Refrigerating device

Abstract

To provide a refrigerating device.SOLUTION: A refrigerating device (100) includes a compressor (1), an oil separator (2) for separating a refrigerant and an oil from the compressor (1), a condenser (3a) for condensing the refrigerant separated by the oil separator (2), an oil cooler (7) for cooling the oil separated by the oil separator (2), and an air blower 9a for blowing air to the condenser (3a) and the oil cooler (7). The condenser (3a) and the oil cooler (7) are integrated into one air heat exchanger (20a). The oil cooler (7) is provided on the upper side of the condenser (3a) in the air heat exchanger (20a).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a refrigeration system including a condenser and an oil cooler. [Background technology]

[0002] There is a demand to change the refrigerants used in refrigeration equipment to ones with a low global warming potential. Such a change in refrigerant is expected to result in a decline in the performance of the refrigeration equipment due to the effects of the refrigerant's physical properties. When considering replacing existing refrigeration equipment, it is desirable for the new refrigeration equipment to have performance as close as possible to that of the existing equipment. Therefore, there is a demand for improving performance while minimizing the need for additional components (for example, speed increase using an inverter).

[0003] Conventionally, refrigeration oil in a refrigeration system has been cooled using the refrigerant in the refrigeration cycle, but using the refrigerant in the refrigeration cycle to cool the refrigeration oil results in a corresponding loss of refrigeration capacity of the refrigeration system.

[0004] In relation to oil cooling, International Publication No. 2016 / 170680 (Patent Document 1) and Japanese Patent Laid-Open No. 2011-89736 (Patent Document 2) are known.

[0005] Patent Document 1 discloses a refrigeration and air conditioning system including an oil separator disposed on the discharge side of the compressor and on the inlet side of the condenser, a hot gas bypass pipe that directs refrigerant flowing from the oil separator to an evaporator, a hot gas control valve disposed on the hot gas bypass pipe, an oil return pipe that returns lubricating oil stored in the oil separator to the compressor, an oil cooler disposed on the oil return pipe that cools refrigeration oil flowing through the oil return pipe, an oil supply bypass circuit that branches off from the oil return pipe upstream of the oil cooler and merges with the oil return pipe downstream of the oil cooler, and an oil supply bypass motor-operated valve disposed on the oil supply bypass circuit. Patent Document 1 does not specify the specific location of the oil cooler, but the oil cooler is depicted as being independently attached to the condenser.

[0006] Patent Document 2 discloses an air conditioner having a structure in which refrigeration oil contained in refrigerant gas discharged from a compressor is separated by an oil separator provided on the compressor discharge side and returned to the compressor suction side, in which the refrigeration oil separated in the oil separator is introduced into a part of an outdoor heat exchanger, cooled by outside air, and returned to the compressor suction side, and a heat exchanger used to cool the refrigeration oil is located below the suction side of the refrigerant heat exchanger. Patent Document 2 also discloses that because the refrigerant condenser is located above and the heat exchanger (oil cooler section) used to cool the refrigeration oil is located below, the temperature of the lower part of the heat exchanger acting as a refrigerant evaporator can be increased during heating, preventing water from freezing in the water receiving section below the heat exchanger during defrosting and allowing drain water to be smoothly discharged, improving the reliability of the air conditioner.

[0007] The prior arts of Patent Documents 1 and 2 use an air heat exchanger in the oil cooling circuit and adjust the oil temperature by providing a bypass circuit that does not pass through the oil cooler. However, in the prior art of Patent Document 1, the condenser of the air heat exchanger and the oil cooler are each dedicated and adjacent, and are cooled by a single fan. Thus, in the prior art of Patent Document 1, the heat exchangers for oil cooling and the condenser are arranged independently, which requires an additional independent air heat exchanger for the oil cooler compared to chillers that use refrigerant cooling. This tends to result in larger chillers. In the prior art of Patent Document 2, the oil cooling unit is arranged on the lower side. This is a configuration to prevent water from freezing in the water receiving section below the heat exchanger during defrosting during heating in an air conditioner. Therefore, in the chiller of Patent Document 2, it is necessary to provide space below the air heat exchanger for draining oil during maintenance, which tends to result in larger chillers. Furthermore, in the prior art of Patent Document 1 and Patent Document 2, no means are provided for filling the air heat exchanger with oil, which may result in the air heat exchanger not being filled with oil and the heat transfer area of ​​the air heat exchanger not being utilized to its full potential. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2016 / 170680 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-89736 Summary of the Invention [Problem to be solved by the invention]

[0009] The present disclosure has been made in consideration of the above-mentioned drawbacks in the conventional technology, and aims to provide a refrigeration device that enables oil to be discharged appropriately during oil change, and that is compact and has reduced costs. [Means for solving the problem]

[0010] In order to solve the above problems, the present disclosure provides a refrigeration system having the following features. The refrigeration system includes a compressor, an oil separator that separates refrigerant and oil from the compressor, a condenser that condenses the refrigerant separated in the oil separator, an oil cooler that cools the oil separated in the oil separator, and a blower that blows air to the condenser and the oil cooler. The condenser and oil cooler are integrated into a single air heat exchanger, and the oil cooler is provided above the condenser in the air heat exchanger. [Effects of the Invention]

[0011] The above-described configuration makes it possible to reliably and appropriately discharge oil when changing the oil, and also makes it possible to reduce the size of the refrigeration device and reduce costs. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing the overall configuration of a refrigerator according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating a configuration of a first air heat exchanger in a refrigerator according to an embodiment of the present disclosure. [Figure 3]FIG. 3 is a perspective view showing the configuration of a first air heat exchanger in a refrigerator according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a perspective view showing the configuration of a first air heat exchanger in a refrigerator according to another embodiment of the present disclosure. [Figure 5] FIG. 5 is a diagram showing the overall configuration of a refrigerator according to another embodiment of the present disclosure. [Figure 6] FIG. 6 is a diagram showing the overall configuration of a refrigerator according to still another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] One or more embodiments of the present disclosure will be described below with reference to the drawings, but the embodiments of the present disclosure are not limited to the specific embodiments described below. Note that the same reference numerals throughout the drawings indicate the same or corresponding parts.

