JPH0225641A - Refrigerant natural circulation type heat migrating device - Google Patents

Abstract

PURPOSE:To prevent lowering of cooling capacity even when a difference in a level between an indoor machine and an outdoor machine is high by a method wherein when a refrigerant in a level stabilizer is vaporized and a level is lowered, the level is detected by a level detector, and a control valve increases its opening according to a lowering amount of the level. CONSTITUTION:When a refrigerant in a level stabilizer 7 is vaporized and a level is lowered, the level is detected by a level detector 8. When a signal therefrom is transmitted to a control device 10, a control valve 9 increases its opening according to a decrease amount of the height of the level of a refrigerant in a vaporizer 1. Thus, only a quantity, equivalent to an amount of a vaporized, of refrigerant in an upper refrigerant piping 6A on the liquid side flows through a lower refrigerant piping 6B on the liquid side to the vaporizer 1. The level of a refrigerant in the level stabilizer 7 is raised, and the level is maintained at a given value. Even when a difference in a level between an indoor machine 2 and an outdoor machine 4 is high, a level in the level stabilizer 7 is kept at the same value, and besides since the level stabilizer 7 is situated in the vicinity of an outlet 1B of the vaporizer 1, a pressure in the vaporizer 1 is kept st a low value, and cooling capacity can be prevented from lowering.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a natural refrigerant circulation heat transfer device that utilizes a natural refrigerant circulation cycle.

[Prior Art] Recently, there has been a demand for an energy-saving air conditioner for rooms, such as computer rooms, which have high internal heat generation and are required to strictly clean the air under temperature and humidity conditions. As one of the products that meet this demand, large air conditioners that use a heat pump type air conditioning system and a refrigerant natural circulation heat transfer device that uses low-temperature outside air to transfer heat indoors to the outside are attracting attention. .

The above-mentioned refrigerant natural circulation heat transfer device is also called a thermoshoifon, and has heat exchangers installed indoors and outdoors connected in a ring shape with refrigerant piping, and a low boiling point refrigerant is sealed inside.

As such a refrigerant natural circulation type heat transfer device, for example, one shown in Japanese Utility Model Application Laid-open No. 61-79773 is known (
(Illustrated in Figure 3).

As shown in the figure, the refrigerant natural circulation heat transfer device 101 includes an evaporator 102 provided in an indoor unit 111 on the indoor side, and a condenser 102 disposed at a high place above the evaporator 102 and provided in an outdoor unit 112 on the outdoor side. 103, a gas side refrigerant pipe 104 connecting the outlet 102B of the evaporator 102 and the inlet 103A of the condenser 103, &1 the outlet 103B of the condenser 103 and the evaporator 1
02 inlet 102A.

In the refrigerant natural circulation heat transfer device 101, the refrigerant is
It is heated by the warm indoor air in the evaporator 102,
Boil and evaporate. The indoor air is cooled by the latent heat of vaporization at this time. The evaporated refrigerant becomes a gas and moves up the gas side refrigerant pipe 104, is led to the condenser 103, and is cooled by the cold outside air. The cooled refrigerant is condensed and liquefied, flows down inside the legal refrigerant piping 105, and returns to the evaporator 102 again.

The above refrigerant circulation occurs due to the natural circulation force due to the difference in specific gravity due to the phase change of the refrigerant and the difference in height of the refrigerant liquid level. If the temperature outside the room is lower than the temperature inside the room, this refrigerant circulation occurs without power. Heat inside the room is released outside.

[Problems to be Solved by the Invention] In the refrigerant natural circulation heat transfer device 101 described above, as buildings become taller, the height difference between the indoor unit 111 and the outdoor unit 112, which is generally installed on the rooftop, becomes large. Therefore, the cooling capacity decreases. This is because, as shown in FIG. 4, as the liquid column H in the gas side refrigerant pipe 104 becomes higher, the refrigerant liquid pressure applied to the evaporator 102 in the indoor unit 111 becomes higher. This is because boiling of the refrigerant becomes difficult to occur and the evaporation temperature becomes high.

Even when the height difference between the indoor unit 111 and the outdoor unit 112 is large, in order to obtain a large cooling capacity when the height difference is small,
It is necessary to increase the temperature difference between the condenser 103 and the evaporator 102, that is, the temperature difference between indoors and outdoors, to make it easier to boil the refrigerant in the evaporator 102 and lower the evaporation temperature. Therefore,
In this case, the outdoor air temperature at which cooling can be started using the above-mentioned natural refrigerant circulation type must be lowered, and the operating efficiency of the natural refrigerant circulation type heat transfer device 101 decreases.

Further, even during operation, the evaporation temperature is high, so the heat exchange capacity is reduced, and the cooling efficiency of the entire device is reduced.

