KR101126675B1 - Heat pump system using secondary condensation heat - Google Patents

Abstract

A heat pump system is disclosed that provides secondary condensation heat to the surface of the evaporator during heating operation so that dew condensation or frosting on the evaporator does not occur. To this end, a circulation pipe connecting the first heat exchanger and the expansion valve is composed of a first pipe connecting the surface of the first heat exchanger and the second heat exchanger, and a second pipe connecting the expansion valve with the surface of the second heat exchanger. It provides a heat pump system, characterized in that. According to the present invention, even when the outside air temperature is lowered, dew condensation or frost formation on the evaporator can be prevented. And even in winter, when the indoor and outdoor temperature difference is severe, defrosting can be performed on the surface of the evaporator using the vaporization heat generated from the condenser without a separate auxiliary heater.

Description

Heat pump system utilizing secondary condensation heat {HEAT PUMP SYSTEM USING SECONDARY CONDENSATION HEAT}

The present invention relates to a heat pump system, and more particularly, to a heat pump system that provides secondary condensation heat to the surface of the evaporator during heating operation so that dew condensation or frosting on the evaporator does not occur.

In general, a refrigerant circulation cycle of a heat pump system includes a compressor for compressing a refrigerant gas to a condensation pressure in a state of high temperature and high pressure, and an outdoor heat exchanger for condensing the refrigerant compressed in the compressor to a liquid phase by heat dissipation by air in the case of air cooling; An expansion valve for expanding the liquid refrigerant in the high temperature and high pressure state condensed in the outdoor heat exchanger to gaseous refrigerant in the low pressure state by throttling action, and using the latent heat of evaporation of the refrigerant while evaporating the refrigerant expanded in the expansion valve. It consists of an indoor heat exchanger for cooling the air blown by the heat exchange and also return the refrigerant gas to the compressor.

This heat pump system is a system in which the refrigerant is continuously changed from gas to liquid and liquid to gas during the refrigerant circulation cycle, and the heating and cooling operation is switched to all directions. The heat pump is a heating heat source. It is a system to make.

1 is a block diagram schematically illustrating a refrigerant circulation structure of a conventional heat pump cycle outdoor unit, and FIG. 2 is a view illustrating a piping structure of a conventional heat pump cycle outdoor unit.

As shown, the outdoor unit of the conventional heat pump cycle is provided with a refrigerant pipe 10 corrugated so as to exchange heat as the refrigerant flows therein, a heat radiation fin 20 provided on the outer periphery of the refrigerant pipe 10 to increase the heat transfer area, and It is composed of a refrigerant inlet pipe 31 and the refrigerant outlet pipe 32 connected to the inlet and outlet of the refrigerant pipe 10 to circulate the refrigerant. Here, the configuration of the compressor, the accumulator, the four-way valve and the like are omitted because they are general configurations.

On the other hand, in the heat pump system, the outdoor heat exchanger is frozen when the outdoor temperature falls below -5 ° C. in the heating mode, and thus, the indoor heating ability is significantly reduced. For this reason, the heat pump system necessarily implements a defrost mode that reverses the cycle at regular intervals so that the outdoor heat exchanger does not freeze during the heating mode. In this case, the refrigerant discharged from the compressor in the defrost mode flows into the refrigerant inlet pipe 31, and then heat exchanges while passing through the corrugated refrigerant pipe 10, and then circulates through the refrigerant outlet pipe 32 again to the indoor heat exchanger. It will perform the function.

As described above, the conventional heat pump system stops the operation of the heat pump to remove frost generated in the outdoor heat exchanger and uses a method such as an electric defrost or a hot gas defrost. All of these defrosting methods do not allow normal operation such as stopping the heat pump operation to perform defrosting, so that continuous and stable operation is impossible, and there is a problem in that operating efficiency is deteriorated.

