JPH0351673A - Heat pump type cooling or heating device - Google Patents

Abstract

PURPOSE:To simplify a piping work in a pressure reducing mechanism by a method wherein the first and second capillary tubes are connected in series, the first and second check valves are connected in parallel with the capillary tubes in an opposite direction and a solenoid valve is arranged in a bypassing pipe for use in connecting between the first and second capillary tubes and between the first and second check valves. CONSTITUTION:In case of heating operation, a solenoid valve 25 is released, gaseous refrigerant of high pressure discharged from a compressor 1 is liquified with an indoor heat exchanger 3 through a four-way valve 2 and flowed to a pressure reducing mechanism 4. At this pressure reducing mechanism 4, the refrigerant passes from the first check valve 13 through a solenoid valve 25 and its pressure is reduced by the first capillary tube 21. The refrigerant of which pressure is reduced is gasified with an outdoor heat exchanger 5, the refrigerant passes through the four-way valve 2 and is returned to the compressor 1. At this time, the first capillary tube 21 is adjusted in such a way as a flow rate of the refrigerant becomes the most suitable value. Then, in case of a low operating frequency, the solenoid valve 23 is closed to flow the refrigerant from the second capillary tube 22 to the capillary tube 21 and a sufficient pressure reduction is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an air conditioning system, and more particularly to a heat pump type air conditioning system that can control the amount of refrigerant circulated.

[Prior Art] Conventionally, it has been necessary to appropriately control the amount of refrigerant circulated in the refrigeration cycle of an air-conditioning device. However, when a capillary tube is used as a pressure reducing mechanism, the range of adjustment of the refrigerant flow rate is small, so that it may not be possible to properly control fluctuations in various conditions.

Therefore, as a solution to this problem, a heating and cooling device has been proposed that uses a solenoid valve to adjust the amount of restriction of the capillary tube.

For example, FIG. 2 is a system diagram showing the refrigerant piping of a conventional heat pump air-conditioning device disclosed in Japanese Utility Model Application Publication No. 195265/1983.

In the figure, (1) is a compressor that compresses the refrigerant, (2) is a four-way valve that switches the refrigerant circulation path, (3) is an outdoor heat exchanger installed indoors, and (4) is a compressor that reduces the pressure of the refrigerant. (5) is an outdoor heat exchanger installed outdoors, (6)
) is an accumulator that functions as a gas-liquid separator.

In this heat pump air conditioning system, a pressure reduction mechanism (4) is arranged between an indoor heat exchanger (3) and an outdoor heat exchanger (5), and a compressor (1), an indoor heat exchanger (3), a pressure reduction Mechanism (4)
, and an outdoor heat exchanger (5) are connected to form a refrigeration cycle.

Here, the pressure reduction mechanism (4
) will be explained below. (11) is the first main capillary tube, (12) is the second main capillary tube, and (13) is the first main capillary tube (1
(1) is a first check valve connected in series to the second main capillary tube, and (14) is a second check valve connected in series to the second main capillary tube, which form a bridge and control the pressure reducing mechanism (4). It constitutes the basic piping. (15) is the first solenoid valve, (
Reference numeral 16) denotes first auxiliary capillary tubes (16), which are connected in series and arranged in parallel to the first main capillary tube (11). (17) is a second electromagnetic valve, and (18) is a second auxiliary capillary tube, which are connected in series and arranged in parallel to the second main capillary tube (12).

In the figure, solid arrows indicate the flow direction of the refrigerant during the heating cycle, and dashed arrows indicate the flow direction of the refrigerant during the cooling cycle.

The heat pump air conditioning system configured as described above operates as follows.

First, I will explain heating operation. At the start of the heating cycle, the refrigerant compressed to high pressure by the compressor (1) is sent to the indoor heat exchanger (3) via the four-way valve (2).

This indoor heat exchanger (3) acts as a condenser, where the refrigerant is condensed and liquefied. At this time, the room is heated by dissipating heat into the room. Subsequently, the refrigerant flows into the pressure reducing mechanism (4). The pressure reducing mechanism (4) has a second check valve (
14) is in a closed state, the refrigerant flows through the first main capillary tube (11) and the first auxiliary capillary tube (16), passes through the first check valve (13), and enters the pressure reducing mechanism (4). ). After this, the refrigerant is vaporized in the outdoor heat exchanger (5) that acts as an evaporator, passes through the four-way valve (2), reaches the accumulator (6), and returns to the compressor (1) again, closing the refrigeration cycle. ing. However, after a certain amount of heating operation time has elapsed, the indoor air also warms up, and the temperature of the indoor heat exchanger (3) also rises, resulting in an excessive flow rate of refrigerant and liquid returning to the compressor (1). happens. Therefore, the first solenoid valve (15) is closed to prevent the refrigerant from flowing through the first auxiliary capillary tube (16).
Decreasing the flow rate of refrigerant.

