JP2551978B2 - Evaporation control structure in refrigeration cycle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a condenser part for cooling and liquefying a refrigerant gas, and an evaporative evaporation of the refrigerant liquid for cooling a building or the like and freezing in an ice making machine. The present invention relates to an evaporation control structure in a refrigerating cycle, which includes an evaporation unit for controlling the flow rate and a flow rate control valve for adjusting the flow rate of the refrigerant liquid liquefied in the condensation unit before being supplied to the evaporation unit.

<Prior Art> In the refrigeration cycle as described above, when the refrigerant liquid is evaporated in the evaporator, the refrigerant and the liquid are mixed in the heat exchange passage of the evaporator in terms of heat exchange efficiency. It is preferable to perform heat exchange in a so-called liquid-filled state in which the filled wet steam is filled.

Therefore, conventionally, the following configuration has been adopted.

A. First conventional example This is called a liquid level sensing method. It is constructed such that a communicating pipe is connected to the evaporator that constitutes the evaporating section and the liquid level in the communicating pipe is sensed by a level sensor. On the other hand, a flow rate control valve for adjusting the supply amount of the coolant liquid is provided in the refrigerant liquid supply line to the evaporator, and the flow rate control valve is provided so that the liquid level sensed by the level sensor is maintained at a set level or higher. It operates automatically and fills the entire evaporator with moist steam.

B. Second conventional example In what is called an ejector system, an accumulator is connected in communication with the outlet side of the evaporator, and the accumulator is connected in communication with the inlet side of the evaporator, so that the evaporator is full of liquid. The refrigerant liquid from there is made to flow to an accumulator, the refrigerant liquid and the refrigerant gas are separated in the accumulator, and the refrigerant liquid is returned to the evaporator while taking out the refrigerant gas from the accumulator.
See 58-7902).

C. Third conventional example This is called superheat control, and in addition to the part that performs heat exchange in a full liquid state in the evaporator, the heat exchange heat for superheat is taken out as dry vapor that is completely saturated gas. Is equipped with minutes.

<Problems to be Solved by the Invention> However, each of the conventional configurations has the following drawbacks.

a. Disadvantages of the first conventional example When the liquid level in the evaporator fluctuates instantaneously, such as at start-up, the flow control valve's followability is poor and refrigerant liquid back occurs, causing refrigerant circulation. There was a drawback that hindered.

b. Disadvantages of the second conventional example If a full saturated gas is to be taken out by separating the refrigerant liquid and the refrigerant gas in the accumulator irrespective of the load fluctuation in the evaporator, a large-sized accumulator is required, and the refrigerant is charged. There is a drawback that the amount increases and the efficiency of the refrigeration cycle decreases.

c. Disadvantages of the third conventional example Since the evaporator has a larger size because the evaporator has a heat exchange portion for superheat degree, the refrigerant charging amount is increased and the refrigeration cycle efficiency is reduced as in the second conventional example. There was a drawback to

The present invention has been made in view of such circumstances, and it is possible to satisfactorily take out a completely saturated gas while enlarging the evaporator and performing heat exchange in a full liquid state in the evaporator. The purpose is to do so.

<Means for Solving the Problems> In order to achieve such an object, the present invention provides a condensing part for cooling and liquefying a refrigerant gas, an evaporating part for evaporating and evaporating the refrigerant liquid, and a pre-supplying part to the evaporating part. In a refrigeration cycle equipped with a flow rate control valve that regulates the flow rate of the liquefied refrigerant liquid in the condenser part, a pipe that is connected to the outlet of the evaporation part is provided with a trap for collecting the mixed refrigerant liquid, and the evaporation is performed. Over the outlet side of the section and the downstream side of the trap, a bypass pipe for extracting a part of the refrigerant gas is connected in communication with the bypass pipe, and heating means for heating the taken out refrigerant gas,
A temperature sensor for detecting the temperature of the refrigerant gas after being heated by the heating means is additionally provided, and the flow rate is increased in such a state that the higher the sensed temperature is, the larger the opening is so that the temperature sensed by the temperature sensor is maintained within the set temperature range. An opening adjustment mechanism for automatically adjusting the opening of the control valve is provided and configured.

<Operation> According to the configuration of the evaporation control structure in the refrigeration cycle of the present invention, the evaporation unit is set by setting the temperature range in which the fully saturated gas is obtained with the heating by the heating means as the set temperature range. Then, while the refrigerant is filled in a wet vapor state, a trap prevents the refrigerant liquid from being taken out, while heating a part of the refrigerant gas taken out to the bypass pipe, the heat of the heated high-temperature refrigerant gas Heats the moist steam flowing through the trap by
A completely saturated refrigerant gas can be obtained.

