JP6497581B2 - Refrigerator unit - Google Patents

Description

  The present invention relates to a refrigerator unit.

Conventionally, a refrigeration apparatus has a refrigeration cycle composed of a compression means, a gas cooler, a throttle means, etc., and the refrigerant compressed by the compression means dissipates heat in the gas cooler and is depressurized by the throttle means, and then the refrigerant is discharged by the evaporator. The surrounding air was cooled by evaporation of the refrigerant at this time. In recent years, chlorofluorocarbon refrigerants cannot be used in this type of refrigeration system due to natural environmental problems. For this reason, the thing using the carbon dioxide which is a natural refrigerant | coolant is developed as a substitute of a fluorocarbon refrigerant | coolant. The carbon dioxide refrigerant is a refrigerant having a high and low pressure difference, and has a low critical pressure. It is known that the high pressure side of the refrigerant cycle is brought into a supercritical state by compression (see, for example, Patent Document 1).
Moreover, in the heat pump device constituting the water heater, a carbon dioxide refrigerant capable of obtaining an excellent heating action in the gas cooler has been used. In that case, the refrigerant discharged from the gas cooler is expanded in two stages, There has also been developed an apparatus in which a gas-liquid separator is interposed between expansion devices to enable gas injection into a compressor (see, for example, Patent Document 2).
On the other hand, for example, in an refrigeration system that uses an endothermic action in an evaporator installed in a showcase or the like to cool the interior, the refrigerant temperature at the outlet of the gas cooler is high due to factors such as high outside air temperature (heat source temperature on the gas cooler side). Under higher conditions, the specific enthalpy at the inlet of the evaporator increases, which causes a problem that the refrigerating capacity is remarkably reduced. In such a case, if the discharge pressure (high-pressure side pressure) of the compression means is increased in order to ensure the refrigeration capacity, the compression power increases and the coefficient of performance decreases.
Therefore, the refrigerant cooled by the gas cooler is divided into two refrigerant streams, one of the divided refrigerant streams is squeezed by the auxiliary throttle means, and then flows into one passage of the split heat exchanger, and the other refrigerant stream is split. A so-called split-cycle refrigeration apparatus has been proposed in which heat is exchanged by flowing through the other flow path of the heat exchanger and then flows into the evaporator via the main throttle means. According to such a refrigeration apparatus, the second refrigerant flow can be cooled by the first refrigerant flow expanded under reduced pressure, and the refrigeration capacity can be improved by reducing the specific enthalpy at the inlet of the evaporator. (For example, refer to Patent Document 3).

Japanese Patent Publication No. 7-18602 JP 2007-178042 A JP 2011-133207 A

In such a conventional technique, when the oil in the oil separator becomes high temperature, the oil viscosity is lowered, and the sliding portion of the compressor may be worn.
This invention is made | formed in view of the situation mentioned above, and aims at providing the refrigerator unit which can cool the oil temperature in an oil separator.

To achieve the above object, the present invention includes a machine room disposed compressor, an outdoor heat exchanger, the refrigeration unit comprising a heat exchange chamber arranged blower, the outdoor heat exchanger the heat The outdoor heat exchanger is arranged from the side surface to the back surface of the exchange chamber, and extends to the rear of the machine room in a front view, and partitions the machine room and the heat exchange chamber at the center of the unit body. A partition plate is provided over the entire vertical direction, the partition plate is bent obliquely from the rear in a top view, a rear end portion of the partition plate is fixed to an end portion of the outdoor heat exchanger, and the blower is An oil separator disposed on the front surface of the unit main body and provided in a discharge portion of the compressor is between the outdoor heat exchanger and the blower, and is in a position overlapping the blower in a front view, and , The above Ri plate was positioned adjacent to, that is characterized.

  Further, the present invention is characterized in that a carbon dioxide refrigerant is used as a refrigerant for the refrigeration cycle.

  According to this invention, since the oil separator provided in the discharge part of the compressor was arrange | positioned in the ventilation path of an air blower, the refrigerator unit which can cool the oil temperature in an oil separator by ventilation of an air blower can be provided.

It is a circuit diagram of the refrigerating cycle in the refrigerating device concerning the embodiment of the present invention. FIG. 2 is a PH diagram of a combined cycle of a two-stage expansion cycle and a split cycle executed by the refrigeration cycle control device of FIG. 1. FIG. 2 is a PH diagram of a two-stage expansion cycle executed by the refrigeration cycle control device of FIG. 1. FIG. 2 is a PH diagram of a combined cycle of split cycles executed by the control device for the refrigeration cycle in FIG. 1. It is a perspective view which shows the outline of the state which removed the front cover of the refrigerator unit. It is a front view which shows the outline of the state which removed the front cover of the refrigerator unit. It is a disassembled perspective view of a unit main body.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a refrigerant circuit diagram of a refrigeration apparatus R according to an embodiment to which the present invention is applied. The refrigeration apparatus R in this embodiment is a show of a refrigerator unit 3 installed in a machine room or the like of a store such as a supermarket, and one or a plurality of units (only one is shown in the drawing) installed in the store sales area. The refrigerator unit 3 and the showcase 4 are connected by a refrigerant pipe (liquid pipe) 8 and a refrigerant pipe 9 via a unit outlet 6 and a unit inlet 7 so that a predetermined refrigerant circuit 1 is provided. It is composed.

  The refrigerant circuit 1 uses, as a refrigerant, carbon dioxide (R744) in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure (supercritical). This carbon dioxide refrigerant is a natural refrigerant that is friendly to the global environment and takes into consideration flammability and toxicity. As the lubricating oil, existing oils such as mineral oil (mineral oil), alkylbenzene oil, ether oil, ester oil, and PAG (polyalkyl glycol) are used.

  The refrigerator unit 3 includes a compressor 11 as compression means. In this embodiment, the compressor 11 is an internal intermediate pressure type two-stage compression rotary compressor, and includes an airtight container 12, an electric element 13 as a drive element disposed and housed in the upper part of the internal space of the airtight container 12, and the A first (low stage side) rotary compression element (first compression element) 14 and a second (high stage side) rotary compression element (first stage) disposed below the electric element 13 and driven by the rotating shaft thereof. 2 compression elements) 16 and a rotary compression mechanism.

  The first rotary compression element 14 of the compressor 11 compresses the low-pressure refrigerant sucked into the compressor 11 from the low-pressure side of the refrigerant circuit 1 through the refrigerant pipe 9 and raises it to an intermediate pressure for discharge. The rotary compression element 16 further sucks in the intermediate pressure refrigerant compressed and discharged by the first rotary compression element 14, compresses it to a high pressure, and discharges it to the high pressure side of the refrigerant circuit 1. The compressor 11 is a variable frequency compressor, and the rotational frequency of the first rotary compression element 14 and the second rotary compression element 16 can be controlled by changing the operating frequency of the electric element 13.

  On the side surface of the sealed container 12 of the compressor 11, a low-stage suction port 17 communicating with the first rotary compression element 14, a low-stage discharge port 18 communicating with the inside of the sealed container 12, and a second rotational compression A high-stage suction port 19 and a high-stage discharge port 21 communicating with the element 16 are formed. One end of the refrigerant introduction pipe 22 is connected to the lower stage side suction port 17 of the compressor 11, and the other end is connected to the refrigerant pipe 9 at the unit inlet 7.

