JP2009079788A - Refrigerating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating device capable of saving energy while reducing device costs and saving a space. <P>SOLUTION: In this refrigerating device, a part of a refrigerant discharged from a first condenser 14 is evaporated in an evaporation-side passage 66a of a heat exchanger through a third expander 64 disposed at an inflow port side of the heat exchanger 66, and the refrigerant discharged from a second compressor 32 is condensed in a condensation-side passage 66b of the heat exchanger, and the heat exchanger condenses the refrigerant circulated in the condensation-side passage by utilizing the water. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus, and more particularly to a refrigeration apparatus suitable for use in refrigeration and freezing showcases installed in stores such as convenience stores.

  This type of refrigeration apparatus is configured to be capable of cooling a refrigeration and freezing showcase installed in a store such as a convenience store, and includes a refrigerated compressor, condenser, expander, and evaporator. A refrigeration side refrigerant circuit, a refrigeration side refrigerant circuit of a refrigeration showcase comprising a compressor, an expander and an evaporator on the refrigeration side, and a cascade capacitor for exchanging heat between the refrigeration side refrigerant circuit and the refrigeration side refrigerant circuit (For example, refer to Patent Document 1).

In addition, a new condenser is installed in the refrigeration side refrigerant circuit, and depending on the heat load of the refrigeration side refrigerant circuit, only the refrigeration side condenser is used, or both the refrigeration side condenser and the cascade condenser are used. It is selected whether to use, and the refrigeration side refrigerant circuit and the refrigeration side refrigerant circuit can be operated independently without increasing the cooling capacity of the refrigeration side refrigerant circuit. A technique capable of promoting the conversion is known (see, for example, Patent Document 2).
JP 2001-91073 A JP 2005-257164 A

However, in Patent Document 2, since a refrigeration side condenser is required in addition to the cascade condenser, the equipment cost of the refrigeration side refrigerant circuit and thus the refrigeration apparatus is increased, and it is necessary to secure a large installation space. There are still issues to be addressed.
This invention is made | formed in view of such a subject, and it aims at providing the freezing apparatus which can implement | achieve energy saving, aiming at reduction of apparatus cost and space saving.

  In order to achieve the above object, a refrigeration apparatus according to claim 1 includes a first refrigerant circuit including a first compressor, a first condenser, a first expander, and a first evaporator; Heat exchange for exchanging heat between the refrigerant in the first refrigerant circuit and the refrigerant in the second refrigerant circuit, and a second refrigerant circuit composed of the second compressor, the second expander, and the second evaporator. A part of the refrigerant discharged from the first condenser is evaporated in the evaporation side path of the heat exchanger via a third expander provided on the inlet side of the heat exchanger. The refrigeration apparatus condenses the refrigerant discharged from the second compressor in the condensation side path of the heat exchanger, and the heat exchanger condenses the refrigerant flowing through the condensation side path using water. It is characterized by.

The invention according to claim 2 is characterized in that, in claim 1, the heat exchanger includes a case in which the evaporation side path and the condensation side path are accommodated and water is stored.
Further, the invention according to claim 3 is characterized in that, in claim 2, the case has a water supply port to which water is supplied and a drain port from which water is discharged.
Furthermore, the invention according to claim 4 is characterized in that, in claim 2 or 3, the heat exchanger is configured such that water flowing in the case forms a counter flow with the refrigerant flowing in the condensing channel. It is said.

The invention according to claim 5 is characterized in that, in claim 3 or 4, the water supply port is formed in the lower part of the case and the drainage port is formed in the upper part of the case.
Furthermore, in the invention described in claim 6, in any one of claims 2 to 5, the heat exchanger has a stirring means for stirring water in the case.
Furthermore, in the invention according to claim 7, in any one of claims 1 to 6, the heat exchanger is configured such that the refrigerant flowing through the evaporation side path and the refrigerant flowing through the condensation side flow path are opposed to each other. It is characterized by being.

The invention according to claim 8 is characterized in that in any one of claims 1 to 7, the heat exchanger is arranged such that the evaporation side path and the condensation side path are in contact with each other.
Further, according to a ninth aspect of the present invention, in the heat exchanger according to any one of the first to eighth aspects, the evaporating side path and the condensing side path are formed in a substantially elliptical shape in cross section, and these elliptical flat surfaces Are arranged opposite to each other.

Furthermore, the invention according to claim 10 is the control according to any one of claims 1 to 9, wherein the first on-off valve for opening and closing the inflow port of the evaporation side passage and the first on-off valve are electrically connected. The control unit is characterized in that the first on-off valve is closed during the defrosting operation of the first refrigerant circuit.
According to an eleventh aspect of the present invention, in the second or third aspect, the case includes a first case in which the condensation side path is accommodated and a second case in which the evaporation side path is accommodated. The first case and the second case are characterized in that they communicate with each other through a circulation path provided with a pump.

