U.S. patent application number 10/586130 was filed with the patent office on 2007-07-12 for refrigeration system.
Invention is credited to Masaaki Takegami, Kenji Tanimoto.
Application Number | 20070157650 10/586130 |
Document ID | / |
Family ID | 36336530 |
Filed Date | 2007-07-12 |
United States Patent
Application |
20070157650 |
Kind Code |
A1 |
Takegami; Masaaki ; et
al. |
July 12, 2007 |
Refrigeration system
Abstract
A refrigeration system includes a controller (90) for
controlling operation restart after a breaker trips owing to
failure in electric systems for refrigeration system components.
The controller (90) includes a sequential startup section (91) for,
upon the operation restart, sequentially starting up target
compressors (2A, 2B, 2C) and outdoor fans (F1, F2) previously
selected from among the refrigeration system components, and
failure processing section (92) for, if the breaker trips again
during the sequential startup of the target compressors and outdoor
fans, excluding the compressor or outdoor fan (2A, . . . ) supplied
with electric power just before the breaker's trip from the target
refrigeration system components to be started up by the sequential
startup section (91). Thus, a failed component is identified by the
failure processing section (92) and only the normal components,
leaving out the failed component, are then started up, thereby
resuming the operation.
Inventors: |
Takegami; Masaaki; (Osaka,
JP) ; Tanimoto; Kenji; (Osaka, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
36336530 |
Appl. No.: |
10/586130 |
Filed: |
November 10, 2005 |
PCT Filed: |
November 10, 2005 |
PCT NO: |
PCT/JP05/20603 |
371 Date: |
July 17, 2006 |
Current U.S.
Class: |
62/230 |
Current CPC
Class: |
F25B 13/00 20130101;
F25B 2500/26 20130101; F25B 49/025 20130101; F25B 2400/075
20130101; F25B 2400/22 20130101; F25B 2500/06 20130101 |
Class at
Publication: |
062/230 |
International
Class: |
F25B 49/00 20060101
F25B049/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 10, 2004 |
JP |
2004-326509 |
Claims
1. A refrigeration system for performing a refrigeration operation
in which electric systems of refrigeration system components (2A,
2B, . . . ) are supplied with electric power from a power supply
through a breaker, the refrigeration system comprising: sequential
startup means (91) for, upon operation restart after the breaker
trips owing to failure in the electric systems, sequentially
starting up target refrigeration system components (2A, 2B, . . . )
previously selected from among the refrigeration system components;
and failure processing means (92) for, if the breaker trips again
owing to failure in the electric systems during the sequential
startup of the target refrigeration system components through the
sequential startup means (91), excluding the refrigeration system
component (2A, 2B, . . . ) supplied with electric power just before
the occurrence of the failure from the target refrigeration system
components to be started up by the sequential startup means
(91).
2. The refrigeration system of claim 1, further comprising
transition means (93) for, when the target refrigeration system
components (2A, 2B, . . . ) to be started up by the sequential
startup means (91) are all normally started up, making a transition
to a normal operation while holding in a halted state the
refrigeration system component (2A, 2B, . . . ) excluded from the
target refrigeration system components by the failure processing
means (92).
3. The refrigeration system of claim 1, wherein the target
refrigeration system components to be sequentially started up by
the sequential startup means (91) are a plurality of compressors
(2A, 2B, 2C).
4. The refrigeration system of claim 1, wherein the target
refrigeration system components to be sequentially started up by
the sequential startup means (91) are a plurality of compressors
(2A, 2B, 2C) and a plurality of fans (F1, F2).
Description
TECHNICAL FIELD
[0001] This invention relates to refrigeration systems and
particularly relates to controlling restart of refrigeration system
components when they are halted owing to failure in their electric
systems.
BACKGROUND ART
[0002] There have been known refrigeration systems including a
refrigerant circuit that operates in a refrigeration cycle using a
plurality of compressors (see, for example, Patent document 1). The
refrigeration system in Patent document 1 is formed with an
air-conditioning refrigerant circuit for cooling and heating a room
and a chilling/freezing refrigerant circuit for cooling the insides
of cold storages for foods or the like and these refrigerant
circuits are formed by connecting three compressors, condensers and
evaporators. In the above refrigeration system, principally, one of
the three compressors is used for air conditioning, the remaining
two are used for chilling and freezing and a refrigeration
operation is run by circulating refrigerant through each of the
refrigerant circuits.
Patent document 1: Unexamined Japanese Patent Publication No.
2003-75022
--Problems to Be Solved--
[0003] The refrigeration system in Patent document 1, however,
takes no measure to cope with failure owing to which a breaker
trips. The refrigeration system has a problem that if, for example,
one or two of the three compressors cause failure in their electric
systems to halt the refrigeration operation, taking no measure to
cope with it prevents the resumption (restart) of the refrigeration
operation. Specifically, during refrigeration operation, the
electric system of any one of the compressors may cause failure
such as electric leakage so that power supply is shut off to halt
the operation. In such a case, however, since it is not known
exactly which of the three compressors have a failed electric
system, simple restart of the compressors leads to power supply
being shut off again owing to the failed electric system.
Therefore, so long as the compressor having its electric system
failed is removed, the above refrigeration system cannot restart
the operation.
[0004] The present invention has been made in view of the foregoing
points and its object is to at least resume (restart) the
refrigeration operation after its halt as a result of shutoff of
power supply due to failure in one or some of electric systems of
refrigeration system components by identifying the refrigeration
system components having their electric systems failed and
inhibiting their restart.
DISCLOSURE OF THE INVENTION
[0005] Solutions taken by the present invention are as follows.
[0006] A first solution is directed to a refrigeration system for
performing a refrigeration operation in which electric systems of
refrigeration system components (2A, 2B, . . . ) are supplied with
electric power from a power supply through a breaker. Further, the
refrigeration system of this solution comprises sequential startup
means (91) for, upon operation restart after the breaker trips
owing to failure in the electric systems, sequentially starting up
target refrigeration system components (2A, 2B, . . . ) previously
selected from among the refrigeration system components.
Furthermore, the refrigeration system of the present invention
comprises failure processing means (92) for, if the breaker trips
again owing to failure in the electric systems during the
sequential startup of the target refrigeration system components
through the sequential startup means (91), excluding the
refrigeration system component (2A, 2B, . . . ) supplied with
electric power just before the occurrence of the failure from the
target refrigeration system components to be started up by the
sequential startup means (91).
[0007] In the above solution, if one or some of the refrigeration
system components cause failure in their electric systems to halt
the refrigeration operation, the refrigeration system components
having their electric systems failed are identified.
[0008] Specifically, for example, suppose that electric systems of
a plurality of refrigeration system components such compressors
cause failure, such as electric leakage or disconnection, so that
the breaker trips to abnormally halt the refrigeration operation.
First, the sequential startup means (91) allows electric power to
be sequentially supplied to the previously selected target
refrigeration system components (for example, a plurality of
compressors) to start up them. In this case, if the first
compressor normally starts up through power supply, then the second
compressor is supplied with power. Next, if the second compressor
does not normally start up and the breaker trips again, the failure
processing means (92) excludes the second compressor from the
target refrigeration system components to be started up by the
sequential startup means (91). In other words, the second
compressor is identified as a refrigeration system component having
caused failure in its electric system (as a failed component) and
the other compressors other than the second compressor are
sequentially started up again as the target refrigeration system
components. By repeating the above startup process, all of failed
components having their electric systems failed are identified from
among the previously selected target refrigeration system
components. Then, the refrigeration operation is normally resumed
as by the removal of the identified failed components.