  The low-pressure refrigerant gas (LP: about 2.6 MPa in the normal operation state) sucked into the low-pressure portion of the first rotary compression element 14 from the low-stage suction port 17 is intermediate pressure by the first rotary compression element 14. The pressure is increased to (MP: about 5.5 MPa in a normal operation state) and discharged into the sealed container 12. Thereby, the inside of the airtight container 12 becomes an intermediate pressure (MP).

  One end of the intermediate pressure discharge pipe 23 is connected to the low-stage discharge port 18 of the compressor 11 from which the intermediate pressure refrigerant gas in the sealed container 12 is discharged, and the other end is connected to the inlet of the intercooler 24. ing. The intercooler 24 air-cools the intermediate pressure refrigerant discharged from the first rotary compression element 14, and one end of an intermediate pressure suction pipe 26 is connected to the outlet of the intercooler 24. The other end of the pipe 26 is connected to the higher stage suction port 19 of the compressor 11.

  The intermediate pressure (MP) refrigerant gas sucked into the second rotary compression element 16 from the high-stage side suction port 19 is compressed in the second stage by the second rotary compression element 16 to generate a high temperature and high pressure (HP). : Supercritical pressure of about 9 MPa in a normal operation state).

  One end of a high-pressure discharge pipe 27 is connected to the high-stage discharge port 21 provided on the high-pressure chamber side of the second rotary compression element 16 of the compressor 11, and the other end is a gas cooler (heat radiator) 28. Connected to the entrance. An oil separator 20 is provided in the high-pressure discharge pipe 27. The oil separator 20 separates the oil in the refrigerant discharged from the compressor 11 and returns it to the sealed container 12 of the compressor 11 through the oil passage 25A and the electric valve 25B. Reference numeral 55 denotes a float switch for detecting the oil level in the compressor 11.

  The gas cooler 28 cools the high-pressure discharged refrigerant discharged from the compressor 11, and a blower 31 for air-cooling the gas cooler 28 is disposed in the vicinity of the gas cooler 28.

  One end of a gas cooler outlet pipe 32 is connected to the outlet of the gas cooler 28, and the other end of the gas cooler outlet pipe 32 is connected to an inlet of an electric expansion valve 33 as a pressure adjusting throttle means. The electric expansion valve 33 is used to squeeze and expand the refrigerant discharged from the gas cooler 28 and to adjust the high-pressure side pressure of the refrigerant circuit 1 upstream from the electric expansion valve 33, and the outlet thereof is a tank inlet pipe 34. It is connected to the upper part of the tank 36 via.

  The tank 36 is a volume body having a predetermined volume space inside, and one end of a tank outlet pipe 37 is connected to the lower part of the tank 36, and the other end of the tank outlet pipe 37 is connected to the refrigerant pipe 8 at the unit outlet 6. Has been.

  On the other hand, the showcase 4 installed in the store is connected to the refrigerant pipes 8 and 9. The showcase 4 is provided with an electric expansion valve 39 and an evaporator 41 as main throttle means, which are sequentially connected between the refrigerant pipe 8 and the refrigerant pipe 9 (the electric expansion valve 39 is connected to the refrigerant pipe 8). Side, the evaporator 41 is the refrigerant pipe 9 side). The evaporator 41 is provided with a cool air circulation blower (not shown) that blows air to the evaporator 41. The refrigerant pipe 9 is connected to the low-stage suction port 17 that communicates with the first rotary compression element 14 of the compressor 11 via the refrigerant introduction pipe 22 as described above.

  On the other hand, one end of a gas pipe 42 is connected to the upper portion of the tank 36, and the other end of the gas pipe 42 is connected to an inlet of an electric expansion valve 43 as a first auxiliary circuit throttle means. The gas pipe 42 causes the gas refrigerant to flow out from the upper portion of the tank 36 and to flow into the electric expansion valve 43. One end of the intermediate pressure return pipe 44 is connected to the outlet of the electric expansion valve 43, and the other end is connected to the middle pressure suction pipe 26 as an example of an intermediate pressure region connected to the intermediate pressure portion of the compressor 11. Yes. A first flow path 29 A of the split heat exchanger 29 is interposed in the intermediate pressure return pipe 44.

  One end of a liquid pipe 46 is connected to the lower part of the tank 36, and the other end of the liquid pipe 46 is connected to an intermediate pressure return pipe 44 on the downstream side of the electric expansion valve 43. Further, an electric expansion valve 47 as a second auxiliary circuit throttle means is interposed in the liquid pipe 46. The electric expansion valve 43 (first auxiliary circuit throttle means) and the electric expansion valve 47 (second auxiliary circuit throttle means) constitute auxiliary throttle means in the present application. Further, the liquid pipe 46 causes liquid refrigerant to flow out from the lower portion of the tank 36 and to flow into the electric expansion valve 47. The intermediate pressure return pipe 44, the electric expansion valves 43 and 47, and the gas pipe 42 and the liquid pipe 46 on the upstream side of the electric expansion valves 43 and 47 constitute an auxiliary circuit 48 in the present invention.

  With such a configuration, the electric expansion valve 33 is located downstream of the gas cooler 28 and upstream of the electric expansion valve 39. The tank 36 is located downstream of the electric expansion valve 33 and upstream of the electric expansion valve 39. Furthermore, the split heat exchanger 29 is positioned downstream of the tank 36 and upstream of the electric expansion valve 39, and the refrigerant circuit 1 of the refrigeration apparatus R in this embodiment is configured as described above.

  Various sensors are attached to various portions of the refrigerant circuit 1. That is, a high pressure sensor 49 is attached to the high pressure discharge pipe 27, and the high pressure side pressure HP of the refrigerant circuit 1 (the high pressure side discharge port 21 of the compressor 11, which is the pressure of the refrigerant discharged from the compressor 11 to the gas cooler 28). The pressure between the inlets of the electric expansion valve 33 is detected. A low pressure sensor 51 is attached to the refrigerant introduction pipe 22 to detect a low pressure LP of the refrigerant circuit 1 (pressure between the outlet of the electric expansion valve 39 and the low stage suction port 17). Further, an intermediate pressure sensor 52 is attached to the intermediate pressure suction pipe 26, and an intermediate pressure MP (the pressure between the inside of the hermetic container 12 and the high-stage side suction port 19, between the electric expansion valve and the intermediate pressure region 1 of the refrigerant circuit). The pressure in the intermediate pressure return pipe 44 after the outlets 43 and 47) is detected.

A unit outlet sensor 53 is attached to the tank outlet pipe 37 on the downstream side of the split heat exchanger 29, and this unit outlet sensor 53 detects the pressure TP in the tank 36. That is, the pressure in the tank 36 becomes the pressure of the refrigerant flowing out of the refrigerator unit 3 and flowing into the electric expansion valve 39 from the refrigerant pipe 8. Furthermore, a discharge temperature sensor 61 is attached to the high-pressure discharge pipe 27 connected to the high-stage discharge port 21 of the compressor 11 to detect the temperature (discharge temperature) of the refrigerant discharged from the compressor 11 to the gas cooler 28. To do.
A unit outlet temperature sensor 54 is attached to the tank outlet pipe 37, and a unit inlet temperature sensor 56 is attached to the refrigerant introduction pipe 22.

