KR20090013222A - Refrigeration device - Google Patents

Abstract

A refrigeration device where a refrigeration expansion valve, a refrigeration heat exchanger, a compressor (11), and an outdoor heat exchanger are interconnected in sequence and that has a refrigerant circuit for performing a vapor compression refrigeration cycle. A suction pressure sensor (25) is attached to a suction tube (61) of the compressor (11) via heat absorption piping (90). The heat absorption piping (90) is connected to a discharge tube (64) of the compressor (11) via a heat transmission member (91).The length of the heat absorption piping (90) is set not less than a predetermined minimum length that is longer as the temperature of vapor in the refrigeration heat exchanger is lower.

Description

Freezer {REFRIGERATION DEVICE}

The present invention relates to a refrigerating device having a refrigerant circuit for performing a vapor compression refrigeration cycle, and more particularly, to a mounting structure of a suction pressure sensor for measuring the suction pressure of a compression mechanism.

DESCRIPTION OF RELATED ART Conventionally, the refrigerating apparatus provided with the refrigerant circuit which performs a refrigerating cycle, and performs refrigeration or freezing in a reservoir is known (for example, patent document 1 (Unexamined-Japanese-Patent No. 2004-353996)).

As for the refrigeration apparatus of patent document 1, a refrigeration heat exchanger for refrigeration, a low stage compressor, a high stage compressor, an outdoor heat exchanger, and a refrigeration expansion valve are connected in order. In the refrigerant circuit, the refrigerant compressed in two stages in the low stage compressor and the high stage compressor is radiated in the outdoor heat exchanger to condense and liquefy. The liquefied refrigerant expands in the refrigeration expansion valve, flows through the refrigeration cooling heat exchanger, endotherms from the air in the reservoir, and evaporates, for example, at -30 ° C to cool the inside of the reservoir to -20 ° C. The evaporated refrigerant is again sucked into the low stage compressor, and then the circulation is repeated.

[Initiation of invention]

[Problem to Solve Invention]

By the way, in the refrigeration apparatus of the said patent document 1, the suction pressure sensor for measuring the suction pressure of this compressor is attached to the suction pipe of a low stage side and a high stage side compressor.

Specifically, as shown in FIG. 5, a tubular pipe is connected to the compressor suction pipe a, and a male screw for connecting the pressure sensor b is formed on the outer peripheral surface at the end of the tubular pipe c. On the other hand, the pressure sensor b is provided with the connection part d in which the internal thread was formed in the inner peripheral surface, and is connected to the suction pipe a by coupling the female thread of this connection part d to the male screw of the capillary c.

Therefore, in the refrigerating device, when the evaporation temperature in the cooling heat exchanger is 0 ° C. or less, and the refrigerant below 0 ° C. flows through the suction pipe (a), it enters into a gap between the screws of the pressure sensor (b) and the custom pipe (c). One minute of freezing may cause the connection part d of the sensor b to freeze-break.

Therefore, conventionally, measures have been taken to fill the gaps between the screws with silicon to prevent moisture intrusion. However, since it takes a long time to dry the silicon, there is a problem that the workability at the time of mounting and the charge state of the silicon is non-uniform, the reliability is lowered.

In addition, instead of coupling the pressure sensor (b) to the capillary (c), there is also a method of mounting by soldering. In this method, however, it is necessary to recover the coolant at the time of replacement of the sensor b, and thus there is a problem that maintenance inspection is cumbersome.

As described above, the conventional freeze destruction prevention measures are not sufficient in terms of workability and reliability.

SUMMARY OF THE INVENTION The present invention has been made in view of this point, and in the refrigerating device having a suction pressure sensor for measuring the suction pressure of the compression mechanism, the workability is improved when the pressure sensor is attached and replaced, It aims at improving the reliability of a sensor.

[Means for solving the problem]

The first invention includes a refrigerant circuit (10) in which evaporators (16, 17), a compression mechanism (11), a condenser (13), and expansion mechanisms (15a, 15b) are sequentially connected. A refrigeration apparatus having a suction pressure sensor 25 for measuring a suction pressure of), wherein the suction pressure sensor 25 is connected to a suction pressure sensor 25 at a suction pipe 61 of the compression mechanism 11. It connects through the heat absorption piping 90 for raising the temperature of 25b more than the temperature of the suction pipe 61.

In the first invention, since the refrigerant flowing through the evaporators 16 and 17 flows through the suction pipe 61, when the set temperature of the evaporators 16 and 17 is low (0 ° C. or less), the compression mechanism 11 The low temperature refrigerant of 0 degrees C or less also flows into the suction pipe 61 of this. Therefore, in this first invention, by providing the pressure sensor 25 through the heat absorbing pipe 90, it is difficult to transmit cool heat of the refrigerant flowing through the suction pipe 61 to the suction pressure sensor 25 connecting portion 25b. In addition, the endothermic pipe 90 absorbs heat from the ambient air, thereby making the connection portion 25b of the suction pressure sensor 25 at a temperature higher than 0 ° C, thereby preventing freezing of the connection portion 25b.

