JPH06300318A - Radiation type cooling device - Google Patents

Abstract

PURPOSE:To provide a radiation type cooling device in which an indoor heat exchanger is organically connected to the radiation type heat exchanger and the heat exchanger can be excited stably when its operation is started. CONSTITUTION:A compressor 1, an outdoor heat exchanger 3, a first adjusting device 4, and an indoor heat exchanger 5 are connected in sequence. A series- connected circuit comprising a second adjusting device 6 and a first refrigerant- to-refrigerant heat exchanger 7 is connected in parallel with the first adjusting device 4 and the indoor heat exchanger 5 so as to constitute a first freezing cycle 8. Then, a refrigerant pump 10, a radiation type heat exchanger 14, a first refrigerant heat exchanger 7 and a liquid reservoir 11 are connected in sequence. The first refrigerant-to-refrigerant heat exchanger 7 is placed higher than the liquid reservoir 11 and the liquid reservoir 11 is placed higher than the refrigerant pump 10 so as to constitute a second freezing cycle 13. Refrigerant within the first freezing cycle 8 and the refrigerant in the second freezing cycle 13 can be indirectly heat exchanged by the first refrigerant-to-refrigerant heat exchanger 7. In addition, when the operation is started, the first freezing cycle 8 is operated and then the second freezing cycle 13 is operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device utilizing radiation.

[0002]

2. Description of the Related Art A radiant cooling device is conventionally known as a method for realizing a milder cooling. The conventional radiant cooling system has a piping pipe attached to the ceiling surface and allows cold water to flow inside it, or a refrigerant pipe is attached to act as an evaporator of a refrigeration cycle, so that the cold air in the room naturally falls. It is intended to realize air conditioning without a draft feeling. In addition, a dehumidifier was installed separately as a measure to prevent condensation on the ceiling.

[0003]

However, the problem with the conventional radiant cooling apparatus is that the circulation of cold water or refrigerant on the ceiling surface removes only the sensible heat of the indoor air.
The reason is that if the latent heat is taken away, dew will form on the ceiling. Therefore, the conventional radiant cooling device requires a separate cooling device for removing the latent heat of the indoor air, and the temperature control of the ceiling surface corresponding to the indoor humidity condition and the cooling load is complicated and large-scale. .

Further, in the case of using a refrigerant, it is difficult to maintain a shunt at the inlet of the evaporator and a stable refrigerant circulation amount when the refrigerant is fed into the evaporator in a two-phase state.
Further, if the refrigerant is sufficiently supercooled at the evaporator inlet, the current situation is that a uniform temperature distribution cannot be obtained near the evaporator inlet.

Further, there is no one that realizes a system capable of coping with radiant cooling and forced draft cooling organically, by one simple heat source device even at the start of operation or when the humidity rises suddenly. The points hindered the spread.

[0006] The present invention is to solve the problems of the conventional radiant cooling apparatus, and not only organically combine the radiant cooling apparatus using a refrigerant and the forced draft cooling apparatus for removing latent heat. Without, it starts stably even at the start of operation,
It is an object of the present invention to provide a radiant cooling device that does not cause dew condensation even when the humidity rises rapidly.

[0007]

A radiant cooling apparatus according to the present invention comprises a compressor, an outdoor heat exchanger, a first expansion device, and an indoor heat exchanger, which are connected in this order, and a second expansion device and a first refrigerant pair are connected in series. The refrigerant heat exchanger is connected to the first expansion device and the indoor heat exchanger in parallel to form a first refrigeration cycle,
Refrigerant pump, radiant heat exchanger, first refrigerant to refrigerant heat exchanger,
The first refrigeration cycle is configured by connecting the reservoirs and the like in order, arranging the first refrigerant-refrigerant heat exchanger higher than the reservoir, and arranging the reservoir higher than the refrigerant pump to form the second refrigeration cycle. The refrigerant circulating in the cycle and the refrigerant circulating in the second refrigeration cycle are indirectly heat-exchangeable by the first refrigerant-refrigerant heat exchanger.

