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Title:
THERMOHYGROSTAT EMPLOYING HEAT PUMP
Document Type and Number:
WIPO Patent Application WO/2008/030008
Kind Code:
A1
Abstract:
A thermo-hygrostat according to the present invention comprises: an indoor unit having an expansion valve, an evaporator, a recycling condenser, a humidifying unit, a receiver tank, a fan, a plurality of solenoid valve, and a check valve; an outdoor unit having an accumulator, a compressor, an heat exchanger (operating as a condenser or a evaporator), a fan, a super cooling-heating device, and an expansion valve; a refrigerant-supplying conduit; and a refrigerant -returning conduit.

Inventors:
HWANG, Dosub (2 Floor, 1123-28 Hwagok 6-dong, Gangseo-gu, Seoul 157-928, KR)
HWANG, Daeseob (301-ho, Ga-dong shinyonhee house,645-14, Deungchon-dong, Gangseo-gu, Seoul 157-030, KR)
Application Number:
KR2007/004124
Publication Date:
March 13, 2008
Filing Date:
August 28, 2007
Export Citation:
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Assignee:
HWANG, Dosub (2 Floor, 1123-28 Hwagok 6-dong, Gangseo-gu, Seoul 157-928, KR)
HWANG, Daeseob (301-ho, Ga-dong shinyonhee house,645-14, Deungchon-dong, Gangseo-gu, Seoul 157-030, KR)
International Classes:
F25B30/00
Foreign References:
KR20050080149A2005-08-11
JP2004317091A2004-11-11
JPH06347107A1994-12-20
Attorney, Agent or Firm:
HWANG, Ilseok (Well International Patent Office, 2 Floor Yale Building, 898-16,Daechi-dong, Gangnam-gu, Seoul 135-840, KR)
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Claims:

Claims

[1] An air cooled thermo-hygrostat employing a heat pump, the air cooled thermo- hygrostat comprising: an indoor unit 10, which includes expansion valves EXl and EX 2 which adia- batically expand a high temperature and pressure liquid refrigerant into a low temperature and pressure refrigerant, an evaporator 11 for evaporating the refrigerant that has passed through the expansion valves EXl and EX2 through heat-exchange between the refrigerant and air, a reheating condenser 12, which allows the high temperature and pressure liquid refrigerant to selectively flow therethrough so as to heat and dehumidify the air, which has been cooled by the heat-exchange with the refrigerant while passing through the evaporator 11, and controls a temperature and humidity of the air through the heat-exchange between the high temperature and pressure liquid refrigerant and the air, a humidifier 13, which stores water therein and allows the high temperature and pressure liquid refrigerant to selectively flow therethrough such that the stored water is evaporated by the high temperature and pressure liquid refrigerant, a receiver 16, which sends the liquid refrigerant to the expansion valves EXl and EX2, a blower 17, which circulates the air through the evaporator 11, the reheating condenser 12 and the humidifier 13 such that the air is fed into an indoor room, and solenoid valves SV6, SVlO and SVl 1 and a check valve CW that allow the high temperature and pressure refrigerant to flow only into the reheating condenser 12 or to flow into the reheating condenser 12 and the humidifier 13 during a heating operation; an outdoor unit 20, which includes a liquid separator ACC, which separates refrigerant liquid from refrigerant gas, which is lowered in pressure while passing through the evaporator 11 of the indoor unit 10 during a cooling operation and separates refrigerant liquid from refrigerant gas, which is super-heated by a super cooling and super heating unit SRH during the heating operation, compressors COMl and COM2, which compress the refrigerant gas introduced from the liquid separator ACC such that refrigerant gas has a high temperature and pressure, a condenser-evaporator 21, which condenses the refrigerant gas introduced from the compressors COMl and COM2 to make a high temperature and pressure liquid refrigerant during the cooling operation and evaporate the refrigerant, which has a temperature lower than a temperature of an external air, through heat-exchange between the refrigerant and the air during the heating operation, a propeller fan 22, which allows the air to flow into the condenser- evaporator 21, the super cooling and super heating unit SRH, which performs a

super cooling operation and a super heating operation relative to the high pressure liquid refrigerant introduced from the indoor unit and the low temperature and pressure refrigerant gas introduced from the condenser- evaporator 21 during a heating operation, and an expansion valve EX3, which expands the refrigerant, which is super-cooled by the super cooling and super heating unit SRH, such that the refrigerant has a temperature lower than a temperature of the external air, and sends the refrigerant to the condenser- evaporator 21; and a refrigerant supply pipe 31 and a refrigerant return pipe 32 that connect the indoor unit 10 and the outdoor unit 20 to transfer the refrigerant between the indoor unit 10 and the outdoor unit 20.

