Refrigeration – Refrigeration producer – Compressor-condenser-evaporator circuit
Reexamination Certificate
2002-12-13
2004-03-23
Doerrler, William C. (Department: 3744)
Refrigeration
Refrigeration producer
Compressor-condenser-evaporator circuit
C062S474000
Reexamination Certificate
active
06708522
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a receiver tank for use in a refrigeration cycle, a heat exchanger with a receiver tank, and a condensing apparatus for use in a refrigeration cycle, which can be applied to an air-conditioning system for automobile use, household use and business use.
2. Description of Related Art
FIG. 22
shows an expansion-valve system refrigeration cycle as one of typical refrigeration cycles. In the refrigeration cycle, the gaseous refrigerant of high temperature and high pressure sent out from a compressor CP is introduced into a condenser CD and exchanges heat with the ambient air to be cooled and condensed therein. The condensed refrigerant mostly in a liquefied state flows into a receiver-tank RT to be completely separated into gaseous refrigerant and liquefied refrigerant. Then, only the liquefied refrigerant flows out of the receiver-tank RT. The liquefied refrigerant is decompressed and expanded quickly by an expansion-valve EV, and is introduced into an evaporator EP as a mist-like refrigerant of low pressure and low temperature. This mist-like refrigerant evaporates in the evaporator EP by absorbing latent heat from the ambient air to be turned into gaseous refrigerant. Then, the gaseous refrigerant flows out of the evaporator EP, and is inhaled by the compressor CP.
In
FIG. 22
, the spotted area indicates that the refrigerant is in a liquid state. In the meantime, the refrigeration flow rate is controlled by adjusting the opening degree of the expansion-valve EV in response to the signal sent from a heat-sensitive-coupler SC provided at the outlet side of the evaporator EP.
Now, in a refrigeration cycle for automobile use, it is proposed that refrigerant condensed in a condenser CD is subcooled to a temperature lower than the condensation temperature of the refrigerant by about several degrees to increase the amount of heat release and thereafter the subcooled refrigerant is introduced into an expansion-valve EV and an evaporator EP to enhance the refrigerating capacity. Concretely, the subcooling portion, which subcools the refrigerant condensed by the condenser CD to a temperature lower than the condensation temperature of the refrigerant by several degrees centigrade, is provided so as to send the condensed refrigerant to the evaporator side as stabilized liquid refrigerant. Usually, this subcooling portion is arranged at the downstream side of the receiver-tank RT. In many cases, such a subcooling portion is integrally provided to the condenser CD (subcool system condenser) in view of space efficiency.
On the other hand, in many cases, a receiver-dryer is used as the aforementioned receiver-tank RT. The receiver-dryer is provided with a desiccant-filled-portion therein to absorb the moisture components of the refrigerant. Such a receiver-dryer includes the so-called sandwich-type receiver-dryer having an upper space
33
above a desiccant-filled portion
32
and a lower space
34
below the desiccant-filled portion
32
in a vertical tank
31
as shown in
FIGS. 23A-23C
, and the so-called bag-type receiver-dryer provided with a desiccant-filled portion
32
in one side in a vertical tank
31
as shown in FIG.
23
D.
In the receiver-dryer having a sucking-pipe
36
shown in
FIG. 23A
, the refrigerant flowed into the upper space
33
via the refrigerant inlet
35
passes through the desiccant-filled-portion
32
to reach the lower space
34
. Then, the liquefied refrigerant separated from the gaseous refrigerant is sucked up by the sucking-pipe
36
and flows out of the refrigerant outlet
37
provided at the top of the tank.
In the receiver-dryer having a supplying-pipe
38
shown in
FIG. 23B
, the refrigerant introduced from the refrigerant inlet
35
provided at the bottom portion flows up the supplying-pipe
38
to reach the upper space
33
, and then passes through the desiccant-filled-portion
32
to reach the lower space
34
. Then, the liquefied refrigerant separated from the gaseous refrigerant flows out of the refrigerant outlet
37
provided at the bottom of the tank.