  These sensors 49, 51, 52, 53, 54, 56, 61 are connected to the input of the control device 57 constituting the control means of the refrigerator unit 3 composed of a microcomputer, and the float switch 55 is also connected to the control device 57. Connected to the input. The output of the control device 57 includes the electric element 13 of the compressor 11, the electric valve 25 </ b> B, the blower 31, the electric expansion valve (pressure adjusting throttle means) 33, and the electric expansion valve (first auxiliary circuit throttle means) 43. The electric expansion valve (second auxiliary circuit throttle means) 47 and the electric expansion valve (main throttle means) 39 are connected, and the control device 57 controls them based on the output of each sensor, setting data and the like.

  In the following description, it is assumed that the control device 57 controls the electric expansion valve (main throttle means) 38 on the showcase 4 side and the above-mentioned cool air circulation blower. Through a control device (not shown) on the side of the showcase 4 that operates in cooperation with the control device 57. Therefore, the control means in the present invention has a concept including the control device 57, the control device on the showcase 4 side, the main control device described above, and the like.

(2) Operation of Refrigeration Apparatus R Next, the operation of the refrigeration apparatus R with the above configuration will be described. When the electric element 13 of the compressor 11 is driven by the control device 57, the first rotary compression element 14 and the second rotary compression element 16 rotate and the first rotary compression element 14 is rotated from the low-stage suction port 17. The refrigerant gas (carbon dioxide) having a low pressure (LP: about 2.6 MPa in a normal operation state) is sucked into the low pressure portion. Then, the pressure is increased to an intermediate pressure (MP described above: about 5.5 MPa in the normal operation state) by the first rotary compression element 14 and discharged into the sealed container 12. Thereby, the inside of the airtight container 12 becomes an intermediate pressure (MP).

  Then, the intermediate-pressure refrigerant gas in the sealed container 12 enters the intercooler 24 from the low-stage discharge port 18 through the intermediate-pressure discharge pipe 23, and is air-cooled there, and then through the intermediate-pressure suction pipe 26 and the high-stage suction port. Return to 19. The intermediate pressure (MP) refrigerant gas that has returned to the high-stage suction port 19 is sucked into the second rotary compression element 16, and the second stage compression is performed by the second rotary compression element 16, resulting in a high temperature. The refrigerant gas becomes high-pressure (HP: supercritical pressure of about 9 MPa in the above-described normal operation state) and is discharged from the high-stage discharge port 21 to the high-pressure discharge pipe 27.

  The refrigerant gas discharged to the high-pressure discharge pipe 27 flows into the oil separator 20, and the oil contained in the refrigerant is separated. The separated oil passes through the oil passage 25A, and is returned to the hermetic container 12 through the electric valve 25B. The control device 57 controls the motor-operated valve 25B based on the oil level in the sealed container 12 detected by the float switch 55, and adjusts the return amount of oil to maintain the oil level in the sealed container 12.

(2-1) Control of Electric Expansion Valve 33 On the other hand, the refrigerant gas from which the oil has been separated by the oil separator 20 flows into the gas cooler 28 and is air-cooled, and then passes through the gas cooler outlet pipe 32 and then the electric expansion valve (pressure). Adjustment throttling means) 33. The electric expansion valve 33 is provided to control the high-pressure side pressure HP of the refrigerant circuit 1 upstream of the electric expansion valve 33 to a predetermined target value THP (for example, 9 MPa as described above, set as described later). The valve opening degree is controlled by the control device 57 based on the output of the high pressure sensor 49.

(2-1-1) Setting of the opening degree at the start of the electric expansion valve 33 Here, first, the control device 57 is based on the detected pressure (high pressure side pressure HP) of the high pressure sensor 49 which is an index indicating the outside air temperature. The opening of the electric expansion valve 33 at the start of R (starting opening) is set. Since there is a correlation between the high pressure side pressure HP detected by the high pressure sensor 49 and the outside air temperature, the controller 57 can determine the outside temperature from the high pressure side pressure HP. In the case of the embodiment, the control device 57 has in advance a data table showing the relationship between the high-pressure side pressure HP (outside air temperature) at the time of starting and the opening degree of the electric expansion valve 33 at the time of starting. The outside air temperature is estimated, and the electric pressure increases in proportion to the higher high pressure side pressure HP (outside air temperature) based on the above data table, and conversely decreases as the high pressure side pressure HP decreases (set in the data table). The opening degree of the expansion valve 33 when starting is set.

  This suppresses the high pressure side pressure HP of the refrigerant circuit 1 upstream of the electric expansion valve 33 from abnormally rising when the compressor 11 is started (starting of the refrigeration apparatus R) in an environment where the outside air temperature is high. As a result, the compressor 11 can be protected. Further, the high pressure side pressure HP of the compressor 11 increases particularly at the time of starting. For this reason, a protective operation for forcibly stopping the compressor 11 at a predetermined high value (abnormally high pressure) is provided. By setting the opening degree of the electric expansion valve 33 as described above, Stopping can also be suppressed or prevented.

  In the embodiment, the controller 57 estimates the outside air temperature from the high pressure side pressure HP detected by the high pressure sensor 49. However, the present invention is not limited to this, and a separate outside temperature sensor is provided to directly detect the outside air temperature. It is good (hereinafter the same).

(2-1-2) Setting of the target value THP of the high pressure side pressure HP during operation Further, the control device 57 is based on the detected pressure (high pressure side pressure HP) of the high pressure sensor 49 which is an index indicating the outside air temperature as described above. To set the target value THP described above. In this case, the control device 57 sets the target value THP in such a direction that the higher the high-pressure side pressure HP (outside air temperature), the higher the pressure, and vice versa. In this case, the standard value of the target value THP of the high pressure side pressure HP is 9 MPa as described above. The control device 57 calculates the adjustment value (number of steps) of the valve opening of the electric expansion valve 33 from the difference between the high pressure side pressure HP detected by the high pressure sensor 49 and the target value THP, and adds it to the valve opening at the time of starting described above. Thus, the electric expansion valve 33 is controlled. Thereby, the high pressure side pressure HP is controlled to the target value THP.

  In this case as well, a preset data table may be used, or may be calculated from a calculation formula. However, when the control is difficult, it is preferable to directly take in the outside temperature using the outside temperature sensor as described above.

  As a result, the target value THP during operation of the high-pressure side pressure HP upstream from the electric expansion valve 33 is high in an environment where the outside air temperature is high, and the target value THP is low in an environment where the outside air temperature is low. That is, since the target value THP increases in a situation where the high pressure side pressure HP increases due to the influence of a high outside air temperature, the valve opening degree of the electric expansion valve 33 becomes excessively large and the pressure in the tank 36 becomes too high. Can be prevented. Conversely, in a situation where the high pressure side pressure HP is low at a low outside air temperature, the target value THP is also low, so that the valve opening degree of the electric expansion valve 33 becomes excessively small and the amount of refrigerant flowing into the tank 36 is reduced. Can be prevented.

  Then, regardless of the change in the outside air temperature due to the change of season, the valve opening degree of the electric expansion valve 33 is appropriately controlled, and both the securing of the refrigeration capacity of the refrigeration apparatus R and the protection of the compressor 11 are suitably performed. Can be realized.

