U.S. patent application number 10/938647 was filed with the patent office on 2005-03-17 for refrigerant leakage sensing system and method.
This patent application is currently assigned to LG Electronics Inc.. Invention is credited to Jeong, Jin-Ho.
Application Number | 20050056031 10/938647 |
Document ID | / |
Family ID | 33308407 |
Filed Date | 2005-03-17 |
United States Patent
Application |
20050056031 |
Kind Code |
A1 |
Jeong, Jin-Ho |
March 17, 2005 |
Refrigerant leakage sensing system and method
Abstract
The present invention relates to refrigerant leakage sensing
system and method, and more particularly, to refrigerant leakage
sensing system and method for sensing the occurrence or not of
refrigerant leakage. In the present invention, temperature sensors
are mounted at inlet and outlet sides of an evaporator,
respectively. When a difference between the temperatures sensed by
the temperature sensors becomes above a predetermined value, a
control unit determines that the refrigerant leaks. Then, the
refrigerant leakage is displayed to a user. Accordingly, the
present invention makes it possible to cope with the problem caused
from the occurrence of the refrigerant leakage and to exchange
parts such as refrigerant pipes with new ones at an early stage by
automatically sensing the refrigerant leakage with low cost.
Inventors: |
Jeong, Jin-Ho; (Busan City,
KR) |
Correspondence
Address: |
FLESHNER & KIM, LLP
P.O. BOX 221200
CHANTILLY
VA
20153
US
|
Assignee: |
LG Electronics Inc.
|
Family ID: |
33308407 |
Appl. No.: |
10/938647 |
Filed: |
September 13, 2004 |
Current U.S.
Class: |
62/126 ;
62/149 |
Current CPC
Class: |
F25B 2700/21174
20130101; G01M 3/002 20130101; F25B 2700/21175 20130101; F25D
2400/04 20130101; F25B 49/005 20130101; F25B 2500/222 20130101 |
Class at
Publication: |
062/126 ;
062/149 |
International
Class: |
F25B 049/00; F25B
045/00; F25D 021/06 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 17, 2003 |
KR |
2003-0064577 |
Claims
What is claimed is:
1. A refrigerant leakage sensing system for use in a cooling cycle
including a compressor, a condenser and an evaporator, comprising:
a first temperature sensor for sensing a temperature of the
refrigerant flowing into the evaporator; a second temperature
sensor for sensing a temperature of the refrigerant discharging
from the evaporator; a control unit for calculating a difference
between the temperatures sensed by the first and second temperature
sensors and determining whether the refrigerant leakage has
occurred or not; and a display unit for displaying the refrigerant
leakage when the refrigerant leakage occurs under control of the
control unit.
2. A refrigerant leakage sensing method, comprising: a first
sensing step of sensing a temperature of refrigerant at an inlet
side of an evaporator; a second sensing step of sensing a
temperature of the refrigerant at an outlet side of the evaporator;
a calculating step of calculating a difference between the
temperatures sensed in the first and second sensing steps; and a
refrigerant leakage displaying step of displaying refrigerant
leakage when the temperature difference calculated in the
calculating step is greater than or equal to a predetermined
value.
3. The method as claimed in claim 2, wherein in the refrigerant
leakage displaying step, an alarm sound is outputted according to
the refrigerant leakage.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to refrigerant leakage sensing
system and method, and more particularly, to refrigerant leakage
sensing system and method for sensing the occurrence or not of
refrigerant leakage.
[0003] 2. Description of the Prior Art
[0004] Hydrocarbon-based and hybrid refrigerant and the like has
been employed as the alternative to a general refrigerant applied
to a cooling cycle. The refrigerant has explosiveness and toxicity.
Therefore, leakage of the refrigerant in a refrigerant pipe not
only deteriorates the performance of the cooling cycle but also
affects the human body adversely. Accordingly, a refrigerant
leakage sensing system is essential for sensing whether or not the
refrigerant leaks from the refrigerant pipe.
[0005] Hereinafter, a refrigerant leakage sensing system according
to a prior art will be described.
