JPH028656A - Evaporation control structure in freezing cycle - Google Patents

Abstract

PURPOSE:To improve a heat exchanging efficiency at an evaporation part and prevent a back flow of coolant liquid by a method wherein an outlet side of a cooling coil is provided with a bypassing pipe and a strap and the bypassing pipe is provided with a heating means and a temperature sensor. CONSTITUTION:A coolant gas pipe 3 having an upward gradient connected to an outlet port of a cooling coil 6 is provided with a trap 17 and a bypassing pipe 18 having a downward gradient at a downstream side of the trap and an outlet port of the cooling coil 6. Coolant liquid mixed in coolant gas fed from the cooling coil 6 is collected by the trap 17 and then the coolant liquid is returned to the cooling coil 6 through a gas-liquid separating device 17a and a liquid returning pipe 17b. Coolant gas passing through a bypassing passage 18 is heated by a pilot heater 19 so as to take out a complete saturated gas with a degree of dryness of 100% from the coolant gas pipe 3. A temperature of the heated coolant gas is detected by a thermo-sensing cylinder 20. As an inner pressure (a temperature) is increased, the opening of a flow rate adjusting valve 10 is increased and the temperature is substantially kept at its predetermined value. In this way, it is possible to increase a heat exchanging operation at an evaporating part and further to prevent a back-flow of the coolant liquid.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a condensing section that cools and liquefies refrigerant gas in order to cool buildings such as buildings, freeze ice machines, etc.
A tea generator part that evaporates the refrigerant liquid, and a flow rate adjustment n1 that adjusts the flow rate of the refrigerant liquid liquefied in the condensation part before being supplied to the evaporation part.
This article relates to a nuclear power plant control structure in a refrigeration cycle with a valve size of 0R.

<Conventional Technique I> In the above-mentioned refrigeration cycle, when the refrigerant liquid is evaporated in the evaporation section, in terms of heat exchange efficiency, the refrigerant is separated from the liquid in the heat exchange flow path of the nuclear power plant. It is preferable to perform heat exchange in a so-called full liquid state, which is filled with moist stem air mixed with water.

Therefore, conventionally, the following configuration has been adopted.

A. The first conventional example is called a liquid level level sensing method, in which a communicating pipe is connected to the evaporator constituting the evaporator, and the liquid level in the communicating pipe is sensed by a level sensor. On the other hand, the refrigerant supply pipe to the evaporator is provided with a flow control valve that adjusts the amount of refrigerant supplied, and the flow control valve is installed so that the liquid level known by the level sensor is maintained at or above the set level. is activated automatically to fill the entire evaporator with wet steam.

B. Second conventional example This is called a one-way type ejector, in which an accumulator is connected in communication with the outlet side of the evaporator, and the accumulator and the population side of the evaporator are connected in communication, and the evaporator has a
While converting the refrigerant into a liquid state, the refrigerant liquid is made to flow into the evaporator, the refrigerant liquid and refrigerant gas are separated in the accumulator, and while the refrigerant gas is taken out of the accumulator, the refrigerant liquid is returned to the evaporator. 5
87902).

C0 Third Conventional Example This is called superheat degree control, and in addition to the part that performs heat exchange in a full liquid state in the evaporator, there is also a heat exchange part for superheat degree to extract dry steam, which is completely saturated gas. We are prepared.

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

a. Disadvantages of the first conventional example When the liquid level in the evaporator changes instantaneously, such as during startup, the flow rate control valve has poor ability to follow it, resulting in a refrigerant liquid back-up, which disrupts the circulation of the refrigerant. There were drawbacks that hindered the

b. Disadvantages of the second conventional example Regardless of load fluctuations in the evaporator, if you try to separate the refrigerant liquid and refrigerant gas in the accumulator and extract fully saturated gas, a large achievre is required, and the refrigerant filling becomes difficult. There was a drawback that the amount increased and the efficiency of the refrigeration cycle was reduced.

C6 Disadvantages of the 3rd Conventional Example In order to reduce the superheat heat exchange part of the evaporator by 01η, the reactor becomes larger, and as in the case of the 2nd Conventional Example, the amount of refrigerant charged increases, reducing the efficiency of the refrigeration cycle. There was a drawback.

The present invention has been made in view of the above circumstances, and the evaporation control structure in the first refrigeration cycle according to the present invention allows the evaporator to heat up in a full liquid state without increasing the size of the evaporator. The purpose is to be able to take out fully saturated gas while performing exchange,
The evaporation control structure in the second refrigeration cycle according to the present invention makes it possible to efficiently take out fully saturated gas while ensuring heat exchange in the evaporator in a full liquid state. [-1 target.

