JP5096678B2

JP5096678B2 - Refrigeration equipment

Info

Publication number: JP5096678B2
Application number: JP2006002977A
Authority: JP
Inventors: 修行井上
Original assignee: 株式会社荏原製作所
Priority date: 2006-01-10
Filing date: 2006-01-10
Publication date: 2012-12-12
Anticipated expiration: 2026-01-10
Also published as: CN101371082A; JP2007183077A; WO2007080994A1; CN101371082B

Description

The present invention relates to a refrigeration apparatus that uses a fluid that changes sensible heat as a cooling fluid (cooling source such as cooling water or cooling air) and uses a fluid that changes sensible heat such as cold water or brine as a cooled fluid. The present invention relates to a refrigeration apparatus having a plurality of refrigerators.

Conventionally, there is a refrigeration apparatus configured by installing a plurality of refrigerators including an evaporator, a compressor, a condenser, and the like. FIG. 19 is a block diagram illustrating an example of this type of refrigeration apparatus, and FIG. 20 is a diagram illustrating a supply state of cold water and cooling water in the refrigeration apparatus. The refrigeration apparatus shown in both figures includes two refrigerators 200-1 and 200-2, and evaporators 201-1 and 201-2, compressors 203-1 and 203-2, and a condenser 205, respectively. -1, 205-2 and expansion valves 207-1 and 207-2 are connected by refrigerant pipes 209-1 and 209-2 to constitute a closed system in which the refrigerant is circulated in a closed circuit.

Conventionally, cold water (cooled fluid) is supplied in parallel to each of the evaporators 201-1 and 201-2, and cooling water is supplied in parallel to each of the condensers 205-1 and 205-2. (Cooling fluid) was being supplied. According to this cooling water and cooling water supply method, when the refrigerating capacity is small, it is possible to control the number of the refrigerators 200-1 and 200-2 to be operated, and the cooling water and the cooling water are also adapted to the capacity. It has the feature that it can be increased or decreased and can handle partial loads.

However, on the other hand, in the conventional refrigeration apparatus, the evaporators 201-1 and 201-2 and the condensers 205-1 and 205 of the stopped refrigerators 200-1 and 200-2 at the time of partial load (unit number control). Since -2 is suspended, there is a problem in that these cannot contribute to heat transfer and efficiency cannot be improved at the time of partial load of the refrigeration apparatus.
JP2003-130428

The present invention has been made in view of the above points, and an object of the present invention is a refrigeration apparatus using a plurality of refrigerators, which improves efficiency at the time of full load and a plurality of evaporators even in the case of partial load. An object of the present invention is to provide a refrigeration apparatus capable of maintaining high partial load efficiency while always using a condenser.

The present invention includes at least an evaporator that takes heat from a fluid to be cooled and evaporates the refrigerant to exert a refrigeration effect, a compressor that compresses the refrigerant vapor into high-pressure steam, and cools the high-pressure steam with a cooling fluid. the refrigerator having a condenser for condensing comprises two Te, the fluid to be cooled are connected in series to the evaporator of said two refrigerators are sequentially cooled by two evaporators of the refrigerant evaporation heat the cooling fluid is connected in series with the condenser of the two refrigerators, successively two condensers of the refrigerant is cooled, driving each compressor of the two chiller same motor And a labyrinth seal as a seal between the electric motor and the compressors, and an open / close valve for the condenser of one of the two refrigerators and the evaporator of the other refrigerator. Connected with the first pipe and the condenser of the other refrigerator and one The evaporator of the refrigerator is connected by a second pipe having an on-off valve, and the refrigerant bias between the two refrigerators is eliminated by opening / closing control of the on-off valve of the first pipe and the on-off valve of the second pipe. In the refrigeration apparatus, the refrigerant bias eliminating means is provided .

Further, the invention of the present application is the above-described refrigeration apparatus, wherein at least the evaporators of the two refrigerators are installed in respective sections dividing one can body, or the condensers of the two refrigerators are installed. It is characterized by being installed in each section into which one can body is partitioned.

Further, the present invention, in the above-mentioned refrigeration system, the a in the evaporator while a refrigerant pipe connecting the respective condensers of the two refrigerators, power recovery to recover energy of the flow of refrigerant to the evaporator from the condenser An expander is provided.

