Refrigerator

Abstract

To facilitate replacement or repair of a sensor for refrigerant leakage detection used for a refrigerator for a storage box such as a container in case of breakdown, a sensor for refrigerant leakage detection is disposed outside of an internal space of a storage box, and an internal air guide passage is provided which guides internal air from a discharge side of a fan provided in the internal space of the storage box to the sensor for refrigerant leakage detection.

Claims

1. A refrigerator, comprising a casing mounted to a storage box, a refrigerant circuit including an evaporator cooling internal air in the storage box and a condenser disposed outside the storage box, and a sensor for refrigerant leakage detection detecting a leakage of a refrigerant from the refrigerant circuit, the sensor for refrigerant leakage detection being disposed outside of an internal space of the storage box, and an internal air guide passage guiding the internal air from a discharge side of a fan disposed in the internal space of the storage box to the sensor for refrigerant leakage detection, wherein an air-inlet side end of the internal air guide passage is disposed at a discharge side of the fan and an air-outlet side end of the internal air guide passage is disposed at an intake side of the fan.

2. The refrigerator of claim 1, wherein the sensor for refrigerant leakage detection is disposed at least partially outside of the storage box with respect to a thermal insulator disposed in the casing.

3. The refrigerator of claim 2, wherein an air-inlet side end of the internal air guide passage is disposed at a discharge side of the fan and an air-outlet side end of the internal air guide passage is disposed at an intake side of the fan.

4. The refrigerator of claim 2, wherein the air-inlet side end of the internal air guide passage is disposed downstream of airflow passing through the evaporator.

5. The refrigerator of claim 4, wherein the air-inlet side end of the internal air guide passage is disposed below the evaporator.

6. The refrigerator of claim 2, wherein an interior wall of the casing guides air flowing in the internal space of the storage box into the internal air guide passage.

7. The refrigerator of claim 2, wherein the sensor for refrigerant leakage detection is disposed downstream of airflow passing through the condenser.

8. The refrigerator of claim 2, wherein the sensor for refrigerant leakage detection is disposed in a vicinity of an outlet of a ventilation port provided in the casing of the storage box.

9. The refrigerator of claim 2, wherein the storage box is a container main body used for transportation of a cargo, and the casing is configured to be mounted to the container main body.

10. The refrigerator of claim 1, wherein the air-inlet side end of the internal air guide passage is disposed downstream of airflow passing through the evaporator.

11. The refrigerator of claim 10, wherein the air-inlet side end of the internal air guide passage is disposed below the evaporator.

12. The refrigerator of claim 1, wherein an interior wall of the casing guides air flowing in the internal space of the storage box into the internal air guide passage.

13. The refrigerator of claim 1, wherein the sensor for refrigerant leakage detection is disposed downstream of airflow passing through the condenser.

14. The refrigerator of claim 1, wherein the sensor for refrigerant leakage detection is disposed in a vicinity of an outlet of a ventilation port provided in the casing of the storage box.

15. The refrigerator of claim 1, wherein the storage box is a container main body used for transportation of a cargo, and the casing is configured to be mounted to the container main body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view illustrating a container refrigerator according to an embodiment as viewed from outside of the box.

(2) FIG. 2 is a lateral cross-sectional view illustrating a configuration of the container refrigerator.

(3) FIG. 3 is a piping diagram illustrating a configuration of a refrigerant circuit.

(4) FIG. 4 is a front view of the container refrigerator.

(5) FIG. 5 is a back view of the container refrigerator.

(6) FIG. 6 is a cross-sectional view taken along line VI-VI shown in FIG. 5.

(7) FIG. 7 is a front view of a container refrigerator according to a first variation of the embodiment.

(8) FIG. 8 is a lateral cross-sectional view of the container refrigerator according to the first variation of the embodiment.

(9) FIG. 9 is a front view of a container refrigerator according to a second variation of the embodiment.

(10) FIG. 10 is a lateral cross-sectional view of the container refrigerator according to the second variation of the embodiment.

DESCRIPTION OF EMBODIMENTS

(11) In the following, an embodiment will be described in detail with reference to the drawings. The following embodiment relates to a container refrigerator, which is one kind of refrigerators cooling the inside of a storage box. Note that the following description of the embodiment is merely an example in nature, and is not intended to limit the scope, applications, or use of the present disclosure.