Further, the invention according to claim 12 is characterized in that, in claim 10, the control section closes the first on-off valve when the thermal load of the first refrigerant circuit becomes a predetermined value or more.
Furthermore, the invention of claim 13 further includes a water temperature sensor for detecting the temperature of the water in the case and a second opening / closing valve for opening / closing the water supply port or the drain port. The second on-off valve is opened when the temperature of the water detected by the temperature sensor is equal to or higher than the temperature of the water flowing through the water supply port.

  According to the refrigeration apparatus of the first aspect of the present invention, the heat exchanger that exchanges heat between the refrigerants of the first and second refrigerant circuits condenses after being discharged from the second compressor using water. The refrigerant flowing through the side path is condensed. Accordingly, since the first refrigerant circuit and the second refrigerant circuit can be operated independently without separately installing a condenser in the second refrigerant circuit, the second refrigerant circuit and thus the refrigeration Energy saving of the refrigeration apparatus can be realized while reducing the equipment cost and space saving of the apparatus.

  According to invention of Claim 2, the heat exchanger is provided with the case where water is stored while the evaporation side channel | path and the condensation side channel | path are accommodated. As a result, water can be brought into contact with the evaporation side path to store the excess cooling capacity of the first refrigerant circuit in the water, and the condensation side path can be circulated as compared with a general air-cooled condenser. Since the cooling efficiency of the refrigerant to be improved can be improved, it is possible to further promote energy saving of the refrigeration apparatus.

In addition, since the cooling efficiency in the condensation side path is improved, the amount of heat exchange per unit heat transfer area in the heat exchanger is increased, so that the condensation side path and thus the heat exchanger can be relatively downsized. As a result, space saving of the refrigeration apparatus can be further promoted.
According to the invention described in claim 3, the case has a water supply port to which water is supplied and a drain port from which water is discharged. Therefore, even if the refrigeration apparatus is stopped by maintenance and the temperature of the water stored in the case rises, it can be operated while ensuring the cooling capacity of the second refrigerant circuit by running water. Reliability can be improved.

According to invention of Claim 4, a heat exchanger is comprised so that the water which distribute | circulates the inside of a case may make a counter flow with the refrigerant | coolant which distribute | circulates a condensation side flow path. Thereby, the heat exchange efficiency with the water which distribute | circulates the inside of a case, and the refrigerant | coolant which distribute | circulates a condensing side flow path improves, and can further promote energy saving of a freezing apparatus.
According to the invention of claim 5, since the water supply port is formed in the lower part of the case and the drain port is formed in the upper part of the case, it is possible to reliably prevent the occurrence of air accumulation in the case. The heat exchange efficiency between the water flowing through the case and the refrigerant flowing through the evaporation side path, and thus the refrigerant flowing through the condensation side path, can be improved, and energy saving of the refrigeration apparatus can be further promoted.

According to the sixth aspect of the present invention, the heat exchanger has the stirring means for stirring the water in the case, so that the cold heat of the water stored by the refrigerant flowing through the evaporation side passage is spread throughout the case. be able to. Therefore, it is possible to improve the heat exchange efficiency between the water in the case and the refrigerant flowing through the evaporation side path, and hence the condensation side path, and further promote energy saving of the refrigeration apparatus.
In addition, since the amount of heat exchange per unit heat transfer area in the heat exchanger increases, the capacity of the case can be relatively reduced, and further space saving of the refrigeration apparatus can be further promoted.

According to the seventh aspect of the present invention, the heat exchanger is configured so that the refrigerant flowing through the evaporation side path and the refrigerant flowing through the condensation side flow path are opposed to each other, whereby the evaporation side path and the condensation side are configured. The heat exchange efficiency between the refrigerants flowing through the flow path is improved, and energy saving of the refrigeration apparatus can be further promoted.
According to the invention of claim 8, the heat exchanger is arranged such that the evaporation side path and the condensation side path are in contact with each other, whereby the heat exchange efficiency between the refrigerants flowing through the evaporation side path and the condensation side path. The energy saving of the refrigeration apparatus can be further promoted.

  According to the ninth aspect of the present invention, the heat exchanger is configured such that the evaporation side passage and the condensation side passage are formed in a substantially elliptical shape in cross section, and these elliptical flat surfaces are arranged to face each other. Since the heat transfer area of the evaporation side path and the condensation side path can be increased, the efficiency of heat exchange between the refrigerant flowing through the evaporation side path and the condensation side path and between the refrigerant and the water in the case is improved. Thus, energy saving of the refrigeration apparatus can be further promoted.

