JPH0810066B2 - Building air conditioning system - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a building air conditioning system, and more particularly to a building air conditioning system in which heat is transferred by a gravity heat pipe.

[Prior art]

Generally, in a building air conditioning system, water is usually used in the form of steam, hot water, or cold water as a heat medium that circulates between the heat source side and each air conditioning unit and contributes to heat transfer. By the way, there are cases where this air conditioning unit is installed on the side of the living room, which is the room to be air conditioned, but such an arrangement is not preferred because there is a risk of water leakage in the living room.
Therefore, in recent building air conditioning systems, attention has been paid to a system in which a refrigerant such as CFC is used as a heat medium instead of water and the refrigerant is directly led from the heat source side to the heat exchanger of each air conditioning unit. As one of such building air conditioning systems, the applicant of the present application has already applied for an invention relating to a building air conditioning system using a gravity type heat pipe (Japanese Patent Application No. 61-264309). In a building air conditioning system using this gravity type heat pipe, the refrigerant circulation system between the heat source side and each air conditioning unit is composed of a natural circulation system without a compressor. That is, according to the present invention, the first gravity heat pipe for cooling and the second gravity heat pipe for heating are configured, and each air conditioning unit is installed in the building having the air-conditioned room. In the unit, a condensing part of the second gravity type heat pipe as a heat exchanger for heating and a vaporizing part of the first gravity type heat pipe as a heat exchanger for cooling are provided. On the other hand, the condensing part of the first gravity type heat pipe is located higher than each air conditioning unit corresponding to the evaporating part as a heat exchanger for cooling, and the heat exchanging part for heating is located lower than each air conditioning unit. The evaporator of the second gravity heat pipe is provided corresponding to the condenser as the container. Refrigerant is enclosed in each gravity heat pipe, and the refrigerant naturally circulates in each heat pipe while undergoing heat exchange and vapor-liquid phase change in each evaporator and condenser, thereby performing heat transfer. Be done.

[Problems to be Solved by the Invention]

By the way, in the air conditioning system having the heat transfer system as described above, when controlling the heating capacity and the cooling capacity in each operation mode in response to the heat load in each room to be air-conditioned, each refrigerant natural The circulation flow rate of the refrigerant in the circulation system will be controlled. However, if the flow rate control of the refrigerant is actually performed, various problems occur, for example, when the installation height position of each air conditioning unit is different, the head pressure of the refrigerant liquid acting on each air conditioning unit is different, Equal heat exchange conditions cannot be satisfied in each air conditioning unit. Also,
If the heat load of each air-conditioned room is different, it is necessary to adjust and control the cooling capacity or heating capacity according to the heat load of each air-conditioned room. Since the air-conditioning unit with a larger load has a larger amount of heat exchange, the amount of heat generated by the refrigerant also increases, and therefore the resistance in the refrigerant gas pipe also increases. That is, since the resistance increases in a system that requires a larger flow rate of the refrigerant, in actuality, a large amount of refrigerant is supplied to the system that does not require a large load and does not require a large flow rate of the refrigerant. . The present invention has been devised in view of the above problems to effectively solve these problems. Therefore, it is an object of the present invention to provide a building air conditioning system capable of controlling its capacity in more concretely realizing the building air conditioning system that carries heat by using a gravity type heat pipe.

[Means for solving problems]

