U.S. patent application number 12/633794 was filed with the patent office on 2011-06-09 for electronic instrument for refrigerant recovery machine.
This patent application is currently assigned to SUN-WONDER INDUSTRIAL CO., LTD.. Invention is credited to An-Chao CHANG.
Application Number | 20110132018 12/633794 |
Document ID | / |
Family ID | 44080639 |
Filed Date | 2011-06-09 |
United States Patent
Application |
20110132018 |
Kind Code |
A1 |
CHANG; An-Chao |
June 9, 2011 |
ELECTRONIC INSTRUMENT FOR REFRIGERANT RECOVERY MACHINE
Abstract
Used in a refrigerant recovery machine having a refrigerant
input pipe and a refrigerant output pipe, an electronic instrument
is disclosed to include a control unit, a LCD device controllable
by the control unit to display the operation status of the
refrigerant recovery machine, and a pressure sensor unit having an
input pipe pressure sensor and an output pipe pressure sensor for
detecting the pressure in the input pipe and the pressure in the
output pipe and transmitting the respective detected pressure
values to the control unit for comparison with a pre-set pressure
threshold limit value so that the control unit controls the
operation of the refrigerant recovery machine subject to the
comparison results.
Inventors: |
CHANG; An-Chao; (Lungshou
Village, TW) |
Assignee: |
SUN-WONDER INDUSTRIAL CO.,
LTD.
Lungshou Village
TW
|
Family ID: |
44080639 |
Appl. No.: |
12/633794 |
Filed: |
December 8, 2009 |
Current U.S.
Class: |
62/298 ;
62/336 |
Current CPC
Class: |
F25B 2700/21 20130101;
F25B 2345/002 20130101; F25B 2700/19 20130101; F25B 2345/0051
20130101; F25B 2345/003 20130101; F25B 45/00 20130101 |
Class at
Publication: |
62/298 ;
62/336 |
International
Class: |
F25D 25/00 20060101
F25D025/00 |
Claims
1. An electronic instrument used in a refrigerant recovery machine
comprising a refrigerant pipe system, a compressor pipe line and a
condenser pipe line, said refrigerant pipe system having an input
pipe and an output pipe, the electronic instrument comprising: a
control unit for controlling the operation of said refrigerant
recovery machine, said control unit comprising a microprocessor
having set therein at least one pressure threshold limit value; a
liquid crystal display device electrically connected to said
control unit and controllable by said control unit to display
status of said refrigerant recovery machine; and a pressure sensor
unit electrically connected to said control unit, said pressure
sensor unit comprising an input pipe pressure sensor adapted to
detect the pressure in said input pipe and to transmit the detected
temperature value to said control unit for comparison with one said
pressure threshold limit value and an output pipe pressure sensor
adapted to detect the pressure in said input pipe and to transmit
the detected temperature value to said control unit for comparison
with one said pressure threshold limit value.
2. The electronic instrument as claimed in claim 1, wherein said at
least one pressure threshold limit value comprises a high-pressure
threshold limit value and a negative pressure threshold limit
value.
3. The electronic instrument as claimed in claim 1, further
comprising a temperature sensor unit electrically connected to said
microprocessor of said control unit, said temperature sensor unit
comprising an input pipe temperature sensor adapted to detect the
temperature in said input pipe and to transmit the detected
temperature value to said microprocessor for comparison with a
predetermined temperature threshold limit value set in said
microprocessor, an output pipe temperature sensor adapted to detect
the temperature in said output pipe and to transmit the detected
temperature value to said microprocessor for comparison with said
predetermined temperature threshold limit value, a compressor pipe
line temperature sensor adapted to detect the temperature in said
compressor pipe line and to transmit the detected temperature value
to said microprocessor for comparison with said predetermined
temperature threshold limit value and a condenser pipe line
temperature sensor adapted to detect the temperature in said
condenser pipe line and to transmit the detected temperature value
to said microprocessor for comparison with said predetermined
temperature threshold limit value.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to refrigerant recovery
technology and more particularly, to an electronic instrument for
use in a refrigerant recovery machine to control the operation of
the refrigerant recovery machine in collecting the refrigerant from
the main unit of a cooler or refrigerator.