[0006] FIG. 1 shows a first embodiment for sensing refrigerant
leakage according to the prior art.
[0007] In prior art, a gas concentration sensor 20 is separately
provided in a semi-closed system as shown in the figure. The gas
concentration sensor 20 is connected to a controller 30. The gas
concentration sensor 20, as a sensor for sensing gas concentration,
senses that the concentration of toxic gas in the room increases
above the dangerous level when refrigerant in a refrigerant pipe 10
leaks into a space where a refrigerator or air conditioner is
installed.
[0008] However, it was difficult for such a conventional
refrigerant leakage sensing system to immediately sense the
refrigerant leakage caused from the occurrence of fine cracks in
the refrigerant pipe 10.
[0009] In addition, the refrigerant leakage sensing system
including such a gas concentration sensor 20 is very expensive.
Accordingly, the expensive sensing system increases cost and makes
it hard to apply such a system to electric home appliances such as
general refrigerators.
[0010] Furthermore, in such a conventional first embodiment, there
is cumbersomeness in that algorithm for sensing the gas
concentration according to the capacity of the refrigerant
pipe.
[0011] FIG. 2 shows a second embodiment for sensing refrigerant
leakage according to the prior art.
[0012] FIG. 2 illustrates a manual method for sensing the
refrigerant leakage. Referring to FIG. 2, when the refrigerant is
gradually discharged through cracks or bad welds occurring in the
refrigerant pipe 10, soap water or refrigerant reaction solution is
sprayed at a portion where it is expected for the crack to occur.
Then, at a portion where the crack occurs, bubbles of the soap
water solution are generated or the refrigerant reaction solution
indicates the existence of the crack.
[0013] However, if the crack of the refrigerant pipe is too fine or
the refrigerant is completely exhausted, the refrigerant leakage
cannot be sensed by such a manual sensing method. Further, an
inspector should manually and periodically sense the refrigerant
leakage, which is cumbersome.
SUMMARY OF THE INVENTION
[0014] Accordingly, an object of the present invention is to
provide refrigerant leakage sensing system and method for
automatically sensing the occurrence or not of refrigerant leakage
with low cost.
[0015] According to an aspect of the present invention for
achieving the objects, there is provided a refrigerant leakage
sensing system in a cooling cycle comprising a compressor, a
condenser, and an evaporator. The refrigerant leakage sensing
system comprises a first temperature sensor for sensing a
temperature of the refrigerant flowing into the evaporator; a
second temperature sensor for sensing a temperature of the
refrigerant discharging from the evaporator; a control means for
calculating a difference between the temperatures sensed by the
first and second temperature sensors and determining the occurrence
or not of refrigerant leakage; and a display unit for displaying
the refrigerant leakage when the refrigerant leakage occurs under
control of the control unit.
[0016] According to another aspect of the present invention for
achieving the objects, there is provided a refrigerant leakage
sensing method, comprising: a first sensing step of sensing a
temperature of refrigerant at an inlet side of an evaporator; a
second sensing step of sensing a temperature of the refrigerant at
an outlet side of the evaporator; a calculating step of calculating
a difference between the temperatures sensed in the first and
second sensing steps; and a refrigerant leakage displaying step of
displaying refrigerant leakage when the temperature difference
calculated in the calculating step is above a predetermined
value.
[0017] Preferably, in the refrigerant leakage displaying step, an
alarm sound is outputted when the refrigerant leakage occurs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above and other objects, features and advantages of the
present invention will become apparent from the following
description of a preferred embodiment given in conjunction with the
accompanying drawings, in which:
[0019] FIG. 1 is a view of a first embodiment for sensing
refrigerant leakage according to a prior art;
[0020] FIG. 2 is a view of a second embodiment for sensing the
refrigerant leakage according to the prior art;
[0021] FIG. 3 is a control block diagram for sensing the
refrigerant leakage according to the present invention;
[0022] FIG. 4 is a control flow chart of the operation for sensing
the refrigerant leakage according to the present invention;
[0023] FIG. 5 is a view of an embodiment for sensing the
refrigerant leakage according to the present invention;
[0024] FIG. 6a is a view showing a normal state of inflow and
outflow of the refrigerant;
[0025] FIG. 6b is a view showing a difference between temperatures
at inlet and outlet of an evaporator according to the normal state
of the inflow and outflow of the refrigerant;
[0026] FIG. 7a is a view showing a state of the inflow and outflow
of the refrigerant when the refrigerant leaks; and
[0027] FIG. 7b is a view showing a difference between temperatures
at the inlet and outlet of an evaporator according to the state of
the inflow and outflow of the refrigerant when the refrigerant
leaks.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] Hereinafter, refrigerant leakage sensing system and method
according to the present invention will be described in detail.
