JPS62123264A - Air-cooled heat pump type refrigeration cycle device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an air-cooled heat pump type refrigeration cycle device, and in particular, the present invention relates to an air-cooled heat pump type refrigeration cycle device, and in particular, to suppress build-up during heating, improve heating comfort, and improve cooling operation range at low outside temperatures. The present invention relates to an air-cooled heat pump type refrigeration cycle device suitable for.

[Background of the invention]

Conventionally, in the air-cooled heat pump type refrigeration cycle 1tvc, during heating, N frost is formed on the outdoor heat exchanger, and this is defrosted by a reverse cycle defrosting method or the like. However, during normal operation, the indoor heat exchanger acts as an evaporator, causing problems such as blowing cold air into the room and reducing heating capacity.

A conventional refrigeration cycle is shown in FIG.

FIG. 3 is a refrigeration cycle system diagram of a conventional air-cooled heat pump type air conditioner.

In Fig. 3, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger, 4 is an outdoor heat exchanger, 5V'i outdoor fan, 61
``T accumulator, 7 and 8 are check valves, and 9. Capillary tubes related to the 10-piece expander.During heating, the refrigerant flows in the direction of the solid arrow, acting as an indoor heat exchanger and 3-piece condenser, and dissipating heat. The indoor heat exchanger acts as a 4-place evaporator and an outdoor heat exchanger.

On the other hand, during defrosting operation, the cycle is the same as during cooling, which is the reverse cycle of heating, the refrigerant flows in the direction of the dashed arrow, the outdoor heat exchanger 4 acts as a condenser, defrosting is performed by Hovt gas, and indoor heat exchange is performed. It functions as a three-piece evaporator.

Conventionally, for example, as described in Japanese Patent Application Laid-Open No. 59-69667, a bypass circuit is provided on the refrigeration cycle flow path, and the outdoor heat exchanger is defrosted while performing heating operation using residual heat from heating. Air-cooled heat pump type air conditioners are known.

However, defrosting using the heat left over from indoor heating has a problem in that the defrosting ability is limited and the defrosting operation time becomes long.

Further, frosting progresses from the windward side of the heat exchanger fins, and consideration has not been given to the structure of the cycle during defrosting, since the amount of frosting on the windward side is large.

[Purpose of the invention]

Uninvented, this was done to solve the problems of the conventional technology mentioned above, and it has a cycle that suppresses frost formation during heating, a cycle that continues heating operation even during defrosting, and an expansion of the range of cooling operation at low outside temperatures. We provide mechanically superior air-cooled heat pump refrigeration cycle equipment that enables cycles such as
That is the purpose.

[Summary of the invention]

The configuration of the air-cooled heat pump type refrigeration cycle device according to the present invention includes at least a compressor, an outdoor heat exchanger, an indoor heat exchanger, an expander, and a refrigerant flow path connecting these devices. The outdoor heat exchanger is divided into an upstream heat exchanger and a downstream heat exchanger with respect to the air flow, and a flow path for dividing the refrigerant is connected to each heat exchanger, and the upstream heat exchange A first electromagnetic valve is provided in the flow path that is on the refrigerant inlet side during heating, and a first electromagnetic valve is provided in the flow path that is on the refrigerant inlet side during heating of the upstream heat exchanger from the compressor discharge gas flow path. A branch flow path connected to the downstream side of the first solenoid valve is provided, and a second solenoid valve is provided in this branch flow path.

Additionally, the idea behind developing the present invention is as follows.

In the conventional refrigeration cycle, the defrosting operation always had a negative effect on indoor heating, so in the present invention, first,
The heat exchanger and refrigeration cycle are designed to suppress frost formation on the outdoor heat exchanger, and then divide the circulating refrigerant to defrost the outdoor heat exchanger while performing heating operation. The composition was considered.

In the configuration of the present invention, by controlling the capacity of the outdoor heat exchanger, it is possible to adjust the refrigeration cycle during low outside temperature operation even in cooling operation.