Further, the invention of the present application is characterized in that, in the refrigeration apparatus, the power recovery expander recovers power by driving a generator by energy of a refrigerant flow.

According to the present invention, the fluid to be cooled is connected in series to the evaporators of the plurality of refrigerators, and the cooling fluid is connected in series to the condensers of the plurality of refrigerators. Utilizing the sensible heat change of the cooling fluid, the efficiency at the full load and the efficiency at the partial load can both be maintained high, and from these, the efficiency of the entire refrigeration apparatus can be improved. In addition, the compressor of the two refrigerators is configured to be driven by the same motor, and a labyrinth seal with a simple configuration is employed for the seal between the motor and both compressors, thereby simplifying the compressor structure. of the Ru Hakare. Further, by sealing the gap between the electric motor and both compressors with a labyrinth seal, there may be a refrigerant bias between the two refrigerators. This is caused by the condenser of one refrigerator and the other refrigerator. Thus, the effect of eliminating the non-uniformity of the evaporator by a refrigerant bias eliminating means having a simple configuration in which the evaporator is connected by a pipe having an on-off valve is obtained.

According to the invention of the present application, at least the evaporators of two refrigerators are installed in the respective sections dividing one can body, or the condensers of two refrigerators are installed in one can body. Therefore, the evaporator structure and / or the condenser structure can be simplified.

Further, according to the present invention, the refrigerant pipe connecting between the respective condenser two refrigerator evaporator, power recovery expander for recovering energy of the flow of refrigerant to the evaporator from the condenser is provided Therefore, power (energy of the refrigerant flow from the condenser to the evaporator) can be recovered during expansion of the refrigerant, and at the same time, the cooling effect can be increased.

Further, according to the present invention, the power recovery expander recovers power by driving the generator with the energy of the refrigerant flow, so that the rotational speed of the power recovery expander depends on the amount of electricity extracted (the amount of generated power). The rotational speed of the power recovery expander can be easily controlled.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Since the refrigerator according to the present invention is composed of a plurality of refrigerators (compression refrigerators that perform a vapor compression refrigeration cycle), a specific example of a refrigerator alone used in the present invention will be described in advance. 2, 4, and 6 are configuration diagrams showing refrigerators 20, 20 A, and 20 B that can be used in the refrigeration apparatus of the present invention, and FIGS. 1, 3, and 5 are respectively refrigerators 20, 20 A, It is a figure which shows the refrigerating cycle of 20B. The refrigerator 20 shown in FIG. 2 is configured by a closed system in which a refrigerant is enclosed. Specifically, an evaporator 21 that takes heat from cold water (a fluid to be cooled) and evaporates the refrigerant to exert a refrigeration effect; A compressor 23 that compresses the refrigerant vapor into high-pressure steam; a condenser 25 that cools and condenses the high-pressure steam with cooling water (cooling fluid); and an expansion valve 27 that decompresses and expands the condensed refrigerant. Are connected by a refrigerant pipe 29.

The refrigerator 20A shown in FIG. 4 is also configured by a closed system in which a refrigerant is enclosed. The difference from the refrigerator 20 shown in FIG. 2 is that the condenser 25 is more efficient than the refrigerator 20 in order to achieve higher efficiency. A plurality of (two) economizers (gas-liquid separators) 31 and 31 ′ are installed between the evaporator 21 and the evaporator 21, and the compressors 23, 23 ′ and 23 ″ are multistage (three stages) to perform compression. This is the point where refrigerant vapor from the economizers 31 and 31 'is sucked in the middle of the stage, thereby forming a two-stage economizer cycle as shown in Fig. 3. Between the condenser 25 and the economizer 31, In general, an expansion valve is provided between the economizer 31 and the economizer 31 ', and between the economizer 31' and the evaporator 21. In addition, the economizer 31 'and the evaporator 21 are provided in FIG. Only during It shows the valve 27.

The economizer cycle includes a single-stage economizer that combines two stages of compressors and one economizer, or an N-stage economizer cycle that combines compressors (N + 1) and N economizers. Efficiency increases as the number of stages increases. For application of the present invention, a single-stage or N-stage economizer may be used instead of the two-stage economizer shown in FIG.