  According to the invention of claim 10, the control unit closes the first on-off valve that opens and closes the inlet of the evaporation side path during the defrosting operation of the first refrigerant circuit. Thereby, since the refrigerant does not flow through the evaporation side path, the refrigerant flowing through the condensation side path is condensed only by water in the case, and the operation of the first refrigerant circuit can be stopped. Therefore, the power loss of operating the first refrigerant circuit only for the purpose of operating the second refrigerant circuit during the defrosting operation of the first refrigerant circuit is eliminated, and further energy saving of the refrigeration apparatus is further promoted. be able to.

  According to the eleventh aspect of the present invention, the case includes a first case in which the condensing side path is accommodated and a second case in which the evaporation side path is accommodated, and the first case and the second case. The case communicates with a circulation path including a pump. This also makes it possible to easily store the excess cooling capacity of the first refrigerant circuit in the water, and to cool the water in the water, and to circulate the flowing water in the circulation path by the pump and to operate while ensuring the cooling capacity of the second refrigerant circuit. The reliability of the refrigeration apparatus can be improved while promoting energy saving.

  According to the twelfth aspect of the present invention, the control unit closes the first on-off valve when the thermal load of the first refrigerant circuit is equal to or greater than a predetermined value. Thereby, especially at the peak heat load of the first refrigerant circuit, such as during the daytime in summer, since the refrigerant does not flow through the evaporation side path, heat exchange between the refrigerants flowing through the evaporation side path and the condensation side path is blocked, The cooling capacity of the first refrigerant circuit can be reliably ensured, and the reliability of the refrigeration apparatus can be improved.

  According to the invention of claim 13, the control unit opens and closes the water supply port or the drain port when the temperature of the water detected by the water temperature sensor is equal to or higher than the water supply temperature of the water flowing through the water supply port. Open the on-off valve. As a result, even if all of the cold heat of the stored water is used to condense the refrigerant flowing through the condensation side path, the water in the case is automatically lowered to a temperature lower than the feed water temperature by circulating the water in the case. Even if the first refrigerant circuit is stopped for a long time exceeding the cold storage capacity of water due to a failure or maintenance of the refrigeration system, the second refrigerant circuit is operated independently while ensuring the cooling capacity. This can further improve the reliability of the refrigeration apparatus.

A refrigeration apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of the refrigeration apparatus 1. The refrigeration apparatus 1 includes, for example, an outdoor unit 10 installed outside a store such as a convenience store, a plurality of refrigerated showcases 20 for storing refrigerated products installed in the store, and storage of frozen products installed in the store. The refrigeration showcase 30 for use, the first refrigerant circuit 40 through which the refrigeration side refrigerant flows to constitute the refrigeration cycle on the refrigeration showcase 20 side, and the refrigeration side refrigerant to constitute the refrigeration cycle on the refrigeration showcase 30 side The second refrigerant circuit 50 that circulates, the heat exchange unit 60 that exchanges heat between the refrigeration-side refrigerant and the refrigeration-side refrigerant, and a controller that controls the temperature, defrosting operation, and the like of the refrigeration showcase 20 and the refrigeration showcase 30. 70.

The outdoor unit 10 is configured by sequentially connecting a first compressor 12 and a first condenser 14 to the first refrigerant circuit 40 in the flow direction of the refrigeration-side refrigerant, and the first condenser 14 is refrigerated. A first condenser fan 16 is provided to exchange heat between the side refrigerant and the outside air.
The refrigerated showcase 20 includes a reach-in showcase 20a whose front is opened and closed by a glass door, and a plurality of open showcases 20b whose front is opened. Inside these showcases 20a and 20b, when viewed from the flow direction of the refrigeration-side refrigerant, the solenoid valves 22a and 22b, the first expansion valves 24a and 24b, and the first evaporator 26a are respectively connected to the first refrigerant circuit 40. , 26b are sequentially connected. The first evaporators 26a and 26b include first evaporator fans 28a and 28b for exchanging heat between the refrigeration-side refrigerant and the air in the refrigerated showcase 20, respectively.

  The refrigeration showcase 30 is a closed showcase whose front is opened and closed by a glass door. The refrigeration showcase 30 includes a second compression circuit 50 in the second refrigerant circuit 50 as viewed from the flow direction of the refrigeration-side refrigerant. The machine 32, the second expansion valve 34, and the second evaporator 36 are sequentially connected. The second evaporator 36 includes a second evaporator fan 38 that exchanges heat between the refrigeration-side refrigerant and the air in the refrigeration showcase 30.

