JP2010002075A - Air conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning device preventing a filter from being blocked by ice particles when water mixed in a refrigerant freezes and the ice particles generate. <P>SOLUTION: In this air conditioning device 1, the filter 354 for removing foreign matter is mounted at a low pressure side of a refrigerant circuit 10. A size A of a mesh of the filter is 80 μm or more and 160 μm or less. As a result, the ice particles do not excessively accumulate on a surface of the filter 354 even when the water mixed in the refrigerant freezes and the ice particles generate, thus the filter 354 is not blocked by the ice particles, and the dust and metallic powder such as rust of particle size of 160 μm or more which is harmful for the refrigerant circuit 10, can be removed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air conditioner that cools and heats a room such as a building by vapor compression refrigeration cycle operation.

  In air conditioners that require local piping work, moisture may be mixed into the pipes during installation, and air conditioners that connect a dryer to the refrigerant circuit are widely used to remove moisture ( For example, see Patent Document 1). On the other hand, according to the experiment conducted by the applicant, it was confirmed that there is no adverse effect on the air conditioner even if a moisture removing device such as a dryer is not provided if the moisture mixed in the pipe is below a certain amount. Yes.

However, in general, the air conditioner is provided with a filter in front of the compressor inlet and in front of the expansion valve for the purpose of removing dust and rust, and when the refrigerant temperature falls below the freezing temperature of water The water freezes into ice particles, which can become clogged by the filter capturing the ice particles. Therefore, when a moisture removing device such as a dryer is not provided, it is necessary to prevent the filter from being blocked by ice particles.
JP-A-10-253179

  The subject of this invention is providing the air conditioning apparatus which prevented the filter from being obstruct | occluded with ice particles, when the water | moisture content mixed into the refrigerant | coolant frozen and ice particles generate | occur | produced.

  An air conditioner according to a first aspect of the present invention is an air conditioner in which a filter for removing foreign matter is attached to the low pressure side of a vapor compression refrigerant circuit, and the mesh of the filter is included in the refrigerant. The size is set so as not to be blocked by ice particles generated by freezing of water.

  When the water contained in the refrigerant freezes due to a decrease in the evaporation temperature, the filter net originally installed for the purpose of removing dust and the like contained in the refrigerant may be blocked by ice particles. In this air conditioner, the opening of the filter mesh is set to a size that does not cause excessive accumulation of ice particles, so that the filter is prevented from being blocked by ice particles.

  An air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect of the present invention, wherein the mesh opening of the filter is larger than 80 μm.

  In this air conditioner, since the opening of the filter mesh is set to be larger than 80 μm, the filter is prevented from being blocked due to excessive adhesion of ice particles to the filter surface.

  An air conditioner according to a third aspect of the present invention is the air conditioner according to the second aspect of the present invention, wherein the mesh opening of the filter is smaller than 160 μm.

  In this air conditioner, most of foreign matters such as iron powder contained in the refrigerant are 160 μm or more and are captured by the filter, so that each device of the refrigerant circuit is prevented from being damaged by the foreign matters.

  In the air conditioner according to the first aspect of the present invention, the opening of the filter mesh is set to a size that does not cause blockage due to ice particles, so that blockage of the filter due to ice particles is prevented.

  In the air conditioner according to the second aspect of the present invention, since the opening of the filter mesh is set to be larger than 80 μm, ice particles generated by freezing of water contained in the refrigerant do not excessively adhere to the filter surface. Therefore, the filter is prevented from being blocked by ice particles.

  In the air conditioner according to the third aspect of the invention, most of the foreign matter such as iron powder contained in the refrigerant is 160 μm or more and is captured by the filter, so that each device of the refrigerant circuit is prevented from being damaged by the foreign matter. .

  Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention.

<Indoor unit>
The indoor unit 4 is installed by being embedded or suspended in a ceiling of a room such as a building or by hanging on a wall surface of the room, and has an indoor expansion valve 41 and an indoor heat exchanger 42. The indoor expansion valve 41 is an electric expansion valve and is connected to the liquid side of the indoor heat exchanger 42. The indoor heat exchanger 42 is a cross fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of fins, and serves as a refrigerant evaporator during cooling operation to cool indoor air. During the heating operation, it becomes a refrigerant condenser and heats indoor air.

<Outdoor unit>
The outdoor unit 2 is installed outside a building or the like, and includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, and an outdoor expansion valve 35. The compressor 21 is an inverter compressor whose capacity can be changed by rotational speed control.

  The four-way switching valve 22 is a valve that switches the direction of refrigerant flow. During the cooling operation, the discharge side of the compressor 21 and the gas side of the outdoor heat exchanger 23 are connected, and the gas side of the indoor heat exchanger 42 and the suction side of the compressor 21 are connected (four-way switching in FIG. 1). (See solid line for valve 22). Further, during the heating operation, the discharge side of the compressor 21 and the gas side of the indoor heat exchanger 42 are connected, and the suction side of the compressor 21 and the gas side of the outdoor heat exchanger 23 are connected (four in FIG. 1). (Refer to the broken line of the path switching valve 22).

  The outdoor heat exchanger 23 is a cross fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of fins. The outdoor heat exchanger 23 serves as a refrigerant condenser during the cooling operation, and serves as a refrigerant evaporator during the heating operation. It becomes.

  The outdoor expansion valve 35 is an electric expansion valve, and is connected between the outdoor heat exchanger 23 and the indoor expansion valve 41 in order to adjust the pressure, flow rate, and the like of the refrigerant flowing in the refrigerant circuit 10 on the outdoor side. The

(Filter device)
The filter device 350 is disposed upstream of the suction port of the compressor 21 for the purpose of removing metal powder such as dust and rust flowing together with the refrigerant before being sucked into the compressor 21.

