JPH1082566A - Air cooled packager-conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve annual operating efficiency by performance of energy conservation with a simple constitution by adding a refrigerant pump and bypass forming tube and a switching valve to a vapor compression type cooling circuit, and selectively executing any of operations of a compression cycle and heat transporting cycle. SOLUTION: A refrigerant pump 23 is provided at a tube between a condenser 22 and a thermal expansion valve 13 of a vapor compression type cooling circuit. When a sensed temperature of an atmospheric temperature sensor 31 becomes a predetermined value or higher, a compressor 21 is operated, a switching valve 24 is closed, a switching valve 25 is opened, and cooling operation of a compression cycle is conducted. The pump 23 is not operated. Meanwhile, when the sensed temperature of the sensor 31 becomes the predetermined value or lower, the pump 23 is operated, the valve 24 is opened, the valve 25 is closed, and the cooling operation of the transporting cycle; is executed. The compressor 21 is not operated. Thus, any of the cooling operations of the compression cycle and the transporting cycle is selectively executed according to the atmospheric temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air-cooling package air conditioner of an annual cooling type.

[0002]

2. Description of the Related Art In a communication room or a computer room, the amount of heat generated in the room is large, and it is necessary to perform annual cooling. A method disclosed in Japanese Patent Application No. 63-204450 is a method for increasing the so-called COP, which is the annual operating efficiency of an annual cooling type air conditioner. In this example, when the outside air temperature is low, the suction power of the compressor is made as small as possible, so that the operation in which the compression power is reduced as compared with when the outside air temperature is high is possible.
The relationship between the outside air temperature of this air conditioner and COP is shown in FIG.
FIG. 6 shows a refrigeration cycle drawn on the h diagram.

Further, in order to reduce the driving power when the outside air temperature is low, a refrigerant natural circulation cycle is prepared separately from the compression cycle, and both cycles are stored in the same package.
In addition, there is an air-cooled package air conditioner provided with a blower for both cycles. This example is shown in FIG.

That is, a double floor 42 is placed on a foundation floor 41.
And an indoor unit (evaporator) 50 is installed on the double floor 42. Also, indoors, an indoor unit (evaporator) 5
The outdoor unit (condenser) 60 is installed at a position higher than the zero installation position.

The indoor unit 50 includes a compressor 51, heat exchange coils 52 and 53, a blower 54, and an expansion valve 55, and creates cooling air by circulating a refrigerant between the outdoor unit 60 and the cooling air. As shown by arrows, the air is supplied to various devices (not shown) through the space in the double floor 42.

[0006] The outdoor unit 60 includes heat exchange coils 61 and 62 and a blower 63. The heat exchange coil 61 is connected to the compressor 51 of the indoor unit 50, the heat exchange coil 52, and the expansion valve 55 via the refrigerant pipes 43 for the compression cycle. The heat exchange coil 62 is connected to the indoor unit 5 via the refrigerant pipes 44 and 44 and the two-way valve 45 for the refrigerant natural circulation cycle.
0 is connected to the heat exchange coil 53.

[0007] The refrigerant natural circulation cycle is a system in which a condenser is provided at a higher position than an evaporator and heat can be transferred without power by utilizing a difference in specific gravity of the refrigerant. The cooling operation can be performed without heat transfer power by using the heat pump.

[0008] Some water-cooled package air conditioners have a so-called free cooling function of directly cooling the room with water cooled by a cooling tower when the outside air temperature is low. This example is shown in FIG.

That is, the air conditioning unit 70 is installed on a double floor. The air conditioning unit 70 includes a compressor 71, a condenser 7
2, an evaporator 73, a free-cooling heat exchanger 74, and a blower 75 are provided. The compressor 71, the condenser 72, and the evaporator 73 are sequentially connected by a refrigerant pipe (not shown) for a compression cycle. The condenser 72 and the free-cooling heat exchanger 74 are connected to a rooftop cooling tower (not shown) by cooling water circulation water pipes 76, 76. Cooling air is created by the air conditioning unit 70 and is supplied to various devices (not shown) through the space in the double floor.

