KR102538185B1 - cooling dehumidifier - Google Patents

Abstract

The cooling dehumidifier of the present invention includes a compressor for compressing a refrigerant; a main condenser that liquefies the high-temperature and high-pressure gaseous refrigerant discharged from the compressor; and an evaporator in which the refrigerant from the main condenser evaporates and cools and dehumidifies by heat exchange with air and a large temperature difference. .

Description

cooling dehumidifier {cooling dehumidifier}

The present invention relates to a cooling dehumidifier, and more particularly, to a cooling dehumidifier for low humidity using condensation heat.

A dehumidifier is an air conditioner for lowering humidity, and can lower relative humidity by directly removing moisture in the air.

Dehumidifiers remove moisture from the air in two ways: drying and cooling.

A drying type dehumidifier uses a chemical desiccant, which directly absorbs or adsorbs moisture in the air like a dehumidifying product used at home. If the desiccant does not absorb any more moisture, the desiccant can be reheated and the moisture separated at this time is released to the outside of the desiccant so that the desiccant can be used again. This method is useful for removing small amounts of moisture from confined spaces. The absorbent includes silica gel, which is a porous material having an excellent ability to adsorb moisture.

Cooling dehumidifiers control humidity by condensing water vapor in the air into water. To condense the water vapor, the temperature of the air must be lowered below the dew point. Therefore, the cooling dehumidifier uses a refrigerant for cooling.

As shown in FIG. 1, the most basic system of the conventional cooling dehumidifier includes a compressor 1 for compressing the refrigerant, a condenser 2 for liquefying the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1, and the A filter dryer (3) connected to the condenser (2) to remove moisture and impurities in the refrigerant, an expansion device (4) for adiabatically expanding the liquid refrigerant from the condenser (2), and An evaporator (5, heat exchanger) in which the refrigerant evaporates to cool and dehumidify the fluid, and a condensate discharge device (6) for discharging condensate generated in the process of cooling and dehumidifying the refrigerant in the evaporator (5) , It consists of a hot gas bypass valve (7) for freezing and load control of condensate generated in the process of cooling and dehumidifying.

Existing evaporators are divided into primary evaporators and secondary evaporators, each having its own heat exchange area. The primary evaporator pre-cools the fluid entering through the inlet through heat exchange between the high-temperature fluid entering through the inlet and the fluid cooled by the refrigerant in the secondary evaporator and exiting through the outlet, thereby reducing the cooling capacity of the secondary evaporator and refrigerant compressor serves to reduce the capacity of In the secondary evaporator, the refrigerant entered through the expansion device is evaporated, and in this process, the pre-cooled fluid is cooled and dehumidified while passing through the primary evaporator. The fluid cooled and dehumidified in the secondary evaporator flows through the primary evaporator and exchanges heat with the high-temperature fluid entering through the primary evaporator inlet, undergoes a reheating process in which the temperature rises, and is discharged in a dry state. From the inlet of the evaporator, the fluid goes through a series of processes of pre-cooling, cooling and dehumidification, and reheating, and many methods have been proposed to increase heat exchange efficiency in this process.

In addition, in the prior art, for cooling and dehumidification, air is passed through an evaporator (heat exchanger) under conditions of a dew point temperature or less to cool and remove moisture. The moisture content at this time is 40 to 45% relative humidity based on 23 ℃. For specifications with lower relative humidity, additional evaporators (heat exchangers) are installed (primary, secondary series type) and piping configurations increase according to the increase in load, and operation is difficult due to various problems such as frost problems and load fluctuations. It's a difficult situation. Therefore, it is being used in a stable operating range (23 ℃, 45%) or by applying mechanical valves (hot gas bypass, EPR, etc.) to solve the problem inefficiently.