In the heat exchange unit 60, an electromagnetic valve (first on-off valve) 62, a third expansion valve 64, and a cascade condenser (heat exchanger) 66 are provided in the first refrigerant circuit 40 in the flow direction of the refrigeration side refrigerant. Sequentially connected.
The cascade condenser 66 is a heat exchanger for exchanging heat between the refrigeration side refrigerant and the refrigeration side refrigerant, and inside thereof, a refrigeration side path (evaporation side path) 66a to which the first refrigerant circuit 40 is connected, A refrigeration side path (condensation side path) 66b to which the second refrigerant circuit 50 is connected is arranged. The refrigeration side path 66b is disposed between the second compressor 32 and the second expansion valve 34 in the second refrigerant circuit 50, and as shown in FIG. Heat exchange is performed in a counterflow with the refrigerant. The first refrigerant circuit 40 is configured by sequentially connecting the outdoor unit 10, the heat exchange unit 60, the reach-in showcase 20a, and each open showcase 20b in parallel, and the refrigeration-side refrigerant circulates in parallel therewith at various places. Heat exchange takes place.

On the other hand, the second refrigerant circuit 50 is built in the refrigeration showcase 30 and performs heat exchange in the refrigeration showcase 30, and the refrigeration side refrigerant and the refrigeration side via the heat exchange unit 60, that is, the cascade condenser 66. Heat exchange with the refrigerant is performed.
The control unit 70 is composed of a microcomputer, and in addition to the electromagnetic valves 22a, 22b and 62, the first condenser fan 16, the first evaporator fans 28a and 28b, and the second evaporator fan 38, illustration is omitted. However, temperature sensors 72 and 74 for detecting the temperature of air in the refrigerated / frozen showcases 20 and 30 are electrically connected.

By the way, the cascade condenser 66 constitutes the heat exchange unit 60 to exchange heat between the refrigeration-side refrigerant and the refrigeration-side refrigerant to condense the refrigeration-side refrigerant, and also by the cold storage heat from the refrigeration-side refrigerant using water. The refrigerant on the freezing side is condensed.
Specifically, referring to the enlarged perspective view of the cascade condenser 66 shown in FIG. 2, the refrigeration side path 66a is bent in a U-shape, and its convex portion is arranged on the lower side, while the refrigeration side path 66b. Is also bent into a U-shape, and is fixed in contact with the convex portion of the refrigeration side path 66a in such an arrangement that the convex portion is on the upper side.

Here, most of the contact between these convex portions is housed in a case 82 surrounding the refrigeration side path 66a and the freezing side path 66b in an airtight manner.
The case 82 is formed in a rectangular parallelepiped having a predetermined capacity, and a water supply pipe (water supply port) 84 and a drain pipe (drainage port) 86 are connected to the lower surface 82a and the upper surface 82b of the rectangular parallelepiped in the vicinity of the left surface 82c and the right surface 82d, respectively. Has been. The case 82 is heat-insulated to prevent condensation on the outer surface including these surfaces 82a to 82d.

When city water is supplied to the water supply pipe 84 and the level of the city water rises in the case 82 and becomes full, it is discharged from the drain pipe 86 and collected separately. In addition, an electromagnetic valve (second on-off valve) 88 is connected to the drain pipe 86 so that the flow of water in the case can be shut off. The electromagnetic valve 88 may be installed in the water supply pipe 84.
Storage and distribution of water in the case 82 is performed by operating a water tap and an electromagnetic valve 88 (not shown) for supplying city water. The case 82 may be provided with a water supply port or drainage port that can be closed with a lid, and a water supply hose may be inserted into these water supply ports to supply water into the case 82, or manually by a water supply / drainage valve device or the like. Water may be automatically supplied into the case 82.

As described above, the water path 90 of the water flowing from the water supply pipe 84 to the drain pipe 86 is formed in the case 82, and the refrigerant flowing through the freezing side path 66b and the water flowing through the water path 90 form a counter flow. Heat exchange. In addition, a water temperature sensor 91 (not shown) that detects the temperature of water in the case 82 is installed in the case 82 and is electrically connected to the control unit 70.
Hereinafter, the cooling operation in the refrigeration / freezing showcases 20 and 30 of the refrigeration apparatus 1 will be described.

The refrigeration-side refrigerant discharged from the first compressor 12 flows through the first condenser 14, and then passes through the electromagnetic valves 22a and 22b, the first expansion valves 24a and 24b, and the first evaporators 26a and 26b. On the other hand, the refrigerant flows through the refrigeration side path 66 a via the electromagnetic valve 62 and the third expansion valve 64, and is sucked into the first compressor 12.
The refrigeration side refrigerant discharged from the second compressor 32 flows through the refrigeration side path 66 b, the second expansion valve 34, and the second evaporator 36, and is sucked into the second compressor 32.

