JP2810422B2 - Refrigeration equipment - Google Patents

Description

The present invention relates to a refrigerating apparatus suitable for a heat pump type air conditioner for cooling and heating multiple rooms.

(B) Conventional technology A refrigeration system in which a variable-speed compressor and a constant-capacity compressor are connected in parallel, and these compressors, a condenser, a decompressor, and an evaporator are sequentially connected to form a refrigerant circuit. Equipment is fair 1
No. -9280.

(C) Problems to be Solved by the Invention In the device presented in the above publication, the variable speed compressor and the constant capacity compressor have the same capacity. For example, the total capacity of both compressors is 10 horsepower and the speed is variable. 35% capacity control range of compressor
(1.5 hp) to 100% (5 hp), the total capacity control range of both compressors will be 1.5 hp to 10 hp, and if the capacity to meet the air conditioning load is less than 1.5 hp, variable speed compression There was a problem that the frequency of starting and stopping the machine increased, and the fluctuation in room temperature increased.

It is an object of the present invention to provide a refrigeration apparatus that solves the above problem and prevents the total output from both compressors from changing rapidly.

(D) Means for Solving the Problems According to the present invention, a variable speed compressor and a constant capacity compressor are connected in parallel, and both compressors, a condenser, a decompressor, and an evaporator are sequentially connected. In the refrigeration system in which the refrigerant circuit is formed, the maximum capacity of the variable speed compressor is set to be smaller than the rated capacity of the constant capacity compressor, while the refrigerant discharge pipe and the refrigerant suction pipe of both compressors are connected. A straddle bypass path is provided, and the bypass path is provided with a bypass valve that opens and closes when the operation capacity of the variable speed compressor is minimized and the constant capacity compressor starts and stops.

Further, the present invention provides a refrigeration system in which a variable rotation type compressor and a pole number conversion type compressor are connected in parallel, and the compressor, a condenser, a decompressor, and an evaporator are sequentially connected to form a refrigerant circuit. In the device, while setting the maximum capacity of the variable speed variable type compressor smaller than the maximum capacity of the pole number conversion type compressor, a bypass path is provided across the refrigerant discharge pipe and the refrigerant suction pipe of both compressors, The bypass path is characterized in that a bypass valve is provided which opens and closes when the operation capacity of the variable speed compressor is minimized and the pole number conversion type compressor starts and stops and the pole number is changed.

In addition, the present invention connects a variable-speed compressor and a capacity-saving compressor that returns a part of the refrigerant being compressed to the suction side in parallel, and these compressor, condenser, decompressor, and evaporator are connected. Are sequentially connected to form a refrigerant circuit, the maximum capacity of the variable-speed compressor is set smaller than the maximum capacity of the capacity-saving compressor, while the refrigerant discharge pipe and the refrigerant suction pipe of both compressors are set. A bypass path is provided across the pipe, and a bypass valve that opens and closes when the operation capacity of the variable speed compressor is minimized and the capacity saving type compressor starts and stops is provided in the bypass path. I do.

(E) Operation The maximum capacity of the variable speed compressor is, for example, horsepower, the rated capacity of the constant capacity compressor is 6 horsepower, or the maximum capacity of the pole conversion type compressor or the capacity saving type compressor is 6 horsepower. Assuming that the capacity control range of the variable speed compressor is 30% (1.2 hp) to 100% (4 hp), the total output control range of both compressors is 1.2 hp to 10 hp, and the lower limit of the output control range , The frequency at which the variable speed compressor starts and stops is reduced, and the room temperature fluctuation is reduced.

At the same time, the operating capacity of the variable speed compressor was minimized, and the constant capacity compressor, the pole number conversion type compressor, and the capacity saving type compressor started or stopped, or the pole number conversion type compressor changed the pole number. At this time, since the bypass valve is opened and closed, the total output from the compressor does not fluctuate rapidly.

