JPH04369327A - Air conditioner - Google Patents

Abstract

PURPOSE:To adjust the amount of refrigerant with a simplified structure for stabilization of a freezing cycle and improvement of cooling/heating capability. CONSTITUTION:There are provided a radiation cooling panel 10, and a radiation heating panel 4. In cooling, supercooling is evaluated by temperature sensors 27, 20 provided at the center of an outdoor heat exchanger and at an outlet on the basis of a temperature difference between the center of the outdoor heat exchanger 7 and the outlet. On the basis of the supercooling, there are controlled a solenoid valve 22 and an expansion valve 25 located at an outlet of the radiation heating panel 4, while in heating supercooling is evaluated from a temperature difference between an inlet of the radiation heating panel 4 and the outlet detected by temperature sensors 23, 24 disposed at the inlet and outlet of the radiation heating panel 4, and expansion valves 28, 21 disposed at an inlet and an outlet of the radiation cooling panel 10 are controlled using the evaluated supercooling.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner.

0002

[Prior Art] Generally, in a refrigeration cycle using a refrigerant,
For example, the degree of supercooling of the refrigerant is adjusted by adjusting the operation of the compressor depending on the cooling load. However, when the amount of load fluctuation is large, the degree of supercooling cannot be adjusted sufficiently by adjusting the compressor alone. Furthermore, when cooling and heating are performed in one system, the amount of refrigerant required for cooling and heating differs, making it more difficult to adjust the degree of supercooling. To solve this problem, some large air conditioners are equipped with a separate receiver for storing refrigerant to adjust the amount of refrigerant.

0003

However, if an air conditioner is provided with a receiver for storing refrigerant, the device becomes large and expensive. On the other hand, in order to stabilize the refrigeration cycle, it is better for the refrigerant in front of the expansion valve to be in a liquid state, and to keep the refrigerant in a stable liquid state, it is necessary to maintain the degree of subcooling of the refrigerant constant as described above. be. If the degree of subcooling of the refrigerant is small, refrigerant bubbles will occur in the liquid refrigerant, making the pressure reduction effect at the expansion valve unstable, and the refrigerant flow rate and evaporation temperature will be inconsistent, reducing the performance of the refrigeration cycle. Furthermore, when the degree of supercooling is large, both high and low pressures in the pressure-enthalpy curve become high, reducing the amount of heat exchanged by the heat exchanger and degrading the performance of the refrigeration cycle. If there is a large amount of refrigerant relative to the heating and cooling load, the degree of subcooling will increase, and if there is a small amount of refrigerant, the degree of subcooling will decrease, so it is still necessary to adjust the amount of refrigerant.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an air conditioner that can adjust the amount of refrigerant with a simple configuration.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the air conditioner of the present invention is first of all an air conditioner that can be heated and cooled and equipped with a radiant cooling panel and a radiant heating panel. Second, it is equipped with a refrigerant amount adjustment means that adjusts the amount of refrigerant so that the degree of subcooling is always appropriate by using the radiant heating panel as a refrigerant reservoir during cooling and the radiant cooling panel as a refrigerant reservoir during heating. shall be.

[0006]

[Operation] In the air conditioner of the present invention, two types of radiant panels, a radiant cooling panel and a radiant heating panel, operate as a radiant panel and a refrigerant reservoir, respectively. That is, depending on the air conditioning load, the refrigerant amount adjusting means operates to store refrigerant in the radiant heating panel during cooling, and adjusts refrigerant to the radiant cooling panel during heating, thereby adjusting the amount of refrigerant and preventing overheating. Cooling degree is adjusted appropriately.