(2-1-3) Control with the upper limit value MHP of the high pressure side pressure HP When the control is performed as described above, the high pressure side pressure upstream of the electric expansion valve 33 due to the influence of the installation environment and load. When HP has increased to a predetermined upper limit value MHP (for example, 11 MPa or the like), the control device 57 increases the valve opening of the electric expansion valve 33 by a predetermined step. As the valve opening increases, the high-pressure side pressure HP tends to decrease, so that the high-pressure side pressure HP can always be kept below the upper limit value MHP. As a result, it is possible to reliably suppress the abnormal increase in the high-pressure side pressure HP upstream from the electric expansion valve 33 and reliably protect the compressor 11, and forcibly stop the compressor 11 due to the abnormal high pressure. (Protection operation) can be avoided in advance.

  The supercritical refrigerant gas emitted from the gas cooler 28 is liquefied by being throttled and expanded by the electric expansion valve 33, and flows into the tank 36 from the upper part via the tank inlet pipe 34, and a part thereof is evaporated. To do. The tank 36 temporarily stores and separates the liquid / gas refrigerant that has exited the electric expansion valve 33 and the high-pressure side pressure of the refrigeration apparatus R (in this case, the high-pressure discharge of the compressor 11 upstream of the tank 36). It plays a role of absorbing pressure changes in the region up to the pipe 27) and fluctuations in the refrigerant circulation rate. The liquid refrigerant accumulated in the lower part of the tank 36 flows out of the tank outlet pipe 37 (main circuit 38), and the first flow path 29A (as will be described later) in the second flow path 29B of the split heat exchanger 29. After being cooled (supercooled) by the refrigerant flowing through the auxiliary circuit 48), the refrigerant leaves the refrigerator unit 3 and flows into the electric expansion valve (main throttle means) 39 from the refrigerant pipe 8.

  The refrigerant that has flowed into the electric expansion valve 39 is squeezed there and expanded to further increase the liquid content, and flow into the evaporator 41 to evaporate. The cooling effect is exhibited by the endothermic action. The control device 57 controls the valve opening degree of the electric expansion valve 39 based on the output of a temperature sensor (not shown) that detects the temperatures of the inlet side and the outlet side of the evaporator 41 and sets the superheat degree of the refrigerant in the evaporator 41 to an appropriate value. Adjust to. The low-temperature gas refrigerant discharged from the evaporator 41 returns from the refrigerant pipe 9 to the refrigerator unit 3, and is sucked into the low-stage suction port 17 communicating with the first rotary compression element 14 of the compressor 11 through the refrigerant introduction pipe 22. It is. The above is the flow of the main circuit 38.

(2-2) Control of Electric Expansion Valve 43 Next, the flow of the auxiliary circuit 48 will be described. As described above, an electric expansion valve 43 (first auxiliary circuit throttle means) is connected to the gas pipe 42 connected to the upper portion of the tank 36, and the gas refrigerant is supplied from the upper portion of the tank 36 through the electric expansion valve 43. Flows out and flows into the first flow path 29A of the split heat exchanger 29.

  The temperature of the gas refrigerant that accumulates in the upper part of the tank 36 is reduced by evaporation in the tank 36. The gas refrigerant in the upper part of the tank 36 flows out from the gas pipe 42 constituting the auxiliary circuit 48 connected to the upper part, is throttled through the electric expansion valve 43, and then the first flow path of the split heat exchanger 29. Flows into 29A. Therefore, after the refrigerant flowing through the second flow path 29B is cooled, it joins the intermediate pressure suction pipe 26 via the intermediate pressure return pipe 44 and is sucked into the intermediate pressure portion of the compressor 11.

  The electric expansion valve 43 has a function of adjusting the pressure in the tank 36 (the pressure of the refrigerant flowing into the electric expansion valve 39) to a predetermined target value SP in addition to the function of restricting the refrigerant flowing out from the upper portion of the tank 36. Fulfill. The control device 57 controls the valve opening degree of the electric expansion valve 43 based on the output of the unit outlet sensor 53. This is because if the valve opening degree of the electric expansion valve 43 increases, the amount of gas refrigerant flowing out of the tank 36 increases and the pressure in the tank 36 decreases.

  In the embodiment, the target value SP is set to be lower than the high pressure side pressure HP and higher than the intermediate pressure MP, for example, 6 MPa. Then, the controller 57 adjusts the valve opening degree of the electric expansion valve 39 from the difference between the pressure TIP in the tank 36 detected by the unit outlet sensor 53 (pressure of the refrigerant flowing into the electric expansion valve 39) and the target value SP ( The number of steps) is calculated and added to the valve opening at the time of starting to be described later, and the pressure TIP in the tank 36 (pressure of the refrigerant flowing into the electric expansion valve 39) is controlled to the target value SP. That is, when the pressure TIP in the tank 36 rises above the target value SP, the valve opening degree of the electric expansion valve 43 is increased so that the gas refrigerant flows out of the tank 36 into the gas pipe 42, and conversely from the target value SP. When it descends, the valve opening is reduced and controlled to close.

(2-2-1) Setting of the opening degree at the start of the electric expansion valve 43 Here, the control device 57 detects the pressure detected by the high-pressure sensor 49 (high-pressure side pressure HP), which is an index indicating the outside air temperature, or the outside air as described above. In the case where a temperature sensor is provided, the valve opening degree (starting opening degree) of the electric expansion valve 43 when starting the refrigeration apparatus R is set based on the directly detected outside air temperature). In the case of the embodiment, as described above, the control device 57 has in advance a data table indicating the relationship between the high-pressure side pressure HP (outside air temperature) at the time of starting and the valve opening degree at the time of starting the electric expansion valve 43.

  Then, the control device 57 estimates the outside air temperature at the time of starting, and increases according to the high pressure side pressure HP (outside air temperature) based on the data table, and conversely decreases (the data table) as the high pressure side pressure HP decreases. The valve opening at the start of the electric expansion valve 43 is set. Thereby, it is possible to suppress an increase in the pressure in the tank 36 at the time of start-up in an environment where the outside air temperature is high, and to prevent an increase in the pressure of the refrigerant flowing into the electric expansion valve 39.

  In the embodiment, as described above, the target value SP of the pressure TIP in the tank 36 (pressure of the refrigerant flowing into the electric expansion valve 39) is fixed to 6 MPa, but in the case of the electric expansion valve 33, Similarly to the above, the target value SP may be set based on the detected pressure (high pressure side pressure HP) of the high pressure sensor 49 which is an index indicating the outside air temperature. In this case, the target value SP is set in such a direction that the higher the high pressure side pressure HP (outside air temperature) is, the lower the pressure is higher.

  Therefore, in an environment where the outside air temperature is high, the target value SP during operation of the pressure of the refrigerant flowing into the electric expansion valve 39 is high, and in an environment where the outside air temperature is low, the target value SP is low. In other words, in a situation where the pressure increases due to the influence of a high outside air temperature, the target value SP of the pressure of the refrigerant flowing into the electric expansion valve 39 increases, so that the valve opening degree of the electric expansion valve 43 becomes excessively large and the auxiliary circuit Thus, it is possible to prevent inconvenience of excessive flow of the refrigerant to the 48. On the other hand, when the pressure is low at a low outside air temperature, the target value SP of the pressure of the refrigerant flowing into the electric expansion valve 39 is also low, so that the valve opening degree of the electric expansion valve 43 becomes too small and flows into the auxiliary circuit 48. This makes it possible to prevent the disadvantage that the amount of refrigerant to be reduced is excessively reduced. As a result, the amount of refrigerant flowing in the auxiliary circuit 48 can be accurately adjusted by appropriately controlling the valve opening degree of the electric expansion valve 43 regardless of the change in the outside air temperature accompanying the change in season.