(12) A shown in FIG. 1 and FIG. 2, the container refrigerator (10) refrigerates a cargo storage space (S3) for a container main body (storage box) (11) used for marine transportation or land transportation. The container refrigerator (10) includes a refrigerant circuit (20) cooling air in an internal space (S2, S3) of the container main body (11) through using a refrigeration cycle (see FIG. 3). The internal space (S2, S3) includes a cargo storage space (S3) in which plants (15) such as grapes are boxed and stored, and an internal storage space (S2) in which a part of a refrigerant circuit described later is stored.

(13) The container main body (11) is formed into a shape of a box with one side open. A casing (12) is mounted to and covers the opening end of the container main body. The casing (12) includes an exterior wall (12a) disposed outside the container main body (11), and an interior wall (12b) disposed inside the container main body (11). The exterior and interior walls (12a) and (12b) may be made of an aluminum alloy, for example.

(14) The exterior wall (12a) is mounted to the periphery of the opening of the container main body (11) so as to close the end of the opening of the container main body (11). The exterior wall (12a) is formed such that the lower part of the exterior wall (12a) swells into the container main body (11).

(15) The interior wall (12b) is disposed to face the exterior wall (12a). The interior wall (12b) swells into the container main body just like the lower part of the exterior wall (12a). A thermal insulator (12c) fills the space between the interior and exterior walls (12b, 12a).

(16) The lower part of the casing (12) is formed so as to swell into the container main body (11). Thus, an external storage space (S1) is formed outside the container main body (11) and in the lower part of the casing (12), and the internal storage space (S2) is formed inside the container main body (11) and in the upper part of the casing (12).

(17) The casing (12) is provided with two opening/closing doors (16) which are arranged side by side in a width direction and can open and close at the time of maintenance. The external storage space (S1) of the casing (12) includes an electric component box (17) adjacent to an external fan (25) described later.

(18) A partition plate (18) is disposed between the internal spaces (S2, S3) of the container main body (11). This partition plate (18) is formed by a substantially rectangular plate member, and stands upright so as to face to the wall of the casing (12) facing the interior of the container main body (11). This partition plate (18) separates the internal storage space (S2) from the cargo storage space (S3) in the container main body (11).

(19) An intake port (18a) is formed between the upper end of the partition plate (18) and a ceiling surface of the container main body (11). Air in the cargo storage space (S3) of the container main body (11) is taken into the internal storage space (S2) through the intake port (18a).

(20) A floorboard (19) is disposed in the container main body (11) with a clearance interposed between the floorboard (19) and the bottom surface of the container main body (11). Boxed plants (15) are placed on the floorboard (19). An air flow path (19a) is formed between the floorboard (19) and the bottom surface of the container main body (11). The clearance left between the lower end of the partition plate (18) and the bottom surface of the container main body (11) communicates with the air flow path (19a).

(21) An outlet (18b) is formed at the floorboard (19) facing the front of the container main body (11) (on the right side in FIG. 2). The outlet (18b) blows air treated in the container refrigerator (10) (that is, internal air cooled) into the cargo storage space (S3) of the container main body (11).

(22) As shown in FIG. 3, the container refrigerator (10) is provided with a refrigerant circuit (20), in which refrigerant is circulated so that a vapor compression refrigeration cycle is carried out. The refrigerant circuit (20) includes a compressor (21), a condenser (22), an expansion valve (23) and an evaporator (24) which are connected in series with a refrigerant pipe (28).

(23) As shown in FIG. 1 and FIG. 2, the compressor (21) and the condenser (external heat exchanger) (22) are housed in the external storage space (S1). An external fan (25) is disposed above the condenser (22). The external fan (25) is driven in rotation by an external fan motor (25a) and guides air found outside of the container main body (11) into the external storage space (S1) and sends it to the condenser (22). In the condenser (22), heat is exchanged between a refrigerant flowing inside the condenser (22) and outside air.