Accordingly, an object of the present invention is to prevent defrosting and frost on the evaporator by performing defrosting operation on the evaporator by directly using the secondary condensation heat, which is the heat of vaporization generated from the condenser, without a separate auxiliary heater in winter. To provide a pump system.

In order to achieve the above object of the present invention, an embodiment of the present invention comprises a compressor, a first heat exchanger connected to the compressor, an expansion valve connected to the first heat exchanger, a second heat exchanger connected to the expansion valve. In the heat pump system, a circulation pipe connecting the first heat exchanger and the expansion valve is connected to the first pipe connecting the surface of the first heat exchanger and the second heat exchanger, and to connect the expansion valve to the surface of the second heat exchanger. Provided is a heat pump system comprising a second pipe.

In this case, an automatic control valve may be installed in the first pipe, and a third pipe may be installed between the automatic control valve and the expansion valve to flow the refrigerant discharged from the automatic control valve into the expansion valve.

According to the present invention, even when the outside air temperature is lowered, dew condensation or frost formation on the evaporator can be prevented. Accordingly, the heat pump system can be used even in areas where there is a lot of moisture in the air.

In addition, the present invention can perform a defrosting operation on the surface of the evaporator using the vaporization heat generated from the condenser without a separate auxiliary heater even in winter when the indoor and outdoor temperature difference is extreme. Accordingly, by performing a separate defrosting operation can be prevented from lowering the heating efficiency, it is possible to maximize the savings of operating costs.

1 is a flowchart illustrating a cycle of a conventional heat pump system.
2 is a view showing the piping of the evaporator of the conventional heat pump system.
Figure 3 is a schematic diagram for explaining a heat pump system according to an embodiment of the present invention.
4 is a configuration diagram illustrating a heat pump system according to FIG. 3.
5 is a schematic view for explaining a heat pump system according to another embodiment of the present invention.

Hereinafter, a heat pump system (hereinafter, referred to as a "heat pump system") using secondary heat of condensation according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic view for explaining a heat pump system according to an embodiment of the present invention.

Referring to FIG. 3, a heat pump system according to an embodiment of the present invention compresses, condenses, and expands gas refrigerant by high pressure compression with a compressor 100, and then selectively and positively circulates the refrigerant under high pressure. And a refrigeration cycle apparatus for repeatedly performing the evaporation process, the compressor 100, the first heat exchanger 200, the expansion valve 300, the second heat exchanger 400, and the first heat exchanger 200. And a first pipe 210 and a second pipe 220 connecting the expansion valve 300 to each other. At this time, the circulation pipe between the compressor 100 and the first heat exchanger 200, between the expansion valve 300 and the second heat exchanger 400, and between the second heat exchanger 400 and the compressor 100. (P) is installed. Here, as the circulation pipe, any pipe may be used as long as it is a pipe commonly used in the art.

Hereinafter, each component will be described in more detail with reference to the drawings.

First, the heat pump system according to an embodiment of the present invention includes a compressor 100.

The compressor 100 compresses the refrigerant into a state of high temperature and high pressure by endothermic action and discharges the refrigerant to the first heat exchanger 200. The refrigerant vapor generated by the compressor 100 is compressed in a cylinder.

If necessary, as shown in Figure 4, the inlet side of the compressor 100, the separator (accumulator, 110) may be connected to the circulation pipe. Here, the water separator 110 separates the refrigerant into a gas and a liquid before the refrigerant flows into the compressor 100, and serves to transfer only the gas to the compressor 100.

And the heat pump system according to the present invention includes a first heat exchanger (200).

The first heat exchanger 200 serves as a condenser that cools the refrigerant vapor compressed by the compressor 100 with a secondary fluid such as water or air during a heating operation, and condenses it into a liquid phase. Some of the generated heat of vaporization (hereinafter, referred to as 'primary heat of condensation') is transmitted to a secondary fluid such as indoor air or water.