In the inlet-outlet-confrontation-type receiver-dryer shown in
FIG. 23C
, the refrigerant introduced into the upper space
33
via the top refrigerant inlet
35
passes through the desiccant-filled-portion
32
to reach the lower space
34
. Then, the liquefied refrigerant separated from the gaseous refrigerant flows out of the refrigerant outlet
37
provided at the bottom of the tank.
In the bag-type receiver-dryer shown in
FIG. 23D
, the refrigerant flowed into the tank via the refrigerant inlet
35
provided at the side portion of the tank contacts the desiccant-filed-portion
32
, and the liquefied refrigerant separated from the gaseous refrigerant in the lower portion of the tank flows out of the refrigerant outlet
37
provided at the bottom of the tank.
In an air-conditioning system, it is always desired to improve the space efficiency and performance. Especially, in an automobile air-conditioner, in order to effectively use the limited body space, it is requested that the whole system be further miniaturized. In order to realize the aforementioned requests, it is necessary to reduce the amount of refrigerant sealed in the refrigeration cycle, to enhance the performance stability to load fluctuation (overcharge toughness) and to prevent performance deterioration with time due to a continuous running (decline of leakage toughness). For these purposes, it is desired to secure a steady region, i.e., a stable region in a subcooled state of the refrigerant to the amount of sealed refrigerant, as widely as possible.
FIG. 8
is a correlation characteristic figure showing the correlation between a subcooling degree of the condensed refrigerant and an amount of sealed refrigerant obtained by a charge examination (cycle bench) of an automobile air-conditioner. In this correlation characteristic figure, it is ideal that the rising curve is steep until it reaches a steady region as shown by the phantom-line curve X
2
and that the steady region has a wider range.
However, in an automobile air-conditioner using a conventional subcooling system condenser, the rising curve is gentle until it reaches the steady region as shown by the solid-line curve Y. Therefore, the steady region starting point delays toward the larger amount of sealed refrigerant side, which results in a delayed refrigerant sealing timing and a narrow steady region width. This means that in the conventional automobile air-conditioner the miniaturization by decreasing the sealed refrigerant amount is difficult, the performance stability to load fluctuation is bad, and the performance tends to deteriorate with time due to a continuous running.
The inventors investigated causes of the above-mentioned problems of the conventional automobile air-conditioner from various aspects so as to realize a miniaturized high-performance automobile air-conditioner. Consequently, the inventors revealed that one factor of the above-mentioned problems resides in a structure of a conventional receiver-dryer RD. That is, since the interface between the liquefied refrigerant and the gaseous refrigerant, i.e., the surface of the liquefied refrigerant, near the refrigerant outlet of the receiver-dryer RD is hard to become stable, the stable supply of the liquefied refrigerant to the following cycle part cannot be performed. Furthermore, a large amount of gaseous refrigerant will be mixed into the liquefied refrigerant to be flowed out. Therefore, the above-mentioned steady region becomes narrower and the steady region starting point delays toward the larger amount of sealed refrigerant side.
That is, since a refrigerant flow velocity flowing into a receiver-dryer RD from a condenser CD is generally high, in a sandwich-type receiver-dryer, larger turbulence of the liquefied refrigerant occurs in the upper space
33
into which the refrigerant is introduced. Consequently, since the liquefied refrigerant stagnates in the upper space
33
, the liquefied refrigerant is not fully suppl
Kamoshida Osamu
Seno Yoshihiko
Takahashi Yasuhiro
Yamazaki Keiji
Doerrler William C.
Showa Denko K.K.
LandOfFree
Receiver tank for use in refrigeration cycle, heat exchanger... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Receiver tank for use in refrigeration cycle, heat exchanger..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Receiver tank for use in refrigeration cycle, heat exchanger... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3266571