On the other hand, during cooling operation, the refrigerant flows through the piping route opposite to the above. That is, the refrigerant compressed by the compressor (1) is
It is sent to an outdoor heat exchanger (5) via a four-way valve (2), where it is cooled by outside air and condensed.

Then, it is sent to the indoor heat exchanger (3) via the pressure reduction mechanism (4). In the indoor heat exchanger (3), the liquid refrigerant evaporates and cools the room by removing heat of vaporization from the room. The vaporized refrigerant passes through the four-way valve (2) to the accumulator (5).
Only the gaseous refrigerant is compressed again by the compressor (1). During this cooling operation, the second solenoid valve (17) is in the open state at the start of the operation, as described above. However, as the operating time passes and the indoor air is cooled and the temperature of the indoor heat exchanger (3) decreases, the flow rate of the refrigerant becomes excessive and liquid returns to the compressor (1).

Therefore, the second electromagnetic valve (17) is closed to prevent the refrigerant from flowing through the second auxiliary capillary tube (18), thereby reducing the flow rate of the refrigerant.

As mentioned above, in this type of conventional heat pump air conditioning system, the first solenoid valve (15) and the second solenoid valve (17)
) is opened and closed as appropriate depending on the operating conditions to adjust the flow rate of the refrigerant. This flow rate control maintains an appropriate indoor temperature during cooling or heating operation, and at the same time protects the compressor (1).

In addition to the above, a heat pump type air-conditioning device that adjusts the flow rate of refrigerant is disclosed in Japanese Patent Publication No. 6B-43660. This is to adjust the flow rate of refrigerant flowing through the pressure reducing mechanism during the heating cycle and during the cooling cycle.

Further, this type of pressure reducing mechanism (4) can also be used in a capacity control type refrigeration cycle that changes the frequency of the compressor (1). A capacity control type refrigeration cycle in which the frequency of the compressor (1) is changed is also disclosed in Japanese Patent Publication No. 6343660.

For example, during heating when the compressor (1) is operated at a high frequency, the first solenoid valve (15) is opened to adjust the flow rate of the refrigerant. However, in this state, the frequency is lowered and the compressor (1
), the pressure reduction becomes insufficient and liquid returns to the compressor (1). Therefore, when the frequency is low, the first solenoid valve (15) is closed to increase the pressure reduction.

In this way, the flow rate of the refrigerant is adjusted by appropriately opening and closing the first solenoid valve (15) and the second solenoid valve (17) according to the operating frequency of the compressor (1), similar to the conventional example described above. The indoor temperature can be properly maintained during cooling or heating operation, and the compressor (1) can be protected.

Furthermore, in addition to the above, a refrigerant control device for a heat pump type air-conditioning device is disclosed in Japanese Patent Laid-Open No. 140258/1983.

[Problems to be Solved by the Invention] However, in the conventional heat pump air conditioning system shown in FIG. It was composed of component parts. That is, four capillary tubes were used, and two check valves and two solenoid valves were required. For this reason, the piping configuration has become extremely complicated and the price has also increased.

Moreover, the unit volume of the pressure reducing mechanism (4) has increased, necessitating a large storage space. Therefore, it has been desired to provide a pressure reducing mechanism (4) with a simple configuration.

Although an air-conditioning device having a pressure reduction mechanism (4) with a simple configuration is also disclosed in JP-A-63-213764, this is related to defrosting, and it is necessary to reduce the pressure of the refrigerant depending on the operating state. The heating and cooling system was not adjustable.

Therefore, it is an object of the present invention to provide a heat pump type air-conditioning device that has a simple structure in which the pressure reduction mechanism has a small number of parts and can appropriately reduce the pressure of the refrigerant depending on the operating state.