(F) Embodiment The first embodiment of the present invention will be described with reference to FIGS. 1 and 2. (1) The operating frequency is changed by the inverter device (2), the minimum capacity is 1.2 horsepower and the maximum capacity is 4 hp variable speed compressor (3), constant capacity compressor with rated capacity of 6 hp (4), and heat source side heat exchanger (5)
And a heat-source side unit having a gas-liquid separator (6), (7
a) (7b) (7c) are heat exchangers on the use side (8a) (8b) (8c)
And a 1.5-hp, 3.5-hp, 5-hp power unit with a heat source-side heat exchanger (5) and both compressors (3)
The refrigerant discharge pipe (9) and the refrigerant suction pipe (10) of (4) are branched and connected via switching valves (11a) (11b), while the heat source side unit (1) and the utilization side units (7a) (7b ) And (7c), a high-pressure gas pipe (13) branched and connected to the refrigerant discharge pipe (9), and a low-pressure gas pipe (14) branched and connected to the refrigerant suction pipe (10). ) And a liquid pipe (15) connected to the heat source side heat exchanger (5), and each use side heat exchanger (8a) (8b) (8c) is connected to a high pressure gas pipe (13) and a low pressure gas pipe (13). Switching valves (16a) (17a) and (16a) are connected to the gas pipe (14), respectively.
b) Branch connection via (17b), (16c) and (17c) and a refrigerant pressure reducer (18a) such as an electric expansion valve in the liquid pipe (15)
(18b) are connected via (18c).

(19) is a check valve provided in the discharge branch pipe (9a) of the constant capacity compressor (4), and (20) and (21) are straddling the refrigerant discharge pipe (9) and the refrigerant suction pipe (10). The bypass passage is provided with a bypass valve that opens and closes when the operation capacity of the variable speed compressor (3) is minimized and the constant capacity compressor (4) starts and stops. 22) and (23).
The two bypass valves are opened and closed by a controller (24).

Next, the driving operation will be described. When cooling all the rooms at the same time, one switching valve (11a) of the heat source side heat exchanger (5) is opened and the other switching valve (11b) is closed, and the use side heat exchangers (7a) (7b) (7c) One switching valve (16a) (16b)
(16c) is closed and the other switching valve (17a) (17b) (1
By opening 7c), the refrigerant discharged from the compressors (3) and (4) flows sequentially through the discharge pipe (9), the switching valve (11a), and the heat source side heat exchanger (5), where it is condensed and liquefied. Thereafter, the refrigerant is distributed to the refrigerant decompressors (18a), (18b), and (18c) of each of the use-side units (7a), (7b), and (7c) via the liquid pipe (15), where the pressure is reduced. After that, each use side heat exchanger (8a) (8b) (8
After evaporating in c), the switching valves (17a), (17b), (17
c), is sucked into the compressors (3) and (4) through the low-pressure gas pipe (14), the suction pipe (10), and the gas-liquid separator (6) in this order. Thus, each use side heat exchanger acting as an evaporator (8a)
(8b) In (8c), all rooms are cooled simultaneously.

Conversely, when heating all the rooms at the same time, one switching valve (11a) of the heat source side heat exchanger (5) is closed and the other switching valve (11b) is opened, and the use side heat exchanger (8a) ( 8b) (8
By opening one of the switching valves (16a) (16b) (16c) and closing the other switching valve (17a) (17b) (17c), the refrigerant discharged from the compressors (3) and (4) Through the discharge pipe (9) and the high-pressure gas pipe (13) in that order, the switching valve (16a) (1
6b) (16c), distributed to the use side heat exchangers (8a) (8b) (8c) where they are condensed and liquefied respectively, and then decompressed by each refrigerant decompressor (18a) (18b) (18c). After being merged in the liquid pipe (15), and then evaporated and vaporized in the heat source side exchanger (5),
The gas is sucked into the compressors (3) and (4) through the switching valve (11b), the suction pipe (10), and the gas-liquid separator (6) sequentially. Thus, each use side heat exchanger (8a) (8b) (8
In c) all rooms are heated simultaneously.

