KR20180055833A - Air conditioner - Google Patents

Abstract

An air conditioner is provided. The air conditioner includes a compressor (301) and a condenser (302). The air conditioner has an overheat remover 303 provided in the flow path from the compressor to the condenser.

Description

Air conditioner

The present disclosure relates to an air conditioner. In particular, the present disclosure relates to a portable air conditioner.

Air conditioning (AC) is an integrated representation of conditioning air into the desired state. The air conditioning can heat the air during the low temperature period, cool the air during the hot period, or clean the air if the air contains unwanted particles. However, the expression of air conditioning is most often used when emphasizing cooling. As a product, an air conditioner can be seen and used in various ways, but all of the air conditioners share the same basic technology.

Existing portable air conditioners are often large, difficult to handle, noisy and inefficient. In addition, the connected exhaust air outlets for removing heat from the room are often complicated and inefficient in its design. A known portable air conditioner is described, for example, in U.S. Patent No. 2,234,753.

The design of the portable AC system differs from that of other air handling systems, which are mounted inside a packed unit that must be operated within the space in which all components of the system are conditioned, and the residual energy (generated in a typical cooling process) Through an air exhaust system that is generally connected to the outside.

In a portable AC unit, there are two general processes for cooling an air source condenser: a single conduit method and a dual conduit method. In the first method (single conduit), the system takes air from its surroundings (the conditioned space) Force air to pass through the condenser surface, and finally remove residual energy from the condenser surface. Then, by using a single conduit system, hot air is discharged outdoors. In this way, the intake air temperature has a room temperature condition, which makes the energy exchange process more advantageous in terms of the cooling cycle.

In the dual conduit method, the system utilizes an air intake conduit to cool the condenser by injecting "hot" air from the outside. Finally, the air from the condenser at a relatively high temperature is again discharged to the outside by the secondary exhaust conduit. In this way, the air intake temperature is an outdoor temperature condition. This method can provide a faster cooling effect for the user, since the system does not use room air as the cooling medium for the condenser, but this results in a larger size / volume to compensate for the higher inlet outdoor temperature ≪ / RTI >

Both methods, namely single and double ducts, have different limits in relation to: air flow rate, size of heat exchanger and also the dimensions of the air piping system.

Such peculiarities require portable AC systems to utilize special sized condensers to limit the maximum air flow rate used by the system because the air intake and air exhaust systems must be as compact as possible.

The air flow rate in the portable AC system is also limited by the noise level because many air flows through small diameter hoses result in greater pressure drop and higher noise levels. In that sense, a single conduit system has a clear advantage over a dual conduit system because the temperature difference between the intake air and the condensation temperature of the cycle is large and requires a small air flow rate to perform the heat removal process.

Accordingly, in the case of portable AC systems, the condenser is one of the most important components in the design because the condenser must exchange more heat load with a very limited air flow rate. As such, such specificities affect the overall design of the condenser and the overall system performance in a considerable manner.

One way to improve condenser capacity in a portable AC system is by using condensed water from the evaporator at relatively low temperatures to remove some of the heat load on the condenser.

Some portable AC designs have a drainage system that uses water from an evaporator that drips over the condenser to reduce the surface temperature and subsequently obtain a low condensation pressure in the cycle.

In addition to the dewatering method, some other systems involve the use of wheels that scatter excess water that has not evaporated from the lower end of the condenser on its surface. This mechanism allows a portion of the excess water to be removed through the air stream across the condenser.

Such a method helps lower the condensation temperature in the cooling cycle and also helps to remove some of the undesirable condensed water produced in the normal operating process of the system.

There is a continuing need for improved operation of the air conditioner.

Accordingly, an improved air conditioner is required.

It is an object of the present invention to provide an improved air conditioner that at least partly solves the problems of existing air conditioners. According to one aspect, there is a problem associated with the description of the vapor compression cycle of the air conditioner, particularly with regard to the problem with the portable AC unit working with the air source heat exchanger.

These and other objects are achieved by a portable air conditioner as described in the appended claims. Also disclosed is an apparatus that can be used with a portable air conditioner.

By the use of an external desuperheater which has the function of initiating the condensation of the coolant prior to the coolant entering the condenser, typically the air cooled heat exchanger, the hot gas delivered by the compressor and the It is possible to take advantage of a large temperature difference between the low temperature water.

According to one embodiment, an air conditioner is provided. The air conditioner has a compressor and a condenser. The air conditioner further includes an overheat eliminator provided in the flow path from the compressor to the condenser.

According to some embodiments, the air conditioner is a portable air conditioner.

According to some embodiments, the superheat eliminator is located within the open cavity.