Further, the radiant cooling apparatus of the present invention starts the compressor to operate the first refrigeration cycle at the start of operation, and then starts the refrigerant pump to operate the second refrigeration cycle.

Further, in the radiant cooling apparatus of the present invention, the radiant heat exchanger is provided with a radiant heat exchanger surface temperature measuring means and a dew point temperature measuring means in the vicinity thereof, and a second refrigerant pair is provided at an outlet of the refrigerant pump of the second refrigeration cycle. Refrigerant heat exchanger is connected to the first
By connecting a four-way valve and a second refrigerant-to-refrigerant heat exchanger between the compressor of the refrigeration cycle and the outdoor heat exchanger, and switching the four-way valve according to the dew point temperature, the refrigerant circulating in the first refrigeration cycle The configuration is such that the refrigerant circulating in the second refrigeration cycle can indirectly exchange heat with the second refrigerant-refrigerant heat exchanger.

[0010]

In the radiant cooling apparatus of the present invention, in the first refrigeration cycle, the outdoor heat exchanger functions as a condenser, the indoor heat exchanger, and the first refrigerant-refrigerant heat exchanger function as an evaporator. On the other hand, in the second refrigeration cycle, the first refrigerant-to-refrigerant heat exchanger acts as a condenser and the radiant heat exchanger acts as an evaporator. Here, by disposing the reservoir below the first refrigerant-refrigerant heat exchanger and further arranging the refrigerant pump below the reservoir, the refrigerant is not sufficiently supercooled in the first refrigerant-refrigerant heat exchanger. However, since it is easy to maintain the liquid state of the refrigerant at the refrigerant pump inlet / outlet, the refrigerant can be stably sent to the radiant heat exchanger, and at the same time, the degree of supercooling of the refrigerant at the radiant heat exchanger inlet can be reduced. A uniform temperature distribution can be obtained near the entrance of the radiant heat exchanger.

When the operation is started, the compressor is started to operate the first refrigeration cycle, and the refrigerant in the second refrigeration cycle is condensed by the first refrigerant-refrigerant heat exchanger to store the liquid refrigerant in the reservoir. After that, the refrigerant pump is started to operate the second refrigeration cycle to remove sensible heat and latent heat (moisture) of the indoor air in the indoor heat exchanger in advance, and at the same time, immediately after starting the refrigerant pump, the refrigerant is stably cooled. Can be supplied to the radiant heat exchanger, and the radiant heat exchanger temperature can be rapidly lowered.

Further, when the dew point temperature rises, such as when the window is opened, the four-way valve is switched, and the refrigerant of the second refrigeration cycle that has exited the refrigerant pump and the first refrigerant that has become hot due to being compressed by the compressor. By indirectly exchanging heat with the refrigerant in one refrigeration cycle in the second refrigerant-refrigerant heat exchanger, the temperature of the radiant heat exchanger can be increased and maintained at a dew point temperature or higher, and dew condensation can be prevented. . Therefore, it is possible to realize a mild cooling by removing the sensible heat of the indoor air in the radiant heat exchanger while removing the latent heat of the indoor air in the indoor heat exchanger. When the pipe is attached to the ceiling surface, the risk of dew condensation on the ceiling surface can be prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a radiant cooling apparatus according to the present invention, in which 1 is a compressor, 2 is a four-way valve, 3 is an outdoor heat exchanger, 4 is a first throttle device, and 5 is an indoor heat exchanger. , 6 is a second expansion device, 7 is a first refrigerant-to-refrigerant heat exchanger, and these devices are sequentially connected to form a first refrigeration cycle 8. The series portion of the second expansion device 6 and the first refrigerant-to-refrigerant heat exchanger 7 is connected in parallel to the series portion of the first expansion device 4 and the indoor heat exchanger 5. Further, by switching the four-way valve 2, the refrigerant discharged from the compressor 1 is connected directly to the outdoor heat exchanger 3 or to the outdoor heat exchanger 3 via the second refrigerant-refrigerant heat exchanger 9. There is.