[0009] A second solution is directed to the above first solution,
wherein the registration system further comprises transition means
(93) for, when the target refrigeration system components (2A, 2B,
. . . ) to be started up by the sequential startup means (91) are
all normally started up, making a transition to a normal operation
while holding in a halted state the refrigeration system component
(2A, 2B, . . . ) excluded from the target refrigeration system
components by the failure processing means (92).
[0010] In the above solution, when all the target refrigeration
system components (2A, 2B, . . . ) to be started up by the
sequential startup means (91) normally start up, i.e., when all of
failed components are identified, the normal operation is performed
by starting up only the normal refrigeration system components
while supplying the failed components with no power to hold them in
a halted state. Thus, the refrigeration operation is surely
resumed.
[0011] A third solution is directed to the first solution, wherein
the target refrigeration system components to be sequentially
started up by the sequential startup means (91) are a plurality of
compressors (2A, 2B, 2C).
[0012] In the above solution, in the case where a refrigeration
operation using, for example, three compressors (2A, 2B, 2C) is
abnormally halted and, for example, two compressors (2B, 2C) are
identified as failed components by the failure processing means
(92), only a single compressor (2A), leaving out the two failed
components, is started up to resume the refrigeration operation.
Thus, since at least the normal compressor (2A) is surely started
up, the operation is surely resumed.
[0013] A fourth solution is directed to the first solution, wherein
the target refrigeration system components to be sequentially
started up by the sequential startup means (91) are a plurality of
compressors (2A, 2B, 2C) and a plurality of fans (F1, F2).
[0014] In the above solution, in the case where a refrigeration
operation using, for example, three compressors (2A, 2B, 2C) and
two outdoor fans (F1, F2) is abnormally halted and, for example,
two compressors (2B, 2C) and one outdoor fan (F2) are identified as
failed components by the failure processing means (92), only a
single compressor (2A) and a single outdoor fan (F1), leaving out
those failed components, are started up to resume the refrigeration
operation. Thus, since at least the normal compressor (2A) and the
normal outdoor fan (F1) are surely started up, the operation is
surely resumed.
--Effects--
[0015] According to the first solution, if the breaker (81) trips
owing to failure in the electric system of a refrigeration system
component to abnormally halt the operation, the previously selected
target refrigeration system components (2A, 2B, . . . ) are
sequentially started up. If during the sequential startup the
breaker (81) trips again owing to failure in the electric system,
the refrigeration system component supplied with electric power
just before the trip is not started up anymore. Therefore, from
among the target refrigeration system components (2A, 2B, . . . ),
the component having caused failure in its electric system can be
surely identified as a failed component. Consequently, if the
refrigeration system component identified as a failed component is
supplied with no electric power, in other words, if only normal
refrigeration system components, leaving out the failed component,
are supplied with electric power, the operation can surely be
resumed (restarted).
[0016] According to the second solution, if all the target
refrigeration system components (2A, 2B, . . . ) to be sequentially
started up normally start up, a transition to the normal operation
is made while the refrigeration system component excluded from the
target refrigeration system components is held halted. This avoids
that the breaker (81) trips again owing to failure in the electric
system, thereby surely resuming (restarting) the normal operation.
Therefore, though the capacity associated with the failed component
is not performed, at least the operation can be surely resumed
(restarted).
[0017] According to the third solution, a plurality of compressors
(2A, 2B, 2C) are selected as target refrigeration system components
to be sequentially started up by the sequential startup means (91).
According to the fourth solution, in addition to the plurality of
compressors (2A, 2B, 2C), a plurality of outdoor fans (F1, F2) are
selected as target refrigeration system components to be
sequentially started up by the sequential startup means (91).
Therefore, even if some of them becomes out of action owing to
failures in their electric systems, at least a normal compressor
(2A, 2B, 2C) and/or a normal outdoor fan (F1, F2) can be started
up, which ensures operation resumption.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1 is a piping diagram for a refrigeration system
according to an embodiment.
[0019] FIG. 2 is a block diagram showing a power supply circuit
according to the embodiment.
[0020] FIG. 3 is a piping diagram showing a refrigerant flow during
a cooling and refrigeration operation of the refrigeration
system.
[0021] FIG. 4 is a piping diagram showing a refrigerant flow during
a heating and refrigeration operation of the refrigeration
system.
[0022] FIG. 5 is a flowchart showing the control on operation
resumption according to Embodiment 1.
[0023] FIG. 6 is a characteristic diagram (first one) showing the
relation between power distribution state and failure flag
according to Embodiment 1.
[0024] FIG. 7 is a characteristic diagram (second one) showing the
relation between power distribution state and failure flag
according to Embodiment 1.
[0025] FIG. 8 is a flowchart showing the control on operation
resumption according to Embodiment 2.
EXPLANATION OF REFERENCE CHARACTERS
[0026] 1 refrigeration system [0027] 2A inverter compressor
(refrigeration system component) [0028] 2B first non-inverter
compressor (refrigeration system component) [0029] 2C second
non-inverter compressor (refrigeration system component) [0030] F1
first outdoor fan (refrigeration system component) [0031] F2 second
outdoor fan (refrigeration system component) [0032] 91 sequential
startup section (sequential startup means) [0033] 92 failure
processing section (failure processing means) [0034] 93 operation
transition section (operation transition means)
BEST MODE FOR CARRYING OUT THE INVENTION
[0035] Embodiments of the present invention will be described below
in detail with reference to the drawings.
Embodiment 1 of the Invention
[0036] As shown in FIG. 1, a refrigeration system (1) according to
Embodiment 1 is a system installed in a convenience store for the
purpose of cooling a cold storage display case and a freezer
display case and cooling/heating the store.
[0037] The refrigeration system (1) comprises an outdoor unit (1A),
an indoor unit (1B), a chilling unit (1C) and a freezing unit (1D)
and includes a refrigerant circuit (1E) for operating in a vapor
compression refrigeration cycle. The refrigerant circuit (1E)
comprises an air-conditioning system including the indoor unit (1B)
and a cooling system including the chilling unit (1C) and the
freezing unit (1D). Further, the refrigerant circuit (1E) is
configured to switch between a cooling cycle and a heating
cycle.
[0038] The indoor unit (1B) is placed, for example, in a selling
space, to cool and heat the store. The chilling unit (1C) is placed
in the cold storage display case to cool the air in the display
case. The freezing unit (1D) is placed in the freezer display case
to cool the air in the display case.
[0039] <Outdoor Unit>
[0040] The outdoor unit (1A) includes three compressors (2A, 2B,
2C) that are compression mechanisms, three four-way selector valves
(3A, 3B, 3C) that are flow channel selectors, and an outdoor heat
exchanger (4) that is a heat-source side heat exchanger.
[0041] The three compressors (2A, 2B, 2C) are an inverter
compressor (2A) as a first compressor, a first non-inverter
compressor (2B) as a second compressor, and a second non-inverter
compressor (2C) as a third compressor. Each of these compressors is
formed of a hermetic, high-pressure dome type scroll compressor.