According to a second aspect of the present invention, in the heat absorbing pipe (90), the temperature of the suction pressure sensor (25) connection portion (25b) is such that the temperature is higher than the suction pipe (61) by the ambient temperature. Is formed.

In the second invention, the heat absorbing pipe 90 absorbs heat from the surrounding air, whereby the suction pipe 61 is gradually heated up over the suction pressure sensor 25 connecting portion 25b, and the connecting portion of the suction pressure sensor 25 is heated. Let (25b) be temperature higher than 0 degreeC.

In the second invention, in the second invention, the minimum length of the heat absorbing pipe 90 is set to a predetermined set length that becomes longer as the evaporator temperatures of the evaporators 16 and 17 decrease.

In this third invention, as the evaporation temperature of the evaporators 16 and 17 is lowered, the temperature of the refrigerant flowing through the suction pipe 61 is lowered. Therefore, the minimum length of the heat absorbing pipe 90 is increased as the evaporator 16 and 17 are lowered, so that the temperature of the refrigerant flowing through the suction pipe 61 is lowered, thereby cooling the refrigerant. This makes it difficult to transmit to the connection portion 25b of the suction pressure sensor 25. On the other hand, the area of the heat absorbing pipe 90 is increased to increase the amount of heat absorbed by the heat absorbing pipe 90 from the ambient air.

In the fourth invention, in any one of the first to third inventions, the heat absorbing pipe 90 is provided to the high pressure side pipe 64 of the refrigerant circuit 10 through the heat transfer member 91.

In this fourth invention, the heat of the high pressure side pipe 64 is transferred through the heat transfer member 91, thereby increasing the endothermic amount of the heat absorbing pipe 90 and connecting the connection portion 25b of the suction pressure sensor 25. ) Is set to a temperature higher than 0 ° C.

Here, the high pressure side piping 64 of this 4th invention means the piping through which the refrigerant | coolant which is higher than the refrigerant | coolant which flows through the suction pipe 61 flows, and the refrigerant | coolant higher than 0 degreeC flows.

In the fifth invention, in the fourth invention, the high-pressure side pipe 64 is the discharge pipe 64 of the compression mechanism 11.

The heat absorbing amount which the heat absorbing pipe 90 receives from the high pressure side pipe 64 through the heat transfer member increases as the temperature of the high pressure side pipe 64 increases. Thus, in the fifth invention, the endothermic amount of the heat absorbing pipe 90 is reliably connected by connecting the heat absorbing pipe 90 through the discharge pipe 64 and the heat transfer member 91 of the high temperature compression mechanism 11. Enlarge it.

[Effects of the Invention]

According to the first invention, the heat absorbing pipe (90) can make it difficult to transmit the cold heat of the refrigerant flowing through the suction pipe (61) to the connection portion (25b) of the suction pressure sensor (25). The piping 90 may endotherm from ambient air or the like. As a result, even when the set temperature of the evaporators 16 and 17 is low and a low temperature refrigerant of 0 degrees C or less flows in the suction pipe 61, the connection part 25b of the said suction pressure sensor 25 will be made into temperature higher than 0 degreeC. Can be. As a result, freezing damage of the suction pressure sensor 25 connecting portion 25b can be prevented, thereby improving the reliability of the suction pressure sensor 25.

Moreover, since damage can be prevented without performing silicon filling or soldering, compared with the conventional damage prevention measures, workability | operativity at the time of attachment and replacement of the suction pressure sensor 25 improves.

Further, according to the second invention, the heat absorbing pipe 90 is formed to have a length at which the temperature of the suction pressure sensor 25 connection portion 25b is raised to a temperature higher than the suction pipe 61 due to the ambient temperature. The heat absorbing pipe 90 absorbs heat from the surrounding air, and the heat absorbing pipe 90 can be gradually heated up from the suction pipe 61 over the suction pressure sensor 25 connecting portion 25b. As a result, the connection part 25b of the said suction pressure sensor 25 can be made into temperature higher than 0 degreeC.

Further, according to the third invention, since the minimum length of the heat absorbing pipe 90 is set to a predetermined set length which is lengthened as the evaporator 16 and 17 are lowered, the suction pipe 61 is set. As the temperature of the flowing coolant is lowered, it is possible to make it difficult to transmit cooling heat of the coolant to the connection portion 25b of the suction pressure sensor 25. At the same time, the area of the heat absorbing pipe 90 can be increased to increase the amount of heat absorbed by the heat absorbing pipe 90 from the ambient air. Thereby, the connection part 25b of the said suction pressure sensor 25 can be made to temperature higher than 0 degreeC reliably according to the set temperature of the evaporator 16,17.