Moreover, in the case of the frost problem, it occurs on the evaporator side according to load fluctuations (low temperature or humidity) or design specifications when cooling air. If ice forms on the surface, the cooling capacity is reduced, and if not resolved in a timely manner, the size of the ice gradually increases, blocking the air flow path or causing damage to the evaporator due to volume expansion. Therefore, in the past, various methods such as reverse cycle operation, hot gas defrost, electric heater, and water spray have been used to achieve defrost. Although the above methods can effectively defrost, it is difficult to operate the system consistently and normally for a long time because it causes frequent changes in the cycle.

In other words, the existing cooling dehumidifier is designed to dehumidify the air passing through the evaporator at a dew point temperature of about 8 to 10 ° C. In the conditions below this, the form of bypassing the hot gas is applied or the form of repeating the frosting / defrosting operation is being used because of the problem of frosting. These problems can cause problems in the durability of the driving unit through energy loss and repeated operation/stop.

Therefore, there is a demand for the development of a cooling dehumidifier that solves fundamental problems and improves dehumidification performance through capacity variation and precise control of refrigerant cycles.

Registered Patent Publication No. 1110049 (2012.02.15. Notice) Patent Publication No. 2015-0072598 (published on June 30, 2015) Patent Publication No. 2020-0017081 (2020.02.18. Publication)

The present invention has been made to solve the above-mentioned problems of the related art, and an object of the present invention is to provide a cooling dehumidifier capable of operating stably at all times at a lower absolute humidity than conventional cooling and dehumidifying technology.

The cooling dehumidifier of the present invention for achieving the above object includes a compressor for compressing a refrigerant; a main condenser that liquefies the high-temperature and high-pressure gaseous refrigerant discharged from the compressor; and an evaporator in which the refrigerant from the main condenser evaporates and cools and dehumidifies by heat exchange with air and a large temperature difference. .

In addition, the evaporator is characterized in that it consists of a first evaporator of the co-current type in which the flow of air and refrigerant is the same, and a second evaporator of the counter-current type in which the flow of air and the refrigerant is opposite to each other by receiving the refrigerant passing through the first evaporator.

In addition, a mixing chamber is provided between the first evaporator and the second evaporator.

In addition, a primary three-way valve for bypassing the high-pressure refrigerant passing through the compressor to the rear end of the condenser is further provided.

In addition, a second three-way valve bypassing the high-pressure refrigerant passing through the compressor to an evaporator and a reheater (auxiliary condenser) is further provided.

In addition, an EEV that controls low pressure through load compensation by utilizing the high-pressure refrigerant bypassed by the secondary three-way valve is further provided.

The cooling dehumidifier according to the present invention can expect the effect of fundamentally solving the conventional problems.

First, it is an evaporator design for effective large-temperature difference heat exchange on the air side. In general, evaporators are designed and used with a temperature difference of 10 to 12 ° C based on a single coil, but in the present invention, a plurality of coils are combined with primary co-current and secondary counter-current and processed in a single cycle. Due to this, as the heat exchange rate increases, the piping configuration becomes simple and a plurality of effects can be produced in a single cycle.

In addition, it is possible to solve the problem of ice formation on the evaporator side through a design capable of improving the heat exchange rate and setting the degree of superheat low.

Second, it is possible to maintain a constant high-pressure side pressure through precise hot gas flow distribution with an electronic three-way valve, thereby maintaining a constant compression ratio without being affected by the environment (outside air). Therefore, cycle stability and product reliability can be improved.

Third, an optimal complex control logic was constructed to prevent frost on the evaporator side.

During air cooling, if the temperature difference between the inlet and outlet is large or the load on the evaporator side is reduced, the evaporation temperature is lowered to control the superheat and the surface of the coil freezes. In order to fundamentally solve this problem, a control method reflecting various variables was devised. First of all, if the air is cooled below the target temperature, the controller determines this and reduces the operation rate of the compressor to the minimum operating range. If it is still low, the hot gas bypasses the evaporator side to compensate for the load. At this time, for an auxiliary stable refrigeration cycle, the temperature and pressure on the refrigerant side are detected, and the envelope control (pressure control through compressor and expansion valve control) is performed by applying the upper/lower limit values calculated from the test data. As a result, it is possible to drive with optimum performance in a range that does not freeze.