[0014] The present disclosure is directed to a refrigeration system (100). The refrigeration system (100) according to an embodiment of the present disclosure includes a compressor (1), an oil separator (2) that separates refrigerant and oil from the compressor (1), a condenser (3a) that condenses the refrigerant separated in the oil separator (2), an oil cooler (7) that cools the oil separated in the oil separator, and a blower (9a) that blows air to the condenser (3a) and the oil cooler (7). In the refrigeration system (100), the condenser (3a) and the oil cooler (7) are integrated into a single air heat exchanger (20a). The oil cooler (7) is provided above the condenser (3a) in the air heat exchanger (20a).

[0015] The above-described configuration makes it possible to preferably discharge oil when changing oil, and also makes it possible to reduce the size of the refrigeration device and reduce costs.

[0016] More specifically, by integrating the condenser (3a) and the oil cooler (7) into a single air heat exchanger (20a), compared to a configuration in which the condenser and the oil cooler are each dedicated and adjacent and cooled by a single fan, an additional air heat exchanger for the oil cooler is unnecessary. This increases the design flexibility of the air heat exchanger and minimizes the area occupied by the air heat exchanger in the refrigeration system, thereby minimizing the size and cost of the refrigeration system. Furthermore, while oil is normally discharged by gravity during oil change, by locating the oil cooler (7) above the condenser (3a) in the air heat exchanger (20a), the oil in the oil cooler (7) can be drained using the space between the oil cooler (7) and the bottom of the refrigeration system. This eliminates the need for a separate space below the air heat exchanger to drain the oil, enabling the refrigeration system to be more compact.

[0017] In a preferred embodiment, the oil cooler (7) has a first oil inlet / outlet used during operation and a second oil inlet / outlet located below the first oil inlet, and the second oil inlet / outlet is connected to a drain port through which oil is discharged when the oil is discharged for an oil change. This makes it possible to fill the oil cooler in the air heat exchanger with oil while ensuring that the oil can be discharged, and to utilize as much of the heat transfer area of ​​the air heat exchanger as possible.

[0018] In a preferred embodiment, the refrigeration system (100) further includes a subcooler (5') that subcools the refrigerant by heat exchange with outside air downstream of the condenser (3a). In this case, the subcooler (5') is provided in an air heat exchanger (e.g., the air heat exchanger (20b) including the condenser (3b)) other than the air heat exchanger (20a) including the oil cooler (7). Oil is a liquid and has a larger heat capacity than the refrigerant. If the oil cooler and the subcooler are adjacent to each other in the same air heat exchanger, the heat of the oil cooler heats the subcooled oil, resulting in a decrease in the degree of subcooling (i.e., performance degradation). By providing the subcooler (5') in an air heat exchanger other than the air heat exchanger including the oil cooler (7), the influence of the oil cooler (7), into which high-temperature oil flows, on the subcooler (5') can be substantially eliminated.

[0019] In a preferred embodiment, the refrigeration system (100) further includes a subcooler (5') downstream of the condenser (3a) that subcools the refrigerant by heat exchange with outside air. When the condenser (3a), oil cooler (7), and subcooler (5') are provided in a single air heat exchanger, the subcooler (5') is provided away from the oil cooler (7) with the condenser (3a) in between. Since oil is a liquid and has a larger heat capacity than the refrigerant, when the condenser, subcooler, and oil cooler are provided in a single air heat exchanger, if the subcooler and the oil cooler are adjacent to each other, the heat of the oil cooling will heat the subcooling, resulting in a decrease in the degree of subcooling (i.e., performance degradation). By providing the subcooler (5') away from the oil cooler (7) with the condenser (3a) in between, the influence of the oil cooler (7), into which high-temperature oil flows, on the subcooler (5') can be reduced.

[0020] In a preferred embodiment, the first oil inlet / outlet (26) is located at a position higher than the lower end of the oil cooler (7) (e.g., dotted line in FIG. 2 ) in at least the air heat exchanger (20a), and more preferably, higher than the piping (25) (e.g., all piping) constituting the oil cooler (7) in the air heat exchanger (20a). The first oil inlet / outlet (26) serves as an inlet during operation. The second oil inlet / outlet (27) is located at a position lower than the lower end of the oil cooler (7) in at least the air heat exchanger (20a), and more preferably, lower than the piping (25) (e.g., all piping) constituting the oil cooler (7) in the air heat exchanger (20a). The second oil inlet / outlet (27) serves as an outlet during operation and is connected to an oil charging inlet when charging oil. The second oil inlet / outlet (27) is connected to an oil discharge outlet for discharging oil when discharging oil for an oil change. By arranging the oil inlet and outlet in this manner, oil can be reliably filled in the oil cooler (7) of the air heat exchanger (20a), making it possible to maximize the use of the heat transfer surface of the air heat exchanger (20a) and reliably discharge the oil. This configuration also alleviates restrictions on the placement of the oil separator (2) and the oil cooler (7), increasing the degree of freedom in the placement of the oil separator (2). This configuration also allows for the provision of only the first oil inlet and outlet (26) and the second oil inlet and outlet (27) to provide an oil inlet and oil outlet during operation, an oil filling inlet during filling, and an oil discharge outlet during discharge.