[0029] FIG. 3 is a control block diagram for sensing refrigerant
leakage according to the present invention.
[0030] A refrigerant leakage sensing system of the present
invention comprises a power supply 220 for supplying a refrigerator
main body with power, a first temperature sensor 120 for measuring
a refrigerant temperature at an inlet side of an evaporator, a
second temperature sensor 130 for measuring a refrigerant
temperature at an outlet side of the evaporator, a microcontroller
200 for controlling the operation of the refrigerator, calculating
a difference between the temperatures measured by the first and
second temperature sensors 120 and 130, comparing the difference
with a reference value, and determining the occurrence or not of
the refrigerant leakage, and a display 210 for displaying the
refrigerant leakage.
[0031] Referring to FIGS. 4 and 5, the operation of the refrigerant
leakage sensing system will be described as follows.
[0032] FIG. 4 is a control flow chart of the operation for sensing
the refrigerant leakage according to the present invention. FIG. 5
is a view of an embodiment for sensing the refrigerant leakage
according to the present invention.
[0033] As shown in FIG. 5, the evaporator of the refrigerator is
provided in a freezing chamber. Cold air supplied to the freezing
chamber circulates in the freezing chamber and is then sucked
through a return duct 150. The freezing chamber is provided with a
fan motor 110 for controlling a fan to be driven so that the heat
exchanged cold air can be fast blown into the freezing chamber.
[0034] In the meantime, the cold air which is subjected to heat
exchange through the evaporator in the freezing chamber is supplied
into a refrigerating chamber. That is, the cold air generated from
the evaporator of the freezing chamber is supplied to the
refrigerating chamber through a duct 140 for cold air flow formed
from the freezing chamber to the refrigerating chamber. The cold
air supplied to the refrigerating chamber circulates in the
refrigerating chamber, and then, is sucked through return the duct
150.
[0035] The inlet side of the refrigerant pipe of the evaporator 100
attached to a rear face of the freezing chamber is mounted with the
first temperature sensor 120. The outlet side of the refrigerant
pipe of the evaporator 100 is mounted with the second temperature
sensor 130. The first and second temperature sensors 120 and 130
mounted as mentioned above sense the temperatures at the inlet and
outlet sides of the refrigerant pipe (steps 210 and 220). The
temperatures sensed through the first and second temperature
sensors 120 and 130 are transmitted to the microcontroller 200.
Accordingly, the microcontroller 200 calculates the difference
between the transmitted temperatures (step 230).
[0036] In the meantime, a reference value for determining the
occurrence or not of the refrigerant leakage of the refrigerant
pipe according to the difference between the temperatures sensed by
the first and second temperature sensors 120 and 130 is set in the
microcontroller 200.
[0037] Accordingly, if the difference between the temperatures
sensed by the first and second temperature sensors 120 and 130 is
below the reference value, the microcontroller 200 determines that
the refrigerant pipe of the evaporator 100 is in normal state.
[0038] However, if the difference between the temperatures sensed
by the first and second temperature sensors 120 and 130 is above
the reference value (step 240), the microcontroller 200 determines
that the refrigerant leakage occurs from the refrigerant pipe of
the evaporator 100.
[0039] Accordingly, the occurrence or not of the refrigerant
leakage is displayed through the display (step 250), which is
confirmed by a user such that the user can immediately cope with
the refrigerant leakage (e.g., exchange parts such as the
refrigerant pipes with new ones).
