JPH06347116A - Freezer device - Google Patents

Abstract

PURPOSE:To make it hard to accumulate refrigerant in an inter-unit pipe or a heat exchanger when a heating operation is started. CONSTITUTION:A degree of opening of each of indoor electrical expansion valves (pressure reducing valves) 351 and 352 of indoor units 31 and 32 is made larger than of normal operation when a heating operation is started. Compressors A and B of outdoor units 11 and 12 are operated without having any relation with a load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus provided with a heat source side unit having at least a compressor and a use side unit having at least a pressure reducing valve, and connecting these units with unit piping.

[0002]

2. Description of the Related Art Generally, a refrigeration system (air conditioner) in which a heat source side unit and a use side unit are connected by unit piping
Is a split type air conditioner for home use (room air conditioner)
And air conditioners for buildings (package air conditioners) as proposed in Japanese Patent Application No. 4-78874.

[0003]

In a room air conditioner, when there is one use side unit, when the capacity of this use side unit (use side heat exchanger) is small, or when the length of the piping between the units is short. There are many. For this reason, even if refrigerant accumulates in the heat exchanger on the utilization side or the inter-unit pipe (sleeping) at the start of the heating operation, these refrigerants gradually flow out after the start of operation, so that a shortage of the refrigerant rarely occurs.

However, in a packaged air conditioner, a plurality of use side (indoor) units and heat source side (outdoor) units are provided, and the operation control of these units is individually performed according to the load. Further, when the heat source side unit is installed on the rooftop of a high-rise building or the like, the inter-unit piping connecting the indoor use side unit and this heat source side unit is inevitably long. For these reasons, the refrigerant is likely to accumulate in the use side unit during the heating operation stop and the inter-unit piping connected to the use side unit during the heating operation stop, and the accumulated refrigerant does not flow out even during the operation. Therefore, the refrigerant circulation amount as the device is reduced,
There was a risk that the temperature of the refrigerant would rise abnormally and prevent normal operation.

An object of the present invention is to prevent the accumulation of refrigerant at the start of operation.

[0006]

In order to achieve this object, the present invention makes the opening degree of the pressure reducing valve of the utilization side unit larger than that at the normal time at the start of the heating operation, and also improves the compressor of the heat source side unit. It is designed to operate regardless of the load.

[0007]

[Operation] At the start of the heating operation, the operation of the pressure reducing valve and the compressor whose opening is set to a large value causes the refrigerant accumulated in the use side unit and the unit-to-unit piping to be promptly returned to the heat source side unit, so that a refrigerant shortage is less likely to occur. .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 ₁ and 1 ₂ are first and _second heat source side units (hereinafter referred to as “outdoor units”), 3 ₁ and
3 ₂ is a user side unit (hereinafter referred to as “indoor unit”)
Is.

The first outdoor unit 1 ₁ includes an accumulator 10 ₁ , a constant capacity compressor A, and a variable capacity compressor B whose capacity can be variably controlled according to the air conditioning load in the room.
Oil separator 12 ₁ , four-way valve 13 ₁ and outdoor heat exchanger 14 ₁
When configured by the outdoor electric expansion valve (the outdoor side decompression valve) 15 _1. Further, the second outdoor unit 1 ₂ includes an accumulator 10 ₂ , a constant capacity compressor C, and an oil separator 12 _2.
, A four-way valve 13 ₂ , an outdoor heat exchanger 14 _2, and an outdoor electric expansion valve (outdoor pressure reducing valve) 15 ₂ .

These outdoor electric expansion valves 15₁, 15₂Open
In each case, each outdoor heat exchanger 14₁, 14₂Sen
SA 16₁, 16₂Temperature detected by the outdoor heat exchanger
14 ₁, 14₂Controller 17 based on the temperature of₁, 17₂Through
Will be decided. Indoor unit 3₁, 3₂Indoor heat exchange
Bowl 34₁, 34₂And indoor electric expansion valve (pressure reduction inside the room
Valve) 35₁, 35₂Composed of and. This indoor unit 3
₁, 3₂Between the units consisting of gas pipe 5 and liquid pipe 7.
Piping extends out and these inter-unit
Outer unit 1₁, 1₂Are connected in parallel. These indoor power
Dynamic expansion valve 35₁, 35₂The opening of each is in each room
Heat exchanger 34₁, 34₂Sensor 36₁, 36₂Detected by
Temperature, that is, indoor heat exchanger 34₁, 34₂Based on the temperature of
Controller 37₁, 37₂It is normally determined via.

