CN104380002A - Radiation-type air conditioner - Google Patents

Abstract

The invention provides a radiant air conditioner. The radiant air conditioner (1) includes an outdoor unit (10) and a radiant panel (30) arranged indoors. The outdoor unit is provided with an outdoor heat exchanger (14) and a compressor (12) that circulates refrigerant through the radiant panel and the outdoor heat exchanger. An expansion valve (15) and a solenoid valve (25) are disposed on refrigerant piping (17, 18) connected to the radiation panel. When the controller (40) of the radial air conditioner stops the operating compressor, the expansion valve and the electromagnetic valve are brought into a small opening state.

Description

Radiant air conditioner

technical field

The present invention relates to radiant air conditioners.

Background technique

In a heat pump air conditioner for residential use, that is, a so-called separate air conditioner in which the outdoor unit and the indoor unit are separated, the usual structure is that the outdoor unit is provided with a heat exchanger and a fan, and the indoor unit is also provided with a heat exchanger. and fan. On the other hand, there is also a separate type air conditioner in which the heat exchanger of the indoor unit is a radiant panel, and the indoor cooling or heating is performed by heat radiation without using a fan. Patent Document 1 shows an example thereof.

The air conditioner described in Patent Document 1 includes a radiation panel arranged on the ceiling of a house. The refrigerant piping is arranged in a serpentine shape inside the radiation panel. During cooling operation, the radiant panels absorb heat for radiant cooling. During heating operation, the radiant panel dissipates heat for radiant heating. Radiant cooling and heating do not have the agitation and noise of the indoor fan to the air, and can perform cooling and heating quietly and comfortably.

Patent Document 1: Japanese Patent Laid-Open Publication No. Hei 10-205802

In an air conditioner, in general, during operation of the compressor, the refrigerant pressure on the discharge side of the compressor is high, and the refrigerant pressure on the suction side of the compressor is low. In order to balance the pressure in the refrigeration system when the compressor is stopped, the refrigerant moves from a place with high pressure to a place with low pressure. In a radiant air conditioner, for example, when the compressor stops during cooling operation, the temperature of the radiant panel rises due to the outflow of low-temperature refrigerant from the radiant panel and the inflow of high-temperature refrigerant, so that the cooled room air is heated. . When the compressor stops during heating operation, high-temperature refrigerant flows out of the radiant panel, the temperature of the radiant panel drops, and the warm indoor air is cooled.

Contents of the invention

In view of the above circumstances, an object of the present invention is to provide a radiant air conditioner capable of extending the cooling and heating effect as much as possible when the compressor is stopped during the cooling and heating operation.

The radiant air conditioner of the present invention includes: a radiant panel arranged indoors; an outdoor heat exchanger; a compressor for circulating refrigerant through the radiant panel and the outdoor heat exchanger through refrigerant piping; and a valve disposed on the refrigerant piping connected to the radiation panel, and when the control unit stops the operating compressor, the control unit opens the valve slightly. degree status.

In the radiant air conditioner configured as described above, it is preferable that the valve is disposed on the refrigerant pipe on the refrigerant inflow side with respect to the radiant panel and on the refrigerant pipe on the refrigerant outflow side with respect to the radiant panel. Agent piping on both sides.

In the radiant air conditioner configured as described above, it is preferable that the valve is an expansion valve.

In the radiation type air conditioner of the said structure, it is preferable that the state of the said small opening degree is fully closed.

According to the present invention, when the operating compressor is stopped, since the valve in the refrigerant piping is in a small opening state, the refrigerant in the radiant panel does not move easily, and the temperature of the radiant panel does not change rapidly. Therefore, the cooling and heating effect brought by the radiant panel can be continued.

Description of drawings

Fig. 1 is a schematic configuration diagram of a radiant air conditioner according to the present invention, showing the state during cooling operation.

Fig. 2 is a schematic configuration diagram of the radiant air conditioner of the present invention, showing the state during heating operation.

Fig. 3 is a schematic configuration diagram showing a first embodiment of a radiation panel.

Fig. 4 is a schematic configuration diagram showing a second embodiment of the radiation panel.