Further, 10 is a refrigerant pump, 11 is a reservoir,
A radiant heat exchanger 12 is connected with the first refrigerant-refrigerant heat exchanger 7 and the second refrigerant-refrigerant heat exchanger 9 to form a second refrigeration cycle 13. Reference numeral 14 is a radiant heat exchanger surface temperature measuring means, and in the present embodiment, the radiant heat exchanger 12 is used.
Is measured and the surface temperature is obtained from the saturation temperature of the pressure. Reference numeral 15 is a dew point temperature measuring means near the radiant heat exchanger 12, which is a radiant heat exchanger surface temperature measuring means 1
4 is compared with the dew point temperature obtained from the dew point temperature measuring means 15, and the four-way valve 2 is connected so that the four-way valve 2 can be controlled via the control device 16 so that the surface temperature becomes higher.

In the first refrigerant-refrigerant heat exchanger 7, the refrigerant of the first refrigeration cycle 8 and the refrigerant of the second refrigeration cycle 13 are indirectly heat-exchanged. Further, in the second refrigerant-refrigerant heat exchanger 9, the refrigerant of the first refrigeration cycle 8 and the refrigerant of the second refrigeration cycle 13 are indirectly heat-exchanged by switching the four-way valve 2.

Next, the operation of the radiant cooling device will be described. First, a case where the four-way valve 2 is set so that the discharge side of the compressor 1 and the outdoor heat exchanger 3 are directly connected will be described.
In the first refrigeration cycle 8, the outdoor heat exchanger 3 functions as a condenser, and the indoor heat exchanger 5 and the first refrigerant-to-refrigerant heat exchanger 7 function as an evaporator. The high-temperature and high-pressure refrigerant discharged from the compressor 1 passes through the four-way valve 2 and exchanges heat with the outside air in the outdoor heat exchanger 3 to be cooled and condensed into liquid, and is reduced to a low pressure in the first expansion device 4 to be reduced to the indoor heat exchanger. Inflow to 5. Here, heat is taken from the air in the room to evaporate the refrigerant. On the other hand, the second diaphragm device 6
The refrigerant depressurized by the refrigerant flows into the first refrigerant-refrigerant heat exchanger 7, where it indirectly exchanges heat with the refrigerant gas of the second refrigeration cycle 13 to be described later to absorb and vaporize the refrigerant gas, and the indoor heat exchanger 5 It merges with the refrigerant passing through and is sucked into the compressor 1.

On the other hand, in the second refrigeration cycle 13,
The liquid refrigerant sent by the refrigerant pump 10 flows through the second refrigerant-to-refrigerant heat exchanger 9 to the radiant heat exchanger 12. At this time, since the second refrigerant-to-refrigerant heat exchanger 9 is separated from the first refrigeration cycle 8 by the four-way valve 2, in the second refrigerant-to-refrigerant heat exchanger 9, the liquid refrigerant sent by the refrigerant pump 10 is It flows into the radiant heat exchanger 12 as it is without changing its state. Then, it is evaporated in the radiant heat exchanger 12, contributes to the cooling in the room, and flows into the first refrigerant-to-refrigerant heat exchanger 7. Here, heat is indirectly exchanged with the refrigerant of the first refrigeration cycle 8 described above, and heat is released and liquefied, and then returns to the refrigerant pump 9 again via the reservoir 11. At this time, by arranging the reservoir 11 below the first refrigerant-refrigerant heat exchanger 7 and further arranging the refrigerant pump 10 below the reservoir 11, the refrigerant in the first refrigerant-refrigerant heat exchanger 7 is sufficient. Even if it is not supercooled, the refrigerant can easily maintain the liquid state at the inlet and outlet of the refrigerant pump 10, so that the refrigerant is stably radiated.
Can be sent to. That is, since a stable refrigerant flow rate can be obtained even if the degree of supercooling of the refrigerant in the first refrigerant-refrigerant heat exchanger 7 is small, the degree of supercooling of the refrigerant at the inlet of the radiant heat exchanger 12 can be reduced. Radiant heat exchanger 12
A uniform temperature distribution can be obtained near the entrance of the.

