Patent Application
20240377142
The present invention relates to a waste cold/warm heat recycling heat exchange device which recovers and recycles waste cold heat or waste warm heat which is lost from various energy consumption devices including an air conditioning device, using refrigerant which circulates in a closed loop between an evaporator and a condenser.
In a heat exchange device, which uses an evaporator and a condenser, when a temperature difference between refrigerants which pass through the evaporator and the condenser is large, the refrigerants are evaporated and condensed.
The evaporation and condensation of the refrigerant cause a pressure difference between an outlet of the evaporator and an inlet of the condenser and between an outlet of the condenser and an inlet of the evaporator so that a thermosiphon action in which the refrigerant flows and circulates along a pressure gradient of a refrigerant pipe which connects the evaporator and the condenser without a separate power occurs.
A basic principle of the heat exchange device using the thermosiphon action (hereinafter, referred to as “thermosiphon heat exchange device”) was introduced in Korean Registered Patent No. 10-1294939.
The thermosiphon heat exchange device is advantageous to circulate a refrigerant on its own without a separate external power to move the heat so that it is frequently used for a waste cold/warm heat recycling heat exchange device which is provided in a device in which waste cold heat or waste warm heat is generated, such as an air conditioning device of the related art, to improve the heat efficiency.
However, in the thermosiphon heat exchange device of the related art, when a temperature difference between refrigerants passing through the evaporator and the condenser is small, the thermal equilibrium and the pressure equilibrium may be easily generated in a liquid refrigerant pipe and a gas refrigerant pipe which connect the evaporator and the condenser. In this case, the flow of the refrigerant stops so that there is a problem in that the effect of recovering the waste cold/warm heat cannot be expected by the circulation of the refrigerant that is repeatedly evaporated and condensed.
Further, after the thermal equilibrium and the pressure equilibrium are generated in the refrigerant pipe, the liquid refrigerant in the evaporator in which the temperature and the pressure are generally increased flows in the reverse direction toward the condenser to lose the function as the heat exchange device.
Due to this problem, a heat exchange device is also used to additionally install a refrigerant compressor, a reheater, or the like in the thermosiphon heat exchange device to forcibly solve the thermal equilibrium and the pressure equilibrium state of the refrigerant and prevent the refrigerant from flowing in a reverse direction.
However, as compared with the thermosiphon heat exchange device of the related art which is freely installed in various heat exchange devices or waste heat generation locations, a thermosiphon heat exchange device which needs to consider the location of a power supply device for a refrigerant compressor or a heat source device for a reheater has a lot of restrictions of installation environments.
Further, in order to operate the refrigerant compressor or the reheater, very high external energy is further consumed so that there is a problem in that the inherent advantage of the thermosiphon heat exchange device that consumes almost no external energy is lost. Further, as the device becomes complex, the failure rate increases and the production cost and the maintenance cost of the product increase.
In the meantime, the inventor of the present invention improved the thermosiphon heat exchange device of the related art to apply for the thermosiphon heat exchange device illustrated in FIG. 1 to be published in Korean Unexamined Patent Application Publication No. 10-2018-0029474.
In the thermosiphon heat exchange device illustrated in
Accordingly, in the case of the thermosiphon heat exchange device illustrated in
As described above, according to the thermosiphon heat exchange device of Korean Unexamined Patent Application Publication No. 10-2018-0029474, the problem in that the flowing direction of the refrigerant is reversed due to the thermal equilibrium and pressure equilibrium state generated in the thermosiphon heat exchange device of the related art which does not include a check valve may be solved without using a separate power device for removing the refrigerant thermal equilibrium and pressure equilibrium state.
However, the thermosiphon heat exchange device of Korean Unexamined Patent Application Publication No. 10-2018-0029474 still has problems in that when the temperature difference between the refrigerants which pass through the evaporator 10 and the condenser 20 is small, the thermal equilibrium and pressure equilibrium state is easily generated in the liquid refrigerant pipe 40 and the gas refrigerant pipe 30 to stop the flow of the refrigerant and the effectiveness of the heat exchange device which recovers the waste cold/warm heat cannot be expected until the pressure difference recovers to a significant level enough to pass through the check valve.
In order to solve the problems of the related art, an object of the present invention is to provide a configuration of a highly efficient waste cold/warm heat recycling heat exchange device which maintains stable circulation of refrigerant by inputting only a minimum external energy even though the refrigerant thermal equilibrium and pressure equilibrium is generated between the outlet of the evaporator and the inlet of the condenser and between the outlet of the condenser and the inlet of the evaporator.