(24) The evaporator (24) is stored in the internal storage space (S2). As shown in FIG. 5, two internal fans (26) adjacent to each other in a width direction of the casing (12) are disposed above the evaporator (24) in the internal storage space (S2). A drain pan (27) receiving drain water generated in the evaporator (24) is provided in the bottom part of the internal storage space (S2), as shown in FIG. 5. The drain pan (27) has an inclined surface whose height decreases in the direction from either end of the casing (12) toward the center of the casing (12).

(25) The internal fan (26) is driven in rotation by an internal fan motor (26a), guides internal air of the container main body (11) from the intake port (18a), and blows the air to the evaporator (24). In the evaporator (24), heat is exchanged between a refrigerant flowing inside the evaporator (24) and internal air. Internal air cooled through heat discharge to refrigerant at the time of passing through the evaporator (24) passes through the air flow path (19a) and is blown from the outlet (18b) into the cargo storage space (S3) of the container main body (11).

(26) The container refrigerator (10) includes a mixed gas supply device (30) which supplies mixed gas with a low oxygen concentration to the cargo storage space (S3) of the container main body (11) to adjust oxygen concentration in the internal spaces (S2, S3). The mixed gas supply device (30) is unitized and disposed at the lower left corner of the external storage space (S1), as shown in FIG. 1. On the right side of the mixed gas supply device (30), there is disposed an inverter box (29) which houses a driver circuit driving the compressor (21) at a variable velocity.

(27) The container refrigerator (10) includes a sensor for refrigerant leakage detection (35) detecting refrigerant leakage from the refrigerant circuit (20). The sensor for refrigerant leakage detection (35) is disposed outside of the internal spaces (S2, S3) of the container main body (11). Specifically, the above sensor for refrigerant leakage detection (35) is disposed at least partially outside of the storage box with respect to the thermal insulator (12c) disposed in the casing (12). In other words, the sensor for refrigerant leakage detection (35) is disposed between the interior wall (12b) and the exterior wall (12a). The thermal insulator (12c) is disposed between the refrigerant detection sensor (35) and the interior wall (12b) (at the side of the internal spaces (S2, S3) facing the sensor for refrigerant leakage detection (35)). A door (12d) for maintenance of the sensor for refrigerant leakage detection (35) is provided on the exterior wall (12a). Further, the sensor for refrigerant leakage detection (35) may be disposed in the external storage space (S1), as indicated by an imaginary outline in FIG. 2.

(28) Between the interior wall (12b) and the exterior wall (12a), there is provided an air tube serving as an internal air guide passage (36) guiding internal air from the discharge side of the internal fan (26) disposed in the internal storage space (S2) of the container main body (11) to the sensor for refrigerant leakage detection (35). An air-inlet side end (36a) of the internal air guide passage (36) is disposed on the discharge side of the internal fan (26) and an air-outlet side end (36b) of the internal air guide passage (36) is disposed at the intake side of the internal fan (26). The air-inlet side end (36a) of the internal air guide passage (36) is disposed downstream of airflow of the evaporator (24), that is, below the evaporator (24) viewed in a height direction.

(29) The interior wall (12b) of the casing (12) is provided with a plurality of plates (ribs) (12e) extending in a vertical direction. The interior wall (12b) is provided with a guide member (37), which is disposed between the plates (12e) and guides air flowing through the cargo storage space (S3) of the container main body (11) into the internal air guide passage (36). In other words, this guide member (37) is disposed at the side of the internal wall (12b) facing the cargo storage space (S3) in the container main body (11). Each plate (37) has an opening (120 through which air flowing along the guide member (37) passes, as shown in FIG. 6.

Operation

(30) During operation of the container refrigerator (10) of this embodiment, the compressor (21) of the refrigerant circuit (20) is started so that the refrigeration cycle is performed in the refrigerant circuit (20). Air in the internal storage space (S2, S3) is circulated between the cargo storage space (S3) and the internal storage space (S2) by the internal fan (26), and is cooled while passing through the evaporator (24) due to heat absorption by the refrigerant. The refrigerant circulates in the refrigerant circuit (20), absorbs heat in the evaporator (24) from internal air, and evaporates; whereas, the refrigerant repeats the cycle of discharging heat to external air and condensing in the condenser (22).