The present invention was made in order to solve such conventional problems, and its purpose is to provide natural refrigerant circulation that does not reduce the cooling capacity and has high cooling efficiency even when there is a large height difference between the indoor unit and the outdoor unit. An object of the present invention is to provide a type heat transfer device.

[Means to solve the problem]

In order to achieve the above object, the present invention includes one or more evaporators installed on the indoor side, a condenser installed on the outdoor side and located above the evaporator, and an outlet of the evaporator and a condenser. The gas side refrigerant piping connects the inlet of the refrigerant, and the legal refrigerant piping connects the condenser outlet and the evaporator inlet. In a refrigerant natural circulation heat transfer device that circulates a certain amount of refrigerant and transfers heat from the indoor side to the outdoor side due to the temperature difference between the outdoor side and the indoor side, it is installed near the outlet of the evaporator of the gas side refrigerant piping. A liquid level stabilizer for storing liquid refrigerant, a liquid level detector for detecting the liquid level of the liquid refrigerant in the liquid level stabilizer, and a liquid level detector installed in the middle of legal refrigerant piping to supply liquid refrigerant to the evaporator. A control valve that controls the flow rate, and a control device that controls the opening/closing degree of the control valve to increase as the height decreases when the liquid level of the refrigerant detected by the liquid level detector changes from a predetermined height. It is equipped with the following.

[For production]

In the present invention, when the refrigerant in the liquid level stabilizer evaporates and the liquid level drops, the liquid level is detected by the liquid level detector and the signal is transmitted to the control device. Then, in response to a command from the control device, the degree of opening and closing of the control valve increases in accordance with the amount of decrease in the height of the liquid level. Therefore, the refrigerant in the legal refrigerant piping, which is stopped by the control valve, flows to the evaporator in an amount equal to the amount of evaporated refrigerant, and the liquid level of the refrigerant in the liquid level stabilizer rises, until the liquid level reaches a predetermined height. will be maintained.

〔Example〕

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

FIG. 1 shows a refrigerant natural circulation type heat transfer device according to a first embodiment of the present invention.

In FIG. 1, 1 is an evaporator, which is installed inside an indoor unit 2 on the indoor side. A condenser 3 is located above the evaporator 1 and is installed inside the outdoor unit 4 on the outside of the room. 5 is a gas side refrigerant pipe that connects the outlet IB of the evaporator 1 and the large mouth 3A of the condenser 3. 6 is the source side refrigerant pipe,
The outlet 3B of the condenser 3 and the inlet IA of the evaporator 1 are connected. Evaporator 1. Gas side refrigerant piping 5. Condenser 3. A certain amount of refrigerant circulates between the source-side refrigerant pipes 6.

The source-side refrigerant pipe 6 includes an upper liquid-side refrigerant pipe 6A having a large diameter above a control valve 9, which will be described later, and a lower liquid-side refrigerant pipe 6B having a small diameter below the control valve 9.
It consists of

A liquid level stabilizer 7 is provided near the outlet IB of the evaporator 1 of the gas side refrigerant pipe 5, and contains liquid refrigerant.

A liquid level detector 8 detects the liquid level of the liquid refrigerant in the liquid level stabilizer 7. A control valve 9 is provided in the middle of the source refrigerant pipe 6, and controls the flow rate of liquid refrigerant to the evaporator 1 by controlling its opening/closing degree. Reference numeral 10 denotes a control device that controls the opening/closing degree of the control valve 9 to increase as the height decreases when the liquid level of the refrigerant detected by the liquid level detector 8 changes from a predetermined height.

Next, the operation of this embodiment will be explained.

When the refrigerant in the liquid level stabilizer 7 evaporates and the liquid level drops,
The liquid level is detected by the liquid level detector 8, and the signal is transmitted to the control device 10. In response to a command from the control device 10, the degree of opening and closing of the control valve 9 increases in accordance with the amount of decrease in the height of the refrigerant in the evaporator 1. Therefore, the refrigerant in the upper liquid side refrigerant pipe 6A, which is stopped by the control valve 9, flows to the evaporator 1 through the lower liquid side refrigerant pipe 6B in an amount equal to the amount of evaporated refrigerant.
The liquid level of the refrigerant in the liquid level stabilizer 8 rises, and the liquid level is maintained at a predetermined height.

According to the above configuration, even if the height difference between the indoor unit 2 and the outdoor unit 4 is large, the liquid level in the liquid level stabilizer 7 is maintained at the same height, so the liquid level in the evaporator 1 is maintained at the same level. A liquid pressure is applied at a predetermined liquid level of the refrigerant in the ballast 7. Moreover, since the liquid level stabilizer 7 is installed near the outlet IB of the evaporator 1, the liquid level is at a low position, so the liquid column in the five gas side refrigerant pipes is kept low, and as a result, the evaporator By keeping the pressure inside 1 low, the device can be operated without reducing its cooling capacity. Furthermore, the outdoor air temperature at which cooling can be started by the above-mentioned natural refrigerant circulation type may be high, and the operating efficiency of the natural refrigerant circulation type heat transfer device can be improved.