[0040] When the refrigerant leakage occurs, although the occurrence
of the refrigerant leakage is displayed through the display 210 in
the embodiment of the present invention, an alarm sound may be
outputted according to the refrigerant leakage by providing an
alarm (not shown) as another example of the present invention.
[0041] FIG. 6a is a view showing a normal state of the inflow and
outflow of the refrigerant. FIG. 6b is a view showing a difference
between the temperatures at the inlet and outlet of the evaporator
according to the normal state of the inflow and outflow of the
refrigerant.
[0042] FIG. 6a shows an evaporation state of the refrigerant when
the inflow and outflow of the refrigerant normally progress without
the refrigerant leakage. The first temperature sensor 120 provided
at the inlet side of the evaporator 100 and the second temperature
sensor 130 provided at the outlet side of the evaporator 100 sense
the temperatures, respectively. In the state without the
refrigerant leakage, the temperatures at the inlet and outlet sides
of the evaporator 100 are expressed as shown in FIG. 6b. That is,
the difference between the temperatures of the refrigerant flowing
into the evaporator 100 and the refrigerant discharged from the
evaporator 100 hardly exists and is constantly maintained.
[0043] FIG. 7a is a view showing a state of the inflow and outflow
of the refrigerant when the refrigerant leaks. FIG. 7b is a view
showing a difference between the temperatures at the inlet and
outlet of the evaporator according to the state of the inflow and
outflow of the refrigerant when the refrigerant leaks.
[0044] As shown in FIG. 7a, if the refrigerant leakage occurs, an
amount of the refrigerant in the evaporator 100 is reduced.
Therefore, an evaporation point of the refrigerant of the
evaporator 100 becomes relatively early as compared with the normal
state. That is, the refrigerant is completely evaporated at a point
B before a point A where the refrigerant is evaporated in the
normal state (FIG. 6a) as shown in the FIG. 7a. Accordingly, the
refrigerant temperature at the outlet side of the evaporator 100
becomes too high, and finally, the difference between the
temperatures at the inlet and outlet sides of the evaporator 100
becomes large.
[0045] That is, as shown in FIG. 7b, the difference between the
temperatures sensed through the first temperature sensor 120
provided at the inlet side of the evaporator 100 and the second
temperature sensor 130 provided at the outlet side of the
evaporator 100 is greater than a certain value (for example, about
5.degree. C. in the embodiment of the present invention) when the
refrigerant leaks.
[0046] The first and second temperature sensors 120 and 130
employed in the present invention also function as defrosting
temperature sensors.
[0047] According to the refrigerant leakage sensing system and
method of the present invention, the following advantages can be
expected.
[0048] According to the present invention, it is possible to
determine the occurrence or not of the refrigerant leakage
according to the difference between the temperatures sensed through
the temperature sensors provided at the inlet and outlet sides of
the evaporator, without sensing the occurrence or not of the
refrigerant leakage by using an additional expensive apparatus or
by manual inspection as the prior art.
[0049] That is, according to the present invention, the evaporation
point of the refrigerant in the evaporator becomes early when the
refrigerant leaks, and thus, the temperature at the outlet side of
evaporator is increased. Then, since the difference between the
temperatures at the inlet and outlet sides of the evaporator
becomes large, the occurrence or not of the refrigerant leakage can
be determined. Accordingly, the present invention makes it possible
to automatically sense the refrigerant leakage with low cost.
[0050] As described above, in the present invention, the respective
temperature sensors are provided at the inlet and outlet sides of
the evaporator in order to sense the refrigerant leakage in the
refrigerator. Then, there is a fundamental feature of the present
invention in that whether or not the refrigerant leakage progresses
is determined according to the difference between the temperatures
sensed through the temperature sensors.
[0051] The scope of the present invention is not limited to the
embodiment described and illustrated above but is defined by the
appended claims. It will be apparent that those skilled in the art
can make various modifications and changes thereto within the scope
of the invention defined by the claims. Therefore, the true scope
of the present invention should be defined by the technical spirit
of the appended claims.
* * * * *