Further, according to the fourth invention, the heat absorbing pipe 90 can absorb heat of the refrigerant circuit 10, the high pressure side pipe 64 through the heat transfer member 91, and thus the heat absorbing pipe 90 The endothermic amount of) can be increased. Thereby, the connection part 25b of the said suction pressure sensor 25 can be made into temperature higher than 0 degreeC.

Further, according to the fifth invention, the heat absorbing pipe 90 can absorb heat of the compression mechanism 11 and the discharge pipe 64 through the heat transfer member 91, so that the Since the discharge tube 64 has a high temperature, the endothermic amount of the heat absorbing pipe 90 can be reliably increased. Thereby, the connection part 25b of the said suction pressure sensor 25 can be made into temperature higher than 0 degreeC.

1 is a piping system diagram showing a refrigerant circuit of the refrigerating device according to the embodiment.

2 is a schematic perspective view showing a mounting structure of a suction pressure sensor according to the embodiment.

3 is a relationship diagram showing a relationship between an evaporation temperature and a heat absorbing pipe length of the refrigerating heat exchanger according to the embodiment.

4 is a piping system diagram showing a circulation direction of the refrigerant during the cooling operation of the refrigerating device according to the embodiment.

5 is a schematic configuration diagram showing a conventional suction pressure sensor mounting structure.

[Description of the code]

1: Refrigerating device 10: Refrigerant circuit

11 compressor (compression mechanism) 13 outdoor heat exchanger (condenser)

25: suction pressure sensor 25a: connection

61: suction pipe 64: discharge pipe (high pressure side piping)

90: heat absorbing pipe 91: heat transfer member

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing.

Embodiment of this invention is the refrigerating apparatus 1 which cools a cooling chamber as shown in FIG. 1, and is provided with the outdoor unit 2, the refrigerating unit 3, and the controller 100. As shown in FIG. The outdoor unit 2 is installed outdoors, while the refrigerating unit 3 is installed in a cooling chamber.

In the refrigerating device 1, the outdoor circuit 20 is formed in the outdoor unit 2, and the internal circuit 30 in the refrigerator is formed in the refrigerating unit 3, respectively. In the refrigerating device 1, the gas circuit side of the outdoor circuit 20 and the gas circuit side of the internal circuit 30 of the refrigerator are connected to the gas side connection pipe 22, while the liquid circuit side of the outdoor circuit 20 and the gas terminal side of the refrigerator 20 are connected to each other. The liquid end side of the circuit 30 is connected to the liquid side connection pipe 21 to form the refrigerant circuit 10 of the vapor compression refrigeration cycle.

<Outdoor unit>

The outdoor circuit 20 of the outdoor unit 2 includes a compressor 11, an outdoor heat exchanger 13, a receiver 14, an outdoor expansion valve 45, a refrigerant heat exchanger 50, and a branch expansion valve. 46 is disposed. In addition, the four-way valve 12, the liquid side closing valve 53, and the gas side closing valve 54 are disposed in the outdoor circuit 20. One end of the liquid side connecting pipe 21 is connected to the liquid side closing valve 53 and one end of the gas side connecting pipe 22 is connected to the gas side closing valve 54 in the outdoor circuit 20.

The compressor 11 is a scroll compressor, and is configured with a variable driving capacity by inverter control. One end of the suction pipe 61 is connected to the suction side of the compressor 11, and the other end of the suction pipe 61 is connected to the four-way valve 12. One end of the discharge tube 64 is connected to the discharge side of the compressor 11, and the other end of the discharge tube 64 is connected to the four-way valve 12.

The outdoor heat exchanger (13) is a cross fin fin tube type heat exchanger, and performs heat exchange between a refrigerant and outdoor air, and is configured as a condenser. One end of the outdoor heat exchanger 13 is connected to the four-way valve 12. On the other hand, the other end of the outdoor heat exchanger 13 is connected to the top of the receiver 14 via the first liquid pipe 81. The first liquid pipe 81 is provided with a check valve CV-1 that permits only the flow of refrigerant from the outdoor heat exchanger 13 to the receiver 14. One end of the second liquid pipe 82 is connected to the bottom of the receiver 14.

The refrigerant heat exchanger (50) is a plate heat exchanger, and exchanges heat between the refrigerant and the refrigerant, and includes a first flow path (50a) and a second flow path (50b). The other end of the second liquid pipe 82 is connected to the inlet side of the first flow path 50a of the refrigerant heat exchanger 50, and one end of the third liquid pipe 83 is connected to the outlet side of the first flow path 50a. The other end of the third liquid pipe 83 is connected to one end of the liquid side connecting pipe 21 via the liquid side closing valve 53. The third liquid pipe 83 is provided with a check valve CV-2 that allows only the flow of the refrigerant from the first flow path 50a toward the liquid side closing valve 53.