In other words, focusing on the fact that frost buildup on outdoor heat exchangers generally progresses from the windward side, and the amount of frost buildup increases on the windward side, the outdoor heat exchanger is placed on the upstream side with respect to the air flow. Divided into the downstream side, and for each of these divided heat exchangers,
The refrigerant flow path is configured to divide the circulating refrigerant so that the refrigerant flows in parallel to both heat exchangers, and part of the gas discharged from the compressor is guided to the upstream heat exchanger. As a result, a hobut gas defrosting circuit is constructed, and these refrigerant flow paths are controlled using electromagnetic valves to form optimal flow paths during heating operation, defrosting operation, and cooling operation.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1, 2, and 4.
This will be explained with reference to FIGS. 10 to 10.

First, an embodiment of the present invention will be explained with reference to FIGS. 1, 4, 6, 7, and 8.

FIG. 1 is a refrigeration cycle system diagram of an air conditioner according to an embodiment of the present invention, FIG. 4 is a detailed configuration diagram of an outdoor heat exchanger section in each embodiment of FIGS. 1 and 2, and FIG. 6 is an explanatory diagram of the functional parts operation of each embodiment, FIG. 7 is an explanatory diagram of air temperature distribution in the outdoor heat exchanger section of each embodiment, and FIG. It is a line diagram.

The embodiment shown in FIG. 1 is an example of an air conditioner exclusively for heating, and is suitable for a unit used in a relatively high outside temperature range. In the figure, the same reference numerals as in FIG. 3 indicate parts equivalent to the prior art.

In Fig. 1, 11.12 indicates that the outdoor heat exchanger is connected to the upstream side (windward side) and the downstream side (upward side) with respect to the air flow indicated by the white arrow.
11 is a first heat exchanger on the upstream side, and 12 is a second heat exchanger on the downstream side. 13.14
is a flow path for dividing the refrigerant into the first heat exchanger 11 and the second heat exchanger 12.

16f'i, a first solenoid valve disposed in the flow path 13;
It is located in a flow path that is on the refrigerant inlet side with respect to the heat exchanger 11 during heating.

15 is branched from the compressor discharge gas flow path, and is connected to the flow path 13
A branch flow path 17 connected between the first solenoid valve 16 and the first heat exchanger 11 (downstream side of the first solenoid valve 16 during heating) is disposed in this branch flow path 15. a second solenoid valve;
18.19 is a capillary tube related to the expander provided in the flow path +3.14, and 20 is a flow rate adjustment capillary tube provided in the branch flow path 15.

The details of the configuration of the outdoor heat exchanger are shown in FIG. The first heat exchanger 11Y'i is a fin-and-tube type heat exchanger having a large number of fins Ila passing through a pipe 11b, and the second heat exchanger 12 is a fin-and-tube type heat exchanger having a large number of fins 12a passing through a pipe 12b. This is a fin-and-chave type heat exchanger.

As shown in FIG. 4, the first heat exchanger 11fi is located upstream with respect to the air flow indicated by the white arrow, and the second heat exchanger 12 is located downstream and disposed on the drain buff 25. . 2
3 shows frost that has built up on the first heat exchanger 11VC.

According to such a configuration, as shown in FIG. 7, during heating operation, the first heat exchanger 11 of the outdoor heat exchanger that functions as an evaporator performs cooling and dehumidification (■-■), and the second The heat exchanger 12 cools and dehumidifies (■→■). If this is shown on the psychrometric diagram of FIG. 8, with dry bulb temperature on the horizontal axis and absolute humidity on the vertical axis, cooling (tl) and dehumidification (χ1) in the first heat exchanger 11 are shown.
), that is, the amount of frost formation is large (■→■), and the cooling (tl) and dehumidification (χ2) in the second heat exchanger 12 has a small dehumidification or frost formation effect (■-■).

Therefore, defrosting can be performed on the first heat exchanger 11, resulting in the defrosting cycle shown in FIG. 1.

Next, the operation of the refrigeration cycle having such a configuration will be explained.

During heating operation VC, the refrigerant flows in the direction of the solid arrow.

The high-temperature, high-pressure refrigerant gas discharged from the compressor 1 is condensed in the indoor heat exchanger 3 to heat the room. The condensed refrigerant is divided into flow paths 13 and 14vc on the outdoor heat exchanger inlet side, and then flows into flow path 1.
3 is expanded by the capillary tube 18 through the first electromagnetic valve 16, enters the first heat exchanger 11 and evaporated, and the flow path 14 is expanded by the capillary tube 19 and is transferred to the second heat exchanger 12Vc. enters and evaporates.