The operation of the variable speed compressor (3) and the constant capacity compressor (4) and the opening and closing operations of the bypass valves (22) and (23) in the simultaneous cooling operation and the simultaneous heating operation will be described with reference to FIG. Then, first, the variable speed compressor (3) starts operation (point A) with a minimum capacity of 1.2 horsepower by an output signal from the inverter device (2) and reaches a capacity of 3.6 horsepower (B).
Point) and the minimum capacity is reduced to 1.2 hp and the controller (2
With the signal from 4), the constant capacity compressor (4) is started to operate at the rated capacity of 6 hp and the bypass valve (22) with the bypass capacity of 30% and the bypass valve (23) with the bypass capacity of 20% open,
The operating capacity of the constant capacity compressor (4) after the start of operation, that is, the total capacity of the operating capacity of the constant capacity compressor (4), 6 hp and the variable speed compressor (3), 1.2 hp, 7.2 The operating capacity of the constant capacity compressor (4) before starting operation, ie, the operating capacity of the variable speed compressor (3) minus 3.6 horsepower is equivalent to 3.6 horsepower (50% of the total capacity 7.2 horsepower) from horsepower. A small amount of the discharged gas refrigerant is bypassed from the discharge pipe (9) to the suction pipe (10) through the bypass valves (22) and (23) having a total bypass capacity of 50%. Therefore, the variable speed compressor (3)
When the constant capacity compressor (4) is started to operate at the same time as the 3.6 hp reduced to 1.2 hp, the compressors (3) and (4) are sent to the high pressure gas pipe (13) via the discharge pipe (9). The total force rises linearly and there is no fear that the room temperature will fluctuate rapidly. Thereafter, when the operating capacity of the variable speed compressor (3) increases and reaches 4 hp (point C), the bypass valve (23) having a bypass capacity of 20% is closed, and then the variable speed compressor (3) is closed. )
Driving capacity reaches 2.2 hp and decreases to 1.2 hp (D
Point) and the signal from the controller (24) opens the bypass valve (23) with a bypass capacity of 20% and simultaneously closes the bypass valve (22) with a bypass capacity of 30%, then the variable speed compressor (3) Driving capacity reaches 3 hp and drops to 1.2 hp (point E)
And the bypass valve (23) with a bypass capacity of 20% is closed.
Both compressors until the operating capacity of the variable speed compressor (3) reaches 4 hp and the total capacity of the constant capacity compressor (4) and the operating capacity of 6 hp reaches a maximum of 10 hp (point F). (3) The total force sent from (4) to the high-pressure gas pipe (13) via the discharge pipe (9) rises linearly, and the room temperature does not fluctuate rapidly.

In this way, during simultaneous cooling operation and simultaneous heating operation, the use side units (7a) (7b) (7c) have the maximum operating capacity.
The cooling and heating operation is performed at 10 hp, but when the use side unit (7a) having a capacity of 1.5 hp and the use side unit (7c) having a capacity of 5 hp are turned off, the variable speed compressor ( 3) and the bypass valves (22) and (23) rotate inversely to the above operation (shift from point E to point C), the total output decreases linearly, and the total output decreases to 3.6 horsepower and rotates. When the variable capacity compressor (3) has a minimum capacity of 1.2 horsepower (point B), the constant capacity compressor (4) stops operating by a signal from the controller (24), and at the same time the bypass valve (22).
(23) is closed and the operating capacity of the variable speed compressor (3) is
The output delivered to the high-pressure gas pipe (13) via the discharge pipe (9) to rise to 3.6 horsepower also becomes 3.6 horsepower. As described above, since the output decreases linearly, the room temperature does not fluctuate rapidly.

And a user unit (7b) with a 3.5 horsepower capability
Reduced to less than 1.5 hp due to a decrease in the indoor heating and cooling load,
Accordingly, the variable speed compressor (3) has an operating capacity of 1.
Since the engine is continuously operated until the horsepower drops to 5 hp and further to the lower limit of 1.2 hp, the frequency of starting and stopping of the variable speed compressor (3) is reduced, and the fluctuation in room temperature is suppressed.

