueous solution, a water heat exchanger (22) for supercooling the water or an aqueous solution, and the water heat exchanger (22) for supercooling the water or the aqueous solution. Vessel (22
) and the ice storage tank (5), a water circulation path (51) for forced circulation of water or an aqueous solution, and the water circulation path (51).
The water heat exchanger (22) is arranged upstream of the water heat exchanger (22).
22), a preheating heat exchanger (6) that preheats the water or aqueous solution supplied to the compressors (11), (21), an outdoor heat exchanger (12), an outdoor pressure reducing valve (13), and an indoor pressure reducing Valve (3
3) and an indoor heat exchanger (32) connected in sequence; a switching mechanism (2) for switching the refrigeration cycle of the refrigerant circuit (1) between forward and reverse; and the water heat exchanger (22). ) is connected to the outdoor pressure reducing valve (13) of the refrigerant circuit (1) - the indoor pressure reducing valve (33) via the ice making pressure reducing valve (23).
), an ice-making bypass path (24) connecting the outlet side to the suction line, and a refrigerant flow section of the preheating heat exchanger (6) for heating water or aqueous solution from the refrigerant circuit (1). a bypass means (105) for introducing a refrigerant, and a freeze detection means for detecting a frozen state of water or an aqueous solution inside the water heat exchanger (22) during ice making operation in the water heat exchanger (22); , upon receiving the output of the freeze detection means, a switching mechanism (
2) and thawing operation control means for controlling the bypass means (105) to increase the heating capacity of the preheating heat exchanger (6). 8. An ice storage tank (5) for storing a slurry-like frozen product of water or an aqueous solution, a water heat exchanger (22) for supercooling the water or an aqueous solution, and the water heat exchanger (22) for supercooling the water or the aqueous solution. Vessel (22
) and the ice storage tank (5), a water circulation path (51) for forced circulation of water or an aqueous solution, and the water circulation path (51).
The water heat exchanger (22) is arranged upstream of the water heat exchanger (22).
22), and a preheating heat exchanger (6) for preheating the water or aqueous solution supplied to the compressor (11), (21).
), an indoor heat exchanger (12), an outdoor pressure reducing valve (13), an indoor pressure reducing valve (33), and an indoor heat exchanger (32) are sequentially connected to each other. 12) and an outdoor switching mechanism (2) and an indoor switching mechanism (36) that switch the gas pipes of the indoor heat exchanger (32) to selectively communicate with the discharge line and the suction line, respectively, and the water heat exchanger (22) to the liquid pipe between the outdoor pressure reducing valve (13) and the indoor pressure reducing valve (33) of the refrigerant circuit (1) via the ice making pressure reducing valve (23) having an opening/closing function on the inlet side of the refrigerant flow section; An ice-making bypass line that connects the outlet side to the suction line (
24) and a bypass means (105) for introducing a heating refrigerant such as water or an aqueous solution from the refrigerant circuit (1) into the refrigerant flow section of the preheating heat exchanger (6), and During the ice making operation in step 22), a freeze detection means detects the frozen state of the water or aqueous solution inside the water heat exchanger (22), and upon receiving the output of the freeze detection means, the inside of the water heat exchanger (22) freezes. When the above outdoor heat exchanger (
12) and the indoor heat exchanger (32) to communicate with the suction line, and at the same time, the switching mechanisms (2) and (36) are switched so that the gas pipes of the indoor heat exchanger (32) and the indoor heat exchanger (32) are switched, and the heating capacity of the preheating heat exchanger (6) is increased. An ice making apparatus comprising: a thawing operation control means for controlling a bypass means (105). 9. In the ice making apparatus according to claim 6, 7 or 8, the ice making pressure reducing valve (23) has a flow rate adjustment function, and the thawing operation control means controls the ice making pressure reducing valve (23) during the thawing operation. ) is controlled to close. 10. The ice making apparatus according to claim 6, 7 or 8, further comprising a water temperature detection means (Thw) for detecting the temperature of the water or aqueous solution at the outlet of the water heat exchanger (22), and an ice making pressure reducing valve (23). ) has a flow rate adjustment function, and the thawing operation control means receives the output of the water temperature detection means (Thw), closes the ice making pressure reducing valve (23) at the start of the thawing operation, and then closes the water heat exchanger (Thw). 22) An ice-making apparatus characterized in that the ice-making pressure reducing valve (23) is controlled to open when the temperature of the water or aqueous solution at the outlet reaches a predetermined value or higher. 11. The ice making apparatus according to claim 6, 7 or 8, further comprising a timer for measuring the elapsed time after the thawing operation is started by the thawing operation control means, and the ice making pressure reducing valve (23) is configured to control the flow rate. The thawing operation control means receives the output of the timing means, and after closing the ice making pressure reducing valve (23) at the start of the thawing operation, the thawing operation control means determines whether the elapsed time after the start of the thawing operation exceeds a certain period of time. Then, the pressure reducing valve for ice making (
23) An ice making device that is controlled to open.