KR100581566B1 - The method and device for sensing the surface of fluid in container for heatpump airconditioner with cooling and heating - Google Patents

Abstract

The present invention relates to a heat pump air conditioner for both heating and cooling, and more particularly, to detect a liquid level inside a sealed high pressure container provided as a surplus space for recovering and accommodating a part of a refrigerant circulating in the cycle. The present invention relates to a method for detecting a liquid level inside a container of a heat pump air conditioner for cooling and heating, and a method thereof, wherein the method is condensed into the inside of the high pressure container by a pressure difference between the internal pressure of the high pressure container and the refrigerant circulating in the cycle. Liquid refrigerant is introduced or discharged, and during the process, the liquid level is detected inside the high pressure vessel due to a rapid temperature drop as the refrigerant expands through the flow path forming the reference oil surface when the liquid refrigerant in the high pressure vessel is exceeded. Active in accordance with the various installation and operating conditions of the refrigeration system It is possible to optimally control the amount of refrigerant circulating in the interior of the claw, thereby improving the efficiency and performance of the refrigeration system.

High pressure vessel, flow path, branch flow path, open / close valve, expansion valve, temperature sensor

Description

The method and device for sensing the surface of fluid in container for heatpump airconditioner with cooling and heating}

1 is a schematic diagram of a refrigeration cycle schematically showing a configuration of a general air-conditioning combined heat pump air conditioner.

Figure 2 is a schematic diagram of a refrigeration cycle schematically showing the configuration of the air-conditioning combined heat pump air conditioner to which the present invention is applied.

Figure 3 is a system diagram showing a state in which the liquid refrigerant is filled in the high-pressure container according to the present invention.

Figure 4a, Figure 4b is an enlarged view showing the liquid level detection state inside the high-pressure container during the charging process of Figure 3;

5 is a system diagram showing a state in which the liquid refrigerant in the high-pressure container is discharged according to the present invention.

Figure 6a, Figure 6b is a schematic diagram showing a liquid level detection state inside the high-pressure container during the discharge process of FIG.

* Explanation of symbols for main parts of the drawings

1: compressor 2: 4-way valve

3: condenser 4: expansion mechanism

5: Evaporator 6: Indoor blower fan

7: Outside blower fan 8: High pressure vessel

9: 1st flow path 9a: 1st switching valve

9b: High pressure pipe 10: 2nd flow path

10a: 2nd on / off valve 11: branch circuit

12: Third flow path V1 to Vn: Expansion valve

T: first temperature sensor T1 to Tn: second temperature sensor

The present invention relates to a heat pump air conditioner for both heating and cooling, and more particularly, to detect a liquid level inside a sealed high pressure container provided as a surplus space for recovering and accommodating a part of a refrigerant circulating in the cycle. The present invention relates to a method for detecting liquid level inside a container of a heat pump air conditioner for cooling and heating and a device therefor.

1 is a schematic diagram showing the configuration of a general air-conditioning combined heat pump air conditioner.

The air-conditioning combined heat pump air conditioner includes a compressor (1), a four-way valve (2), an evaporator (5), an indoor blower fan (6), an expansion device (4), and a condenser (3) and an outdoor blower fan (7). It is composed of

The compressor 1 compresses the gaseous refrigerant of low temperature and low pressure sucked into the inside through the suction port and discharges the gas through the discharge port in a gas state of high temperature and high pressure.

The four-way valve (2) has two independent passages connecting the discharge port and the suction port of the compressor (1) to the evaporator (5) and the condenser (3), respectively, according to the mode of cooling operation and heating operation by the user's selection Switch the flow of refrigerant.

The evaporator (5) is located in the room, and in the cooling operation mode to perform the function of evaporating the low-temperature low-pressure liquid refrigerant in the gas state, and in the heating operation mode to condense the refrigerant of the high temperature and high pressure gas state into a liquid state of room temperature and high pressure In response to the change in enthalpy of the refrigerant, heat is exchanged with the surrounding air.

The indoor blower fan (6) facilitates the heat exchange action of the evaporator (5) and at the same time serves to generate the cold or warm air required for the room.

The expansion mechanism (4) has a function as a capillary (pressure) to reduce the low-temperature low-pressure liquid state of the liquid refrigerant at room temperature and high pressure is connected between the evaporator 5 and the condenser (3).