[0021] In a specific embodiment, the first oil inlet / outlet (27) is located at a position higher than the lower end of the oil cooler (7) in at least the air heat exchanger (20a), and more preferably, at a position higher than the piping (25) (e.g., all piping) constituting the oil cooler (7) in the air heat exchanger (20a). The first oil inlet / outlet (27) serves as an outlet during operation. The second oil inlet / outlet (26) is located at a position lower than the lower end of the oil cooler (7) in at least the air heat exchanger (20a), and more preferably, at a position lower than the piping (25) (e.g., all piping) constituting the oil cooler (7) in the air heat exchanger (20a). The second oil inlet / outlet (26) serves as an inlet during operation, connects to an oil charging inlet when charging oil, and connects to an oil discharge outlet when discharging oil for an oil change. In this case, the oil separator (2) is provided at a height overlapping with or higher than the oil cooler (7) of the air heat exchanger. Although arranging the oil inlet and outlet in this manner restricts the locations of the oil separator (2) and the oil cooler (7), it is possible to reliably fill the oil cooler (7) of the air heat exchanger (20a) with oil, thereby making maximum use of the heat transfer surface of the air heat exchanger (20a) and reliably discharging the oil. In this configuration, by providing only the first oil inlet and outlet (27) and the second oil inlet and outlet (26), it is possible to provide an oil inlet and oil outlet during operation, an oil filling inlet during filling, and an oil discharge outlet during discharge.

[0022] In a specific embodiment, the oil cooler (7) further includes, in addition to the first oil inlet / outlet (26) and the second oil inlet / outlet (28), a third oil inlet / outlet (27) located above the second oil inlet / outlet (28). The first oil inlet / outlet (26) is located at a higher position than the lower end of the oil cooler (7) in at least the air heat exchanger (20a), and more preferably, is located at a higher position than the piping (25) (e.g., all piping) constituting the oil cooler (7) in the air heat exchanger (20a). The first oil inlet / outlet (26) serves as an inlet during operation. The third oil inlet / outlet (27) is located at a higher position than the lower end of the oil cooler (7) in at least the air heat exchanger (20a), and more preferably, is located at a higher position than the piping (25) (e.g., all piping) constituting the oil cooler (7) in the air heat exchanger (20a). The third oil inlet / outlet (27) serves as an outlet during operation. The second oil inlet / outlet (28) is located at a position lower than the lower end of the oil cooler (7) in at least the air heat exchanger (20a), and more preferably lower than the piping (25) (all piping) constituting the oil cooler (7) in the air heat exchanger (20a). The second oil inlet / outlet (28) is connected to an oil outlet for discharging oil during an oil change. Either the second oil inlet / outlet (28) or the third oil inlet / outlet (27) is connected to an oil charging inlet for charging oil. By arranging the oil inlet / outlet in this manner, oil can be reliably filled in the oil cooler (7) of the air heat exchanger (20a), maximizing the use of the heat transfer surface of the air heat exchanger and ensuring oil discharge. Furthermore, although the third oil inlet / outlet (27) is provided in this configuration, the constraints on the position of the oil separator (2) and the oil cooler (7) of the air heat exchanger are relaxed, thereby increasing the degree of freedom in the placement of the oil separator (2).

[0023] In a preferred embodiment, the refrigeration system (100) includes a bypass circuit that returns oil from the oil separator (2) to the compressor (1) without passing through the oil cooler (7). The bypass circuit includes valve means (8a, 8b) that change the flow rate of oil to the bypass circuit. When the outside air temperature is low, an excessive drop in oil temperature can increase the viscosity of the oil, which can reduce the supply of oil to the compressor (1) or excessively cool the temperature inside the compressor (1), potentially causing a breakdown of the compressor (1). By returning a portion of the high-temperature oil discharged from the compressor (1) to the compressor (1) without cooling it, an excessive drop in oil temperature can be prevented. This prevents an increase in the viscosity of the oil, making it possible to avoid a reduction in the supply of oil or a breakdown of the compressor (1).

[0024] In certain embodiments, the valve means is one or more solenoid valves that open or close to vary the flow rate of oil into the bypass circuit, while in other certain embodiments, the valve means is a solenoid valve that opens or closes to vary the flow rate of oil into the bypass circuit.

[0025] In a preferred embodiment, the oil cooler (7) and the condenser (3a) are provided in parallel with the flow of air blown by the blower (9a). This configuration makes it possible to easily optimize the heat transfer areas of the oil cooler (7) and the condenser (3a) in the air heat exchanger (20a) depending on the expected operating conditions of the refrigeration system.

[0026] Hereinafter, a refrigeration device according to one or more embodiments of the present disclosure will be described in more detail with reference to FIGS.

[0027] FIG. 1 is a diagram showing the overall configuration of a refrigerator 100 according to an embodiment of the present disclosure. The refrigerator 100 shown in FIG. 1 is an outdoor-installed screw-type refrigerator with a two-stage compression system. Note that an outdoor-installed two-stage screw compression refrigerator is an example of a refrigeration device to which the configuration according to an embodiment of the present disclosure can be applied, and the configuration of the refrigerator is not limited thereto. The refrigerator 100 is also called a condensing unit.