The building air conditioning system according to the present invention has the following configuration in order to solve the problems of the conventional technology and achieve the object. That is, an air conditioning unit having a first condenser as a heat exchanger for heating indoor air and a first evaporator as a heat exchanger for cooling indoor air is provided, and the air conditioning unit is installed below the air conditioning unit. No. 1 condenser is provided with a second evaporator as a heat exchanger for a heat source, is installed above the air conditioning unit, and is a second condenser as a heat exchanger for a cold heat source corresponding to the first evaporator. And a first condenser and a second evaporator, and a first condenser and a second condenser are connected by a refrigerant liquid pipe and a refrigerant gas pipe, respectively, and a natural refrigerant circulation to each of them. In a building air conditioning system that forms a system, a difference between the set target value of room temperature and the temperature of the return air to the air conditioning unit is set at each refrigerant inlet of the first condenser and the first evaporator. In order to reduce, each opening cooperates with each other Flow rate control valves to be controlled are respectively provided, and the first evaporator has a liquid level detecting means for detecting that the refrigerant liquid level in the evaporator is at a predetermined height position and outputting a detection signal thereof. Of the flow rate control valves, the flow rate control valve provided at the refrigerant inlet of the first evaporator is configured to be closed by a detection signal from the liquid level detection means.

[Action]

According to the building air-conditioning system of the present invention, the heating operation is performed by the refrigerant natural circulation system including the first condenser, the second evaporator, and the refrigerant liquid pipe and the refrigerant gas pipe connecting the first condenser and the second evaporator. On the other hand, the cooling operation is performed by the refrigerant natural circulation system including the first evaporator, the second condenser, and the refrigerant liquid pipe and the refrigerant gas pipe that connect them. The flow rate of the refrigerant supplied to the first condenser and the first evaporator in the air conditioning unit is controlled by the flow rate control valve provided at each refrigerant inlet. The control is such that the valve opening is adjusted in relation to each other so that the air temperature in the air-conditioned room that returns to the air-conditioning unit approaches the target value of room temperature set in the air-conditioned room. When the temperature is higher than the target value, the flow control valve of the first evaporator is opened to perform the cooling operation. Alternatively, the opening is increased. Therefore, the flow control valve of the first condenser is fully closed. When the recirculated air temperature is lower than the target value, the flow control valve of the first condenser is opened to perform the heating operation,
Alternatively, the opening is increased. Therefore, the flow control valve of the first evaporator is fully closed. In this way, the valve opening degree is controlled and the refrigerant supply amount is controlled according to the load in each air conditioning unit, so it is possible to suppress uneven flow of the refrigerant due to the amount of heat exchange, that is, the amount of evaporation. The opening control of each flow control valve may be binary control of only opening and closing, or the opening may be controlled stepwise or steplessly. The flow rate control valve of the first evaporator is also controlled so that the liquid level of the refrigerant filled in the first evaporator does not exceed a predetermined height. That is, when the flow rate control valve of the first evaporator is opened and the refrigerant liquid flows into this evaporator, the refrigerant liquid level in the evaporator tends to become equal to the liquid level in the refrigerant liquid pipe, and the maximum of the evaporator is reached. It tries to flow into a position higher than the upper part,
The liquid level detecting means provided in the first evaporator monitors the refrigerant liquid level in the first evaporator, and the liquid level detecting means outputs a liquid level for outputting a detection signal for closing the flow control valve, For example, if the liquid level is set to the highest heat exchange efficiency, the flow control valve is closed when the inflowing refrigerant reaches the liquid level. Therefore, the refrigerant supply amount to the first evaporator is controlled on the basis of the difference between the reflux air temperature and the room temperature target value, and the liquid level in the first evaporator is controlled so as not to exceed the predetermined height. Regulated. Furthermore, it is also possible to control each of the flow rate control valves together with the amount of air passing through the first condenser and the first evaporator.

【The invention's effect】

As is clear from the above description, according to the present invention, the following excellent effects are exhibited. That is, in practically implementing a building air-conditioning system that uses a gravity heat pipe to transfer heat, it is possible to control its capacity according to the load of the air-conditioned room. In particular, even if the height positions of the air conditioning units are different from each other, it is possible to secure an appropriate refrigerant liquid level in each of the first evaporators and prevent the refrigerant from flowing unevenly with respect to the load.