In the case where two arbitrary rooms are cooled at the same time and one room is heated at the same time, one switching valve (11a) of the heat source side heat exchanger (5) is used.
Is opened and the other switching valve (11b) is closed, and one of the switching valves (16) of the user-side units (7a) (7c) to be cooled.
a) (16b) is closed and the other switching valve (17a) (17c)
When one of the switching valves (16b) of the user-side unit (7b) for heating and opening is opened and the other switching valve (17b) is closed, a part of the refrigerant discharged from the compressors (3) and (4) is opened. Flows through the discharge pipe (9) and the switching valve (11a) sequentially to the heat source side heat exchanger (5), and the remaining refrigerant is heated via the high pressure gas pipe (13). 16b),
It flows to the use side heat exchanger (8b) and is condensed and liquefied by the use side heat exchanger (7b) and the heat source side heat exchanger (5). The refrigerant condensed and liquefied in the heat exchangers (8b) and (5) passes through the liquid pipe (15) and is decompressed by the refrigerant depressurizers (18a) and (18c) of the utilization units (7a) and (7c). , Is evaporated and vaporized in the respective use-side heat exchangers (8a) (8c), and then merged in the low-pressure gas pipe (14) via the switching valves (17a) (17c).
It is sucked into the compressors (3) and (4) through the suction pipe (10) and the gas-liquid separator (6) in order. Thus, one room is heated by the use side heat exchanger (8b) acting as a condenser, and two rooms are cooled by the other use side heat exchangers (8a) (8c) acting as an evaporator.

During such simultaneous cooling and heating operation, the operating capacity of the heating use side unit (7b) is 3.5 hp and the operating capacity of the cooling use side units (7a) (7c) is 6.5 hp. The variable speed compressor (3) is operated at 2.1 horsepower, the constant capacity compressor (4) is operated at 6 horsepower and the bypass valve has a 30% bypass capacity (point G) as shown in the figure (point G). When the bypass valve (23) with the bypass capacity of 20% is opened and the bypass valve (23) with the bypass capacity of 20% is opened, the 80% capacity (about 6.5 horsepower) of the total capacity of 8.1 hp of both compressors (3) and (4) is output.

FIGS. 3 and 4 show a second embodiment of the present invention, in which the operating frequency is changed by the inverter device (2) and the minimum capacity is 1.2 hp and the maximum capacity is 4 hp. The number of poles is switched between 2 poles and 4 poles by the machine (3) and the pole number conversion device (25), and the minimum capacity is 3 horsepower (4 pole operation) and the maximum capacity is 6 horsepower (2 pole operation) The parallel connection of the pole number conversion type compressor (26) and the bypass passage (2) extending across the refrigerant discharge pipe (9) and the refrigerant suction pipe (10) are performed.
7) The signal of the controller (24) when the operating speed of the variable speed compressor (3) becomes the minimum (1.2 hp) and the pole conversion type compressor (26) starts and stops and the pole number is changed The fifth embodiment is different from the first embodiment in that a bypass valve (28) having a bypass capacity of 5%, which is opened and closed by a switch, is connected to the first embodiment. Similarly, the same reference numerals are given and the description is omitted. The control operation based on the above difference will be described with reference to FIG. 4. The pole conversion type compressor (26) starts operation with four poles (3 hp) at the time of output increase, or the pole number conversion type compressor at the time of output decrease. Machine (26) is 4
When the operation is stopped at the poles (3 hp) (point H), and when the output rises, the pole number conversion type compressor (26) changes from 4 poles (3 hp) to 2
When the pole number conversion type compressor (26) switches from 2 poles (6 hp) to 4 poles (3 hp) (point I) when the output is switched to pole (6 hp) or the output drops, the bypass valve (28 ) Is opened and closed, the output rises or falls linearly, and the room temperature does not fluctuate rapidly.