The inverter compressor (2A) is a variable capacity compressor in
which a motor is controlled by an inverter to make the capacity
stepwise or continuously variable. The first non-inverter
compressor (2B) and second non-inverter compressor (2C) are fixed
capacity compressors in which a motor is driven at a constant
rotation number.
[0042] Discharge pipes (5a, 5b, 5c) for the inverter compressor
(2A), the first non-inverter compressor (2B) and the second
non-inverter compressor (2C) are connected to a common
high-pressure gas pipe (8), and the high-pressure gas pipe (8) is
connected to the first port of the first four-way selector valve
(3A). The discharge pipe (5b) for the first non-inverter compressor
(2B) and the discharge pipe (5c) for the second non-inverter
compressor (2C) are provided with check valves (7), respectively.
The high-pressure gas pipe (8) is provided with an oil separator
(30).
[0043] The outdoor heat exchanger (4) is connected at one end, a
gas-side end, through an outdoor gas pipe (9) to the third port of
the first four-way selector valve (3A) and connected at the other
end, a liquid-side end, to one end of an outdoor liquid pipe (10)
that is a liquid line. The outdoor liquid pipe (10) includes a
receiver (14) disposed partway therealong to store liquid
refrigerant and is connected at the other end through a shut-off
valve (20) to a connecting liquid pipe (11) disposed outside the
outdoor unit (1A). The outdoor liquid pipe (10) also includes a
check valve (7) disposed upstream of the receiver (14) to allow
only a refrigerant flow toward the receiver (14) and a check valve
(7) disposed downstream of the receiver (14) to allow only a
refrigerant flow from the receiver (14) toward a shut-off valve
(40).
[0044] The outdoor heat exchanger (4) is formed of, for example, a
cross-fin type fin-and-tube heat exchanger. Disposed close to the
outdoor heat exchanger (4) are two outdoor fans (F1, F2) that are
heat-source fans.
[0045] The fourth port of the first four-way selector valve (3A) is
connected via a shut-off valve (20) to a first connecting gas pipe
(17) disposed outside the outdoor unit (1A), and the second port
thereof is connected through a connecting pipe (18) to the fourth
port of the second four-way selector valve (3B). The first port of
the second four-way selector valve (3B) is connected through an
auxiliary gas pipe (19) to the discharge pipe (5c) for the second
non-inverter compressor (2C). The second port of the second
four-way selector valve (3B) is connected to a suction pipe (6c)
for the second non-inverter compressor (2C). The third port of the
second four-way selector valve (3B) is a blocked port. Therefore,
the second four-way selector valve (3B) may be replaced with a
three-way selector valve having three ports.
[0046] The first four-way selector valve (3A) is configured to
switch between a first position (the position shown in the solid
lines in FIG. 1) in which the high-pressure gas pipe (8) is
communicated with the outdoor gas pipe (9) and the connecting pipe
(18) is communicated with the first connecting gas pipe (17) and a
second position (the position shown in the broken lines in FIG. 1)
in which the high-pressure gas pipe (8) is communicated with the
first connecting gas pipe (17) and the connecting pipe (18) is
communicated with the outdoor gas pipe (9). On the other hand, the
second four-way selector valve (3B) is configured to switch between
a first position (the position shown in the solid lines in FIG. 1)
in which the auxiliary gas pipe (19) is communicated with the
blocked port and the connecting pipe (18) is communicated with the
suction pipe (6c) for the second non-inverter compressor (2C) and a
second position (the position shown in the broken lines in FIG. 1)
in which the auxiliary gas pipe (19) is communicated with the
connecting pipe (18) and the suction pipe (6c) is communicated with
the blocked port.
[0047] A suction pipe (6a) for the inverter compressor (2A) is
connected via a shut-off valve (20) to a second connecting gas pipe
(15) disposed outside the outdoor unit (1A). A suction pipe (6b)
for the first non-inverter compressor (2B) is connected to the
third four-way selector valve (3C) and configured to be
communicated with either the suction pipe (6a) for the inverter
compressor (2A) or the suction pipe (6c) for the second
non-inverter compressor (2C).
[0048] More specifically, the suction pipe (6a) for the inverter
compressor (2A) is connected through a branch pipe (6d) to the
first port of the third four-way selector valve (3C). The suction
pipe (6b) for the first non-inverter compressor (2B) is connected
to the second port (P2) of the third four-way selector valve (3C).
The suction pipe (6c) for the second non-inverter compressor (2C)
is connected through a branch pipe (6e) to the third port (P3) of
the third four-way selector valve (3C). The fourth port of the
third four-way selector valve (3C) is connected to a branch pipe
(28a) branched from the later-described gas vent pipe (28)
extending from the receiver (14). The branch pipes (6d, 6e) are
provided with check valves (7), one for each branch pipe, and each
check valve allows a refrigerant flow toward the third four-way
selector valve (3C).
[0049] The third four-way selector valve (3C) is configured to
switch between a first position (the position shown in the solid
lines in FIG. 1) in which the suction pipe (6a) for the inverter
compressor (2A) is communicated with the suction pipe (6b) for the
first non-inverter compressor (2B) and the suction pipe (6c) for
the second non-inverter compressor (2C) is communicated with the
gas vent pipe (28) and a second position (the position shown in the
broken lines in FIG. 1) in which the suction pipe (6a) for the
inverter compressor (2A) is communicated with the gas vent pipe
(28) and the suction pipes (6b, 6c) for the non-inverter
compressors (2B, 2C) are communicated with each other.
[0050] The outdoor liquid pipe (10) is connected to an auxiliary
liquid pipe (25) that bypasses the receiver (14) and the check
valve (7) upstream thereof. The auxiliary liquid pipe (25) is
provided with an outdoor expansion valve (26) that is an expansion
mechanism. The outdoor liquid pipe (10) is also connected to a
liquid branch pipe (36) having a check valve (7). One end of the
liquid branch pipe (36) is connected to the outdoor liquid pipe
(10) between the receiver (14) and the check valve (7) upstream of
the receiver (14) and the other end thereof is connected to the
outdoor liquid pipe (10) between the check valve (7) and the
shut-off valve (20) both downstream of the receiver (14). The check
valve (7) in the liquid branch pipe (36) allows only a refrigerant
flow toward the receiver (14).
[0051] Connected between the auxiliary liquid pipe (25) and the
suction pipe (6a) for the inverter compressor (2A) is a liquid
injection pipe (27) with an electronic expansion valve (29) that is
an expansion mechanism. Connected between an upper part of the
receiver (14) and the discharge pipe (5a) for the inverter
compressor (2A) is the gas vent pipe (28) with a check valve (7).
The check valve (7) of the gas vent pipe (28) is disposed between a
connection point of the branch pipe (28a) with the gas vent pipe
(28) and the receiver (14) and allows only a refrigerant flow from
the receiver (14) toward the discharge pipe (5a).
[0052] In the outdoor unit (1A), the three compressors (2A, 2B,
2C), the two outdoor fans (F1, F2), the three four-way selector
valves (3A, 3B, 3C), the outdoor expansion valve (26) and like
elements are refrigeration system components.