1 is a flowchart illustrating a dehumidification system of a conventional cooling dehumidifier.
2 is a configuration diagram showing a cooling dehumidifier according to the present invention.
Figure 3 is a view showing the evaporator of Figure 2;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a configuration diagram showing a cooling dehumidifier according to the present invention, and FIG. 3 is a diagram showing the evaporator of FIG. 2 .

As shown in FIGS. 2 and 3, the cooling dehumidifier (A) according to the present invention includes a compressor 100 for compressing a refrigerant, and a main condenser for liquefying the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 100. 200 and an evaporator 300 in which the refrigerant from the main condenser 200 evaporates and cools and dehumidifies by heat exchange with air and a large temperature difference.

At this time, the evaporator 300 is composed of a single cycle in which primary co-current and secondary counter-current are simultaneously performed.

Specifically, as shown in FIG. 3, the evaporator 300 receives the first evaporator 310, which is a co-current type in which the flow of air and refrigerant is the same, and the refrigerant that has passed through the first evaporator 310, so that the flow of air and refrigerant is It is composed of a second evaporator 320 of countercurrent type.

Here, since the first and second evaporators 310 and 320 are integrally configured with a well-known co-current heat exchanger and a counter-current heat exchanger, a detailed description of their operation will be omitted.

In addition, a mixing chamber 330 is provided between the first evaporator 310 and the second evaporator 320 .

That is, although the first evaporator 310 and the second evaporator 320 are a single refrigerant cycle, the ratio of bypassed cooling air is reduced by dividing the evaporator into two and providing a space in the form of a mixing chamber 330 in the middle.

Accordingly, a plurality of coils are processed in a single cycle by combining the first co-current and the second counter-current. As a result, as the heat exchange rate increases, the piping configuration becomes simpler and a plurality of effects can be produced in a single cycle.

In addition, it is possible to solve the problem of ice formation on the evaporator side through a design capable of improving the heat exchange rate and setting the degree of superheat low.

Also, a primary three-way valve 400 bypassing the high-pressure refrigerant passing through the compressor 100 to a rear end of the condenser 200 is further provided.

That is, the primary three-way valve 400 is an electronic three-way valve that can maintain a constant high-pressure side pressure through precise high-pressure refrigerant (hot gas) flow distribution, thereby maintaining a constant compression ratio without being affected by the environment (outside air). can keep Therefore, cycle stability and product reliability can be improved.

Meanwhile, an auxiliary condenser 500 is further provided to heat supercooled air for dehumidification with sensible heat + latent heat of the high-pressure refrigerant (hot gas) by branching the high-pressure refrigerant (hot gas) from the outdoor unit side. That is, energy is saved through the recycling of condensation heat that is thrown away outdoors.

In addition, on the other hand, a secondary three-way valve 600 bypassing the high-pressure refrigerant passing through the compressor 100 to the evaporator 300 is further provided.

The secondary three-way valve 600 primarily heats the supercooled air in the auxiliary condenser 500 using the high-pressure refrigerant (hot gas) of the compressor 100. At this time, the secondary three-way valve 600 is PID control is performed so that the supercooled air reaches the set temperature by precisely adjusting the flow rate of (hot gas).

In addition, the high-pressure refrigerant (hot gas) branched from the secondary three-way valve 600 is a high-pressure refrigerant (hot gas) when the load is insufficient despite the minimum RPS operation of the BLDC compressor through the EEV (610, electronic expansion valve) for low pressure compensation. hot gas) is injected into the front of the evaporator to simultaneously perform the roles of low pressure compensation and anti-icing.