[0003] 2. Description of the Related Art
[0004] A refrigerant recovery machine is adapted to draw the
refrigerant out of the main unit of a system (room cooler, car
cooler, central air conditioning system or refrigerator) into a
recovery tank. However, a conventional refrigerant recovery machine
must be equipped with an extra high-pressure mechanical type safety
pressure switch and an extra mechanical vacuum type safety pressure
switch. These two safety switches are respectively connected to the
valve blocks in the refrigerant input pipe and refrigerant output
pipe of the refrigerant recovery machine. When the input or output
pressure of the refrigerant recovery machine surpasses a respective
predetermined pressure threshold limit value, the respective safety
switch switches off the refrigerant recovery machine, assuring
operational safety. However, these mechanical safety switches have
a broad range of pressure error and tend to cause an incomplete
refrigerant drawing problem. Further, these mechanical safety
switches are commonly heavy and expensive, increasing the cost of
the refrigerant recovery machine and complicating the installation
of the piping.
[0005] Further, during the operation of a refrigerant recovery
machine, the pipes of the refrigerant recovery machine may be
clogged with the dirty refrigerant. Clogging of the pipes may cause
freezing of the refrigerant, resulting in an abnormal pressure
value and affecting the drawing of the refrigerant.
SUMMARY OF THE INVENTION
[0006] The present invention has been accomplished under the
circumstances in view. It is the main object of the present
invention to provide an electronic instrument for refrigerant
recovery machine, which detects the pressure of the pipes in the
refrigerant recovery machine and compares the detected pressure
values with predetermined pressure threshold limit values, and then
controls the operation of the refrigerant recovery machine subject
to the pressure comparison results, enabling the refrigerant
recovery machine to draw the refrigerant from the main unit of a
refrigerator or cooler accurately and safely.
[0007] It is another object of the present invention to provide an
electronic instrument for refrigerant recovery machine, which
detects the temperature of the pipes in the refrigerant recovery
machine and compares the detected temperature values with a
predetermined temperature threshold limit value, and then controls
the operation of the refrigerant recovery machine subject to the
temperature comparison result, enabling the refrigerant recovery
machine to draw the refrigerant from the main unit of a
refrigerator or cooler accurately and safely.
[0008] To achieve these and other objects of the present invention,
an electronic instrument is used in a refrigerant recovery machine
comprising a refrigerant pipe system having an input pipe and an
output pipe, a compressor pipe line and a condenser pipe line. The
electronic instrument comprises a control unit, a LCD device
controllable by the control unit to display the operation status of
the refrigerant recovery machine, a pressure sensor unit and a
temperature sensor unit for detecting the pressure in the input
pipe and the output pipe and the temperature in the input pipe, the
output pipe, the compressor pipe line and the condenser pipe line
and transmitting the respective detected pressure and temperature
values to the control unit for comparison with pre-set pressure
threshold limit values and temperature threshold limit values so
that the control unit controls the operation of the refrigerant
recovery machine subject to the comparison results.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an elevational view of a refrigerant recovery
machine carrying an electronic instrument in accordance with the
present invention.
[0010] FIG. 2 is a system block diagram of the refrigerant recovery
machine shown in FIG. 1.
[0011] FIG. 3 is a system block diagram of the electronic
instrument in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] Referring to FIGS. 1-3, a refrigerant recovery machine 1 is
shown carrying an electronic instrument 2. The refrigerant recovery
machine 1 has mounted therein a refrigerant pipe system 11, a
compressor pipe line 12 and a condenser pipe line 13. The
refrigerant pipe system 11 comprises an input pipe 111 and an
output pipe 112. Valve switches 14 are respectively in the input
pipe 111 and the output pipe 112 for controlling closing/opening of
the respective passages. The electronic instrument 2 comprises a
control unit 21, a LCD (Liquid Crystal Display) device 22, a
pressure sensor unit 23, a temperature sensor unit 24, operating
buttons 25 and an alarm 26. The LCD (Liquid Crystal Display) device
22, the pressure sensor unit 23, the temperature sensor unit 24,
the operating buttons 25 and the alarm 26 are respectively
electrically connected to the control unit 21.
