JP2007218537A - Refrigerating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating apparatus, capable of preventing freezing clogging of a drain passage 3b without using an electric heater H. <P>SOLUTION: A refrigerant pipe 15 for carrying hot gas to be distributed to a drain pan heater 15a is disposed within the drain passage 3b guiding condensed water from a drain pan 20 out of a freezing chamber 2. Since the drain passage 3b is warmed by the refrigerant pipe 15 guiding the hot gas to the drain pan heater 15a at the time of defrosting, the freezing clogging of the drain passage 3b can be prevented without using the electric heater. The structure of the refrigerating apparatus can be simplified to suppress the cost. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus that performs hot gas defrosting.

  6A is a side cross-sectional structure diagram of a conventional cooling unit 3, FIG. 6B is a F view in FIG. 6A, and FIG. 6C is a G view in FIG. Conventionally, frost adhering to the evaporator (cooling heat exchanger) 11 and the drain pan (condensate receiver) 20 of the refrigeration apparatus is obtained by flowing hot gas discharged from the compressor to the drain pan heater (drain pan defrosting pipe) 15a. After that, a hot gas defrosting method is generally adopted in which the frost that flows to the evaporator 11 and melts the frost attached to both is used.

  In addition, an electric heater H is disposed in the drainage passage 3b so that the water that has melted the frost is not frozen in the drainage passage 3b, and is energized at the same time as the defrosting operation to prevent freezing clogging. Note that reference numerals not described in FIG. 6 correspond to reference numerals described in the embodiments of the present invention described later, and thus description thereof is omitted here.

  However, the conventional structure has a problem that the cost of the refrigeration apparatus increases because an expensive electric heater is used. The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a refrigeration apparatus capable of preventing the drainage passage from being frozen and clogged without using an electric heater.

In order to achieve the above object, the present invention employs technical means described in claims 1 to 3. That is, in the invention described in claim 1, the compressor (7), the condenser (8), the pressure reducing means (10), and the evaporator (11) are connected to the evaporator (11). 11) is a refrigeration apparatus for cooling the inside of the freezer compartment (2),
A drain pan (20) collecting and collecting condensed water generated from the evaporator (11);
A defrosting bypass circuit (BP) for supplying hot gas discharged from the compressor (7) to the evaporator (11) by bypassing the condenser (8) and the decompression means (10);
In a refrigeration apparatus provided with a drain pan heater (15a) that is provided in a defrosting bypass circuit (BP) and heats the drain pan (20) with hot gas,
The refrigerant pipe (15) through which the hot gas flowing through the drain pan heater (15a) flows is disposed in the drainage passage (3b) for guiding the condensed water from the drain pan (20) to the outside of the freezer compartment (2). Yes.

  According to the first aspect of the present invention, at the time of defrosting, since the drainage passage (3b) is warmed by the refrigerant pipe (15) through which the hot gas flows through the drain pan heater (15a), an electric heater is used. The freezing clogging of the drainage passage (3b) can be prevented without this. Further, the configuration of the refrigeration apparatus can be simplified, and the cost can be suppressed.

Moreover, in invention of Claim 2, in the refrigeration apparatus of Claim 1, it is equipped with the drain hose (21) connected to the drainage passage (3b) and discharging condensed water out of the freezer compartment (2). In
It is characterized in that at least a portion of the drain hose (21) in the freezer compartment (2) is heated by the refrigerant pipe (15).

  The portion of the drain hose (21) that is in the freezer compartment (2) may also be cooled and cause clogging, but according to the invention described in claim 2, similarly to the drainage passage (3b). Since at least a portion of the drain hose (21) in the freezer compartment (2) is warmed by the refrigerant pipe (15) at the time of defrosting, freezing clogging can be prevented.

  The invention according to claim 3 is characterized in that, in the refrigeration apparatus according to claim 1 or 2, the refrigeration apparatus is used for a refrigeration apparatus of a refrigeration vehicle. According to the third aspect of the present invention, it is possible to provide a refrigeration vehicle that does not cause poor drainage due to freezing clogging. Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with the specific means described in the embodiments described later.