As the refrigerant circulates through the first and second refrigerant circuits 40 and 50 in this way, in the cascade condenser 66, the refrigeration side refrigerant evaporates in the refrigeration side path 66a and the refrigeration side refrigerant in the refrigeration side path 66b. As a result, the refrigerant in the first refrigerant circuit 40 and the refrigerant in the second refrigerant circuit 50 exchange heat.
Here, in order to evaporate the refrigeration side refrigerant flowing through the refrigeration side path 66a by the water stored in the case 82 by closing the electromagnetic valve 88, the refrigeration side refrigerant is added to the cold heat of the stored water. The latent heat of water when the water absorbed by the evaporation of water freezes and changes to ice is also used. Since this ice plays a role as a cold storage agent, even if the first refrigerant circuit stops due to the formation of ice, the refrigerant on the refrigeration side flowing through the refrigeration side path 66b is condensed, and the second refrigerant circuit is operated. be able to.

Specifically, the control unit 70 turns off the electromagnetic valve 62 and closes it in accordance with the defrosting operation of the refrigerated showcase 20 or the state of the heat load of the first refrigerant circuit, and the refrigeration side path 66a. Refrigeration-side refrigerant control is performed so that no refrigerant flows through.
Hereinafter, with reference to the flowchart shown in FIG. 3, a control routine related to the refrigeration side refrigerant control performed by the control unit 70 will be described.

  First, when the present control routine is started, it is determined in S1 (S represents a step, the same applies hereinafter) whether or not a defrosting time set in advance at a predetermined cycle has come. If the determination result is true (Yes) and it is determined that the defrost time has arrived, the process proceeds to S2, and if the determination result is false (No) and it is determined that the defrost time has not arrived, Shifts to S3.

When the process proceeds to S2, the solenoid valves 22a and 22b are turned off and closed, and then the process proceeds to S4.
In S4, after the electromagnetic valve 62 is turned off and closed, the process proceeds to S5.
In S5, it is determined whether or not the defrosting is finished. If the determination result is true (Yes) and it is determined that the defrosting is completed, the process proceeds to S6. If the determination result is false (No) and it is determined that the defrosting is not completed, the process returns to S5. Transition.

  In S6, pull-down of the first refrigerant circuit is started, and this control routine is returned. Pull-down refers to the process of opening and closing the solenoid valves 24a, 24b, 62 after defrosting, or the chamber temperature at a predetermined time from the end of defrosting secured in advance. In order to return the temperature to the evaporation set temperature in a short time, for example, a process of slightly lowering the evaporation set temperature of the evaporators 26a and 26b.

On the other hand, when it transfers to S3, it is determined whether the 1st refrigerant circuit is pulling down. When it is determined that the determination result is true (Yes) and the first refrigerant circuit is being pulled down, the process proceeds to S3 again, and the determination result is false (No) and the first refrigerant circuit is not being pulled down. If it is determined, the process proceeds to S7.
When the process proceeds to S7, it is determined whether or not the temperature T in the refrigerated showcase 20 detected by the temperature sensor 72 is 2 ° C. or more higher than a preset set temperature TS. If the determination result is true (Yes) and the temperature in the refrigerated showcase 20 is determined to be 2 ° C. or more higher than the preset set temperature, the process proceeds to S8, and the determination result is false (No) and the refrigerated showcase If it is determined that the temperature in 20 is not higher than the preset temperature by 2 ° C. or more, that is, the temperature rise in the refrigerated showcase 20 from the preset temperature is less than 2 ° C., the process proceeds to S9.

  When the process proceeds to S8, it is determined whether or not the inverter maximum rotational speed NM of the first compressor 12 continues for 5 minutes or more. If it is determined that the determination result is true (Yes) and the maximum rotation speed NM continues for 5 minutes or more, the process proceeds to S10, and the determination result is false (No) and the maximum rotation speed NM continues for 5 minutes or more. If it is not determined that the continuation of the maximum rotational speed NM is less than 5 minutes, the process proceeds to S9.

When the process proceeds to S10, the control routine is returned after the electromagnetic valve 62 is turned off and closed.
On the other hand, when the process proceeds to S9 in S7 or S8, the solenoid valve 62 is always turned on so that the temperature T in the refrigerated showcase 20 detected by the temperature sensor 72 is set to a preset temperature TS. In the opened state, the normal operation of opening and closing the electromagnetic valves 22a and 22b is continued and this control routine is returned.

Thus, when the defrosting time of the first refrigerant circuit 40 has come, the first refrigerant circuit 40 is stopped by closing the electromagnetic valves 22a, 22b, 62, while the first refrigerant circuit 40 When it is not the defrosting time, when the peak heat load of the first refrigerant circuit is confirmed, the heat capacity in the first refrigerant circuit is ensured by closing only the electromagnetic valve 62.
Next, the control unit 70 prevents the water temperature in the case 82 from rising by passing water through the case 82 even when, for example, all the ice formed in the case 82 has melted. Therefore, water flow control is implemented.