One end of the branch liquid pipe 84 is connected to the third liquid pipe 83 upstream of the check valve CV-2, and the other end of the branch liquid pipe 84 is connected to the second flow path 50b of the refrigerant heat exchanger 50. ) Is connected to the inlet side. In addition, a branch expansion valve 46 is provided in the branch liquid pipe 84. The branch expansion valve 46 is an electromagnetic expansion valve in which the opening degree can be freely adjusted.

The outlet side of the second flow path 50b of the refrigerant heat exchanger 50 is connected to one end of the injection tube 85. The other end of the injection pipe 85 is connected between the four-way valve 12 and the compressor 11 in the suction pipe 61.

One end of the fourth liquid pipe 88 is connected between the check valve CV-2 and the liquid side closing valve 53 in the third liquid pipe 83. The other end of the fourth liquid pipe 88 is connected between the check valve CV-1 and the receiver 14 in the first liquid pipe 81. The fourth liquid pipe 88 is provided with a check valve CV-3 that allows only the flow of the refrigerant from the third liquid pipe 83 toward the receiver 14.

One end of the fifth liquid pipe 89 is connected to the branch liquid pipe 84 between the third liquid pipe 83 and the branch expansion valve 46, and the other end of the fifth liquid pipe 89 is connected to the first liquid pipe 81. Is connected between the other end of the outdoor heat exchanger 13 and the check valve CV-1. In addition, the fifth liquid pipe 89 is provided with an outdoor expansion valve 45.

The four-way valve 12 has a first port at the discharge pipe 64, a second port at the suction pipe 61, a third port at one end of the outdoor heat exchanger 13, and a fourth port at the gas side closing valve. And 54 respectively. The four-way valve 12 includes a first state (a state indicated by a solid line in FIG. 1) in which a first port and a third port communicate with each other, and a second port and a fourth port communicate with each other, and the first port and the first port. Four ports communicate with each other, and the second port and the third port communicate with each other, and are configured to be switchable to a second state (state indicated by a dotted line in FIG. 1).

An oil separator 70 and an oil return pipe 71 are installed in the outdoor circuit 20.

The oil separator 70 is installed in the discharge pipe 64 to separate the refrigeration oil from the discharge gas of the compressor 11. One end of the first oil return pipe 71 is connected to the oil separator 70, and the other end of the first oil return pipe 71 is connected between the connection portion of the injection pipe 85 in the suction pipe 61 and the compressor 11. do. In addition, the oil return pipe 71 is provided with a capillary tube 72 for adjusting the flow rate of the refrigeration oil.

The outdoor circuit 20 is provided with various sensors 19, 23, 24, 25, 51 and pressure switches 95a, 95b. Specifically, the suction temperature sensor 24 and the suction pressure sensor 25 are sequentially arranged in the compressor 11 suction pipe 61 between the injection pipe 85 connection part and the oil return pipe 71 connection part. Although this suction pressure sensor 25 is demonstrated in detail later, as a characteristic of this invention, it is connected to the suction pipe 61 through the heat absorption piping 90. Further, a discharge pressure sensor 23 and a discharge temperature sensor 19 are arranged on the discharge side of the compressor 11. In addition, a temperature sensor 51 is disposed at the outlet side of the first flow path 50a of the refrigerant heat exchanger 50.

In addition, the outdoor unit 2 is provided with an outdoor air temperature sensor 13a and an outdoor fan 13f. Outdoor air is supplied to the outdoor heat exchanger 13 by this outdoor fan 13f.

Refrigeration unit

The refrigerator internal circuit 30 of the refrigerating unit 3 is provided with two refrigerating heat exchangers 16 and 17 and two drain pan heaters 26 and 27, respectively.

Each of the refrigerating heat exchangers (16, 17) is the same cross fin-type fin tube type heat exchanger, the heat exchange between the refrigerant and the air in the cooling chamber, it is composed of an evaporator. One end of each of the refrigerating heat exchangers 16 and 17 is connected to each of the refrigerating expansion valves 15a and 15b through a pipe. On the other hand, one end of each of the gas side branch pipes 22a and 22b is connected to the other end of each of the refrigerating heat exchangers 16 and 17, and the other ends of the gas side branch pipes 22a and 22b are joined to each other to connect the gas side. It is connected to the other end of the pipe 22.

Each of the refrigerating expansion valves 15a and 15b is an electromagnetic expansion valve configured to freely adjust the opening degree, and is constituted by an expansion mechanism. The first refrigerant temperature sensors 16b and 17b are disposed in the refrigerator heat exchangers 16 and 17, respectively, and the second refrigerant temperature sensors 18a and 18b are disposed in the other ends of the refrigerator heat exchangers 16 and 17, respectively. do. The first refrigerant temperature sensors 16b and 17b measure the refrigerant evaporation temperature in the refrigerated heat exchangers 16 and 17. The refrigeration expansion valves 15a and 15b have a predetermined temperature (for example, a temperature higher than the evaporation temperature of the refrigerant measured by the first refrigerant temperature sensors 16b and 17b during the cooling operation). For example, 5 ° C.) so that the opening degree adjustment is made.