[0007]

[Examples] The present invention will be further explained by showing Examples and Comparative Examples below. First, an example of a comparative air conditioner using forced convection and radiation is shown in the schematic configuration diagram of FIG. 2. This device consists of a compressor 1, a four-way valve 2, an outdoor heat exchanger 7, an indoor heat exchanger 3, a radiant cooling panel 10, an expansion valve 9 for the indoor heat exchanger, a radiant cooling panel inlet expansion valve 8, and a radiant cooling panel outlet expansion valve. Valve 11, radiant heating panel outlet expansion valve 5, heating check valve 15
, radiant cooling panel check valve 12 , cooling check valve 6 and indoor fan 13 , outdoor fan 14 , suction temperature sensor 16
, radiant cooling panel inlet temperature sensor 17, radiant cooling panel outlet temperature sensor 18, indoor heat exchanger temperature sensor 1
9. Consists of outdoor heat exchanger temperature sensor 20, 1
It forms the system's refrigeration cycle. The operation of this device will be explained below. In the case of cooling, the high-temperature, high-pressure refrigerant discharged from the compressor 1 passes through the outdoor heat exchanger 7, exchanges heat with the outside air driven by the outdoor fan 14, radiates heat, condenses and liquefies, and cools the air, as shown by the solid line. Since the flow in this direction is stopped by the non-return valve 6, the flow reaches the indoor heat exchanger expansion valve 9 and the radiant cooling panel inlet expansion valve 8. At this time, the refrigerant that has passed through the expansion valve 9 for the indoor heat exchanger is depressurized and becomes a low-pressure gas-liquid two-phase state, and then heat exchanges with the indoor air driven by the indoor fan 13 in the indoor heat exchanger 3 to produce evaporated air. After it becomes low-temperature, low-pressure steam, it passes through the four-way valve 2 and is sucked into the compressor 1 again. At this time, the indoor air is cooled and the room can be cooled. On the other hand, the refrigerant that has reached the radiant cooling panel inlet expansion valve 8 is adjusted in flow rate and depressurized to become a low-temperature, low-pressure gas-liquid two-phase state.
leading to. The refrigerant that has reached the radiant cooling panel 10 collects heat from the room through radiation and natural convection, evaporates, and reaches the radiant cooling panel outlet expansion valve 11 . At this time, the evaporation temperature of the radiant cooling panel 10 is detected by the radiant cooling panel inlet sensor 17, and the temperature of the radiant cooling panel 10 is changed by controlling the evaporation temperature of the refrigerant according to the valve opening degree of the radiant cooling panel outlet expansion valve 11. This allows the panel temperature to match the dew point of the indoor air. Thereafter, the refrigerant passes through the check valve 12, merges with the refrigerant that has passed through the indoor heat exchanger 3, and is sucked into the compressor 1 again, repeating the cycle. Here, the dew point temperature of the indoor air is detected by a dew point sensor installed indoors, and the radiant cooling panel 1
The temperature of the refrigerant flowing through the radiation cooling panel 10 is controlled so that no dew condensation occurs on the surface of the cooling panel 10.

Regarding the control of the refrigeration cycle, a radiant cooling panel outlet temperature sensor 18 detects the refrigerant outlet temperature of the radiant cooling panel 10, a radiant cooling panel inlet temperature sensor 17 detects the refrigerant evaporation temperature of the radiant cooling panel 10, Determine the degree of superheating of the refrigerant, and check the radiant cooling panel inlet expansion valve 8.
and adjusts the degree of superheating of the refrigerant at the outlet of the radiant cooling panel 10. In addition, the suction temperature sensor 16 detects the refrigerant suction temperature of the compressor, the indoor heat exchanger temperature sensor 19 detects the evaporation temperature of the indoor heat exchanger, determines the degree of refrigerant superheating, and controls the expansion valve 9 for the indoor heat exchanger. , adjusts the degree of superheating of the refrigerant sucked into the compressor. Regarding the evaporation temperature of the radiant cooling panel 10, as described above, the evaporation temperature of the radiant cooling panel 10 is detected by the radiant cooling panel inlet temperature sensor 17, and the radiant cooling panel outlet expansion valve 11 is controlled. Adjust the evaporation temperature of By repeating these controls, the refrigeration cycle can be operated normally without causing dew condensation on the surface of the radiant cooling panel 10.