FIGS. 5 and 6 show a third embodiment of the present invention, in which the operating frequency is changed by an inverter device (2) and the minimum capacity is 1.2 horsepower and the maximum capacity is 4 horsepower. (3) A capacity saving compressor (31) with a minimum capacity of 4.2 hp and a maximum capacity of 6 hp with the capacity saving device (29) opening and closing the 30% capacity save valve (30) in parallel And a refrigerant discharge pipe (9) and a refrigerant suction pipe (1
Control when the operating capacity of the variable speed compressor (3) becomes minimum (1.2 horsepower) and the capacity saving type compressor (31) starts and stops on the bypass path (27) straddling 0) Is different from the first embodiment in that a bypass valve (32) having a bypass capacity of 25%, which is opened / closed by a signal from a heater (24), is connected. The same reference numerals are given to the same components as in the first embodiment, and the description will be omitted. The control operation based on the above difference will be described with reference to FIG. 6.
When the operation is started at horsepower or the capacity saving type compressor (31) stops operating at 4.2 horsepower when the output drops (J point), the bypass valve (32) is opened and closed, so that the output is linear. It rises or falls and the room temperature does not fluctuate rapidly.

FIGS. 7 and 8 show a fourth embodiment of the present invention, in which the operating frequency is changed by the inverter device (2), and the variable speed compression type has a minimum capacity of 1.2 horsepower and a maximum capacity of 4 horsepower. The number of poles is switched between 2 poles and 4 poles by the machine (3) and the pole number conversion device (25), and the minimum capacity is 3 horsepower (4 pole operation) and the maximum capacity is 6 horsepower (2 pole operation) A pole number conversion type compressor (26) and a constant capacity type compressor (33) having a rated capacity of 10 horsepower are connected in parallel, and a straddle between the refrigerant discharge pipe (9) and the refrigerant suction pipe (10) is provided. Operating speed of the variable speed compressor (3) is minimum (1.2 hp) in the bypass path (27)
12% bypass capacity that is opened and closed by the signal of the controller (24) when the pole number conversion type compressor (26) starts and stops and the number of poles changes, or when the constant capacity type compressor (33) starts and stops Is different from the first embodiment in that the bypass valve (34) of
The operating operations of the simultaneous cooling operation, the simultaneous heating operation, and the simultaneous cooling / heating operation are the same as those in the first embodiment, and are denoted by the same reference numerals, and description thereof is omitted. The control operation based on the above difference will be described with reference to FIG. 8. When the output increases, the pole number conversion type compressor (26)
Starts operation with 4 poles (3 hp), or when the pole number conversion type compressor (26) stops operation with 4 poles (3 hp) when the output drops (point K) and when the output rises Conversion type compressor (2
6) switches from 4 poles (3 hp) to 2 poles (6 hp)
Or, when the pole number conversion type compressor (26) switches from 2 poles (6 horsepower) to 4 poles (3 horsepower) at the time of output decrease (point L), and at the time of output increase, the constant capacity compressor (33) Start driving,
Alternatively, when the operation is stopped (point M) when the output is lowered, the bypass valve (34) is opened and closed, so that the output rises or falls linearly, and the room temperature does not fluctuate rapidly.

In each of the above embodiments, the unit-to-unit pipe (12) is composed of three cooling / heating pipes: a high-pressure gas pipe (13), a low-pressure gas pressure (14), and a liquid pipe (15). With a simple circuit configuration using a side heat exchanger, it is possible to freely select the cooling / heating operation as well as the simultaneous cooling operation and simultaneous heating operation of a plurality of use side units with any user side unit. At the same time, the simultaneous use of air conditioning and heating allows the use-side heat exchanger used as a condenser and the use-side heat exchange acting as an evaporator to be connected in series, thus enabling efficient operation by heat recovery. The invention is not limited to only such a cooling circuit.