In addition, if the device stops cooling operation, the liquid level stabilizer 7
Since the liquid level of the refrigerant is maintained at a predetermined level inside the unit, the temperature difference between the indoor and outdoor areas will be very small even when the unit is operated again. Therefore, the utilization efficiency of the device can be improved.

Furthermore, even during operation, the evaporation temperature is lowered, so the heat exchange capacity is increased, and the cooling efficiency of the entire device can be improved.

FIG. 2 shows a refrigerant natural circulation heat transfer device according to a second embodiment of the present invention, in which a condenser 11A in an outdoor unit 11, an evaporator 12A in an indoor unit 12, and an evaporator in an indoor unit 13 are connected. 13A
and the evaporator 14A in the indoor unit 14 are connected to the gas side refrigerant pipe 15. It is connected via source side refrigerant piping 16. Liquid level stabilizers 12B, 13B, 14B and liquid level detectors 12C1 correspond to these evaporators 12A, 13A, 14A, respectively.
13c, 14C, control valve 12D, 13D,
14D, a control device 17 is installed.

The evaporator 12A in the indoor unit 12, the evaporator 13A in the indoor unit 13, and the evaporator 14A in the indoor unit 14 are connected in parallel. Each evaporator 13A.

Condenser 11A is located higher than 14A and 15A.

According to the second embodiment, in addition to the effects of the first embodiment, a plurality of indoor units can be installed for one outdoor unit, and in this case, each evaporator 12A, 13A, 14, 1 :Since the cooling capacity of each indoor unit 12,
There is no need to install 13 and 14 at the same height.

[Effects of the Invention] As described above, according to the refrigerant natural circulation heat transfer device according to the present invention, even if the height difference between the indoor unit and the outdoor unit is large, the liquid level in the liquid level stabilizer remains the same. Because it is kept at a high height,
The evaporator is subjected to liquid pressure at a predetermined liquid level of the refrigerant in the liquid level stabilizer. Moreover, since the liquid level stabilizer is installed near the outlet of the evaporator, the liquid level is at a low position, so the liquid column on the gas side refrigerant piping side is kept low, and as a result, the pressure inside the evaporator is reduced. The device can be operated without reducing the cooling capacity. Furthermore, the outdoor air temperature at which cooling can be started by the above-mentioned natural refrigerant circulation type may be high, and the operating efficiency of the natural refrigerant circulation type heat transfer device can be improved.

In addition, when the equipment stops cooling operation, the refrigerant level is maintained at a predetermined level in the liquid level stabilizer, so even when the equipment starts operating again, the temperature difference between indoor and outdoor is very small. good.

Therefore, the utilization efficiency of the device can be improved.

Furthermore, even during operation, the evaporation temperature is lowered, so the heat exchange capacity is increased, and the cooling efficiency of the entire device can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a natural refrigerant circulation type heat transfer device according to a first embodiment of the present invention. FIG. 2 is a block diagram of a natural refrigerant circulation type heat transfer device according to a second embodiment of the present invention. FIG. 3 is a configuration diagram of a conventional refrigerant natural circulation type heat transfer device. FIG. 4 is an explanatory diagram of the problems of the natural refrigerant circulation type heat transfer device. [Explanation of symbols of main parts] 1...Evaporator IA...Inlet 1B...Outlet 3...Condenser 3A...Inlet 3B...Outlet 5...Gas side refrigerant piping 6 ...Legal refrigerant piping 7...Liquid level stabilizer 8...Liquid level detector 9...Control valve 10...Control device. Figure 1 1A (Entrance) Figure 1

Claims (1)

[Claims] (1) one or more evaporators installed on the indoor side; a condenser installed on the outdoor side and located above the evaporator;
The evaporator, the gas side refrigerant piping, and the condenser are equipped with a gas side refrigerant piping that connects the evaporator outlet and the condenser inlet, and a liquid side refrigerant piping that connects the condenser outlet and the evaporator inlet. , in a refrigerant natural circulation heat transfer device that circulates a certain amount of refrigerant between the liquid side refrigerant piping and transfers heat from the indoor side to the outdoor side due to the temperature difference between the outdoor side and the indoor side, the gas side refrigerant piping A liquid level stabilizer installed near the outlet of the evaporator to contain liquid refrigerant, a liquid level detector that detects the liquid level of the liquid refrigerant in the liquid level stabilizer, and a liquid level detector installed in the middle of the liquid side refrigerant piping. A control valve that controls the flow rate of liquid refrigerant to the evaporator, and when the liquid level of the refrigerant detected by a liquid level detector changes from a predetermined height, the opening/closing degree of the control valve is adjusted according to the decrease in height. 1. A refrigerant natural circulation heat transfer device, comprising: a control device for controlling the temperature to increase.