In the case of heating, the high-temperature, high-pressure refrigerant discharged from the compressor 1 passes through the four-way valve 2, as shown by the dotted line, and the flow in this direction is stopped by the radiant cooling panel check valve 12. 3, it exchanges heat with the indoor air driven by the indoor fan 13, radiates heat, condenses and liquefies, and since the flow in this direction is stopped by the heating check valve 15, it reaches the radiant heating panel 4, and the radiant heating panel 4 After heating to a high temperature, it becomes a low-pressure gas-liquid two-phase state at the radiant heating panel outlet expansion valve 5, passes through the cooling check valve 6, and is transferred to the outdoor heat exchanger 7.
leading to. After exchanging heat with outside air driven by the outdoor fan 14 in the outdoor heat exchanger 7 and evaporating it into low-temperature, low-pressure steam, it passes through the four-way valve 2 and is sucked into the compressor 1 again. At this time, the indoor heat exchanger 3 heats the indoor air to heat the room, and the radiant heating panel 4 heats the room by radiation and natural convection. Regarding the control of the refrigeration cycle, the suction temperature sensor 16 detects the suction refrigerant temperature of the compressor, the outdoor heat exchanger temperature sensor 20 detects the refrigerant evaporation temperature of the outdoor heat exchanger, and calculates the degree of refrigerant superheating.
The expansion valve 5 for the radiant heating panel is controlled to adjust the degree of superheating of the refrigerant sucked into the compressor.

The disadvantage of the above air conditioner is that when the amount of load fluctuation is large, the degree of supercooling cannot be adjusted sufficiently by adjusting the compressor alone, and furthermore, the amount of refrigerant required for cooling and heating is Because of the difference, the degree of supercooling cannot be adjusted sufficiently depending on cooling and heating.

The embodiment of the present invention solves the above problem. FIG. 1 is a schematic diagram of an air conditioner according to an embodiment of the present invention. This device consists of a compressor 1, a four-way valve 2, an outdoor heat exchanger 7, an indoor heat exchanger expansion valve 29, an indoor heat exchanger 3, a radiant cooling panel inlet expansion valve 28, a radiant cooling panel 10, and a radiant cooling panel outlet expansion valve. Valve 21, solenoid valve 22, radiant heating panel 4, radiant heating panel outlet expansion valve 25, indoor fan 13
, outdoor fan 14, suction temperature sensor 16, radiant cooling panel inlet temperature sensor 17, radiant cooling panel outlet temperature sensor 18, indoor heat exchanger temperature sensor 19, outdoor heat exchanger temperature sensor 20, outdoor heat exchanger central temperature sensor 27 , a radiant heating panel inlet temperature sensor 23, and a radiant heating panel outlet temperature sensor 24, and is a single-system refrigeration cycle. The solenoid valve 22 is provided in the middle of the path through which the refrigerant flows from the indoor heat exchanger outlet to the radiant heating panel inlet during heating operation. Further, a radiant heating panel inlet temperature sensor 23 and a radiant heating panel outlet temperature sensor 24 are provided near the inlet and outlet of the radiant heating panel along the flow of refrigerant during heating operation. Furthermore, an outdoor heat exchanger center temperature sensor 27 is provided to detect the temperature at approximately the center of the outdoor heat exchanger. Indoor heat exchanger expansion valve 29, radiant cooling panel inlet expansion valve 28, radiant cooling panel outlet expansion valve 21, radiant heating panel outlet expansion valve 25
The refrigerant flow is reversible and has the function of preventing refrigerant from flowing if it is fully closed. The operation of this device will be explained below. In the case of cooling, as shown by the solid line, the high-temperature, high-pressure refrigerant discharged from the compressor 1 reaches the outdoor heat exchanger 7, exchanges heat with the outside air driven by the outdoor fan 14, radiates heat, and condenses to liquefy. The refrigerant leaving the outdoor heat exchanger 7 reaches the indoor heat exchanger expansion valve 29 and the radiant cooling panel inlet expansion valve 28 .

