JP2002286317A - Vapor compression heat pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump capable of effectively preventing the adherence of frost or the adherence and accumulation of snow in a heat absorbing heat exchanger (evaporator) while a primary operation is continued in a stable way by maintaining a high heat pump efficiency. SOLUTION: In a vapor compression heat pump, a refrigerant R is circulated in regular order of a compressor 1, to a hear radiating heat exchanger 2, to an expansion mechanism 5, to the heat absorbing heat exchanger 3, to a compressor 1, and the heat absorbing heat exchanger 3 functioning as an evaporator in the circulation of the refrigerant performs a heat absorbing action to outside air OA. In the refrigerant circulation path, a super-cooling device 9 using the outside air as a cooling source is interposed between the heat radiating heat exchanger 2 and the expansion mechanism 5. The super-cooling device 9 is provided adjacently to the windward part 3A of the heat absorbing heat exchanger 3 in an outside air ventilation passage F.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor compression type heat pump for absorbing heat from outside air, and more particularly, to a compressor for compressing a refrigerant, a heat exchanger for heat radiation, an expansion mechanism, and a heat exchanger for heat absorption.
The present invention relates to a vapor compression heat pump that circulates in the order of a compressor and causes a heat-absorbing heat exchanger that functions as an evaporator to function as an evaporator in the refrigerant circulation to absorb heat to outside air.

[0002]

2. Description of the Related Art Conventionally, in a vapor compression type heat pump of this type, a heat absorbing heat exchanger in which heat is absorbed by the outside air as an evaporator, such as frost due to moisture in the outside air and deposition of snow in the outside air. When this occurs, the refrigerant circulation path is switched to a state in which the heat-absorbing heat exchanger functions as a condenser to melt the attached frost and attached snow with the heat generated by the condenser. Defrosting and snow removal operations such as melting attached frost and attached snow were performed by an additional electric heater.

[0003]

However, in the defrosting and snow removing operation of the system in which the refrigerant circulation path is switched to a state where the heat absorbing heat exchanger functions as a condenser (so-called hot gas system), the following (a) to (a). C) There was a problem.

(A) During the snow removal and defrosting operation, the original operation of absorbing heat from the outside air by the heat absorbing heat exchanger and generating heat by the heat radiating heat exchanger must be stopped. (B) In order to keep the original operation as long as possible, it is necessary to limit the frequency of the defrosting and snow removal operation, and to a certain extent the operation in a state in which the outside air ventilation is hindered by attached frost or attached snow. The operation is forcibly continued, which greatly reduces the heat pump efficiency. (C) During the snow removal and defrosting operation, a large amount of condensed liquid refrigerant accumulates in the heat-absorbing heat exchanger due to the cooling of the refrigerant due to the adhering frost and the adhering snow, so that the heat-absorbing heat exchanger functions as an evaporator. When the refrigerant circulation path is returned to the original state and the operation is returned from the defrosting and snow removing operation to the original operation, a so-called liquid back trouble in which the compressor sucks the liquid refrigerant is likely to occur.

[0005] On the other hand, in the defrosting and snow removing operation of the type in which the attached heater is melted by the electric heater, the above-mentioned (a) to
Although the problem as described in (c) can be avoided, there is a problem that the power consumption of the electric heater is large, the energy efficiency as a whole is low, and the operating cost is high.

In view of this situation, the main problems of the present invention are:
The problem is that the above-mentioned problem is effectively solved by a rational refrigerant circuit structure.

[0007]

Means for Solving the Problems [1] The invention according to claim 1 relates to a vapor compression heat pump, and the feature of the invention is that a refrigerant is compressed by a compressor, a heat exchanger for heat radiation, an expansion mechanism, a heat exchanger for heat absorption, In a configuration in which the heat absorbing heat exchanger functioning as an evaporator in the circulation of the compressor is made to absorb heat to outside air in the refrigerant circulation path, the heat radiating heat exchanger and the expansion mechanism are arranged in a refrigerant circuit. In this case, a supercooler using outside air as a cooling source is interposed, and this supercooler is located adjacent to the windward side of the heat-absorbing heat exchanger in the outside air ventilation path.