<Means for Solving the Problems> In order to achieve such an objective, the nuclear power plant control structure in the first refrigerated Nicle according to the present invention includes a condensing section that cools and liquefies refrigerant gas, and a nuclear power plant control structure that vaporizes the refrigerant liquid. A refrigeration cycle comprising an evaporation section and a flow rate control valve that regulates the flow rate of refrigerant liquid liquefied in the condensation section before being supplied to the nuclear power plant section, the refrigeration cycle being connected in communication with the outlet of the evaporation section. A trap to collect the mixed refrigerant liquid is installed in the piping, and a bypass piping for taking out a part of the refrigerant gas is connected in communication between the outlet side of the evaporation section and the downstream part of the trap, and the bypass piping is used to take out the refrigerant gas. A heating means for heating the refrigerant gas, and a temperature sensor for sensing the temperature of the refrigerant gas after the heating means is attached, and the temperature sensed by the temperature sensor is maintained within a set temperature range. , an opening adjustment mechanism is provided that automatically adjusts the opening of the flow rate control valve in a state where the higher the detected temperature, the larger the opening.

In addition to the evaporation control structure in the first refrigeration cycle, the evaporation control structure in the second refrigeration cycle according to the present invention includes, in addition to the evaporation control structure in the first refrigeration cycle, the heating means in the bypass pipe. A confirmation temperature sensor is attached to detect the temperature of the refrigerant gas before heating by the temperature sensor, and the opening adjustment mechanism is configured to maintain the temperature sensed by the temperature sensor within a set range and to control the temperature detected by the temperature sensor. In order to maintain the sensed temperature at or above the set temperature, the opening degree of the above-mentioned L amount control valve is automatically adjusted in such a state that the higher the sensed temperature is, the larger the opening degree is.

According to the configuration of the evaporation control structure in the first refrigeration cycle, the set temperature range is set to a temperature range in which fully saturated gas is obtained due to the heat generated by the heating means. In the evaporation section, the refrigerant is filled in a wet vapor state, and while a trap prevents the refrigerant liquid from being taken out, a part of the refrigerant gas taken out to the bypass piping is heated, and the heated high temperature is heated. The heat of the refrigerant gas can heat the wet vapor flowing through the trap to obtain a fully saturated refrigerant gas.

Further, according to the configuration of the evaporation control structure in the second refrigeration cycle, the set temperature for the confirmation temperature sensor is set to a temperature at which a predetermined wet steam is obtained, and the set temperature for the temperature sensor is set by the heating means. By setting the temperature at which fully saturated gas is obtained during heating, the evaporator section is reliably filled with refrigerant in a wet vapor state, and the trap prevents refrigerant liquid from being taken out. However, it is possible to heat a part of the refrigerant gas taken out to the bypass pipe, and use the heat of the heated high-temperature refrigerant gas to heat the wet vapor flowing through the trap, thereby obtaining a fully saturated refrigerant gas.

<Example> Next, an example of the present invention will be described in detail based on the drawings.

First, an embodiment of the evaporation control structure in the first refrigeration cycle according to the present invention will be described.

1st Embodiment> Fig. 1 is an overall configuration diagram of a refrigeration cycle, in which a refrigerant liquid pipe 2 is connected to a condenser l serving as a condensing section that cools and liquefies refrigerant gas.
and the refrigerant gas pipe 3 are connected to each other, and the refrigerant liquid pipe 2
In addition, there is a liquid tank installed on each floor of a building such as a building.
... are connected in communication, and gas headers 5 ... provided on each floor are connected to the refrigerant gas piping 3.

An air conditioning indoor unit 8 equipped with a cooling coil 6 and a blower fan 7 as an evaporator is installed on each floor, and the cooling coil 6 is connected to the liquid header 4 and gas header 5. The refrigeration cycle is configured such that the refrigerant is circulated through the condensation H1 and the air conditioning indoor unit 8, and the cooling coils 6 of each of them, thereby cooling each room in the building.

Throughout the figure, numerals 9, . . . indicate main valves for each floor, and numerals 10, . . . indicate flow rate control valves for each cooling coil 6, respectively.

Further, 11 indicates an ice heat storage tank, and an ice making machine 512 is connected to this ice heat storage tank ll, and a pump 13 supplies water from the ice heat storage tank 11 to the ice making machine [12].
The structure is such that the fine ice produced in step 2 is returned to the ice heat storage tank 11.

Furthermore, the cooling pipe 14 and the ice heat storage tank 11 in the condenser l
are connected to each other via a pump 15, and are configured to supply cooling water obtained in the ice heat storage tank 11 to the condenser l.