[2] The air cooled thermo-hygrostat as claimed in claim 1, wherein the outdoor unit

20 includes two compressors COMl and COM2, two condenser-evaporators 21 and two propeller fans 22 that are disposed in parallel, respectively, and are integrally formed.

[3] The air cooled thermo-hygrostat as claimed in claim 1, wherein the outdoor unit

20 includes two compressors COMl and COM2, two condenser-evaporators 21 and two propeller fans 22 that are disposed in parallel, respectively, and are separately formed.

[4] A water cooled thermo-hygrostat employing a heat pump, the water cooled thermo-hygrostat comprising: an indoor unit 10', which includes expansion valves EXl and EX 2 which adia- batically expand a high temperature and pressure liquid refrigerant into a low temperature and pressure refrigerant, an evaporator 11 for evaporating the refrigerant that has passed through the expansion valves EXl and EX2 through a heat-exchange between the refrigerant and air, a reheating condenser 12, which allows the high temperature and pressure liquid refrigerant to selectively flow therethrough so as to heat and dehumidify the air, which has been cooled by the heat-exchange with the refrigerant while passing through the evaporator 11, and controls the temperature of the air through the heat exchange between the high temperature and pressure liquid refrigerant and the air, a humidifier 13, which stores a water therein and allows the high temperature and pressure liquid refrigerant to selectively flow therethrough such that the stored water is evaporated by the high temperature and pressure liquid refrigerant, a receiver 16 which sends the liquid refrigerant into the expansion valves EXl and EX2, a blower 17, which circulates the air through the evaporator 11, the reheating condenser 12 and the humidifier 13 such that the air is fed into an indoor room, and solenoid valves SV6, SVlO and SVl 1 and a check valve CW that allow the high

temperature and pressure refrigerant to flow only into the reheating condenser 12 or to flow into the reheating condenser 12 and the humidifier 13 during a heating operation, a liquid separator ACC, which separates refrigerant liquid from refrigerant gas, which is lowered in pressure while passing through the evaporator 11 of the indoor unit 10 during a cooling operation and separates refrigerant liquid from refrigerant gas which is super-heated by a super cooling and super heating unit SRH during the heating operation, compressors COMl and COM2, which compress the refrigerant gas introduced from the liquid separator ACC such that the refrigerant gas has a high temperature and pressure, a water cooled heat exchanger 40, which condenses the refrigerant gas introduced from the compressors COMl and COM2 to make a high temperature and pressure liquid refrigerant during the cooling operation and evaporates the refrigerant, which has a temperature lower than a temperature of an external air through heat exchange with a cooling water during the heating operation, the super cooling and super heating unit SRH, which performs a super cooling operation and a super heating operation relative to the high pressure liquid refrigerant introduced from the indoor unit and the low temperature and pressure refrigerant gas introduced from the water cooled heat exchanger 40 during a heating operation, and an expansion valve EX3, which expands the refrigerant, which is super-cooled by the super cooling and super heating unit SRH such that the refrigerant has a temperature lower than a temperature of an external air, and then sends the refrigerant to the water cooled heat exchanger 40; an outdoor unit 20' which includes a cooling water coil 21'which cools a cooling water and a propeller fan 22 which allows the air to flow on the cooling water coil 21';and a cooling water pipe 41 which connects the water cooled heat exchanger 40 of the indoor unit 10'and the cooling water coil 21'of the outdoor unit 20', and a cooling water circulating pump 42 disposed on the cooling water pipe 41.

Description:

Description THERMOHYGROSTAT EMPLOYING HEAT PUMP

Technical Field

[1] The present invention relates to an air cooled and water cooled thermo-hygrostat employing a heat pump, capable of maintaining the temperature and the humidity of an indoor at a constant state regardless of seasonal variation. More particularly, the present invention relates to an air cooled and water cooled thermo-hygrostat employing a heat pump for saving energy, in which a heat pump type compressor-freezer provides superior cooling and reheating functions during a summer season and provides humidifying and heating functions during a winter season without using an additional electric heater providing the heating, reheating or humidifying functions, thereby remarkably reducing energy consumption.

[2]

Background Art

[3] In order to prevent a malfunction from occurring in computer systems, which are sensitive to temperature and humidity variations and installed in a computer center, a communication laboratory, a precision measurement laboratory, a document storing room and a library, the indoor temperature and humidity must be maintained at a predetermined level. In addition, in order to improve the quality of products and decrease the error rate in various industrial fields, such as semiconductor, electronic, pharmaceutical, chemical, textile, paper and pulp manufacturing fields, the interior of the factory must be maintained in a predetermined range of temperature and humidity corresponding to the product characteristics.