<Example> Next, the example of the present invention is described in detail based on a drawing.

<First Embodiment> FIG. 1 is an overall configuration diagram of a refrigerating cycle, in which a refrigerant liquid pipe 2 and a refrigerant gas pipe 3 are connected in communication with a condenser 1 as a condenser for cooling and liquefying a refrigerant gas. Liquid header 4 provided on each floor of a building such as a building in refrigerant liquid pipe 2.
Are connected to each other, while the gas headers 5 provided on each floor are connected to the refrigerant gas pipe 3.

On each floor, an air conditioning indoor unit 8 including a cooling coil 6 as an evaporation unit and a blower fan 7 is installed.
Cooling coil 6 ..., liquid header 4 and gas header 5
Are connected in communication with each other, and the refrigerant is circulated and flowed over the condenser 1 and the air-conditioning indoor unit 8 ... Each cooling coil 6, and the refrigeration cycle is configured so that each room in the building can be cooled. .

In the drawing, 9 ... Show main valves for the respective floors, and 10 ... Show flow control valves for the respective cooling coils 6.

Further, 11 indicates an ice heat storage tank, and this ice heat storage tank 11 is connected in communication with the ice maker 12, and water is supplied from the ice heat storage tank 11 to the ice maker 12 by the pump 13 and at the same time the fine ice maker 12 made It is configured to return ice to the ice heat storage tank 11.

Further, the cooling pipe 14 in the condenser 1 and the ice heat storage tank 11 are connected to each other via a pump 15, and the cooling water obtained in the ice heat storage tank 11 is supplied to the condenser 1. There is.

A liquid receiver 16 for gas-liquid separation is provided below the condenser 1 in the refrigerant liquid pipe 2.

The refrigerant gas pipe 3 which is connected to the outlet side of the cooling coil 6 and is arranged in an upward slope so as to be positioned higher on the downstream side is mixed with the refrigerant gas pipe 3 as shown in the detailed configuration diagram of FIG. A trap 17 for collecting the collected refrigerant liquid is provided, and the cooling coil 6 is slanted so as to be positioned lower toward the trap 17 side across the downstream side of the trap 17 and the outlet side of the cooling coil 6. A bypass pipe 18 for extracting a part of the refrigerant gas from is connected in communication.

Further, a gas-liquid separator 17a is attached to the lower part of the trap 17, and a liquid return pipe 17b is connected in communication between the gas-liquid separator 17a and the inlet side of the cooling coil 6, and the trap 1
The liquid accumulated in 7 is returned to the cooling coil 6 side.

A pilot heater 19 as a heating means is attached to the bypass pipe 18 to heat the refrigerant gas taken out into the bypass pipe 18.

In the bypass pipe 18, the pilot heater 19
A temperature sensing cylinder 20 as a temperature sensor is attached at a position downstream of the temperature sensing cylinder 20. The temperature sensing cylinder 20 and the flow rate control valve 10 are configured to sense the temperature of the refrigerant gas heated by the pilot heater 19. And are connected for communication via a communication pipe 20a.

The refrigerant gas pipe 3 and the flow rate control valve 10 are connected to each other via a pressure equalizing pipe 21 on the downstream side of the temperature sensing cylinder 20.

As shown in the longitudinal sectional view of FIG. 3, the flow rate control valve 10 has a valve body 23 slidably mounted on a valve box 22, and a diaphragm 25 is integrally connected to a valve rod 24 of the valve body 23. It is configured.

In the valve rod 24, the pressure equalizing pipe 21 is provided in the space on the compression coil spring 26 side for urging the valve body 23 so as to be displaced toward the closing side.
Is connected in communication, and the communication pipe 20a of the temperature-sensitive tube 20 is connected in communication with the space on the opposite side thereof, and the internal pressure changes due to the change in internal pressure due to the temperature sensing of the refrigerant gas by the temperature-sensitive tube 20. When the spring pressure of the compression coil spring 26 and the pressure of the refrigerant gas transmitted through the pressure equalizing pipe 21 become larger than the sum, the valve body 23 is displaced to the open side, and the temperature of the refrigerant gas is changed from that state. The temperature rises 20
The opening degree of the valve body 23 is automatically adjusted so that the opening degree of the valve body 23 becomes large as the internal pressure of the temperature rises, so that the opening degree adjusting mechanism keeps the temperature sensed by the temperature sensing cylinder 20 within the set temperature range. Is configured.

As the set temperature range of the temperature sensing cylinder 20, not only the refrigerant gas heated by the pilot heater 19 but also the refrigerant gas mixed with the heated refrigerant gas and taken out to the refrigerant gas pipe 3 is completely saturated gas. The temperature range is set to a reasonable level.