(31) The internal air flowing in the internal storage space (S2) flows partially from the air-inlet side end (36a) into the internal air guide passage (36). The internal air flowing into the internal air guide passage (36) passes through the sensor for refrigerant leakage detection (35) and then flows out from the air-outlet side end (36b), returning to the internal storage space (S2). Since internal air passes through the sensor for refrigerant leakage detection (35), refrigerant leakage is detected by the sensor for refrigerant leakage detection (35) in case where the refrigerant leaks out from the refrigerant circuit.

(32) The above sensor for refrigerant leakage detection (35) is disposed at the position distant from the internal spaces (S2, S3) with the thermal insulator (12c) interposed therebetween. As a result, the sensor for refrigerant leakage detection (35) is less likely to be affected by the temperature in the internal spaces (S2, S3). Hence, the sensor for refrigerant leakage detection (35) is less subject to dew condensation even in case of low temperature in the internal spaces (S2, S3).

Advantages of Embodiment

(33) According to this embodiment, the sensor for refrigerant leakage detection (35) is disposed outside of the internal spaces (S2, S3) and the thermal insulator (12c) is interposed between the sensor for refrigerant leakage detection (35) and the internal spaces (S2, S3). Therefore, refrigerant leakage can be detected without taking any measure of heating up the sensor for refrigerant leakage detection (35) even in case of low temperature. Therefore, dew condensation of the sensor for refrigerant leakage detection (35) can be prevented, resulting in prevention of breakdown of the sensor for refrigerant leakage detection (35).

(34) According to this embodiment, the sensor for refrigerant leakage detection (35) is disposed not inside, but outside of, the internal spaces (S2, S3). Therefore, the sensor for refrigerant leakage detection (35) may be replaced or repaired in case of breakdown. In particular, according to this embodiment, the door (12d) for maintenance is provided in the casing (12) so that the maintenance of the sensor for refrigerant leakage detection (35) can easily be carried out. Conventionally, with the sensor for refrigerant leakage detection broken down, cargoes have to be transported while the situation inside the container main body (11) is unclear. As a result, at the time of unloading cargoes upon arrival, the measure to prevent the combustible refrigerant from flowing out from the internal spaces (S2, S3) of the container main body (11) to the outside irrespective of the existence of refrigerant leakage is required. On the other hand, according to this embodiment, the situation inside the container main body (11) can be clearly understood, eliminating the unnecessary countermeasure to refrigerant leakage at the time of unloading cargoes.

(35) According to this embodiment, the air-inlet side end (36a) of the internal air guide passage (36) is disposed at the discharge side of the internal fan (26). This air-inlet side end (36a) of the internal air guide passage (36) is disposed downstream in the flow direction of internal air with respect to the evaporator (24), that is, below the evaporator (24) in a height direction. As a result, it is ensured that internal air partially passes through the sensor for refrigerant leakage detection (35). Therefore, the detection accuracy can be enhanced. The guide member (37) is disposed, in the casing (12), facing the internal spaces (S2, S3) and guides internal air into the air-inlet side end (36a) of the internal air guide passage (36), which also leads to the enhancement of the detection accuracy of the refrigerant detection leakage sensor (35).

VARIATIONS OF EMBODIMENT

First Variation

(36) FIG. 7 and FIG. 8 show a first variation of the embodiment. This first variation is an example in which the position of the sensor for refrigerant leakage detection (35) is different from that of the embodiment shown in FIG. 1 to FIG. 6.

(37) In this first variation, the sensor for refrigerant leakage detection (35) is disposed at a position behind the external fan (25) shown in FIG. 7. Except for this point, the configuration of this variation is similar to that of the above embodiment, including the structure where the sensor for refrigerant leakage detection (35) is disposed between the exterior wall (12a) and the interior wall (12b) of the casing (12).

(38) Also in this first variation, air can be surely guided from the internal spaces (S2, S3) to the sensor for refrigerant leakage detection (35), as in the case of the embodiment shown in FIG. 1 to FIG. 6. As a result, refrigerant leakage can be detected with high accuracy, eliminating the unnecessary countermeasure to refrigerant leakage at the time of unloading cargoes. Further, the sensor for refrigerant leakage detection (35) is less likely to be affected by the temperature in the internal spaces (S2, S3) and thus less subject to dew condensation. This almost saves the need for the countermeasure to the breakdown of the sensor for refrigerant leakage detection (35) and facilitates the replacement or repair in case of breakdown.