Further, when the operation of the radiant cooling apparatus is started, first, the compressor 1 is started to operate only the first refrigeration cycle 8. As a result, the sensible heat and latent heat (moisture) of the indoor air are removed in the indoor heat exchanger 5, and at the same time the first heat
The refrigerant-refrigerant heat exchanger 7 condenses the refrigerant in the second refrigeration cycle 13 and stores the liquid refrigerant in the liquid storage 11. afterwards,
The refrigerant pump 10 can be started to operate the second refrigeration cycle 13. By doing so, the indoor heat exchanger 5 can lower the indoor air dew point temperature in advance, and at the same time, immediately after the refrigerant pump 10 is started,
The refrigerant can be stably supplied to the radiant heat exchanger 12, and the temperature of the radiant heat exchanger 12 can be rapidly lowered.

Next, a description will be given of the case where the dew point temperature rises in the radiant cooling apparatus, such as when the window is opened. First, the dew point temperature measuring means 15 detects an increase in the dew point temperature of indoor air, and the radiant heat exchanger surface temperature measuring means 14 detects the surface temperature of the radiant heat exchanger 12. In the control device 16 which inputs these dew point temperature and surface temperature, when the dew point temperature rises and approaches the surface temperature, the four-way valve 2 is switched, and the refrigerant of the second refrigeration cycle 13 that has exited the refrigerant pump 10 and The second refrigerant-to-refrigerant heat exchanger 9 indirectly exchanges heat with the refrigerant of the first refrigeration cycle 8 that has been compressed by the compressor 1 and has reached a high temperature. At this time, in the second refrigeration cycle 13,
The liquid refrigerant discharged from the refrigerant pump 10 absorbs heat in the second refrigerant-refrigerant heat exchanger 9 to become a gas refrigerant, and is sent to the radiant heat exchanger 12. In the radiant heat exchanger 12, the gas refrigerant releases a part of the sensible heat or a part of the sensible heat and the latent heat to raise the surface temperature of the radiant heat exchanger 12. Then, the refrigerant is guided to the first refrigerant-to-refrigerant heat exchanger 7 and the first refrigeration cycle 8
Is exchanged with the refrigerant to become a liquid refrigerant, and is sucked into the refrigerant pump 10 again via the liquid storage 11. Therefore, when the dew point temperature rises and approaches the surface temperature, the surface temperature of the radiant heat exchanger 12 can be raised by switching the four-way valve 2 to prevent dew condensation.

As described above, in such a radiant cooling apparatus, the radiant heat exchanger 12 removes the sensible heat of the indoor air while removing the latent heat (moisture) of the indoor air in the indoor heat exchanger 5, thereby providing a mild cooling. In addition, even if the first refrigerant-to-refrigerant heat exchanger 7 does not sufficiently cool the refrigerant, the refrigerant can be stably fed to the radiant heat exchanger 12 and at the same time. The degree of supercooling of the refrigerant at the inlet of the radiant heat exchanger 12 can be reduced, and a uniform temperature distribution can be obtained even near the inlet of the radiant heat exchanger 12. Further, at the start of the operation, the latent heat (moisture) of the indoor air is removed, and the refrigerant can be stably supplied to the radiant heat exchanger 12 immediately after the refrigerant pump 10 is started, and the radiant heat exchanger temperature can be rapidly lowered. . Further, when the dew point temperature rises, the temperature of the radiant heat exchanger 12 can be raised and maintained above the dew point temperature,
Condensation can be prevented.

In the above embodiment, the radiant heat exchanger 10 is used.
Is described as being constituted by a piping pipe attached to the ceiling surface, but the present invention is not limited to this, and is constituted by, for example, an air heat exchanger arranged inside the ceiling chamber, and the ceiling is formed by heat conduction. The surface may be cooled. Further, the indoor heat exchanger 5 may be configured to appropriately introduce outside air to perform ventilation. Further, it is easily possible to provide a new four-way valve (not shown) on the side of the compressor 1 and the outdoor heat exchanger 3 to enable cooling and heating.