(2-2-2) Control of tank internal pressure TIP with specified value MTIP Note that when the control is performed as described above, the internal pressure TIP (electric expansion valve 39 in the electric expansion valve 39) is affected by the installation environment and load. When the pressure of the refrigerant flowing in) increases to a predetermined specified value MTIP (for example, 7 MPa or the like), the control device 57 increases the valve opening degree of the electric expansion valve 43 by a predetermined step. As the valve opening increases, the pressure TIP in the tank 36 tends to decrease, so that the pressure TIP can always be maintained below the specified value MTIP. It becomes possible to reliably achieve the effect of suppressing the pressure of the refrigerant conveyed to the valve 39.

(2-3) Control of the electric expansion valve 47 The electric expansion valve 47 (second auxiliary circuit throttle means) is connected to the liquid pipe 46 connected to the lower portion of the tank 36 as described above. The liquid refrigerant flows out from the lower portion of the tank 36 via the electric expansion valve 47, merges with the gas refrigerant from the gas pipe 42, and flows into the first flow path 29 </ b> A of the split heat exchanger 29.

  That is, the liquid refrigerant that accumulates in the lower part of the tank 36 flows out from the liquid pipe 46 that constitutes the auxiliary circuit 48 connected to the lower part, is throttled through the electric expansion valve 47, and then the first of the split heat exchanger 29. It flows into the flow path 29A and evaporates there. The heat absorption at this time increases the supercooling of the refrigerant flowing through the second flow path 29B, and then merges with the intermediate pressure suction pipe 26 via the intermediate pressure return pipe 44 and sucks into the intermediate pressure portion of the compressor 11. It is.

  In this way, the electric expansion valve 47 throttles the liquid refrigerant flowing out from the lower part of the tank 36, evaporates it in the first flow path 29A of the split heat exchanger 29, and the refrigerant of the main circuit 38 that flows into the second flow path 29B. The control device 57 adjusts the amount of liquid refrigerant flowing through the first flow path 29A of the split heat exchanger 29 by controlling the valve opening degree of the electric expansion valve 47.

  When the amount of supercooling of the refrigerant in the main circuit 38 in the split heat exchanger 29 increases, the liquid phase ratio of the refrigerant conveyed to the electric expansion valve 39 increases, so that the electric expansion valve 39 has a full refrigerant. Will flow in, and the temperature of the refrigerant sucked by the compressor 11 will also decrease. As a result, the discharge temperature of the refrigerant discharged from the compressor 11 to the gas cooler 28 also decreases.

  Therefore, the control device 57 controls the opening degree of the electric expansion valve 47 based on the temperature (discharge temperature) of the refrigerant discharged from the compressor 11 to the gas cooler 28 detected by the discharge temperature sensor 61, thereby performing split heat exchange. The amount of liquid refrigerant flowing through the first flow path of the vessel 29 is adjusted, and the discharge temperature of the refrigerant discharged from the compressor 11 to the gas cooler 28 is controlled to a predetermined target value TDT. That is, when the actual discharge temperature is higher than the target value TDT, the opening degree of the electric expansion valve 47 is increased, and when the actual discharge temperature is lower, the opening is reduced. Thereby, the discharge temperature of the refrigerant of the compressor 11 is maintained at the target value TDT, and the compressor 11 is protected.

  In that case, based on the detected pressure (low pressure side pressure LP) of the low pressure sensor 51, which is an index indicating the refrigerant evaporation temperature in the evaporator 41, the control device 57 lowers and lowers the lower pressure LP (evaporation temperature). The target value TDT of the refrigerant discharge temperature of the compressor 11 is changed in such a direction as to increase it. For example, when the evaporation temperature is lower than −20 ° C., the target value TDT is set to + 70 ° C., and when the evaporation temperature is −20 ° C. or higher, the target value TDT is changed to + 100 ° C.

  This ensures supercooling of the refrigerant in the main circuit 38 in the second flow path 29B of the split heat exchanger 29, particularly under refrigeration conditions (such as a refrigeration showcase) where the evaporation temperature in the evaporator 41 is high, and refrigerating capacity is increased. It can be maintained stably.

(2-4) Actual Operation of Refrigeration Apparatus R for Each Outside Air Temperature Next, the actual operation status of the refrigeration apparatus R will be described for each outside air temperature with reference to the PH diagrams of FIGS.

(2-4-1) Interim period FIG. 2 shows an intermediate period environment where the outside air temperature is about + 25 ° C., for example. As described above, the control device 57 controls the valve opening degree of the electric expansion valve 33 to control the high-pressure side pressure HP upstream from the electric expansion valve 33 to the target value THP. To adjust the amount of the gas refrigerant flowing out from the gas pipe 42, and the pressure TIP in the tank 36 (the pressure of the refrigerant flowing into the electric expansion valve 39) is controlled to the target value SP. Further, the valve opening degree of the electric expansion valve 47 is controlled to adjust the amount of liquid refrigerant flowing out from the liquid pipe 46, and the refrigerant discharge temperature of the compressor 11 is adjusted to the target value TDT.

  A line descending from X1 to X2 in FIG. The pressure of X2 (pressure TIP in the tank 36) is adjusted to the target value SP by the electric expansion valve 43. The liquid / gas is separated from the tank 36 at X2, and the line from X2 to the left indicates the supercooling of the liquid refrigerant toward the electric expansion valve 39 of the main circuit 38. Similarly, the electric expansion valve 39 throttles the pressure at X3 and the pressure drops (the same applies to FIG. 3).

  Since the intermediate pressure MP becomes low in the intermediate period, there is a difference from the pressure TIP in the tank 36 adjusted by the electric expansion valve 43. As a result, the split heat exchanger 29 can secure a heat exchange amount necessary for the supercooling of the refrigerant in the main circuit 38, so that the refrigerant circuit 1 has a two-stage expansion cycle and a so-called split cycle combined cycle. Become.

(2-4-2) At high outdoor temperatures (summer, etc.)
FIG. 3 shows a case where the outside air temperature is an environment (summer season or the like) where the outside air temperature is + 30 ° C. or higher. At such a high outside air temperature, the intermediate pressure MP becomes high and there is no difference from the pressure TIP in the tank 36. Therefore, the heat exchange amount in the split heat exchanger 29 is reduced, and the refrigerant of the main circuit 38 is reduced. Overcooling cannot be secured. Further, since the high-pressure side pressure HP tends to increase, the valve opening of the electric expansion valve 33 is increased from that in the intermediate period in order to suppress it (control by the control device 57).