(G) Effect of the Invention According to the present invention, the maximum capacity of the variable speed compressor is determined by the rated capacity of the constant capacity compressor, the maximum capacity of the pole number conversion type compressor, and the maximum capacity of the capacity saving type compressor. Since the lower limit value of the total output is set lower, the output control range is widened and the frequency of the variable speed compressor starts and stops less. Since the compressors have different capacities, the oil balance between the compressors can be improved.

At the same time, the operating capacity of the variable speed compressor was minimized, and the constant capacity compressor, the pole number conversion type compressor, and the capacity saving type compressor started or stopped, or the pole number conversion type compressor changed the pole number. At this time, since the bypass valve is opened and closed, proportional control from a small output to a large output can be performed with a small-capacity inverter device, and a rapid change in the output can be prevented.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigeration apparatus showing a first embodiment of the present invention, FIG. 2 is an explanatory diagram showing a control operation of a compressor and a bypass valve in the embodiment, and FIG. 3 is a second embodiment of the present invention. Fig. 4 is a refrigerant circuit diagram of a refrigeration apparatus showing an embodiment, Fig. 4 is an explanatory diagram showing control operations of a compressor and a bypass valve in the embodiment, and Fig. 5 is a refrigerant circuit of a refrigeration apparatus showing a third embodiment of the present invention. FIG. 6, FIG. 6 is an explanatory view showing a control operation of the compressor and the bypass valve in the embodiment, FIG. 7 is a refrigerant circuit diagram of a refrigerating apparatus showing a fourth embodiment of the present invention, and FIG. It is explanatory drawing which shows the control operation of a compressor and a bypass valve in FIG. (3) ... variable speed compressor, (4) (33) ... constant capacity compressor, (9) ... refrigerant discharge pipe, (10) ... refrigerant suction pipe, (20) (21) (27) ...... Bypass road, (22) (2
3) (28) (32) (34) ... bypass valve, (26) ... pole number conversion type compressor, (31) ... capacity saving type compressor.

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasuhisa Izaki 2--18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (56) References JP-A-63-49667 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) F25B 1/00 361

Claims (3)

(57) [Claims] 1. A refrigeration system in which a variable speed compressor and a constant capacity compressor are connected in parallel, and the compressor, a condenser, a decompressor, and an evaporator are sequentially connected to form a refrigerant circuit. In the above, while the maximum capacity of the variable speed compressor is set smaller than the rated capacity of the constant capacity compressor, a bypass path is provided across the refrigerant discharge pipe and the refrigerant suction pipe of both compressors, A refrigeration system characterized in that a bypass valve is provided on the road to open and close when the operation capacity of the variable speed compressor is minimized and the constant capacity compressor is started and stopped. 2. A refrigeration system in which a variable speed compressor and a pole number conversion compressor are connected in parallel, and the two compressors, the condenser, the decompressor, and the evaporator are sequentially connected to form a refrigerant circuit. In the device, while setting the maximum capacity of the variable speed variable type compressor smaller than the maximum capacity of the pole number conversion type compressor, a bypass path is provided across the refrigerant discharge pipe and the refrigerant suction pipe of both compressors,
A refrigeration system comprising a bypass valve provided in the bypass passage to open and close when the operation number of the variable speed compressor is minimized and the pole number conversion type compressor starts and stops and the number of poles is changed. 3. A variable speed compressor and a capacity saving compressor capable of returning a part of refrigerant during compression to a suction side are connected in parallel, and these compressor, condenser, decompressor and evaporator are connected. In a refrigeration system in which refrigerant circuits are sequentially connected to form a refrigerant circuit, the maximum capacity of the variable-speed compressor is set smaller than the maximum capacity of the capacity-saving compressor, while the refrigerant discharge pipe and the refrigerant suction pipe of both compressors are set. And a bypass valve that opens and closes when the operating capacity of the variable speed compressor is minimized and the capacity saving type compressor starts and stops. Refrigeration equipment.