The evaporated refrigerant gas passes through the Akiemulator 6 to the compressor 1.
to form a cycle. At this time, the second solenoid valve 1
7 is closed.

During defrosting operation, the refrigerant flows in the direction of the dashed arrow.

The refrigerant gas discharged from the compressor 1 is divided into the indoor heat exchanger 3 and the branch flow path 15, one of which is condensed in the indoor heat exchanger 3 to heat the room, and expanded through the capillary tube 19IF- to the second The other one enters the heat exchanger 12 and evaporates, and the other one passes through the flow rate adjustment capillary tube 20 of the branch flow path 15 to the second
After passing through the electromagnetic valve 17 and defrosting in the first heat exchanger 11, it joins and returns to the compressor IK via the accumulator 6.

The air temperature distribution on the outdoor heat exchanger during defrosting according to the embodiment of FIG. Although the temperature has risen due to frost, the second heat exchanger 12 continues its heating operation and is being cooled. The operations and functions of each component in the above-mentioned operating state are shown in FIG. 6. Note that a detailed explanation regarding FIG. 6 will be given later in the explanation of other embodiments.

In the air-cooled heat pump type air conditioner shown in Figure 1, comparatively,
By using part of the circulating refrigerant for defrosting in the operating range at high outside temperatures, heating operation can be continued without interruption, improving comfort and
As an air conditioner dedicated to heating, it does not require a four-way valve or check valve, which is found in conventional reverse cycle defrosting systems.

A simple refrigeration cycle can be constructed, resulting in lower costs and improved reliability.

Next, regarding other embodiments of the present invention, FIGS. 2, 4,
This will be explained with reference to FIGS. 5, 6, 7, 9, and 10.

Here, FIG. 2 is a refrigeration cycle system diagram of an air-cooled heat pump type air conditioner according to another embodiment of the present invention, and FIG.
A schematic circuit diagram of the control circuit in each embodiment, FIG. 9 is a cycle explanatory diagram during cooling operation of the refrigeration cycle of FIG. 2, and FIG. 10 is an outside air temperature explaining the operating state during operation of FIG. 9. - It is a discharge pressure diagram.

The embodiment shown in FIG. 2 is an example of an air-cooled heat pump type air conditioner for both cooling and heating, and is suitable for a unit VC with a wide operating range. In the figure, parts with the same numbers as in Fig. 3 are equivalent to the prior art, and parts with the same numbers as in Fig. 1 are as follows.
Since these parts are equivalent to those of the embodiment shown in FIG. 1, their explanation will be omitted.

In FIG. 2, 21ri is a check valve provided in parallel to the capillary tube 18 of the flow path 13, and 22 is a reverse valve provided in parallel to the capillary tube 19 of the flow path 14. The configuration is equivalent to the prior art shown in FIG. 3 or the embodiment shown in FIG.

The configuration of the outdoor heat exchanger of this embodiment is as shown in FIG. 4, and includes a first thermistor 31 and a second thermistor 32 for sensing refrigerant evaporation temperature or pipe surface temperature for defrosting operation control.
are the vibrator 11b of the first heat exchanger 11 and the second vibrator, respectively.
It is attached to the pipe 12b of the heat exchanger 12.

Figure 5 shows the circuit configuration of the defrosting operation control.
is the A coil/I/(SvA) of the first solenoid valve, 27 is the B coil (SvB) of the second solenoid valve, 28 is the outdoor fan motor contactor (CF), 29f'i is the four-way valve coil (Rv), 30d7'! 7/ shows the board.

The printed circuit board 30 receives input signals from the first thermistor 31 and the second thermistor 32, and the A coil 26 of the first solenoid valve connected to the printed circuit board 30, the B coil 27 of the second solenoid valve, and the outdoor A fan motor contactor 28 and a four-way valve coil 29 are controlled.

Next, the operation of the refrigeration cycle having such a configuration will be explained.

, during heating operation Vc, the refrigerant flows in the direction of the solid arrow.