Further, the refrigerator 20B shown in FIG. 6 is also configured by a closed system in which a refrigerant is sealed. The difference from the refrigerator 20 shown in FIG. 2 is that a power recovery expander 28 is attached instead of the expansion valve 27. It is. The power recovery expander 28 expands the condensate and sends it to the evaporator 21 and recovers the power by the power recovery machine (generator) 281. If comprised in this way, like the line segment a1 shown in FIG. 5, an enthalpy will fall at the time of expansion | swelling, and power (energy which the flow of the refrigerant | coolant from the condenser 25 to the evaporator 21) can be collect | recovered, At the same time The freezing effect increases by the amount. In the case of this refrigerator 20B, the efficiency can be improved to the same extent as in the case of the refrigerator 20A shown in FIG. 4, and the structure is simplified because it is not necessary to install the compressors 23 in multiple stages. As in this embodiment, it is desirable that the recovered power is recovered as electricity, and the recovered power is used as a part of the driving power of the compressor 23, or a refrigeration such as a cold water pump, a cooling water pump, a cooling tower, etc. It is used as a part of auxiliary drive power of the apparatus, or used as various equipment drive power unrelated to the refrigeration apparatus in conjunction with other power systems. Further, when the generator 281 is used for the power recovery expander 28 as in this embodiment, the rotational speed of the power recovery expander 28 can be changed depending on the amount of electricity extracted, and the rotational speed control of the power recovery expander 28 is controlled. Becomes easier.

The power recovery cycle of FIG. 6 is provided with a power recovery expander 28 instead of the expansion valve 27 of FIG. 2. For example, in the single stage economizer cycle, between the condenser 25 and the economizer 31 and Efficiency may be improved as a power recovery cycle in which a power recovery expander 28 is provided between the economizer 31 and the evaporator 21, and the present invention may be applied.

FIG. 7 is a configuration diagram showing the refrigeration apparatus according to the first embodiment of the present invention, and FIG. 8 is a diagram showing a supply state of cold water and cooling water in the refrigeration apparatus. The refrigeration apparatus shown in both figures includes two refrigeration machines 20-1 and 20-2 having the same configuration as the refrigeration machine 20 shown in FIG. 2, and each of the refrigeration machines 20-1 and 20-2 as described above. Are each composed of a closed system filled with a refrigerant, evaporators 21-1, 21-2, compressors 23-1, 23-2, condensers 25-1, 25-2, and expansion valve 27-. 1 and 27-2 are connected by refrigerant pipes 29-1 and 29-2.

And the cold water (cooled fluid) supplied to this refrigeration apparatus is connected in series to each evaporator 21-1, 21-2 of each refrigerator 20-1, 20-2 by piping 41, and this Cooling water (cooling fluid) supplied to the refrigeration apparatus is also connected in series to the condensers 25-1 and 25-2 by the pipe 43. Accordingly, the cold water is sequentially cooled by the evaporating heat of the refrigerant in each evaporator 21-1, 21-2, and the cooling water sequentially cools the refrigerant vapor in each condenser 25-1, 25-2. In the case of this embodiment, the flow of cold water and cooling water is a parallel flow that flows in the same direction from the refrigerator 20-1 toward the refrigerator 20-2.

Thus, since cold water and cooling water were supplied to the some refrigerator 20-1, 20-2 in series, average evaporation temperature can be made high and average condensation temperature can be made low. That is, the head required for compression can be lowered, and the efficiency increases. The operation will be specifically described below. FIG. 9 is a diagram showing a refrigeration cycle of each of the refrigerators 20-1 and 20-2 of the refrigeration apparatus according to this embodiment, and FIG. 10 is a diagram of each refrigerator 200-1 of the conventional refrigeration apparatus shown in FIG. It is a figure which shows the refrigerating cycle of 200-2. Moreover, FIG. 11 is a figure which shows the evaporating temperature with respect to the cold water temperature of each refrigerator 20-1, 20-2 of the freezing apparatus concerning this embodiment, and the condensation temperature with respect to cooling water temperature, FIG. 12 is shown in the said FIG. It is a figure which shows the evaporating temperature with respect to the cold water temperature of each refrigerator 200-1, 200-2 of the conventional freezing apparatus, and the condensation temperature with respect to a cooling water temperature.

