KR100274460B1 - Heat-cooling system structure and heat-cooling operation method of heat pump type air conditioner - Google Patents

Abstract

PURPOSE: Cooling/heating system structure of a heat pump type air conditioner is provided to maintain a system regular by sucking and discharging refrigerant from a liquid receiver without regard to conversion of cooling/heating mode. CONSTITUTION: A cooling/heating system of a heat pump type air conditioner includes: a compressor(101) for compressing refrigerant; an indoor heat exchanger(102) for condensing the compressed refrigerant into liquid refrigerant; an expansion valve(103) expanding the condensed liquid refrigerant into two-phase refrigerant including gas and liquid phase; an outdoor heat exchanger(104) evaporating the two-phase refrigerant into gas phase refrigerant; a four-way valve(105) for feeding the compressed refrigerant to the indoor or outdoor heat exchanger; and a liquid receiver(108) formed on a refrigerant flow path of the expansion valve and the outdoor heat exchanger to obtain the remaining amount of refrigerant in a low-temperature heating mode. The liquid receiver has regular inlet and outlet even though refrigerant flow is changed in cooling/heating mode of a system. Therefore, the circulating amount of refrigerant is kept regular and the system is run regularly.

Description

Heat-cooling system structure and heat-cooling operation method of heat pump type air conditioner

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner. In particular, in a cooling and heating system of a heat pump type air conditioner employing a receiver, the amount of refrigerant circulating in the system is always stabilized even when the inlet / outlet of the receiver is fixed during the switching of the air conditioning mode. The present invention relates to a structure of a heating / cooling system of a heat pump type air conditioner and to a method of operating the same.

As shown in FIG. 1, a conventional heat pump type air conditioner includes a compressor 1 for compressing a refrigerant and an indoor heat exchanger 2 for condensing the refrigerant compressed from the compressor 1 in a liquid refrigerant state (or outdoors). A heat exchanger), an expansion valve 3 for expanding the liquid refrigerant condensed through the indoor heat exchanger 2 (or an outdoor heat exchanger) into a two-phase refrigerant (gas phase + liquid phase), and expansion through the expansion valve 3. The outdoor heat exchanger 4 (indoor heat exchanger) for evaporating the converted two-phase refrigerant into the gaseous phase refrigerant, and the refrigerant compressed from the compressor 1 according to the presence or absence of a power supply, are used as the indoor heat exchanger 2 or the outdoor heat exchanger ( 4) it consists of four sides (5) for sending to the side.

In addition, the indoor heat exchanger (2) and the outdoor heat exchanger (4) is provided with an indoor fan (6) and an outdoor fan (7) to forcibly introduce air to the indoor heat exchanger (2) or outdoor heat exchanger (4) side. To do that.

When the operation of the heat pump type air conditioner in the state configured as described above is a heating mode, the refrigerant flows into the compressor 1 and is compressed. At this time, the four sides 5 are through the indoor heat exchanger 2 side. Refrigerant compressed from) is introduced into the indoor heat exchanger (2) and condensed in the liquid refrigerant state, the liquid refrigerant condensed from the indoor heat exchanger (2) is expanded to the two-phase refrigerant through the expansion valve (3), The two-phase refrigerant expanded through the expansion valve (3) is introduced into the outdoor heat exchanger (4) to evaporate in the gas phase, and again into the compressor (1) to repeat the above process.

At this time, the indoor cold air forced into the indoor heat exchanger (2) by the indoor fan (6) absorbs condensation heat from the refrigerant flowing through the indoor heat exchanger (2) and discharges it back to the room, and performs heating. The outdoor air forced into the outdoor heat exchanger 4 by the outdoor fan 7 is taken out of the refrigerant flowing through the outdoor heat exchanger 4 and discharged to the outdoor air in a state where the temperature is lowered.