Accordingly, the refrigerant passing through the first heat exchanger 200 provides the primary condensation heat to the secondary fluid such as indoor air or water through primary condensation heat exchange means (not shown) such as a fan, thereby providing one of the vaporization heat. It has some heat of vaporization except the heat of secondary condensation (hereinafter referred to as 'secondary heat of condensation').

More specifically, the first heat exchanger 200 has a structure that heat exchanges with the refrigerant passing through the first heat exchanger 200 while passing indoor air by a fan, or with the refrigerant of the first heat exchanger 200. A water pipe for circulating water may be installed to indirect heat exchange.

On the other hand, the first heat exchanger 200 serves as an evaporator to evaporate the refrigerant during the cooling operation. That is, in the heat pump system according to the present invention, the circulation direction of the refrigerant is reversed according to the case of cooling or heating.

In addition, the heat pump system according to an embodiment of the present invention includes a first pipe 210 and a second pipe 220.

The first pipe 210 and the second pipe 220 are generated from the first heat exchanger 200 so that dew does not form on the surface of the second heat exchanger 400 or frost is formed even when the outside air temperature decreases. The secondary condensation heat to be provided to the surface of the second heat exchanger 400, and is a circulation pipe connecting the first heat exchanger 200 and the expansion valve (300).

In detail, the first pipe 210 may allow the refrigerant discharged through the first heat exchanger 200 to indirectly exchange heat with the surface of the second heat exchanger 400. The surface of the heat exchanger 400 is connected.

The second pipe 220 connects the expansion valve 300 to the surface of the second heat exchanger 400 so that the refrigerant indirectly heat exchanged through the second heat exchanger 400 is discharged to the expansion valve 300. do.

Here, the first pipe 210 and the second pipe 220 may be any pipe as long as it is a pipe commonly used in the art.

As shown in FIG. 5, an automatic control valve 230 may be installed in the first pipe 210, and a third pipe 240 may be disposed between the automatic control valve 230 and the expansion valve 300. Can be installed. And a control unit (not shown) electrically connected to the automatic control valve 230 may be installed.

Specifically, the automatic control valve 230 is electrically connected to the control unit to the refrigerant introduced through the first pipe 210 by the control unit in any one of the second pipe 220 or the third pipe 240. It serves as a discharge, and can be used as a three-way valve.

If necessary, the third pipe 240 may be directly connected to the expansion valve 300 separately from the second pipe 220, or may be indirectly connected through the second pipe 220. When the third pipe 240 is connected to the second pipe 220, the second automatic control valve for blocking the refrigerant introduced into the second pipe 220 does not move in the direction of the second heat exchanger 400 ( Not shown) may be further installed. At this time, the second automatic control valve is electrically connected to the control unit. Here, when the refrigerant passing through the automatic control valve 230 flows into the third pipe 240, the second automatic control valve is sealed by the controller.

As such, the automatic control valve 230 discharges the refrigerant introduced into the second pipe 220 to reach the expansion valve 300 via the second heat exchanger 400 or immediately reaches the expansion valve 300. It is operated to discharge to the third pipe (240).

In addition, the heat pump system according to an embodiment of the present invention includes an expansion valve (300).

The expansion valve 300 is a device that makes the liquid refrigerant condensed in the first heat exchanger 200 to be easily evaporated, and decompresses the liquid refrigerant to a state that is easy to evaporate through a throttling process. . Accordingly, the liquid refrigerant discharged from the first heat exchanger 200 is expanded to the liquid refrigerant at low temperature and low pressure.

The expansion valve 300 is a kind of throttle valve, and has two functions, a pressure reduction action and a flow rate control action of the refrigerant.

As shown in FIG. 4, the expansion valve 300 includes a first expansion valve 310 into which the liquid refrigerant condensed in the second heat exchanger 400, which serves as a condenser in the cooling operation, and a first in the heating operation. It may be formed as a second expansion valve 320 in which the liquid refrigerant condensed in the heat exchanger 200 is introduced.