The drain pan heaters 26 and 27 are disposed in a drain pan (not shown), and a refrigerant having a high temperature and high pressure flows to heat the drain pan, thereby preventing the drain pan from being implanted or generating ice. One end of each of the liquid side branch pipes 21a and 21b is connected to one end of each of the drain pan heaters 26 and 27, and the other end of each of the liquid side branch pipes 21a and 21b is joined to each other and the other end of the liquid side connecting pipe 21. Is connected to. On the other hand, the other end of the drain pan heaters 26 and 27 is connected to one end of the refrigeration expansion valves 15a and 15b.

In addition, the refrigerating unit 3 is provided with cooling chamber temperature sensors 16a and 16b and cooling chamber fans 16f and 17f. Air in a cooling chamber is supplied to each said refrigeration heat exchanger 16 and 17 by these cooling chamber fans 16f and 17f.

<Controller>

The controller 100 controls the cooling operation operation to maintain the cooling chamber at the set temperature by switching various valves and adjusting the opening degree of the valves arranged in the refrigerant circuit 10 and defrosting the cooling chamber. I) Control operation operation.

<Mounting structure of suction pressure sensor>

Next, the mounting structure of the suction pressure sensor 25 which is the characteristic of this invention is demonstrated in detail based on FIGS.

During the cooling operation of the refrigerating device 1, since the refrigerant evaporated in the refrigerating heat exchangers 16 and 17 flows through the suction pipe 61, the refrigerant evaporation cloud in the refrigerating heat exchangers 16 and 17 is low, and the suction pipe 61 If the temperature of the coolant flowing in the &lt; RTI ID = 0.0 &gt; Thus, as a feature of the present invention, the suction pressure sensor 25 is connected to the compressor 11 suction pipe 61 through the heat absorbing pipe 90, as shown in Figs. The pipe 90 is connected to the discharge pipe 64 of the compressor 11 by the heat transfer member 91.

That is, the endothermic pipe 90 is for raising the temperature of the suction pressure sensor 25 connection portion 25b to the temperature of the suction pipe 61.

Specifically, as shown in FIG. 2, one end of the heat absorbing pipe 90 is connected in the middle of the suction pipe 61 of the compressor 11. The heat absorbing pipe 90 is a tube diameter thinner than the suction pipe 61 and is formed to have a length of 20 cm, and is bent four times to form a compact body. The other end of the heat absorbing pipe 90 is provided with a male screw not shown in the outer peripheral portion. The suction pressure sensor 25 is composed of a sensor body 25a and a connecting portion 25b, and a female screw (not shown) is formed on the inner circumferential surface of the connecting portion 25b. The suction pressure sensor 25 is attached to the heat absorbing pipe 90 by coupling the male screw of the connecting portion 25b to the male screw of the other end of the heat absorbing pipe 90. In addition, an L-shaped port tubular pipe 90a having a gauge port 26 is connected to the other end side of the heat absorbing pipe 90.

As shown in FIG. 2, the heat transfer member 91 is formed in a plate shape having an L cross section. The one end in the lateral direction of the heat transfer member 91 is fixed to the downstream side of the oil separator 70 in the discharge pipe 64, while the other end is connected to the other end of the heat absorbing pipe 90 (suction part of the suction pressure sensor 25). It is fixed to (25b) vicinity. In addition, the lower end side of the heat transfer member 91 is fixed to the tubular pipe (90a). Here, the heat transfer member 91 also has a function as a support member for supporting the heat absorbing pipe 90.

Next, the results of the experiment on the length of the endothermic pipe 90 will be described with reference to FIG. 3.

3 is a diagram showing the relationship between the evaporation temperature of the refrigerating heat exchangers 16 and 17 and the length of the endothermic pipe 90 at which the suction pressure sensor 25 connection portion 25b is 10 ° C. In FIG. 3, the piping structure A is a structure in which the heat absorbing pipe 90 is not connected by the compressor 11, the discharge pipe 64, and the heat transfer member 91, and the piping structure B is the same as in the present embodiment. The structure which connected the heat absorbing piping 90 to the discharge pipe 64 and the heat transfer member 91 is shown.