The condenser 3 is located outdoors, performs a condensation function during the cooling operation, has an evaporation function during the heating operation, and heat exchanges with the surrounding air, and the outdoor blower fan 7 is an indoor blower fan. Like (6), the condenser 3 has a function of promoting heat exchange.

On the other hand, the refrigeration cycle as described above is required to control the amount of refrigerant circulating in the cycle in accordance with various installation and operating conditions, as a surplus space for the control of the amount of refrigerant, the receiver is usually a sealed container (not shown) ) Is installed between the condenser 3 and the expansion mechanism 4.

However, the receiver has a problem that it is impossible to optimally control the amount of refrigerant more actively because it has only a simple function of passing the liquid refrigerant and stagnating only the gaseous refrigerant inside the device.

Accordingly, the present invention has been made to solve the conventional problems as described above, the object is the liquid oil level inside the sealed high-pressure container provided as a surplus space for recovering and accommodating a part of the refrigerant circulating the cycle It is possible to optimally control the amount of refrigerant actively circulating in the cycle according to the various installation and operating conditions of the refrigeration system, thereby improving the efficiency and performance of the refrigeration system.

In order to achieve the object of the present invention, in the heat pump combined air-conditioning and heating system, the liquid refrigerant condensed into the high-pressure vessel is introduced or discharged by the pressure difference between the internal pressure of the high-pressure vessel and the refrigerant circulating in the cycle. In the process, when the liquid refrigerant in the high pressure vessel exceeds the reference oil surface provided with a plurality of liquid refrigerant in the high pressure vessel by the rapid temperature drop as the refrigerant expands through the flow path forming the reference surface that the Provided are a method for detecting a liquid level inside a container of a heat pump air conditioner for dual cooling and heating.

In addition, the upper side of the high pressure vessel allows the pressure of the gaseous refrigerant of the high temperature and high pressure to be applied, the lower side of the high pressure vessel allows the pressure of the liquid refrigerant of the room temperature and high pressure to be applied, the flow path forming the reference surface is It is characterized in that the liquid refrigerant can be introduced into or discharged into the high pressure vessel through the lower side of the high pressure vessel by their pressure difference by connecting to the low pressure side.

In addition, a heat pump air conditioner combined with a heating and cooling system composed of a compressor, a four-way valve, a condenser, an expansion mechanism, and an evaporator, the sealed high pressure vessel; A first flow passage connecting a lower side of the high pressure vessel with a conduit and an expansion mechanism, and having a first opening / closing valve; A second flow path connecting an upper side of the high pressure container with a conduit between the compressor and the condenser and having a second on / off valve; Branch passages formed in plural in the vertical direction in the side portion of the high pressure vessel, and expansion valves formed on the respective passages; A third flow path connecting the branch flow path and a conduit between the evaporator and the compressor; The liquid level sensor inside the container of the air-conditioning and heat pump air conditioner, characterized in that the first and second temperature sensing sensors provided on the rear side branch flow path of the expansion valve and the conduit and the expansion mechanism, respectively. Is provided.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration of the liquid level detection method and apparatus inside the container of the air-conditioning combined heat pump air conditioner according to the present invention according to the embodiment.

1 is a system diagram of a refrigeration cycle schematically showing a configuration of a general air-conditioning combined heat pump air conditioner.

In general, the air-conditioning combined heat pump air conditioner includes: a compressor (1) for compressing a low-temperature low-pressure gaseous refrigerant sucked into the inside through a suction port and discharging it through a discharge port in a high-temperature high-pressure gas state;

It has two independent passages that connect the discharge port and the suction port of the compressor 1 to the evaporator 5 and the condenser 3, respectively, and switch the flow of refrigerant according to the mode of cooling operation and heating operation according to the user's choice. A valve 2;

It is located indoors, and in the cooling operation mode, the liquid refrigerant of low temperature and low pressure is evaporated to the gas state, and in the heating operation mode, the refrigerant enthalpy is performed by condensing the refrigerant of the high temperature and high pressure gas state into the liquid state of normal temperature and high pressure. An evaporator (5) adapted to exchange heat with ambient air in response to the change;

An expansion mechanism (4) connected between the evaporator (5) and the condenser (3) and having a function of capillary for depressurizing a liquid refrigerant of normal temperature and high pressure which is transferred from one side to a liquid state of low temperature and low pressure;

Located in the open air, it performs a condensation function during the cooling operation, and has a condenser (3) having an evaporation function during the heating operation and heat exchange with the surrounding air.

