Refrigeration – Refrigeration producer – Compressor-condenser-evaporator circuit
Reexamination Certificate
2001-04-20
2002-08-06
Doerrler, William (Department: 3744)
Refrigeration
Refrigeration producer
Compressor-condenser-evaporator circuit
Reexamination Certificate
active
06427480
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application is related to Japanese Patent Applications No. 2000-126161 filed on Apr. 26, 2000, No. 2000-279956 filed on Sep. 14, 2000, No. 2001-1535 filed on Jan. 9, 2001, No. 2001-43971 filed on Feb. 20, 2001, and No. 2001-50923 filed on Feb. 26, 2001, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a refrigerant cycle system suitable for an air conditioner for a vehicle and the like.
2. Description of Related Art
A conventional basic structure of a refrigerant cycle system is roughly divided into a receiver cycle and an accumulator cycle based on a difference between control of a super-heating degree of refrigerant at an outlet of an evaporator and control of a super-cooling degree of refrigerant at an outlet of a condenser.
As shown in the Mollier diagram of
FIG. 52
, the receiver cycle cools and condenses refrigerant discharged from a compressor
101
by a condenser
102
, the refrigerant from the outlet of the condenser
102
is separated into gas and liquid refrigerant by a receiver
107
provided on the outlet side of the condenser
102
. The liquid refrigerant from the receiver
107
is made to be expand and decompressed by a thermal type expansion valve
131
, and then the low-pressure refrigerant after this decompression is evaporated by absorbing heat from air in an evaporator
104
.
In this receiver cycle, since a gas-liquid interface of the refrigerant is formed within the receiver
107
and the refrigerant within the receiver
107
is maintained above a saturated liquid line L
2
, the super-cooling degree SC of the refrigerant at outlet of the condenser
102
is controlled to 0° C. On the other hand, the thermal type expansion valve
131
feeds back the super-heating degree SH of the refrigerant at outlet of the evaporator
104
to automatically adjust a valve opening for thereby maintaining the super-heating degree SH of the refrigerant at the outlet of the evaporator
104
within a predetermined range (for example, 3 to 15° C.).
On the other hand, in the accumulator cycle, as shown in the Mollier diagram of
FIG. 53
, a fixed restrictor
103
(fixed throttle) such as a capillary tube is directly connected to the output of the condenser
102
to directly decompress the refrigerant from the outlet of the condenser
102
in the fixed restrictor
103
. Then, the low-pressure refrigerant after the decompression absorbs heat in the evaporator
104
for evaporation, and the refrigerant, which passed through this evaporator
104
, is made to be flowed into an accumulator
108
. Thereafter, the refrigerant from the outlet of the evaporator is separated into gas refrigerant and liquid refrigerant in the accumulator
108
, and gas refrigerant within the accumulator
108
is sucked into a compressor
101
.
In the accumulator cycle, since a gas-liquid interface of the refrigerant is formed within the accumulator
108
and the refrigerant within the accumulator
108
is maintained above a saturated gas line L
1
, the super-heating degree SH of the refrigerant sucked into the compressor
1
is maintained at 0° C. Because the fixed restrictor
103
is used as decompression means, the super-cooling degree SC of the refrigerant at outlet of the condenser
102
is determined depending on flow amount characteristics of the fixed restrictor
103
, a cycle high pressure and a cycle refrigerant flow rate, and the super-cooling degree SC normally fluctuates in a range of 0 to about 20° C. because of fluctuations in cycle operating conditions.
However, in the former receiver cycle, since the thermal type expansion valve
131
feeds back the super-heating degree SH of the refrigerant at the outlet of the evaporator
104
to automatically adjust a valve opening, the receiver cycle system needs a complicate and precise valve mechanism, leading to an increase in cost.
In order for the thermal type expansion valve
131
to sense the super-heating degree SH of the refrigerant at outlet of the evaporator
104
, there arises the need for setting an installation place for the thermal type expansion valve
131
in the vicinity of the evaporator
104
, in other words, in a compartment. As a result, passage noise of the refrigerant, which occurs in a restriction passage of the thermal type expansion valve
131
, becomes prone to propagate to an air conditioner user (occupant) within the compartment, and a problem of refrigerant passage noise becomes obvious.
In contrast, in the accumulator cycle, since the fixed restrictor
103
is used as the decompression means, this can be manufactured at exceedingly low cost as compared with the thermal type expansion valve
131
. Since it is not necessary to place the fixed restrictor
103
in the vicinity of the evaporator, but the fixed restrictor
103
can be placed on the outside of the compartment (e.g., engine room side of the vehicle), there is an advantage that the refrigerant passage noise to be transmitted into the compartment can be greatly reduced. However, in a refrigerant cycle system for vehicle air conditioning, however, because the compressor
101
is driven by a vehicle engine, the number of revolutions of the compressor
101
also fluctuates greatly with the fluctuation in the speed of the engine. For this reason, if the fixed restrictor
103
is used for the decompression means, a refrigerant flow adjusting operation cannot be correspond sufficiently to the great fluctuation in the number of revolutions of the compressor
101
to greatly fluctuate the super-cooling degree SC of the refrigerant at outlet of the condenser, resulting in excessive fluctuation width. For example, when the compressor
101
is revolving at high speed, the compressor discharging capacity is increased, and the high pressure discharged from the compressor
101
is increased so that the super-cooling degree SC of the refrigerant at outlet of the condenser becomes too great. This occurrence of the excessive super-cooling degree SC causes an increase in a compressor driving power due to the increased high pressure to worsen the cycle efficiency.
In addition, there is another disadvantage that the accumulator
108
has inferior mountability. More specifically, the accumulator
108
is provided at the outlet side of the evaporator
104
, that is, in a low-pressure passage, for separating gas-liquid of the low-pressure refrigerant having a large specific volume, it is necessary to make the capacity of the accumulator
8
larger than that of the receiver
107
provided at the high pressure side. Accordingly, when the refrigerant cycle equipments are mounted within such narrow space as the inside of a vehicle engine compartment, the mountability of the accumulator
108
will be more worsen than the receiver
107
.
SUMMARY OF THE INVENTION
In view of the foregoing problems, it is an object of the present invention to provide a refrigerant cycle system with an improvement structure, which readily controls a super-heating degree of refrigerant discharged from a compressor and a super-heating degree at a refrigerant outlet side of an evaporator.
It is an another object of the present invention to provide a refrigerant cycle system with a compact structure, which can improve a cycle efficiency.
According to the present invention, in a refrigerant cycle system, a condenser for cooling and condensing refrigerant discharged from a compressor includes a first heat exchange unit, a second heat exchange unit at a downstream side of the first heat exchange unit in a refrigerant flow direction, and a gas liquid separator arranged between the first heat exchange unit and the second heat exchange unit in the refrigerant flow direction in such a manner that refrigerant discharged from a compressor is cooled in the first heat exchange unit and at least gas refrigerant separated in the gas-liquid separator flows into the second heat exchange unit. In the condenser, a refrigerant state flowing from the first heat exchange unit to the gas-liquid separ
Hotta Teruyuki
Inaba Atsushi
Ito Shigeki
Yamanaka Yasushi
Yamasaki Kurato
Denso Corporation
Doerrler William
Drake Malik N.
Harness Dickey & Pierce PLC
LandOfFree
Refrigerant cycle system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Refrigerant cycle system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Refrigerant cycle system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2973307