In the piping structure (A), the endothermic piping 90 length at which the temperature of the suction pressure sensor 25 connection portion 25b becomes 10 占 폚 has an evaporation temperature of the refrigeration heat exchangers 16 and 17 at -10 占 폚. It was found that it was necessary to lengthen the evaporation temperature as the formula was cm, 48 cm at -30 ° C, and 57 cm at -40 ° C. This is because as the evaporation temperature of the refrigerating heat exchanger (16, 17) is lowered, the temperature of the refrigerant flowing through the suction pipe (61) is lowered, so that the refrigerant is less likely to be delivered by the connection (25b) of the suction pressure sensor (25). On the other hand, it is necessary to increase the area of the endothermic pipe 90 so as to increase the endothermic amount of the endothermic pipe 90 endothermic from the surrounding air.

On the other hand, in the piping structure B, the length of the endothermic pipe 90 in which the temperature of the suction pressure sensor 25 connection portion 25b is 10 ° C, the evaporation temperature of the refrigerating heat exchanger 16, 17 is -10 ° C. 10 cm, -30 ° C. to 25 cm, and -40 ° C. to 32 cm, as in piping structure A, it is necessary to lengthen the length as the evaporation temperature decreases, while at the same evaporation temperature, It was found that the length can be shorter than that of the structure (A). This is because the endothermic pipe 90 can absorb heat from the high temperature compressor 11 discharge pipe 64 through the heat transfer member 91, so that the heat absorbing pipe 90 absorbs only the ambient air. This is because the endothermic amount of 90) can be reliably increased.

Here, although the temperature of the suction pressure sensor 25 connection part 25b should just be higher than 0 degreeC at least in order not to freeze this connection part 25b, in this experiment, the length which becomes 10 degreeC was examined. This means that when the endothermic pipe 90 is set to a length such that the temperature of the connection portion 25b becomes a predetermined temperature higher than 0 ° C, the evaporation temperatures of the refrigerating heat exchangers 16 and 17 are temporarily changed due to fluctuations in the cooling load. It is because even if it falls, the temperature of the connection part 25b can be raised reliably above 0 degreeC. Thus, considering the load fluctuation of the refrigerating device 1, the minimum length of the endothermic pipe 90 is set to the length shown in FIG.

In this embodiment, since the evaporation temperature of the refrigerating heat exchangers 16 and 17 is -10 degreeC as mentioned later, in the piping structure B, it is necessary to make the endothermic piping 90 into 10 cm or more. Thus, the heat absorbing pipe 90 is formed to a length of 20 cm, which is an arbitrary length of 10 cm or more.

Operation operation

Next, the operation | movement during the cooling operation of the refrigeration apparatus 1 of this embodiment is demonstrated based on FIG.

During the cooling operation of the refrigerating device 1, as shown in FIG. 4, the four-way valve 12 of the outdoor circuit 20 is set to the first state by the control of the controller 100, and the outdoor expansion valve (45) is to be closed. In this state, the compressor 11 is operated to control the opening of the refrigerating expansion valves 15a and 15b and the branch expansion valve 46 as appropriate, and the refrigerant is circulated in the direction indicated by the solid arrows in FIG. Here, the cooling chamber set temperature in this cooling operation is set to 2 degreeC, for example.

The refrigerant discharged from the compressor (11) is sent from the discharge pipe (64) to the outdoor heat exchanger (13) through the four-way valve (12). In the outdoor heat exchanger (13), the refrigerant radiates heat to the outdoor air to condense. The refrigerant condensed in the outdoor heat exchanger (13) flows through the first liquid pipe (81), passes through the receiver (14), and flows into the second liquid pipe (82), and the first flow path (50a) of the refrigerant heat exchanger (50). Flows. The liquid refrigerant flowing through the first flow path 50a flows through the third liquid pipe 83, and part of the liquid refrigerant flows through the branch liquid pipe 84, as indicated by the dotted arrow in Fig. 4, as a branch refrigerant. The pressure is reduced in the flow in the second flow path (50b) of the refrigerant heat exchanger (50). Accordingly, the liquid refrigerant flowing through the first flow path 50a is heat-exchanged with the branch refrigerant flowing through the second flow path 50b, and is cooled to, for example, 15 ° C., and then the liquid side closing valve 53 from the third liquid pipe 83. Through the liquid-side connection pipe 21 flows into the circuit 30 in the refrigerator. In addition, the branch liquid refrigerant of the second flow path 50b is evaporated and injected into the compressor 11 and the suction pipe 61 through the injection pipe 85.

In the refrigerator circuit 30, a 15 ° C liquid refrigerant is classified into each of the liquid side branch pipes 21a and 21b and flows through each of the drain pan heaters 26 and 27, thereby preventing the drain pans 26 and 27 from being implanted. .

The liquid refrigerant flowing out of the drain pan heaters 26 and 27 is decompressed and expanded when passing through each of the refrigerating expansion valves 15a and 15b and is introduced into the refrigerating heat exchangers 16 and 17. In each of the refrigerating heat exchangers (16, 17), the refrigerant absorbs heat from the air in the cooling chamber and evaporates to an evaporation temperature of, for example, -10 占 폚. In the refrigerating unit (3), air cooled in the refrigerating heat exchangers (16, 17) is supplied into the cooling chamber, and the temperature in the cooling chamber is maintained at 2 deg.