Here, reference numeral 6 denotes an indoor blower fan, and 7 denotes an outdoor blower fan.

In the air-conditioning combined heat pump air conditioner, the present invention is provided with a high-pressure container (8) sealed in the outdoor side, as shown in Figure 2, the high-pressure container (8) is connected to the high pressure and low pressure of the refrigeration cycle Therefore, due to their pressure difference, that is, the pressure relation, the condensed liquid refrigerant circulating in the cycle can be partially recovered and stored or supplied again. In addition, the liquid oil level inside the sealed high-pressure container 8 is provided. It is characterized in that it can be detected.

For this purpose, a first flow path 9 is formed which connects the high pressure pipe 9b between the lower side of the high pressure container 8 and the condenser 3 and the expansion mechanism 4; A second flow path (10) connecting the upper side of the high pressure container (8) and a conduit between the compressor (1) and the condenser (3) is formed; A third flow passage 12 connecting the side portion of the high pressure vessel 8 and a conduit between the evaporator 5 and the compressor 3 is formed.

As a means for opening and closing the first flow path 9 and the second flow path 10, first opening / closing valves 9a and second opening / closing valves 10a are provided on the flow paths, respectively.

In addition, as a means for detecting the liquid oil level inside the high-pressure container 8 during the process of inflow and discharge of the condensed liquid refrigerant to the high-pressure container 8 by the pressure relationship as described above, Branches (12) are formed with branch passages (11) which are connected in the vertical direction to the side portions of the high pressure vessel (8) to form a reference oil surface, and expansion valves (V1 to Vn) are provided on each branch passage (11). The second temperature sensor T1 to Tn is installed on the rear branch flow path 11 of the expansion valves V1 to Vn, and the condenser 3 and the expansion mechanism to which the first flow path 9 is connected. The first temperature sensor T is also provided in the high-pressure pipe 9b between (4).

Figure 3 is a system diagram showing a state in which a liquid refrigerant is filled in the high pressure vessel according to the present invention.

First, when the second on-off valve 10a of the second flow path 10 is closed, the internal pressure of the high pressure container 8 is set to P0 and the pressure acting on the high pressure container 8 through the first flow path 9. When P1 and the pressure acting on the high pressure vessel 8 through the second flow path 10 are P2 and the pressure acting on the third flow path 12 is P3, P2 becomes 0 and the remaining pressure relation is P1>. The liquid refrigerant condensed through the first flow path 9 at P0 > P3 flows into the high pressure vessel 8 and is filled.

During the filling process, as shown in FIG. 4A, when the liquid oil level inside the high pressure vessel 8 exceeds the branching flow passage 11, the liquid refrigerant inside the high pressure vessel 8 passes through the branch flow passage 11 at low pressure. The liquid refrigerant flows out to the negative side, and is expanded by the expansion valves V1 to Vn to cause a phase change.

At this time, the temperature is measured by the second temperature sensor T1 to Tn, and the measured temperature is the first temperature sensor T installed in the high pressure pipe 9b between the condenser 3 and the expansion mechanism 4. When the liquid refrigerant expands to cause a phase change as described above, a sudden temperature drop occurs, so that the liquid oil level inside the container is corresponding to the branch flow path (11). That is, it can be recognized that it is higher than the standard level.

However, as shown in FIG. 4B, when the liquid oil level inside the high pressure vessel 8 is lower than the corresponding branch flow path 11, that is, the reference oil surface, only the gaseous refrigerant flows to the low pressure portion through the branch flow path 11. Since the phase change by the expansion valves V1 to Vn is not accompanied, the temperature measured by the second temperature sensor T1 to Tn and the reference temperature measured by the first temperature sensor T It is possible to recognize that the liquid oil level inside the container is lower than the branch circuit 11, that is, the height of the reference oil level, because no large temperature change occurs.