According to some embodiments, the air conditioner is configured to supply condensed water to the open cavity.

According to some embodiments, a pipe is provided and configured to direct condensed water dripping from the evaporator into the open cavity.

The present invention will now be described in more detail, by way of non-limiting example, and with reference to the accompanying drawings.
Figure 1 shows a TS diagram for a standard refrigeration cycle using an air source heat exchanger as a condenser.
Figure 2 shows a TS plot for a cooling cycle using an external superheat eliminator.
3 shows an air conditioner having an external superheat eliminator.
Figs. 4 and 5 show different shapes of the portable air conditioner in side sectional views and top-end sectional views, respectively.
Figure 6 shows a possible configuration of an embodiment having a coating material on a connecting pipe.
Figure 7 shows a possible embodiment of a coating element on the connecting pipe.
Figure 8 shows an embodiment including an auxiliary water pumping system for removing uncondensed water.
Figure 9 shows an embodiment with unvaporized water collected in a water tank.
Figure 10 shows a general principle of an air conditioner system.

In a standard portable AC, working with an air source heat exchanger, a heat removal process is initiated when the hot gases delivered by the compressor enter the condenser. On the inside of the condenser, a cooling process of high pressure and temperature coolant is initiated to release the heat load through the air stream across the heat exchanger surface.

Under such conditions, a significant percentage of the total area of the condenser is for the first time to reduce the bulk temperature of the gas until the gas reaches the saturation temperature in the internal superheat process. As the density of the superheated vapor stream is relatively low, the volume occupied by the coolant is relatively large, especially before the phase-change process begins to condense.

Due to this fact, in order to reduce the bulk temperature of the hot gas until the hot gas reaches the saturation condition, the size of the heat exchanger accommodating the hot gas, in particular the area for superheat removal of the coolant and the size of the inner volume . Then, once the thermodynamic vapor quality of the coolant is equal to 1, condensation and subsequent subcooling processes will occur in the remaining heat exchanger internal volume.

Figure 10 shows a general principle of an air conditioner system. The main part of the system is a compressor 101, an evaporator 103, a condenser 105, and an expansion device 107, such as a capillary tube. A condenser fan 109 and an evaporator fan 111 may also be provided. The compressor is connected in a circuit having a condenser, an evaporator, and an expansion device. The coolant can be converted from liquid to vapor, thereby having the ability to change the temperature. The tempered coolant and the room air cooperate to exchange heat with each other.

Figure 1 shows a T-S chart for a standard refrigeration cycle using an air source heat exchanger as a condenser, operating under typical temperature conditions for a portable AC application. Figure 1 includes a standard approach to the heat removal sub-process that occurs inside the condenser: DSH, phase-change, cold cooling (blue line) indicating the inlet and outlet temperature of the air flow across the condenser .

In the heat removal process shown in FIG. 1, the superheated steam removes the first sensible heat along the single-phase superheat removal zone DSH. Then, the condensation starts from equilibrium vapor quality 1, where the saturated coolant removes latent heat during its condensation (two-phase process). Finally, at the end of the condenser, the chilled liquid removes sensible heat through the single-phase cold-cooling zone (SC). The superheat removal can be described as a process of restoring the superheated steam to its saturated state or reducing the superheat temperature. This process can be performed by an overheat eliminator.

In an air cooled condenser, the temperature of the air stream around the superheat removal section strongly affects the gas superheat process. The ambient air temperature is generally influenced by circuit design and other geometric parameters such as the relative position of the coolant inlet port, the number of passes, the number of rows, the air flow rate, and so on.

However, in the particular case of portable AC systems, the geometric limitation in the dimensions of the air exhaust conduits regulates the air flow across the condenser, resulting in a large temperature gradient through the air path across the condenser from the inlet to the outlet , Thereby causing the air temperature around the superheat removal section to become too high.

On the other hand, since the fluid flow arrangement is generally fixed in the configuration of the countercurrent flow type, in most cases, the superheat removal section of the condenser removes energy from the first row of the condenser and the previously- do. This fact also affects an increase in the temperature of the air stream surrounding the rear row of the condenser, where the superheat eliminator inlet port is generally located.

Both of these effects, i.e., the large temperature gradient of the air surrounding the superheat-free zone of the condenser and the relative position of the inlet gas port make the wall temperature of the pipe in the superheat eliminator zone generally higher than the saturating temperature of the coolant, A long and insufficient superheat process inside the condenser is introduced and then a larger heat transfer area is required to complete the condensation process.

In order to improve the heat transfer process in air-source condensers, especially in portable air conditioners, air-cooled condensers, an external superheat can be provided.