That is, since frost and snow deposits are concentrated on the windward side of the heat-absorbing heat exchanger in the direction of outside air flow, a supercooler (so-called “cooler”) is provided on the windward side of the heat-absorbing heat exchanger. According to the above-described configuration in which the subcooler is adjacent to the heat exchanger, the heat released from the supercooler reaching the heat exchanger for heat absorption (that is, the sensible heat taken from the condensed liquid refrigerant sent from the heat exchanger for heat dissipation as a condenser) is used. In addition, it is possible to effectively prevent frost and adhesion and deposition of snow in the heat exchanger for heat absorption.

Since the heat released from the supercooler is utilized in this way, the heat absorbing heat exchanger absorbs heat from the outside air and generates heat in the heat radiating heat exchanger without stopping the original operation. To prevent frost and snow from accumulating in the heat exchanger, and it is not necessary to forcibly continue operation in a state where the outside air is blocked by the adhering frost or snow. As a result, the original operation can be stably continued while maintaining a high heat pump efficiency even under an external air condition in which frost and snow are likely to adhere and accumulate.

In addition, since the heat exchanger for heat absorption functions as an evaporator and prevents the formation of frost and snow from adhering due to the heat released from the supercooler, the condensed liquid refrigerant absorbs heat by cooling the refrigerant due to frost and snow. The liquid back trouble as described above can be effectively avoided without accumulation in the heat exchanger.

Further, since an additional energy consuming device such as an electric heater is not required, the energy efficiency as a whole can be maintained at a high level, and an increase in operating cost can be avoided. As a result, it is expected that the heat pump capacity will be improved by supercooling (subcooling) the condensed refrigerant delivered from the heat exchanger for heat radiation.

By the way, in order to prevent frost and snow from adhering and depositing in the heat absorbing heat exchanger while continuing the original operation,
It is also conceivable to prevent frost and snow from accumulating and depositing by using part of the heat generated by the condenser (condensation latent heat of the refrigerant). There is a problem that the heat pump capacity is reduced substantially because it is consumed to prevent the adhesion and deposition of snow.In this regard, the heat released from the subcooler that uses outside air as a cooling source is used. The above configuration, which can be expected to improve, is more advantageous.

[2] The invention according to claim 2 specifies an embodiment suitable for carrying out the invention according to claim 1, and the feature thereof is that the subcooler and the heat-absorbing heat exchanger are characterized by the following features. Each is divided into a windward portion and a leeward portion, and in the outside air passage, the windward portion of the supercooler, the windward portion of the heat absorbing heat exchanger, the leeward portion of the supercooler, and the heat absorbing heat are provided. The point is that the leeward portion of the exchanger is adjacent to each other in a state of being arranged in that order from the leeward side.

In other words, according to this configuration, as described above, frost and snow deposits are concentrated on the windward portion of the heat-absorbing heat exchanger (particularly, the windward portion of the windward portion). Can be effectively prevented by the heat released from the windward portion of the supercooler adjacent to the windward portion of the heat exchanger for heat absorption from the windward side in the direction of outside air ventilation.

Further, depending on conditions such as when the size of the heat exchanger for adsorption in the outside air ventilation direction is large, melted water of frost and snow generated on the windward side of the heat exchanger for heat absorption is reduced by the outside air to the leeward side. May be re-freezing at the leeward side of the heat-absorbing heat exchanger, but in such a case, according to the above configuration, such re-freezing also occurs in the heat-absorbing heat exchanger. The supercooler located between the leeward and leeward parts can effectively prevent the heat released from the leeward part, and in this regard, frost and snow accumulate and accumulate in the heat exchanger for adsorption. The heat pump can be more excellent in protection against heat.

[3] The invention according to claim 3 specifies an embodiment suitable for carrying out the invention according to claim 1 or 2, and the feature thereof is that the transmission constituting the heat-absorbing heat exchanger is characterized. The point is that a large number of common heat transfer fins extending over the heat tubes and the heat transfer tubes constituting the supercooler are provided on these heat transfer tubes.

In other words, according to this configuration, the heat released from the supercooler can be efficiently and reliably transmitted to the heat-absorbing heat exchanger by the large number of common heat transfer fins. The prevention of frost and the prevention of snow adhesion as described above using the heat released from the cooler can be made more effective and reliable.

