JP2013178049A - Air conditioner - Google Patents

Abstract

An air conditioner that improves the comfort and reliability of an air conditioner that uses a flammable refrigerant as the refrigerant of the air conditioner and that reduces running costs.
A reservoir for enclosing flammable refrigerant in an air conditioner comprising a compressor, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger, and storing excess refrigerant during operation of the air conditioner. Is provided between the outdoor heat exchanger and the decompression device, and an air combustor is provided on the air inflow side of the outdoor heat exchanger to burn the combustible refrigerant sealed in the air conditioner as fuel and warm the air. It was set as the structure which connected the solenoid valve for refrigerant | coolants supply for enclosing a combustible refrigerant | coolant in the said reservoir, the gas part of the said reservoir, and the said combustor for air via the solenoid valve for combustion.
[Selection] Figure 1

Description

  The present invention relates to an air conditioner, and more particularly to an air conditioner including a combustor using a combustible refrigerant as a refrigerant used in the air conditioner and using the combustible refrigerant as a fuel.

  In recent years, many types of air conditioners mainly composed of a heat pump type have been put on the market in which the range of operable air temperature during cooling operation and heating operation has further expanded. In particular, with regard to the outside air temperature during heating operation, heating operation is possible even in a cold region of -20 ° C to -25 ° C.

  In such an air conditioner, a refrigerant heating type air conditioner that performs heating operation by heating and evaporating the refrigerant with a combustion heat source such as oil or gas is known for further increasing the heating capacity and improving the reliability. For example, there is Patent Document 1.

  This air conditioner includes an oil refrigerant heater that burns oil to heat the refrigerant, an outdoor heat exchanger that exchanges heat between the outdoor air and the refrigerant, and an indoor heat exchange that exchanges heat between the refrigerant and the indoor air. An air conditioner, a compressor that circulates the refrigerant, a switching valve that switches the refrigerant circulation path to either the outdoor heat exchanger or the petroleum refrigerant heater, an outside air temperature sensor that detects the outside air temperature, and the outside air temperature sensor An operation control means for switching between a heat pump operation and a refrigerant heating operation is provided by switching the switching valve in accordance with the outside air temperature signal. When the outside air temperature is low, the air conditioner switches to perform a heat pump operation when the outside air temperature is high, and performs a refrigerant heating operation when the outside air temperature is low, according to the outside temperature signal from the outside temperature sensor. However, since the evaporation temperature of the air conditioner can be kept high, it is possible to realize a high heating capacity at a low outside air temperature and to reduce a running cost at the time of heating.

Japanese Patent No. 4046828

  However, in the air conditioning apparatus described above, since petroleum is used as the fuel for the refrigerant heater, the reservoir and the refrigerant heater for storing the oil used as the fuel for the refrigerant heater in the air conditioner or outside the air conditioner are used. A supply device for supplying oil as fuel is required, and oil as fuel is also required separately. For this reason, there is a problem that not only the equipment as an air conditioner becomes large and the manufacturing cost increases, but also the cost of oil as a fuel is necessary, and the running cost also increases.

  Further, in the above prior art, since it is not configured to use a refrigerant heater that uses petroleum as fuel during the cooling operation, the cooling operation is performed only by the conventional heat pump operation, and at a low outside air temperature. At the time of starting, the liquid refrigerant easily returned to the compressor, increasing the burden on the compressor, and reducing the reliability of the air conditioner.

  The object of the present invention is to provide an air conditioner that solves the above problems, improves the comfort and reliability of an air conditioner that uses a flammable refrigerant as the refrigerant of the air conditioner, and reduces running costs at a low cost. That is.

  To achieve the above object, the present invention provides an air conditioner configured by connecting a compressor, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger via a refrigerant pipe. A combustor that warms the heat exchanger; a flammable refrigerant is enclosed in the refrigerant pipe; a refrigeration cycle is formed by circulation of the flammable refrigerant; the combustor is supplied with the flammable refrigerant; During the heating operation, the combustor uses the combustible refrigerant to warm the outdoor heat exchanger.

  In addition, a combustion solenoid valve provided in a refrigerant pipe that includes a reservoir for storing excess refrigerant between the outdoor heat exchanger and the pressure reducing device, and that connects the combustor and the reservoir. It is desirable that the flammable refrigerant is supplied from the reservoir to the combustor by opening.