Fig. 5 is a cross-sectional view showing the first embodiment of the heat dissipation unit.

Fig. 6 is a cross-sectional view showing a second embodiment of the heat dissipation unit.

Fig. 7 is a control block diagram of the radiant air conditioner.

Explanation of reference signs

1 Radiant air conditioner

10 outdoor unit

11 box

12 compressors

13 Four-way valve

14 outdoor heat exchanger

15 expansion valve

16 outdoor side blower

17, 18 Refrigerant piping

25 solenoid valve

30 radiant panels

31 box

32 Heat sink

36 temperature detector

40 Control Department

Detailed ways

The schematic structure of the radiant air conditioner 1 is demonstrated based on FIG. 1. FIG. The radiant air conditioner is composed of an outdoor unit 10 and a radiant panel 30 . The radiant panel 30 is arranged indoors, and corresponds to an indoor unit of a common split-type air conditioner.

The outdoor unit 10 houses a compressor 12, a four-way valve 13, an outdoor heat exchanger 14, an expansion valve 15, and an outdoor blower 16, etc. inside a box body 11, which is made of sheet metal parts and synthetic resin parts. . As the expansion valve 15, an expansion valve whose opening degree can be controlled is used.

The outdoor unit 10 is connected to the radiation panel 30 through two refrigerant pipes 17 and 18 . The refrigerant piping 17 is used for passing a liquid refrigerant, and is thinner than the refrigerant piping 18 . Therefore, the refrigerant pipe 17 is also called a "liquid pipe", a "thin pipe" and the like. The refrigerant piping 18 is used for passing a gas refrigerant, and is thicker than the refrigerant piping 17 . Therefore, the refrigerant pipe 18 is also called a "gas pipe", a "thick pipe", or the like. As the refrigerant, for example, HFC-based R410a, R32, and the like are used.

Among the refrigerant pipes inside the outdoor unit 10 , the refrigerant pipe connected to the refrigerant pipe 17 is provided with a two-way valve 19 , and the refrigerant pipe connected to the refrigerant pipe 18 is provided with a three-way valve 20 . When the refrigerant pipes 17 and 18 are removed from the outdoor unit 10, the two-way valve 19 and the three-way valve 20 are closed to prevent the refrigerant from leaking from the outdoor unit 10 to the outside. When the refrigerant needs to be discharged from the outdoor unit 10 or the entire refrigeration system including the radiant panel 30 , the refrigerant is discharged through the three-way valve 20 . In addition, a solenoid valve 25 is provided on the refrigerant piping between the three-way valve 25 and the four-way valve 13 .

The radiant panel 30 is usually erected near the indoor wall, and a plurality of heat dissipation parts 32 are disposed inside a rectangular box 31 made of sheet metal and synthetic resin. Although named "radiation part" for simplicity, this member not only dissipates heat to ambient air during heating operation, but also absorbs heat from ambient air during cooling operation.

The heat dissipation portion 32 is a cylindrical member arranged vertically. As shown in FIGS. 5 and 6 , the structure in which the central refrigerant pipe 33 is surrounded by fins 34 is the basic structure of the heat dissipation portion 32 . The refrigerant tubes 33 and the fins 34 are formed of metals having good thermal conductivity such as copper and aluminum, and are in close contact with each other. In addition, the term "vertical" here is not limited to a strict vertical direction. It may also be a vertical direction including a certain inclination.

Both the heat sink 34 in FIG. 5 and the heat sink 34 in FIG. 6 have a horizontal cross-sectional shape in which a plurality of fins spread radially. The fin 34 in FIG. 5 is formed as a member divided into two in the axial direction, and sandwiches the refrigerant tube 33 from the front and rear. The fin 34 in FIG. 6 is a single member, and the refrigerant tube 33 is inserted into the center part corresponding to the hub of the wheel. Of course, the structure of the heat dissipation portion 32 shown in FIGS. 5 and 6 is only an example, and heat dissipation fins 34 with different cross-sectional shapes can be used, and the refrigerant tubes 33 and heat dissipation fins 34 can also be combined in different ways.