  FIG. 2 is a perspective view of the filter device 350. In FIG. 2, the filter device 350 includes a cylindrical container 351, a refrigerant introduction pipe 352 that guides the refrigerant to the inside of the container 351, a refrigerant outlet pipe 353 that guides the refrigerant to the outside of the container 351, and the flow direction of the refrigerant inside the container 351. And a filter 354 for partitioning to intersect. The filter 354 captures metal powder such as dust and rust that is mixed with the refrigerant and is about to pass therethrough.

  FIG. 3 is a plan view showing the opening of the filter. In FIG. 3, the opening A of the filter 354 is the length of the space existing between the line 354 a and the line 354 a constituting the net of the filter 354. Usually, in order to remove metal dust such as rust and particles having a particle diameter of 160 μm or more which is harmful to the refrigerant circuit 10, a plain weave 100 mesh having an opening A of about 154 μm or a filter thinner than that is required. Has been.

  On the other hand, if the mesh value of the filter is too large, that is, if the opening A is too small, the filter 354 may be clogged with ice particles when the temperature of the refrigerant decreases. Has been confirmed by. According to the experiment, when the amount of moisture that does not adversely affect the refrigerant circuit 10 due to the deterioration of the refrigerating machine oil is mixed and diffused in the refrigerant in the refrigerant circuit 10, the opening of the filter 354 is made too small. In this case, it was confirmed that the filter 354 was blocked or deformed by ice particles adhering to the filter 354.

  As the filter 354 of the present embodiment, a filter that allows ice particles to pass through and captures metal powder such as dust and rust and satisfies the condition of 80 μm <opening A <160 μm is employed.

<Operation of air conditioner>
(Cooling operation)
During the cooling operation, the four-way switching valve 22 is in the state shown by the solid line in FIG. 1, the discharge side of the compressor 21 is connected to the gas side of the outdoor heat exchanger 23, and the suction side of the compressor 21 is indoor heat exchange. The gas is connected to the gas side of the vessel 42. The outdoor expansion valve 35 is open.

  In this state, when the compressor 21 is started, the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 is introduced into the outdoor heat exchanger 23. The gas refrigerant exchanges heat with outdoor air in the outdoor heat exchanger 23 and condenses to become a high-temperature and high-pressure liquid refrigerant toward the indoor expansion valve 41. The high-temperature and high-pressure liquid refrigerant is decompressed by the indoor expansion valve 41 to become a low-temperature and low-pressure gas-liquid two-phase refrigerant and enters the indoor heat exchanger 42. The gas-liquid two-phase refrigerant exchanges heat with indoor air in the indoor heat exchanger 42 to become a gas refrigerant, and is sucked into the compressor 21 again.

(Heating operation)
During the heating operation, the four-way switching valve 22 is in the state indicated by the broken line in FIG. 1, the discharge side of the compressor 21 is connected to the gas side of the indoor heat exchanger 42, and the suction side of the compressor 21 is the outdoor heat exchanger 23. The gas side is contacted. The degree of opening of the outdoor expansion valve 35 is adjusted in order to reduce the refrigerant going to the outdoor heat exchanger 23 to an evaporation pressure at which the refrigerant can be evaporated in the outdoor heat exchanger 23. Further, the indoor expansion valve 41 is opened.

  In this state, when the compressor 21 is started, the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 is introduced into the indoor heat exchanger 42. The gas refrigerant is condensed by exchanging heat with indoor air in the indoor heat exchanger 42 to become a high-temperature and high-pressure liquid refrigerant. The liquid refrigerant that has exited the indoor heat exchanger 42 is decompressed by the outdoor expansion valve 35, becomes a low-temperature / low-pressure gas-liquid two-phase refrigerant, and enters the outdoor heat exchanger 23. This gas-liquid two-phase refrigerant exchanges heat with outdoor air in the outdoor heat exchanger 23 to become a gas refrigerant, and is sucked into the compressor 21 again.

  Even when the temperature of the refrigerant flowing through the low-pressure side of the refrigerant circuit 10 is lower than the freezing temperature of water during the heating operation and the water mixed in the refrigerant freezes to generate ice particles, the ice particles pass through the filter 354. Filter 354 is not clogged with ice particles.

<Features>
In the air conditioner 1, a filter 354 for removing metal powder such as dust and rust is provided on the low pressure side of the refrigerant circuit 10. As the filter 354, a filter that satisfies the condition of 80 μm <opening A <160 μm is employed.

  As described above, according to the present invention, it is useful for an air conditioner in which moisture is mixed into a pipe during installation and the moisture may freeze during operation.

The schematic block diagram of the air conditioning apparatus which concerns on one Embodiment of this invention. The perspective view of the filter apparatus of the air conditioning apparatus which concerns on this embodiment. The top view which shows the opening of a filter.

Explanation of symbols

1 Air Conditioner 10 Refrigerant Circuit 354 Filter

Claims (3)

An air conditioner in which a filter (354) for removing foreign matter is attached to the low pressure side of the vapor compression refrigerant circuit (10),
The mesh opening of the filter (354) is set to a size that does not cause blockage by ice particles generated by freezing of water contained in the refrigerant.
Air conditioner (1). The mesh opening of the filter (354) is larger than 80 μm,
The air conditioner (1) according to claim 1. The mesh opening of the filter (354) is smaller than 160 μm,
The air conditioner (1) according to claim 2.

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