The refrigerant flowing through each of the refrigeration heat exchangers (16, 17) flows through each of the gas side branch pipes (22a, 22b) and then merges in the gas side connection pipe (22). Thereafter, the gas refrigerant flows through the gas side connection pipe 22 and flows through the intake pipe through the four-way valve 12, and is sucked into the compressor 11 and compressed.

Here, although the refrigerant of about −10 ° C. evaporated from the refrigerating heat exchanger (16, 17) flows into the suction pipe (61), in the present invention, the suction pressure sensor (25) passes through the suction pipe (90) for the suction pipe ( 61 is connected to the heat absorbing pipe 90, the compressor 11, the discharge pipe 64, and the heat transfer member 64, so that the connection portion 25b of the suction pressure sensor 25 freezes and breaks. There is no In addition, as shown in FIG. 3, when the evaporation temperature of the refrigerating heat exchangers 16 and 17 is -23 degreeC or more, the temperature of the suction pressure sensor 25 connection part 25b will become 10 degreeC or more certainly, and it cools during cooling operation. Even if the load fluctuates, the connection part 25b can be made temperature higher than 0 degreeC reliably.

Here, the refrigerating device 1 is configured to temporarily stop the cooling operation to perform a defrosting operation. Although the operation during the defrosting operation is not shown, the four-way valve 12 is set to the second state, the refrigerating expansion valves 15a and 15b are in the expanded state, and the branch expansion valve 46 is in the fully closed state. 45) is properly controlled, and a defrosting operation in reverse cycle is performed in which the refrigerant circulates in the reverse direction as in the cooling operation.

Specifically, the discharge gas refrigerant of the compressor 11 flows through each of the refrigerating heat exchangers 16 and 17 and each of the drain fan heaters 26 and 27, and is attached to each of the refrigerating heat exchangers 16 and 17 or the drain pan. It condenses and liquefies by dissipating to the fourth liquid pipe (88) of the outdoor circuit (20). Thereafter, the refrigerant flows through the liquid side connection pipe 21 and is introduced into the outdoor circuit 20 to flow through the fourth liquid pipe 88, and flows through the receiver 14 and the first flow path 50a of the refrigerant heat exchanger 50. In addition, when the fifth liquid pipe 89 flows, the refrigerant expands in the outdoor expansion valve 45 to condense in the outdoor heat exchanger 13 and is sucked into the compressor 11.

Effect of Embodiments

The refrigeration apparatus (1), by the endothermic pipe 90, the cooling heat of the refrigerant flowing through the suction pipe 61 can be difficult to be transmitted to the suction pressure sensor (25) connection portion 25b, the endothermic The molten pipe 90 can absorb heat from the surrounding air or the discharge pipe 64. As a result, even if the −10 ° C. refrigerant evaporated in the refrigerating heat exchangers 16 and 17 flows through the suction pipe 61, the suction pressure sensor 25 connection portion 25 b can be set to a temperature higher than −0 ° C. As a result, freezing damage of the suction pressure sensor 25 connection portion 25b can be prevented, thereby improving the reliability of the suction pressure sensor 25. In addition, since damage can be prevented without performing silicon filling or soldering, workability at the time of mounting and replacing the suction pressure sensor 25 is improved as compared with the conventional damage prevention measures.

In addition, since the heat absorbing pipe 90 absorbs heat from the discharge pipe 64 of the refrigerant circuit 10 through the heat transfer member 91, the endothermic amount of the heat absorbing pipe 90 can be increased. Thereby, the said suction pressure sensor 25 connection part 25b can be made into temperature higher than 0 degreeC.

In addition, the heat absorbing pipe (90) can absorb the heat of the discharge pipe (64) of the compression mechanism (11) through the heat transfer member (91), so that the discharge pipe (64) of the compression mechanism (11) is hot. In this case, the endothermic amount of the endothermic pipe 90 can be reliably increased. Thereby, the said suction pressure sensor 25 connection part 25b can be made to temperature higher than 0 degreeC reliably.

<< other embodiment >>

About the said embodiment, you may be set as the following structures.

The refrigeration apparatus 1 of the said embodiment forms the heat absorption piping 90 to 20 cm in length, and connects the discharge pipe 64 and the heat transfer member 91, but installs the heat transfer member 91. Without forming the heat absorbing pipe 90 to a predetermined length, the freezing may be prevented. That is, even in the piping structure A which does not connect the heat absorbing piping 90 with the discharge pipe 64, as shown in FIG. 3, the length of the heat absorbing piping 90 is 20 cm or more at the evaporation temperature -10 degreeC. When the evaporation temperature is set to a predetermined set length which is longer as the evaporation temperature is lowered in the formula of -30 ° C and 48 cm or more, the connection portion 25b of the suction pressure sensor 25 can be made 10 ° C or more. Therefore, if the length of the heat absorbing pipe 90 is set to the length or more, the connection part 25b is reliably set to a temperature higher than 0 ° C. and is frozen without connecting the heat absorbing pipe 90 with the discharge pipe 64. Breakage can be prevented.