A plurality of (seven in the figure) heat dissipation parts 32 are arranged in parallel with each other inside the housing 31 . The front surface of the box body 31 is provided with an opening 35 exposing the heat dissipation portion 32 . All of the plurality of radiators 32 are connected to the refrigerant pipes 17 and 18 . In the connection structure example shown in FIG. 3 , all the radiators 32 are connected in parallel to the refrigerant pipes 17 and 18 . In the connection structure example shown in FIG. 4 , all the radiators 32 are connected in series to the refrigerant pipes 17 and 18 .

In order to connect the plurality of radiating parts 32 , other methods than those shown in FIGS. 3 and 4 may be used. For example, a plurality of heat dissipation parts 32 may be grouped by a predetermined number, the heat dissipation parts 32 belonging to the same group may be connected in parallel, and each group may be connected in series. Alternatively, a plurality of radiating parts 32 may be grouped by a predetermined number, the radiating parts 32 belonging to the same group may be connected in series, and each group may be connected in parallel.

When performing operation control of the radiant air conditioner 1, it is necessary to know the temperature of each part. To achieve this, the outdoor unit 10 and the radiation panel 30 are equipped with temperature detectors. In the outdoor unit 10, the temperature detector 21 is arranged on the outdoor side heat exchanger 14, the temperature detector 22 is arranged on the discharge pipe 12a which is the discharge part of the compressor 12, and the temperature detector 22 is arranged on the suction pipe 12a which is the discharge part of the compressor 12. The temperature detector 23 is arranged on the suction pipe 12 b of the section, and the temperature detector 24 is arranged on the refrigerant piping between the expansion valve 15 and the two-way valve 19 . A temperature detector 36 is arranged on the radiation panel 30 . The temperature detectors 21, 22, 23, 24, and 36 are all composed of thermistors.

As shown in FIG. 3 , although the temperature detector 36 is used to measure the temperature of the radiator 32 , it is not directly attached to the radiator 32 but is attached to the refrigerant pipe 17 for liquid refrigerant. The reason for disposing the temperature detector 36 on the refrigerant pipe 17 is as follows. That is, since the temperature of the heat dissipation portion 32 differs depending on the position (particularly, the upper and lower positions), it is difficult to determine at which position the temperature detector 36 is to be arranged.

The surface temperature of the heat dissipation part 32 also depends on the design of the refrigerant channel connecting the plurality of heat dissipation parts 32 . When the refrigerant channel is a single channel, a temperature difference is likely to occur due to pressure loss and gas-liquid phase change of the refrigerant. When the refrigerant passage is a plurality of passages, there is a possibility of a temperature difference among the passages. In addition, the temperature detector may be covered with metal to improve temperature sensitivity. When the metal constituting the heat sink 32 is different from the metal used in the temperature detector, there is a possibility that a potential difference may occur at the contact portion due to the dissimilar metal, thereby causing galvanic corrosion. In any case, it is difficult to determine where the temperature detector 36 is to be placed on the heat dissipation unit 32 .

If the refrigerant pipe 17 inside the tank 31 is used as the installation location of the temperature detector 36, the above-mentioned problem can be solved. The refrigerant pipe 17 is a portion where the refrigerant throttled by the expansion valve 15 flows in during the cooling operation, and a portion where the condensed refrigerant flows out from the radiator 32 during the heating operation.

During the cooling operation, since the refrigerant in the gas-liquid two-phase state flows through the refrigerant pipe 17 (although it is hardly vaporized, but the refrigerant in the state with a lot of liquid-phase refrigerant), in other words, because the Since there is little change in the gas-liquid phase, the temperature of the refrigerant pipe 17 can be treated as the temperature of the radiator 32 . On the other hand, during the heating operation, the refrigerant pipe 17 becomes the subcooling part (liquid phase part) of the refrigeration system, and since the liquid refrigerant is accumulated, the temperature of the refrigerant pipe 17 cannot be directly used as the temperature of the heat dissipation part 32. deal with. However, by appropriately correcting the temperature, the surface temperature of the radiator 32 can also be obtained from the temperature measured by the temperature detector 36 during the heating operation. The temperature correction value is determined experimentally.

