JPH04278150A - Cooling and heating device - Google Patents

Abstract

PURPOSE:To restrict an amount of discharged oil within a compressor to a minimum value during heating operation by a method wherein the first cylinder disposed below the compressor is connected to an outdoor heat exchanger and the second cylinder disposed above the compressor is connected to a refrigerant heating side. CONSTITUTION:Refrigerant at a suction side of the second cylinder 35 at a refrigerant heating side has a low specific volume due to the fact that its pressure is higher as compared with that of refrigerant in the first cylinder 33. In the case of the cylinders having the same capacity to each other, the second cylinder 35 had remarkably higher flow rate than that of the first cylinder 33 at the same member of rotation. Although lubricant oil within the compressor 25 is apt to be easily accumulated at the lower first cylinder 33 due to its own weight, the first cylinder 33 has a quite low flow rate of refrigerant as compared with that of the second cylinder 35 and then a discharging amount of oil accumulated there is restricted to a minimum value. Accordingly, lubrication of each of the portions within the compressor 25 is superior and the compressor 25 is stably operated.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a heating and cooling system that combines a refrigeration cycle and a refrigerant heater.

0003

[Prior Art] In general, a heat pump type air-conditioning system, which has a refrigeration cycle composed of a compressor, an indoor heat exchanger, an outdoor heat exchanger, an expansion valve, etc., uses a refrigerant after heat radiation in an indoor heat exchanger during heating. After reducing the pressure with an expansion valve, the outdoor heat exchanger absorbs atmospheric heat, vaporizes it, and sends it to the compressor. In such a heat pump type, the refrigerant receives heat from the atmosphere in an outdoor heat exchanger and vaporizes it.
When the outside air temperature is low, there is a drawback that the heating capacity decreases even though it is originally necessary to increase the heating capacity. For this reason, conventionally, there is a refrigerant-heating type air-conditioning/heating device in which a refrigerant heater is added to the heat pump type refrigeration cycle to improve the heating capacity. In an air-conditioning/heating machine that operates refrigerant heating and a heat pump at the same time, there is an example in which a two-cylinder compressor 1 is used, as shown in the refrigeration cycle configuration in FIG. The main components of this air conditioner include a two-cylinder compressor 1, a four-way valve 3, an indoor heat exchanger 5, and an outdoor heat exchanger 7.
, a refrigerant heater 9, and an expansion valve 11 as various valves.
These include a two-way valve 13, a flow control valve 15, a check valve 17, and the like. This compressor 1 has a first cylinder 19 and a second cylinder 2.
1 and operated simultaneously by one motor 23.

[0004] In a heating and cooling system having such a configuration,
During heating, when refrigerant heating and heat pump are operated simultaneously, the refrigerant flows from the compressor 1 to the four-way valve 3 to the indoor heat exchanger 5, and after leaving the indoor heat exchanger 5, it branches into two. ,
One side passes through the refrigerant heater 9 to the first cylinder 1 of the compressor 1.
9, and the other passes through the expansion valve 11 and the outdoor heat exchanger 7 to the second
It flows into the cylinder 21. At this time, the two-way valve 13 is in an open state, the flow control valve 15 is in a wide open state, and there is virtually no pressure loss. Further, when only the heat pump is operated without operating the refrigerant heater 9, the two-way valve 13 is closed. At this time, the refrigerant does not circulate through the refrigerant heater 9. During cooling, the refrigerant flows in the order of compressor 1 → four-way valve 3 → outdoor heat exchanger 7 → expansion valve 11 → indoor heat exchanger 5 → four-way valve 3 → compressor 1. At this time as well, the two-way valve 13 is closed, and no refrigerant flows into the refrigerant heater 9.

In such a configuration, when the refrigerant heater 9 is in operation, the suction line on the refrigerant heater 9 side becomes high pressure, so the first cylinder 19 is connected to the second cylinder for the refrigerant heater 9. 21 is used for the outdoor heat exchanger 7, that is, for heat pump operation. In addition, two-way valve 13
When the refrigerant heater 9 is closed and the refrigerant heater 9 is not operated, the pressure in the suction line on the refrigerant heater 9 side becomes lower than that on the outdoor heat exchanger 7 side, so that the refrigerant comes to pass through the check valve 17. That is, the heat pump operation is performed using the two cylinders 19 and 21.