[0023]

As is apparent from the above description,
Since the radiant cooling apparatus according to the present invention constitutes the second refrigeration cycle by arranging the first refrigerant-refrigerant heat exchanger higher than the reservoir and the reservoir higher than the refrigerant pump. Even if the refrigerant is not sufficiently subcooled in the first refrigerant-refrigerant heat exchanger, the refrigerant can easily be maintained in the liquid state at the refrigerant pump inlet / outlet, so that the refrigerant can be stably fed to the radiant heat exchanger. Further, it has an advantage that the degree of supercooling of the refrigerant at the inlet of the radiant heat exchanger can be reduced and a uniform temperature distribution can be obtained near the inlet of the radiant heat exchanger.

Further, in the radiant cooling apparatus according to the present invention, when the operation is started, the compressor is activated to operate the first refrigeration cycle, and then the refrigerant pump is activated to operate the second refrigeration cycle. At the same time as removing sensible heat and latent heat (moisture) of indoor air in the indoor heat exchanger 5,
Immediately after the refrigerant pump is activated, the refrigerant can be stably supplied to the radiant heat exchanger, and the radiant heat exchanger temperature can be rapidly lowered.

Further, in the radiant cooling apparatus according to the present invention, when the dew point temperature rises, the refrigerant circulating in the first refrigeration cycle and the refrigerant circulating in the second refrigeration cycle are indirectly connected by the second refrigerant-refrigerant heat exchanger. Since the heat exchange is made possible, by switching the four-way valve according to the dew point temperature, the temperature of the radiant heat exchanger can be raised and maintained above the dew point temperature, which has the advantage of preventing dew condensation. Have.
Therefore, not only the radiant cooling device and the forced draft cooling device can be organically coupled, but also the radiant cooling device can be stably started even at the start of operation, and there is no fear of dew condensation even when the humidity suddenly rises.

[Brief description of drawings]

FIG. 1 is an air conditioning circuit diagram showing an embodiment of a radiation cooling device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 1st expansion device 5 Indoor heat exchanger 6 2nd expansion device 7 1st refrigerant-refrigerant heat exchanger 8 1st refrigeration cycle 9 2nd refrigerant-refrigerant heat exchanger 10 Refrigerant pump 11 Reservoir 12 Radiant heat exchanger 13 Second refrigeration cycle 14 Radiant heat exchanger Surface temperature measuring means 15 Dew point temperature measuring means 16 Control device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Yoshida 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. At least a compressor, an outdoor heat exchanger, a first expansion device, an indoor heat exchanger are connected in this order, and a second expansion device and a first refrigerant-refrigerant heat exchanger are connected in series,
A first refrigeration cycle in which the first expansion device and the indoor heat exchanger are connected in parallel with each other, and at least a refrigerant pump, a radiant heat exchanger, the first refrigerant-to-refrigerant heat exchanger, a storage And a second refrigeration cycle in which the first refrigerant-refrigerant heat exchanger is arranged higher than the reservoir and the reservoir is arranged higher than the refrigerant pump. A radiant cooling apparatus, wherein the refrigerant circulating in the first refrigeration cycle and the refrigerant circulating in the second refrigeration cycle can be indirectly heat-exchanged by the first refrigerant-refrigerant heat exchanger. 2. The radiant cooling apparatus according to claim 1, wherein after the compressor is activated to operate the first refrigeration cycle, the refrigerant pump is activated to operate the second refrigeration cycle. . 3. A measuring means for measuring the surface temperature of the radiant heat exchanger, and a dew point temperature measuring means for measuring the dew point temperature in the vicinity of the radiant heat exchanger are provided at the outlet of the refrigerant pump of the second refrigeration cycle. A second refrigerant-to-refrigerant heat exchanger is connected, a four-way valve and the second refrigerant-to-refrigerant heat exchanger are connected between the compressor and the outdoor heat exchanger of the first refrigeration cycle, and the dew point is The refrigerant circulating in the first refrigeration cycle and the refrigerant circulating in the second refrigeration cycle are indirectly transferred to the second refrigerant-refrigerant heat exchanger by switching the four-way valve in accordance with the output of the temperature measuring means. The radiant cooling apparatus according to claim 1, wherein heat is exchanged.