The installation position of the temperature detector 36 is an upper portion of the refrigerant pipe 17 inside the casing 31 . The reason why such a location is selected as the installation location of the temperature detector 36 will be described later.

The control unit 40 shown in FIG. 7 is used for overall control of the radiant air conditioner 1 . The control unit 40 performs control so that the indoor temperature reaches the target value set by the user.

The control unit 40 issues operation commands to the compressor 12 , the four-way valve 13 , the expansion valve 15 , the outdoor air blower 16 and the electromagnetic valve 25 . Moreover, the control part 40 receives the output signal of the detected temperature from the temperature detectors 21-24 and the temperature detector 36, respectively. The control unit 40 refers to the output signals from the temperature detectors 21 to 24 and the temperature detector 36 to issue operation instructions to the compressor 12 and the outdoor air blower 16, and to issue state switching instructions to the four-way valve 13, the expansion valve 15, and the solenoid valve 25. instruction.

FIG. 1 shows a state where the radiant air conditioner 1 is performing cooling operation (dehumidification operation) or defrosting operation. The high-temperature and high-pressure refrigerant discharged from the compressor 12 enters the outdoor heat exchanger 14, where it exchanges heat with outdoor air. That is, the refrigerant dissipates heat to the outdoor air. The refrigerant that radiates heat and condenses into liquid is sent from the outdoor heat exchanger 14 through the expansion valve 15 to the heat dissipation portion of the radiation panel 30 , decompresses and expands to become a low temperature and low pressure, thereby reducing the surface temperature of the heat dissipation portion 32 . The radiating part 32 whose surface temperature has dropped absorbs heat from the indoor air, thereby cooling the indoor air. The low-temperature gaseous refrigerant that has absorbed heat is returned to the compressor 12 . The airflow generated by the outdoor air blower 16 promotes heat dissipation from the outdoor heat exchanger 14 .

FIG. 2 shows a state where the radiant air conditioner 1 is performing a heating operation. At this time, the four-way valve 13 is switched so that the flow direction of the refrigerant is opposite to that during cooling operation. That is, the high-temperature and high-pressure refrigerant discharged from the compressor 12 enters the radiator 32, where it exchanges heat with indoor air. That is, the refrigerant dissipates heat to the indoor air to heat the indoor air. The refrigerant that radiates heat and condenses to become a liquid is sent from the radiator 32 to the outdoor heat exchanger 14 through the expansion valve 15 , depressurizes and expands to lower the surface temperature of the outdoor heat exchanger 14 . The outdoor side heat exchanger 14 whose surface temperature has been lowered absorbs heat from the outdoor air. The low-temperature gaseous refrigerant that has absorbed heat is returned to the compressor 12 . The airflow generated by the outdoor side blower 16 promotes heat absorption by the outdoor side heat exchanger 14 . Frost adhering to the outdoor heat exchanger 14 due to heat absorption is removed by the defrosting operation.

During the heating operation, temperature detection is performed by the temperature detector 36 . As described above, the temperature detector 36 is disposed on the refrigerant pipe 17 and does not directly detect the surface temperature of the radiation panel 30 (more precisely, the surface temperature of the heat dissipation portion 32 ). In addition, the difference between the temperature of the refrigerant pipe 17 and the surface temperature of the radiation panel 30 also changes depending on the value of the degree of subcooling. Therefore, the surface temperature of the radiation panel 30 is predicted by predicting the degree of subcooling of the radiator 32 from the temperature of the refrigerant pipe 17 during the heating operation and correcting the temperature. As described above, the correction temperature is determined in advance through experiments.

As described above, the control unit 40 performs the heating operation control of the radiant air conditioner 1 with reference to the surface temperature of the radiant panel 30 obtained by correcting the temperature detected by the temperature detector 36 .

During the heating operation, the control unit 40 checks whether the radiation panel 30 has reached a temperature higher than or equal to a set temperature. The temperature detection at this time may also use the temperature detector 36 . In this way, by using the temperature detector 36 to check whether the radiation panel 30 has reached a temperature higher than the set temperature, that is, by using the temperature detector 36 for air conditioning control as a temperature detector for protection, the control of the radiation type air conditioner 1 can be simplified. system.