  Therefore, the amount of refrigerant flowing into the tank 36 increases, but the control device 57 controls the valve of the electric expansion valve 43 in order to suppress an increase in the pressure TIP (pressure of the refrigerant flowing into the electric expansion valve 39) in the tank 36. Increase the opening. For this reason, the amount of refrigerant returned to the intermediate pressure portion (intermediate pressure suction pipe 26) of the compressor 11 increases, so that the intermediate pressure MP increases. Therefore, the refrigerant subcooling effect of the main circuit 38 in the split heat exchanger 29 is reduced, and the refrigerant circuit 1 becomes a so-called two-stage expansion cycle.

(2-4-3) At low outside temperatures (winter etc.)
Next, FIG. 4 shows a time when the outside air temperature is lowered to + 20 ° C. or lower (in winter). At such a low outside air temperature, the high pressure side pressure HP is low, but the target value THP is also low as described above, so that the valve opening degree of the electric expansion valve 33 is almost fully open. Therefore, the pressure TIP in the tank 36 becomes a pressure close to the high-pressure side pressure HP, and the effect of the tank 36 is reduced. However, the refrigerant that has exited the gas cooler 28 is liable to be liquefied due to the low outside air temperature. The refrigerant that has entered the tank 36 via the valve 33 is almost liquefied, and a large amount of liquid refrigerant is stored in the tank 36.

  Therefore, since the liquid refrigerant is throttled in the electric expansion valves 43 and 47 and evaporates in the first flow path 29A of the split heat exchanger 29, the effect of the split heat exchanger 29 increases, and the main circuit 38 The refrigerant in the (second flow path 29B) can be supercooled, and the refrigerant circuit 1 enters a split cycle.

  As described in detail above, in the present invention, the electric expansion valve 33 connected to the refrigerant circuit 1 downstream of the gas cooler 28 and upstream of the electric expansion valve 39, and downstream of the electric expansion valve 33. A tank 36 connected to the refrigerant circuit 1 upstream of the electric expansion valve 39; a split heat exchanger 29 provided in the refrigerant circuit 1 downstream of the tank 36 and upstream of the electric expansion valve 39; An auxiliary circuit 48 that causes the refrigerant in 36 to flow into the first flow path 29A of the split heat exchanger 29 via the electric expansion valve 43 and the electric expansion valve 47 and then sucked into the intermediate pressure portion of the compressor 11; A main circuit 38 that causes the refrigerant to flow out from the lower portion of the tank 36, flows into the second flow path 29B of the split heat exchanger 29, exchanges heat with the refrigerant flowing through the first flow path 29A, and then flows into the electric expansion valve 39. It is equipped with auxiliary times The refrigerant flowing in the first flow path 29A of the split heat exchanger 29 constituting 48 is expanded by the electric expansion valves 43 and 47, and flows to the second flow path 29B of the split heat exchanger 29 constituting the main circuit 38. The refrigerant can be supercooled, and the specific enthalpy at the inlet of the evaporator 41 can be reduced to effectively improve the refrigerating capacity.

  Further, since the refrigerant flowing through the first flow path 29A of the split heat exchanger 29 is returned to the intermediate pressure portion of the compressor 11, the amount of refrigerant sucked into the low pressure portion of the compressor 11 is reduced, and from low pressure to intermediate pressure. The amount of compression work in the compressor 11 for compression is reduced. As a result, the compression power in the compressor 11 is reduced and the coefficient of performance is improved.

  Furthermore, a part of the refrigerant liquefied by expansion by the electric expansion valve 33 evaporates in the tank 36 to become a gas refrigerant having a lowered temperature, and the rest becomes liquid refrigerant and is temporarily stored in the lower part of the tank 36. It becomes a shape. The liquid refrigerant in the lower part of the tank 36 flows into the electric expansion valve 39 through the second flow path 29B of the split heat exchanger 29 constituting the main circuit 38. It becomes possible to allow the refrigerant to flow into 39, and it is possible to improve the refrigerating capacity especially under refrigeration conditions where the evaporation temperature in the evaporator 41 is high. Furthermore, since the tank 36 has the effect of absorbing the fluctuation of the circulating refrigerant amount in the refrigerant circuit 1, the refrigerant filling amount error is also absorbed.

  In particular, since the electric expansion valve 33 is controlled by the control device 57 and the high pressure side pressure HP of the refrigerant circuit 1 upstream of the electric expansion valve 33 is adjusted by the electric expansion valve 33, the compressor 11 The high-pressure side pressure HP at which the refrigerant is discharged becomes high, so that the operation efficiency of the compressor 11 is lowered, or the inconvenience of causing damage to the compressor 11 can be avoided.

  In this case, the control device 57 sets the opening degree at the start of the electric expansion valve 33 in a direction that increases as the outside air temperature increases based on the index representing the outside air temperature. The increase in the high-pressure side pressure HP can be suppressed, and the compressor 11 can be protected.

  Further, the control device 57 controls the valve opening degree of the electric expansion valve 33 to control the high-pressure side pressure HP of the refrigerant circuit 1 upstream of the electric expansion valve 33 to a predetermined target value THP, and the outside air temperature. Since the target value THP of the high-pressure side pressure HP is set in the direction of increasing the higher the outside air temperature based on the index representing the pressure, the high-pressure side pressure HP upstream of the electric expansion valve 33 is being operated in an environment where the outside air temperature is high. The target value THP becomes low and the target value THP becomes low in an environment where the outside air temperature is low.

  As a result, the target value THP increases in a situation where the high-pressure side pressure HP increases due to the influence of a high outside air temperature, so that the valve opening degree of the electric expansion valve 33 becomes excessively large and the internal pressure of the tank 36 becomes too high. Can be prevented. Conversely, in a situation where the high pressure side pressure HP is low at a low outside air temperature, the target value THP is also low, so that the valve opening degree of the electric expansion valve 33 becomes excessively small and the amount of refrigerant flowing into the tank 36 is reduced. Can be prevented.

  As a result, it is possible to appropriately realize both the securing of the refrigerating capacity and the protection of the compressor 11 by appropriately controlling the opening degree of the electric expansion valve 33 regardless of the change in the outside air temperature accompanying the change in season. It becomes like this.

  Further, when the high pressure side pressure HP of the refrigerant circuit 1 upstream of the electric expansion valve 33 is increased to a predetermined upper limit value MHP, the control device 57 increases the valve opening degree of the electric expansion valve 33, so that the high pressure side pressure HP is increased. Can always be kept below the upper limit value MHP. As a result, the compressor 11 can be reliably protected by accurately suppressing an abnormal increase in the high-pressure side pressure HP upstream from the electric expansion valve 33, and the compressor 11 can be stopped (protective operation) due to an abnormal high pressure. ) Can be avoided in advance.

  In addition, an electric expansion valve 43 is provided, the auxiliary circuit 48 has a gas pipe 42 through which refrigerant flows out from the upper portion of the tank 36 and flows into the electric expansion valve 43, and the control device 57 is operated by the electric expansion valve 43. Since the pressure TIP of the refrigerant flowing into the engine 39 is adjusted, the electric expansion valve 43 controls the pressure TIP of the refrigerant conveyed to the electric expansion valve 39 while suppressing the influence of the fluctuation of the high-pressure side pressure HP. Will be able to.

  Further, by lowering the pressure TIP of the refrigerant flowing into the electric expansion valve 39 by the electric expansion valve 43, it is possible to use a pipe having a low pressure resistance as the pipe reaching the electric expansion valve 39. Thereby, it becomes possible to improve workability and construction cost.