【Example】

A preferred embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram showing a building air conditioning system according to the present invention. In this system, the position of each component is specified with respect to the height position. That is, each air conditioning unit 1 is installed in each air-conditioned room in the building.
Whereas the first condenser 2 is provided as a heat exchanger for heating operation, that is, indoor air heating, and the first evaporator 3 is provided as a heat exchanger for cooling operation, that is, indoor air cooling. The second evaporator 5 that constitutes the heating refrigerant circulation system together with the first condenser 2 is provided at a position lower than the air conditioning unit 1, while the first evaporator 3 constitutes the cooling refrigerant circulation system together with the first evaporator 3. The two condensers 4 are provided at a position higher than the air conditioning unit 1, and in each refrigerant circulation system, the evaporator and the condenser are connected by refrigerant liquid pipes 6 and 7 and refrigerant gas pipes 8 and 9. The second condenser 4 is provided, for example, in an ice heat storage tank 10 as a cold heat source side installed on the roof of a building, and the second evaporator 5 is hot water heat storage as a hot heat source side installed in the underground of the building. It is provided in the tank 11. A heat source device for storing or storing heat in the heat storage tanks 10 and 11 is a heat pump chiller 14 having an ice maker 12 and a water heater 13 built therein. A slurry pump 15 is interposed between the ice heat storage tank 10 and the ice maker 12 to pump the ice produced by the ice maker 12 to the ice heat storage tub 10. In addition, between the hot water heat storage tank 11 and the water heater 13, a water heater 13
Hot water pump 16 for sending hot water made by
Is interposed. In the figure, 17 is an accumulator, 18
Is an expansion valve, 19 is an air heat exchanger, and 20 is a compressor. Each air conditioning unit 1 includes a first condenser 2 and a first condenser 2 described above.
The blower 21 is another main configuration of the evaporator 3, and this blower
And a thermistor 22 for detecting the temperature of the recirculated room air sucked into 21. In addition, at the refrigerant liquid inlet of the first evaporator 3 and the refrigerant outlet of the first condenser 2, respectively,
Flow rate control valves 23 and 24 are provided, and in particular, a liquid level detection sensor 26 as liquid position detection means is attached to the upper end of the first evaporator 3. Thermistor 22 and liquid level sensor 26
From, the respective detection signals are output and input to the controller 25. The controller 25 performs arithmetic processing based on these signals to calculate the opening of each of the flow rate control valves 23 and 24 and the rotation speed of the blower 21, and to calculate the flow rate control valves 23 and 24 and the blower 21 respectively. An operation command signal for instructing the opening degree and the rotation speed is output. FIG. 2 shows the first condenser 2 and the first condenser 2 in this embodiment.
It is a graph figure which shows the control state regarding the recirculation room air temperature about each valve opening of the evaporator 3, and the rotation speed of the air blower 21. In the figure, the upper stage is the flow control valve 24 of the first condenser 2.
Of the flow rate control valve 23 of the first evaporator 3 is shown in the middle stage, and the rotational speed of the blower 21 is shown in the lower stage. In the present embodiment, the set room temperature target value is set as a set point SP, and roughly speaking, when the recirculation room air temperature becomes lower than the set point, heating operation is performed, and when it becomes higher, cooling operation is performed. Controlled to do. First, regarding the valve opening, in this embodiment, each flow control valve 23, 2
4 is a binary control of fully open or fully closed only by turning on / off, and the set room temperature target value is set point SP,
When the air temperature in the recirculation chamber is higher than the set point, the flow control valve 24 of the first condenser 2 is closed and the flow control valve 23 of the first evaporator 3 is opened to perform the cooling operation. On the contrary, when the air temperature in the recirculation room is lower than the set point, the flow rate control valve 24 of the first condenser 2 is operated to perform the heating operation.
Is opened and the flow control valve 23 of the first evaporator 3 is closed.
That is, the heating operation and the cooling operation are switched around the set point. This switching has a range between the temperature difference in which the flow control valves 23 and 24 are opened and the temperature difference in which they are closed, and when switching from cooling operation to heating operation, the solid line in the graph diagram As shown, the flow control valve 23 of the first evaporator 3 is closed when the temperature of the recirculation chamber air is slightly below the set point, and when the temperature of the recirculation chamber air is further decreased, the flow control of the first condenser 2 is controlled. Valve 24 is opened. Further, when the heating operation is switched to the cooling operation, the flow rate control valve 24 of the first condenser 2 is set when the recirculating room air temperature slightly exceeds the set point, as indicated by the two-dot chain line in the graph. Is closed and the flow control valve 23 of the first evaporator 3 is opened when the temperature of the air in the reflux chamber further rises. However, even if the air temperature of the recirculation chamber is such that the flow control valve 23 of the first evaporator 3 is opened during the cooling operation, the refrigerant in the first evaporator 3 has a predetermined high temperature so as to fill the inside thereof. When the liquid level is high, a detection signal is output from the liquid level detection sensor 26, and the flow rate control valve 23 is closed. Next, regarding the number of revolutions of the blower, in this embodiment, low, medium,