Specifically, the expansion valve 310 is used during the cooling operation, is connected to the inlet side of the first heat exchanger 200 by inflating the refrigerant transferred through the second heat exchanger 400 to the Inflow to the first heat exchanger (200). At this time, the solenoid valve and the check valve for opening and closing the inside of the pipe to both sides of the first expansion valve 310 is installed, the bypass tube is further installed in the pipe in which the first expansion valve 310 is installed. Here, the bypass pipe is provided with a check valve at one end to block the refrigerant conveyed in the reverse direction and to allow the refrigerant to be transferred when the first expansion valve 310 is not used. In addition, the second expansion valve 320 is used during the heating operation, and is connected to the inlet side of the second heat exchanger 400 to expand the refrigerant transferred through the first heat exchanger 200 to expand the first expansion valve. Inflow to the two heat exchanger (400). At this time, the solenoid valve and the check valve for opening and closing the inside of the pipe to both sides of the second expansion valve 320 is installed, the bypass tube is further installed in the pipe is installed the second expansion valve (320). Here, the bypass pipe is provided with a check valve at one end to block the refrigerant being conveyed in the reverse direction and to allow the refrigerant to be transferred when the second expansion valve 320 is not used.

In addition, the heat pump system according to an embodiment of the present invention includes a second heat exchanger (400).

The second heat exchanger 400 acts as an evaporator for evaporating the low temperature low-pressure liquid refrigerant in the low-temperature low-pressure state by the endothermic action during the heating operation, the refrigerant evaporated, Return to the compressor (100). At this time, the refrigerant inside the second heat exchanger 400 absorbs latent heat necessary for evaporation from the surroundings and continuously evaporates. Therefore, the refrigerant liquid and the refrigerant vapor coexist in the second heat exchanger 400.

The second heat exchanger 400 serves as a condenser to heat exchange the refrigerant vapor of the high temperature and high pressure transferred through the compressor 100 with the outdoor air during the cooling operation.

In a particular embodiment, the second heat exchanger 400 according to the present invention has a first coil (not shown) and a second coil (not shown) which indirectly heat exchange with each other. Here, the first coil receives the refrigerant through the circulation pipe (P) connected to the expansion valve 300, and discharges the refrigerant to the compressor (100). The second coil receives the refrigerant through the first pipe 210 and discharges the refrigerant to the second pipe 220.

As shown in FIG. 4, a receiver is disposed between the first heat exchanger 200 and the second expansion valve 320 and between the second heat exchanger 400 and the first expansion valve 310. , 800) may be installed. In other words, the receiver 800 is installed before passing through the expansion valves 310 and 320 of the refrigerant flow in the refrigeration cycle.

Specifically, the receiver 800 replenishes the insufficient refrigerant while temporarily storing the refrigerant introduced through the first heat exchanger 200 and the second heat exchanger 400 in the interior of the receiver 800. While temporarily storing the supplementary and the refrigerant serves as a kind of safety device to separate and transfer to the expansion valve (310, 320). Thus, the use of receiver 800 reduces the risk of refrigeration cycles. The receiver 800 is used in a refrigeration apparatus having most of the low pressure side rich or expansion valve type refrigerant control device.

Optionally, the heat pump system according to an embodiment of the present invention may further include a branch pipe (900).

As shown in FIG. 4, at one end of the pipe connected between the outlet side of the receiver 800 and the water separator 110, a branch pipe 900 having a smaller diameter than the pipe is branched, and the branch pipe ( The other side of the 900 is connected to one end of the pipe connected to the inlet side of the compressor (100). At this time, a solenoid valve 910 is further installed at one end of the branch pipe 900 to open and close the inside of the branch pipe 900 by a signal from the controller.

Here, the role of the branch pipe 900 is a safety device to prevent the overload by branching a predetermined amount of the refrigerant transported during the cooling operation, a large amount of refrigerant is introduced into the second heat exchanger 400 during the heating operation to freeze. This is a safeguard to prevent it from going fast.