[0028] First, a refrigerant circuit in a refrigerator 100 shown in Fig. 1 will be described below. In Fig. 1, the refrigerant circuit of the refrigerator 100 is indicated by solid lines, and the flow of refrigerant is indicated by solid arrows. As shown in Fig. 1, the refrigerator 100 includes a compressor 1 that draws in refrigerant gas discharged from an evaporator 12, compresses the refrigerant, and discharges the compressed refrigerant, an oil separator 2 that separates the refrigerant discharged from the compressor 1 from refrigeration oil (hereinafter simply referred to as oil), a condenser 3 that condenses the refrigerant separated in the oil separator 2 by heat exchange with air, and a receiver 4 into which the condensed refrigerant from the condenser 3 flows. In the embodiment shown in Fig. 1, two condensers 3 are provided, which are referred to as a first condenser 3a and a second condenser 3b. The refrigerant separated in the oil separator 2 is then branched and guided to the first condenser 3a and the second condenser 3b, where it is condensed and then merges with the receiver 4.

[0029] As shown in FIG. 1, the chiller 100 further includes a subcooler 5 that subcools the refrigerant from the receiver 4. The refrigerant subcooled by the subcooler 5 is depressurized by an expansion valve 13 and supplied to the evaporator 12. The subcooler 5 is provided with a subcooling expansion valve 6, and a portion of the refrigerant is depressurized by the subcooling expansion valve 6 and enters the subcooler 5, where it exchanges heat with the refrigerant from the receiver 4 to subcool the refrigerant from the receiver 4, and is then returned to the intermediate stage of the compressor 1.

[0030] In the evaporator 12, the refrigerant absorbs heat from the air, water, etc., evaporates, and the refrigerant gas is discharged from the evaporator 12 to the compressor 1. In the configuration shown in Fig. 1, the evaporator 12 and expansion valve 13 enclosed by the dotted line are typically parts outside the refrigeration unit 100 that are prepared by the user, and constitute a showcase, a freezer / refrigerator, a unit cooler, an ice maker, etc.

[0031] The compressor 1 shown in Fig. 1 is a screw-type two-stage compression compressor. However, the compressor 1 is not limited to a screw-type compression compressor, and may be a compression compressor other than the screw type (for example, a scroll type, a reciprocating type, a rotary type, or a turbo type), or may be a single-stage compressor instead of a two-stage compressor.

[0032] The refrigerant used in the refrigerator 100 is not particularly limited, but may be a single refrigerant such as R32, R134a, or R1234yf; a near-azeotropic refrigerant such as R410A or R404A; a non-azeotropic refrigerant mixture such as R448A, R449A, R463A, R466A, R407C, R407H, R454B, R454C, or R455A; or a mixture thereof. Using a refrigerant with a low GWP (Global Warming Potential) can reduce the impact on global warming caused by refrigerant leakage from the refrigerator. For example, the refrigerant R448A can be used, which has a global warming potential that is approximately 64% lower than that of the refrigerant R404A and approximately 33% lower than that of the refrigerant R410A.

[0033] In Fig. 1, the oil circuit of the chiller 100 is further indicated by dotted lines, and the direction of oil flow is indicated by dotted arrows. The chiller 100 includes an oil cooler 7 that cools the oil. The oil is discharged from the compressor 1 together with the refrigerant and separated from the refrigerant in the oil separator 2, and flows into the oil cooler 7 via piping. The oil cooler 7 cools the refrigerant that has flowed in by exchanging heat with air. After being cooled by the oil cooler 7, the oil is returned to the compressor 1 via piping.

[0034] Furthermore, the refrigeration machine 100 has an oil circuit that returns oil to the compressor 1 via the oil cooler 7, as well as a bypass circuit that returns the oil separated in the oil separator 2 to the compressor 1 without passing through the oil cooler 7. A portion of the oil discharged together with the refrigerant from the compressor 1 and separated in the oil separator 2 may be returned to the compressor 1 via the bypass circuit without being cooled by the oil cooler 7. Solenoid valves 8a and 8b are provided in the bypass circuit, and the flow rate of oil returned via the bypass circuit (bypass amount) is adjusted by controlling the opening and closing of the solenoid valves 8a and 8b. Alternatively, if solenoid valves whose opening degree is variably controlled are provided in the bypass circuit instead of the solenoid valves 8a and 8b whose opening and closing are controlled, the flow rate of oil returned via the bypass circuit (bypass amount) is adjusted by controlling the opening of the solenoid valves.

[0035] The chiller 100 is designed to operate within a predetermined ambient temperature range (e.g., −10°C to +40°C), but is also designed to provide sufficient oil cooling even at the upper limit of the operating temperature range (e.g., +40°C). On the other hand, when the ambient temperature is near the lower limit of the operating temperature range (e.g., −10°C), the oil may be overcooled, resulting in an excessive drop in oil temperature. Furthermore, when starting up from a stopped state in low ambient air, the oil may be fully cooled, resulting in an excessive drop in oil temperature. An excessive drop in oil temperature can increase the oil viscosity, reducing the oil supply to the compressor 1 or excessively cooling the temperature inside the compressor 1, leading to compressor 1 failure. The bypass circuit described above prevents an excessive drop in oil temperature by returning a portion of the high-temperature oil discharged from the compressor 1 to the compressor 1 without cooling it in the oil cooler 7.

[0036] As shown in Fig. 1, in the embodiment being described, the first condenser 3a and the oil cooler 7 are integrated to form a single air heat exchanger (hereinafter referred to as the first air heat exchanger) 20a. In contrast, the second condenser 3b independently forms a single air heat exchanger (hereinafter referred to as the second air heat exchanger) 20b. Fig. 1 also shows a preferred arrangement of the first condenser 3a and the oil cooler 7, and in the embodiment being described, the oil cooler 7 is provided above the first condenser 3a in the first air heat exchanger 20a.