The refrigerant that has passed through the indoor heat exchanger expansion valve 29 is depressurized and becomes a low-pressure gas-liquid two-phase state, and then is evaporated by exchanging heat with the indoor air driven by the indoor fan 13 in the indoor heat exchanger 3. After it is vaporized and becomes low-temperature, low-pressure steam, it passes through the four-way valve 2 and is sucked into the compressor 1 again. At this time, the indoor air is cooled to cool the room.

The refrigerant that has reached the radiant cooling panel inlet expansion valve 28 is subjected to flow rate adjustment and pressure reduction, and reaches the radiant cooling panel 10 after being in a gas-liquid two-phase state at low temperature and low pressure. The refrigerant that has reached the radiant cooling panel 10 collects heat from the room through radiation and natural convection, evaporates, and reaches the radiant cooling panel outlet expansion valve 21 . At this time, the evaporation temperature of the radiant cooling panel 10 is detected by the radiant cooling panel inlet temperature sensor 17, and the evaporation temperature of the refrigerant is controlled by the valve opening degree of the radiant cooling panel outlet expansion valve 21, thereby controlling the temperature of the radiant cooling panel 10. The panel temperature is adjusted to match the dew point of the indoor air. This dew point is detected by a dew point sensor installed indoors, and the temperature of the surface of the radiant cooling panel 10 is controlled so that no dew condensation occurs. Thereafter, the refrigerant merges with the refrigerant that has passed through the indoor heat exchanger 3 and is sucked into the compressor 1 again, repeating the cycle. The refrigeration cycle is controlled by detecting the refrigerant outlet temperature of the radiant cooling panel 10 with the radiant cooling panel outlet temperature sensor 18 and the refrigerant evaporation temperature of the radiant cooling panel 10 with the radiant cooling panel inlet temperature sensor 17, and determining the degree of refrigerant superheating. Then, the radiant cooling panel inlet expansion valve 8 is controlled to adjust the degree of superheating of the radiant cooling panel 10. In addition, the refrigerant suction temperature of the compressor is detected by the suction temperature sensor 16, the evaporation temperature of the indoor heat exchanger 3 is detected by the indoor heat exchanger temperature sensor 19, and the degree of refrigerant superheating is determined.
The indoor heat exchanger expansion valve 29 is controlled to adjust the degree of superheating of the refrigerant sucked into the compressor.

The amount of refrigerant is adjusted as follows. The outdoor heat exchanger central temperature sensor 27 detects the condensing temperature, and the outdoor heat exchanger temperature sensor 20 detects the outdoor heat exchanger outlet temperature, and the degree of supercooling is determined from the temperature difference.

Degree of supercooling = condensation temperature - outdoor heat exchanger outlet temperature If the degree of supercooling is large, the radiant heating panel outlet expansion valve 2
5 is fully opened and excess refrigerant is stored in the radiant heating panel 4. At this time, the solenoid valve 22 is fully closed. Further, if the degree of supercooling is small, the solenoid valve 22 is fully opened and the refrigerant staying in the radiant heating panel 4 is released to the indoor heat exchanger 3. At this time, the radiant heating panel outlet expansion valve 25 is fully closed.

As described above, the refrigeration cycle can be operated normally by controlling the radiant heating panel outlet expansion valve 25 and the solenoid valve 22 so as to obtain an appropriate degree of supercooling.

Next, the case of heating will be explained. The indoor heat exchanger expansion valve 29 is fully closed. As shown by the dotted line, the high-temperature, high-pressure refrigerant discharged from the compressor 1 passes through the four-way valve 2, reaches the indoor heat exchanger 3, exchanges heat with the indoor air driven by the indoor fan 13, radiates heat, and condenses. It liquefies and the flow in this direction is stopped by the indoor heat exchanger expansion valve 29, so the solenoid valve 22 is fully opened, and after passing through the solenoid valve 22, it reaches the radiant heating panel 4 and makes the radiant heating panel 4 high temperature. , leading to the radiant heating panel outlet expansion valve 25. The refrigerant becomes a low-pressure gas-liquid two-phase state at the radiant heating panel outlet expansion valve 25 and reaches the outdoor heat exchanger 7. After exchanging heat with outside air driven by the outdoor fan 14 in the outdoor heat exchanger 7 and evaporating it into low-temperature, low-pressure steam, it passes through the four-way valve 2 and is sucked into the compressor 1 again. At this time, the indoor heat exchanger 3 heats the indoor air to heat the room, and the radiant heating panel 4 heats the room by radiation and natural convection.