  Moreover, it is desirable that a refrigerant supply solenoid valve is provided in the refrigerant pipe connected to the reservoir, and that the flammable refrigerant is supplied to the reservoir by opening the refrigerant supply electromagnetic valve.

  In addition, when the outdoor air temperature is equal to or lower than a preset temperature during the heating operation, the combustor performs an operation for heating the outdoor heat exchanger. On the other hand, when the outdoor air temperature is higher than the preset temperature, the combustor It is desirable not to perform the operation of warming the outdoor heat exchanger according to.

  The combustor is preferably provided on the air inflow side of the outdoor heat exchanger.

  When the refrigerant amount determining means in the refrigerant pipe and the refrigerant amount determining means determine that the refrigerant amount in the refrigerant pipe is equal to or less than the set value, the refrigerant supply solenoid valve is opened to And a cylinder for supplying a flammable refrigerant.

  According to the present invention, the temperature of the air flowing into the outdoor heat exchanger acting as an evaporator during heating operation can be increased by the air combustor, so that the liquid to the compressor at the start-up of the air conditioner While returning can be prevented and the reliability of the air conditioner can be improved, not only the outdoor heat exchanger can be prevented from frosting at a low outside air temperature but also the heating operation can be performed without reducing the efficiency of the air conditioner. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a refrigerant circuit figure showing the structure of the air conditioning apparatus in Example 1. FIG. It is an operation | movement flowchart figure which shows an example of the heating operation of the air conditioning apparatus in Example 1. FIG. It is a refrigerant circuit figure showing the structure of the air conditioning apparatus in Example 2. FIG. It is an operation | movement flowchart which shows an example of the heating operation of the air conditioning apparatus in Example 2. FIG. It is a refrigerant circuit figure showing the structure of the other air conditioning apparatus in Example 2. FIG. It is a refrigerant circuit figure showing the structure of the further another air conditioning apparatus in Example 2. FIG. It is a refrigerant circuit figure showing the structure of the further another air conditioning apparatus in Example 2. FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a refrigerant circuit diagram showing the configuration of the air-conditioning apparatus according to the first embodiment of the present invention. The air conditioner according to the present embodiment sequentially includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an outdoor expansion valve 4, an indoor expansion valve 6, and an indoor heat exchanger 7 that can be switched between a cooling operation and a heating operation. A refrigerant circuit is formed by pipe connection, and a combustible refrigerant (for example, propane) is sealed in the air conditioner. The outdoor heat exchanger 3 and the indoor heat exchanger 7 are respectively provided with an outdoor fan 8 and an indoor fan 9 so that air can flow so that heat can be exchanged with the refrigerant flowing into each heat exchanger.

  On the upstream side of the air 22 flowing into the outdoor heat exchanger 3, an air combustor 10 is provided that uses a combustible refrigerant enclosed in an air conditioner as fuel to heat the inflow air 22. ing. In addition, a reservoir 5 is provided between the outdoor expansion valve 4 and the indoor expansion valve 6 for separating gas and liquid and storing excess refrigerant that is unnecessary for the operation of the air conditioner. The refrigerant supply solenoid valve 12 is connected so as to supply the refrigerant sealed in the air conditioner, and the gas space part at the top of the reservoir 5 is connected so that the fuel can be supplied to the air combustor 10. A combustion solenoid valve 11 for supplying and shutting off fuel to the air combustor 10 is provided. The compressor 1, the four-way valve 2, the outdoor expansion valve 4, the indoor expansion valve 6, the outdoor fan 8, the indoor fan 9, the air combustor 10, the combustion electromagnetic valve 11, and the refrigerant supply electromagnetic valve 12 are controlled. An output signal of an outside air temperature detecting means 21 (for example, a thermistor) that is connected by a signal line so as to be able to communicate with the device 20 and detects the temperature of the air flowing into the outdoor heat exchanger 3 is input to the operation control device 20. Yes.

  Next, an operation method when the air conditioner is operated in the heating mode will be described. FIG. 2 is an operation flowchart illustrating an example of the heating operation of the air-conditioning apparatus according to the first embodiment of the present invention. When a heating operation start signal is output by a remote controller of the indoor unit and the operation control device 20 receives the heating operation start signal, the outdoor fan 8 and the indoor fan 9 start operation at a predetermined rotational speed, and the combustion electromagnetic The valve 11 is opened, and the combustible refrigerant gas sealed in the refrigerant circuit as fuel is introduced into the air combustor 10, and the operation of the air combustor 10 is started. When the operation of the air combustor 10 is started, the air 22 flowing into the outdoor heat exchanger 3 is warmed and flows into the outdoor heat exchanger 3 when passing through the air combustor 10.