[0053] <Indoor Unit>
[0054] The indoor unit (1B) includes an indoor heat exchanger (41)
that is a utilization side heat exchanger and an indoor expansion
valve (42) that is an expansion mechanism. The indoor heat
exchanger (41) is connected at one end, a gas-side end, to the
first connecting gas pipe (17) and connected at the other end, a
liquid-side end, via the indoor expansion valve (42) to the
connecting liquid pipe (11). The indoor heat exchanger (41) is, for
example, a cross-fin type fin-and-tube heat exchanger. Disposed
close to the indoor heat exchanger (41) is an indoor fan (43) that
is a utilization side fan. The indoor expansion valve (42) is
formed of a motor-operated expansion valve. In the indoor unit
(1B), the indoor expansion valve (42) and the indoor fan (43) are
refrigeration system components.
[0055] <Chilling Unit>
[0056] The chilling unit (1C) includes a chilling heat exchanger
(45) that is a utilization side heat exchanger and a chilling
expansion valve (46) that is an expansion mechanism. The chilling
heat exchanger (45) is connected at one end, a liquid-side end, via
the chilling expansion valve (46) and a solenoid valve (7a) in this
order to a first branch liquid pipe (12) branched from the
connecting liquid pipe (11) and connected at the other end, a
gas-side end, to the second connecting gas pipe (15). The solenoid
valve (7a) is used to shut off the refrigerant flow during
thermo-off (downtime).
[0057] In the chilling heat exchanger (45), the refrigerant
evaporation pressure is lower than the refrigerant evaporation
pressure in the indoor heat exchanger (41). As a result, the
refrigerant evaporation temperature in the chilling heat exchanger
(45) is set at, for example, -10.degree. C. and, on the other hand,
the refrigerant evaporation temperature in the indoor heat
exchanger (41) is set at, for example, +5.degree. C. In this
manner, the refrigerant circuit (1E) constitutes a circuit for
evaporating refrigerant at different temperatures.
[0058] The chilling expansion valve (46) is a thermostatic
expansion valve and its temperature-sensing bulb is mounted to the
gas side of the chilling heat exchanger (45). Thus, the opening of
the chilling expansion valve (46) is controlled based on the
refrigerant temperature at the exit side of the chilling heat
exchanger (45). The chilling heat exchanger (45) is, for example, a
cross-fin type fin-and-tube heat exchanger. Disposed close to the
chilling heat exchanger (45) is a chilling fan (47) that is a
utilizations side fan. In the chilling unit (1C), the chilling
expansion valve (46) and chilling fan (47) are refrigeration system
components.
[0059] <Freezing Unit>
[0060] The freezing unit (1D) includes a freezing heat exchanger
(51) that is a utilization side heat exchanger, a freezing
expansion valve (52) that is an expansion mechanism, and a booster
compressor (53) that is a freezing compressor. The freezing heat
exchanger (51) is connected at one end, a liquid-side end, via the
freezing expansion valve (52) and a solenoid valve (7b) in this
order to a second branch liquid pipe (13) branched from the first
branch liquid pipe (12) and is connected at the other end, a
gas-side end, through a connecting gas pipe (54) to the suction
side of the booster compressor (53). The booster compressor (53) is
connected at the discharge side to a branch gas pipe (16) branched
from the second connecting gas pipe (15). The branch gas pipe (16)
is provided with an oil separator (55) and a check valve (7) in
order away from the booster compressor (53). The check valve (7)
allows only a refrigerant flow from the booster compressor (53)
toward the second connecting gas pipe (15). Connected between the
oil separator (55) and the connecting gas pipe (54) is an oil
return pipe (57) with a capillary tube (56).
[0061] The booster compressor (53), together with the compressors
(2A, 2B, 2C) in the outdoor unit (1A), compresses refrigerant in
two stages so that the refrigerant evaporation temperature in the
freezing heat exchanger (51) becomes lower than that in the
chilling heat exchanger (45). The refrigerant evaporation
temperature in the freezing heat exchanger (51) is set at, for
example, -35.degree. C.
[0062] The freezing expansion valve (52) is a thermostatic
expansion valve and its temperature-sensing bulb is mounted to the
gas side of the freezing heat exchanger (51). The freezing heat
exchanger (51) is, for example, a cross-fin type fin-and-tube heat
exchanger. Disposed close to the freezing heat exchanger (51) is a
freezing fan (58) that is a utilizations side fan.
[0063] Further, a bypass pipe (59) with a check valve (7) is
connected between the connecting gas pipe (54) and part of the
branch gas pipe (16) downstream of the check valve (7). The bypass
pipe (59) is configured to allow refrigerant to bypass the booster
compressor (53) and flow toward the branch gas pipe (16) during
halt of the booster compressor (53) due to failure or the like. In
the freezing unit (1D), the freezing expansion valve (52), the
freezing fan (58) and the booster compressor (53) are refrigeration
system components.
[0064] <Control System>
[0065] The refrigerant circuit (1E) is provided with various
sensors and various switches. The high-pressure gas pipe (8) in the
outdoor unit (1A) is provided with a high-pressure sensor (61) that
is a high-pressure sensing device for detecting the high pressure
of refrigerant and a discharge temperature sensor (62) that is a
temperature sensing device for detecting the discharge temperature
of refrigerant. The discharge pipe (5c) for the second non-inverter
compressor (2C) is provided with a discharge temperature sensor
(63) that is a temperature sensing device for detecting the
discharge temperature of high-pressure refrigerant. Each of the
discharge pipes (5a, 5b, 5c) for the inverter compressor (2A), the
first non-inverter compressor (2B) and the second non-inverter
compressor (2C) is provided with a pressure switch (64) that opens
when the high pressure of refrigerant reaches a predetermined
value.
[0066] The suction pipes (6a, 6c) for the inverter compressor (2A)
and the second non-inverter compressor (2C) are provided with
low-pressure sensors (65, 66), respectively, that are pressure
sensing devices for detecting the low pressure of refrigerant and
also provided with suction temperature sensors (67, 68),
respectively, that are temperature sensing devices for detecting
the suction temperature of refrigerant.
[0067] The outdoor heat exchanger (4) is provided with an outdoor
heat exchange sensor (69) that is a temperature sensing device for
detecting the evaporation temperature or the condensation
temperature of refrigerant. In addition, the outdoor unit (1A) is
provided with an outdoor air temperature sensor (70) that is a
temperature sensing device for detecting the outdoor air
temperature.
[0068] The indoor heat exchanger (41) is provided with an indoor
heat exchange sensor (71) that is a temperature sensing device for
detecting the condensation temperature or the evaporation
temperature of refrigerant and also provided at its gas side with a
gas temperature sensor (72) that is a temperature sensing device
for detecting the gas refrigerant temperature. In addition, the
indoor unit (1B) is provided with a room temperature sensor (73)
that is a temperature sensing device for detecting the room air
temperature.
[0069] The chilling unit (1C) is provided with a chilling
temperature sensor (74) that is a temperature sensing device for
detecting the temperature in the cold-storage display case. The
freezing unit (1D) is provided with a freezing temperature sensor
(75) that is a temperature sensing device for detecting the
temperature in the freezer display case. The booster compressor
(53) is provided at the discharge side with a pressure switch (64)
that opens when the discharge pressure of refrigerant reaches a
predetermined value.
[0070] The refrigeration system (1) includes a controller (90). The
controller (90) is configured to control the openings of the
outdoor expansion valve (26) and the indoor expansion valve (42)
and select ports of each four-way selector valve (3A, 3B, 3C).