In the evaporators 21-1 and 21-2, a pinch temperature is formed by the cold water outlet temperature and the evaporation temperature, while in the condensers 25-1 and 25-2, the pinch temperature is configured by the condensation temperature and the cooling water outlet temperature. And in the case of the conventional freezing apparatus, since cold water and cooling water are supplied in parallel to each freezer 200-1 and 200-2, as shown in FIG. 10, the freezing cycle of freezer 200-1 and 200-2 As shown in FIG. 12, the pinch temperatures of the evaporators 201-1 and 201-2 and the condensers 205-1 and 205-2 are the same, and the evaporators 201-1 and 201-2 are the same. The temperature of the cold water passing through the condenser and the temperature of the cooling water passing through the condensers 205-1 and 205-2 are equivalent.

On the other hand, in the case of the above embodiment, cold water and cooling water are supplied in series (and parallel flow) to each of the refrigerators 20-1 and 20-2. Thus, the efficiency of the refrigeration cycle can be increased. That is, as shown in FIG. 11, by supplying cold water in series to each of the evaporators 21-1, 21-2 and supplying cooling water in series to each of the condensers 25-1, 25-2, both evaporators 21-1 and 21-2 and the condensers 25-1 and 25-2 are distributed with different pinch temperatures to raise the average evaporation temperature and lower the average condensation temperature. At this time, the temperature difference between the condensation temperature and the evaporation temperature shown in FIG. 12 is equivalent to the temperature difference between the condensation temperature on the condenser 25-2 side and the evaporation temperature on the evaporator 21-2 side shown in FIG. The temperature difference between the condensing temperature of the condenser 25-1 and the evaporating temperature of the evaporator 21-1 can be reduced as compared with the conventional case shown in FIG. 12, and the compression head (temperature head) required for the compression can be reduced accordingly. The required power of the compressor 23-1 can be reduced, and the efficiency of the refrigeration apparatus can be increased.

The above is the case of full load, but the partial load efficiency of the compressors 23-1, 23-2 is maintained (that is, the rotational speed control of the compressors 23-1, 23-2 is used and FIG. As shown, by providing suction guide vanes 23a-1 and 23a-2 at the inlets of the compressors 23-1 and 23-2, all the compressors 23-1 and 23-2 are highly efficient even at partial loads. Even if a partial load is reached, the heat transfer surfaces of all the evaporators 21-1, 21-2 and the condensers 25-1, 25-2 are used without being stopped. At that time, the flow rate of the cooling water and the flow rate of the cooling water may be controlled to a flow rate that matches the capacity by controlling the rotational speed of a pump that circulates these. That is, by making all the heat transfer surfaces of the evaporators 21-1, 21-2 and the condensers 25-1, 25-2 effective, the average evaporation temperature rises and the average condensation temperature decreases. However, also from this point, the number of compression heads (temperature heads) required for compression is reduced, the required power is reduced, and the efficiency is increased.

FIG. 13: is a figure which shows the supply state of the cold water and cooling water in the freezing apparatus concerning 2nd Embodiment of this invention. In the refrigeration apparatus shown in the figure, the same or corresponding parts as those in the refrigeration apparatus of the first embodiment shown in FIGS. Items other than those described below are the same as those in the first embodiment. In this embodiment, the difference from the first embodiment is only that the direction of supply of cold water and cooling water is different. That is, also in the refrigeration apparatus according to this embodiment, the supplied cold water (cooled fluid) is serially connected to the evaporators 21-1 and 21-2 of the refrigerators 20-1 and 20-2 by the pipe 41. The cooling water (cooling fluid) supplied to the refrigeration apparatus is also connected in series to the condensers 25-1 and 25-2 by the pipe 43, so that the cold water is supplied to each evaporator 21-1. , 21-2 are sequentially cooled by the heat of evaporation of the refrigerant in the refrigerant, and the cooling water sequentially cools the refrigerant vapor in the condensers 25-2 and 25-1. In this embodiment, the cold water is removed from the evaporator. The counter flow flows from 21-1 toward the evaporator 21-2, while the cooling water flows in the opposite direction from the condenser 25-2 toward the condenser 25-1.