[0010]

In the case of a packaged air conditioner in which the suction / discharge pressure ratio of the compressor is made as small as possible, even if the compressor is operated at a low compressor ratio, the cooling COP is reduced.
Is at most 10 or less, and the point that the outside air temperature is lower than the room temperature cannot be used sufficiently effectively.

In a device incorporating a natural refrigerant circulation cycle, (a) the configuration of the device is complicated, (b) four refrigerant pipes are required between the room and the outdoor, and construction costs are high. (C) Indoor and outdoor units There are problems such as restrictions on the installation conditions (height position) of the machine, and (d) an increase in fan power due to double heat exchange coils on the indoor side and the outdoor side.

[0012] The free cooling system employed in the water-cooled package air conditioner also has the advantage that the power of the blower is increased by doubling the exchanger as in the case of incorporating the refrigerant natural circulation cycle, and that the water quality of the cooling water is controlled. Is required.

The present invention has been made in view of the above circumstances.
The air-cooled package air conditioner of the first invention has a simple configuration,
With less refrigerant piping, energy-saving operation is possible without any restrictions on the installation conditions (height position) of indoor / outdoor units and without problems such as an increase in fan power and water quality management, thereby improving annual operation efficiency. The purpose is to achieve.

The air-cooled packaged air conditioner of the second invention has a simple structure, requires few refrigerant pipes, is not restricted by the installation conditions (height position) of the indoor and outdoor units, and increases the power of the blower and manages water quality. It is an object of the present invention to improve the annual operation efficiency by enabling energy-saving operation while ensuring a necessary and sufficient cooling capacity throughout the year while taking into consideration the outside air temperature without causing problems such as the above.

The air-cooled packaged air conditioner according to the third invention, in addition to the object of the second invention, is capable of performing a stable operation by preventing frequent repetition of a cooling operation in a compression cycle and a cooling operation in a heat transport cycle. With the goal.

[0016]

According to a first aspect of the present invention, there is provided an air-cooled package air conditioner comprising: a vapor compression type cooling circuit for circulating a refrigerant by connecting a compressor, a condenser, an expansion valve, and an evaporator with piping; A condenser-side blower that sends air to the evaporator, an evaporator-side blower that sends air to the evaporator, a refrigerant pump provided in a pipe between the condenser and the expansion valve, and connected in parallel with the compressor. A first pipe for refrigerant bypass, a first on-off valve provided on the first pipe, a second pipe for refrigerant bypass connected in parallel with the refrigerant pump, and a second pipe for refrigerant bypass. A second opening / closing valve, control means for operating the compressor, stopping the refrigerant pump, closing the first opening / closing valve, opening the second opening / closing valve, and executing a compression cycle operation;
Control means for stopping the compressor, operating the refrigerant pump, opening the first on-off valve, closing the second on-off valve, and executing a heat transport cycle operation.

An air-cooled package air conditioner according to a second aspect of the present invention is a vapor compression type cooling circuit for circulating a refrigerant by connecting a compressor, a condenser, an expansion valve, and an evaporator with a pipe, and a condenser for sending air to the condenser. A side blower, an evaporator-side blower that sends air to the evaporator, a refrigerant pump provided in a pipe between the condenser and an expansion valve, and a second refrigerant bypass connected in parallel with the compressor. 1 pipe, a first on-off valve provided on the first pipe, a second pipe for refrigerant bypass connected in parallel with the refrigerant pump, a second on-off valve provided on the second pipe, A temperature detecting means for detecting an outside air temperature, and when the detected temperature of the temperature detecting means is equal to or higher than a predetermined value, the compressor is operated to stop the refrigerant pump and close the first on-off valve to close the second on-off valve. Control means for opening the valve and performing the cooling operation of the compression cycle; When the temperature detected by the temperature detecting means is equal to or lower than a predetermined value, the compressor is stopped, the refrigerant pump is operated, the first open / close valve is opened, and the second open / close valve is closed, and the cooling operation of the heat transport cycle is performed. Control means for executing
Is provided.