[4] The invention according to claim 4 is the invention according to claims 1 to
The present invention specifies a preferred embodiment for practicing the invention according to any one of (3) and (3), characterized in that the circulating refrigerant passes through the supercooler and the circulating refrigerant passes through a bypass for the subcooler. The point is that a switching valve for switching the circulation path of the refrigerant between the passage state and the passage state is provided.

In other words, according to this configuration, the state can be switched to a state in which the circulating refrigerant passes through the bypass passage for the subcooler (that is, a state in which the refrigerant is circulated by bypassing the subcooler), whereby the subcooling is performed. Heat pumps that can be used for operations that do not require a cooler or for which it is more advantageous not to use a supercooler, for example, in terms of reducing pressure loss, etc. become.

[0020]

1 shows a refrigerant circuit of a heat pump, 1 is a compressor, 2 is a heat exchanger for heat dissipation, 3 is a heat exchanger for heat absorption, 4 is a four-way valve, 5 is an expansion mechanism, and 6 is an expansion mechanism. A refrigerant guide circuit in which four check valves 6a to 6d are combined in a bridge circuit shape, and 7 is a liquid receiver. In this heat pump, the following forward operation and reverse operation are basically selectively performed by switching the refrigerant circulation path by the four-way valve 4.

That is, in the forward operation, the refrigerant R is supplied to the compressor 1, the four-way valve 4, the heat exchanger for heat radiation 2, the refrigerant guide circuit 6, the liquid receiver 7, and the expansion mechanism 5, as indicated by solid arrows in the drawing. -Refrigerant guide circuit 6-Heat exchanger for heat absorption 3-Four-way valve 4-Compressor 1
In this order, the heat absorbing heat exchanger 3 functions as an evaporator, causing the heat absorbing heat exchanger 3 to absorb heat from the fan 8 against the ventilated outside air OA. Function as a condenser to release heat exchanger 2
To generate high temperature heat.

In the reverse operation, as shown by a broken line arrow in the figure, the refrigerant R is supplied to the compressor 1, the four-way valve 4, the heat absorbing heat exchanger 3, the refrigerant guide circuit 6, the liquid receiver 7, and the expansion. Mechanism 5-refrigerant guide circuit 6-radiator heat exchanger 2-four-way valve 4-compressor 1
In this order, the heat-radiating heat exchanger 2 is caused to function as an evaporator, and the heat-radiating heat exchanger 2 is made to absorb heat on the object to which heat is applied in the forward operation. The heat exchanger 3 functions as a condenser to generate high-temperature heat in the heat exchanger 3 for heat absorption.

Reference numeral 9 denotes a heat radiating heat exchanger 2 in the refrigerant circuit.
The supercooler is interposed between the fluid and the expansion mechanism 5 (specifically, between the liquid receiver 7), and the supercooler 9 uses outside air OA as a cooling source.

Reference numeral 10 denotes a bypass for the subcooler 9, and reference numeral 11 denotes a state in which the circulating refrigerant R passes through the subcooler 9 in the forward operation and the reverse operation, respectively.
This is a switching valve that switches the circulation path of the refrigerant R between a state in which the circulation refrigerant R is passed through 0 (that is, a state in which the subcooler 9 is bypassed).

The heat-absorbing heat exchanger 3 and the subcooler 9 have a fin tube coil structure U as shown in FIG. 2, and the heat-absorbing heat exchanger 3 is a parallel heat transfer tube constituting the heat-absorbing heat exchanger 3. 3a (tubes) are meandered to form four rows of heat transfer tube rows 3A to 3D.
A to 3D are arranged side by side in the ventilation direction of the outside air OA, and the heat transfer fins 12 extending over the four heat transfer tube rows 3A to 3D are transferred to the heat transfer fins 12 with a large number of heat transfer tubes 3a penetrating therethrough. A large number of heat pipe arrays 3A to 3D are provided at a predetermined pitch.