Refrigerant gas discharged from the compressor 1 passes through a four-way valve 2 and is condensed in an indoor heat exchanger 3 to heat the room. The condensed refrigerant is
Pass through the reverse valve 7 and connect the flow path 13.14 on the outdoor heat exchanger inlet side.
One part passes through the first electromagnetic valve 16 and is expanded by the capillary tube 18, enters the first heat exchanger 11VC and evaporates, and the other part expands by the capillary tube 19 and enters the second heat exchanger 12. It evaporates when it enters.

The evaporated refrigerant gas returns to the compressor 1 via the four-way valve 2 and the achievator 6, forming a cycle.

At this time, the second solenoid valve 17 is closed.

Next, during hobto gas defrosting operation while heating,
The refrigerant flows in the direction of the dash-dot arrow.

Of the refrigerant gas discharged from the compressor 1, the refrigerant gas that performs the heating action flows in the same manner as during heating operation, performs indoor heating in the indoor heat exchanger 3, condenses, and passes through the flow path 14 and the capillary tube 19. It is evaporated in the second heat exchanger 12. The refrigerant gas that performs the defrosting action flows from the compressor discharge gas flow path to the branch flow path 15.
After passing through the flow rate adjusting capillary tube 20 and the second electromagnetic valve 17, the air enters the first heat exchanger 11Vc for defrosting.

At this time, the first solenoid valve 16 is closed.

The refrigerant gas that joins the first heat exchanger 11 and the second heat exchanger 12 on the outlet side flows in the same manner as during heating operation and is concentrated in the compressor 1.

Furthermore, during reverse cycle defrosting, such as when outside air conditions are severe and a large amount of defrosting capacity is required, the refrigerant flows in the direction of the dashed arrow. Note that the cycle indicated by the dashed arrow is the same during cooling operation.

The refrigerant gas discharged from the compressor 1 passes through the four-way valve 2 and then into the first
The refrigerant enters the heat exchanger 11 and the second heat exchanger +21C, performs defrosting, and condenses itself. The condensed refrigerant passes through the reversal valve 21 and the first electromagnetic valve 16 on one side, and the other side passes through the check valve 22 and joins together, and then expands in the cavity chamber 9.
It evaporates in the indoor heat exchanger 3. The evaporated refrigerant gas returns to the compressor 1 via the four-way valve 2 and the accumulator 6, forming a cycle. At this time, the second solenoid valve 17 is closed.

FIG. 6 is a drawing showing the operation of each functional component in the above-mentioned operation control, and the operation will be explained in correspondence with FIG. 2.4.

1st. When the temperature of the thermistor section detected by the second thermistor 31, 32 is higher than the set value, the first solenoid valve 16
is open, the second solenoid valve 17 is closed, and the outdoor fan 5
is rotated, the four-way valve 2 is in the heating position, and the first one of the outdoor heat exchanger is turned on. The second heat exchangers 11 and 12 also act as evaporators and perform heating operation.

Next, the first heat exchanger ++Vc is frosted, and the first thermistor 3
When the temperature of part 1 falls below the set value and the hop gas defrost control is activated by the input signal, the first solenoid valve 1
6 is closed, the second solenoid valve 17 is open, and the first heat exchanger 1
1 is a hot gas defrost, the second heat exchanger 12 is an evaporator,
In other words, heating operation continues. At this time, the outdoor fan 5 is rotating and the two four-way valves are in the heating position.

Furthermore, when outside air conditions are severe, or when the operation time is long υ, frost has formed on the second heat exchanger 12, and reverse cycle defrost control is activated by the second thermistor 320 input signal υ. The first electromagnetic valve 16 is opened, the second electromagnetic valve 17t/'i is closed, the outdoor fan 5 is stopped, the four-way valve 2 is in the unmasking position, and the first electromagnetic valve 17t/'i is closed. The second heat exchangers 11 and 12 are also defrosted.

The air temperature changes shown in FIGS. 7 and 8 are the same as in the embodiment shown in FIG. 1 above during heating operation and hopt gas defrosting operation, and during reverse cycle removal operation shown in FIG.
The first part of the outdoor heat exchanger. The temperature distribution on the second heat exchanger 11 and 12 is as shown in the diagram (reverse cycle defrosting) in Figure 7.
As shown in FIG. 0, by controlling the opening and closing of the first solenoid valve 16, the capacity of the outdoor heat exchanger can be adjusted and the range of cooling operation at low outside temperatures can be expanded.