[0071] As one of features of the present invention, the controller
(80) is configured to control a power supply circuit (80) for
refrigeration system components. As shown in FIG. 2, the power
supply circuit (80) is for supplying electric power to the electric
system of each refrigeration system component. Specifically, a
power supply is connected via a breaker (81) to the electric
systems of the refrigeration system components, such as the
inverter compressor (2A) and the first outdoor fan (F1). Though not
shown, the power supply is also connected via the breaker (81) to
the electric systems of the other refrigeration system components,
such as the outdoor expansion valve (26) and the four-way selector
valves (3A, 3B, 3C). The electric systems electrically conduct
through the making of associated relays (82-86), respectively. The
breaker (81) is configured to trip when failure occurs in any one
of the electric systems of refrigeration system components during
operation.
[0072] The controller (90) includes a sequential startup section
(91), a failure processing section (92) and an operation transition
section (93) and controls restart after the operation of the
refrigeration system is halted owing to failure in the electric
systems.
[0073] The sequential startup section (91) constitutes a sequential
startup means for, upon operation restart after the breaker (81)
trips owing to failure in the electric systems, sequentially
starting up target refrigeration system components (2A, 2B, . . . )
previously selected from among various refrigeration system
components. In other words, the sequential startup section (91)
sequentially makes the relays (82-86) associated with the target
refrigeration system components (2A, 2B, . . . ) to supply them
with electric power. In this embodiment, five of the various
refrigeration system components, i.e., the inverter compressor
(2A), the first non-inverter compressor (2B), the second
non-inverter compressor (2C), the first outdoor fan (F1) and the
second outdoor fan (F2), are selected as the target refrigeration
system components (hereinafter, referred to as target
components).
[0074] The failure processing section (92) constitutes failure
processing means for, if the breaker (81) trips again owing to
failure in the electric systems during the sequential startup of
the target components through the sequential startup section (91),
excluding the target component supplied with electric power just
before the occurrence of the failure from the target components to
be started up by the sequential startup section (91). Specifically,
when the breaker (81) trips during the sequential startup, the
failure processing section (92) identifies the target component
tried to be started up just before the trip as a failed component
and the sequential startup section (91) then sequentially starts up
again the target components other than the target component
identified as the failed component.
[0075] The operation transition section (93) constitutes a
transition means for, when the target components (2A, 2B, . . . )
to be started up by the sequential startup section (91) are all
normally started up, making a transition to a normal operation
while holding in a halted state the target component excluded by
the failure processing section (92), i.e., the target component
identified as a failed component. In other words, the operation
transition section (93) restarts the operation by starting up only
normal target components (2A, 2B, . . . ), leaving out the target
component identified as a failed component.
--Operational Behavior--
[0076] Next, a description will be given of the operational
behavior of the refrigeration system (1). The refrigeration system
(1) of this embodiment is configured to be switchable between a
"cooling and refrigeration operation" for concurrently performing
the room cooling of the indoor unit (1B) and the refrigeration of
the chilling unit (1C) and the freezing unit (1D) and a "heating
and refrigeration operation" for concurrently performing the room
heating of the indoor unit (1B) and the refrigeration of the
chilling unit (1C) and the freezing unit (1D).
[0077] <Cooling and Refrigeration Operation>
[0078] In the cooling and refrigeration operation, as shown in FIG.
3, the inverter compressor (2A), the first non-inverter compressor
(2B) and the second non-inverter compressor (2C) are driven and the
booster compressor (53) is also driven.
[0079] The first four-way selector valve (3A), the second four-way
selector valve (3B) and the third four-way selector valve (3C) are
set to respective first positions. The solenoid valves (7a, 7b) in
the chilling unit (1C) and the freezing unit (1D) are selected
open, while the outdoor expansion valve (26) is selected closed.
The electronic expansion valve (29) in the liquid injection pipe
(27) is controlled on its opening to supply a predetermined flow
rate of liquid refrigerant to the suction sides of the inverter
compressor (2A) and the first non-inverter compressor (2B).
[0080] Under the above conditions, flows of refrigerant discharged
from the inverter compressor (2A), the first non-inverter
compressor (2B) and the second non-inverter compressor (2C) are
combined together in the high-pressure gas pipe (8), flow through
the first four-way selector valve (3A) and then the outdoor gas
pipe (9) and condenses in the outdoor heat exchanger (4). The
liquid refrigerant obtained by the condensation flows through the
outdoor liquid pipe (10) and then the receiver (14) into the
connecting liquid pipe (11).
[0081] Part of the liquid refrigerant in the connecting liquid pipe
(11) flows into the first branch liquid pipe (12) and the rest
flows into the indoor unit (1B). In the indoor unit (1B), the
liquid refrigerant passes through the indoor expansion valve (42)
and evaporates in the indoor heat exchanger (41) to cool the store.
The gas refrigerant obtained by the evaporation flows through the
first connecting gas pipe (17) into the outdoor unit (1A), passes
through the first four-way selector valve (3A) and the second
four-way selector valve (3B), flows through the suction pipe (6c)
and then returns to the second non-inverter compressor (2C).
[0082] On the other hand, part of the liquid refrigerant having
flowed into the first branch liquid pipe (12) flows through the
second branch liquid pipe (13) and then into the freezing unit (1D)
and the rest flows into the chilling unit (1C). In the chilling
unit (1C), the liquid refrigerant passes through the chilling
expansion valve (46) and then evaporates in the chilling heat
exchanger (45) to cool the inside of the cold-storage display case.
Thereafter, the gas refrigerant obtained by the evaporation flows
through the second connecting gas pipe (15). In the freezing unit
(1D), the liquid refrigerant passes through the freezing expansion
valve (52) and then evaporates in the freezing heat exchanger (51)
to cool the inside of the freezer display case. The gas refrigerant
obtained by the evaporation is compressed by the booster compressor
(53), passes through the branch gas pipe (16) and is then combined,
in the second connecting gas pipe (15), with the gas refrigerant
coming from the chilling unit (1C). The gas refrigerant combined in
the second connecting gas pipe (15) flows into the outdoor unit
(1A), flows through the suction pipes (6a, 6b) and then returns to
the inverter compressor (2A) and the first non-inverter compressor
(2B).
[0083] <Heating and Refrigeration Operation>
[0084] In the heating and refrigeration operation, as shown in FIG.
4, the inverter compressor (2A), the first non-inverter compressor
(2B) and the second non-inverter compressor (2C) are driven and the
booster compressor (53) is also driven.
[0085] The first four-way selector valve (3A) is set to the second
position, while the second four-way selector valve (3B) and the
third four-way selector valve (3C) are set to respective first
positions. The solenoid valves (7a, 7b) in the chilling unit (1C)
and the freezing unit (1D) are selected open and the indoor
expansion valve (42) is set to its full open position. The
electronic expansion valve (29) in the liquid injection pipe (27)
is controlled to have a predetermined opening, thereby controlling
the flow rate of refrigerant.
[0086] Under the above conditions, flows of refrigerant discharged
from the inverter compressor (2A), the first non-inverter
compressor (2B) and the second non-inverter compressor (2C) flow
through the first four-way selector valve (3A) and then the first
connecting gas pipe (17) and into the indoor unit (1B). In the
indoor unit (1B), the liquid refrigerant condenses in the indoor
heat exchanger (41) to heat the store. The liquid refrigerant
obtained by the condensation flows through the connecting liquid
pipe (11) and is then divided, part thereof flowing into the first
branch liquid pipe (12) and the rest into the outdoor unit (1A).