Even if it comprises in this way, since it does not change in supplying cold water and cooling water to the some refrigerator 20-1, 20-2 in series, an average evaporation temperature is made high and an average condensation temperature is made low. Can do. That is, the compression head (temperature head) required for compression can be lowered, and the efficiency increases. The operation will be specifically described below. FIG. 14 is a diagram showing a refrigeration cycle of each of the refrigerators 20-1 and 20-2 of the refrigeration apparatus according to this embodiment. Moreover, FIG. 15 is a figure which shows the evaporating temperature with respect to the cold water temperature of each refrigerator 20-1, 20-2 of the freezing apparatus concerning this embodiment, and the condensation temperature with respect to cooling water temperature.

As described above, in the evaporators 21-1, 21-2, a pinch temperature is generated by the cold water outlet temperature and the evaporation temperature, while in the condensers 25-1, 25-2, the pinch temperature is determined by the condensation temperature and the cooling water outlet temperature. In the case of this embodiment, cold water and cooling water are supplied to each of the refrigerators 20-1 and 20-2 in series and in a counterflow, so that the sensible heat change of cold water and cooling water is used. Thus, the efficiency of the refrigeration cycle can be increased. That is, as shown in FIG. 15, by supplying cold water in series to each of the evaporators 21-1, 21-2, the pinches in both the evaporators 21-1, 21-2 and the condensers 25-1, 25-2 are pinched. It is dispersed at different temperatures, raising the average evaporation temperature and lowering the average condensation temperature. At this time, the condensation temperature of the conventional example shown in FIG. 12 is equivalent to the condensation temperature of the condenser 25-2 shown in FIG. 15, and the evaporation temperature of the conventional example shown in FIG. 12 is the same as that of the evaporator 25-1 shown in FIG. Equivalent to the evaporation temperature. That is, the condensation temperature of the condenser 25-1 shown in FIG. 15 decreases, and the evaporation temperature of the evaporator 25-2 shown in FIG. 15 increases. That is, the temperature difference between the condensation temperature of the condenser 25-1 and the evaporation temperature of the evaporator 21-1 and the temperature difference between the condensation temperature of the condenser 25-2 and the evaporation temperature of the evaporator 21-2 shown in FIG. Both can be made smaller than in the case of the conventional example shown in FIG. 12, and the compression heads (temperature heads) required for compression can be reduced in both compressors 23-1, 23-2. The required power of -1,23-2 can be reduced, and the efficiency of the refrigeration apparatus can be increased.

FIG. 16 is a configuration diagram of a refrigeration apparatus according to a third embodiment of the present invention, and FIG. 17 is a diagram illustrating a supply state of cold water and cooling water in the refrigeration apparatus. The refrigeration apparatus shown in both figures includes two refrigerators 20B-1 and 20B-2 having the same configuration as the refrigerator 20B shown in FIG. 6, and each of the refrigerators 20B-1 and 20B-2 as described above. Are each composed of a closed system filled with a refrigerant, evaporators 21-1, 21-2, compressors 23-1, 23-2, condensers 25-1, 25-2, and a power recovery expander. 28-1 and 28-2 are connected by refrigerant pipes 29-1 and 29-2. In the case of this embodiment, the electric motor M that drives the two compressors 23-1 and 23-2 is shared to simplify the electrical instrumentation. The motor M is a hermetically sealed type, moves in a refrigerant atmosphere, and a labyrinth seal is provided between the motor M and the compressors 23-1 and 23-2. By the way, when two compressors 23-1, 23-2 are connected to one electric motor M as in this embodiment, one refrigerator 20B-1 or 20B-2 to the other refrigerator 20B-2 or 20B. The refrigerant may leak toward -1, and when this refrigeration apparatus is operated for a long time, the refrigerant may be biased into any of the refrigerators 20B-1 or 20B-2. Therefore, in this embodiment, the condenser 25-1 of one refrigerator 20B-1 and the evaporator 21-2 of the other refrigerator 20B-2 and the condenser 25-2 of the other refrigerator 20B-2 and one of them. The evaporator 21-1 of the refrigerator 20 B- 1 is connected by a pipe 33 having an open / close valve 35 so as to eliminate the bias. Specifically, the liquid level rise of the condenser 25-1 or 25-2 is measured to detect excess refrigerant, and the on-off valve of the pipe 33 on the side connected to the condenser 25-1 or 25-2 35 is opened and an excessive amount of refrigerant liquid is sent to the other evaporator 21-2 or 21-1. Since the pressure of the condenser 25-1 or 25-2 is higher than that of the evaporator 21-2 or 21-1, the refrigerant liquid can be easily moved. In addition, since the whole refrigerant | coolant amount with which the freezing apparatus is filled is constant, if the initial filling amount is appropriate, the refrigerant | coolant of the refrigerator 20B-1 or 20B-2 of the excess side will be used as the other freezer 20B-2. Or if it sends to 20B-1 and the bias of a refrigerant | coolant is eliminated, the quantity of the refrigerant | coolant of the other refrigerator 20B-2 or 20B-1 will also be corrected.