That is, the heat absorbing pipe 90 may be formed so that the temperature of the suction pressure sensor 25 connection portion 25b is longer than the suction pipe 61 due to the ambient temperature. The minimum length of the heat absorbing pipe 90 may be set to a predetermined set length which is increased as the evaporator temperatures of the evaporators 16 and 17 are lowered.

In this case, the heat absorbing pipe 90 may be provided at any position. For example, if the heat absorbing pipe 90 is provided to be located near the discharge pipe 64, the heat of the heat discharge pipe 64 is high. It is transmitted through the air, so that the endothermic amount can be increased.

In addition, in the said embodiment, the length of the heat absorbing piping 90 shown in FIG. 3 is only an example, The length of the heat absorbing piping 90, the temperature condition of the surroundings in which the heat absorbing piping 90 is provided, and heat transfer are shown. It is preferable to set suitably according to the thermal conductivity of the member 91, the temperature of the discharge tube 64 of the compressor 11, etc. In addition, when the cooling load fluctuation of the refrigerating device 1 is small and the evaporator 16 and 17 have a constant evaporation temperature, the length of the heat absorbing pipe 90 is determined by the temperature of the suction pressure sensor 25 connection portion 25b, For example, you may set to the length used as 1 degreeC.

In addition, the refrigerating device 1 of the above embodiment performs a refrigerating cycle for compressing the refrigerant in one stage, but the refrigerating apparatus has a refrigeration heat exchanger for refrigerating the cooling chamber and performs a refrigerating cycle for compressing the refrigerant in two stages. You may also In this case, since the temperature of the refrigerant flowing through the suction pipe of the low stage compressor becomes very low, a pressure sensor for measuring the pressure of the low temperature refrigerant may be attached to the suction pipe through the heat absorption pipe. The heat absorbing pipe may be connected to the high pressure side pipe of the refrigerant circuit or the discharge pipe through which the discharge refrigerant of the low stage compressor flows and the heat transfer member.

In the outdoor circuit having a high stage compressor, a refrigerating circuit in which a refrigeration heat exchanger and a low stage compressor are connected, and a refrigerating circuit having a refrigeration heat exchanger are connected in parallel, and both the high stage compressor and the low stage compressor are 0 ° C. or less. May be connected to the suction pressure sensor of each compressor suction pipe via the heat absorbing pipe.

In addition, although the refrigeration apparatus 1 of the said embodiment connects the heat absorption piping 90 with the discharge pipe 64 of a compressor, you may connect with the other high pressure side piping of the refrigerant | coolant circuit 10. FIG. Specifically, the first to third liquid pipes 81, 82, 83 are illustrated.

In addition, although the refrigeration apparatus of the said embodiment comprises the compression mechanism 11 with one compressor 11, the compression mechanism 11 may be comprised with the compressor connected in parallel.

And the above embodiments are essentially preferred examples and are not intended to limit the invention, its applications, or its scope of use.

As described above, the present invention is useful for a refrigerating device having a suction pressure sensor for measuring the suction pressure of a compression mechanism.

Claims (5)

The refrigerant circuit 10 is connected to the evaporator 16, 17, the compression mechanism 11, the condenser 13, and the expansion mechanisms 15a, 15b in turn, and the suction pressure of the compression mechanism 11 is increased. In the refrigerating device having a suction pressure sensor 25 for measuring, The suction pressure sensor 25 is a heat absorption pipe 90 for raising the temperature of the connection portion 25b of the suction pressure sensor 25 to the suction pipe 61 of the compression mechanism 11 higher than the suction pipe 61 temperature. Refrigeration apparatus characterized in that connected through). The method according to claim 1, The endothermic pipe (90) is a refrigeration apparatus, characterized in that the temperature of the connection portion (25b) of the suction pressure sensor (25) is formed in a length such that the temperature is higher than the suction pipe (61) according to the ambient temperature. The method according to claim 2, The minimum length of the heat absorbing pipe (90) is set to a predetermined set length that is lengthened as the evaporator (16, 17) evaporation temperature is lowered. The method according to claim 1, The heat absorbing pipe (90) is installed in the high pressure side pipe (64) of the refrigerant circuit (10) via a heat transfer member (91). The method according to claim 4, The high pressure side pipe (64) is a refrigeration apparatus, characterized in that the discharge pipe (64) of the compression mechanism (11).

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