The liquid refrigerant having flowed into the indoor unit (1B)
flows through the liquid branch pipe (36) into the receiver (14),
then passes through the outdoor expansion valve (26) and then
evaporates in the outdoor heat exchanger (4). The gas refrigerant
obtained by the evaporation flows through the outdoor gas pipe (9),
passes through the first four-way selector valve (3A) and the
second four-way selector valve (3B), flows through the suction pipe
(6c) and then returns to the second non-inverter compressor
(2C).
[0087] On the other hand, part of the liquid refrigerant having
flowed into the first branch liquid pipe (12) flows through the
second branch liquid pipe (13) and then into the freezing unit (1D)
and the rest flows into the chilling unit (1C). In the chilling
unit (1C), the liquid refrigerant evaporates in the chilling heat
exchanger (45) to cool the inside of the cold-storage display case.
In the freezing unit (1D), the liquid refrigerant evaporates in the
freezing heat exchanger (51) to cool the inside of the freezer
display case. The gas refrigerant obtained by the evaporation is
compressed by the booster compressor (53). Then, the flows of gas
refrigerant obtained by the evaporation in the chilling unit (1C)
and the freezing unit (1D) are combined in the second connecting
gas pipe (15), flow into the outdoor unit (1A) and then return to
the inverter compressor (2A) and the first non-inverter compressor
(2B).
[0088] <Control on Operation Resumption>
[0089] Next, a description is given of the control on operation
resumption in the case where during the above operation one or some
of the target components (2A, 2B, . . . ) cause failure, such as
electric leakage or short circuit, in their electric systems so
that the breaker (81) trips to abnormally halt the operation. When
the breaker (81) trips to halt the operation, as shown in FIG. 5,
the control of the controller (90) starts. Note that when the
breaker (81) trips, all the relays (82-86) associated with the
target components (2A, 2B, . . . ) are made open.
[0090] First, when in step ST1 the operator or like person turns ON
the breaker (81) of the power supply circuit (80) to distribute
electric power to the refrigeration system components, the control
proceeds to step ST2. In step ST2, the number of target components
(2A, 2B, . . . ) is identified by the sequential startup section
(91) of the controller (90). Specifically, the number of target
components is identified as five (N=5) including the inverter
compressor (2A), the first non-inverter compressor (2B), the second
non-inverter compressor (2C), the first outdoor fan (F1) and the
second outdoor fan (F2).
[0091] In step ST3, the sequential startup section (91) issues a
startup instruction to the inverter compressor (2A). Specifically,
in this embodiment, the sequential startup section (91) is
previously configured to sequentially issue startup instructions to
start up the target components in the following order: the inverter
compressor (2A) as a first (n=1) target component to be first
started up, the first non-inverter compressor (2B) as a second
(n=2) target component to be secondly started up, the second
non-inverter compressor (2C) as a third (n=3) target component to
be thirdly started up, the first outdoor fan (F1) as a fourth (n=4)
target component to be fourthly started up and the second outdoor
fan (F2) as a fifth (n=5) target component to be fifthly started
up. Further, in step ST3, when a startup instruction is issued to
the inverter compressor (2A), a "failure flag" is turned ON during
a given period of time T1 (for example 0.3 seconds).
[0092] Next, in step ST4, when a given period of time T2 (for
example, 0.1 seconds) passes since the startup instruction has been
issued to the inverter compressor (2A) in step ST3, the sequential
startup section (91) makes the first relay (82) of the power supply
circuit (80) to start power distribution to the inverter compressor
(2A). Then, the control proceeds to step ST5.
[0093] In step ST5, it is determined whether or not the inverter
compressor (2A) has normally started up. Specifically, as shown in
FIG. 6, if the inverter compressor (2A) continues to be driven for
a given period of time T3 (for example, 10.0 seconds) since the
start of power distribution, the inverter compressor (2A) is
determined to have normally started up and the control proceeds to
step ST7. In this case, if the given period of time T3 has passed
since the start of power distribution, the sequential startup
section (91) opens the first relay (82) to stop power distribution.
On the other hand, for example, if as shown in FIG. 7 the inverter
compressor (2A) first starts up after the start of power
distribution but the breaker (81) then trips again owing to failure
in the electric system to halt the inverter compressor (2A) before
the passage of the given period of time T3, the inverter compressor
(2A) is determined to have not normally started up and the control
proceeds to step ST6. In step ST5, not only in the case shown in
FIG. 7 but also in the case where the inverter compressor (2A) is
halted for the given period of time T3 since the start of power
distribution and in the case where it is first halted, then starts
up partway through the given period of time T3 and is halted again,
it is determined to have not normally started up. In short, in step
ST5, if the inverter compressor (2A) is halted even once during the
given period of time T3 since the start of power distribution, it
is determined to have not normally started up.
[0094] In step ST6, the failure processing section (92) excludes
the inverter compressor (2A) from the target components to be
started up by the sequential startup section (91) and leaves its
"failure flag" ON. In other words, in step ST6, the inverter
compressor (2A) is identified as a failed component. If the
inverter compressor (2A) is identified as a failed component, the
control returns to step ST1 and the breaker (81) is turned ON
again. Then, in step ST2, the number of target components is
re-identified as four (N=5-1). Specifically, in step ST2, the first
non-inverter compressor (2B), instead of the inverter compressor
(2A), is reset as a first (n=1) target component and then the
control proceeds to step ST3.
[0095] In step ST3, the sequential startup section (91)
sequentially issues startup instructions to the target components
again. Specifically, the sequential startup section (91) skips the
inverter compressor (2A) excluded from the target components and
issues a startup instruction to the first non-inverter compressor
(2B) that is the first (n=1) target component. Thereafter, the
control sequentially proceeds to the step ST4 and the subsequent
steps in the same manner as described above.
[0096] On the other hand, when the control proceeds from step ST5
to step ST7, the inverter compressor (2A) is identified as a normal
component, its "failure flag" is turned OFF and the control
proceeds to step ST8. In step ST8, it is determined whether or not
the inverter compressor (2A) is a last target component (2A, 2B, .
. . ), i.e., whether or not it is a fifth (n=N) target component.
If the inverter compressor (2A) is determined not to be a last
target component, the control returns to step ST3. If the inverter
compressor (2A) is determined to be a last target component, the
control proceeds to step ST9.
[0097] In step ST3, the sequential startup section (91) issues a
startup instruction to the first non-inverter compressor (2B) which
is a second (n=2) target component and a "failure flag" for the
first non-inverter compressor (2B) is turned ON. Thereafter, the
control proceeds to step ST4 and the subsequent steps in the same
manner as described above.
[0098] In this manner, the control of the present invention is
implemented by sequentially starting up the target components (2A,
2B, . . . ) to sequentially determine whether or not each of them
is a failed component and sequentially starting up again, if a
failed component is identified, the target components (2A, 2B, . .
. ) other than the failed component. Here, for example, suppose
that the inverter compressor (2A) is identified as a normal
component, the first non-inverter compressor (2B) is then
identified as a failed component, the second non-inverter
compressor (2C) is then identified as a normal component and the
first outdoor fan (F1) is then identified as a failed
component.