(Embodiment)
Hereinafter, embodiments of the present invention (application of claims 1 to 3) will be described in detail with reference to FIGS. FIG. 1 is a perspective view showing a schematic configuration of a refrigeration vehicle refrigeration apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a configuration on a refrigeration cycle in the refrigeration apparatus of FIG. . 3A is a side cross-sectional structure diagram of the cooling unit 3 according to an embodiment of the present invention, FIG. 3B is a view as viewed from A in FIG. 3A, and FIG. FIG.

  In the present embodiment, as shown in FIG. 1, the refrigeration apparatus 1 for a refrigeration vehicle is described as being mounted on a truck type refrigeration vehicle. The truck bed is provided with a freezer compartment (freezer) 2 in which a frozen product such as frozen food is loaded. Further, behind the freezer compartment 2, a loading / unloading door 4 is provided for loading the frozen matter into the freezer compartment 2 or carrying the frozen matter in the freezer compartment.

  As shown in FIG. 2, the refrigeration cycle is a well-known one comprising a compressor 7, a condenser 8, a receiver 9, a decompression means 10, an evaporator 11, an accumulator 12, and a refrigerant pipe connecting them. First, the compressor 7 sucks the gas-phase refrigerant and compresses it to a high temperature and a high pressure, and is driven by a vehicle travel engine (not shown).

  The compressor 7 is switched so as to be selectively driven or stopped by a known electromagnetic clutch 7a which is a driving force interrupting means. The electromagnetic clutch 7a transmits the driving force of the traveling engine to the compressor 7 when energized, and interrupts the driving force from the traveling engine when the energization is interrupted.

  The condenser 8 condenses the refrigerant discharged from the compressor 7 and is installed standing on the lower side of the vehicle. The internal refrigerant is cooled and condensed by the cooling air blown by the cooling fan 8a. The The receiver 9 separates the refrigerant condensed in the condenser 8 into a gas-phase refrigerant and a liquid-phase refrigerant and stores and discharges the liquid-phase refrigerant.

  The expansion valve 10 serving as a decompression unit decompresses the liquid phase refrigerant from the receiver 9. The expansion valve 10 is a temperature-operated expansion valve having a temperature sensing unit (not shown) that detects the outlet refrigerant temperature of the evaporator 11, and is opened so as to maintain the degree of superheat of the outlet refrigerant of the evaporator 11 at a predetermined position. The degree (refrigerant flow rate) is adjusted.

  The evaporator 11 is a heat exchanger that heats and evaporates the refrigerant decompressed by the expansion valve 10 with the air in the freezer compartment 2 circulated by the refrigeration fan 11a, and cools the circulating air by the latent heat of evaporation. . The accumulator 12 separates the refrigerant that has passed through the evaporator 11 into a gas phase refrigerant and a liquid phase refrigerant, and leads the gas phase refrigerant to the compressor 7 while storing the liquid phase refrigerant.

  A cooling unit 3 is attached above the vehicle front side in the freezer compartment 2 with a hole formed in the outer wall heat insulation panel 2a of the freezer 2 (see FIG. 3A). The cooling unit 3 mainly includes the previous refrigeration fans 11a (two in this embodiment) and the previous evaporator 11 in a heat insulating case 3a serving as an air passage.

  The refrigeration fan 11a sucks air in the freezer compartment 2 from the lower surface side of the heat insulation case 3a, passes through the evaporator 11 and cools, and then blows air into the freezer compartment 2 from the vehicle rear side surface of the heat insulation case 3a. It has become. The refrigeration fan 11a blows the cooling air cooled by the evaporator 11 throughout the freezer compartment 2 so that the inside of the freezer compartment 2 has a uniform temperature distribution.