When the operation of the heat pump type air conditioner is in the cooling mode, the four sides (5) are opened to the outdoor heat exchanger (4), and the refrigerant flows from the compressor (1) to the outdoor heat exchanger (4) to the expansion valve (3) to the indoor heat exchanger. (2) The cooling is performed while circulating in order, and the above process is repeated.

However, in the low temperature heating operation of the system, since the circulation amount of the refrigerant is smaller than that of the standard heating operation, the receiver 8 is adopted in the heat pump type air-conditioning system as shown in FIG.

Since the receiver 8 is also suitable for securing the amount of excess refrigerant in a system in which the output of the compressor is variable in the inverter air conditioner and the refrigerant circulation amount is variable, the receiver 8 is also applied to a cycle in which a variable compressor is applied.

3, the inlet / outlet is fixed, and the end of the inlet tube 8a comes to the upper part of the receiver 8, and the end of the outlet tube 8b is the receiver 8 of FIG. It is designed to come to the bottom of the) and is configured to discharge the liquid by separating the gas liquid even if the liquid refrigerant having bubbles at the inlet of the receiver 8 is mixed.

If bubbles are discharged together when the refrigerant is discharged from the receiver 8, the expansion mechanism such as a capillary tube or the expansion valve 3 does not work properly due to the bubbles, and thus the cycle becomes unstable as a whole.

On the other hand, when the receiver 8 is applied to the heat pump type air conditioner, the flow of the refrigerant at the time of cooling and heating is opposite to each other, so that the liquid is always discharged from the outlet of the receiver 8 even if the flow of the refrigerant is changed. For this purpose, the two ends of the inlet tube 8a and the outlet tube 8b of the receiver 8 must be employed.

In addition, since the receiver 8 'needs to be installed in front of the expansion valve 3 or an expansion device such as a capillary tube, in order to share the receiver 8' during cooling and heating, the expansion valve 3 for cooling before and after the receiver 8 'is shared. ') And a heating expansion valve (3 ") must be installed respectively.

Accordingly, power is applied to the four sides 5 during the normal operation of the heating of the system to switch to the heating mode, and the cooling expansion valve 3 'is completely opened, and the heating expansion valve 3' is appropriately controlled.

At this time, the refrigerant is compressed and discharged in a state of high temperature and high pressure through the compressor (1), and flows into the indoor heat exchanger (2) through the four sides (5).

The refrigerant introduced into the indoor heat exchanger (2) heats up the condensation heat in the room and liquefies, and then flows into the receiver (8 ') through a fully opened cooling expansion valve (3').

The liquid refrigerant filled in the receiver 8 'is discharged by pressure, expanded under reduced pressure through a heating expansion valve 3 ", converted into a low-temperature, low-pressure two-phase refrigerant, and then flows into the outdoor heat exchanger 4 to evaporate. And, the evaporated refrigerant is repeated to flow into the compressor (1) through the four sides (5).

Here, when the heating operation is stopped in the system, two expansion valves 3 'and 3 "are opened to open and close the compressor 1 so that the load applied to the compressor 1 is small when the compressor 1 is restarted and the restarting is smooth. The difference between the high pressure and the low pressure is reduced. When the expansion valves 3 'and 3 "are opened during low temperature heating, the refrigerant moves into the low pressure side compressor 1, so that the viscosity of the oil in the compressor 1 becomes low. The lowered viscosity of the oil causes the compression part to be damaged.

During normal operation of the cooling system, power is removed from the four sides 5 to enter the cooling mode, the heating expansion valve 3 "is fully opened, and the cooling expansion valve 3 'is appropriately controlled.

At this time, the refrigerant is discharged in a compressed state at high temperature and high pressure through the compressor (1), and flows into the outdoor heat exchanger (4) through the four sides (5).

The refrigerant introduced into the outdoor heat exchanger (4) is introduced into the receiver (8 ') through a heat expansion valve (3 ") for heating after the heat is condensed and liquefied to the outside.