Hereinafter, with reference to the flowchart shown in FIG. 4, a control routine related to water flow control performed by the control unit 70 will be described.
First, when this control routine is started, it is determined in S11 whether or not the water temperature TW in the case 82 detected by the water temperature sensor 91 is 15 ° C. or higher. If the determination result is true (Yes) and the water temperature in the case 82 is determined to be 15 ° C. or higher, the process proceeds to S12, and the determination result is false (No) and the water temperature in the case 82 is less than 15 ° C. If it is determined, the process proceeds to S13.

When the process proceeds to S12, the electromagnetic valve 88 is turned on to open, and the present control routine is returned.
On the other hand, when the routine proceeds to S13, the electromagnetic valve 88 is turned off and closed, and this control routine is returned.
Thus, when the water temperature in the case 82 is 15 ° C. or higher, it is determined that all the ice formed in the case 82 has melted and the water temperature in the case 82 has begun to rise above room temperature. By simply passing water through the case 82, the water temperature in the case 82 can be kept below a water supply temperature generally considered to be normal temperature.

  Thus, according to the refrigeration apparatus 1 of the present embodiment, water is supplied to the case 82 in which the refrigeration side path 66a and the refrigeration side path 66b are accommodated via the water supply pipe 84 and drained via the drain pipe 86. The refrigerant flowing through the freezing side path 66b is condensed using the cold heat of water. Accordingly, the first refrigerant circuit 40 and the second refrigerant circuit 50 can be operated independently without separately installing a condenser in the second refrigerant circuit 50, so that the second refrigerant circuit 50. As a result, energy saving of the refrigeration apparatus 1 can be realized while reducing the equipment cost and space saving of the refrigeration apparatus 1.

Moreover, the excess cooling capacity of the first refrigerant circuit 40 can be stored in water by bringing the refrigeration side path 66a into contact with water.
Further, by using the cascade condenser 66 as a water-cooled condenser, it is possible to improve the cooling efficiency of the refrigerant flowing through the refrigeration side path 66b as compared with a general air-cooled condenser. Thus, energy saving of the refrigeration apparatus 1 can be further promoted.

Furthermore, since the cooling efficiency in the refrigeration side path 66b is improved, the amount of heat exchange per unit heat transfer area in the cascade condenser 66 is increased, so that the refrigeration side path 66b and thus the cascade condenser 66 are relatively downsized. As a result, space saving of the refrigeration apparatus 1 can be further promoted.
Further, by closing the electromagnetic valve 88, water can be stored in the case 82, and the excess cooling capacity of the first refrigerant circuit 40 can be effectively stored in water.

  Specifically, the case 82 has a predetermined capacity corresponding to the stop frequency and stop time of the first refrigerant circuit 40 to ensure the ability to store water in the case 82, thereby removing the first refrigerant circuit 40. Even if the first refrigerant circuit 40 is stopped due to frost, during the defrosting operation of the first refrigerant circuit 40, the second refrigerant circuit 50 can be operated independently while ensuring its cooling capacity, The reliability of the refrigeration apparatus 1 can be improved.

Further, the cascade condenser 66 is configured so that the water flowing in the case 82 counterflows with the refrigerant flowing in the freezing side path 66b. Thereby, the heat exchange efficiency of the water which distribute | circulates the inside of case 82, and the refrigerant | coolant which distribute | circulates the freezing side path | route 66b can improve, and the energy-saving of the freezing apparatus 1 can further be accelerated | stimulated.
Further, the water supply pipe 84 is formed in the lower part of the case 82 and the drain pipe 86 is formed in the upper part of the case 82, so that water can be easily stored in the case 82, and at this time, an air pool in the case 82 is stored. Can be reliably prevented, so that the heat exchange efficiency between the water flowing through the case 82 and the refrigerant flowing through the refrigeration side path 66a, and thus the refrigerant flowing through the refrigeration side path 66b, can be improved. It can be further promoted.

Further, the cascade condenser 66 is configured so that the refrigerant that flows through the refrigeration side path 66a and the refrigerant that flows through the refrigeration side path 66b flow in opposite directions, and thus circulates between the refrigeration side path 66a and the refrigeration side path 66b. The heat exchange efficiency between the refrigerants is improved, and energy saving of the refrigeration apparatus 1 can be further promoted.
Furthermore, the cascade condenser 66 is arranged such that the refrigeration side path 66a and the refrigeration side path 66b are in contact with each other, thereby improving the heat exchange efficiency between the refrigerants flowing through the refrigeration side path 66a and the refrigeration side path 66b. Further, energy saving of the refrigeration apparatus 1 can be further promoted.