In addition, an electric heater 101 that finally controls the temperature when the auxiliary condenser 500 is out of the controllable heating range is further provided.

Meanwhile, a fan 102 circulating humidity-adjusted air to the target space is further provided.

In addition, an indoor unit solenoid valve 103 is further provided to block the refrigerant when the auxiliary condenser 500 is not in use.

In addition, a main EEV (electronic expansion valve) 104 for controlling the flow rate of the refrigerant passing through the main condenser 200 to control the degree of superheat is further provided.

On the other hand, a sight glass 105 displaying the refrigerant flow state and the moisture state contained in the refrigerant is further provided.

In addition, an oil separator (106, oil separator) for separating oil from the refrigerant discharged to the compressor and returning it to the compressor is further provided.

In addition, an accumulator 107 is further provided to separate the liquid and gas contained in the refrigerant and inhale only the gas.

Meanwhile, an outdoor unit solenoid valve 108 is further provided to block circulation of indoor/outdoor air when the outdoor unit is stopped for a long time or when the pump is down.

In addition, a receiver 109 serving as a buffer for storing surplus refrigerant when the amount of circulating refrigerant changes is further provided.

And, a filter dryer (110, filter dryer) serving as a filter for filtering out moisture and foreign substances contained in the pipe is further provided.

According to the present invention, first, an evaporator is designed for effective large temperature difference heat exchange on the air side. In general, evaporators are designed and used with a temperature difference of 10 to 12 ° C based on a single coil, but in the evaporator 300 composed of the first and second evaporators 310 and 320 of the present invention, a plurality of coils are combined in primary co-current and secondary counter-current. and processed in a single cycle. As a result, as the heat exchange rate increases, the piping configuration becomes simpler and a plurality of effects can be produced in a single cycle.

In addition, it is possible to solve the problem of ice formation on the evaporator side through a design capable of improving the heat exchange rate and setting the degree of superheat low.

Second, it is possible to maintain a constant high-pressure side pressure through precise high-pressure refrigerant (hot gas) flow distribution with the primary three-way valve 400, thereby maintaining a constant compression ratio without being affected by the environment (outside air). Therefore, cycle stability and product reliability can be improved.

Third, an optimal complex control logic was constructed to prevent frost on the evaporator side.

During air cooling, if the temperature difference between the inlet and outlet is large or the load on the evaporator side is reduced, the evaporation temperature is lowered to control the superheat and the surface of the coil freezes. In order to fundamentally solve this problem, a control method reflecting various variables was devised. First of all, if the air is cooled below the target temperature, the controller determines this and reduces the operation rate of the compressor to the minimum operating range. If it is still low, the high-pressure refrigerant (hot gas) is bypassed through the secondary three-way valve 600 and the EEV 610 on the evaporator side to compensate for the load. At this time, for an auxiliary stable refrigeration cycle, the temperature and pressure on the refrigerant side are detected, and the envelope control (pressure control through compressor and expansion valve control) is performed by applying the upper/lower limit values calculated from the test data. As a result, it is possible to drive with optimal performance in a range that does not freeze.

The operation of the cooling dehumidifier of the present invention will be described.

First, the cooling and dehumidifying operation is started. At this time, the fan 102 of the indoor unit is driven.

And, if the temperature/humidity is higher than the set value, the outdoor unit operates.

Next, the outdoor unit solenoid valve 108 opens and the compressor 100 operates.

At this time, the number of rotations of the compressor (cooling capacity) is PID controlled by the error between the current temperature/humidity and the set value.

In addition, after primary cooling in the first evaporator 310 , secondary (final) cooling is performed in the second evaporator 320 . At this time, the maximum capacity is possible to cool and dehumidify up to the dew point temperature of 4℃ (23℃, R.H30%).

Next, after processing the sensible heat load or water removal through the evaporator 300, the supercooled air is heated through the auxiliary condenser 500 and the electric heater, and supplied to the target space.