[0006]

[Problems to be Solved by the Invention] By the way, if we consider the case where the above-mentioned air-conditioning system performs simultaneous operation of refrigerant heating during heating and the heat pump, as is clear from the Mollier diagram of the refrigeration cycle shown in FIG. In the case of the refrigerant heating operation shown by A, there is almost no compression process compared to the heat pump operation shown by the broken line B, so the refrigerant vapor at the inlet of the compressor 1 has a high pressure and a small specific volume, and the refrigerant flow rate is low even with the same cylinder capacity. If the heat pump side is set to 1, the number is overwhelmingly 3 to 10. As the refrigerant flow rate increases, the discharge amount of oil present in the compressor 1 as lubricating oil also increases. When the amount of oil discharged increases, compressor 1
This may adversely affect the lubrication of various parts of the compressor 1, and in the worst case, the sliding parts may be galled, ultimately leading to a fatal failure of the compressor 1 such as locking.

However, in the conventional air-conditioning system, the motor 23 of the compressor 1 is generally arranged above, and the first and second cylinders 19 and 21 are arranged below. , the relative positions of these cylinders 19 and 21 relative to each other are not particularly taken into consideration; therefore,
When the first cylinder 19 on the refrigerant heater 9 side with a large refrigerant flow rate is arranged at the lower side, the lubricating oil accumulates on the first cylinder 19 side, and the amount of oil discharged together with the large amount of refrigerant is discharged. increases, causing the problems described above.

[0008] Therefore, an object of the present invention is to suppress the amount of oil discharged from the compressor.

[Configuration of the invention]

0010

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a first cylinder and a second cylinder each having two suction ports and one discharge port and operating simultaneously corresponding to each suction port. an indoor heat exchanger installed indoors, an outdoor heat exchanger installed outdoors, each indoor heat exchanger and outdoor heat exchanger, a discharge port of the compressor, and one of the compressors. a switching valve connecting the suction port, an expansion valve provided on a pipe connecting the indoor heat exchanger and the outdoor heat exchanger, and a refrigerant provided between the pipe and the other suction port of the compressor. and a heating device, wherein the compressor has first and second cylinders arranged in a vertical relationship with each other, and the first cylinder arranged below is connected to the outdoor heat exchanger. On the side, a second cylinder arranged above was connected to the refrigerant heater side, respectively.

[0011]

[Operation] With this configuration, a large amount of the oil that exists as lubricating oil in the compressor accumulates in the first cylinder located below, but this first cylinder is equipped with an outdoor heat exchanger with a small refrigerant discharge amount. Since the refrigerant heater that discharges a large amount of refrigerant is connected to the second cylinder located above, the amount of oil discharged together with the refrigerant is kept small, and poor lubrication is prevented.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a refrigeration cycle configuration of a heating and cooling system according to an embodiment of the present invention. The components are described in the order in which the refrigerant flows during heating: a two-cylinder compressor 25, a four-way valve 27 as a switching valve, and an indoor heat exchanger 29.
It is. The compressor 25 has a first cylinder 33 and a second cylinder 35 housed in a compressor case 31, and includes one discharge port 37 and two suction ports 39 and 41. It is assumed that both cylinders 33 and 35 have the same cylinder volume and are operated simultaneously by the motor 43. motor 43
The cylinders 33 and 35 are connected by a motor shaft 45, and the motor shaft 45 is rotatably supported by a main bearing 47. In the compressor 25 configured in this way, the motor 43 is arranged above, and the cylinders 33 and 35 are arranged below. It is set in.

The discharge port 37 of the compressor 25 and the four-way valve 27 are connected by a pipe 49, and the four-way valve 27 and the indoor heat exchanger 29 are connected by a pipe 51. The refrigerant that has exited the indoor heat exchanger 29 flows through a pipe 53 and is then branched into two systems at a branching part 55, one of which goes to the refrigerant heater 59 side through a pipe 57, and the other goes to the outdoor heat exchanger 63 through a pipe 61. flows to the side. The refrigerant heater 59 includes a refrigerant heating heat exchanger 65 and a burner section 67. An expansion valve 69 is provided in the pipe 61, and this expansion valve 69 functions to lower the pressure of the refrigerant to an evaporation pressure at which heat can be absorbed from the atmosphere during operation of the heat pump.