An air-cooled package air conditioner according to a third aspect of the present invention is a vapor compression type cooling circuit for connecting a compressor, a condenser, an expansion valve, and an evaporator with piping to circulate a refrigerant, and a condenser for sending air to the condenser. A side blower, an evaporator-side blower that sends air to the evaporator, a refrigerant pump provided in a pipe between the condenser and an expansion valve, and a second refrigerant bypass connected in parallel with the compressor. 1 pipe, a first on-off valve provided on the first pipe, a second pipe for refrigerant bypass connected in parallel with the refrigerant pump, a second on-off valve provided on the second pipe, A temperature detecting means for detecting an outside air temperature, and when the temperature detected by the temperature detecting means becomes equal to or higher than a first predetermined value, the compressor is operated to stop the refrigerant pump and close the first on-off valve to close the first on-off valve. 2 Control to open the on-off valve and execute the cooling operation of the compression cycle And when the temperature detected by the temperature detecting means is equal to or lower than a second predetermined value (<first predetermined value), the compressor is stopped, the refrigerant pump is operated, and the first on-off valve is opened to open the first opening / closing valve. Control means for closing the two on-off valves and executing the cooling operation of the heat transport cycle.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a double floor 2 is provided on a base floor 1, and an indoor unit 10 is installed on the double floor 2.

The double floor 2 has a structure in which an upper floor is provided on the base floor 1 via a large number of support legs, and the upper floor is formed by an array of a large number of panels. These panels can be freely attached and detached as necessary at the time of maintenance and inspection. For this reason, the upper floor is generally called a free access floor.

The double floor 2 copes with generation of heat during operation of various devices (not shown) such as a communication device and a computer on the floor, and provides free access to cooling air sent from the indoor unit 10. It is also used as an air conditioner that supplies various devices through the space under the floor. For use as an air conditioner, a ventilation opening is formed in a necessary portion of the panels forming the free access floor.

The indoor unit 10 constitutes an annual cooling type air-cooled package air conditioner together with the outdoor unit 20. The indoor unit 10 is connected to the outdoor unit 20 via two refrigerant pipes 3 and 3, and has an evaporator 11, Evaporator side blower 12 and expansion valve 1
3 is provided.

The outdoor unit 20 includes a compressor 21, a condenser 22,
Refrigerant pump 23, first pipe 4 for refrigerant bypass, second pipe 5 for refrigerant bypass, first on-off valve 24, second on-off valve 2
5, and a condenser-side blower 26, which is installed outdoors.

The discharge port of the compressor 21 is provided with a condenser 22.
Is connected to a pipe, and the other end of the condenser 22 is connected to a suction port of the refrigerant pump 23 by a pipe. One end of the expansion valve 13 is connected to a discharge port of the refrigerant pump 23 via the refrigerant pipe 3,
The other end of the expansion valve 13 is connected to one end of the evaporator 11. The other end of the evaporator 11 is connected to the suction port of the compressor 21 via another refrigerant pipe 3.

Of these pipe connections, except for the refrigerant pump 23, the compressor 21, the condenser 22, the expansion valve 13, and the evaporator 11
The piping connection forms a vapor compression type cooling circuit. The condenser 22 and the expansion valve 13 of this vapor compression type cooling circuit
And a refrigerant pump 23 is provided for the pipe between them.

A first pipe 4 for refrigerant bypass is connected in parallel with the compressor 21, and the pipe 4 is provided with a first on-off valve 24. A second pipe 5 for refrigerant bypass is connected in parallel with the refrigerant pump 23, and the pipe 5 is provided with a second on-off valve 25.

The evaporator-side blower 12 sucks air in the indoor space above the double floor 2 and supplies the sucked air to the floor space below the double floor 2 through the evaporator 11. When the air in the indoor space passes through the evaporator 11, the refrigerant in the evaporator 11 loses heat and is cooled, and is supplied to the floor space as cooling air for various devices.

The condenser-side blower 26 sucks outdoor air and supplies the sucked air to the condenser 22. When the outdoor air passes through the condenser 22, the refrigerant in the condenser 22 loses heat to the outdoor air and condenses.