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

A refrigerant gas pipe 3 is connected to the outlet side of the cooling coil 6 and is arranged at an upward slope so that the downstream side is located higher.
As shown in the detailed configuration diagram of main parts in FIG. 2, a trap 17 is provided to collect the mixed refrigerant liquid, and a trap 17 is provided downstream of the trap 17 and extends to the outlet side of the cooling coil 6. A high-bus piping 1B for taking out a part of the refrigerant gas from the cooling coil 6 is connected to the trap 17 in a state where it is inclined so as to be located lower toward the trap 17 side.

Further, a gas-liquid separator 17a is attached to the lower part of the tube 17, and a liquid return pipe 17b is connected between the gas-liquid separator +7a and the inlet side of the cooling coil 6. I! It is configured so that the liquid accumulated in the trap 17 is returned to the cooling coil 6 side.

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

In addition, in the bypass piping 18, the pilot heater 1
A temperature sensing cylinder 20 as a temperature sensor is installed downstream of 9.
The temperature sensing cylinder 20 and the flow rate control valve 10 are connected to each other via a communication pipe 20a.

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

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

A compression coil spring 26 that biases the valve body 23 toward the closing side is installed in the valve stem 24, and the compression coil spring 26 is inserted into the space of the compression coil spring 26 with a diaphragm 25 in between. The pressure equalization pipe 21 is connected in communication, and the communication pipe 2 of the temperature sensing cylinder 20 is connected to the space on the opposite side.
0a are connected in communication, and as the internal pressure changes due to temperature sensing of the refrigerant gas by the thermosensor tube 20, the internal pressure changes between the spring pressure of the compression coil spring 26 and the pressure of the refrigerant gas transmitted through the pressure equalization pipe 21. When the value becomes larger than the sum, the valve body 23 is displaced to the opening side, and as the temperature of the refrigerant gas increases from that state and the internal pressure of the sensing cylinder 20 increases, the opening degree of the valve body 23 changes. The opening degree adjustment ¥1 mechanism is configured so that the temperature is automatically adjusted to be large, and thereby the temperature sensed by the temperature sensing tube 20 is maintained within the set 't+''1 degree range.

The set temperature range of the temperature sensing cylinder 20 is such that 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 sufficient temperature range.

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

In the figure, 27 indicates a superheat degree adjusting screw.

A refrigerant liquid pipe 2 is connected to a midway point 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 rate regulating valve IO. The flow control valve IO is closed to reduce the amount of refrigerant gas leaking.

Second Embodiment FIG. 4 is a configuration diagram showing details of the main parts of the second embodiment. In this second embodiment, a double-tube heat exchanger 29 used in ice makers and the like is used as the evaporator, and an inner tube 29a
A liquid to be cooled such as water or prine flows inside the outer tube 29b, and a refrigerant whose pressure has been reduced by the flow control valve 10 is passed through the outer tube 29b in a moist state.

The other configurations are the same as those in the first embodiment, so the same numbers are given and the explanation thereof will be omitted.

In the first and second embodiments described above, the temperature sensing cylinder 20 is used as a temperature sensor, and the opening degree 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, a thermistor or thermocouple is used as the temperature sensor, and the measured temperature is input to the microcomputer to calculate the opening degree of the flow rate control valve lO corresponding to the measured temperature. However, an electronic type may be used as the flow rate control valve 10, and the calculated opening degree may be automatically obtained by the drive output from the microcomputer.

Next, an example of the evaporation control structure in the second refrigeration cycle according to the present invention will be described.

<Third Embodiment> FIG. 5 is a configuration diagram showing the details of the main parts of the third embodiment. Confirmation temperature sensor 3 that detects the temperature of refrigerant gas before heating
On the other hand, a temperature sensor 30b that senses the temperature of the refrigerant gas after being heated by the pilot heater 19 is attached at a location downstream of the pilot heater 19.

In the flow control valve IO, as shown in the longitudinal cross-sectional view of FIG.
1 are connected to each other via a communication pipe 31a, and a non-shrinkable fluid is sealed inside the pipe 31a.

A rank 33 is formed in the piston rod 32 of the control cylinder 31, and an electric motor 34 is connected to the rack 33.
A pinion gear shaft 35, which is driven and rotated by the pinion gear shaft 35, is engaged with the pinion gear shaft 35.