  Further, below the evaporator 11, a drain pan 20 that receives and collects condensed water generated from the evaporator 11 is provided. The condensed water collected in the drain pan 20 is connected to the drainage passage 3b through drainage passages 3b (in this embodiment, two on the left and right sides of the vehicle, see FIG. 3) provided on the inner lower surface of the heat insulation case 3a. It goes out of the freezer compartment 2 through the drain hose 21 and is drained under the vehicle floor (see FIG. 1).

  Further, in the refrigeration cycle in the present embodiment, a defrosting bypass that leads hot gas by communicating the discharge side (P1) of the compressor 7 with the downstream side of the expansion valve 10 and the upstream side (P2) of the evaporator 11. A circuit BP is provided (see FIG. 2). The defrosting bypass circuit BP is provided with an electromagnetic valve 16 as an opening / closing means.

  A part of the refrigerant pipe 15 forming the defrosting bypass circuit BP also serves as a drain pan heater 15a for heating the drain pan 20 during hot gas defrosting, and is installed so as to fold the inner surface of the drain pan 20. (See FIG. 3). As a feature of the present embodiment, the refrigerant pipe 15 that guides the hot gas to the drain pan heater 15a passes through the drainage passage 3b.

  Further, in the drainage passage 3b on the other end side, a pipe portion 15b obtained by extending a part of the drain pan heater 15a passes through the drainage passage 3b. This is because, during the hot gas defrosting described later, while the frost melted in the evaporator 11 and the drain pan 20 becomes water and flows in the drain passage 3b, it freezes on the cold heat insulating case 3a and causes freezing clogging. The drainage passage 3b is also heated at the same time in the piping portion through which hot gas flows.

  Moreover, as a part which may raise | generate a freezing clogging, there exists a part which has passed in the freezer compartment 2 among the drain hoses 21 connected to this drainage passage 3b (C section in Fig.3 (a)). . FIG. 4 is a perspective view showing a structure of a portion C in FIG. As shown in FIG. 4, in this embodiment, the drain hose 21 passing through the inside of the freezer compartment 2 is entangled with the refrigerant pipe 15 and covered with a heat insulating member 24 such as urethane. The drain hose 21 is warmed so as not to occur.

  Incidentally, on the side warmed by the piping portion 15 b, the piping portion 15 b has a length protruding from the tip end heat insulating case 3 a so as to enter the drain hose 21, and the protruding piping portion 15 b is inserted into the drain hose 21. In addition, the outer surface of the drain hose 21 is covered with a heat insulating member 24.

  The control device 6 includes computer means such as a microcomputer, and performs arithmetic processing based on an input signal from an input terminal to control the refrigeration cycle. The control device 6 is connected to a temperature setter 22 that sets a set temperature in the freezer compartment 2 as an input signal and a freezing start switch 23 that starts freezing in the freezer compartment 2.

  The temperature setter 22 is configured by, for example, a variable resistor, and the set temperature can be arbitrarily changed within a range of, for example, −10 ° C. to −20 ° C. On the other hand, the energizing circuit of the electromagnetic clutch 7a, the cooling fan 8a, the refrigeration fan 11a, and the electromagnetic valve 16 are connected to the control device 6 as output signals.

  Next, the outline | summary of the action | operation in the freezing apparatus of the said structure is demonstrated. The control device 6 is supplied with electric power when a vehicle ignition switch (not shown) is turned on. When the refrigeration start switch 23 is turned on (a signal for cooling the freezer compartment 2 is generated) in a state where the ignition switch is turned on, the temperature in the freezer compartment 2 is changed by the control device 6 to the above temperature. It is automatically controlled so as to be a set temperature (for example, -20 ° C.) set by the setting device 22.

  More specifically, when the refrigeration start switch 23 is turned on, the control device 6 energizes the electromagnetic clutch 7a and connects the vehicle running engine and the compressor 7 to drive the compressor 7 (ON). To do. At this time, the control device 6 starts cooling the freezer compartment 2 by operating (ON) the cooling fan 8a and the freezing fan 11a.