In addition, the heat pump system according to an embodiment of the present invention may further include a temperature sensor (not shown) and a differential pressure sensor (not shown).

The temperature sensor measures an outside air temperature or a surface temperature of the second heat exchanger 400 during a heating operation, and is electrically connected to a controller to provide a measured temperature to the controller.

The differential pressure sensor measures an internal pressure of the second heat exchanger 400, and is electrically connected to the controller to provide the measured pressure to the controller.

When the temperature measured from the temperature sensor and the pressure measured from the differential pressure sensor are input to the controller, the controller controls the automatic control valve 230 by analyzing the measured temperature and the measured pressure. At this time, when the pressure input from the differential pressure sensor is analyzed to be higher than the pressure set in the controller, the controller stops the primary condensation heat exchange means installed in the first heat exchanger (200). This prevents secondary fluids such as indoor air or water from being circulated so that heat exchange between the secondary fluid and the first heat exchanger 200 does not occur. Accordingly, the refrigerant passing through the first heat exchanger 200 may have primary and secondary condensation heat, thereby providing the primary and secondary condensation heat to the surface of the second heat exchanger 400. In other words, the differential pressure sensor provides additional primary condensation heat to the surface of the second heat exchanger 400 when dew condensation or frosting is not prevented on the surface of the second heat exchanger 400 only by the secondary condensation heat. Play a role.

On the other hand, the control unit is electrically connected to each of the above-described devices, when the operation command is input through the power supply means the compressor 100, the first heat exchanger 200, expansion valve 300, the second heat exchanger 400 To operate. When the outside temperature is input from the temperature sensor or the internal pressure of the second heat exchanger 400 is input from the differential pressure sensor, the controller opens and closes the automatic control valve 230 according to the set contents.

Accordingly, the refrigerant passes through the compressor 100, the first heat exchanger 200, the expansion valve 300, the second heat exchanger 400 in sequence along the circulation pipe (P), the first heat exchanger ( Between the 200 and the expansion valve 300 is indirect heat exchange with the surface of the second heat exchanger (400).

If necessary, one side of the circulation pipe (P) may be provided with a circulation pump 600 for circulating the refrigerant through the circulation pipe (P).

As shown in FIG. 5, when the outside air temperature inputted to the controller through the temperature sensor according to the present invention is analyzed to be about 0 ° C. or less, or the pressure inputted to the controller through the differential pressure sensor is analyzed to 10% or more of the reference pressure. The control unit controls the automatic control valve 230 to allow the refrigerant passing through the automatic control valve 230 to be discharged to the first pipe 210 instead of the third pipe 240. In other words, when the pressure input to the controller through the differential pressure sensor is analyzed to 10% or less of the reference pressure, the controller controls the automatic control valve 230 so that the refrigerant passing through the automatic control valve 230 passes through the third pipe. Discharge to 240.

Accordingly, the coolant effectively removes frost by providing secondary condensation heat to the surface of the second heat exchanger 400. This operation allows the heat pump system to operate even in adverse weather conditions.

That is, by indirect heat exchange of the refrigerant having secondary heat of condensation with the surface of the second heat exchanger 400, the dew condensation generated by the difference between the surface of the second heat exchanger 400 and the outside air temperature during the evaporation of the refrigerant is large. You can block or minimize the idea of sex.

Therefore, the present invention does not require a separate defrosting operation to remove dew or frost generated on the surface of the second heat exchanger 400, and thus does not stop the operation of the heat pump system, thereby providing excellent heating efficiency. do.

Referring to the heating cycle of the heat pump system according to the present invention having the above components are as follows.

First, the refrigerant supplied to the compressor 100 and compressed and then discharged toward the first heat exchanger 200 is supplied to the first heat exchanger 200 along the circulation pipe P.