On the other hand, a control device 30 is provided in the outdoor unit 20. The control device 30 controls the entire air-cooled package air conditioner. The control device 30 includes an outside air temperature sensor 31 as temperature detecting means for detecting the outside air temperature, and further includes the following control means.

(1) When the temperature detected by the outside air temperature sensor 31 becomes equal to or higher than a first predetermined value, for example, about 12 ° C., the compressor 21 is operated to stop the refrigerant pump 23 and close the first opening / closing valve 24 to close the second opening / closing valve 24. Control means for opening the on-off valve 25 and executing the cooling operation of the compression cycle.

(2) When the detected temperature of the outside air temperature sensor 31 falls below a second predetermined value (<first predetermined value), for example, about 7 ° C. or less, the compressor 21 is stopped, the refrigerant pump 23 is operated, and the first opening / closing is performed. Control means for opening the valve 24, closing the second on-off valve 25, and executing the cooling operation of the heat transport cycle;

Next, the operation of the above configuration will be described. When the temperature detected by the outside air temperature sensor 31 becomes a predetermined value, for example, about 12 ° C. or more, the compressor 21 is operated, the on-off valve 24 is closed and the on-off valve 25 is opened, and the cooling operation of the compression cycle is performed. The refrigerant pump 23 is not operated.

In this case, the low-pressure gas refrigerant (steam) is compressed to a high temperature and high pressure by the compressor 21, and the high-temperature and high pressure gas refrigerant is sent to the condenser 22. The gas refrigerant sent to the condenser 22 is cooled by exchanging heat with the outside air to become a high-pressure liquid refrigerant. This liquid refrigerant passes through the pipe 5 and the on-off valve 25 and bypasses the refrigerant pump 23 to flow to the expansion valve 13, where it becomes a low-pressure two-phase refrigerant. The two-phase refrigerant flows to the evaporator 11, where it takes heat from indoor air to gasify it, and is led to the compressor 21 again.

By forming a compression cycle in this manner, cooling air is created and supplied to the space in the double bed 2. On the other hand, when the detected temperature of the outside air temperature sensor 31 becomes about 7 ° C. or less, the refrigerant pump 23 is operated, the on-off valve 24 is opened and the on-off valve 25 is closed, and the cooling operation of the heat transport cycle is performed. Compressor 21
Is not driven.

In this case, liquid refrigerant is sent from the refrigerant pump 23 and flows through the expansion valve 13 to the evaporator 11. The liquid refrigerant flowing into the evaporator 11 takes heat from the indoor air to become a gas refrigerant. The gas refrigerant passes through the pipe 4 and the on-off valve 24 to bypass the compressor 21 and flows to the condenser 22, where it is cooled and condensed by outside air, becomes a liquid refrigerant, and is again guided to the refrigerant pump 23. .

By forming the heat transport cycle in this manner, cooling air is created and supplied to the space in the double bed 2. FIG. 2 shows a compression cycle for performing cooling by operation of the compressor 21 on the ph diagram. FIG. 2 shows a heat transport cycle for performing cooling by operation of the refrigerant pump 23.
FIG. 3 is shown on the h diagram.

In the compression cycle, the condensing pressure is higher than the evaporating pressure, but in the heat transport cycle, the condensing pressure is lower than the evaporating pressure. In the compression cycle, if the outside air temperature increases, the condensing pressure may be increased according to the outside air temperature to perform the cooling operation, but in the heat transport cycle,
If the condensing pressure is not lower than the evaporating pressure, the cycle is not established, so that the cooling operation in the heat transport cycle becomes possible at the outside air temperature at which the refrigerant can condense at this condensing pressure.

That is, when the outside air temperature is high, cooling in the compression cycle is performed, and the outside air temperature is reduced, and from the point where the refrigeration cycle can be formed with a condensing pressure lower than the evaporation pressure, the cooling operation in the heat transport cycle is started. Can switch.