In other words, in conventional cooling operation, the outside temperature varies from T to T.
. As is clear from Fig. 10, when the discharge pressure decreases to P
As the cycle temperature decreases from 1 to P2, the cycle temperature also decreases as shown by the broken line, and there are problems such as the return of refrigerant to the compressor 1, so the lower limit of operation was the outside air temperature T0.

In the embodiment shown in FIG. 2, the first solenoid valve 16 is closed and the flow of refrigerant to the first heat exchanger 11 is closed, so that only the second heat exchanger 12 is used as the outdoor heat exchanger that acts as a condenser. As a result, the outside air temperature becomes T as shown by the solid line in FIG. Even if the temperature exceeds P2 and drops to T2, the discharge pressure can be maintained at P2 and the lower limit of cooling operation can be expanded to the outside temperature T2.

According to this embodiment, when the outside temperature is relatively high or during heating operation for a short time, there is no need to stop heating operation for defrosting, and heating operation can be continued, so there is no need to blow cold air into the room. This has the effect of improving comfort and cumulative heating capacity.

Further, even in low outside temperatures and heating operation for a long time, the defrosting operation using the reverse cycle defrosting method prevents incomplete defrosting, making it possible to provide a functionally superior unit.

In this way, from a cost perspective, it is possible to configure a cycle without using particularly expensive functional parts, and it is possible to improve functionality in many ways, which is effective in improving product quality. .

Although each of the above-mentioned embodiments describes an example of an air conditioner, the present invention is not limited to air conditioners, but can be applied generally to air-cooled heat pump type refrigeration cycle devices to the extent that similar effects are expected. This applies to

〔Effect of the invention〕

As described above, according to the present invention, there are functions that enable a cycle that suppresses frost formation during heating, a cycle that continues heating operation even during defrosting, and a tickle that expands the range of cooling operation at low outside temperatures. Therefore, it is possible to provide an air-cooled heat pump type refrigeration cycle device that is excellent in terms of performance.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle system diagram of an air conditioner according to one embodiment of the present invention, FIG. 2 is a refrigeration cycle system diagram of an air-cooled heat pump type air conditioner according to another embodiment of the present invention, and FIG. The figure is a refrigeration cycle system diagram of a conventional air-cooled heat pump type air conditioner, Figure 4 is a detailed configuration diagram of the outdoor heat exchanger section in each embodiment of Figures 1 and 2, and Figure 5 is a diagram of each implementation. A schematic circuit diagram of the control circuit in the example, FIG. 6 is an explanatory diagram of functional parts operation of each embodiment, FIG. 7 is an explanatory diagram of air temperature distribution in the outdoor heat exchanger section of each embodiment, and FIG. Fig. 7 is an psychrometric diagram showing changes in air conditions, Fig. 9 is a cycle explanatory diagram of the refrigeration cycle shown in Fig. 2 during cooling operation, and Fig. 10 is an explanation of the operating state during operation of Fig. 9. It is an outside temperature - discharge pressure diagram. 1...Compressor 3...Indoor heat exchanger 11...
・First heat exchanger 12...Second heat exchanger 13,
14... Channel 15... Branch channel 16...
First solenoid valve 17...Second solenoid valve 9,18
．． 19... Capillary tube 20... Flow rate adjustment capillary tube. 5th melon 77th size 1st time 1st seat 2nd group knee = Ji rod picture prostitute 蓼tom → tassel -11÷

Claims (1)

[Claims] In an air-cooled heat pump type refrigeration cycle device comprising at least a compressor, an outdoor heat exchanger, an indoor heat exchanger, an expander, and a refrigerant flow path connecting these devices, the outdoor heat exchanger is placed on the upstream side with respect to the air flow. A flow path for dividing the refrigerant is connected to each heat exchanger, and a first electromagnetic conductor is connected to the flow path that becomes the refrigerant inlet side during heating of the upstream heat exchanger. In addition to providing a valve, a branch flow path is provided that connects the compressor discharge gas flow path to the downstream side of the first electromagnetic valve of the flow path that becomes the refrigerant inlet side during heating of the upstream heat exchanger. An air-cooled heat pump type refrigeration cycle device characterized in that a second solenoid valve is provided in a branch flow path.