5 is a system diagram showing a state in which the liquid refrigerant in the high-pressure container is discharged according to the present invention.

First, when the second opening / closing valve 10a of the second flow passage 10 is opened, the internal pressure of the high pressure vessel 8 is set to P0 and the pressure acting on the high pressure vessel 8 through the first flow passage 9. When the pressure acting on the high pressure vessel 8 through P1 and the second flow path 10 is P2 and the pressure acting on the third flow path 12 is P3, the pressure relation is P2> P1> P0> P3. The liquid refrigerant inside the high pressure container 8 is discharged through the first flow path 9.

During the discharge process, as illustrated in FIG. 6A, when the liquid oil level inside the high pressure vessel 8 is higher than the branch flow passage 11, that is, the reference oil surface, the liquid refrigerant inside the high pressure vessel 8 is the branch flow passage 11. It flows out to the low pressure side through the liquid refrigerant is expanded by the expansion valve (V1 ~ Vn) to cause a phase change.

At this time, the temperature is measured by the second temperature sensor T1 to Tn, and the measured temperature is the first temperature sensor T installed in the high pressure pipe 9b between the condenser 3 and the expansion mechanism 4. When the liquid refrigerant expands to cause a phase change as described above, a sudden temperature drop occurs, so that the liquid oil level inside the container is corresponding to the branch flow path (11). That is, it can be recognized that it is higher than the standard level.

However, as shown in FIG. 6B, when the liquid oil level inside the high pressure container 8 is lower than the corresponding branch flow path 11, that is, the reference oil surface, only the gaseous refrigerant flows to the low pressure side through the branch flow path 11. The temperature measured by the second temperature sensor T1 to Tn and the reference temperature measured by the first temperature sensor T are not accompanied by a phase change by the expansion valves V1 to Vn. It is possible to recognize that the liquid surface in the container is lower than the height of the branch circuit 11, that is, the reference surface, because no large temperature change occurs during the period.

As described above, the present invention enables to detect the liquid oil level inside the sealed high-pressure container provided as a surplus space for recovering and accommodating a part of the refrigerant circulating in the cycle, according to various installation and operating conditions of the refrigeration system. It is possible to optimally control the amount of refrigerant actively circulating in the cycle, thereby improving the efficiency and performance of the refrigeration system.

Claims (3)

In the air-conditioning combined heat pump air conditioner, Due to the pressure difference between the internal pressure of the high pressure vessel and the refrigerant circulating in the cycle, the liquid refrigerant condensed into the inside of the high pressure vessel is introduced or discharged, and in the process, a reference oil level having a plurality of liquid refrigerants inside the high pressure vessel is provided. The liquid level detection method of the inside of the container of the heating and air-conditioning combined heat pump air conditioner characterized in that the liquid level inside the high-pressure vessel can be detected by a sudden temperature drop as the refrigerant expands through the flow path forming the reference surface when exceeded. The method of claim 1, The upper side of the high pressure vessel allows the pressure of the gaseous refrigerant of high temperature and high pressure to be applied, the lower side of the high pressure vessel allows the pressure of the liquid refrigerant of normal temperature and high pressure to be applied, the flow path forming the reference surface is the low pressure side Method of detecting the liquid level inside the container of the air-conditioning combined heat pump air conditioner characterized in that the liquid refrigerant can be introduced into or discharged into the high-pressure container through the lower side of the high-pressure container by their pressure difference. . In the heat pump air conditioner for combined heating and cooling, which consists of a compressor, a four-way valve, a condenser, an expansion device, and an evaporator, A sealed high pressure vessel; A first flow passage connecting a lower side of the high pressure vessel with a conduit and an expansion mechanism, and having a first opening / closing valve; A second flow path connecting an upper side of the high pressure container with a conduit between the compressor and the condenser and having a second on / off valve; Branch passages formed in plural in the vertical direction in the side portion of the high pressure vessel, and expansion valves formed on the respective passages; A third flow path connecting the branch flow path and a conduit between the evaporator and the compressor; The liquid level sensor inside the container of the air conditioner of the heating and cooling combined heat pump, characterized in that the first and second temperature sensing sensor provided on the rear side branch flow path of the expansion valve and the conduit and the expansion mechanism, respectively.

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