As described above, since either the cooling operation in the compression cycle or the cooling operation in the heat transfer cycle can be selectively executed, energy-saving operation can be performed, and the annual operation efficiency can be improved.

FIG. 4 shows the relationship between the outside air temperature and the operating efficiency (COP) in the case of actual annual cooling. As shown in the figure, the operating efficiency increases in the range where the outside air temperature is about 10 ° C. or less. In addition, since either the cooling operation in the compression cycle or the cooling operation in the heat transfer cycle is automatically selected and executed based on the outside air temperature, necessary and sufficient cooling capacity is secured throughout the year while taking the outside air temperature into consideration. can do.

In particular, the refrigerant pump 23 and the pipes 4 and 5 for forming the bypass, the on-off valve 24,
25, the configuration is simpler than that of the conventional apparatus shown in FIG. 7 incorporating a refrigerant natural circulation cycle, the number of refrigerant pipes is small, and the installation conditions (height position) of indoor and outdoor units are different. There are no restrictions.

The evaporator-side blower 12 has one evaporator 11
Only one condenser 22 is provided for the condenser-side blower 26.
Since only the heat exchange coils are supported, there is no problem that the power of the blower is increased due to the double arrangement of the heat exchange coils as in the conventional apparatus of FIG. 7 and the water-cooled package air conditioner of FIG.
Since the cooling water is not used unlike the water-cooled package air conditioner of FIG. 8, there is no problem of water quality management of the cooling water.

A first predetermined value is prepared for starting the compression cycle, and a second predetermined value is prepared for starting the heat transport cycle. The difference between the two predetermined values is provided. And the cooling operation of the heat transport cycle can be prevented from being frequently repeated, thereby enabling a stable operation. Operation stabilization leads to an increase in operation efficiency. The present invention is not limited to the above embodiment, and various modifications can be made without changing the gist.

[0044]

As described above, the air-cooled packaged air conditioner according to the first aspect of the present invention adds a refrigerant pump and a pipe for forming a bypass and an on-off valve to a vapor compression type cooling circuit, and operates the compression cycle and heat transport cycle. The operation is selectively performed in any of the above cases. Therefore, with a simple structure, with few refrigerant pipes, there is no restriction on the installation conditions (height position) of the indoor and outdoor units, and it is possible to increase the power of the blower. Energy-saving operation can be performed without problems such as water quality management, and annual operation efficiency can be improved.

The air-cooled package air conditioner according to the second aspect of the present invention adds a refrigerant pump and a pipe for forming a bypass and an on-off valve to a vapor compression type cooling circuit, and performs either cooling operation in a compression cycle or cooling operation in a heat transport cycle. Since the configuration is automatically selected and executed based on the outside air temperature, the configuration is simple, the number of refrigerant pipes is small, and the installation conditions (height position) of the indoor and outdoor units are not restricted. Without the problem of water quality management and the like, energy saving operation can be performed while ensuring necessary and sufficient cooling capacity throughout the year while considering the outside air temperature, and the annual operation efficiency can be improved.

An air-cooled package air conditioner according to a third invention is the air-cooled package air conditioner according to the second invention, wherein a first predetermined value for starting a cooling operation in a compression cycle is prepared and a second predetermined value for starting a cooling operation in a heat transport cycle is provided. Since two predetermined values (<first predetermined value) are prepared, stable operation is possible by preventing frequent repetition of cooling operation in the compression cycle and cooling operation in the heat transport cycle.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of one embodiment.

FIG. 2 is a diagram showing a compression cycle in the embodiment on a ph diagram.

FIG. 3 is a diagram showing a heat transport cycle in the same example on a ph diagram.

FIG. 4 is a diagram showing the relationship between the outside air temperature and the operating efficiency (COP) when the embodiment is actually cooled annually.

FIG. 5 is a diagram showing the relationship between the outside air temperature and the COP of a conventional air conditioner in which the suction-discharge pressure ratio of the compressor is made as small as possible.

FIG. 6 is a diagram showing, on a ph diagram, a refrigeration cycle of a conventional air conditioner in which the suction-discharge pressure ratio of the compressor is made as small as possible.