  Here, the air passing through the air combustor 10 has been described as being heated. However, the present invention is not limited to this, and the outdoor heat exchanger 3 may be directly heated as will be described later. In the operation flowchart of FIG. 2, when the heating operation signal is received, the combustion solenoid valve 11 is opened to start the operation of the air combustor 10. However, the outside air temperature is lower than the set temperature during the heating operation. In the case where the outdoor heat exchanger 3 by the air combustor 10 is warmed, and when the outdoor air temperature is higher than the set temperature, the outdoor heat exchanger 3 by the air combustor 10 is The warming operation may not be performed.

  Next, in order to circulate the refrigerant in the refrigerant circuit, the compressor 1 is operated at a predetermined rotational speed, the four-way valve 2 is switched to the heating mode, and the heating operation is started. Next, after a predetermined time has elapsed, the outside air temperature flowing into the air combustor 10 is compared with a predetermined value α ° C. (for example, 5 ° C.), and if the outside air temperature is higher than the predetermined value α ° C., the air The combustion combustor 10 is stopped, the combustion solenoid valve 11 is closed, and the heating operation is continued by the control of the normal heating operation. When the outside air temperature is a predetermined value α ° C. or less, the air combustor 10 The heating operation is continued by controlling the normal heating operation while continuing the operation.

  As described above, in the air conditioner of the present invention, the temperature of the air 22 flowing into the outdoor heat exchanger 3 that acts as an evaporator at the start of the heating operation is increased using the air combustor 10, so that the evaporation The amount of heat exchange in the cooler increases, it becomes possible to prevent liquid return at the start of heating operation, and the reliability of the compressor 1 can be improved. Further, the air combustor 10 is used to reduce the temperature of the air flowing into the outdoor heat exchanger 3 acting as an evaporator against a frosting phenomenon on the outdoor heat exchanger 3 that is likely to occur during heating operation with a low outside air temperature. Since it can prevent by making it higher than the temperature which frost formation generate | occur | produces, the comfort of an air conditioning apparatus can also be improved. Furthermore, since the combustible refrigerant | coolant enclosed in the refrigerant circuit is used as a fuel of the air combustor 10, compared with combustors, such as oil and gas, the structure which stores combustion fuel is not required. Since no fuel cost is required, an inexpensive system can be constructed.

  Here, in the air conditioner of the present invention, the flammable refrigerant enclosed in the refrigerant circuit is used as the fuel for the air combustor 10, and therefore, if the air combustor 10 is continuously used, the flammability in the refrigerant circuit is maintained. There arises a problem that the efficiency of the refrigeration cycle decreases due to a decrease in refrigerant. Therefore, when the amount of refrigerant is detected such as detecting the liquid refrigerant in the reservoir 5 and the amount of refrigerant is reduced, that is, a combustible refrigerant is enclosed in the connection portion of the solenoid valve 12 for refrigerant supply attached to the reservoir 5. If the cylinder is connected, it is possible to automatically fill the refrigerant circuit with refrigerant by controlling the opening and closing of the refrigerant supply solenoid valve 12, and the efficiency of the refrigeration cycle is reduced due to lack of refrigerant. Can be prevented. That is, when the refrigerant quantity judging means judges that the refrigerant quantity in the refrigerant pipe is less than or equal to the setting, the refrigerant supply solenoid valve 12 is opened and the combustible refrigerant is supplied from the cylinder to the reservoir 5. is there.