  In addition, when the refrigeration side refrigerant control is performed by the control unit 70, the electromagnetic valve 62 that opens and closes the inlet of the refrigeration side path 66a is closed during the defrosting operation of the first refrigerant circuit 40. Thereby, since the refrigerant does not flow into the refrigeration side path 66a, the refrigerant flowing through the refrigeration side path 66b can be condensed only by the ice formed in the case 82, and the operation of the first refrigerant circuit 40 can be performed. Can be stopped. Therefore, the power loss of operating the first refrigerant circuit 40 during the defrosting operation of the first refrigerant circuit 40 is eliminated, and energy saving of the refrigeration apparatus 1 can be further promoted.

  Further, in the refrigeration side refrigerant control, when the maximum inverter rotation speed NM of the first compressor 12 continues for 5 minutes or more and the thermal load of the first refrigerant circuit 40 becomes excessive, the electromagnetic valve 62 is closed. . As a result, since the refrigerant does not flow through the refrigeration side path 66a during peak heat load of the first refrigerant circuit 40 especially during the daytime in summer, heat exchange between the refrigerants flowing through the refrigeration side path 66a and the refrigeration side path 66b. Is blocked, the cooling capacity of the first refrigerant circuit 40 can be reliably ensured, and the reliability of the refrigeration apparatus 1 can be improved.

  Furthermore, when the control unit 70 performs water flow control, the temperature of the water detected by the water temperature sensor 91 is 15 ° C. or higher, that is, the normal temperature or higher, in other words, the water supply temperature of the water flowing through the water supply pipe 84. When it becomes above, the solenoid valve 88 which opens and closes the drain pipe 86 is opened. As a result, even if the ice formed in the case is used for all the condensation of the refrigerant flowing through the refrigeration side passage 66b and melted, the water supplied through the case 82 is supplied by the refrigerant flowing through the refrigeration side passage 66a. It can prevent that it heats above. Accordingly, since the water in the case 82 can be automatically held at a temperature lower than the water supply temperature, the refrigerant flowing through the freezing side path 66b can be reliably condensed. Even if the refrigerant circuit 40 is stopped for a long time, the second refrigerant circuit 50 can be operated independently while ensuring its cooling capacity, and the reliability of the refrigeration apparatus 1 can be further improved.

The description of one embodiment of the present invention is finished above, but the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, as shown in a perspective view of a cascade condenser (heat exchanger) 92 in FIG. 5 as a modification, a circulation path 94 for circulating water in the case 82 and a pump 96 may be provided (stirring means). In this case, by closing the solenoid valves 62 and 88 and operating the pump 96, the cold heat of the water stored by the refrigerant flowing through the refrigeration side path (evaporation side path) 92a is distributed throughout the case 82. Can be made. Therefore, the heat exchange efficiency between the water flowing through the case 82 and the refrigerant flowing through the refrigeration side path (condensation side path) 92b can be improved, and the energy saving of the refrigeration apparatus 1 can be further promoted.

Moreover, since the amount of heat exchange per unit heat transfer area in the cascade condenser 92 is increased, the capacity of the case 82 can be relatively reduced, and the space saving of the refrigeration apparatus 1 can be further promoted. The same effect as described above can be obtained by providing a stirring fan (not shown) that stirs the water in the case 82 instead of the circulation path 94 and the pump 96.
As another modified example, as shown in the schematic cross-sectional view of the cascade condenser (heat exchanger) 98 in FIG. 6, a refrigeration side path (evaporation side path) 98a and a refrigeration side path (condensation side path) in the case 82. 98b may be arranged in a zigzag manner and then spaced apart. Accordingly, since the heat transfer area between the ice formed in the case 82 and the refrigeration side path 98a can be increased by closing the electromagnetic valve 88, the refrigerant flowing through the refrigeration side path 98a and the case 82 The efficiency of heat exchange with the formed ice is improved, and energy saving of the refrigeration apparatus 1 can be further promoted. In this case, it is preferable that the pump 96 is always operated.

In addition, although illustration is abbreviate | omitted, the refrigeration side path | route 98a and the freezing side path | route 98b are formed in cross sectional view substantially elliptical shape, and distribute | circulates the freezing side path | route 98b by arrange | positioning these elliptical flat surfaces mutually opposed. It is possible to improve not only the refrigerant and ice formed in the case 82 but also the heat exchange efficiency between the refrigerants flowing through the refrigeration side path 98a and the refrigeration side path 98b.
Furthermore, as shown in the schematic diagram of the cascade capacitor 100 of FIG. 7 as another modified example, only the refrigeration side path (evaporation side path) 100a is accommodated in the case (first case) 82, A water circuit 104 provided with a new case (second case) 102 that exchanges heat with the refrigerant flowing through the refrigeration side path (condensation side path) 100b may be provided outside. This cascade condenser 100 is specialized in the function as a so-called water-cooled condenser, but at least promotes energy saving of the refrigeration apparatus 1 by storing the excess cooling capacity of the first refrigerant circuit 40 in water. However, the reliability can be ensured. Also in this case, it is preferable that the pump 96 is always operated.

