Heat exchange – With timer – programmer – time delay – or condition responsive... – Having heating and cooling capability
Reexamination Certificate
2002-01-14
2004-06-15
Ciric, L V (Department: 3753)
Heat exchange
With timer, programmer, time delay, or condition responsive...
Having heating and cooling capability
C062S185000, C219S494000, C165S297000
Reexamination Certificate
active
06749016
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a brine temperature control apparatus, for controlling brine within a wide temperature range, and more specifically concerns a brine temperature control apparatus using a three-way proportional valve in the brine circulating fluid path.
2. Description of the Related Art
Formerly, when the temperature of brine which is supplied to a load is to be controlled inside a temperature range of −30° C. to +80° C., driving of a cooling unit (also referred to as a “chiller”) is first halted and then applied heat is supplied to the brine from a heater.
FIG. 3
illustrates an example of a known type of brine temperature control apparatus, in which a cooling unit
1
is constructed by a compressor
4
, a condenser
5
, an expansion valve
6
and a heat exchanger
7
connected together successively in series. In the case that the temperature of the brine is controlled over a wider temperature range, the cooling unit may be made up of an array of plural units.
On the other hand, the circulating circuit
2
is constructed by a brine tank
11
, a pump
12
and a load
13
connected successively in series, wherein the heat exchanger
7
and a heater
14
are disposed inside the tank
11
. Driving and halting of the cooling unit
1
, along with supply of electricity to the heater
14
, are controlled by a temperature controller
16
, which is operated in accordance with a temperature sensor which detects the brine temperature in the tank
11
.
In this known type of temperature control apparatus, for example, when the temperature of the brine is controlled at +80° C., a control is performed in which only one cooling unit
1
is operated as a cooling source, and heat is also applied from the heater
14
to the brine in the tank
11
, that has been cooled by the cooling unit
1
.
Further, when the temperature of the brine is controlled at +30° C., a control is performed in which two cooling units
1
,
1
are operated as the cooling source (such an arrangement of two cooling units is not actually shown in
FIG. 3
although such a structure is easily understood), while heat is applied by the heater
14
. When the brine temperature is to be controlled at −30° C., a control is performed in which multiple cooling units
1
are operated simultaneously. In all of these examples, after the brine has been cooled in excess of the received heat from the load
13
, heat must be applied from the heater
14
.
As described above, when controlling brine temperature according to this known type of temperature control apparatus, a plurality of cooling units
1
may be operated for controlling brine temperature, however, there is a limit to the precision of the temperature control by operating and halting of the cooling units
1
. For raising precision, after cooling in excess of a predetermined temperature, it is necessary to apply heat using the heater
14
, so there is a problem of a large wasting of energy.
In order to address such a problem, according to Japanese Utility Model Disclosure Document No. 5-17535, a temperature control apparatus has been proposed in which it is possible to control temperature over a wider temperature range with higher precision, and moreover, in which energy consumption is lower. Such an apparatus, as shown in
FIG. 4
, is characterized by a refrigeration circuit and cooling liquid circulating circuit, wherein the cooling liquid circulating passage further comprises an auxiliary coolant path
78
which branches from an outlet side of the pump
74
, and then passes through an ON/OFF type of electromagnetic valve
79
and the heat-exchanger
61
, providing fluid transport in a recirculating manner back to the tank
62
. Further, the temperature controller
76
causes the ON/OFF type electromagnetic valve
79
to open when the temperature of the cooling liquid in the tank
72
is higher than a preset temperature, and causes electricity to be supplied to the heater
73
when the cooling liquid temperature falls below a preset temperature.
The basic operation of the this known type of apparatus may be described as follows, with reference to FIG.
5
. When the temperature of the cooling liquid in the tank
72
is higher than, for example 0.4° C. above, a preset temperature, the ON/OFF electromagnetic valve
79
is opened by the temperature controller
76
, so that the cooling liquid which flows through the auxiliary coolant flow path
78
is chilled by the heat exchanger and quickly recirculates back to the tank
72
. In the case that the cooling liquid temperature becomes lower than the preset temperature set in the temperature controller
76
, for example 0.1° C. below the preset temperature, the ON/OFF electromagnetic valve
79
is closed. In addition when the temperature falls about 0.4° C. below the preset temperature, heat is applied from the heater
73
, until the temperature rises to about 0.35° C. below the preset temperature, at which point the heater
73
is turned off. Thus, by combined operations of the electromagnetic valve
79
and the heater
73
, the temperature of the cooling liquid in the tank
72
can be maintained inside the preset temperature range of the temperature controller
76
.
Because cooling of the cooling liquid in the auxiliary coolant path
78
, as well as application of heat by the heater
73
, is selectively performed by raising and lowering the cooling liquid temperature with respect to the preset temperature range, compared to the case of applying heat by a heater to a previously-cooled cooling liquid for controlling to a set temperature range, consumption of energy can be lessened overall, while notwithstanding, the temperature control is highly accurate. Further, by selectively cooling and applying heat to the cooling liquid, control over a wider temperature range is made possible.
However, the apparatus according to Japanese Utility Model Disclosure Document No. 5-17535 has experienced problems of its own. In particular, this apparatus uses an electromagnetic ON/OFF type valve
79
and a heater
73
, making up an ON/OFF system, which enables temperature control over a wide range from about −20° C. to +90° C. However, because of use of the ON/OFF type of electromagnetic valve
79
, during abrupt ON/OFF switching operations of the electromagnetic valve, an undesirable “water hammer” effect has been generated. The problem is all the more aggravated in the case of large capacity chiller units, resulting in a cumbersome and vexing disadvantage which has yet to be fully solved. Because of the water hammer effect, it has not been possible to implement this system in large capacity chiller units.
SUMMARY OF THE INVENTION
The present invention is a brine temperature control apparatus in which the temperature of brine in a tank disposed in a brine fluid circulating passage is controlled using a three-way proportional valve. Because the three-way proportional valve does not open and close in an abrupt ON/OFF fashion, but rather the degree of opening on the side for supplying chilled brine is gradually adjusted in proportion to a detection signal indicative of the brine temperature in the tank, a water hammer problem is avoided, and therefore a coolant circulating circuit including such a three-way proportional valve can be used effectively even with large capacity cooling units.
The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.
REFERENCES:
patent: 2466769 (1949-04-01), Herold et al.
patent: 2788264 (1957-04-01), Bremer et al.
patent: 3262492 (1966-07-01), Meenan
patent: 4042011 (1977-08-01), Schneider
patent: 4218885 (1980-08-01), White
patent: 4984628 (1991-01-01), Uchida et al.
patent: 6003595 (1999-12-01), Watanabe
patent: 6109346 (2000-08-01), Hill
patent: 6397943 (2002-06-01), Egara
patent: 6614353 (
Ciric L V
Guss Paul A.
SMC Kabushiki Kaisha
LandOfFree
Brine temperature control apparatus using a three-way... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Brine temperature control apparatus using a three-way..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Brine temperature control apparatus using a three-way... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3356743