During the cooling operation (dehumidification operation) or the defrosting operation, the temperature detected by the temperature detector 36 can be treated as the surface temperature of the radiator 32 . Therefore, temperature correction as in heating operation is unnecessary.

As described above, since the temperature detector 36 is installed on the part of the refrigerant pipe 17 located in the case 31, it can be connected with the refrigerant passage of the radiant panel 30 whether it is a refrigerant passage during cooling operation or a cooling passage during heating operation. Regardless of the agent passage, the surface temperature of the radiation panel 30 is detected at the same position. Therefore, it is not necessary to change the control method between cooling operation and heating operation.

During the cooling operation (dehumidification operation), dew is generated on the radiator 32 . Since the temperature detector 36 is installed on the upper part of the refrigerant pipe 17 in the casing 31, even if the dew in the heat dissipation part 32 remains under the heat dissipation part 32 as drain water The drain pan shown in the figure accepts the drain water), and the temperature detector 36 will not be in contact with the drain water. Therefore, there is no need to worry about errors in the detected temperature of the temperature detector 36 or failure of the temperature detector 36 . Although it is not as serious as the radiating part 32, dew also occurs on the refrigerant pipe 17, and it is also effective to arrange the temperature detector 36 above the refrigerant pipe 17 in order to reduce the influence of the dew.

Even when a plurality of radiating units 32 are connected in series as shown in FIG. 4 , the temperature detecting unit 36 is arranged above the refrigerant pipe 17 . In other words, it is necessary to arrange the temperature detector 36 in a place where dew is less likely to occur.

When it is necessary to stop the compressor 12 during the cooling operation (during the dehumidification operation) or during the heating operation, the control unit 40 switches the expansion valve 15 and the electromagnetic valve 25 to a small opening state. At this time, the movement of the refrigerant becomes difficult, and since the refrigerant in the radiation panel 30 becomes difficult to move, the temperature of the radiation panel 30 is prevented from rapidly changing. In this way, the cooling and heating effect brought by the radiation panel 30 can be maintained. Here, the meaning of "small opening" also includes "fully closed".

In a normal non-radiant air conditioner in which indoor air is circulated by an indoor air blower, when the compressor is stopped during cooling operation, the indoor air blower can continue to operate. This allows the user to continue to feel cool. However, since the radiant air conditioner does not have a blower on the indoor side, it is not possible to enjoy the coolness of the blown air. If the refrigerant at the temperature during the cooling operation is kept in the radiant panel, you can enjoy a cool feeling even if it does not last for a long time. When the refrigerant at the temperature of the heating operation is kept in the radiant panel, it also keeps warm although not for a long time. When the operating compressor is stopped in this way, the method of making the opening of the valve in the refrigerant piping small is particularly effective in the radiant air conditioner.

In addition, since the cooled refrigerant or heated refrigerant can be kept in the radiant panel for a long time, compared with the case where the valve opening is increased immediately after the compressor is stopped to achieve pressure balance of the refrigerant, it is possible to further extend the Cools or heats room air. Therefore, in thermal on-off control (control to stop the compressor when the surface temperature of the radiant panel reaches the target temperature, and restart the compressor when the surface temperature of the radiant panel deviates from the target temperature), the time from stopping to restarting of the compressor is prolonged, Thereby saving energy. In addition, when the cooling and heating operation is stopped by turning off the timer or when the user stops the cooling and heating operation by using a remote control, etc., since the effect of cooling and heating can be continued temporarily, energy can be used efficiently.

The radiant panel is considerably larger (for example, the volume ratio is nearly twice that of the indoor side heat exchanger of a normal split-type air conditioner in which the indoor air is circulated by the indoor side blower. In addition, it sometimes occupies the entire ceiling and the entire wall. noodle). Therefore, energy can be efficiently used by performing the control of the present invention.