Further, another object is to provide a configuration of a highly efficient waste cold/warm heat recycling heat exchange device which automatically adjusts an optimal amount of refrigerant which is injected into the evaporator during an operation for recycling the waste cold/warm heat.
Furthermore, another object is to provide a configuration of a highly efficient waste cold/warm heat recycling heat exchange device which facilitates the task of charging an optimal amount of refrigerant during a trial running step.
In order to achieve the above-described objects, according to the present invention, a gas refrigerant pipe which connects an outlet of an evaporator and an inlet of a condenser and a liquid refrigerant pipe which connects an outlet of the condenser and an inlet of the evaporator are installed to circulate a refrigerant in a closed loop between the evaporator and the condenser, a digital sensor for detecting internal refrigerant pressure and temperature and inputting the detected values to a controller is installed in the condenser, a liquid transfer pump is installed on the liquid refrigerant pipe to push the liquid refrigerant toward the evaporator, and the controller which receives the detected values from the digital sensor controls the operation of the liquid transfer pump according to the detected values to adjust a flow rate of the liquid refrigerant which flows through the refrigerant pipe.
Further, a solenoid valve is further installed on the liquid refrigerant pipe of the present invention and the controller which receives the detected values of the digital sensor may be configured to adjust a passage opening rate of the solenoid valve according to the detected values.
After controlling the liquid transfer pump to stop the operation, the controller determines whether detected refrigerant pressure and temperature values in the condenser detected by the digital sensor satisfy a defined change value after a predetermined time, and if the detected values do not satisfy the defined change value, the controller controls the passage opening rate of the solenoid valve.
According to the present invention, even though the refrigerant thermal equilibrium and pressure equilibrium is generated between the outlet of the evaporator and the inlet of the condenser and between the outlet of the condenser and the inlet of the evaporator, the waste cold/warm heat recycling heat exchange device can control the liquid transfer pump to maintain stable circulation of refrigerant. Specifically, a circulation amount of refrigerant can be automatically adjusted according to a degree of generated thermal equilibrium and pressure equilibrium so that not only the stable circulation of refrigerant, but also an operation for achieving high-efficient optimization of waste cold/warm heat recovery is enabled.
Further, according to the present invention, it is advantageous in that even low-skilled workers may easily check whether the appropriate amount of refrigerant is charged during a trial running step after initially installing the device or the recharging process for maintenance to make it easy to install and maintain the device.
Further, the waste cold/warm heat recycling heat exchange device of the present invention has advantages in that it can be installed in a front end or a rear end of a heat exchanger for cooling or heating regardless of a type of the existing air conditioning device or an evaporator or a condenser can be separately installed in a location for utilizing waste heat so that it is applied to a site that is lost in various types of energy consumption devices to actively and freely recycle the waste cold/warm heat.
That is, the waste cold/warm heat recycling heat exchange device of the present invention may be very usefully utilized for strengthening the dehumidification function of a constant temperature and humidity device or an existing air conditioner that requires a reheating process after precooling, or for precooling and preheating a high temperature and dehumidifying dryer, for recycling exhaust waste heat of a ventilation duct, and the like.
Hereinafter, preferred exemplary embodiments of a highly efficient waste cold/warm heat recycling heat exchange device of the present invention will be described in detail with reference to the accompanying drawings.
Terms used for description of the present invention may include terms defined by considering functions in the present invention. Since the terms used in the present invention may be expressed in different terms depending on the intention or custom of other designers or users, actual definitions of these terms should be made by taking into account the contents described throughout the specification.
Further, directional terms used in the description of the present invention, such as “top”, ‘bottom’, ‘front’, ‘back’, ‘front’, ‘rear’, ‘left’, ‘right’, ‘front end’, ‘rear end’, etc. are based on the orientation of the disclosed drawing(s). However, the components of the exemplary embodiment of the present invention may be located in various orientations so that the directional terms are used for illustrative purpose but are not limiting.
When it is described that the components used in the present invention are ‘connected’, ‘coupled’, or ‘fastened’ to each other, it should be understood that this also includes cases where they are connected, coupled, or fastened indirectly through intermediate components.
Herein, the detailed description of a known function and configuration that may make the gist of the present invention unnecessarily ambiguous will be omitted.