[0099] In this case, in step ST6, the first outdoor fan (F1) is
excluded from the target components to be started up by the
sequential startup section (91), its "failure flag" is left ON and
the control returns to step ST1 to turn the breaker (81) ON again.
Next, in step ST2, the number of target components is re-identified
as N=4-1=3 (i.e., the inverter compressor (2A), the second
non-inverter compressor (2C) and the second outdoor fan (F2). Then,
in step ST3, the sequential startup section (91) sequentially
issues startup instructions to the re-identified three target
components.
[0100] Specifically, first, when the sequential startup section
(91) issues a startup instruction to the inverter compressor (2A)
that is a first (n=1) target component, the control sequentially
proceeds to step ST4 and the subsequent steps, the inverter
compressor (2A) is determined in step ST8 not to be a last (n=1N)
target component and the control returns to step ST3. In step ST3,
the sequential startup section (91) skips the first non-inverter
compressor (2B) previously excluded from the target components and
issues a startup instruction to the second non-inverter compressor
(2C) that is a second (n=2) target component. Then, the control
proceeds to step ST4 and the subsequent steps, the second
non-inverter compressor (2C) is determined in step ST8 not to be a
last (n=2.noteq.N) target component and the control returns to step
ST3. Next, in step ST3, the sequential startup section (91) skips
the first outdoor fan (F1) previously excluded from the target
components and issues a startup instruction to the second outdoor
fan (F2) that is a third (n=3) target component. Then, the control
proceeds to step ST5 and then step ST7. If the second outdoor fan
(F2) is determined to be a normal component, the control proceeds
to step ST8. In step ST8, if the second outdoor fan (F2) is
determined to be a last (n=N=3) target component, the control
proceeds to step ST9 through the operation transition section
(93).
[0101] If, for the second outdoor fan (F2), the control proceeds to
step ST5 and then step ST6 and the second outdoor fan (F2) is
identified as a failed component, the control returns to step ST1,
the inverter compressor (2A) and the second non-inverter compressor
(2C) are sequentially started up as target components to be started
up by the sequential startup section (91), and, finally, the
control proceeds to step ST9.
[0102] If the second outdoor fan (F2) is identified as a last
target component and the control proceeds to step ST9, the
operation transition section (93) resumes the normal operation.
Specifically, when the breaker (81) is turned ON again, the
inverter compressor (2A), the second non-inverter compressor (2C)
and the second outdoor fan (F2), leaving out the first non-inverter
compressor (2B) and the first outdoor fan (F1) with their "failure
flags" left ON, are sequentially started up by the operation
transition section (93), thereby resuming the normal operation.
[0103] For example, in the case where the cooling and refrigeration
operation is resumed, the first non-inverter compressor (2B) is out
of action. Therefore, the cooling capacities of the chilling unit
(1C) and the freezing unit (1D) are lowered. Further, since the
first outdoor fan (F1) is out of action, the amount of heat
exchange in the outdoor heat exchanger (4) is deteriorated.
However, at least the operation can be surely resumed
(restarted).
--Effects of Embodiment--
[0104] As described so far, in this embodiment, if the breaker (81)
trips owing to failure in the electric systems of refrigeration
system components to abnormally halt the operation, the compressors
(2A, 2B, 2C) and the outdoor fans (F1, F2) previously selected as
target components are sequentially started up. If during the
sequential startup the breaker (81) trips again owing to failure in
the electric systems, the target component supplied with electric
power just before the trip is not started up anymore. Therefore,
from among the target components (2A, 2B, . . . ), a failed
component having caused failure in its electric system can be
surely identified.
[0105] Further, if all the target components (2A, 2B, . . . ) to be
sequentially started up normally start up, a transition to the
normal operation is made while the component identified as a failed
component is held halted. This avoids that the breaker (81) trips
again owing to failure in the electric system to abnormally halt
the normal operation. Therefore, though the capacity associated
with the failed component is not performed, at least the operation
can be surely resumed (restarted).
[0106] Furthermore, if a failed component is identified, the
"failure flag" for the failed component is left ON. Thus, the
failed component can be surely excluded from the target components
(2A, 2B, . . . ). Therefore, a transition to the normal operation
can be surely made.
[0107] Furthermore, three compressors (2A, 2B, 2C) and two outdoor
fans (F1, F2) are selected as the target components (2A, 2B, . . .
). Therefore, even if some of them becomes out of action owing to
failures in their electric systems, at least a normal compressor
(2A, 2B, 2C) and/or a normal outdoor fan (F1, F2) can be started
up, which ensures operation resumption.
Embodiment 2 of the Invention
[0108] A refrigeration system (1) according to Embodiment 2 is
configured to start up, at every start of the normal operation, the
target components (2A, 2B, . . . ) while determining whether or not
they are failing. In Embodiment 1, in restarting the operation
after the halt owing to electric system failure such as electric
leakage, the determination of whether the target components (2A,
2B, . . . ) are failing is made, the failed components are excluded
from the target components and the normal operation is then
resumed. In contrast, the refrigeration system (1) according to
this embodiment is configured to control startup so that, though
the determination of whether the target components (2A, 2B, . . . )
are failing is made at the start of the normal operation, the
determination is ended when the number of target components (2A,
2B, . . . ) identified as normal components reaches a necessary
number and a transition to the normal operation is then immediately
made.
[0109] Specifically, at the start of the normal operation, the
startup control on the compressors (2A, 2B, 2C) and the startup
control on the fans (F1, F2) are individually carried out
substantially at the same time. Because the startup control on the
compressors (2A, 2B, 2C) is similar to the startup control on the
fans (F1, F2), a description is given here mainly of the startup
control on the compressors (2A, 2B, 2C).
[0110] As shown in FIG. 8, first, when in step ST11 the operator or
like person turns ON the breaker (81) of the power supply circuit
(80) to distribute electric power to the refrigeration system
components, the control proceeds to step ST12. In step ST12, the
number of compressors (2A, 2B, 2C) that are target components are
identified as N=3 by the sequential startup section (91) of the
controller (90). For the startup control on the fans (F1, F2), the
number of fans (F1, F2) that are target components are identified
as N=2.
[0111] Subsequently, in step ST13, the necessary number C of
compressors (2A, 2B, 2C) for the normal operation is identified
and, then, the control proceeds to step ST14. Though the necessary
number of compressors is determined according to operating
conditions, it is assumed in this embodiment that the necessary
number is C=2. For the startup control on the fans (F1, F2), the
necessary number F of fans (F1, F2) is identified (as, for example,
F=1) in step ST13.
[0112] Next, the transitions from step ST14 to step ST16 are
processed in a similar manner to the transitions from step ST3 to
step ST5 in Embodiment 1. Specifically, in step ST14, the
sequential startup section (91) issues a startup instruction to the
inverter compressor (2A) that is a first (n=1) target compressor
and its "failure flag" is turned ON. Also in this embodiment, the
sequential startup section (91) is previously configured to
sequentially issue startup instructions in the order of the
inverter compressor (2A), the first non-inverter compressor (2B)
and the second non-inverter compressor (2C). In step ST15, the
sequential startup section (91) makes the first relay (82) of the
power supply circuit (80) to start power distribution to the
inverter compressor (2A). Then, if in step ST16 the breaker (81)
trips and the inverter compressor (2A) is determined to have not
normally started up, the control proceeds to step ST17. If in step
ST16 the inverter compressor (2A) is determined to have normally
started up, the control proceeds to step ST18.