[0037] The chiller 100 includes a first fan 9a for blowing air to the first air heat exchanger 20a (the first condenser 3a and the oil cooler 7) and a second fan 9b for blowing air to the second air heat exchanger 20b (the second condenser 3b). The first fan 9a blows air drawn in from the outside toward the first air heat exchanger 20a, or draws air from the outside through the first air heat exchanger 20a, and then blows the air to the first condenser 3a and the oil cooler 7, which are provided in parallel with the air flow. The same applies to the second fan 9b. In FIG. 1, the fans 9a and 9b are depicted as being arranged in a top-flow configuration.

[0038] 1, the chiller 100 further includes various sensors 14-16 and a control device 17. More specifically, the various sensors 14-16 include an oil temperature sensor 14 provided after the bypass circuit and the pipe from the oil cooler 7 join together and before the oil is returned to the compressor 1, a discharge pressure sensor 15 provided in the oil separator 2, and an outside air temperature sensor 16 provided in the second air heat exchanger 20b (condenser 3b). The control device 17 is connected to actuators such as the blowers 9a, 9b and the solenoid valves 8a, 8b, and sensors such as the oil temperature sensor 14, the discharge pressure sensor 15, and the outside air temperature sensor 16.

[0039] The control device 17 controls the blowers 9a, 9b based on signals from the discharge pressure sensor 15 and the outside air temperature sensor 16, and controls the amount of air sent to the first air heat exchanger 20a (first condenser 3a and oil cooler 7) and the second air heat exchanger 20b (second condenser 3b). The control device 17 also controls the opening and closing of the solenoid valves 8a, 8b in the bypass circuit based on the temperature of the oil returned to the compressor 1 detected by the oil temperature sensor 14, to adjust the bypass amount and return oil to the compressor 1 at an appropriate oil temperature.

[0040] Hereinafter, a more specific configuration around the oil cooler 7 will be described with reference to FIGS.

[0041] Fig. 2 is a diagram illustrating the arrangement of the first condenser 3a and the oil cooler 7 in the first air heat exchanger 20a in the chiller 100 according to the embodiment of the present disclosure. Fig. 3 is a perspective view illustrating the configuration of the first air heat exchanger 20a in the chiller 100 according to the embodiment of the present disclosure. Note that the structure illustrated in Figs. 2 and 3 is a simplified representation of the structure of the first air heat exchanger 20a. In other words, the actual structure of the first air heat exchanger 20a is typically more complex (having a larger number of columns and pipes) than the structure illustrated in Figs. 2 and 3.

[0042] As shown in Figures 2 and 3, the first condenser 3a and the oil cooler 7 are arranged in parallel with respect to the air flow and integrally constitute a first air heat exchanger 20a. The first air heat exchanger 20a includes a plurality of fins 29 and pipes 21 and 25 that penetrate the plurality of fins 29. In Figure 2, the area indicated by gray hatching corresponds to the oil cooler 7 in the upper row, and the area indicated by white corresponds to the first condenser 3a in the lower row. The pipe 21 constitutes the first condenser 3a, and refrigerant flows through it. The pipe 25 constitutes the oil cooler 7, and oil flows through it. The boundary between the oil cooler 7 and the first condenser 3a is indicated by a dotted line.

[0043] The first condenser 3a is connected to a refrigerant inlet 22 and a refrigerant outlet 23. The first condenser 3a includes a pipe 21 that penetrates fins 29 and travels back and forth in a direction perpendicular to the plane of the drawing, and the pipe 21 is connected to the refrigerant inlet 22 via a header 22a and to the refrigerant outlet 23 via a header 23a. The refrigerant inlet 22 is connected to the oil separator 2, and the refrigerant outlet 23 is connected to the receiver 4.

[0044] The oil cooler 7 is connected to an oil inlet 26 and an oil outlet 27. The oil cooler 7 includes a pipe 25 that penetrates fins 29 and travels back and forth in a direction perpendicular to the plane of the drawing, and the pipe 25 is connected to the oil inlet 26 via a header 26a and to the oil outlet 27 via a header 27a. The oil inlet 26 is connected to the oil separator 2, and the oil outlet 27 is connected to the compressor 1.

[0045] 2 and 3, by adopting a configuration in which the first condenser 3a and the oil cooler 7 are integrated into one air heat exchanger 20a, compared to a configuration in which the condenser and the oil cooler are each dedicated and adjacent and cooled by one fan, it is not necessary to add an air heat exchanger for an independent oil cooler, which increases the design freedom of the air heat exchanger 20a and minimizes the area of ​​the chiller 100 occupied by the air heat exchanger 20a. As a result, the chiller 100 can be made smaller, and costs can also be reduced.

[0046] Furthermore, as shown in FIGS. 2 and 3 , the oil cooler 7 and the condenser 3a are integrated into a single air heat exchanger 20a so as to be arranged in parallel with the air flow blown by the blower 9a. This allows the ratio of the heat transfer areas of the oil cooler 7 and the condenser 3a in the air heat exchanger 20a to be designed according to the expected operating conditions of the chiller 100, thereby optimizing the heat transfer area of ​​each, thereby increasing the design flexibility of the air heat exchanger. For example, if the oil coolers are arranged in series with the air flow rather than in parallel with the air flow (i.e., if the condenser and oil cooler are arranged in rows), optimizing the heat transfer area becomes difficult. Furthermore, if the oil cooler is arranged in series with the air flow, performance is reduced because either the condenser or the oil cooler cannot directly come into contact with the outside air. In particular, if the oil cooler is located on the front side exposed to the outside air, the condenser cannot condense sufficiently due to the large heat capacity of the oil.