[Means for Solving the Problems] A heat pump type air-conditioning device according to the present invention connects a first capillary tube (21) and a second capillary tube (22) in series, and connects a first capillary tube (22) in parallel with the first capillary tube (21). A check valve (13) and a second check valve (14) are connected in series and in opposite directions, and between the first capillary tube (21) and the second capillary tube (22) and the first a pressure reducing mechanism (4) in which a solenoid valve (23) is arranged in a bypass pipe connecting between the first check valve (13) and the second check valve (14);
The pressure reduction mechanism (4) is arranged between the indoor heat exchanger (3) and the outdoor heat exchanger (5), and the compressor (1) and the indoor heat exchanger (
3), a pressure reducing mechanism (4), and a refrigeration cycle formed by connecting an outdoor heat exchanger (5).

[Function] In the heat pump type air-conditioning device of the present invention, the pressure reduction mechanism (4) arranged between the indoor heat exchanger (3) and the outdoor heat exchanger (5) is connected to the first capillary tube (21). Connect in series with the second capillary tube (22),
In parallel with this, a first check valve (13) and a second check valve (1
4) in series and in opposite directions, and the first capillary tube (21) and the second capillary tube (22) are connected in series and in opposite directions.
) and between the first check valve (13) and the second check valve (14).
), the solenoid valve (23) is disposed in the bypass piping connecting between the pressure reducing mechanism (4), the piping configuration of the pressure reducing mechanism (4) is simplified, and the unit volume of the pressure reducing mechanism (4) can be reduced. Moreover, the pressure reduction mechanism (4) can adjust the pressure reduction of the refrigerant depending on the operating state.

[Embodiment] FIG. 1 is a system diagram showing refrigerant piping of a heat pump type air-conditioning device that is an embodiment of the present invention.

In the figure, (1) to (6) are the same or equivalent components of the conventional example. In the figure, solid line arrows indicate the flow direction of the refrigerant during the heating cycle, and broken line arrows indicate the flow direction of the refrigerant during the cooling cycle.

In the figure, (21) is the first capillary tube, (
22) is a second capillary tube, which are connected in series. In parallel with this, a first check valve (13) and a second check valve (14) are connected in series and in opposite directions.

(23) connects between the first capillary tube (21) and the second capillary tube (22) and between the first check valve (13) and the second check valve (14). This is a solenoid valve placed in the bypass piping.

In addition, in the heat pump type air-conditioning system of this example, as in the above-mentioned conventional example, a compressor (1), an indoor heat exchanger (3),
The pressure reduction mechanism (4) and the outdoor heat exchanger (5) are connected to form a refrigeration cycle.

Therefore, the basic circulation operation of the refrigerant during the cooling operation and the heating operation of the heat pump type air-conditioning device having this configuration is the same as in the conventional example.

Here, a case will be described in which the heat pump type air-conditioning device configured as described above is used in a capacity control type refrigeration cycle in which the frequency of the compressor (1) is changed. First, the heating operation in which the compressor (1) is operated at high frequency will be described. In this case, the solenoid valve (23) is in an open state. During this operating state, the high-pressure gaseous refrigerant discharged from the compressor (1) is liquefied in the indoor heat exchanger (3) via the four-way valve (2), and then transferred to the pressure reducing mechanism (4). Inflow. In this pressure reduction mechanism (4), the refrigerant passes through the first check valve (13), the electromagnetic valve (23), and is depressurized in the first capillary tube (21). This pressure reduction mechanism (4)
The refrigerant whose pressure is reduced is gasified in the outdoor heat exchanger (5) and returns to the compressor (1) via the four-way valve (2). Note that the first capillary tube (21) is adjusted so that the flow rate of the refrigerant is optimal at this high frequency. However, if the refrigeration cycle is shifted to a lower operating frequency, the flow rate of the refrigerant decreases, and the first capillary tube (21)
depressurization becomes insufficient. Therefore, the temperature of the outdoor heat exchanger (5), which is an evaporator, becomes higher than the flow rate of the refrigerant, and the liquid returns to the compressor (1) without being completely evaporated. Therefore,
When the operating frequency is low, the solenoid valve (23) is closed to allow the refrigerant to flow from the second capillary tube (22) to the first capillary tube (21) to achieve sufficient pressure reduction.

Next, we will discuss cooling operation. When the operating frequency is high, the solenoid valve (23) is opened in the same manner as above, and the refrigerant liquid flowing out from the outdoor heat exchanger (5) is passed through the second check valve (14), the solenoid valve (23), and the solenoid valve (23). 2 capillary tubes (
22). However, when the operating frequency is low, the solenoid valve (23) is closed and the refrigerant flows from the first capillary tube (21) to the second capillary tube (22) to achieve sufficient pressure reduction.