As illustrated in
Further, in the present invention, a swing-type check valve 31 is further installed in the gas refrigerant pipe 30 and a ball-type check valve 41 is further installed in the liquid refrigerant pipe 40. The installation configuration of the check valves is the same as disclosed in Unexamined Patent Application Publication No. 10-2018-0029474 mentioned as the related art (see
When a refrigerant pressure at the outlet side of the evaporator 10 is higher than a refrigerant pressure at the inlet side of the condenser 20 by a predetermined pressure difference, the check valve 31 is open to flow the gas refrigerant to the condenser 20 and when a refrigerant pressure at the outlet side of the condenser 20 is higher than a refrigerant pressure at the inlet side of the evaporator 10 by a predetermined pressure difference, the check valve 41 is open to flow the gas refrigerant to the evaporator 10.
As illustrated in
The liquid transfer pump 46 is a device which forcibly pushes the liquid refrigerant on the liquid refrigerant pipe 40 to the evaporator 10 and has a totally different function, action, and effect from a “compressor” which compresses the gas refrigerant at a high temperature and high pressure to be ejected to the condenser, in the general heat exchange device.
As described above, when the temperature difference between the refrigerants which pass through the evaporator 10 and the condenser 20 is small, it is close to the thermal equilibrium and pressure equilibrium state between the liquid refrigerant pipe 40 and the gas refrigerant pipe 30 so that the flow of the refrigerant in the closed loop becomes so weak that the recovery efficiency of the waste cold/warm heat is hardly expected.
According to the present invention, when the flow of refrigerant is very weak, the liquid transfer pump 46 is used to forcibly push the liquid refrigerant to maintain the refrigerant circulation cycle. Therefore, this is a device having a different purpose and function from a compressor which compresses the gas refrigerant at a high temperature and high pressure in a general heat exchange device.
Further, the liquid transfer pump used in the present invention is sufficient to have a liquid transfer ability to simply induce the flow of the liquid refrigerant so that a small capacity pump may be used.
That is, it was confirmed that in the thermosiphon heat exchanger of the present invention, when the liquid transfer pump generated a fluid pressure of 0.5 kgf/cm2, normal liquid refrigerant flow started. Accordingly, as the liquid transfer pump of the present invention, a liquid transfer pump in which the passing liquid refrigerant generates a pressure increase of at least 0.5 kgf/cm2 or slightly higher than that before passing the liquid transfer pump is adopted.
The solenoid valve 47 may be installed between the liquid transfer pump 46 and the evaporator 10 to intermittently control the liquid refrigerant ejected from the liquid transfer pump 46. The solenoid valve 47 is installed to prepare for a case that the refrigerant does not exactly flow out from the liquid transfer pump 46 simply by stopping the operation of the liquid transfer pump 46 and allows for more reliable control of the flow of the liquid refrigerant.
In the present invention, a digital sensor 45 and a controller 50 are installed to control the liquid transfer pump 46 and the solenoid valve 47.
The digital sensor 45 is used to detect a temperature and a pressure and is installed to be close to the condenser 20. Desirably, as illustrated in
The controller 50 which receives detected values of the temperature and the pressure detected by the digital sensor 45 to generate a signal for controlling operations of the liquid transfer pump 46 and the solenoid valve 47 is installed in a predetermined position.
As the controller 50, a micro controller unit (MCU) may be used and the controller automatically controls a flow rate of the liquid refrigerant which flows through the refrigerant pipe 40 by controlling the operations of the liquid transfer pump 46 and the solenoid valve 47 according to the state of the liquid refrigerant in the condenser 20.
That is, the controller 50 determines how much the detected values of the temperature and the pressure detected by the digital sensor 45 exceed or fall below a predetermined range and controls the operation of the liquid transfer pump 46 in proportion to the magnitude of the excess or deficiency to adjust the refrigerant ejection amount or completely stop the ejection.
Further, the controller 50 may control by generating a signal which increases or decreases a passage opening rate of the solenoid valve 47 or closes the passage and organically interworking with the control of the liquid transfer pump 46.
An expansion valve 44 is a means to achieve a throttling effect of the liquid refrigerant. The liquid refrigerant which passes through the expansion valve 44 is throttled to cause the pressure drop. If the pressure drop is excessive so that the pressure drops below a saturation pressure, a part of the liquid refrigerant evaporates to generate flash gas. The flash gas absorbs the evaporation heat from the liquid refrigerant to lower the temperature of the liquid refrigerant.
The expansion value 44 may be installed as an electronic or sensitive expansion valve by taking into account the heat capacity of the heat exchange device or may be installed by selecting an alternative from devices which cause the throttling action, such as a capillary tube or a globe valve.
Pressure gauges 32 and 42 illustrated in
In the exemplary embodiment of the present invention illustrated in
The distributor 11 serves to distribute a small amount of flash gas and a low-temperature and low-pressure liquid refrigerant which pass through the expansion valve 44 to be transmitted through the refrigerant pipe 40.