The superheat eliminator allows heat transfer between the effluent gas delivered by the compressor at high pressure and temperature and the condensed water produced on the evaporator surface at a relatively low temperature.

In a standard condensation process that does not use an external superheat, some of the energy exchange area is to reduce the temperature of the superheated gas until the superheated gas reaches saturation conditions. The area used to carry out this process may be 10 to 20% of the total heat transfer area of the condenser. The heat load removed under these conditions is generally relatively small, due to the low heat transfer coefficient obtained in a single phase exchange process, especially when using air as the secondary cooling medium.

The use of an external superheat eliminator as described herein takes advantage of the greater heat transfer coefficient obtained by the faster condensation of the coolant because of the large temperature difference between the fluids and also because the portion of the secondary cooling medium This is because of the improvement of the heat transfer coefficient of the secondary cooling medium (water) due to the evaporation (two-phase process).

Figure 2 shows a T-S chart for an improved cycle compared to Figure 1, using an external superheat eliminator. The external overheating device can be installed just before the air cooled condenser.

Figure 2 shows the superheat removal of steam with condensed water, saturated condensation, and cold cooldown by standard heat removal for three different heat removal sub-processes: the air stream. 2 also shows the temperature profile of the air in the case of secondary cooling medium: condensed water in the case of superheat removal and in the case of condensation and cold cooling.

The superheat removal is carried out by an external superheater and the film condensation of the vapor appears almost instantaneously above the internal surface of the heat exchanger because under such conditions the heat exchanger is surrounded by condensed water at relatively low temperature conditions , The wall temperature of the superheat eliminator is much lower than the saturating temperature of the coolant.

Because the temperature of the water from the evaporator is generally the dew point temperature of the air exiting the evaporator, the heat removal process inside the superheater is driven by latent heat removal to produce sensible heat removal by steam overheating, and condensate coolant .

Additionally, when the wall temperature of the pipe is less than the saturation temperature of the coolant, additional sensible heat removal due to cooldown of the condensate can also make an important contribution to the overall heat removal process inside the superheat elimination.

On the inside of the external superheat eliminator, the temperature difference between the secondary cooling medium (condensate from the evaporator) and the bulk temperature of the coolant may be several tens of degrees. This temperature difference is considerably greater than the temperature difference observed in a typical superheat process inside a standard air source condenser (air-to-coolant bulk temperature), which may result in only a few degrees.

The fact that the condensing process can be started before the coolant enters the condenser is important in increasing the efficiency of the air source condenser because more of the area of the condenser will subsequently be intended to continue the saturated condensation process, Has a larger heat transfer coefficient between the air than the single-phase superheat removal process.

In order to allow the heat transfer process, the superheat eliminator is located in an open cavity condensate pool where low temperature water from the evaporator can fall and be in contact with the surface of the superheat eliminator, And evaporation of a portion of the water.

An exemplary embodiment of an air conditioner having such an external superheat eliminator, particularly a portable air conditioner, is shown in FIG. In Figure 3, 301 is a compressor, 302 is an air source condenser, 303 is an external superheat eliminator, 304 is a condensate pool where the superheater is located and a heat transfer process occurs, and 305 is a condensed Water pipe, and 306 is a condenser fan.

The superheat eliminator heat exchanger 303 may, in one embodiment, be disposed in the open pool 304, and in the open pool condensed water falling from the evaporator is discharged by the pipe 305. In the pool, due to the large temperature difference between both fluids, a heat exchange process occurs. As a result, while the hot gas begins to condense, a portion of the condensed water is evaporated.

The superheat eliminator section is located within the lower end side after condenser 302, which allows for proper dragging of the evaporated moisture by the air stream from the condenser. Under these conditions, the air stream flowing through the condenser has a higher temperature and a lower relative humidity, and hence the capacity to maintain the evaporated water produced in the superheater is also greater.

The design of the superheat eliminator includes a pipe heat exchanger having one or more passages mounted inside the open water pool. Further, the shape of the superheat eliminator heat exchanger 303 may be adjusted depending on the geometry and space of the air conditioning unit in which the superheat eliminator 303 is located.

Another possible variant is the use of an overheat eliminator 303, such as the use of different types of pins or inner geometry inside the pipe (a finned inner surface) to increase the heat transfer area of the superheat eliminator 303, Lt; / RTI >

Additionally, the water pool can also employ different configurations, depending on the geometry of the particular unit and the relative location of the other components in the system. In that sense, the superheat eliminator may have any other design of rectangular, cylindrical shape. Two possible options are presented in Figures 4 and 5.