As a timing for stopping the compressor 12 and switching the expansion valve 15 and the solenoid valve 25 to a small opening, the compressor 12 may be stopped first, or the expansion valve 15 and the solenoid valve 25 may be switched to a small opening first. Or start at the same time. In the case of stopping the compressor 12 first, the shock at the time of switching the expansion valve 15 and the solenoid valve 25 to a small opening can be reduced, but conversely cannot be avoided while the expansion valve 15 and the solenoid valve 25 are switched to a small opening Refrigerant moves. If the expansion valve 15 and the electromagnetic valve 25 are switched to a small opening first, although it is possible to make it difficult for the refrigerant to move immediately, there is a problem of conversely causing a shock to the refrigeration system. Which method to choose can be considered in combination with the strength of the structural elements of the refrigeration system.

When restarting the stopped compressor 12, it is preferable to first set the expansion valve 15 and the solenoid valve 25 with a small opening to a large opening. This is to prevent pressure difference when the compressor 12 is started up again, and thus to facilitate start-up. If it is a state of small opening (for example, when the valve opening has stages from 0 (fully closed) to 512 (fully open), the opening is about 1 to 10), the high pressure side and the constant pressure side are gradually obtained. pressure balance. Therefore, when the valve is fully opened before restarting the compressor 12, the pressure difference between the low-pressure side and the high-pressure side becomes smaller than when the compressor 12 is set to be fully open while the opening degree remains fully closed until the compressor 12 is restarted. Small. This provides an effect that refrigerant noise is less likely to be generated when the valve is fully opened before the compressor 12 is restarted. In addition, it is only necessary to find the appropriate small opening state through experiments. In addition, the timing of achieving pressure balance may be just before the restart of the compressor 12, and may not be immediately before the restart.

Instead of the electromagnetic valve 25 with a variable opening as described above, a solenoid valve with only two states in which the small opening is fully closed and the large opening is fully open can be used. In addition, an electromagnetic valve may be additionally provided between the expansion valve 15 and the two-way valve 19 and set to a small opening.

In the present embodiment, the expansion valve 15 is used not only for the original purpose but also for making it difficult for the refrigerant to move. By making the expansion valve 15 perform two functions in this way, the structure can be simplified. However, a solenoid valve similar to the solenoid valve 25 may be disposed on the expansion valve 15 side.

In addition, in this embodiment, by providing the electromagnetic valve 25 other than the expansion valve 15, a configuration is formed in which the refrigerant pipe on the refrigerant inflow side with respect to the radiation panel 30 and the refrigerant pipe on the refrigerant outflow side with respect to the radiation panel 30 are arranged. Valves are installed on both sides of the refrigerant piping. However, the solenoid valve 25 may also be eliminated, and only the expansion valve 15 may assume the role of making it difficult for the refrigerant to move.

It has been described so far that the radiating portion 32 is arranged vertically, but the radiating portion 32 may be arranged horizontally. In this case, the fins 34 may be a plurality of thin plates perpendicular to the axis of the refrigerant tube 33 spaced apart from each other.

Embodiments of the present invention have been described above, but the scope of the present invention is not limited thereto, and various modifications can be made and implemented without departing from the gist of the invention.

Industrial Applicability

The present invention can be widely applied to radiant air conditioners.

Claims (5)

1. a radiant type air conditioner, is characterized in that comprising:

Radiant panel, is configured in indoor;

Outdoor heat exchanger;

Compressor, makes cold-producing medium circulate in described radiant panel and described outdoor heat exchanger by refrigerant piping;

Control part; And

Valve, is configured on the described refrigerant piping that is connected with described radiant panel,

When described control part makes the described compressor in running become halted state, described control part makes described valve become the state of small guide vane.

2. radiant type air conditioner according to claim 1, it is characterized in that, described valve is configured in be become the described refrigerant piping of refrigerant inflow side relative to described radiant panel and becomes the described refrigerant piping both sides of refrigerant outflow side relative to described radiant panel.

3. radiant type air conditioner according to claim 1, is characterized in that, described valve is expansion valve.

4. radiant type air conditioner according to claim 2, is characterized in that, described valve is expansion valve.

5. according to the radiant type air conditioner in Claims 1 to 4 described in any one, it is characterized in that, the state of described small guide vane is full cut-off.