The distribution tubes 12 are separately coupled to heat exchange tube ends of the evaporator so that the refrigerant entering from the liquid refrigerant tube 40 is uniformly distributed and introduced to the entire evaporator via the distributor 11 and the distribution tubes 12.
Gas exclusive headers 13 and 21 are installed in the refrigerant outlet of the evaporator 10 and the refrigerant inlet of the condenser 20 and the liquid exclusive header 22 is installed in the refrigerant outlet of the condenser 20.
The headers function to help the refrigerant flow in or out smoothly between the refrigerant pipe and the evaporator or the condenser.
In the exemplary embodiment of the present invention, a blower fan 23 serves to blow and heat external air (or air from a waste cold heat generated location) toward the heat exchange tube of the condenser 20 to make it hot air and introduce the hot air into the room.
Hereinafter, an example in which the present invention is used as a waste cold heat recycling heat exchanger which supplies the heated air to the indoor such as a hot temperature dry room using waste cold heat in a waste cold heat source which discharges cold air is described with reference to
In the normal heat exchanger, refrigerant which is introduced into the evaporator is in a low temperature/low pressure liquid state and the refrigerant exchanges heat (absorbs heat) with the outside air in the evaporator to evaporate to be discharged in a low temperature/low pressure gas state. The gas refrigerant in the low temperature/low pressure state is compressed in a high temperature/high pressure overheated gas state through a compressor and then goes into the condenser to exchange heat (dissipate heat) with the outside air to be discharged in the high temperature/high pressure liquid state. The high temperature/high pressure liquid refrigerant becomes a low temperature/low pressure liquid state by the throttling operation in the expansion valve to be introduced into the evaporator again to form a circulation cycle of the refrigerant.
In the normal heat exchanger, a pressure of the condenser is higher than a pressure in the evaporator so that the low temperature/low pressure gas refrigerant which is discharged from the evaporator cannot be transferred to the condenser without the compressor.
However, in the present invention, an evaporation action in which the refrigerant is vaporized in the evaporator 10 is consistently performed for a predetermined time or longer to increase an amount of vaporization of the refrigerant to make the low temperature/low pressure gas refrigerant generated in the evaporator 10 a high temperature/high pressure state on its own.
That is, according to the present invention, the pressure of the gas refrigerant discharged from the evaporator 10 may be higher than a pressure at the inlet of the condenser 20 by a predetermined pressure or higher so that the refrigerant may be transferred to the condenser 20 without a separate process of making the gas refrigerant in a high temperature/high pressure state by the compressor.
As described above, when the outlet pressure of the evaporator 10 is larger than the inlet pressure of the condenser 20, the swing-type check valve 31 installed in the gas refrigerant pipe 30 is open toward the condenser by the pressure difference and the gas refrigerant is automatically introduced into the heat exchange tube of the condenser 20 along paths of the check valve 31 and the gas exclusive header 21 through the gas refrigerant pipe 30.
Next, the high temperature/high pressure gas refrigerant introduced into the condenser 20 exchanges heat (dissipates heat) with the outside air to cause the condensation action so that the state is changed to the high temperature/high pressure liquid refrigerant in the condenser 20.
In the present invention, the digital sensor 45 is installed in a lower side of the liquid exclusive header 22 located close to the outlet of the condenser 20 and the controller 50 receives temperature and pressure information of the liquid refrigerant in the condenser detected by the digital sensor 45.
The controller 50 determines whether the pressure of the liquid refrigerant detected by the digital sensor 45 is within a predetermined pressure range (for example, when the liquid refrigerant pressure in the condenser is within 0.5 to 1.5 kgf/cm2, it may be determined to be normal) and controls the operation of the liquid transfer pump 46 and the solenoid valve 47 according to the result value.
In the present invention, when the liquid refrigerant in the condenser 20 increases to a predetermined pressure range (for example, pressure exceeding the range of 0.5 to 1.5 kgf/cm2), the pressure difference between the evaporator outlet and the condenser inlet is very small, or the inlet of the condenser may have a higher pressure.
In this case, the pressure of the gas refrigerant which flows from the evaporator to the condenser is not high enough to open the swing-type check valve 31 so that the flow of the gas refrigerant is blocked by the check valve 31 to be stopped.