The liquid refrigerant filled in the receiver 8 'is discharged by pressure, expanded under reduced pressure through a cooling expansion valve 3', converted into a low-temperature, low-pressure two-phase refrigerant, and then introduced into the indoor heat exchanger 2. The evaporated refrigerant is introduced into the compressor 1 through the four sides 5 and the same operation is repeated.

However, when the bidirectional receiver is adopted in the heat pump type air conditioner as described above, since the refrigerant flows below the liquid level of the receiver, the fluid surface is always moved and becomes unstable, and the liquid refrigerant having air bubbles enters the receiver as cycle operating conditions change. If there is a possibility that bubbles are connected to the discharge pipe and discharged, this causes a malfunction of the expansion valve due to bubbles introduced into the inlet of the expansion valve as described above. The entire system becomes unstable and there is a problem that the manufacturing cost increases as the expansion valve is installed for cooling and heating, respectively.

The present invention has been devised in view of this point, and has two bypasses and four unilateral sides in a heat pump type air conditioner sharing one receiver and one expansion valve, so that the refrigerant is always irrespective of switching between cooling and heating modes. The purpose is to reduce the manufacturing cost while maintaining a stable system by flowing into the inlet of the receiver and discharged to the outlet.

1 is a cycle configuration diagram of a conventional heat pump type air conditioner.

2 is a cycle configuration diagram of a heat pump type air conditioner employing a conventional receiver.

3 is a block diagram of a general receiver.

4 is a cycle configuration diagram of a heat pump air conditioner according to the present invention.

Figure 5 is a flow chart when the heating operation stop of the heat pump air conditioner according to the present invention.

Figure 6 is a flow chart when starting the heating operation of the heat pump air conditioner according to the present invention.

7 is a first exemplary view showing another embodiment of the present invention.

8 is a second exemplary view showing another embodiment of the present invention.

*** Explanation of symbols for the main parts of the drawing ***

101: compressor 102: indoor heat exchanger

103: expansion valve 103 ': cooling expansion valve

103 ": Heating expansion valve 104: Outdoor heat exchanger

105: four sides 106: indoor fan

107: outdoor fan 108: receiver

108 ': bidirectional receiver 109: first detour

110: second detour 111: first unilateral side

112: second unilateral 113: third unilateral

114: fourth single side 115: solenoid valve

116: cooling capillary 116 ': heating capillary

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a configuration diagram of a heating and cooling cycle of a heat pump type air conditioner according to the present invention. The basic components, that is, the compressor 101, the indoor / outdoor heat exchanger 102/104, the expansion valve 103, and the four-sided valve 105 ), The receiver 108 and the like are the same as in the prior art, except that the refrigerant flow regulator is added between the indoor heat exchanger 102 and the outdoor heat exchanger 104 so that the refrigerant always remains irrespective of switching of the heating and cooling mode. It is to be introduced into the inlet of the receiver 108.

First, referring to the configuration, a compressor 101 for compressing a refrigerant, an indoor heat exchanger 102 (outdoor heat exchanger) for condensing the refrigerant compressed from the compressor 101 in a liquid refrigerant state, and the indoor heat exchanger (102) an expansion valve 103 for expanding the liquid refrigerant condensed through the (external heat exchanger) to a two-phase refrigerant (gas phase + liquid phase), and a two-phase refrigerant expanded through the expansion valve 103 to evaporate the gaseous refrigerant. Four sides 105 for sending the outdoor heat exchanger 104 (indoor heat exchanger) and the refrigerant compressed from the compressor 101 to the indoor heat exchanger 102 or the outdoor heat exchanger 104 depending on whether power is applied or not. And a receiver 108 formed on the refrigerant passage of the expansion valve 103 and the outdoor heat exchanger 104 to secure the amount of excess refrigerant during low temperature heating operation.

At this time, the receiver 108 is the end of the inlet pipe (108a) is located in the upper portion, the outlet tube (108b) uses a general type of receiver located in the lower portion, the indoor heat exchanger 102 and the outdoor heat exchanger ( 104 includes an indoor fan 106 and an outdoor fan 107 to force the air into the indoor heat exchanger 102 or the outdoor heat exchanger 104.