  In particular, when the low temperature gas is extracted from the upper part of the tank 36 via the electric expansion valve 43, the pressure in the tank 36 is reduced. As a result, the temperature is lowered in the tank 36, so that the refrigerant condenses, and the liquid refrigerant can be effectively stored in the tank 36.

  In this case, since the control device 57 sets the opening degree of the electric expansion valve 43 at the time of starting the electric expansion valve 43 in such a direction that the higher the outside air temperature is, based on the index representing the outside air temperature, the starting time in the environment where the outside air temperature is high. It is possible to suppress an increase in the pressure in the tank 36 and to prevent an increase in the pressure of the refrigerant flowing into the electric expansion valve 39.

  Further, the control device 57 controls the valve opening degree of the electric expansion valve 43 to control the pressure TIP of the refrigerant flowing into the electric expansion valve 39 to a predetermined target value SP, and based on an index representing the outside air temperature, If the target value SP of the pressure of the refrigerant flowing into the electric expansion valve 39 is set so as to increase as the outside air temperature increases, the pressure TIP of the refrigerant flowing into the electric expansion valve 39 in an environment where the outside air temperature is high. The target value SP during operation increases, and the target value SP decreases in an environment where the outside air temperature is low.

  As a result, in a situation where the pressure increases due to the influence of a high outside air temperature, the target value SP of the pressure TIP of the refrigerant flowing into the electric expansion valve 39 increases, so that the valve opening degree of the electric expansion valve 43 becomes excessively large. It is possible to prevent the inconvenience that the refrigerant flows excessively in the auxiliary circuit 48. On the other hand, in a situation where the pressure becomes low at a low outside air temperature, the target value SP of the pressure TIP of the refrigerant flowing into the electric expansion valve 39 also becomes low, so that the valve opening degree of the electric expansion valve 43 becomes too small and the auxiliary circuit 48 It is possible to prevent a disadvantage that the amount of refrigerant flowing in is excessively reduced. As a result, the amount of refrigerant flowing in the auxiliary circuit 48 can be accurately adjusted by appropriately controlling the valve opening degree of the electric expansion valve 43 regardless of the change in the outside air temperature accompanying the change in season.

  Further, when the pressure of the refrigerant flowing into the electric expansion valve 39 rises to a predetermined specified value MTIP, the control device 57 increases the valve opening degree of the electric expansion valve 43, so that the refrigerant conveyed to the electric expansion valve 39 is increased. It becomes possible to always maintain the pressure TIP below the specified value MTIP, and it is possible to reliably achieve the effect of suppressing the influence of the high pressure side pressure fluctuation and the effect of suppressing the pressure of the refrigerant conveyed to the electric expansion valve 39. Become.

  In addition, an electric expansion valve 47 is provided, and the auxiliary circuit 48 has a liquid pipe 46 through which refrigerant flows out from the lower portion of the tank 36 and flows into the electric expansion valve 47, and the controller 57 controls the valve opening degree of the electric expansion valve 47. By controlling the amount of liquid refrigerant flowing through the first flow path 29A of the split heat exchanger 29, the discharge temperature of the refrigerant discharged from the compressor 11 to the gas cooler 28 is controlled to a predetermined target value TDT. Therefore, the liquid refrigerant in the lower part of the tank 36 is caused to flow through the first flow path 29A of the split heat exchanger 29 via the electric expansion valve 47, and the main circuit 38 flowing through the second flow path 29B of the split heat exchanger 29 is supplied. The supercooling of the refrigerant can be increased.

  Thereby, the liquid phase ratio of the refrigerant conveyed to the electric expansion valve 39 can be increased and can be made to flow into the electric expansion valve 39 in a full state. Further, since the temperature of the refrigerant sucked by the compressor 11 is also lowered, as a result, the refrigerant discharge temperature discharged from the compressor 11 to the gas cooler 28 can be lowered to the target value TDT. It is possible to protect the compressor 11.

  In this case, the control device 57 changes the target value TDT of the refrigerant discharge temperature in a direction to lower the higher the evaporation temperature based on the index representing the refrigerant evaporation temperature in the evaporator 41. Under refrigeration conditions where the evaporation temperature is high, it is possible to ensure supercooling of the refrigerant in the main circuit 38 in the split heat exchanger 29 and stably maintain the refrigeration capacity.

Next, the configuration of the refrigerator unit 3 in the refrigeration cycle shown in FIG. 1 will be described with reference to FIGS.
FIG. 5 is a perspective view schematically showing a state in which the front cover of the refrigerator unit 3 is removed. FIG. 6 is a front view schematically showing a state in which the front cover of the refrigerator unit 3 is removed. FIG. 7 is an exploded perspective view of the unit body 100. In the following description, “up / down”, “front / rear”, and “left / right” refer to upper / lower, front / rear, and left / right when the refrigerator unit 3 is viewed from the front.

  As shown in FIGS. 5 and 6, the refrigerator unit 3 includes a unit main body 100 and a front cover (not shown) attached to the front surface of the unit main body 100. The unit main body 100 includes a heat exchange chamber 30 that is a right chamber, a machine chamber 40 that is a lower half chamber of a left chamber, and an electrical component chamber 60 that is an upper half chamber of the left chamber. The refrigerator unit 3 of the present embodiment is a so-called side flow type refrigerator unit 3.

In the unit main body 100, a plane substantially L-shaped intercooler 24 and a gas cooler 28 are arranged from the right side surface of the unit main body 100 to the back surface. The intercooler 24 and the gas cooler 28 are provided so as to overlap each other.
The intercooler 24 and the gas cooler 28 provided on the right side surface of the unit main body 100 are provided approximately equal to the length in the front-rear direction of the unit main body 100. The intercooler 24 and the gas cooler 28 provided on the back surface of the unit main body 100 are provided with a width of about three quarters from the right side in the right direction of the unit main body 100.
A rear cover 72 that is substantially L-shaped when viewed from above is provided on the left rear portion of the unit body 100. The right end portion of the rear cover 72 is fixed to the left end portions of the intercooler 24 and the gas cooler 28. The front end portion of the rear cover 72 is fixed to the electrical equipment chamber 60.
A corner cover 77 is provided outside the intercooler 24 and the gas cooler 28 at the right rear corner of the unit body 100.

  In the refrigerator unit 3, a partition plate 70 that divides the room into two parts left and right is provided in the substantially central portion of the interior over the entire vertical direction. The partition plate 70 is bent obliquely leftward as viewed from above, and the rear end portions of the partition plate 70 are fixed to the left end portions of the intercooler 24 and the gas cooler 28. Further, the partition plate 70 is fixedly provided with a shelf plate 71 for disposing the electrical equipment chamber 60 in the upper half chamber in the left side chamber.

  With such a configuration, inside the refrigerator unit 3, the heat exchange chamber 30 that is the right chamber, the machine chamber 40 that is the lower half chamber of the left chamber, and the electrical room 60 that is the upper half chamber of the left chamber. And are formed.