A two-way valve 71 is provided in the piping 57 on the upstream side of the refrigerant heater 59, and this two-way valve 71 is used when the refrigerant heater 59 is not used when the heat pump is operated only during heating, or when the refrigerant is heated during cooling. The flow path is closed when the container 59 is not used. The refrigerant leaving the refrigerant heater 59 flows into a pipe 73, and this pipe 73 is connected to the suction port 41 of the second cylinder 35 located on the main bearing 47 side of the compressor 25. Outdoor heat exchanger 6
3 and the four-way valve 27 are connected by a pipe 75, and the four-way valve 2
7 and the suction port 39 of the first cylinder 33 located on the distal end side of the motor shaft 45 of the compressor 25 are connected by a pipe 77 .

In the above configuration, when the heating capacity is large, the refrigerant heating and the heat pump are operated simultaneously, but in this case, the two-way valve 71 is in an open state. Refrigerant heater 59
The refrigerant vapor that exits is under high pressure and is sent to the second cylinder 35 via the pipe 73. On the other hand, outdoor heat exchanger 6
The refrigerant vapor exiting the refrigerant 3 has a low pressure and is sent to the first cylinder 33 via the pipe 75, the four-way valve 27, and the pipe 77. The refrigerant on the suction side of the second cylinder 35 on the refrigerant heating side has a higher pressure than the refrigerant in the first cylinder 33 on the outdoor heat exchanger 63 side, and therefore has a smaller specific volume. Therefore, for cylinders with the same capacity, at the same rotation speed,
The second cylinder 35 on the refrigerant heating side has a much larger refrigerant flow rate than the first cylinder 33. The refrigerant sent out from these cylinders 33 and 35 flows out into the compressor case 31 and then passes through the discharge port 37 to the pipe 4.
9 is discharged.

On the other hand, the lubricating oil stored in the compressor 25 is moved by gravity to the first cylinder 3 located below.
It tends to accumulate on the 3rd side. However, as described above, the flow rate of refrigerant in the first cylinder 33 is considerably smaller than that in the second cylinder 35, and therefore, the discharge amount of the oil accumulated here can be minimized. By reducing the amount of oil discharged from the compressor 25, each part within the compressor 25 is well lubricated, the compressor 25 operates stably, and reliability as an air-conditioning device increases.

[0018]

Effects of the Invention As explained above, according to the present invention, the second
By connecting the first cylinder, which is located at the bottom where oil tends to accumulate, to the outdoor heat exchanger side where the refrigerant flow rate is low, the amount of oil discharged from the compressor can be minimized during heating. The reliability of the heating and cooling device can be increased.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a refrigeration cycle showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of a refrigeration cycle showing a conventional example.

FIG. 3 is a Mollier diagram in a refrigeration cycle.

[Explanation of symbols]

25 Two-cylinder compressor 27 Four-way valve (switching valve) 29 Indoor heat exchanger 33 First cylinder 35 Second cylinder 37 Discharge port 39, 41 Inlet 53, 61 Piping 59 Refrigerant heater 63 Outdoor heat exchanger 69 Expansion valve

Claims (1)

[Claims] Claim 1: A compressor having two suction ports and one discharge port, and a first cylinder and a second cylinder that operate simultaneously corresponding to each suction port, and an indoor heat exchanger installed indoors. an outdoor heat exchanger installed outdoors; a switching valve connecting each of the indoor heat exchangers and the outdoor heat exchanger to a discharge port and one suction port of the compressor; and the indoor heat exchanger. and an outdoor heat exchanger; and a refrigerant heater provided between the piping and the other suction port of the compressor, the heating and cooling device comprising: In this case, the first and second cylinders are arranged in a vertical relationship with each other, the first cylinder arranged at the bottom is placed on the outdoor heat exchanger side, and the second cylinder arranged at the top is placed on the refrigerant heating side. A heating and cooling device characterized by being connected to each side of the container.