In addition, a certain portion between the indoor heat exchanger 102 and the expansion valve 103 in the refrigerant passage so that the refrigerant always flows into the inlet pipe 108a of the receiver 108, regardless of the switching of the heating and cooling mode of the system. A first detour 109 connecting a predetermined portion between the 108 and the outdoor heat exchanger 104, a predetermined portion between the expansion point 103 and the starting point of the first detour 109, and a first detour ( Indoor between the second detour 110 connecting the predetermined point between the arrival point of the 109 and the outdoor heat exchanger 104, and the starting point of the first detour 109 and the starting point of the second detour 110 A first single side 111 formed to open toward the heat exchanger 102, a second single side 112 formed to open toward the receiver 108 on the first bypass 109, and Between the arrival point of the first detour 109 and the arrival point of the second detour 110 is formed to open toward the receiver 108 The third single side 113 is provided, and the fourth single side 114 is formed on the second bypass 110 to open to the outdoor heat exchanger 104 side.

In this configuration, during the cooling operation of the system, the refrigerant is discharged in a compressed state from the compressor 101, passes through the four sides 105, enters the outdoor heat exchanger 104, and then condenses and liquefies. The refrigerant flows into the receiver 108 via the third single side 113.

At this time, the refrigerant flows to the front of the fourth short side 114 through the branch in front of the third short side 113, but is blocked by the fourth short side 114 and flows only toward the third short side 113. Done.

The liquid refrigerant introduced into the receiver 108 is discharged into a tube connected to the expansion valve 103, and the refrigerant is changed into a two-phase refrigerant of low pressure and low temperature while passing through the expansion valve 103.

The low-temperature two-phase refrigerant flows into the indoor heat exchanger 102 through the first single side 111, and at this time, the fourth single side side refrigerant is filled with the high temperature and high pressure refrigerant in front of the fourth single side side 114. It will not flow to the (114) side.

The refrigerant introduced into the indoor heat exchanger (102) is evaporated to change into gas, and introduced into the compressor (101) through the four sides (105) to repeat the above process while the system is operating.

At this time, the outdoor cold air forced into the outdoor heat exchanger 104 by the outdoor fan 107 is discharged back to the outdoor while the temperature of the refrigerant flowing through the outdoor heat exchanger 104 is lowered and the temperature is raised, The indoor air forced into the indoor heat exchanger (102) by the indoor fan (106) exchanges heat with the refrigerant flowing through the indoor heat exchanger (102) and discharges and cools the room in a state where the temperature is lowered.

In the heating operation of the system, two bypasses (109, 110) are passed through. First, the refrigerant is compressed and discharged from the compressor (101), passes through the four sides (105), enters the indoor heat exchanger (102), and then condenses, The liquefied and liquefied liquid refrigerant flows into the receiver 108 via the second one-sided 112 of the first bypass 109.

At this time, the inflow of the refrigerant to the expansion valve 103 is blocked by the first one-sided 111, the third that the refrigerant passing through the second one-sided 112 is flowing directly to the outdoor heat exchanger 104 side without expansion. The refrigerant is blocked by the one-sided side 113 and flows into the receiver 108 through the inlet tube 108a, which is always fixed, without passing directly through the expansion side 103.

The liquid refrigerant introduced into the receiver 108 is discharged through a tube connected to the expansion valve 103, and the refrigerant is converted into a low pressure low temperature two phase refrigerant through the expansion valve 103.

The low temperature two-phase refrigerant flows into the outdoor heat exchanger 104 via the fourth single side 114 of the second bypass 110, and at the front of the first single side 111 and the third single side 113. Since the high pressure liquid refrigerant is filled, the low pressure refrigerant flows back into the room by the first single side 111 and the inflow into the receiver 108 is blocked by the third single side 113.