Under certain humidity conditions, the superheat eliminator may not be able to remove all of the condensate generated by the evaporator. To prevent performance limitations of the water evaporation system in high humidity conditions, the system can be modified to include a water tank within the lower end of the condenser.

4, reference numeral 401 denotes a compressor, reference numeral 402 denotes an air source condenser, reference numeral 403 denotes an overheat eliminator, reference numeral 404 denotes a condensate pool, reference numeral 405 denotes a condensed water pipe from the evaporator, reference numeral 406 denotes a discharge line from the compressor, 407 is a noise insulation coat surrounding the compressor.

Figure 5 also shows possible variations that may include the possibility of using auxiliary water tanks that can store non-evaporated water in extreme humidity conditions.

5, reference numeral 501 denotes a compressor, 502 denotes a cylindrical type condenser, 503 denotes an overheat eliminator, 504 denotes a condensate pool, 505 denotes a condensed water pipe from the evaporator, 506 denotes a discharge line from the compressor, 507 is a noise insulation coat surrounding the compressor, 508 is a noise insulating material around the compressor, 509 is an auxiliary water tank for recovering unvaporized water, 510 is a base for the condenser fan, 511 is all of the system It is part of the structure that keeps the components.

According to some embodiments, the coating element may be wound around the pipe connecting the superheat eliminator to the compressor and the superheat eliminator to the condenser.

An apparatus as described herein can be configured to allow condensed water falling from an evaporator to be discharged over a pipe covered by a coating element thereby increasing the heat transfer area of the superheat eliminator, Thereby facilitating the evaporation and removal of condensed water through the hot air stream flowing therefrom.

Figure 6 shows a possible configuration of such an embodiment having a coating material on the connecting pipe.

In FIG. 6, reference numeral 601 denotes a compressor, 602 denotes an air source condenser, 603 denotes an overheat eliminator, 604 denotes a water pool, 605 denotes a condensed water pipe from the evaporator, 606 denotes a condenser fan And reference numeral 607 denotes a coating material covering the connection between the discharge pipe and the superheat eliminator and the condenser.

In Figure 6, the air stream after the condenser has a low relative humidity and a high temperature, which permits proper transport of evaporated moisture by the air stream from the condenser.

 The material of the coating element may be any natural or artificial fiber made into a flat mesh or a cylindrical shape wound around a pipe thereby enabling the temporary retention of water around the pipe during the evaporation of water do.

Alternatively to the coating element, the pipe can be coiled by a pin in the form of a spiral, which can allow the evaporation of such water by dropping cold water from the evaporator and by heat exchange with the hot surface of the pinned tube.

Figure 7 shows a possible embodiment of a coating element on the connecting pipe.

According to another embodiment, a water pump system may be added to spray the unvaporized water from the auxiliary tank to the upper end of the condenser, and at such an upper end the pumped water may fall onto the condenser surface. In such an embodiment, the non-evaporated water can continuously lower the temperature of the condenser surface and, when the coolant is saturated, the system can simultaneously pump water through the air stream across the condenser. Figure 8 shows an embodiment including an auxiliary water pumping system for removing uncondensed water.

To prevent the water droplets filling the gaps between the fins to block the air path to create additional pressure drops in the air stream and to reduce the condenser air flow, .

8, reference numeral 801 denotes a compressor, 802 denotes a condenser, 803 denotes an overheat eliminator, 804 denotes a condensate pool, 805 denotes a condensed water pipe from the evaporator, 806 denotes an auxiliary water tank, 807 denotes a water pump 808 is a water pipe from the tank to the spray system, 809 is a water spray element in the top of the condenser, and 810 is a water drainage system.

According to another embodiment, it is possible to take advantage of the low temperature of the condensed water from the evaporator to otherwise reduce the condensation pressure of the cycle. For example, such an effect may alternatively be achieved firstly by discharging the condensed water onto the condenser. The remaining unvaporized water can then be collected in a water tank, for example, located on the lower end side after the condenser, and pumped over the superheater water pool. Figure 9 illustrates an exemplary design of such an embodiment.

9, reference numeral 901 denotes a compressor, 902 denotes a condenser, 903 denotes an overheat eliminator, 904 denotes a non-evaporated water pool, 905 denotes a condensed water pipe from the evaporator, 906 denotes an auxiliary water tank, 908 is a water pipe from the tank to the superheat water pool, 909 is a condenser water spray element disposed within the upper portion of the condenser, and 910 is a non-evaporated water drain.

The difference between the embodiment of FIG. 8 and the embodiment shown in FIG. 9 is the temperature difference between the heat source and the heat sink of different heat removal subprocesses. Constructively, the version presented in FIG. 9 may have some advantages; From the energy efficiency standpoint, the embodiment shown in Fig. 8 typically exhibits a higher energy efficiency solution.