With the above configuration, the cooling coil 6 causes heat exchange in a wet steam state, and even when the heat is taken out from the cooling coil 6, when the dryness is 100%, for example, it is about 85 to 90%, and the bypass pipe. By mixing with the high temperature refrigerant gas from 18, the completely saturated gas having a dryness of 100% can be taken out to the refrigerant gas pipe 3.

 In the figure, 27 indicates a superheat adjusting screw.

A refrigerant liquid pipe 2 is connected to an intermediate portion of the pressure equalizing pipe 21 via a three-way solenoid valve 28, and when an abnormality such as a refrigerant gas leak occurs, the refrigerant liquid is supplied to the flow control valve 10.
The flow rate control valve 10 is closed so that the leakage amount of the refrigerant gas is minimized.

<Second Embodiment> FIG. 4 is a block diagram showing the details of the essential parts of the second embodiment. In the second embodiment, a double-tube heat exchanger 29 used in an ice maker or the like is used as an evaporating unit, and a liquid to be cooled such as water or brine flows in the inner pipe 29a,
The refrigerant decompressed by the flow rate control valve 10 is configured to pass through the outer tube 29b in a wet vapor state.

The other structure is the same as that of the first embodiment, and the same numbers are given and the description thereof is omitted.

In the first and second embodiments described above, the temperature sensing cylinder 20 is used as the temperature sensor, and the opening of the flow rate control valve 10 is directly adjusted by utilizing the internal pressure change accompanying the change in the sensed temperature. However, for example, as a temperature sensor, while using a thermistor or a thermocouple, the measured temperature is input to a microcomputer, and the opening degree of the flow rate control valve 10 corresponding to the measured temperature is configured to be calculated. On the other hand, an electronic type may be used as the flow rate control valve 10, and the calculated opening may be automatically obtained by the drive output from the microcomputer.

The refrigeration cycle of the above embodiment, by vaporization and liquefaction of the refrigerant, is configured to flow the refrigerant by natural circulation, it can be applied to a refrigeration cycle having a compression step and an expansion step, in that case, the flow rate An expansion valve may be used as a control valve, and the above evaporation control may be performed by adjusting the opening degree of the expansion valve.

<Effect of the Invention> According to the present invention, a bypass pipe and a trap are added, and a heating means and a temperature sensor are provided in the bypass pipe, so that the evaporator is not wet and the refrigerant is wet without vaporizing the evaporator. The refrigerant gas in a fully saturated state can be obtained while it is being filled with the refrigerant, so that the heat exchange efficiency in the evaporator can be improved, and the trap can prevent the refrigerant liquid from backing up. Since the heat exchange part for temperature is not added, it is possible to avoid hindering the efficiency of the refrigeration cycle because it is not necessary to increase the refrigerant charge amount. Now it is possible to construct a stable refrigeration cycle that can be obtained.

[Brief description of drawings]

The drawings show an embodiment of an evaporation control structure in a refrigeration cycle according to the present invention, FIG. 1 is an overall configuration diagram of the refrigeration cycle, and FIG. 2 is a configuration diagram showing details of essential parts of the first embodiment, 3 is a longitudinal sectional view of the flow rate control valve, and FIG. 4 is
It is a block diagram which shows the detail of the principal part of 2nd Example. 1 ... Condenser as condensing part 6 ... Cooling coil as evaporating part 10 ... Flow control valve 17 ... Trap 18 ... Bypass piping 19 ... Pilot heater as heating means 20 ... As temperature sensor Temperature-sensitive tube 29 …… Double-tube heat exchanger as evaporation unit

Claims (1)

(57) [Claims] 1. A condenser part for cooling and liquefying a refrigerant gas, an evaporating part for evaporating and evaporating a refrigerant liquid, and a flow rate control valve for adjusting a flow rate of the refrigerant liquid liquefied by the condensing part before being supplied to the evaporating part. A refrigeration cycle comprising: a pipe connected to the outlet of the evaporation unit, a trap for collecting the mixed refrigerant liquid is provided, and the outlet side of the evaporation unit and the downstream side portion of the trap are provided. , Connecting a bypass pipe for extracting a part of the refrigerant gas, and a heating means for heating the taken-out refrigerant gas to the bypass pipe,
A temperature sensor for sensing the temperature of the refrigerant gas after heating by the heating means is additionally provided, and in order that the temperature sensed by the temperature sensor is maintained within a set temperature range, the higher the sensed temperature, the larger the opening degree. An evaporation control structure in a refrigerating cycle, comprising an opening adjustment mechanism for automatically adjusting the opening of the flow rate control valve.