The low pressure low temperature two phase refrigerant introduced into the outdoor heat exchanger 104 is evaporated and introduced into the compressor 101 again through the four sides 105, and the above process is repeated while the system is operating.

Here, when the heating operation of the system is stopped, as shown in FIG. 5, the compressor 101 is stopped while gradually closing the expansion valve 103 before stopping the compressor 101 and the indoor fan 106. The retreat of the refrigerant is blocked by the second short side 112 and the third short side 113 so that a large amount of liquid refrigerant is trapped in the receiver 108, and some of the refrigerant is connected to the indoor heat exchanger 102. It is trapped in the state of high temperature and high pressure between the discharge pipe connected to the compressor 101, a large amount of liquid refrigerant may be introduced into the compressor 101 of the low temperature when cold district heating operation is stopped, so that the viscosity of the oil is prevented and the compressor 101 at startup I can protect the mechanism part.

In addition, at the start of heating operation of the system, as shown in FIG. 6, the power is removed from the four sides 105 to switch to the cooling mode, and after a while, the power is applied again to return the four sides 105 to the heating mode. It is switched.

In this way, the high temperature and high pressure refrigerant trapped in the indoor unit flows into the compressor 101 to reduce the pressure difference before and after the compressor 101, thereby reducing the load of the compressor 101 at startup, and thus, in the compressor 101. By raising the temperature, the refrigerant dissolved in the compressor 101 is evaporated to restore the viscosity of the oil, the starting characteristics are improved, and the preheating time of the compressor 101 is shortened, which saves the time for the cycle to reach a steady state. The time to market will be faster.

Thereafter, the four sides 105 is switched back to the heating mode, and the compressor 101 is started while gradually opening the expansion valve 103.

The above is an embodiment according to the present invention, and another embodiment may be represented as shown in FIGS. 7 and 8.

First, FIG. 7 illustrates a case where the first single side 111 is replaced with the solenoid valve 115 in the embodiment of the present invention, and thus, one single side is replaced with the solenoid valve 115 or several single sides are provided. When the side is replaced by the solenoid valve 115, the effect according to the present invention can be achieved, and FIG. 8 is a case in which capillary tubes 116 and 116 'are used as the expansion mechanism instead of the expansion valve 103. The cooling capillary 116 and the heating capillary 116 ′ must be provided and used, and in this case, the effect of the present invention can be achieved.

As described above, in the present invention, the inlet side is used at the upper portion of the inlet and the outlet side at the bottom thereof, so that the inlet and outlet of the receiver are not changed even if the refrigerant flow is changed during cooling and heating of the system. Therefore, the amount of refrigerant circulation can be kept constant, so that the system can be stably operated and at the same time a single expansion mechanism is used, thereby reducing manufacturing costs.

In addition, by storing a large amount of liquid refrigerant in the receiver and dispersing part of the refrigerant in an indoor heat exchanger when the heating operation of the system is stopped, a large amount of liquid refrigerant flows into a low-temperature compressor, and the oil viscosity decreases when the cold heating operation is started. It is possible to prevent the damage of the mechanical part of the compressor, and by repeatedly controlling all sides when starting the heating operation of the system, the high temperature and high pressure refrigerant is temporarily introduced into the compressor, raising the temperature of the compressor and evaporating the refrigerant dissolved in the oil of the compressor. By restoring the viscosity of the oil to protect the mechanism of the compressor at startup, it is possible to shorten the time taken until the hot air discharge during startup.