[0013] The control unit 21 comprises a microprocessor 211, a
multiplexer 212 and an operation amplifier 213. The microprocessor
211 has set therein pressure threshold limit values and a
temperature threshold limit value. The pressure threshold limit
values include a high-pressure threshold limit value and a negative
pressure (vacuum) threshold limit value.
[0014] The LCD device 22 is controllable by the control unit 21 and
adapted to display status data of the refrigerant recovery machine
1 transmitted by the control unit 21.
[0015] The pressure sensor unit 23 comprises an input pipe pressure
sensor 231 adapted to detect the pressure in the input pipe 111 of
the refrigerant pipe system 11 of the refrigerant recovery machine
1, and an output pipe pressure sensor 232 adapted to detect the
pressure in the output pipe 112 of the refrigerant pipe system 11
of the refrigerant recovery machine 1.
[0016] The temperature sensor unit 24 comprises an input pipe
temperature sensor 241 adapted to detect the temperature in the
input pipe 111 of the refrigerant pipe system 11 of the refrigerant
recovery machine 1, an output pipe temperature sensor 242 adapted
to detect the temperature in the output pipe 112 of the refrigerant
pipe system 11 of the refrigerant recovery machine 1, a compressor
pipe line temperature sensor 243 adapted to detect the temperature
in the compressor pipe line 12 and a condenser pipe line
temperature sensor 244 adapted to detect the temperature in the
condenser pipe line 13.
[0017] The operating buttons 25 are operable by the user to control
the control unit 21 in controlling the operation of the refrigerant
recovery machine 1 and the display mode of the LCD device 22.
[0018] The alarm 26 is controlled by the control unit 21. When the
refrigerant recovery machine 1 is abnormal or fails, the alarm 26
gives a warning signal. The alarm 26 can be a buzzer or light
source.
[0019] When using the refrigerant recovery machine 1 to draw in the
refrigerant from the system main unit, switch off the valve
switches 14 of the refrigerant recovery machine 1 to close the
input pipe 111 and the temperature in the output pipe 112, and then
connect the input pipe 111 to the system main unit and the output
pipe 112 to a refrigerant storage tank. At this time, the user can
operate the operation buttons 25 to start the refrigerant recovery
machine 1 and then switch on the valve switches 14 of the
refrigerant recovery machine 1 to open the input pipe 111 and the
temperature in the output pipe 112. During operation of the
refrigerant recovery machine 1, the refrigerant of the system main
unit is drawn by the refrigerant recovery machine 1 into the input
pipe 111 to flow through the compressor pipe line 12 and the
condenser pipe line 13 toward the refrigerant storage tank via the
output pipe 112. When the refrigerant recovery machine 1 is drawing
the refrigerant out of the system main unit toward the refrigerant
storage tank, the input pipe pressure sensor 231 and the output
pipe pressure sensor 232 keep detecting the pressure in the input
pipe 111 and the pressure in the output pipe 112 respectively and
provides the respective detected pressure values to the control
unit 21 for comparison with the set pressure threshold limit
values. Because the refrigerant is being drawn out of the system
main unit into the input pipe 111, the inside pressure of the
system main unit is continuously lowered, producing a vacuum. Thus,
when the control unit 21 receives a pressure value from the input
pipe pressure sensor 231, the microprocessor 211 compares the
pressure value with the set negative pressure (vacuum) threshold
limit value. When the detected pressure value is equal to or below
the set negative pressure (vacuum) threshold limit value, it means
the refrigerant has been completely drawn out of the system main
unit. At this time, the control unit 21 drives the LCD device 22 to
display the message and the alarm 26 to give an alarm signal, and
then stops the refrigerant recovery machine 1. Because the output
pipe 112 delivers the refrigerant to the refrigerant storage tank,
the pressure in the refrigerant storage tank will increase
gradually. When the control unit 21 receives a pressure value from
the output pipe pressure sensor 232, the microprocessor 211
compares the pressure value with the set high pressure threshold
limit value. When the detected pressure value is equal to or above