Oil separator 12 of the _first outdoor unit 1 _1.
1 is for separating the lubricating oil in the refrigerant discharged from the compressors A and B, and the lubricating oil separated here is the return pipe 2
It is returned to the compressors A and B through 1 ₁ . The return pipe 21 ₁ is provided with an on-off valve 23 ₁ . Moreover, the oil separator 12 ₂ of the outdoor unit 1 ₂ is intended to separate the lubricating oil in the refrigerant discharged from the compressor C, where separated lubricating oil to the compressor C through return pipe 21 ₂ Will be returned. The return pipe 21 ₂ is provided with an on-off valve 23 ₂ .

The return pipes 21 ₁ and 21 _{2 of} the first and _second outdoor units 1 ₁ and 1 ₂ are connected by a balance pipe 51. The balance pipe 51 transfers the lubricating oil from a compressor with a large amount of lubricating oil to a compressor with a small amount of lubricating oil when an unbalance of the amount of lubricating oil occurs between the compressors of the first and _second outdoor units 1 ₁ and 1 _2. It is a conduit for leading. 60 is a control device,
Sensor 63 provided in the indoor unit 3 _1, 3 _{2 1,} 63 ₂
From the indoor unit 3 ₁ at the start of the heating operation, the indoor air conditioning load is obtained by inputting a signal from the indoor air conditioning load, and the operation of the compressors A, B, and C is controlled as shown in FIG. , 3 ₂ of the indoor electric expansion valves 35 ₁ and 35 ₂ are set to fully open (predetermined opening) and the compressors A, B and C are operated at maximum capacity regardless of the air conditioning load. And a controller 62 of. The solid line in FIG. 1 indicates the flow of the refrigerant when the heating operation is started, and the broken line indicates the flow of the refrigerant when the heating load is 6 horsepower. The four-way valves 13 ₁ and 13 ₂ are set to the broken line state during cooling and to the solid line state during heating.

The compressors A, B and C are, as shown in FIG.
The compressor A is a constant capacity compressor of 4 horsepower (ps), the compressor B is a variable capacity compressor of 6 ps capable of variably controlling the capacity (rotation speed) according to the air conditioning load, and the compressor C is 10
It is a constant capacity compressor of ps. In the multi-type air conditioner of such combination, for example, during operation, when the air conditioning load decreases below the maximum output of the outdoor unit, control is performed to stop the operation of some outdoor units.

[0014] That is, in order to control the output in the range of 1~6ps is driving a first outdoor unit 1 ₁ of the variable capacity compressor B, a dotted arrow in FIG. 1 the coolant is controlled within the variable range Flush as shown in. Further, to control the output in the range of 7~10ps is to first outdoor unit 1 ₁ capacity constant compressor A to (4 ps) to leave driving the remaining 3~6ps
Is controlled by operating the variable capacity compressor B. Further, in order to control the output in the range of 11~16ps the second outdoor unit 1 ₂ capacity constant compressor C of (10 ps) and the leave driving, the remaining 1~6ps first outdoor unit 1
_{It is} controlled by the operation of the variable capacity compressor B of ₁ .

Furthermore, to control the output in the range of 17~20ps the second outdoor unit 1 ₂ capacity constant compressor C
(10 ps), and the first outdoor unit 1 ₁ capacity constant compressor A (4 ps) in the leave drove the remaining 3
6 ps is controlled by operating the variable capacity compressor B of the first outdoor unit 1 ₁ . According to this, the output in the entire range up to the rated load can be smoothly controlled.