[0047] When the chiller 100 is in operation, the refrigerant and refrigeration oil flow in the directions indicated by the arrows. To explain the flow of oil, the oil enters the oil cooler 7 from the oil separator 2 via the header 26a and the oil inlet 26, flows through the pipe 25 while exchanging heat with the air in the oil cooler 7, exits the oil cooler 7 via the header 27a and the oil outlet 27, and is returned to the compressor 1.

[0048] The refrigeration oil is sealed in the oil cooler 7 during the manufacturing process of the refrigeration machine 100 or during the on-site installation process of the refrigeration machine 100. Furthermore, during maintenance work on the refrigeration machine 100, old refrigeration oil is discharged from the oil cooler 7, and new refrigeration oil is sealed in the oil cooler 7.

[0049] In the oil system shown in FIG. 1, an oil inlet / outlet port 10 is provided in the piping leading from the oil cooler 7 to the compressor 1 after merging with the bypass circuit. To inject oil, a vacuum is created inside the equipment and oil is drawn into the equipment from the oil outlet 27 side (oil inlet / outlet port 10) at the bottom of the air heat exchanger 20a. When the oil cooler 7 is filled to the top, the drawn-up oil flows down from the oil inlet 26 to the oil separator 2. Therefore, oil filling can be confirmed by confirming that the oil has accumulated to a predetermined position in the oil separator 2. In addition, oil is discharged by gravity from the oil inlet 27 side (oil inlet / outlet port 10) inside the oil cooler 7. Oil is discharged from the oil separator 2 to the inlet of the oil cooler 7 through the oil outlet 11.

[0050] In order to make maximum use of the heat transfer area of ​​the oil cooler 7, it is necessary to fill the oil evenly inside the oil cooler 7. In the embodiment to be described, the refrigerator 100 has the following configuration so that the oil is filled evenly inside the oil cooler 7.

[0051] That is, in the oil cooler 7, the oil inlet 26 is located at the upper part (above half of the air heat exchanger 20a (above the condenser 3a)), preferably above all of the piping 25 that constitute the oil cooler 7. The oil outlet 27 of the oil cooler 7 is located at the lower part (below half of the air heat exchanger 20a (below the oil cooler 7)), preferably below all of the piping 25 that constitute the oil cooler 7. The oil outlet 27 (connected to the oil charging / discharging port 10) is used for oil discharge during oil changes and for oil charging during initial and subsequent oil changes. Because the oil outlet 27 is located at the lower part, more preferably below all of the piping 25 that constitute the oil cooler 7, oil can be reliably drained from the air heat exchanger. With this configuration, when charging oil, it is possible to reliably charge the air heat exchanger with oil by confirming that the oil has accumulated up to a predetermined position in the oil separator 2.

[0052] In the configuration of the present disclosure, the oil cooler 7 is provided above the first condenser 3a in the air heat exchanger 20a. When changing oil, oil is discharged by gravity, but by providing the oil cooler 7 above the first condenser 3a in the air heat exchanger 20a, the oil in the oil cooler 7 can be drained using the space S between the oil cooler 7 and the bottom surface 30 of the refrigerator. This eliminates the need to secure a separate space below the air heat exchanger for draining oil, making it possible to downsize the refrigerator.

[0053] Furthermore, if oil is sealed in the oil cooler 7 so that it enters from above and leaves from below, and the oil cooler 7 is positioned above the oil separator 2, the oil will accumulate in the oil separator 2. On the other hand, by sealing the oil in the oil cooler 7 so that it enters from below and leaves from above, as in the embodiment described above, it is possible to alleviate restrictions on the placement of the oil cooler 7 and the oil separator 2, and therefore the refrigerator 100 can be made more compact.

[0054] Other embodiments of other arrangements of the oil inlet and outlet will be described below.

[0055] In another embodiment, the vertical relationship between the oil inlet 26 and the oil outlet 27 may be reversed. That is, in the oil cooler 7, the oil inlet 26 is located in the lower part (below half of the air heat exchanger 20a (below the oil cooler 7)), preferably below all of the piping 25 that constitute the oil cooler 7. The oil outlet 27 is located in the upper part (above half of the air heat exchanger 20a (above the first condenser 3a)), preferably above all of the piping 25 that constitute the oil cooler 7. The oil system shown in FIG. 1 is provided with an oil discharge port 11 in the piping leading from the bottom of the oil separator 2 to the oil cooler 7. The oil inlet 26 (connected to the oil discharge / oil seal inlet 11) is used for oil discharge during oil changes and for oil seal during initial and initial oil changes, and the oil is discharged from the oil outlet 27 (oil discharge port 10) during oil changes.

[0056] However, when such a structure is adopted, the oil separator 2 needs to be provided above the air heat exchanger 20a (at a height overlapping with the oil cooler 7 or higher). If the oil cooler 7 is configured so that oil enters from above and exits from below when sealed, there is no problem as long as the oil separator 2 is located above the oil cooler 7, but if the oil cooler 7 is located above the oil separator 2, the oil will accumulate in the oil separator 2. By arranging the oil inlet and outlet in this way, although there are restrictions on the locations where the oil separator 2 and the oil cooler 7 can be installed, it is possible to reliably fill the oil cooler 7 of the air heat exchanger 20a with oil, making maximum use of the heat transfer surface of the air heat exchanger 20a, and also to reliably discharge the oil.

[0057] 4 is a perspective view showing the configuration of a first air heat exchanger 20a in a refrigerator according to still another embodiment of the present disclosure. In this embodiment, the refrigerator 100 has the following configuration so that oil can be evenly sealed inside the oil cooler 7.

