JPH04278149A - Cooling and heating device - Google Patents

Abstract

PURPOSE:To set up continuous and wide variable capability range by a method wherein a cylinder having a high volume is connected to an outdoor heat exchanger through one suction port and another cylinder having a low volume is connected to a refrigerant heater through the other suction port. CONSTITUTION:Since a volume of the second cylinder 30 at a refrigerant heater to which refrigerant having a high suction pressure of a compressor 25 and having a low specific volume is larger than that of the first cylinder 29 at a heat pump at a suction side of the compressor 25 in correspondence with a specific volume ratio of both refrigerants, discharged amounts of refrigerant from the cylinders 29 and 30 are approximately equal to each other, heating capabilities are approximately equal to each other and then a high heating capability under a concurrent operation can be sufficiently attained. As the refrigerant heater 53 is stopped, a heat pump operation utilizing the outdoor heat exchanger 57 under an operation of the first cylinder 29 is carried out. However, a volume of the first cylinder 29 is high and a sufficient heating capability is provided, so that a wide variable range of capability can be attained at a low heating capability side.

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 shown 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, each cylinder 19, 21 has the same volume and is 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] However, with the above configuration, although high heating capacity can be ensured by operating refrigerant heating and the heat pump simultaneously, when only the heat pump is operated to ensure low heating capacity, Since two cylinders 19 and 21 are used, there is a limit to the lower limit on the low heating capacity side, and there is a portion that overlaps with the heating capacity variable range in simultaneous operation of refrigerant heating and heat pump, making it difficult to operate efficiently. do not have.

Therefore, in heat pump operation, if a cycle configuration is adopted in which only one cylinder is used, a region with a small heating capacity can be secured, and the check valve 17 and the check valve 1
The structure becomes simple as the piping provided with 7 is not required.

By the way, as can be seen from the Mollier diagram for the refrigeration cycle shown in FIG. 4, the cylinder on the refrigerant heating side sends out the refrigerant without compressing it much (see solid line A), whereas the cylinder on the heat pump side sends out the refrigerant without compressing it much. The compression ratio is extremely large (see broken line B). That is, when looking at the refrigerant on the suction side of the compressor 1, the pressure on the refrigerant heating side is higher and the specific volume is smaller. For this reason,
If the volumes of the two cylinders 19 and 21 of the compressor 1 are the same, the refrigerant flow rate will increase on the refrigerant heating side at a rate of approximately the specific volume ratio. Usually, the ratio of the refrigerant flow rate is about 1 to 1 on the heat pump side and 3 to 10 on the refrigerant heating side.

[0009] If the refrigerant flow rates in the two cylinders 19 and 21 differ greatly in this way, the following disadvantages occur. The heating capacity is approximately proportional to the sum of the refrigerant flow rates from the two cylinders, so if the volumes of the two cylinders are the same, most of the capacity will be covered by refrigerant heating with a large refrigerant flow rate. The capacity of the cylinder is also determined based on the refrigerant heating side, and the cylinder on the heat pump side will have almost no capacity under the same conditions. This makes it almost impossible to stop the refrigerant heater and use the heat pump to cover areas with low heating capacity. On the other hand, if the cylinder volume is set larger to match the heat pump side, the rotation speed of the compressor must be significantly reduced considering the heating capacity of the refrigerant heating side. Vibration becomes noticeable, causing noise and cracks in pipes.

[0010] The present invention has been made to solve the above-mentioned problems, and its object is to obtain a continuous and wide capacity variable range from low heating capacity to high heating capacity.

[Configuration of the invention]

0012

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has two cylinder parts each having two suction ports and one discharge port, and two cylinder parts that operate simultaneously corresponding to each suction port. A compressor, an indoor heat exchanger installed indoors,
an outdoor heat exchanger installed outdoors, a switching valve that connects each of the indoor heat exchangers and the outdoor heat exchanger to the discharge port and one suction port of the compressor, and a switching valve that connects the indoor heat exchanger and the outdoor heat An air-conditioning and heating system comprising: an expansion valve provided in a pipe connecting an exchanger; and a refrigerant heater provided between the pipe and the other suction port of the compressor. The volumes of the cylinder parts are different from each other, and the cylinder part with a large volume is connected to the outdoor heat exchanger side through the one suction port, and the cylinder part with a small volume is connected to the refrigerant through the other suction port. It is connected to a heater.

[0013]

[Effect] In this way, by reducing the volume of the cylinder connected to the refrigerant heater side with a low compression ratio, and increasing the volume of the cylinder connected to the outdoor heat exchanger side with a high compression ratio, the refrigerant can be heated. The refrigerant flow rate between the heat exchanger and the outdoor heat exchanger can be made almost the same, and even if only the outdoor heat exchanger is operated to ensure low heating capacity, the low heating capacity side is sufficiently covered, and the low heating capacity side is A wide range of continuous capacity variation can be obtained over a high heating capacity.

[0014]

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 26 as a switching valve, and an indoor heat exchanger 27.
It is. As shown in FIG. 2, the compressor 25 includes a first cylinder 29 with a large cylinder volume and a second cylinder 30 with a small cylinder volume housed in a compressor case 28.
It has one discharge port 31 and two suction ports 33 and 35. 34 is a suction cup, which is omitted in FIG. It is assumed that both cylinders 29 and 30 are operated simultaneously by a motor 37. The cylinder volume ratio of the first cylinder 29 and the second cylinder 30 is approximately equal to the ratio of the specific volumes of the refrigerant on the suction side of the compressor 25 on the heat pump side and on the refrigerant heating side. Reference numeral 39 is a motor shaft, and 41 is a main bearing.