  Finally, in the above-described embodiment and each modification, the refrigeration apparatus 1 for cooling the refrigerated showcase 20 and the freezer showcase 30 is shown. However, the refrigerator, the freezer, or the air conditioner is not limited to the refrigerated showcase 20 and the freezer showcase 30. You may use for freezing apparatuses, such as.

It is a schematic block diagram of the freezing apparatus which shows one Embodiment of this invention. It is the perspective view which showed the cascade capacitor | condenser of FIG. It is the flowchart which showed the control routine of the refrigerating side refrigerant | coolant control implemented by the control part of FIG. It is the flowchart which showed the control routine of the water flow control implemented by the control part of FIG. It is the perspective view which showed the modification of the cascade capacitor. It is the schematic sectional drawing which showed the modification of the cascade capacitor. It is the schematic diagram which showed the modification of the cascade capacitor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigeration apparatus 12 1st compressor 14 1st condenser 24a, 24b 1st expander 26a, 26b 1st evaporator 32 2nd compressor 34 2nd expander 36 2nd evaporator 40 First refrigerant circuit 50 Second refrigerant circuit 62 Solenoid valve (first on-off valve)
64 Third expander 66, 92, 98, 100 Cascade condenser (heat exchanger)
66a, 92a, 98a, 100a Refrigeration side path (evaporation side path)
66b, 92b, 98b, 100b Freezing side path (condensation side path)
70 Control unit 82 Case (first case)
82a Bottom (bottom)
82b Top (upper)
84 Water supply pipe (water supply port)
86 Drain pipe (drain)
88 Solenoid valve (second on-off valve)
91 Water temperature sensor 102 Case (second case)

Claims (13)

From the 1st refrigerant circuit which consists of the 1st compressor, the 1st condenser, the 1st expander, and the 1st evaporator, and the 2nd compressor, the 2nd expander, and the 2nd evaporator A second refrigerant circuit, and a heat exchanger that exchanges heat between the refrigerant of the first refrigerant circuit and the refrigerant of the second refrigerant circuit, and discharged from the first condenser A part of the refrigerant is evaporated in the evaporation side path of the heat exchanger via a third expander provided on the inlet side of the heat exchanger, and the refrigerant discharged from the second compressor In the condensation side path of the heat exchanger,
The said heat exchanger condenses the refrigerant | coolant which distribute | circulates the said condensation side path | route using water.   The refrigerating apparatus according to claim 1, wherein the heat exchanger includes a case in which the evaporation side path and the condensation side path are accommodated and the water is stored.   The refrigeration apparatus according to claim 2, wherein the case includes a water supply port to which the water is supplied and a drain port from which the water is discharged.   The refrigeration apparatus according to claim 2 or 3, wherein the heat exchanger is configured so that water flowing through the case forms a counter flow with a refrigerant flowing through the condensing side flow path.   The refrigeration apparatus according to claim 3, wherein the water supply port is formed at a lower portion of the case, and the drain port is formed at an upper portion of the case.   The refrigeration apparatus according to any one of claims 2 to 5, wherein the heat exchanger includes stirring means for stirring water in the case.   The said heat exchanger is comprised so that the refrigerant | coolant which distribute | circulates the said evaporation side path | route and the refrigerant | coolant which distribute | circulates the said condensing side flow path may make counterflow, The one in any one of Claim 1 thru | or 6 characterized by the above-mentioned. Refrigeration equipment.   The refrigeration apparatus according to any one of claims 1 to 7, wherein the heat exchanger is disposed in contact with the evaporation side path and the condensation side path.   2. The heat exchanger according to claim 1, wherein the evaporation side passage and the condensation side passage are formed in an approximately elliptical shape in cross section, and the elliptical flat surfaces are arranged to face each other. The refrigeration apparatus according to claim 8. A first on-off valve that opens and closes the inlet of the evaporation side path; and a controller that is electrically connected to the first on-off valve;
The refrigeration apparatus according to any one of claims 1 to 9, wherein the control unit closes the first on-off valve during a defrosting operation of the first refrigerant circuit.   The case includes a first case in which the condensation side path is accommodated and a second case in which the evaporation side path is accommodated. The first case and the second case are pumps. The refrigeration apparatus according to claim 2 or 3, wherein the refrigeration apparatus is interposed in a water circuit provided.   The refrigerating apparatus according to claim 10, wherein the control unit closes the first on-off valve when a heat load of the first refrigerant circuit becomes a predetermined value or more. A water temperature sensor for detecting the temperature of water in the case, and a second on-off valve for opening and closing the water supply port or the drain port,
The said control part opens the said 2nd on-off valve, when the temperature of the water detected with the said water temperature sensor becomes more than the supply temperature of the water which distribute | circulates the said water supply port. The refrigeration apparatus described in 1.

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