In this way, the heat pump type air-conditioning system of this embodiment prevents liquid from returning to the compressor (1), thereby protecting the compressor (1). In addition, the pressure reduction of the refrigerant is adjusted according to the operating frequency of the compressor (1) to appropriately maintain the indoor temperature during cooling or heating operation.

Further, in the pressure reducing mechanism (4) having this configuration, the flow direction of the refrigerant flowing through the solenoid valve (23) is the same during both cooling and heating. Therefore, when the solenoid valve (23) is in the closed state, the pressure relationship of the refrigerant before and after the solenoid valve (23) is approximately constant, and no trouble occurs beyond the opening/closing operation of the solenoid valve (23). As a result, the solenoid valve (23) performs the opening and closing operations in the path-to-road condition, so that the refrigerant flow rate adjustment is not affected by differences in the cooling or heating operating conditions.

As described above, in the heat pump type air conditioning system of this embodiment, the pressure reducing mechanism (4) arranged between the indoor heat exchanger (3) and the outdoor heat exchanger (5) is connected to the first capillary tube (21 ) and a second capillary tube (22) are connected in series, and in parallel with this, a first check valve (13) and a second check valve (14) are connected in series and in opposite directions, Said first
A solenoid valve (
23).

Therefore, the number of component parts of the pressure reducing mechanism (4) is reduced compared to the conventional example, the piping configuration is extremely simplified, and the unit volume of the pressure reducing mechanism (4) can be reduced, so the price of the entire device is reduced. Moreover, as in the conventional example, the pressure reduction of the refrigerant can be appropriately adjusted, and the compressor (1) can be protected and the indoor temperature can be maintained appropriately during cooling or heating operation.

By the way, in the above embodiment, the case where the heat pump air conditioning system is used in a capacity control type refrigeration cycle that changes the frequency of the compressor (1) was explained, but as described in the conventional example, during cooling and heating operation. Naturally, it can also be used to adjust the amount of refrigerant pressure reduction at startup and during stable operation.

As explained above, the heat pump air-conditioning device of the present invention connects the first capillary tube (21) and the second capillary tube (22) in series, and connects the first check valve (13) in parallel. ) and a second check valve (14) are connected in series and in opposite directions, and between the first capillary tube (21) and the second capillary tube (22) and the first check valve ( 13) and the second check valve (14), the pressure reducing mechanism (4) is configured by disposing a solenoid valve (23) in the bypass pipe connecting the indoor heat exchanger (3) during the refrigeration cycle.
By placing the pressure reduction mechanism (4) between the heat exchanger (5) and the outdoor heat exchanger (5), the piping configuration of the pressure reduction mechanism (4) can be simplified, and the unit volume of the pressure reduction mechanism (4) can be reduced, making the entire device cheaper. Become. Moreover, since the pressure reducing mechanism (4) can appropriately reduce the pressure of the refrigerant depending on the operating state, it is possible to protect the compressor (1) and maintain an appropriate indoor temperature during cooling or heating operation.

[Effect of the invention]

[Brief explanation of drawings]

FIG. 1 is a system diagram showing refrigerant piping of a heat pump type air conditioning system according to an embodiment of the present invention, and FIG. 2 is a system diagram showing refrigerant piping of a conventional heat pump type air conditioning system. In the figure, 1: Compressor 3: Indoor heat exchanger 4: Pressure reduction mechanism
5 Two outdoor heat exchangers 13: First check valve 14: Second check valve 21: First capillary tube 22: Second capillary tube 23: Solenoid valve. In the drawings, the same reference numerals and the same symbols indicate the same or equivalent parts.

Claims (1)

[Claims] A first capillary tube and a second capillary tube are connected in series, and a first check valve and a second check valve are connected in parallel in series and in opposite directions. , between the first capillary tube and the second capillary tube, and between the first capillary tube and the second capillary tube.
a pressure reducing mechanism in which a solenoid valve is disposed in a bypass pipe connecting between the check valve and the second check valve; and the pressure reducing mechanism is disposed between an indoor heat exchanger and an outdoor heat exchanger, and What is claimed is: 1. A heat pump type air-conditioning and heating system comprising: a heat exchanger, an indoor heat exchanger, a pressure reduction mechanism, and a refrigeration cycle formed by connecting an outdoor heat exchanger.