[0058] That is, in the embodiment to be described, the oil cooler 7 has an oil inlet 26 arranged in the upper part (above half of the air heat exchanger 20a (above the condenser 3a)), preferably arranged above all of the pipes 25 that constitute the oil cooler 7. The oil outlet 27 is arranged in the upper part (above half of the air heat exchanger 20a (above the condenser 3a)), preferably arranged above all of the pipes 25 that constitute the oil cooler 7. Furthermore, the oil cooler 7 is separately provided with an oil discharge port 28 below the oil outlet 27. The oil cooler 7 has the oil discharge port 28 arranged in the lower part (below half of the air heat exchanger 20a (below the oil cooler 7)), preferably arranged below all of the pipes 25 that constitute the oil cooler 7. The oil cooler 7 is configured so that oil is discharged from the oil discharge port 28 when changing oil, and oil is charged from the oil outlet 27 side (oil charging / discharging port 10) when changing oil for the first time and when changing oil. If the oil inlet 26 is located higher than the oil outlet 27, oil charging for the first time and when changing the oil may be performed through the oil discharge port 28. Oil is discharged from the oil outlet 27 side (oil charging / discharge port 10) from the outlet of the oil cooler 7 to the compressor 1. In this configuration, a separate oil discharge port 28 is provided, but the oil separator 2 does not need to be located higher than the oil cooler 7 of the air heat exchanger 20a, which increases the degree of freedom in locating the oil separator 2.

[0059] Fig. 5 is a diagram showing the overall configuration of a refrigerator 100 according to another embodiment of the present disclosure. The other embodiment shown in Fig. 5 has a similar configuration to the embodiment shown in Fig. 1, and therefore the following description will focus on the differences.

[0060] As shown in FIG. 5, the chiller 100 includes a compressor 1, an oil separator 2, condensers 3a and 3b, a liquid receiver 4, a first subcooler 5', and a second subcooler 5. The first subcooler 5' receives the refrigerant from the liquid receiver 4 and subcools the refrigerant through heat exchange with outside air. The second subcooler 5 is provided with a subcooling expansion valve 6, and a portion of the refrigerant is decompressed by the subcooling expansion valve 6 and enters the second subcooler 5, where it exchanges heat with the refrigerant from the first subcooler 5' and subcools the refrigerant. This portion of the refrigerant is returned to an intermediate stage of the compressor 1. The refrigerant subcooled by the second subcooler is decompressed by an expansion valve 13 and supplied to the evaporator 12.

[0061] The oil circuit shown in FIG. 5 has the same configuration as that shown in FIG. 1. As shown in FIG. 5, in the embodiment being described, the first condenser 3a and the oil cooler 7 are integrated to form the first air heat exchanger 20a. In the embodiment shown in FIG. 5, the second condenser 3b and the first subcooler 5′ are integrated to form the second air heat exchanger 20b. The first blower 9a blows air to the first air heat exchanger 20a (the first condenser 3a and the oil cooler 7). The second blower 9b blows air to the second air heat exchanger 20b (the second condenser 3b and the first subcooler 5′).

[0062] The control device 17 controls the blowers 9a, 9b based on signals from the discharge pressure sensor 15 and the outside air temperature sensor 16, and controls the amount of air sent to the first air heat exchanger 20a (first condenser 3a and oil cooler 7) and the second air heat exchanger 20b (second condenser 3b and first supercooler 5').

[0063] In the embodiment shown in FIG. 5, the first subcooler 5' is provided in an air heat exchanger 20b separate from the air heat exchanger 20a in which the oil cooler 7 is provided. Oil is a liquid and has a larger heat capacity than the refrigerant. If the oil cooler and the subcooler are adjacent to each other in the same air heat exchanger, the heat from the oil cooler will heat the subcooler, reducing the degree of subcooling and degrading refrigeration performance. By arranging the subcooler 5' in the second air heat exchanger 20b separate from the first air heat exchanger 20a in which the oil cooler 7 is provided, the impact of the oil cooler 7, into which high-temperature oil flows, on the subcooler 5' can be reduced.

[0064] The first supercooler 5' has a different temperature range from the condenser 3 and the oil cooler 7. On the other hand, the condenser 3 and the oil cooler 7 have the same temperature range. Therefore, at first glance, combining the condenser 3 and the first supercooler 5' appears to be no different from combining the oil cooler 7 and the first supercooler 5'. However, the condenser 3 and the oil cooler 7 have different heat capacities, and even though they are in the same temperature range, the influence of the condenser 3 on the supercooler 5' is different from the influence of the oil cooler 7 on the supercooler 5', with the former being smaller.

[0065] Fig. 6 is a diagram showing the overall configuration of a refrigerator 100 according to yet another embodiment of the present disclosure. The yet another embodiment shown in Fig. 6 has a configuration similar to the embodiments shown in Fig. 1 and Fig. 5, and therefore the following description will focus on the differences.

[0066] As shown in FIG. 6, the chiller 100 includes a compressor 1, an oil separator 2, condensers 3a and 3b, a liquid receiver 4, a first supercooler 5', and a second supercooler 5. The first supercooler 5' receives the refrigerant from the liquid receiver 4 and supercools the refrigerant through heat exchange with outside air. The second supercooler 5 further supercools the refrigerant from the first supercooler 5'. The supercooler 5 is provided with a subcooling expansion valve 6. The refrigerant supercooled by the supercooler 5 is depressurized by an expansion valve 13 and supplied to the evaporator 12.