  Thereafter, when the freezer temperature detected by a freezer temperature sensor (not shown) reaches the set temperature (−20 ° C.), the electromagnetic clutch 7 a is cut off, and the vehicle running engine and the compressor 7 are connected. Is shut off (OFF), and the cooling fan 8a and the refrigeration fan 11a are stopped (OFF).

  For example, when the temperature in the freezer compartment 2 is slightly higher than the set temperature and becomes −18 ° C., the compressor 7 is driven as described above, and the cooling fan 8a and the freezing fan 11a are operated. The electromagnetic valve 16 is in a closed state (OFF) except when hot gas defrosting described later is performed.

  By the way, in the freezer car as mentioned above, since the temperature in the freezer compartment 2 is extremely low, such as −20 ° C., frost adheres to the evaporator 11, and the cooling capacity of the evaporator 11 decreases. End up. Therefore, in the refrigerator, defrost control for removing frost attached to the evaporator 11 is performed. And in this embodiment, the following hot gas defrost operation is performed by the control apparatus 6 as defrost control.

  When the refrigeration start switch 23 is turned on with the ignition switch turned on, the refrigeration operation is started and a timer in the control device 6 is started, and when a predetermined time (3 hours in the present embodiment) elapses. Hot gas defrosting operation is started. Specifically, the solenoid valve 16 is opened (ON) while the electromagnetic clutch 7a remains on, and the high-temperature and high-pressure gas-phase refrigerant (hot gas) is passed through the defrosting bypass circuit BP. Directly flow to the evaporator 11.

  Then, the cooling fan 8a and the freezing fan 11a are stopped. Thereby, the frost adhering to the evaporator 11 is melt | dissolved with the heat | fever of hot gas, and a defrost is performed effectively. At this time, the drain pan 20, the drainage passage 3 b, and the drain hose 21 are also warmed together by the refrigerant pipes 15, 15 a, and 15 b through which hot gas flows.

  Subsequently, it is determined whether or not to end the hot gas defrosting. Specifically, the hot gas defrosting is terminated when the temperature detected by a defrosting release sensor (not shown) is higher than a predetermined temperature (3 ° C. in the present embodiment). In addition, when hot gas defrosting is performed, naturally frost melts sequentially from the refrigerant | coolant upstream side of the evaporator 11. FIG.

  Therefore, in the present embodiment, the defrost release sensor is installed on the downstream side of the evaporator 11, and the hot gas defrosting can be finished when the frost attached to the evaporator 11 is completely melted. That is, when the detection temperature of the defrost release sensor (pipe temperature immediately downstream of the evaporator 11) is higher than 3 ° C., it is determined that the frost attached to the evaporator 11 has been completely removed.

  When the condition for ending the hot gas defrosting is reached, the electromagnetic clutch 7a is once turned off and the electromagnetic valve 16 is closed (OFF). Then, with the refrigeration fan 11a stopped, the electromagnetic clutch 7a and the cooling fan 8a are turned on to start the refrigeration cycle, and a precooling operation is performed. And if the evaporator 11 will be in the state which can take out cold wind below predetermined temperature, the freezing fan 11a will be turned ON and refrigerating operation will be restarted. At this time, the timer for measuring a predetermined time until the next defrosting operation is reset and restarted.

  Next, features and effects of this embodiment will be described. First, a refrigerant pipe 15 through which hot gas flows through the drain pan heater 15a is disposed in a drainage passage 3b that guides condensed water from the drain pan 20 to the outside of the freezer compartment 2. According to this, at the time of defrosting, the drainage passage 3b is warmed by the refrigerant pipe 15 that guides the hot gas to the drain pan heater 15a. Therefore, the freezing clogging of the drainage passage 3b can be prevented without using an electric heater. Further, the configuration of the refrigeration apparatus can be simplified, and the cost can be suppressed.