Then, the high-temperature, high-pressure gaseous refrigerant supplied to the first heat exchanger 200 is condensed while discharging heat to the water circulating along the indoor air and / or the water pipe and discharged to the first pipe 210. . That is, the high temperature and high pressure refrigerant discharged from the compressor 100 is condensed while being exchanged with air or water while passing through the first heat exchanger 200, whereby the room is heated.

Then, the refrigerant passing through the first pipe 210 is indirectly heat exchanged with the second heat exchanger 400 and then discharged to the expansion valve 300 along the second pipe 220.

Then, the refrigerant supplied to the expansion valve 300 is expanded and discharged toward the second heat exchanger 400.

The refrigerant having passed through the expansion valve 300 is supplied to the second heat exchanger 400 along a circulation pipe P installed between the expansion valve 300 and the second heat exchanger 400 to supply heat of outdoor air. After being absorbed and evaporated, it is discharged toward the compressor 100.

As such, the refrigerant absorbing the secondary condensation heat from the first heat exchanger 200 is secondary to the surface of the second heat exchanger 400 in the process of flowing along the first pipe 210 and the second pipe 220. Since the heat of condensation is provided, there is no fear of dew or frost on the surface.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that it is possible.

100: compressor 110: separator
200: first heat exchanger 210: first piping
220: second piping 230: automatic control valve
240: third pipe 300: expansion valve
310: first expansion valve 320: second expansion valve
400: second heat exchanger 800: receiver
900: branch pipe 910: solenoid valve
P: Circulation piping

Claims (4)

A compressor, a first heat exchanger having a primary condensation heat exchange means connected to the compressor and providing primary condensation heat to a secondary fluid in the room, an expansion valve connected to the first heat exchanger, and a second heat exchanger connected to the expansion valve. In the heat pump system comprising:
The circulation pipe connecting the first heat exchanger and the expansion valve connects the surfaces of the first heat exchanger and the second heat exchanger to provide a second heat exchanger with a refrigerant having secondary condensation heat except the primary condensation heat. A first pipe and a second pipe connecting the surface of the second heat exchanger to the expansion valve,
The expansion valve is used in a cooling operation and is connected to an inlet side of the first heat exchanger by a pipe to expand the refrigerant transferred through the second heat exchanger and introduce the first expansion valve into the first heat exchanger, and to use the heating operation. And a second expansion valve connected to an inlet of the second heat exchanger by a pipe and expanding the refrigerant transferred through the first heat exchanger to flow into the second heat exchanger.
The pressure input from the differential pressure sensor by analyzing the temperature sensor for measuring the outside temperature, the differential pressure sensor for measuring the internal pressure of the second heat exchanger, and the temperature measured from the temperature sensor and the pressure measured from the differential pressure sensor is a preset pressure If it is analyzed above, the control unit for stopping the primary condensation heat exchange means to provide the primary and secondary condensation heat to the second heat exchanger,
A separator connected to a circulation pipe connecting the second heat exchanger and the compressor and provided at an inlet side of the compressor;
A receiver provided between the first heat exchanger and the second expansion valve and between the second heat exchanger and the first expansion valve, and
One end is connected to one end of the pipe connected between the outlet side and the separator of the receiver, the other end is connected to one end of the pipe connected to the inlet side of the compressor, connected between the outlet side and the separator of the receiver And a branch pipe having a smaller diameter than the pipe. The method of claim 1,
The first pipe is provided with an automatic control valve, and a third pipe is installed between the automatic control valve and the expansion valve to flow the refrigerant discharged from the automatic control valve to the expansion valve,
The control unit is configured to open and close the automatic control valve by analyzing the temperature measured from the temperature sensor and the pressure measured from the differential pressure sensor. delete The method of claim 2,
And the control unit controls the automatic control valve so that the refrigerant flows into the third pipe when the pressure input from the differential pressure sensor is increased to 10% or less of the reference pressure.

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