[0067] The control device 17 controls the blowers 9a, 9b based on signals from the discharge pressure sensor 15 and the outside air temperature sensor 16, and controls the amount of air sent to the first air heat exchanger 20a (first condenser 3a, oil cooler 7 and subcooler 5') and the second air heat exchanger 20b (second condenser 3b).

[0068] In the embodiment shown in FIG. 6, the condenser 3a, oil cooler 7, and subcooler 5' are provided in a single air heat exchanger 20a. In this case, as shown in FIG. 6, the subcooler 5' is desirably provided away from the oil cooler 7 with the condenser 3a in between. Oil is a liquid and has a larger heat capacity than the refrigerant. When the condenser, subcooler, and oil cooler are provided in a single air heat exchanger, if the subcooler and the oil cooler are adjacent to each other, the heat from the oil cooler will heat the subcooler, reducing the degree of subcooling and degrading refrigeration performance. By providing the subcooler 5' away from the oil cooler 7 with the condenser 3a in between, the impact of the oil cooler 7, into which high-temperature oil flows, on the subcooler 5' can be reduced.

[0069] As described above, according to the embodiments of the present disclosure, a refrigerator is provided that can reliably and appropriately discharge oil during oil change, and that can be made smaller and less expensive.

[0070] It should be noted that the embodiments of the present invention are not limited to the above-described embodiments and may include various modifications. For example, the above-described embodiments have been described in detail for ease of understanding, and are not necessarily limited to those including all of the described features. Furthermore, some of the features of one embodiment may be replaced with features of another embodiment, or features of one embodiment may be added to features of another embodiment. Furthermore, some of the features of each embodiment may be added to, deleted from, or replaced with other features. [Explanation of symbols]

[0071] 100...refrigerating unit, 1...compressor, 2...oil separator, 3a, 3b...condenser, 4...receiver, 5, 5'...subcooler, 6...expansion valve, 7...oil cooler, 8a, 8b...solenoid valve, 9a, 9b...blower, 10...oil filling / discharge port, 11...oil discharge port, 12...evaporator, 13...expansion valve, 14...oil temperature sensor, 15...discharge pressure sensor, 16...outside air temperature sensor, 17...control device, 20a, 20b...air heat exchanger, 21, 25...piping, 22...refrigerant inlet, 23...refrigerant outlet, 26...oil inlet, 27...oil outlet, 28...oil discharge port, 29...fin, 22a, 23a, 26a, 27a...header, 30...bottom of refrigerator

Claims

1. 1. A refrigeration device comprising: A compressor; an oil separator for separating refrigerant and oil from the compressor; a condenser for condensing the refrigerant separated by the oil separator; an oil cooler that cools the oil separated by the oil separator; a blower for blowing air to the condenser and the oil cooler; wherein the condenser and the oil cooler are integrated into one air heat exchanger, and the oil cooler is provided in an upper stage of the condenser in the air heat exchanger.

2. 2. The refrigeration apparatus according to claim 1, wherein the oil cooler comprises a first oil inlet / outlet used during operation and a second oil inlet / outlet located below the first oil inlet / outlet, and the second oil inlet / outlet is connected to a discharge port through which oil is discharged when the oil is discharged for oil change.

3. The refrigeration device is A subcooler that subcools the refrigerant by heat exchange with outside air at the rear of the condenser Furthermore, 2. The refrigeration apparatus according to claim 1, wherein the subcooler is provided in an air heat exchanger different from the one air heat exchanger in which the oil cooler is provided.

4. The refrigeration device is A subcooler that subcools the refrigerant by heat exchange with outside air at the rear of the condenser Furthermore, The refrigeration apparatus according to claim 1 , wherein the subcooler is provided in the one air heat exchanger, separated from the oil cooler with the condenser interposed therebetween.

5. the first oil inlet / outlet is located in the air heat exchanger at a position higher than the piping constituting the oil cooler, and serves as an inlet during operation; 3. The refrigeration apparatus according to claim 2, wherein the second oil inlet / outlet is located in a position lower than the piping constituting the oil cooler in the air heat exchanger, serves as an outlet during operation, and is connected to an oil charging inlet when charging oil.

6. the first oil inlet / outlet is located in the air heat exchanger at a position higher than the piping constituting the oil cooler, and serves as an outlet during operation; The second oil inlet / outlet is located in a position lower than the piping constituting the oil cooler in the air heat exchanger, serves as an inlet during operation, and is connected to an inlet when oil is charged.

3. The refrigeration apparatus according to claim 2, wherein the oil separator is provided at a height overlapping with the oil cooler of the air heat exchanger or at a higher position.

7. the oil cooler further includes a third oil inlet / outlet located above the second oil inlet / outlet; the first oil inlet / outlet is located in the air heat exchanger at a position higher than the piping constituting the oil cooler, and serves as an inlet during operation; the third oil inlet / outlet is located in the air heat exchanger at a position higher than the piping constituting the oil cooler, and serves as an outlet during operation; the second oil inlet / outlet is located at a lower position in the air heat exchanger than a pipe constituting the oil cooler, The refrigeration device according to claim 2 , wherein either the second oil inlet / outlet or the third oil inlet / outlet is connected to an oil charging inlet when charging oil.

8. 2. The refrigeration system according to claim 1, further comprising a bypass circuit for returning oil from said oil separator to said compressor without passing through said oil cooler, and a valve means for varying the flow rate of oil to said bypass circuit.

9. 9. The refrigeration apparatus according to claim 8, wherein the valve means is one or more electromagnetic valves that change the flow rate by opening or closing, or a solenoid valve that changes the flow rate by changing its opening degree.

10. The refrigeration apparatus according to claim 1 , wherein the oil cooler and the condenser are provided in parallel with respect to a flow of air blown by the blower.

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