By the way, when the above heating operation is started, first, the following specific control of the present invention is performed. As for the control, referring to FIG. 1 and FIG. 3, when the heating operation is first started (S ₁ ), first of all, the indoor electric expansion valves of all the indoors are instructed by the signals of the controller 60 and the controllers 62, 37 ₁ , 37 _2. The openings of 35 ₁ and 35 ₂ are set to full opening (predetermined opening) (first control means: S ₂ ). Then, all of the outdoor units ₁ 1, 1 ₂ of the compressor A, B, thereby operating the C (S _3). Here, in the compressors B and C, the number of rotations is set so that the capacity is maximized regardless of the heating load. Then, after such control is continued for at least 1 minute (S ₄ ), the temperatures of the indoor heat exchangers 34 ₁ and 34 ₂ are detected next, and the above-described control is performed until all the temperatures become equal to or higher than a predetermined value. It is carried out (S ₅ ~S _6). After that, the control shifts to the control based on the air conditioning load (see FIG. 2). Specifically, if the air conditioning load is 6 horsepower, the operation of the outdoor unit 1 ₂ is stopped and only the outdoor unit 1 ₁ is operated (the state of the broken line in FIG. 1).

As described above, at the start of the heating operation, the opening degree of the indoor electric expansion valves 35 ₁ and 35 ₂ is fully opened and all the compressors A, B and C are operated at the maximum capacity regardless of the air conditioning load. Therefore, as shown by the solid line in FIG. 1, all the refrigerant discharged from the compressors A, B, and C in the gas pipe 5 passes through the indoor units 3 ₁ and 3 ₂ and the liquid pipe 7 to the outdoor unit. It is introduced into 1 ₁ and 1 ₂ to prevent refrigerant pooling in these. The gas pipes 5 and the liquid pipes 7 are usually covered with a heat insulating material to prevent them from being affected by the outside air temperature, but the refrigerant easily accumulates in the gas pipes 5 especially in winter when the outside air temperature is low. However, due to the control described above, this refrigerant pool hardly occurs.

In addition, since the temperature rise of the gas pipe 5 itself is accelerated by such control as compared with the case where the gas pipe 5 is operated based on the air conditioning load, the rising characteristic of the heating operation is significantly improved. Also, in this control,
For at least 1 minute, the temperatures of the indoor heat exchangers 34 ₁ and 34 ₂ are not detected, and the indoor electric expansion valves 35 ₁ and 35 ₂ are fully opened and all the compressors A, B, and C are operated. The reason for doing so is as follows.

[0019] That is, if comparatively indoor temperature is higher at the beginning the heating operation, though soon indoor heat exchanger 34 _1, 34 ₂ of the temperature rises to a predetermined value, the indoor heat exchanger 34 ₁ at this time, 34 _This is because it is conceivable that not all of the refrigerant accumulated in ₂ and the gas pipe 5 has been collected in the outdoor units 1 ₁ and 1 ₂ . The above explanation is for the outdoor unit 1 ₁ ,
1 ₂ and the indoor units 3 ₁ and 3 ₂ were both carried out in an air conditioner provided with a plurality of units, but the present invention is not limited to this, and any one unit may be one. .

Although the above description has been made only when the heating operation is started, the most refrigerant at this time is the gas pipe 5.
It is because it is easy to accumulate in etc.

[0021]

As described above, according to the present invention, when the heating operation is started, the opening degree of the pressure reducing valve of the utilization side unit is made larger than that at the normal time and the capacity of the compressor of the heat source side unit is increased irrespective of the load. Therefore, the refrigerant accumulated in the use side unit or the inter-unit pipe is promptly returned to the heat source side unit, and the shortage of the refrigerant hardly occurs. As a result, it is possible to prevent the temperature of the discharged refrigerant from rising abnormally or becoming inoperable.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigerating apparatus of the present invention.

FIG. 2 is an explanatory diagram showing an operating state of the compressor shown in FIG.

FIG. 3 is a flowchart of the control device and controller shown in FIG.

[Explanation of symbols]

1 ₁ , 1 ₂ Outdoor unit (heat source side unit) 3 ₁ , 3 ₂ Indoor unit (use side unit) 35 ₁ , 35 ₂ Indoor electric expansion valve (pressure reducing valve) 37 ₁ , 37 ₂ , 62 Controller B Capacity variable Type compressor S ₂ First control means S ₃ Second control means

Claims (1)

[Claims] 1. A refrigerating apparatus comprising a heat source side unit having at least a compressor and a utilization side unit having at least a pressure reducing valve, and connecting both of these units with unit piping to open the pressure reducing valve at the start of heating operation. And a second control means for operating the compressor independently of the refrigeration load in cooperation with the first control means. Refrigerating device.