In this embodiment, the evaporators 21-1 and 21-2 of the two refrigerators 20 B- 1 and 20 B- 2 constituting the refrigeration apparatus include a plurality of (two) one can bodies 37. Compartment, each heat transfer surface (heat transfer tube) is installed in the partitioned part, and at the same time, each of the condensers 25-1 and 25-2 is divided into a plurality of (two) one can body 39 And each heat transfer surface (heat transfer tube) was installed in the divided part. If comprised in this way, size reduction of a freezing apparatus can be achieved. The can body may be applied to only one of the evaporators 21-1, 21-2 or the condensers 25-1, 25-2.

In the third embodiment, each of the power recovery expanders 28-1 and 28-2 installed for a plurality of (two) refrigerators 20B-1 and 20B-2 has a separate generator (see FIG. 6). The power recovery machine 281) shown is connected, but a generator (power recovery machine) is connected to a plurality of power recovery expanders 28-1 and 28-2 to share the generator. You may do it.

FIG. 18 is a configuration diagram of a modified example of the refrigeration apparatus according to the third embodiment. In the refrigeration apparatus shown in the figure, the same or corresponding parts as those of the refrigeration apparatus of the third embodiment are denoted by the same reference numerals. Items other than those described below are the same as those in the third embodiment. The refrigeration apparatus shown in the figure is different from the refrigeration apparatus according to the third embodiment in that two stages of compressors 23-1 and 23-2 are provided on both sides of one electric motor M to constitute the refrigeration apparatus. The two refrigerators 20B-1 and 20B-2 are provided with economizers 31-1 and 31-2, respectively, between the condensers 25-1 and 25-2 and the economizers 31-1 and 31-2, And it is the point which set it as the structure which provided the motive power collection | recovery expanders 28-1 and 28-2 between the economizers 31-1, 31-2 and the evaporators 21-1, 21-2, respectively. In this way, the power recovery expanders 28-1 and 28-2 may be provided in a plurality of stages, and the power recovery cycle may be configured in multiple stages. Note that the refrigerant amount adjustment circuit corresponding to the pipe 33 having the on-off valve 35 shown in FIGS. 16 and 17 of the third embodiment is omitted in FIG.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited. For example, in the above embodiment, one refrigeration apparatus is configured by two refrigerators, but one refrigeration apparatus may be configured by three or more refrigerators. In that case, cold water (cooled fluid) is connected in series to each evaporator of the plurality of refrigerators, and cooling water (cooling fluid) is connected in series to each condenser of the plurality of refrigerators. Shed.

Further, in the above embodiment, the two compressors of the two refrigerators are configured to be driven by one electric motor. However, when one refrigerator is configured by three or more refrigerators, each refrigerator The compressor may be driven by one or two or more electric motors. In each of the above embodiments, the example in which the refrigerator 20 shown in FIG. 2 and the refrigerator 20B shown in FIG. 6 are used as the refrigerator used in the refrigeration apparatus has been described. Of course, the refrigerator 20A shown in FIG. 4 may be used. . Furthermore, you may use the refrigerator which has structures other than these refrigerator 20,20A, 20B.

In the above embodiment, two compressors of two refrigerators are configured to be driven by one electric motor. However, as shown in FIG. 7, an electric motor is provided in each compressor, and the load is extremely reduced. In some cases or when surging occurs, the number of compressors may be controlled. That is, in general, it is more efficient to use the entire heat transfer area of the evaporator and condenser, but when the load is extremely small and the efficiency of the compressor is significantly reduced, the heat transfer area is at least compressed. In some cases, it may be better to increase the refrigerant flow rate per machine. It is also possible to control the number of units by comparing the efficiency by calculation.