One limitation in the embodiment shown in Figure 9 is that in order to allow the bulk temperature of the coolant to be closer to the thermodynamic equilibrium before the coolant enters the condenser because the temperature difference between both fluids is small, Lt; RTI ID = 0.0 > 8 < / RTI >

The use of an air conditioner as described herein provides a practical solution for minimizing the size of air-cooled condensation that is commonly used in portable AC systems, but also for other systems that work with air as a cooling medium do.

Minimization potential of the condenser size is achieved by providing zoning of different heat exchange sub-processes. Also, overheating of the hot gas delivered by the compressor is provided.

By performing the superheat elimination process outside the condenser, typically intended area and internal volume can be reassigned for this process in order to complete the phase change process (condensation) and the subcooling inside the air-cooled condenser.

As the two phase change and cold cooling process have greater heat transfer coefficients, the total area required for the heat removal process in the condenser for a given capacity will be smaller.

As a result, for a condenser of a given size, the superheat eliminator can promote a larger enthalpy difference in the cycle, thereby providing a greater cooling capacity in a standard system without significantly affecting the power consumption of the compressor So that the cycle efficiency of the cooling cycle can also be increased.

On the other hand, the design of the superheat eliminator allows effective removal of undesirable condensed water generated in the cooling process; At the same time, the air conditioner takes advantage of the greater heat transfer coefficient obtained by evaporation of water.

An advantage of the technique described herein is that the heat removal process in the portable AC unit can be initiated prior to coolant entry into the condenser, thereby minimizing the size of a standard air cooled condenser or allowing for an increase in cooling capacity to a given condenser size It is.

The use of the method and apparatus as described herein allows for the advantage of a larger temperature difference between both flows to enable a compact and efficient design of the superheat eliminator which results in a more efficient condensation process do. This effect is achieved by increasing the heat transfer area for carrying out the two-phase process of condensation, which provides a better heat transfer coefficient and which is generally the case for a single-phase process of superheat removal in a conventional manner It is intended.

The techniques described herein may further improve the conventional methods used to remove undesirable condensed water generated in an AC system, particularly in a typical cooling process of a portable unit.

According to some embodiments, the mechanism diffuses the condensed water between the condenser rows. Through this method, the non-evaporated water is atomized into small droplets on the surface of the condenser and, accordingly, such water is removed through the air flow stream across the condenser rather than its evaporation.

The disadvantage of scattering water is that the water droplets that are transferred into the air stream can eventually flocculate or condense on the air exhaust conduit and thus fall inside the conduit system and create a water leaking problem for the user I can do it.

In addition, for improved examples of thermodynamic cycles obtained by use of the techniques described herein, particularly in the case of geometric shapes of cooling circuits with small hydraulic diameters such as small tubes or micro-channels, There is an additional advantage obtained by reducing the inner pressure drop. The smaller the pressure drop, the lower the power consumption and the more efficient the system.

Another advantage of the technique described herein is that it can increase the charge of the coolant without affecting the condensation pressure in order to increase the coolant enthalpy difference in the condenser and also in the evaporator, It will be possible to increase the capacity.

By starting the condensation process in the external superheat eliminator, the heat loss from the compressor surface is also reduced, so that the reliability of the compressor can be increased without affecting the mechanical performance of the compressor.

The design presented for the superheat eliminator has the additional advantage of preventing / reducing resonance introduced by tangential vibration due to the variable torque produced by the compressor motor.

Accordingly, in accordance with the foregoing, there is provided an alternative to the conventional method which helps to reduce the condensation temperature of the cycle in a more efficient manner. This is achieved by efficient zoning of the heat removal process using condensed water that drips from the evaporator.

Thus, a more efficient energy exchange process is performed by an external superheat eliminator installed between the compressor and the condenser. This method takes advantage of the larger temperature difference between the hot discharge gas delivered by the compressor and the condensed cold water dripping from the evaporator surface.

Claims (5)

An air conditioner comprising a compressor (301), and a condenser (302), characterized by an overheat eliminator (303) provided in a flow path from the compressor to the condenser. The method according to claim 1,
Wherein the air conditioner is a portable air conditioner. 3. The method according to claim 1 or 2,
Wherein the superheat eliminator is located within the open cavity (304). The method of claim 3,
Wherein the air conditioner is configured to supply condensed water to the open cavity. 5. The method of claim 4,
Further comprising a pipe (305) configured to direct condensed water dripping from said evaporator into said open cavity.

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