As for the subcooler 9, the subcooler 9
Each of the parallel heat transfer tubes 9a (tubes) is meandered to form two heat transfer tube arrays 9A and 9B, and one of the two heat transfer tube arrays 9A and 9B is connected to a heat-absorbing heat exchanger. 3
Among the heat transfer tube rows 3A to 3D, the heat transfer tube row 3A of the heat exchanger 3 for heat absorption is arranged adjacent to the windward side of the heat transfer tube row 3A positioned at the most windward side in the outside air ventilation direction.
D, between the third row of heat transfer pipes 3C and the fourth row of heat transfer pipes 3D in the direction of outside air ventilation in the state adjacent to the two heat transfer pipe rows 3C and 3D. Are used as heat transfer fins common to the heat exchanger for heat absorption 3 and the supercooler 9, and the heat transfer tubes 9a forming the heat transfer tube arrays 9A and 9B of the supercooler 9 are used as the heat transfer tube arrays of the heat exchanger 3 for heat absorption. It has a structure penetrating through each heat transfer fin 12 together with the heat transfer tubes 3a forming 3A to 3D.

That is, regarding the heat exchanger 3 for absorbing heat,
By passing the refrigerant R through the heat transfer tubes 3a of each of the heat transfer tube rows 3A to 3D, the refrigerant R is evaporated by heat absorption from the outside air OA in the forward passage operation in the forward operation, and the refrigerant R in the backward passage operation in the reverse operation. The refrigerant R is condensed to generate heat. In the subcooler 9, the condensed liquid refrigerant R sent from the heat-radiating heat exchanger 2 as a condenser in the forward operation is caused to pass through the heat transfer tubes 9a of the heat transfer tube rows 9A and 9B, whereby The condensed liquid refrigerant R is cooled by the outside air OA during the passage in the pipe (supercooling by the outside air).

Then, the heat absorbing heat exchanger 3 and the supercooler 9
By adopting the fin tube coil structure U described above, the heat absorbing heat exchanger 3 and the subcooler 9 can be connected to the windward portions 3A to 3C and 9A and the leeward portions 3D and 9B, respectively.
And the windward portion 9A of the supercooler, the windward portions 3A to 3C of the heat absorbing heat exchanger 3, and the supercooler 9
Leeward portion 9B of the heat-absorbing heat exchanger 3
D are arranged in the outside air passage F by the fan 8 adjacent to each other in a state of being arranged from the windward side in that order.

That is, in the forward operation in which the heat-absorbing heat exchanger 3 acts as an evaporator to absorb heat to the outside air OA, the windward portions 3A to 3C of the heat-absorbing heat exchanger 3 depend on the outside air condition.
(Especially, the windward portion 3A among the windward portions 3A to 3C, there is a possibility that frost due to moisture in the outside air and adhesion and deposition of snow in the outside air may occur at the windward portion 3A.
Frosting and deposition of snow on the windward portion 3A of the heat absorbing heat exchanger 3 are prevented by the heat released from the windward portion 9A of the supercooler 9.

Depending on the conditions, the frost or snow melted by the heat released from the supercooler windward portion 9A may be melted by the outside air O.
In contrast to the possibility of re-freezing at the leeward portion 3D (or 3C, 3D) of the heat-absorbing heat exchanger 3 due to the movement to the leeward side by A, the supercooler 9 Of the leeward side portion 9B of the fin is reliably prevented.

In the forward operation, the switching valve 11 is kept in the closed state, and the liquid refrigerant R delivered from the heat radiating heat exchanger 2 is always supercooled by the supercooler 9 (in other words,
Only when it is necessary to prevent frost or snow adhesion based on the detection of the outside air condition or the detection of frost or snow adhesion based on the detection of the outside air condition or the detection of frost or snow adhesion. Any of the operation modes in which the switching valve 11 is closed and the subcooler 9 functions can be adopted.

The reverse operation is performed for the purpose of generating cold heat in the heat exchanger 2 for heat radiation or for heating the outside air in the heat exchanger 3 for heat absorption. In the heat exchanger 3 for heat absorption, frost and snow are prevented from adhering and accumulating, and temporarily implemented for the purpose of defrosting and removing snow when it is no longer possible. In the reverse operation, the switching valve 11 is opened. The operation is performed with the supercooler 9 stopped functioning.

[Another Embodiment] Next, another embodiment of the present invention will be listed.