The refrigeration cycle is controlled by detecting the suction refrigerant temperature of the compressor with the suction temperature sensor 16 and the refrigerant evaporation temperature of the outdoor heat exchanger with the outdoor heat exchanger temperature sensor 20 to determine the degree of refrigerant superheating. Panel outlet expansion valve 25
This is done by controlling the temperature and adjusting the degree of superheating of the refrigerant sucked into the compressor.

The amount of refrigerant is adjusted as follows. The radiant heating panel inlet temperature sensor 23 detects the condensation temperature, and the radiant heating panel outlet temperature sensor 24 detects the radiant heating panel outlet temperature, and the degree of supercooling is determined from the temperature difference.

[0020] Degree of supercooling = condensation temperature (T23) - radiant heating panel outlet temperature (T24) If the degree of supercooling is large, the radiant cooling panel outlet expansion valve 21
is fully opened and excess refrigerant is stored in the radiation cooling panel 10. At this time, the radiant cooling panel inlet expansion valve 28 is fully closed. Furthermore, if the degree of supercooling is small, the radiant cooling panel inlet expansion valve 28 is fully opened, and the refrigerant staying in the radiant cooling panel 10 is released to the outdoor heat exchanger 7. At this time, the radiant cooling panel outlet expansion valve 21 is fully closed.

As described above, the refrigeration cycle can be operated normally by controlling the radiant cooling panel outlet expansion valve 21 and the radiant cooling panel inlet expansion valve 28 to achieve an appropriate degree of supercooling.

As can be seen from the above description, in the air conditioner of this embodiment, the amount of refrigerant can be adjusted without complicating the configuration compared to the air conditioner of the comparative example.

[0023]

[Effects of the Invention] The air conditioner of the present invention is equipped with a radiant cooling panel and a radiant heating panel and is capable of heating and cooling, and has a configuration in which the radiant heating panel is used as a refrigerant reservoir during cooling, and the radiant cooling panel is used as a refrigerant reservoir during heating. Therefore, the amount of refrigerant can be adjusted with a simple configuration so that the degree of subcooling is always appropriate.

[0024] Furthermore, since the degree of supercooling can be controlled to always be appropriate depending on the cooling/heating load, the performance of the refrigeration cycle can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an air conditioner of a comparative example.

[Explanation of symbols]

1: Compressor
2: Four-way valve 3: Indoor heat exchanger
4: Radiant heating panel 7: Outdoor heat exchanger 1
0: Radiant cooling panel 13: Indoor fan 1
4: Outdoor fan 16: Intake temperature sensor
17: Radiant cooling panel inlet temperature sensor 18: Radiant cooling panel outlet temperature sensor 19: Indoor heat exchanger temperature sensor 20: Outdoor heat exchanger temperature sensor 21: Radiant cooling panel outlet expansion valve 22: Solenoid valve 23
:Radiant heating panel inlet temperature sensor 24:Radiant heating panel outlet temperature sensor 25:Radiant heating panel outlet expansion valve
27: Outdoor heat exchanger central temperature sensor 28: Radiant cooling panel inlet expansion valve 29: Indoor heat exchanger expansion valve

Claims (1)

[Claims] [Claim 1] An air conditioner capable of heating and cooling equipped with a radiant cooling panel and a radiant heating panel, the amount of refrigerant being adjusted by using the radiant heating panel as a refrigerant reservoir during cooling and using the radiant cooling panel as a refrigerant reservoir during heating. An air conditioner characterized by being equipped with an adjustment means.