It is controlled in three stages of high, and in both heating operation and cooling operation, the rotational speed is increased as the recirculated room air temperature departs from the set point SP. Further, as indicated by a solid line when the cooling operation is switched to the heating operation and as indicated by a two-dot chain line when the heating operation is switched to the cooling operation, the rotation speed is lower than that when the rotation speed is switched from the low rotation speed to the low rotation speed. When switching to a higher one, the temperature of the recirculating air chamber is set to be far from the set point,
In particular, when the rotation speed is switched from low to middle, the flow control valve 24 of the first condenser 2 is opened and the flow control valve of the first evaporator 3 is opened in each of the heating operation and the cooling operation. It is set at the same time as when 23 is opened. Further, the rotation speed of the blower 21 is constant, and as shown in the graph of FIG. 3, only the opening degree of the flow control valves 23 and 24 of the first condenser 2 and the first evaporator 3 is changed. Proportional control may be performed such that the valve opening degree increases as the air temperature moves away from the set point SP. In the figure, the solid line indicates the valve opening of the flow control valve 23, and the broken line indicates the valve opening of the flow control valve 24. Although the liquid level detection sensor 26 is used as the liquid level detection means in the above-described embodiment, for example, a temperature sensor (not shown) is attached to each of the refrigerant inlet and the refrigerant outlet of the first evaporator 3. It is also possible to detect the refrigerant liquid level in the first evaporator 3 based on the temperatures detected by both temperature sensors. That is, since the refrigerant that has been heat-exchanged and evaporated in the first evaporator 3 is in a superheated state to some extent, if the refrigerant liquid level in the first evaporator 3 is low and the refrigerant is attached to the refrigerant inlet port. Even if the temperature sensor is immersed, if the coolant level does not reach the height of the temperature sensor attached to the coolant outlet, the temperature sensor at the outlet will be higher than the temperature sensor at the inlet. The temperature will be measured. On the contrary, in a state where the refrigerant liquid level in the first evaporator 3 is sufficiently high and both temperature sensors attached to the inflow port and the outflow port are immersed, both temperature sensors should measure the same temperature. become. Therefore, the refrigerant liquid level in the first evaporator 3 can be detected by comparing the measured values of both temperature sensors, and it can be used as a liquid level detecting means similar to the above-described liquid level detecting sensor 26. As described above, if the valve opening degree is controlled based on the difference between the recirculation room air temperature and the room temperature target value, the inside of the refrigerant circulation system depends on the heat exchange amount, that is, the evaporation amount in the first evaporator 3. Of the air unit 1 requiring the supply of the refrigerant because the resistance of the refrigerant is controlled not by the resistance of the refrigerant fluctuating but by fluctuating the resistance depending on the opening degree of the flow control valves 23, 24. The required amount of refrigerant can be supplied to. In addition, even if the installation height position of each air conditioning unit 1 is different,
Since the upper limit of the liquid level of the refrigerant filled in the first evaporator 3 in each air conditioning unit 1 is controlled by the liquid level detection sensor 26 and the flow control valve 23, the air conditioning unit installed in the low position is installed in the high position. The appropriate refrigerant liquid level can be obtained in each air conditioning unit 1 without being affected by the air conditioning unit. It is also possible to perform dehumidification operation by performing supercooling dehumidification in the first evaporator 3 and using it as a reheater of the first condenser 2. In this case, both flow control valves 23, 24 are opened respectively.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a building air conditioning system according to the present invention. FIG. 2 shows an example of control relating to the air temperature in the recirculation chamber with respect to the valve opening degree of each of the first condenser and the first evaporator and the rotation speed of the blower in one embodiment of the building air conditioning system according to the present invention. It is a graph figure which shows an Example. FIG. 3 is a graph showing another embodiment of the control relating to the temperature of the recirculated indoor air for the valve openings of the first condenser and the first evaporator in the embodiment of the building air conditioning system according to the present invention. is there. 1 ... Air conditioning unit, 2 ... 1st condenser, 3 ... 1st evaporator,
4 ... 2nd condenser, 5 ... 2nd evaporator, 6,7 ... Refrigerant liquid pipe, 8,9
... Refrigerant gas pipe, 10 ... Ice heat storage tank, 11 ... Hot water heat storage tank, 12 ... Ice maker, 13 ... Water heater, 14 ... Heat pump chiller, 15 ... Slurry pump, 16 ... Hot water pump, 17 ... Accumulator, 18
... expansion valve, 19 ... air heat exchanger, 20 ... compressor, 21 ... blower, 22 ... thermistor, 23,24 ... flow control valve, 25 ... controller, 26 ... liquid level detection sensor as liquid level detection means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadahiro Fukunaga 4-27, Honmachi, Higashi-ku, Osaka City, Osaka Prefecture Takenaka Corporation (72) Inventor, Yasutoshi Yoshida, Okawa-cho, Higashi-ku, Osaka, Osaka Building Shinko Industry Co., Ltd. (72) Inventor Setsuo Kaneda, 1 Okawa-cho, Higashi-ku, Osaka City, Osaka Prefecture Nichichiyodo Yabashi Building Shinko Industry Co., Ltd. (56) Reference Japanese Patent Laid-Open No. 1-3447 (JP, A) ) JP-A-63-118546 (JP, A)