[0113] In step ST17, like Embodiment 1, the failure processing
section (92) identifies the inverter compressor (2A) as a failed
component, excludes it from the target compressors to be started up
by the sequential startup section (91) and leaves its "failure
flag" ON. If the inverter compressor (2A) is identified as a failed
component, the control returns to step ST11 and the breaker (81) is
turned ON again. Then, in step ST12, the number of target
compressors (2A, 2B, 2C) is re-identified as two (N=3-1).
Specifically, in step ST12, the first non-inverter compressor (2B),
instead of the inverter compressor (2A), is reset as a first (n=1)
target compressor and then the control proceeds to step ST13. In
step ST13, it is confirmed that the necessary number (C=2) of
compressors (2A, 2B, 2C) is not changed. Then, the control proceeds
to step ST14.
[0114] In step ST14, the sequential startup section (91)
sequentially issues startup instructions to the target compressors
(2A, 2B, 2C) again. Specifically, the sequential startup section
(91) skips the inverter compressor (2A) excluded from the target
compressors and issues a startup instruction to the first
non-inverter compressor (2B) that is a first (n=1) target
compressor. Thereafter, the control sequentially proceeds to the
step ST15 and the subsequent steps in the same manner as described
above.
[0115] On the other hand, when the control proceeds from step ST16
to step ST18, the inverter compressor (2A) is identified as a
normal component and continues to be operated and the control
proceeds to step ST19. At the time, the "failure flag" for the
inverter compressor (2A) is turned OFF. In other words, in this
embodiment, unlike Embodiment 1, the target components identified
as normal components continue to be operated without halting power
distribution thereto.
[0116] In step ST19, it is determined whether or not the number of
compressors (2A, 2B, 2C) in operation at the current moment reaches
the necessary number (C=2) identified in step ST13. If the number
of compressors (2A, 2B, 2C) in operation is determined not to reach
the necessary number, the control returns to step ST14. On the
other hand, if the number of compressors (2A, 2B, 2C) in operation
is determined to reach the necessary number, the startup control on
the compressors (2A, 2B, 2C) ends. In the former case, since only
the inverter compressor (2A) is in operation, it is determined that
the number of compressors (2A, 2B, 2C) in operation does not reach
the necessary number, two. Therefore, the control returns to step
ST14. For the startup control on the fans (F1, F2), in step ST19,
it is determined whether or not the number of fans (F1, F2) in
operation at the current moment reaches the necessary number (for
example, F=1) identified in step ST13. If the number of fans in
operation reaches the necessary number, the startup control on the
fans (F1, F2) ends.
[0117] Subsequently, in step ST14, the sequential startup section
(91) issues a startup instruction to the first non-inverter
compressor (2B) that is a second (n=2) target compressor and,
thereafter, the control sequentially proceeds to step ST15 and the
subsequent steps in the same manner as described above. If in step
ST18 the first non-inverter compressor (2B) is identified as a
normal component and thus continues to operate, then two
compressors, i.e., the inverter compressor (2A) and the first
non-inverter compressor (2B), are in operation. Therefore, the
number of compressors (2A, 2B, 2C) in operation is determined to
reach the necessary number, two, in step ST19 and the startup
control on the compressors (2A, 2B, 2C) ends.
[0118] In contrast to the above case, if in step ST17 the first
non-inverter compressor (2B) is excluded as a failed component from
the target compressors to be started up by the sequential startup
section (91), the control returns to step ST11 and the breaker (81)
is turned ON again. Then, in step ST12, the number of target
compressors (2A, 2B, 2C) is re-identified as two (N=3-1). In other
words, in step ST12, the second non-inverter compressor (2C),
instead of the first non-inverter compressor (2B), is reset as a
second (n=2) target compressor. Then, in step ST13, the necessary
number (C=2) of compressors (2A, 2B, 2C) is reconfirmed.
Subsequently, in step ST14, the sequential startup section (91)
issues again an startup instruction to the inverter compressor (2A)
that is the first (n=1) target compressor. Then, the control
proceeds to step ST15 and the subsequent steps. While the inverter
compressor (2A) continues to normally operate, the number of
compressors (2A, 2B, 2C) in operation is determined not to reach
the necessary number, two, in step ST19. As a result, the control
returns to step ST14 and, in step ST14, the sequential startup
section (91) issues an startup instruction to the second
non-inverter compressor (2C) that is the second (n=2) target
compressor. Then, the control proceeds to step ST15 and the
subsequent steps. If in step ST18 the second non-inverter
compressor (2C) is identified as a normal component and thus
continues to operate, then the two compressors, i.e., the inverter
compressor (2A) and the second non-inverter compressor (2C), are in
operation. Therefore, the number of compressors (2A, 2B, 2C) in
operation is determined to reach the necessary number, two, in step
ST19 and the startup control on the compressors (2A, 2B, 2C)
ends.
[0119] In Embodiment 2, when both the startup control on the
compressors (2A, 2B, 2C) and the startup control on the fans (F1,
F2) end, the operation transition section (93) allows the normal
operation to be continued as it is.
[0120] As described so far, in this embodiment, like Embodiment 1,
if during the sequential startup of the compressors (2A, 2B, 2C)
and outdoor fans (F1, F2) selected as target components the breaker
(81) trips owing to failure in their electric systems, the target
component supplied with electric power just before the trip is not
started up anymore. Therefore, from among the target components
(2A, 2B, . . . ), a failed component having caused failure in its
electric system can be surely identified.
[0121] Further, in this embodiment, the determination of whether
the target components are failing is made not for all the
compressors (2A, 2B, 2C) and fans (F1, F2) as done in Embodiment 1
but is ended at the time when the number of normal components is
determined to reach the necessary number. Thus, only refrigeration
system components of the number according to the necessary
refrigeration capacity can be surely started up. This eliminates
the need to determine whether unnecessary components for operation
are failing, which shortens the time taken to start the normal
operation. The rest of the configuration, the other behaviors and
effects are the same as in Embodiment 1.
Other Embodiments
[0122] The above embodiments of the present invention may have the
following configurations.
[0123] For example, though in the above embodiments the compressors
(2A, 2B, 2C) and the outdoor fans (F1, F2) are selected as target
components to be started up by the sequential startup section (91),
the booster compressor (53) and/or the four-way selector valves
(3A, 3B, 3C) may be additionally selected or either of the
compressors (2A, 2B, 2C) or the outdoor fans (F1, F2) may be
selected.
[0124] Alternatively, a plurality of utilization fans including the
indoor fan (43) and the chilling fan (47) may be provided and
selected as target components to be started up by the sequential
startup section (91).
[0125] Though in the above embodiments three compressors (2A, 2B,
2C) are provided in the outdoor unit (1A), it goes without saying
that any one of them may be dispensed with.
[0126] Though in the above embodiments each unit (1A, 1B, 1C) is
singular, it goes without saying that each unit (1A, 1B, 1C) may
comprise a plurality of units.
[0127] The above embodiments are merely preferred embodiments in
nature and are not intended to limit the scope, applications and
use of the invention.
INDUSTRIAL APPLICABILITY
[0128] As seen from the above, the present invention is useful as a
refrigeration system with various kinds of motor-operated
refrigeration system components.
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