FIG. 7 is a diagram showing a configuration of a conventional air-cooled package air conditioner using a refrigerant natural circulation cycle.

FIG. 8 is a diagram showing a configuration of a conventional water-cooled package air conditioner.

[Explanation of symbols]

 2 ... Double bed 3, 3 ... Refrigerant pipe 4 ... First pipe 5 ... Second pipe 10 ... Indoor unit 11 ... Evaporator 12 ... Evaporator side blower 21 ... Compressor 22 ... Condenser 23 ... Refrigerant pump 24 ... No. 1 on-off valve 25 ... second on-off valve 30 ... control device 31 ... outside air temperature sensor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigenori Waratani 1-4-3, Roppongi, Minato-ku, Tokyo Inside NTT Facilities Co., Ltd. (72) Inventor Kazuo Chiba 1-4-4 Roppongi, Minato-ku, Tokyo No. 33 Inside NTT Facilities

Claims (3)

[Claims] 1. A vapor compression cooling circuit for connecting a compressor, a condenser, an expansion valve, and an evaporator with piping to circulate a refrigerant, a condenser-side blower for sending air to the condenser, and a wind for the evaporator. An evaporator-side blower, a refrigerant pump provided in a pipe between the condenser and an expansion valve, a first pipe for a refrigerant bypass connected in parallel with the compressor, and a first pipe. A first on-off valve provided, a second pipe for refrigerant bypass connected in parallel with the refrigerant pump, a second on-off valve provided on the second pipe, and the refrigerant operated by operating the compressor. Control means for stopping a pump and closing the first on-off valve and opening the second on-off valve to execute a compression cycle operation; stopping the compressor to operate the refrigerant pump and performing the first on-off operation Open the valve and close the second on-off valve to operate the heat transport cycle. An air-cooled package air conditioner, comprising: a control unit that executes. 2. A vapor compression cooling circuit for connecting a compressor, a condenser, an expansion valve, and an evaporator with piping to circulate refrigerant, a condenser-side blower for sending air to the condenser, and a wind for the evaporator. An evaporator-side blower, a refrigerant pump provided in a pipe between the condenser and an expansion valve, a first pipe for a refrigerant bypass connected in parallel with the compressor, and a first pipe. A first on-off valve provided, a second pipe for refrigerant bypass connected in parallel with the refrigerant pump, a second on-off valve provided on the second pipe, and a temperature detecting means for detecting an outside air temperature. When the temperature detected by the temperature detecting means is equal to or higher than a predetermined value, the compressor is operated to stop the refrigerant pump, and
Control means for closing the on-off valve and opening the second on-off valve to perform a cooling operation in a compression cycle; and when the temperature detected by the temperature detecting means is equal to or lower than a predetermined value, the compressor is stopped to stop the refrigerant pump. Driving and said first
Control means for opening the on-off valve, closing the second on-off valve, and executing the cooling operation of the heat transport cycle. 3. A vapor compression cooling circuit for circulating a refrigerant by connecting a compressor, a condenser, an expansion valve, and an evaporator with piping, a condenser-side blower for sending air to the condenser, and a wind for the evaporator. An evaporator-side blower, a refrigerant pump provided in a pipe between the condenser and an expansion valve, a first pipe for a refrigerant bypass connected in parallel with the compressor, and a first pipe. A first on-off valve provided, a second pipe for refrigerant bypass connected in parallel with the refrigerant pump, a second on-off valve provided on the second pipe, and a temperature detecting means for detecting an outside air temperature. When the temperature detected by the temperature detecting means is equal to or higher than a first predetermined value, the compressor is operated to stop the refrigerant pump, close the first opening / closing valve, open the second opening / closing valve, and start the compression cycle. Control means for executing a cooling operation; When the temperature becomes equal to or lower than a second predetermined value (<first predetermined value), the compressor is stopped, the refrigerant pump is operated, the first on-off valve is opened, and the second on-off valve is closed, and the heat transport cycle is stopped. An air-cooled package air conditioner, comprising: a control unit that executes the cooling operation of the air conditioner.