the set high pressure threshold limit value, it means the storage
amount of the refrigerant in the refrigerant storage tank has
reached to the desired level. At this time, the control unit 21
stops the operation of the refrigerant recovery machine 1 (if the
refrigerant recovery machine 1 is not stopped at this time, the
refrigerant storage tank may be unable to sustain the pressure and
may break or the collected refrigerant may leaks through the relief
valve to pollute the air) and drives the LCD device 22 to display
the message and the alarm 26 to give an alarm signal. After
replacement of the refrigerant storage tank that is fully filled up
with the refrigerant with an empty refrigerant storage tank by the
user, the pressure detected by the output pipe pressure sensor 232
will be below the set high pressure threshold limit value, enabling
the control unit 21 to start the refrigerant recovery machine 1 and
to draw the refrigerant out of the system main unit again. The user
can also operate the operation buttons 25 to start the refrigerant
recovery machine 1 after replacement of the refrigerant storage
tank that is fully filled up with the refrigerant with an empty
refrigerant storage tank. During operation of the refrigerant
recovery machine 1, the input pipe temperature sensor 241, output
pipe temperature sensor 242, compressor pipe line temperature
sensor 243 and condenser pipe line temperature sensor 244 of the
temperature sensor unit 24 detect the temperature in the input pipe
111 and output pipe 112 of the refrigerant pipe system 11 of the
refrigerant recovery machine 1 and the temperature in the
compressor pipe line 12 and the temperature in the condenser pipe
line 13 respectively and transmit the respective detected
temperature values to the control unit 21 so that the
microprocessor 211 of the control unit 21 compares the received
temperature values with the set temperature threshold limit value.
When the detected temperature value from the input pipe temperature
sensor 241, the output pipe temperature sensor 242, the compressor
pipe line temperature sensor 243 or the condenser pipe line
temperature sensor 244 is equal to or below the set temperature
threshold limit value, it means the corresponding pipe line is a
frozen status to block transfer of the refrigerant. Therefore, the
control unit 21 stops the refrigerant recovery machine 1 and drives
the LCD device 22 to display the message and the alarm 26 to give
an alarm signal when the detected temperature value from the input
pipe temperature sensor 241, the output pipe temperature sensor
242, the compressor pipe line temperature sensor 243 or the
condenser pipe line temperature sensor 244 is equal to or below the
set temperature threshold limit value. After the trouble is
eliminated and the temperature resumes normal, the control unit 21
starts the refrigerant recovery machine 1 again. Further, the
microprocessor 211 has set therein an abnormality detection
temperature value. When the detected temperature value from the
compressor pipe line temperature sensor 243 or the condenser pipe
line temperature sensor 244 reaches the set abnormality detection
temperature value, it means the compressor pipe line 12 or the
condenser pipe line 13 has broken or there is a refrigerant
leakage. At this time, the control unit 21 stops the refrigerant
recovery machine 1 and drives the LCD device 22 to display the
message and the alarm 26 to give an alarm signal.
[0020] In conclusion, the invention utilizes the pressure sensor
unit 23 and temperature sensor unit 24 of the electronic instrument
2 to detect the refrigerant drawing status and the control unit 21
to control the operation of the refrigerant recovery machine 1
subject to the results of comparison of the detected values from
the pressure sensor unit 23 and the temperature sensor unit 24 with
predetermined pressure and temperature threshold limit values,
eliminating the use of high-pressure mechanical type and mechanical
vacuum type safety pressure switch means as seen in the prior art
techniques, reducing the cost and dimension of the refrigerant
recovery machine 1.
[0021] Although a particular embodiment of the invention has been
described in detail for purposes of illustration, various
modifications and enhancements may be made without departing from
the spirit and scope of the invention. Accordingly, the invention
is not to be limited except as by the appended claims.
* * * * *