It is a figure which shows the refrigerating cycle of the refrigerator. FIG. 3 is a configuration diagram of a refrigerator 20. It is a figure which shows the refrigerating cycle of 20 A of refrigerators. It is a block diagram of refrigerator 20A. It is a figure which shows the refrigerating cycle of refrigerator 20B. It is a block diagram of refrigerator 20B. It is a block diagram which shows the freezing apparatus concerning 1st Embodiment of this invention. It is a figure which shows the supply state of the cold water and cooling water of the freezing apparatus concerning 1st Embodiment. It is a figure which shows the refrigerating cycle of each refrigerator 20-1, 20-2 concerning 1st Embodiment. It is a figure which shows the refrigerating cycle of each refrigerator 200-1, 200-2 of the conventional freezing apparatus shown in FIG. It is a figure which shows the evaporation temperature with respect to the chilled water temperature of each refrigerator 20-1, 20-2 of the freezing apparatus concerning 1st Embodiment, and the condensation temperature with respect to a cooling water temperature. It is a figure which shows the evaporating temperature with respect to the cold water temperature of each refrigerator 200-1, 200-2 of the conventional freezing apparatus shown in FIG. 19, and the condensation temperature with respect to cooling water temperature. It is a figure which shows the supply state of the cold water and cooling water of the freezing apparatus concerning 2nd Embodiment. It is a figure which shows the refrigerating cycle of each freezer 20-1 and 20-2 of the freezing apparatus concerning 2nd Embodiment. It is a figure which shows the evaporation temperature with respect to the chilled water temperature of each refrigerator 20-1, 20-2 of the freezing apparatus concerning 2nd Embodiment, and the condensation temperature with respect to a cooling water temperature. It is a block diagram of the freezing apparatus concerning 3rd Embodiment of this invention. It is a figure which shows the supply state of the cold water and cooling water of the freezing apparatus concerning 3rd Embodiment. It is a block diagram of the modification of the freezing apparatus concerning 3rd Embodiment of this invention. It is a block diagram which shows an example of the conventional freezing apparatus. It is a figure which shows the supply state of the cold water and cooling water of the freezing apparatus shown in FIG.

Explanation of symbols

20 (20-1, 20-2) refrigerator 20A refrigerator 20B (20B-1, 20B-2) refrigerator 21 (21-1, 21-2) evaporator 23 (23-1, 23-2) compression Machine 25 (25-1, 25-2) Condenser 27 (27-1, 27-2) Expansion valve 28 (28-1, 28-2) Power recovery expander 281 Generator (power recovery machine)
29 (29-1, 29-2) Refrigerant piping M Electric motor 31 Economizer 31 'Economizer 37 Can body 39 Can body

Claims

At least an evaporator that removes heat from the fluid to be cooled to evaporate the refrigerant and exerts a refrigeration effect, a compressor that compresses the refrigerant vapor into high-pressure vapor, and a condensation that cools and condenses the high-pressure vapor with the cooling fluid Equipped with two refrigerators,
The fluid to be cooled are connected in series to the evaporator of said two refrigerator are cooled in a sequential refrigerant of the two evaporators evaporation heat,
The cooling fluid is connected in series with the condenser of the two refrigerators, cooling the refrigerant in the sequential two condensers,
The compressor of each of the two refrigerators is configured to be driven by the same electric motor, and a seal between the electric motor and the two compressors is a labyrinth seal,
The condenser of one of the two refrigerators and the evaporator of the other refrigerator are connected by a first pipe having an on-off valve, and the condenser of the other refrigerator and the evaporation of one refrigerator are connected. And a second pipe having an on / off valve, and a refrigerant bias eliminating means for eliminating the refrigerant bias between the two refrigerators by opening / closing control of the on / off valve of the first pipe and the on / off valve of the second pipe. refrigeration system, wherein a provided.
At least the evaporators of the two refrigerators are installed in the respective compartments that divide one can body, or the condensers of the two refrigerators are each compartment that divides one can body The refrigeration apparatus according to claim 1, wherein the refrigeration apparatus is installed in the refrigeration apparatus.
Wherein the the refrigerant pipe connecting the evaporator Each condenser two refrigerators, and characterized in that the power recovery expander for recovering energy of the flow of refrigerant to the evaporator from the condenser is provided The refrigeration apparatus according to claim 1 or 2.
The refrigeration apparatus according to claim 3, wherein the power recovery expander recovers power by driving a generator with energy of a refrigerant flow.