Accordingly, in the present invention, when the digital sensor 45 detects that a pressure of the liquid refrigerant in the condenser 20 exceeds a predetermined pressure range (for example, 0.5 to 1.5 kgf/cm2 or higher), the controller 50 operates the liquid transfer pump 46 and controls the solenoid valve 47 to be open to forcibly circulate the refrigerant. Therefore, the high temperature/high pressure gas refrigerant ejected from the evaporator may be consistently introduced into the condenser 20.
When the refrigerant forcible circulation state is maintained, the high temperature/high pressure liquid refrigerant ejected from the condenser 20 is consistently introduced into the evaporator 10 so that the pressure of the gas refrigerant generated in the evaporator 10 is gradually increased.
The pressure of the gas refrigerant ejected from the outlet of the evaporator 10 eventually increases until it becomes almost equal to an internal pressure of the condenser 20, so that the pressure difference therebetween may drop below a predetermined pressure difference (for example, when the pressure in the condenser detected by the digital sensor 45 is detected to be 0.5 to 1.5 kgf/cm2).
In this case, the controller 50 which receives the detected signal from the digital sensor 45 controls the liquid transfer pump 46 to be stopped and eventually, the circulation of the refrigerant is stopped.
In a state in which the circulation of the refrigerant is stopped, the gas refrigerant remaining in the condenser 20 continuously exchanges heat with the outside air so that the condensation further progresses to gradually decrease the refrigerant pressure of the condenser 20. In contrast, the liquid refrigerant remaining in the evaporator 10 continuously exchanges heat with the outside air to be further evaporated so that the refrigerant pressure in the evaporator 20 may gradually increase.
Here, even though the controller 50 stops the operation of the liquid transfer pump 46, if the liquid refrigerant is leaked from the liquid pump to the refrigerate pipe 40 to continuously circulate a small amount of the liquid refrigerant, the rising rate of the refrigerant pressure in the evaporator 20 may be excessively slow.
Therefore, if the detected refrigerant pressure and temperature values in the condenser 20 detected by the digital sensor 45 do not satisfy a specified change value when a predetermined time has elapsed after stopping the operation of the liquid transfer pump 46, the controller 50 determines that the liquid refrigerant is leaked from the stopped liquid pump to control the passage opening rate of the solenoid valve 47 to be between 0% and 100%.
The digital sensor 25 installed in the condenser 20 detects that the liquid refrigerant in the condenser 20 enters a predetermined pressure range when a predetermined time has elapsed after the control, so that the controller 50 which receives the detected signal operates the liquid transfer pump 46 and controls the solenoid valve 47 to be open and the swing-type check valve 31 of the liquid refrigerant pipe 30 is open. Therefore, the refrigerant may undergo the circulation cycle in the closed circuit again.
Next, in the exemplary embodiment of
The distributer 11 installed at the inlet of the evaporator 10 and the distribution tubes 12 branched from the distributer 11 are coupled to each of ends of heat exchange tubes of the evaporator 10 so that the refrigerant introduced through the distributer 11 is evenly distributed to the entire evaporator to more efficiently perform the evaporation action in the evaporator 10.
The evaporator 10 in which the liquid refrigerant in the low temperature/low pressure in the expansion valve 44 is introduced exchanges heat (absorbs heat) with the outside air to maintain the evaporation action which vaporizes the refrigerant for a predetermined time or longer to make it a high temperature/high pressure gas state to be ejected to perform the continuous circulation of the refrigerant.
In the meantime, in the present invention, the digital sensor which is installed in the liquid exclusive header 45 installed close to the outlet of the condenser 20 to detect a predetermined pressure may be used to simply check the refrigerant charging state at the time of initial installation or maintenance.
That is, in the related art, when the refrigerant is injected for the first time after installing the heat exchange device or the refrigerant is replenished for the maintenance purpose, the worker needs to do the task while measuring the pressure of the injected refrigerant using a separate pressure gauge, which requires a predetermined level of skill.
However, according to the present invention, the digital sensor 45 accurately detects and displays the refrigerant charging state in the condenser 20 so that when the worker injects the refrigerant, the worker may inject the refrigerant just until a predetermined pressure is displayed by simply watching the digital sensor 45 to complete the task. Accordingly, even though the skill level of the worker is low, the worker may accurately and easily perform the refrigerant injection task.
Those skilled in the art of the present invention may improve or change the technical ideas of the present invention to various forms. Accordingly, the exemplary embodiment of the present invention which has been described above and illustrated in the drawing should not be construed as limiting the technical spirit of the present invention. That is, if the improvements and changes are easy for those skilled in the art, the improvements and changes will fall within the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0108714 | Aug 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/012372 | 8/18/2022 | WO |