In the heat exchange chamber 30, an oil separator 20 and a blower 31 are provided. As shown in FIG. 7, the blower 31 includes a U-shaped support 136 in a side view, a fan motor 132 provided on the support 136 at two locations above and below, a rotating shaft 133 provided on the fan motor 132, and a rotating shaft. And a fan body 134 attached to 133.
As shown in FIG. 5, the blower 31 is disposed at the front side in the front-rear direction, at the center in the width direction of the heat exchange chamber 30 in such a direction that the fan body 134 faces forward. The blower 31 is fixed by fixing the upper surface of the support 136 and the upper surface of the intercooler 24 by the support plate 35.

An oil separator 20 is provided at the left rear of the heat exchange chamber 30, that is, at a position close to the partition plate 70 and close to the gas cooler 28. The oil separator 20 is positioned on the front side of the gas cooler 28 and is disposed on the rear side of the fan body 134. Further, the oil separator 20 is disposed at a position close to the partition plate 70 so that the refrigerant pipe connected to the oil separator 20 can be disposed in the machine chamber 40 without being disposed in the heat exchange chamber 30 as much as possible.
A refrigerant pipe is connected to the upper portion of the oil separator 20, and the refrigerant pipe extends to the machine chamber 40 through a connection hole 78 provided in the lower portion of the partition plate 70.

The machine room 40 is provided with the compressor 11, the tank 36, and a refrigerant pipe that connects them.
The machine room 40 is provided with a partition wall 73 that divides the machine room 40 into left and right. On the outside (left side) of the partition wall 73, an air passage S1 for cooling air is formed.
The air passage S1 is surrounded by a partition wall 73 and a support plate 74 that divides the lower half of the machine room 40 into the front and rear. The support plate 74 has substantially half the height of the partition wall 73, and the upper portion of the support plate 74 is not divided into the front and the rear of the machine room 40, and the space extends in the front and rear of the machine room 40. In the air passage S1, a unit outlet 6 fixed to the support plate 74 and a unit inlet 7 fixed to the partition wall 73 are provided. A bottom plate of the unit main body 100 is located below the air passage S1, and a vent hole 76 is provided in the bottom plate.

  A machine element space S <b> 2 surrounded by the bottom plate of the electrical chamber 60, the partition wall 73, and the partition plate 70 is provided on the inner side (right side) of the partition wall 73. In the machine element space S2, a compressor 11, a refrigerant pipe, and the like are arranged. The refrigerant pipes are provided densely across the machine chamber 40 in the width between the partition wall 73 and the compressor 11.

  A tank space S3 is provided behind the air passage S1, that is, behind the support plate 74, and a tank 36 is provided in the tank space S3. The tank space S3 and the air passage S1 are separated by a support plate 74, but are not separated above the support plate 74, and are connected spaces.

  Above the machine room 40, an electrical equipment room 60 including an electronic circuit board and the like is provided. A slit 75 is provided on the side wall of the electrical component chamber 60 on the heat exchange chamber 30 side. The slit 75 communicates with a slit (not shown) provided in the partition plate 70, and the electrical component chamber 60 and the machine chamber 40 communicate with each other through these slits.

In the present embodiment, first, by operating the compressor 11, the refrigerant sent from the showcase 41 is sucked from the low-stage suction port 17 of the compressor 11, and this refrigerant is the first rotary compression element 14. By this, it is compressed to an intermediate pressure and discharged from the low-stage discharge port 18.
In addition, the refrigerant discharged from the low-stage discharge port 18 of the compressor 11 flows into the intercooler 24 through the intermediate pressure discharge pipe 23, and is cooled by heat exchange with the outside air by the blower 31 in this intercooler 24. It is returned to the high stage side inlet 19 of the machine 11.

The refrigerant returned from the intercooler 24 is compressed to a required pressure by the second rotary compression element 16 by the compressor 11 and discharged from the high-stage discharge port 21, and is sent to the gas cooler 28 through the oil separator 20. The refrigerant sent from the compressor 11 is cooled by exchanging heat with the outside air by the blower 31 by the gas cooler 28 and sent to the tank 36 as a high-pressure refrigerant.
The refrigerant that has been depressurized and cooled in the tank 36 is sent to the refrigeration load (evaporator 41) such as the showcase 4 through the unit outlet 6, and in this evaporator 41, heat is exchanged with the internal air to store the refrigerant. Inside cooling is performed. The refrigerant after heat exchange in the evaporator 41 is returned to the compressor 11 via the unit inlet 7 and the refrigerant introduction pipe 22.

In the refrigerator unit 3, the outside air sucked by the blower 31 passes through the intercooler 24 and the gas cooler 28, passes through the heat exchange chamber 30, and is discharged through the front unit (not shown). At this time, the outside air sucked in by the blower 31 hits the oil separator 20 arranged in the heat exchange chamber 30, and the oil stored in the oil separator 20 is cooled.
By disposing the oil separator 20 in the heat exchange chamber 30, the oil temperature can be lowered by about 5 ° C. as compared with the case where the oil separator 20 is disposed in the machine chamber 40.

  As described above, according to the present embodiment, since the oil separator 20 provided in the discharge portion of the compressor 11 is disposed in the blowing path of the blower 31, the oil separator 20 can be cooled by the blowing of the blower 31.

Further, according to the present embodiment, the intercooler 24 and the gas cooler 28 are opened on the back surface of the unit main body 100, and the blower 31 is disposed on the front side in the front-rear direction of the unit main body 100.
According to this structure, since the ventilation path | route of the air blower 31 is formed from the back surface of the unit main body 100 to a front surface, the oil in the oil separator 20 can be cooled efficiently by the ventilation of the air blower 31. Further, since the blower 31 is disposed on the front side in the front-rear direction of the unit main body 100, a space that does not contact the fan body 134 can be secured even if the oil separator 20 is disposed in the heat exchange chamber 30.

Further, according to the present embodiment, the oil separator 20 is disposed adjacent to the partition plate 70.
According to this configuration, since the oil separator 20 is disposed near the partition plate 70, the length of the refrigerant pipe extending into the heat exchange chamber 30 can be shortened.

  As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to this embodiment. Since only one embodiment of the present invention is illustrated, changes and applications can be arbitrarily made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Refrigerant circuit 3 Refrigerator unit 11 Compressor 20 Oil separator 24 Intercooler 28 Gas cooler 30 Heat exchange chamber 31 Blower 36 Tank 40 Machine room 60 Electrical room 70 Partition plate 75 Slit 78 Connection hole 100 Unit main body 132 Fan motor 133 Rotating shaft 134 Fan Body 136 Support

Claims (2)

In a refrigerator unit including a machine room in which a compressor is disposed, an outdoor heat exchanger, and a heat exchange chamber in which a blower is disposed.
The outdoor heat exchanger is disposed along the back surface from the side of the heat exchange chamber;
The outdoor heat exchanger extends to the rear of the machine room in a front view,
A partition plate that partitions the machine room and the heat exchange chamber in the center of the unit body is provided over the entire vertical direction,
The partition plate is bent obliquely over the rear in a top view,
The rear end of the partition plate is fixed to the end of the outdoor heat exchanger,
The blower is disposed on the front surface of the unit body,
An oil separator provided in a discharge part of the compressor is disposed between the outdoor heat exchanger and the blower, at a position overlapping the blower in a front view and adjacent to the partition plate. did,
A refrigerator unit characterized by that. 2. The refrigerator unit according to claim 1 , wherein carbon dioxide refrigerant is used as a refrigerant for the refrigeration cycle .

Images