Refrigeration – Refrigeration producer – Compressor-condenser-evaporator circuit
Reexamination Certificate
1999-09-17
2001-04-10
McDermott, Corrine (Department: 3744)
Refrigeration
Refrigeration producer
Compressor-condenser-evaporator circuit
Reexamination Certificate
active
06212903
ABSTRACT:
This application is the national phase under 35 U.S.C. §371 of PCT International Application No. PCT/JP98/00820 which has an International filing date of Feb. 27, 1998, which designated the United States of America.
TECHNICAL FIELD
The present invention relates to an air conditioner which uses an alternative refrigerant for a hydrochlorofluorocarbon base refrigerant HCFC-22, as a refrigerant that circulates through a refrigerant circuit.
BACKGROUND ART
Generally, an air conditioner comprises an outdoor unit equipped with a compressor, an outdoor heat exchanger, a pressure reducing mechanism and the like, and an indoor unit equipped with an indoor heat exchanger. The outdoor unit and the indoor unit are connected to each other with connection piping comprising a gas pipe, a liquid pipe or the like, and thereby a refrigerant circuit is formed between the outdoor unit and the indoor unit. In such an air conditioner, the refrigerant is circulated in the refrigerant circuit by driving the compressor, and thereby heat absorbed by the outdoor heat exchanger is released by the indoor heat exchanger so that heating operation is performed, or thereby heat absorbed by the indoor heat exchanger is released by the outdoor heat exchanger so that cooling operation is performed.
In this air conditioner, heat is transferred by means of the refrigerant as shown above, and thereby air conditioning operation is enabled. Therefore, the rate of refrigerant circulation expressed in refrigerant weight flowing per unit time needs to be increased or decreased depending on the air conditioning power of the equipment. However, when the refrigerant circulation rate is increased, leaving the gas pipe thickness as it is without changes would cause pressure loss due to the gas pipe to increase so that the air conditioning power would lower. On this account, in this air conditioner, the diameter of the gas pipe is changed according to the refrigerant circulation rate. For example, when HCFC-22 conventionally in common use is used as the refrigerant, gas pipes having a diameter of about 12.7 mm (hereinafter, referred to as “{fraction (4/8)}-dia. pipe”) is used in middle-sized and large-sized air conditioners whose refrigerant circulation rate is about 100 kg/h (kilogram per hour, likewise hereinafter) or about 150 kg/h or so. In small-sized air conditioners whose refrigerant circulation rate is about 60 kg/h or about 80 kg/h or so, gas pipes having a diameter of about 9.5 mm (hereinafter, referred to as “⅜-dia. pipe”) are used. That is, it is a normal mode of application with use of HCFC-22 as the refrigerant that, a {fraction (4/8)}-dia. pipe is used as the aforementioned gas pipe in middle-sized and large-sized air conditioners whose rated cooling power is not less than 4.0 kW as defined by “JIS C 9612” of Japanese Industrial Standards, while a ⅜-dia. pipe is used as the gas pipe in small-sized air conditioners whose rated cooling power is less than 4.0 kW. Then, by changing the diameter of the gas pipe according to the air conditioning power of the air conditioner, a reduction in pressure loss is implemented in the middle-sized and large-sized air conditioners, and construction work is facilitated in the small-sized air conditioners. Besides, a cost reduction is implemented. It is noted that the cooling power as defined by “JIS C 9612” of Japanese Industrial Standards refers to a “quantity of heat (kW) that is removed in unit time from indoors when a room air conditioner is cooling operated”.
In recent years, a demand for cost reduction to air conditioners and a demand for improvement in workability have been increasing more and more. In particular, the {fraction (4/8)}-dia. pipes are difficult to bend by hand in installation, which makes a cause of hindering the improvement in workability. However, only making the gas pipe smaller in diameter would cause occurrence of a problem that the pressure loss in the refrigerant circuit increases with the result of lowered air conditioning power.
Meanwhile, since HCFC-22 conventionally used as the refrigerant has become a target of fluorine regulation, alternative refrigerants substituting for HCFC-22 have begun to be discussed in various ways. However, there has been provided no alternative refrigerant that shows physical property values equivalent to or higher than the refrigerant HCFC-22 in all the aspects. Accordingly, which alternative refrigerant is appropriate for use is now under discussions, depending on the purpose of use.
DISCLOSURE OF THE INVENTION
The present invention having been achieved to solve these and other disadvantages of the prior art, an object of the invention is to implement cost reduction as well as workability enhancement while avoiding any decrease in the air conditioning power.
In order to achieve the above object, the present invention provides an air conditioner in which a refrigerant circuit is formed by connecting an outdoor unit and an indoor unit to each other with communication piping including a gas pipe and a liquid pipe, and in which a hydrofluorocarbon base refrigerant R-410A is circulated through the refrigerant circuit so that air conditioning operation is performed, wherein cooling power is substantially not less than 4 kW, and the gas pipe has an outer diameter of substantially 9.5 mm and a wall thickness of substantially 0.8 mm.
With this constitution, the air conditioner is a middle-sized or large-sized air conditioner having a cooling power of substantially not less than 4 kW, and the gas pipe has an outer diameter of substantially 9.5 mm and a wall thickness of substantially 0.8 mm, thus smaller in diameter than gas pipes commonly used when the hydrochlorofluorocarbon base refrigerant HCFC-22 is used. Therefore, it becomes possible to work by hand with the communication piping comprising the gas pipe, the liquid pipe and the like, so that the workability enhancement is achieved. Further, cost reduction is achieved with the downsizing of the gas pipe. In this case, the hydrofluorocarbon base refrigerant R-410A large in volumetric power than the HCFC-22 is used as the refrigerant to be circulated through the refrigerant circuit, so that any increase in pressure loss due to the diameter reduction of the gas pipe is suppressed and that temperature loss due to the pressure loss is reduced.
Consequently, according to this invention, further cost reduction and workability enhancement are achieved while decrease in the air conditioning power is avoided.
Also, the present invention provides an air conditioner in which a refrigerant circuit is formed by connecting an outdoor unit and an indoor unit to each other with communication piping including a gas pipe and a liquid pipe, and in which a hydrofluorocarbon base refrigerant R-410A is circulated through the refrigerant circuit so that air conditioning operation is performed, wherein cooling power is substantially less than 4 kW, and the gas pipe has an outer diameter of substantially 7.9 mm and a wall thickness of substantially 0.8 mm.
With this constitution, the air conditioner is a small-sized air conditioner having a cooling power of substantially less than 4 kW, and the gas pipe has an outer diameter of substantially 7.9 mm and a wall thickness of substantially 0.8 mm, thus smaller in diameter than gas pipes commonly used when the hydrochlorofluorocarbon base refrigerant HCFC-22 is used. Therefore, it becomes possible to achieve workability enhancement and cost reduction. In this case, the refrigerant R-410A larger in volumetric power than the HCFC-22 is used as the refrigerant to be circulated through the refrigerant circuit, so that increase in pressure loss due to the diameter reduction of the gas pipe is suppressed and that temperature loss due to the pressure loss is reduced. Thus, any decrease in air conditioning power is avoided.
Also, the present invention provides an air conditioner in which a refrigerant circuit is formed by connecting an outdoor unit and an indoor unit to each other with communication piping including a gas pipe and a liquid pipe,
Natsume Toshiyuki
Okamoto Takahiro
Shigenaga Masaya
Yano Yukimasa
Birch & Stewart Kolasch & Birch, LLP
Daikin Industries Ltd.
Drake Malik N.
McDermott Corrine
LandOfFree
Air conditioner does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Air conditioner, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Air conditioner will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2454409