The confirmation temperature sensor 30a and the temperature sensor 30b
Each temperature signal is input to a control circuit 36, as shown in the block diagrams of FIGS. 5 and 7, and this control circuit 36 includes an upper limit setter 37, a lower limit setter 38, and a setter 39. A set temperature signal from the temperature sensor 30a and the temperature sensor 30b is compared with the set temperature, and a drive signal is output to the driver 40 based on the comparison results, and the drive signal is output to the electric motor 34.
The diaphragm 25 is driven forward or reverse by a predetermined amount.
A predetermined pressure is applied to the flow control valve 10, and the opening degree of the flow control valve 10 is automatically adjusted to maintain the temperature sensed by the confirmation temperature sensor 30a within the set range, and to maintain the temperature sensed by the temperature sensor 30b above the set temperature. The opening adjustment mechanism is configured to do so.

The control circuit 36 includes a first comparison means 4L, a second comparison means 42, a third comparison means 43, and a motor control means 44.

The first comparing means 41 compares the upper limit setting temperature inputted from the upper limit setting device 37 and the sensed temperature inputted from the confirmation temperature sensor 30a, and when the sensed temperature becomes higher than the upper limit setting temperature, the motor The control means 44 is configured to provide a first comparison output.

The second comparison means 42 compares the lower limit set temperature manually input from the lower limit setter 38 and the sensed temperature input from the confirmation temperature sensor 30a, and when the sensed temperature becomes lower than the lower limit set temperature, the motor The control means 44 is configured to provide a second comparison output.

The third comparing means 43 compares the set temperature input from the setting device 39 and the sensed temperature manually input from the temperature sensor 30b, and when the sensed temperature becomes lower than the set temperature, the third comparison means 43 controls the motor control means 44 to 3 comparison output.

The motor control means 44, in response to the first comparison output,
A reverse drive signal is output to the driver 40, and the electric motor 34
is configured to rotate in the opposite direction by a set amount to reduce the pressure applied to the diaphragm 25 and displace the valve body 23 to the closing side, and in response to the second and third comparison outputs, the driver A forward rotation drive signal is output to the diaphragm 25 to rotate the electric motor 34 in the forward direction by a set amount.
The pressure applied to the valve body 23 is increased to displace the valve body 23 toward the opening side.

The setting temperature of the upper limit setter 37 is set at a dryness level of 10
For example, when the temperature is 0%, the temperature is set to a value that does not exceed 90%, and the lower limit setting device 38 is set to a temperature that corresponds to a temperature that is, for example, 85%. be done. The upper limit setting device 37 and the lower limit setting device 38 are each configured to be able to change the set temperature as appropriate.
It is possible to set desired heat exchange conditions as appropriate, such as performing heat exchange in a state of about 0% wet steam.

The setting temperature of the setting device 39 is set so that not only the refrigerant gas heated by the pilot heater 19 but also the cold gas mixed with the heated refrigerant gas and taken out to the refrigerant gas pipe 3 becomes a completely saturated gas. The temperature is set to a sufficient temperature.

- With the above configuration, the pressure applied to the diaphragm 25 is adjusted based on the temperature sensed by the confirmation temperature sensor 30a and the temperature sensor 30b, and the pressure is transmitted through the pressure equalization pipe 21 and the spring pressure of the compression coil spring 26. The opening degree of the valve body 23 is adjusted based on the difference between the pressure of the refrigerant gas and the sum of the refrigerant gas pressures.

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

<Fourth Embodiment> FIG. 8 is a configuration diagram showing details of the main parts of the fourth embodiment. This fourth embodiment uses a double-tube heat exchanger fA, which is used in ice makers, etc., as an evaporation section, as explained in the second embodiment.
2 and 29, the refrigerant gas that has been heat exchanged in a wet vapor state with a liquid to be cooled such as water or brine flowing in the inner pipe 29a is taken out from the outer pipe 43b,
The temperature of the refrigerant gas is sensed by the confirmation temperature sensor 30a, and the temperature of the refrigerant gas after being heated by the pilot heater I9 is sensed by the temperature sensor 30b, in the same manner as described in the first embodiment. , confirmation temperature sensor 30
The temperature sensed by a is maintained within the set range, and
The opening degree of the flow rate regulating valve 10 is automatically adjusted so that the temperature sensed by the temperature sensor 30b is equal to or higher than the set temperature.

The other +fl components are the same as those in the third embodiment, and are given the same numbers and their explanations will be omitted.

The refrigeration cycle of the above embodiment is configured to cause the refrigerant to flow through natural circulation by vaporizing and liquefying the refrigerant, but it can also be applied to a refrigeration cycle having a compression process and an expansion process. An expansion valve may be used as the R amount control valve, and the above-mentioned nuclear power plant control may be performed by adjusting the opening degree of the expansion valve.