The discharge port 31 of the compressor 25 and the four-way valve 26 are connected by a pipe 43, and the four-way valve 26 and the indoor heat exchanger 27 are connected by a pipe 45. The refrigerant that has exited the indoor heat exchanger 27 flows through a pipe 47 and is then branched into two systems at a branching part 49, one of which goes to the refrigerant heater 53 through a pipe 51, and the other goes to the outdoor heat exchanger 57 through a pipe 55. flows to the side. The refrigerant heater 53 includes a refrigerant heating heat exchanger 59 and a burner section 61. An expansion valve 63 is provided in the pipe 55, and this expansion valve 63 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 65 is provided in the piping 51 on the upstream side of the refrigerant heater 53, and this two-way valve 65 is used when the refrigerant heater 53 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 vessel 53 is not used. The refrigerant leaving the refrigerant heater 53 flows into a pipe 67, which is connected to the suction port 35 of the compressor 25. The outdoor heat exchanger 57 and the four-way valve 26 are connected by a pipe 69, and the four-way valve 26 and the suction port 33 are connected by a pipe 71.

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 65 is in an open state. Refrigerant heater 53
The refrigerant that exits is under high pressure because it is not throttled.
The second cylinder 30, which has a smaller volume, continues through the piping 67.
sent to. On the other hand, the refrigerant that has exited the outdoor heat exchanger 57 is a low-pressure vapor, and is sent to the first cylinder 29 having a large volume through the piping 69, the four-way valve 26, and the piping 71. The refrigerant vapor sent into the second cylinder 30 is slightly compressed due to its high pressure, and then is discharged into the compressor case 28 . Furthermore, the low-pressure refrigerant vapor sent into the first cylinder 29 is compressed to a high-pressure state and discharged into the compressor case 28 .

Here, the volume of the second cylinder 30 on the refrigerant heating side into which the refrigerant having a high pressure and a small specific volume flows into the suction side of the compressor 25 is different from the volume of the second cylinder 30 on the refrigerant heating side into which the refrigerant having the same low pressure and a large specific volume flows. Since the volume of the first cylinder 29 on the heat pump side is made larger in accordance with the specific volume ratio of both refrigerants on the suction side of the compressor 25, each cylinder 29,
The amount of refrigerant discharged from the refrigerant 30 is approximately equal, and if this refrigerant flow rate is taken into consideration, the heating capacity of both units is approximately equal, and a high heating capacity can be sufficiently obtained during simultaneous operation. From this state, when the refrigerant heater 53 is stopped,
Only the heat pump using the outdoor heat exchanger 57 is operated by the operation of the first cylinder 29, but as mentioned above, the first cylinder 29 has a large volume and sufficient heating capacity, so even if the heat pump is operated only, the heating will be low. A wide capacity variable range can be obtained on the capacity side, and by combining refrigerant heating and simultaneous operation of the heat pump and using both of them depending on the heating capacity, a continuous and wide capacity variable range from low heating capacity to high heating capacity can be achieved. will be obtained.

Furthermore, since the volume of the second cylinder 30 on the refrigerant heating side is made small, the rotational speed of the compressor 25 can be maintained at a desired level without lowering it in accordance with the first cylinder 29 on the heat pump side. Vibration of the machine 25 can be prevented, noise generation, pipe cracking, etc. can be prevented.

[0021]

As explained above, according to the present invention, the compressor is a two-cylinder compressor having two different cylinder volumes, and the refrigerant on the suction side of the compressor has a high pressure and a small specific volume. By reducing the volume of the cylinder connected to the side, and increasing the volume of the cylinder connected to the outdoor heat exchanger side, where the pressure of the refrigerant is low and the specific volume is large, when the refrigerant heating and heat pump are operated simultaneously, two The flow rate of the refrigerant discharged from the cylinder can be made almost equal, and the heat pump side can also exhibit almost the same heating capacity as the refrigerant heating side, so that when the heating capacity is low,
Even if the refrigerant heater is stopped and only the heat pump is operated, the low heating capacity side can be sufficiently covered, and a continuous and wide capacity variable range from low heating capacity to high heating capacity can be obtained.

[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 partial cross-sectional view showing essential parts of the compressor used in the refrigeration cycle of FIG. 1;

FIG. 3 is a configuration diagram of a refrigeration cycle showing a conventional example.

FIG. 4 is a Mollier diagram in a refrigeration cycle.

[Explanation of symbols]

25 Two-cylinder compressor 26 Four-way valve (switching valve) 27 Indoor heat exchanger 29 First cylinder (cylinder part) 30 Second cylinder (cylinder part) 31 Discharge port 31 33, 35 Inlet 47,55 Piping 53 Refrigerant heater 57 Outdoor heat exchanger 61 Expansion valve

Claims (1)

[Claims] [Claim 1] A compressor having two suction ports and one discharge port, and two cylinder sections that operate simultaneously corresponding to each suction port, and an indoor heat exchanger installed indoors; an outdoor heat exchanger installed outdoors, a switching valve that connects each of the indoor heat exchangers and the outdoor heat exchanger to the discharge port and one suction port of the compressor, and a switching valve that connects the indoor heat exchanger and the outdoor heat An air-conditioning and heating system comprising: an expansion valve provided in a pipe connecting an exchanger; and a refrigerant heater provided between the pipe and the other suction port of the compressor. The volumes of the cylinder parts are different from each other, and the cylinder part with a large volume is connected to the outdoor heat exchanger side through the one suction port, and the cylinder part with a small volume is connected to the refrigerant through the other suction port. A heating and cooling device characterized by being connected to a heater.