Claims (2)

[Claims] 1. An air conditioning unit (1) having a first condenser (2) as a heat exchanger for heating indoor air and a first evaporator (3) as a heat exchanger for cooling indoor air, A second evaporator (5), which is installed below the air conditioning unit (1) and serves as a heat exchanger for a heat source corresponding to the first condenser (2), is provided more than the air conditioning unit (1). A second condenser (4) installed above and serving as a heat exchanger for a cold heat source corresponding to the first evaporator (3) is provided, and the first condenser (2) and the second evaporator (5) ), And the first evaporator (3) and the second condenser (4),
The first condenser (2) and the first condenser (2) and the first condenser (2) are constructed by connecting a refrigerant liquid pipe (6, 7) and a refrigerant gas pipe (8, 9) to each other to form a refrigerant natural circulation system. In order to reduce the difference between the set target value of the room temperature and the temperature of the recirculated air to the air conditioning unit (1), the opening of each of the refrigerant inlets of the evaporator (3) cooperates with each other. Flow rate control valves (23 and 24) to be controlled are respectively provided, and the first evaporator (3) detects that the refrigerant liquid level in the evaporator (3) is at a predetermined height position. The liquid level detection means (26) for outputting the detection signal is provided, and the flow rate control valve (23) provided at the refrigerant inlet of the first evaporator (3) of the flow rate control valves is the liquid level detection means. A building air conditioning system characterized by being closed by a detection signal from (26). 2. The air flow rate of the air conditioning unit (1) is controlled by the difference between the set target value of room temperature and the temperature of the recirculated air to the air conditioning unit (1). The building air-conditioning system according to item.