In the above-described embodiment, the subcooler 9 is divided into the windward portion 9A and the leeward portion 9B, and the windward portion 9A of the supercooler 9 and the windward portion 3A of the heat exchanger 3 for heat absorption are divided. ~
3C, the leeward portion 9B of the supercooler 9 and the heat exchanger 3 for heat absorption.
The leeward portion 3D is arranged adjacent to each other in a state where the leeward portion 3D is arranged in this order from the windward side. Instead, the subcooler 9 is divided in the outside air ventilation path F without dividing the subcooler 9. A configuration may be adopted in which the heat absorption side heat exchanger 3 is adjacent to the windward side from the windward side (adjacent in some cases from the leeward side).

The leeward portion 9A of the subcooler 9, the leeward portions 3A to 3C of the heat absorbing heat exchanger 3, the leeward portion 9B of the supercooler 9, and the leeward portion 3D of the heat absorbing heat exchanger 3 are connected. When they are adjacent to each other in a state of being arranged from the windward side in that order, the capacity ratio of these portions (the ratio of the number of heat transfer tube rows in each portion in the aforementioned embodiment) is the capacity shown in the aforementioned embodiment. The ratio is not limited, and for each of the supercooler 9 and the heat-exchanging heat exchanger 3, the leeward portions 9A, 3A to 3C and the leeward portions 9B, 3D are located on the refrigerant path. It may be either parallel or serial.

In the outside air passage F, the windward portion 9A of the supercooler 9 and the windward portions 3A to 3C of the heat absorbing heat exchanger 3
When the leeward part 9B of the supercooler 9 and the leeward part 3D of the heat absorbing heat exchanger 3 are arranged adjacent to each other in this order from the windward side, or the subcooler 9 is not divided. When the supercooler 9 is made to be adjacent to the windward side of the heat exchanger 3 for heat absorption, the specific adjacent structure is not limited to the adjacent structure between the heat transfer tube rows as in the above-described embodiment, and various configurations are changed. Is also possible, and in the above embodiment,
A common heat transfer fin 1 is used for the supercooler 9 and the heat absorbing heat exchanger 3.
Although the structure in which the supercooler 9 and the heat-absorbing heat exchanger 3 are separated from each other may be used in some cases, the structure is shown in FIG.

The vapor compression heat pump according to the present invention comprises:
It can be used for various applications in various fields such as air conditioning, snow melting, hot water supply and article heating.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram.

FIG. 2 is a cutaway perspective view showing the structures of a heat exchanger for heat absorption and a subcooler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Heat exchanger for heat dissipation 3 Heat exchanger for heat absorption 3a Heat transfer tube 3A-3C Upwind part of heat exchanger for heat absorption 3D Downwind part of heat exchanger for heat absorption 5 Expansion mechanism 9 Subcooler 9a Heat transfer tube 9A Upwind part of subcooler 9B Downwind part of subcooler 10 Bypass path 11 Switching valve 12 Heat transfer fin OA Outside air R Refrigerant

Claims (4)

[Claims] 1. A refrigerant is circulated in the order of a compressor, a heat exchanger for heat dissipation, an expansion mechanism, a heat exchanger for heat absorption, and a compressor, and the heat exchanger for heat absorption, which functions as an evaporator in the circulation of the refrigerant, is supplied to the outside air. A steam compression heat pump for absorbing heat to the heat exchanger, wherein a supercooler that uses outside air as a cooling source is interposed between the heat radiating heat exchanger and the expansion mechanism in a refrigerant circulation path. A vapor compression heat pump which is adjacent to the windward side of the heat absorbing heat exchanger in the outside air ventilation passage. 2. The heat exchanger for heat absorption according to claim 1, wherein each of the subcooler and the heat exchanger for heat absorption is divided into a windward portion and a leeward portion. 2. The vapor compression heat pump according to claim 1, wherein a leeward portion of the heat exchanger, a leeward portion of the supercooler, and a leeward portion of the heat absorbing heat exchanger are adjacent to each other in that order from the leeward side. 3. The heat transfer tube according to claim 1, wherein a plurality of common heat transfer fins extending from the heat transfer tube forming the heat absorbing heat exchanger to the heat transfer tube forming the subcooler are provided.
A vapor compression heat pump as described. 4. A switching valve for switching a refrigerant circulation path between a state in which the circulating refrigerant passes through the subcooler and a state in which the circulating refrigerant passes through a bypass passage for the subcooler. The vapor compression heat pump according to any one of the above.