Claims (12)

In the air-conditioning system of a heat pump type air conditioner having a compressor, a four-sided valve, an indoor heat exchanger, an expansion device, and an outdoor heat exchanger, An inlet tube having an end thereof located at an upper end thereof, and an outlet tube having an end thereof located at an lower thereof thereof, and a receiver for securing a predetermined amount of excess refrigerant; One expansion means for expanding the liquid refrigerant discharged from the receiver into a two-phase refrigerant; Refrigerant heating system structure of the heat pump type air conditioner comprising a refrigerant bypass means disposed on the flow path of the refrigerant so that the refrigerant is always introduced to the inlet side of the receiver regardless of the switching of the heating and cooling mode. The method of claim 1, The refrigerant bypass means includes a plurality of bypasses connecting a predetermined portion between the indoor heat exchanger and the expansion means in the flow path of the refrigerant, and a predetermined portion between the receiver and the outdoor heat exchanger; A heating and cooling system structure of a heat pump type air conditioner, characterized by comprising a plurality of guide members disposed on the flow path of the refrigerant so that the refrigerant flows only in one direction. The method of claim 2, The plurality of detours include: a first detour connecting a predetermined portion between the indoor heat exchanger and the expansion means in the refrigerant passage, and a predetermined portion between the receiver and the outdoor heat exchanger; A heating and cooling system structure for a heat pump type air conditioner, comprising: a predetermined portion between the expansion means and the starting point of the first detour, and a second detour connecting a predetermined portion between the arrival point of the first detour and the outdoor heat exchanger. The method of claim 2 or 3, The guide member includes a first guide member which is formed to be opened to the indoor heat exchanger side between the start point of the first detour and the start point of the second detour, A second guide member formed on the first bypass to open toward the receiver; A third guide member which is formed to be opened to the receiver side between the arrival point of the first detour and the arrival point of the second detour, And a fourth guide member formed on the second bypass to open to the outdoor heat exchanger. The method of claim 4, wherein The guide member is a heating and cooling system structure of a heat pump type air conditioner, characterized in that made of a check valve. The method of claim 2, The guide member is a heating and cooling system structure of a heat pump type air conditioner, characterized in that the combination of the check valve and the solenoid valve. The method of claim 1, The expansion means is a heating and cooling system structure of the heat pump type air conditioner, characterized in that the expansion valve or capillary. The method according to claim 1 or 7, In using the capillary tube as the expansion means, the heating and cooling system structure of a heat pump type air conditioner, characterized in that each provided with a heating capillary and a cooling capillary. In the cooling operation, opening the third single side to guide the liquid refrigerant condensed through the outdoor heat exchanger to the receiver; Discharging the refrigerant guided to the receiver to the expansion side; Opening the first one side to guide the two-phase refrigerant expanded through the expansion valve to the indoor heat exchanger side, In the heating operation, guiding the refrigerant to the receiver by opening the second one side to allow the liquid refrigerant condensed through the indoor heat exchanger to flow through the first bypass; Discharging the refrigerant guided to the receiver to the expansion side; Directing the refrigerant to the outdoor heat exchanger by opening the fourth one-sided side so that the expanded two-phase refrigerant flows through the expansion side to the second detour so that the condensed liquid refrigerant enters the receiver regardless of the switching of the cooling and heating modes. Heating and cooling operation method of the heat pump type air conditioner, characterized in that the flow to the side. The method of claim 9, When the first, second, third, and fourth single sides are opened, the refrigerant is cooled through the high temperature and high pressure refrigerant filled in the fourth single side when cooling, and the high temperature and high pressure refrigerant filled in the first single side when heating. A heating and heating operation method of a heat pump type air conditioner, characterized in that the backflow is prevented by itself. The method of claim 9, When the heating operation of the heat pump type air conditioner is stopped, the compressor is stopped by gradually closing the expansion valve before stopping the compressor and the indoor heat exchanger fan, so that the retardation of the refrigerant is blocked by the second and third single sides. The cooling and heating operation method of the heat pump type air conditioner characterized in that the liquid refrigerant is collected in the receiver. The method of claim 9, When the heating operation of the heat pump type air conditioner is started, the power is removed from all sides and switched to the cooling mode, and after a certain time, the high temperature and high pressure refrigerant contained in the indoor unit is switched to the heating mode by applying the power again. The heating and cooling operation method of the heat pump type air conditioner, characterized in that to reduce the pressure difference before and after the compressor to reduce the initial starting load and to increase the temperature in the compressor to restore the viscosity of the oil.