  FIG. 3 is a refrigerant circuit diagram showing the configuration of the air-conditioning apparatus according to the second embodiment of the present invention. In this figure, the same reference numerals as those in FIG. 1 are the same. In the air conditioner of the present invention, the compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the outdoor expansion valve 4, the reservoir 5, the indoor expansion valve 6, and the indoor heat exchanger that can be switched between cooling operation and heating operation. Combustible refrigerant (for example, propane) is enclosed in a refrigerant circuit configured by sequentially connecting the pipes 7 and 7, the middle of the pipe connecting the outdoor expansion valve 4 and the reservoir 5, the outdoor heat exchanger 3 and the four-way valve. The refrigerant combustor 13 uses a combustible refrigerant enclosed in the air conditioner as fuel to heat the refrigerant in the bypass circuit so as to connect the middle of the pipe connecting the two. And a combustion expansion valve 14 for adjusting the amount of refrigerant introduced into the refrigerant combustor 13. The rest is the same as the refrigerant circuit shown in FIG. That is, in FIG. 3, a refrigerant pipe (bypass circuit) connected in parallel with the refrigerant pipe in which the outdoor heat exchanger 3 is installed is provided, and a refrigerant combustor 13 for warming the refrigerant is provided in the refrigerant pipe (bypass circuit). It is installed and a combustible refrigerant is supplied to the refrigerant combustor 13, and the refrigerant from the indoor heat exchanger 3 flows to the outdoor heat exchanger 3 via the decompression device (outdoor expansion valve 4) during the heating operation. The refrigerant combustor 13 is configured to be warmed by flowing to the combustor 13.

  Next, an operation method when the air conditioner is operated in the heating mode will be described. FIG. 4 is an operation flowchart illustrating an example of the heating operation of the air-conditioning apparatus according to the second embodiment of the present invention. When a heating operation start signal is output by a remote controller of the indoor unit and the operation control device 20 receives the heating operation start signal, the outdoor fan 8 and the indoor fan 9 start operation at a predetermined rotational speed, and the combustion electromagnetic The valve 11 is opened to introduce the combustible refrigerant gas sealed in the refrigerant circuit as fuel into the refrigerant combustor 13, and the operation of the refrigerant combustor 13 is started. Next, in order to circulate the refrigerant in the refrigerant circuit, the compressor 1 is operated at a predetermined rotational speed, the four-way valve 2 is switched to the heating mode, and the heating operation is started. Here, the openings of the outdoor expansion valve 4 and the combustion expansion valve 14 are closed or closed so that most of the refrigerant flows through the combustion expansion valve 14 immediately after the heating operation is started. Control is performed so that the opening of the outdoor expansion valve 4 is gradually opened so that the transient liquid refrigerant does not return to the compressor suction side as time elapses in the heating operation. Next, after a predetermined time has elapsed, the outside air temperature flowing into the outdoor heat exchanger 3 is compared with a predetermined value α ° C. (for example, 5 ° C.), and if the outside air temperature is higher than the predetermined value α ° C., the refrigerant The combustion combustor 13 is stopped, the combustion solenoid valve 11 is closed, and the heating operation is continued by controlling the normal heating operation. When the outside air temperature is equal to or lower than the predetermined value α ° C., the refrigerant combustor 13 The heating operation is continued by controlling the normal heating operation while continuing the operation. Further, the opening degree of the combustion expansion valve 14 at this time is controlled so as to control the degree of refrigerant superheat at the outlet of the refrigerant combustor 13 or the degree of refrigerant superheat on the discharge side of the compressor 1.

  As described above, in the air conditioner of the present invention, the amount of refrigerant flowing into the outdoor heat exchanger 3 acting as an evaporator at the start of the heating operation is suppressed, and the amount of heat exchange in the evaporator is kept low. Since the refrigerant is reliably evaporated by the refrigerant combustor 13, it is possible to prevent liquid return to the compressor that is likely to occur at the time of starting the heating operation at a low outside air temperature, thereby improving the reliability of the compressor 1. be able to. Moreover, in order to suppress the heat exchange amount in an evaporator low also with respect to the frost phenomenon to the outdoor heat exchanger 3 which is easy to generate | occur | produce at the time of heating operation with low outdoor temperature, the amount of frost formation to the outdoor heat exchanger 3 is also suppressed. It is greatly reduced and the comfort of the air conditioner can be improved. Furthermore, since the combustible refrigerant enclosed in the refrigerant circuit is used as the fuel for the refrigerant combustor 13, it does not require a structure for storing the combustion fuel as compared with the combustor such as oil or gas. Since no fuel cost is required, an inexpensive system can be constructed.

  Here, even when the refrigerant combustor 13 is connected in series in the middle of the pipe connecting the outdoor heat exchanger 3 and the four-way valve 2 as shown in FIG. It does not depart from the scope of the present invention. That is, a combustible refrigerant is supplied to the refrigerant combustor 13, and the refrigerant from the indoor heat exchanger 3 flows into the refrigerant combustor 13 during the heating operation and is warmed by the refrigerant combustor 13 before being compressed. 1 flows.