<Effects of the Invention> According to the evaporation control structure in the first refrigeration cycle according to the present invention, the evaporation section can be enlarged by adding a bypass pipe and a trap and providing a heating means and a temperature sensor in the bypass pipe. The evaporator section is filled with refrigerant in a moist, brownish state, and a fully saturated refrigerant gas is obtained, improving the heat exchange efficiency in the evaporation section.Moreover, the trap prevents refrigerant liquid back-up. Moreover, since there is no need to add an accumulator or heat exchanger for superheating as in the conventional case, there is no need to increase the amount of refrigerant charged, which avoids impeding the efficiency of the refrigeration cycle, resulting in high efficiency as a whole. It has now become possible to construct a stable refrigeration cycle that can perform good evaporation processing and obtain fully saturated gas.

According to the evaporation control structure in the second refrigeration cycle according to the present invention, in addition to the structure of the evaporation control structure in the first refrigeration cycle described above, the evaporation control structure is taken out from the neck part into the bypass pipe and heated by the heating means. A confirmation temperature sensor is attached to detect the temperature of the refrigerant gas before it is heated, and an opening adjustment mechanism adjusts the opening of the flow rate control valve so that the temperature detected by the confirmation temperature sensor remains within the set range. Therefore, the refrigerant taken out from the evaporator can be reliably maintained in a wet vapor state, and the tH degree of the refrigerant gas after being heated by the heating means can be maintained at l,
! ! The temperature is detected by a temperature sensor, and the opening of the flow control valve is adjusted so that the detected temperature is higher than the set temperature, so the refrigerant taken out from the evaporator and sent to the condenser can be in a completely saturated gas state, and the surrounding Even if there is a change in the amount of heat applied by the heating means due to changes in temperature or load fluctuations on the heating means, the evaporator section reliably maintains a full liquid state and performs heat exchange, achieving complete saturation. It has become possible to construct a stable refrigeration cycle that can reliably obtain gas and perform evaporation processing with higher efficiency and better performance to obtain fully saturated gas.

[Brief explanation of the drawing]

The drawing shows an evaporator converter I in a refrigeration cycle according to the present invention.
・An example of the roll structure is shown. Fig. 1 is an overall configuration diagram of the refrigeration cycle, Fig. 2 is a configuration diagram showing details of the main parts of the first embodiment, and Fig. 3 is a vertical cross-section of the flow rate control valve. 4 is a block diagram showing the details of the main part of the second embodiment, FIG. 5 is a block diagram showing the details of the main part of the third embodiment, and FIG. 6 is a block diagram showing the details of the main part of the third embodiment. FIG. 7 is a block diagram showing the configuration of the opening adjustment mechanism, and FIG. 8 is a configuration diagram showing details of main parts of the fourth embodiment. 1... Condensation 2z as a condensing part 6... Cooling coil IO as an evaporation part...'/A crab control valve 17... Trap 18... Bypass piping 19... As a heating means Pilot heater 20...
- Temperature sensing tube 29 as a temperature sensor...Double pipe heat exchanger 30a as an evaporation part...
・Temperature sensor for confirmation 30b...Temperature sensor applicant: Takenaka Komu Co., Ltd.

Claims (2)

[Claims] (1) A condensing section that cools and liquefies refrigerant gas, an evaporating section that evaporates and vaporizes refrigerant liquid, and a flow rate adjustment valve that adjusts the flow rate of the refrigerant liquid liquefied in the condensing section before being supplied to the evaporating section. A refrigeration cycle equipped with a trap for collecting mixed refrigerant liquid is provided in a pipe connected to an outlet of the evaporation section, and the refrigerant is disposed between an outlet side of the evaporation section and a location downstream of the trap. A heating means that connects a bypass pipe from which a portion of the gas is taken out, and heats the taken-out refrigerant gas to the bypass pipe;
A temperature sensor is attached to detect the temperature of the refrigerant gas after heating by the heating means, and in order to maintain the temperature sensed by the temperature sensor within a set temperature range, the higher the sensed temperature is, the larger the opening degree is. An evaporation control structure in a refrigeration cycle, comprising an opening adjustment mechanism that automatically adjusts the opening of the flow rate control valve. (2) In the evaporation control structure in the refrigeration cycle according to claim (1), in the bypass piping,
A confirmation temperature sensor that senses the temperature of the refrigerant gas before heating by the heating means is attached, and the opening adjustment mechanism maintains the temperature sensed by the confirmation temperature sensor within a set range, and also maintains the temperature sensed by the temperature sensor. An evaporation control structure in a refrigeration cycle configured to automatically adjust the opening degree of the flow control valve in such a state that the higher the sensed temperature, the larger the opening degree, so as to maintain the temperature above a set temperature.