Second Variation

(39) FIG. 9 and FIG. 10 show a second variation of the embodiment. This second variation is an example in which the position of the sensor for refrigerant leakage detection (35) is different from that of the embodiment shown in FIG. 1 to FIG. 6 as well as that of the first variation shown in FIG. 7 and FIG. 8.

(40) In this second variation, the sensor for refrigerant leakage detection (35) is disposed in the vicinity of the outlet of a ventilation port (11a) disposed in the casing (12) of the container main body (11). Further, the sensor for refrigerant leakage detection (35) is disposed outside the casing (12). An air-inlet side end (36a) for internal air of the internal air guide passage (36) is disposed inside the ventilation port (11a) and the air-outlet side end (36b) is disposed below the sensor for refrigerant leakage detection (35).

(41) Also with this configuration, air can be surely guided from the internal spaces (S2, S3) to the sensor for refrigerant leakage detection (35). As a result, refrigerant leakage can be detected, eliminating the unnecessary countermeasure to refrigerant leakage at the time of unloading cargoes. Further, the sensor for refrigerant leakage detection (35) is less likely to be affected by the temperature in the internal spaces (S2, S3) and thus less subject to dew condensation. This almost saves the need for the countermeasure to the breakdown of the sensor for refrigerant leakage detection (35) and facilitates the replacement or repair in case of breakdown. Further, in this configuration of the second variation, the sensor for refrigerant leakage detection (35) can be easily disposed. It is also possible to retrofit the sensor for refrigerant leakage detection (35) to the container refrigerator (10).

Third Variation

(42) The sensor for refrigerant leakage detection (35) may be disposed at a position indicated by the imaginary outline of FIG. 2. In this third variation, the sensor for refrigerant leakage detection (35) is disposed inside the external storage space (S1) of the casing (12) and downstream of the air flow in the condenser (22). The position of the air tube, that is, the internal air guide passage (36) may appropriately be positioned in accordance with the position of the sensor for refrigerant leakage detection (35).

(43) With this configuration, warm air after passing through the condenser (22) passes through the sensor for refrigerant leakage detection (35). As a result, the sensor for refrigerant leakage detection (35) is less subject to dew condensation than in the above embodiment or the variations. Furthermore, the measure to the breakdown of the sensor for refrigerant leakage detection (35) can easily be taken, eliminating the unnecessary countermeasure to refrigerant leakage at the time of unloading cargoes.

Other Embodiments

(44) The above-described embodiment may be modified as follows.

(45) In the above embodiment or the variations, the sensor for refrigerant leakage detection (35) is disposed between the exterior wall (12a) and the interior wall (12b), in the external storage space (S1), or bellow the ventilation port (11a) of the casing (12). The position of the sensor for refrigerant leakage detection (35) may be appropriately changed as long as it is disposed outside the internal spaces (S2, S3) of the container main body (11) and internal air can be guided through the internal air guide passage (36).

(46) Further, according to the embodiment, the container refrigerator (10) cooling the inside of the container main body (11) is described. This disclosure is not limited to the container refrigerator (10) used for marine transportation or land transportation, but applicable for a refrigerator adjusting the temperature and the humidity in the internal spaces of various storage boxes including land-based warehouses storing various goods.

INDUSTRIAL APPLICABILITY

(47) As described above, this disclosure is useful for the refrigerator provided with the sensor for refrigerant leakage detection detecting refrigerant leakage in the refrigerant circuit.

DESCRIPTION OF REFERENCE CHARACTERS

(48) 10 Container Refrigerator (Refrigerator) 11 Container Main Body (Storage Box) 11a Ventilation Port 12 Casing 12c Thermal Insulator 20 Refrigerant Circuit 22 Condenser 24 Evaporator 26 Internal Fan (Fan) 35 Sensor for Refrigerant Leakage Detection 36 Internal Air Guide Passage 36a Air-inlet Side End 36b Air-outlet Side End 37 Guide Member