In addition, the FAN of the main condenser 200 and the primary three-way valve 400 are controlled to control the high pressure on the refrigerant side. The fan of the condenser starts operation at the minimum rps when the refrigerant set pressure of 26 bar is reached, and proportional control is performed to match the operating pressure with the set pressure. It is bypassed and used to maintain the pressure in the high-pressure part. At this time, to maintain the high-pressure set value, the step motor of the primary three-way valve adjusts the opening through PID control to control the (high-pressure refrigerant) hot gas flow rate.

Next, the supercooled air is primarily heated in the auxiliary condenser 500 using the high-pressure refrigerant (hot gas), and the secondary three-way valve 600 precisely controls the flow rate of the high-pressure refrigerant (hot gas) to cool the supercooled air PID control is performed to reach the set temperature.

At this time, the high-pressure refrigerant (hot gas) additionally branched from the secondary three-way valve 600 is loaded through the EEV (610, electronic expansion valve) for low pressure compensation despite the minimum RPS operation of the BLDC compressor 100. When insufficient, high-pressure refrigerant (hot gas) is injected into the front end of the evaporator 300 to simultaneously perform the role of low-pressure compensation and anti-icing.

Expected effects by the present invention are as follows.

First, through the cooling and dehumidification of the simple direct cooling system, air conditioning is possible with a lower humidity than the conventional method. Various methods can be configured to reduce the relative humidity, such as applying additional utilities or alternating operation of the system. However, since this method incurs additional energy and cost, assuming that it is a different case, the invention has improved performance through an advanced technology.

Second, the air conditioning environment for moisture management is becoming increasingly important along with cleanliness in processes such as secondary batteries and semiconductor markets. In this special dehumidification, a post-treatment utility such as silica gel is applied after pretreatment (cooling and dehumidification), and the important part at this time is the cooling and dehumidification part. This is because the more moisture content is removed in the pretreatment, the lower the dew point temperature can be reached. Therefore, since cooling and dehumidification performance is a key point of special dehumidification, the corresponding invention can serve as a basis for special dehumidification in the future.

In the above, the preferred embodiments of the present invention have been described in detail, but the technical scope of the present invention is not limited to the above-described embodiments and should be interpreted according to the claims. At this time, those skilled in the art should consider that many modifications and variations are possible without departing from the scope of the present invention.

A - Cooling dehumidifier 100 - Compressor
200 - main condenser 300 - evaporator
310 - first evaporator 320 - second evaporator

Claims (6)

A compressor that compresses the refrigerant;
a main condenser that liquefies the high-temperature and high-pressure gaseous refrigerant discharged from the compressor; and
An evaporator in which the refrigerant from the main condenser evaporates and cools and dehumidifies by heat exchange with air and a large temperature difference;
The evaporator is characterized in that it is composed of a single cycle in which the first co-current and the second counter-current are simultaneously performed,
The evaporator further includes a first evaporator of the co-current type in which air and refrigerant flow is the same and a second evaporator of the counter-current type in which the flow of air and refrigerant is opposite by receiving the refrigerant passing through the first evaporator,
Further comprising a mixing chamber provided between the first evaporator and the second evaporator,
The mixing chamber further includes providing a chamber-shaped space between the first evaporator and the second evaporator,
Further comprising a primary three-way valve bypassing the high-pressure refrigerant passing through the compressor to the rear end of the condenser,
Further comprising a secondary three-way valve for bypassing the high-pressure refrigerant passing through the compressor to an evaporator and an auxiliary condenser,
Including that an EEV that uses the high-pressure refrigerant bypassed by the secondary three-way valve to control low pressure through load compensation is further provided,
Further comprising an electric heater to finally control the temperature when the auxiliary condenser is out of the controllable heating range,
The cooling dehumidifier further comprising an indoor unit solenoid valve for shutting off the refrigerant when the auxiliary condenser is not in use. delete delete delete delete delete

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