  Also, as shown in FIG. 6, when the refrigerant combustor 13 is connected in series in the middle of the pipe connecting the four-way valve 2 and the indoor heat exchanger 7, it is discharged by the compressor 1 during heating operation. Since the temperature of the gas refrigerant can be increased at once with the refrigerant combustor 13, the heating start-up speed can be increased, and thus the comfort of the air conditioner can be improved. Since the liquid refrigerant that returns without being evaporated from the indoor heat exchanger 7 at the time of startup or the like can be heated and evaporated by the refrigerant combustor 13, the liquid return to the compressor 1 at the time of startup is prevented. Therefore, the reliability of the compressor 1 can be improved.

  Further, as shown in FIG. 7, when the refrigerant combustor 13 is connected in series in the middle of the pipe connecting the four-way valve 2 and the compressor 1, both the cooling operation and the heating operation are evaporated from the evaporator at the start-up. Since the liquid refrigerant that returns without being heated can be heated and evaporated by the refrigerant combustor 13, it is possible to prevent the liquid from returning to the compressor 1 at the time of start-up, and the reliability of the compressor 1 can be improved. Can be improved.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 Outdoor expansion valve 5 Reservoir 6 Indoor expansion valve 7 Indoor heat exchanger 8 Outdoor fan 9 Indoor fan 10 Air combustor 11 Combustion solenoid valve 12 Refrigerant supply solenoid valve 13 Refrigerant combustor 14 Combustion expansion valve 20 Operation control device 21 Outside air temperature detection means

Claims (8)

In an air conditioner configured by connecting a compressor, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger via a refrigerant pipe,
A combustor for heating the outdoor heat exchanger;
A flammable refrigerant is enclosed in the refrigerant pipe, and a refrigeration cycle is formed by circulating the flammable refrigerant.
The combustor is supplied with the combustible refrigerant, and the outdoor heat exchanger is heated by the combustor using the combustible refrigerant during heating operation. In the air conditioning apparatus according to claim 1,
A reservoir for storing excess refrigerant between the outdoor heat exchanger and the pressure reducing device;
An air conditioner characterized in that the combustible refrigerant is supplied from the reservoir to the combustor by opening a solenoid valve for combustion provided in a refrigerant pipe connecting the combustor and the reservoir. apparatus. In the air conditioning apparatus according to claim 1 or 2,
The refrigerant pipe connected to the reservoir is provided with a refrigerant supply solenoid valve, and the refrigerant is supplied to the reservoir by opening the refrigerant supply solenoid valve. Harmony device. In the air conditioning apparatus according to claim 1 or 2,
When the outside air temperature is equal to or lower than a set temperature during the heating operation, an operation is performed to warm the outdoor heat exchanger by the combustor,
When the outside air temperature is higher than the set temperature, an operation of heating the outdoor heat exchanger by the combustor is not performed. In the air conditioning apparatus according to claim 1 or 2,
The air conditioner characterized in that the combustor is provided on the air inflow side of the outdoor heat exchanger. In the air conditioning apparatus according to claim 3,
Means for determining the amount of refrigerant in the refrigerant pipe;
A cylinder for opening the refrigerant supply solenoid valve and supplying the flammable refrigerant to the reservoir when the refrigerant quantity judging means judges that the refrigerant quantity in the refrigerant pipe is below the set value; An air conditioner characterized by that. In an air conditioner configured by connecting a compressor, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger via a refrigerant pipe,
A refrigerant pipe connected in parallel with the refrigerant pipe where the outdoor heat exchanger is installed;
The refrigerant pipe includes a combustor for warming the refrigerant,
A flammable refrigerant is enclosed in the refrigerant pipe, and a refrigeration cycle is formed by circulating the flammable refrigerant.
The combustor is supplied with the combustible refrigerant. During heating operation, the refrigerant from the indoor heat exchanger flows to the outdoor heat exchanger through the decompression device, and flows into the combustor, thereby causing the combustion. An air conditioner that is warmed by a vessel. In an air conditioner configured by connecting a compressor, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger via a refrigerant pipe,
Comprising a combustor for warming the refrigerant in the refrigerant pipe between the outdoor heat exchanger and the four-way valve;
A flammable refrigerant is enclosed in the refrigerant pipe, and a refrigeration cycle is formed by circulating the flammable refrigerant.
The combustor is supplied with the combustible refrigerant, and during heating operation, the refrigerant from the indoor heat exchanger flows into the combustor, and is heated by the combustor and then flows into the compressor. Air conditioner.