  Moreover, in the thing provided with the drain hose 21 which is connected to the drainage passage 3b and discharges condensed water to the outside of the freezer compartment 2, at least a portion of the drain hose 21 which is in the freezer compartment 2 is heated by the refrigerant pipe 15. Yes. The portion of the drain hose 21 that is inside the freezer compartment 2 may also be cooled and cause clogging, but according to this, at least the portion of the drain hose 21 that is inside the freezer compartment 2 is the same as the drainage passage 3b. Since it is warmed by the refrigerant pipe 15 at the time of defrosting, freezing clogging can be prevented. Moreover, this refrigeration apparatus is used for the refrigeration apparatus of a refrigeration vehicle. According to this, it can be set as the refrigerator car which does not cause the drainage failure by freezing clogging.

(Modification)
FIG. 5A is a side cross-sectional structure diagram of the cooling unit 3 in a modification of the above embodiment, FIG. 5B is a view as viewed from D in FIG. 5A, and FIG. FIG. The difference from the above-described embodiment is that the drainage passage 3b / drain hose 21 on one side is warmed by the refrigerant pipe 15 and the drainage passage 3b / drain hose 21 on the other side is warmed using the electric heater H. In this way, not all the portions are heated only by the refrigerant pipe 15, but a configuration in which other heating means is used together may be employed.

(Other embodiments)
In the above-described embodiment, the example in which the refrigeration apparatus of the present invention is applied to a refrigeration vehicle has been described. However, the present invention is not limited to the above-described embodiment, and may be applied to, for example, a stationary refrigeration apparatus. . In the above-described embodiment, the refrigerant pipe 15 on the upstream side of the drain pan heater 15a is used to heat the drain passage 3b and the drain hose 21, but the refrigerant pipe on the downstream side of the drain pan heater 15a may be used. May be divided and used for the drain pan heater 15a, the drainage passage 3b and the drain hose 21 for heating (further, for the right and for the left, etc.).

1 is a perspective view showing a schematic configuration of a refrigeration vehicle refrigeration apparatus 1 according to an embodiment of the present invention. It is a schematic diagram which shows the structure on the refrigerating cycle in the freezing apparatus of FIG. (A) is a side sectional structure figure of cooling unit 3 in one embodiment of the present invention, (b) is an A view in (a), (c) is a B view in (b). . It is a perspective view which shows the structure of the C section in Fig.3 (a). (A) is side surface sectional drawing of the cooling unit 3 in the modification of embodiment, (b) is D view in (a), (c) is E view in (b). (A) is a side sectional structure figure of the conventional cooling unit 3, (b) is F view in (a), (c) is G view in (b).

Explanation of symbols

2 ... Freezing room 3a ... Drainage passage 7 ... Compressor 8 ... Condenser 10 ... Expansion valve (pressure reduction means)
DESCRIPTION OF SYMBOLS 11 ... Evaporator 15 ... Refrigerant piping 15a ... Drain pan heater 20 ... Drain pan 21 ... Drain hose BP ... Bypass circuit for defrosting

Claims (3)

A compressor (7), a condenser (8), a decompression means (10), and an evaporator (11) are connected in an annular shape, and the evaporator (11) contains a freezing chamber (2). A refrigeration system for cooling
A drain pan (20) that receives and collects the condensed water generated from the evaporator (11);
A defrosting bypass circuit (BP) for supplying hot gas discharged from the compressor (7) to the evaporator (11) by bypassing the condenser (8) and the decompression means (10);
In a refrigeration apparatus provided with a drain pan heater (15a) provided in the defrost bypass circuit (BP) and heating the drain pan (20) with the hot gas,
A refrigerant pipe (15) through which the hot gas flowing through the drain pan heater (15a) flows is disposed in a drainage passage (3b) that guides the condensed water from the drain pan (20) to the outside of the freezer compartment (2). A refrigeration apparatus characterized by that. In what is provided with a drain hose (21) connected to the drainage passage (3b) and discharging the condensed water to the outside of the freezer compartment (2),
The refrigeration apparatus according to claim 1, wherein at least a portion of the drain hose (21) in the freezer compartment (2) is heated by the refrigerant pipe (15).   The refrigeration apparatus according to claim 1 or 2, wherein the refrigeration apparatus is used in a refrigeration apparatus for a refrigeration vehicle.

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