[4] In general, a conventional thermo-hygrostat includes a compressor-freezer having a cooling function, an electric heater type reheating coil providing a temperature compensating function and a dehumidifying function during a summer season, and an electric heater type humidifier employing an electrode rod for maintaining the indoor humidity at a predetermined level during a winter season.

[5] During seasons between the summer and winter seasons (that is, spring and autumn), an external air load is lowered , so that the thermo-hygrostat provides only a cooling function at a low cooling capacity and the operation rate is lowered, thereby reducing energy consumption. In addition, during the summer season, a latent heat load and a dehumidifying load of external air are increased due to the cooling function, so that the energy consumption is increased.

[6] During the winter season, the external air load is greatly increased due to the

external air of the sub-zero temperature, so that the thermo-hygrostat provides the humidifying function and the heating function. In this case, the electric heater type reheating coil operates for the heating function and the electric heater type humidifier operates for the humidifying function, so that the electric energy consumption is significantly increased, thereby causing great energy consumption.

[7] However, the conventional thermo-hygrostat has disadvantageous aspects in terms of energy consumption, thereby increasing management costs. In addition, in the electric heater type humidifier employing the electrode rod, since the surface temperature of the electric heater is high, property of mineral matters in water is changed, so that a scale is generated, causing damage to the heater. In this case, the heater must be frequently exchanged or repaired. Further, a short circuit may occur due to the scale, lowering the durability of the thermo-hygrostat. For this reason, components of the thermo-hygrostat must be replaced whenever the winter season ends.

[8]

Disclosure of Invention Technical Problem

[9] The embodiment provides an air cooled thermo-hygrostat employing a heat pump, in which a heat pump type compressor-freezer performs the temperature compensating function and the dehumidifying function during the summer season without using an electric heater type reheating coil and performs the humidifying function so as to maintain the indoor humidity at a proper level during the winter season without using an electric heater type humidifier employing an electrode rod, so that energy consumption can be minimized in the summer season and winter season. In addition, in the winter season, the air cooled thermo-hygrostat employing the heat pump for saving an energy absorbs heat from cold air to use the external energy for the dehumidifying, heating and humidifying functions, so that an additional electric energy is not necessary for the dehumidifying, heating and humidifying functions, thereby remarkably reducing the operational cost and preventing energy loss.

[10] In addition, the present embodiment provides a water cooled thermo-hygrostat employing a heat pump, which performs all the functions of the air cooled thermo- hygrostat described above and is applicable for a field where the thermo-hygrostat having large capacity is installed and for a field where the distance between an indoor unit and an outdoor unit is too long to employ the air cooled thermo-hygrostat.

[H]

Technical Solution

[12] An air cooled thermo-hygrostat employing a heat pump according to the

embodiment comprises an indoor unit, which includes expansion valves EXl and EX 2 which adiabatically expand a high temperature and pressure liquid refrigerant into a low temperature and pressure refrigerant, an evaporator for evaporating the refrigerant that has passed through the expansion valves EXl and EX2 through heat- exchange between the refrigerant and air, a reheating condenser, which allows the high temperature and pressure liquid refrigerant to selectively flow therethrough so as to heat and dehumidify the air, which has been cooled by the heat-exchange with the refrigerant while passing through the evaporator, and controls a temperature and humidity of the air through the heat exchange between the high temperature and pressure liquid refrigerant and the air, a humidifier, which stores water therein and allows the high temperature and pressure liquid refrigerant to selectively flow therethrough such that the stored water is evaporated by the high temperature and pressure liquid refrigerant, a receiver, which sends the liquid refrigerant to the expansion valves EXl and EX2, a blower, which circulates the air through the evaporator, the reheating condenser and the humidifier such that the air is fed into an indoor room, and solenoid valves SV6, SVlO and SVl 1 and a check valve CW that allow the high temperature and pressure refrigerant to flow only into the reheating condenser or to flow into the reheating condenser and the humidifier during a heating operation; an outdoor unit, which includes a liquid separator ACC, which separates refrigerant liquid from refrigerant gas, which is lowered in pressure while passing through the evaporator of the indoor unit during a cooling operation and separates refrigerant liquid from refrigerant gas, which is super-heated by a super cooling and super heating unit SRH during the heating operation, compressors COMl and COM2, which compress the refrigerant gas introduced from the liquid separator ACC such that refrigerant gas has a high temperature and pressure, a condenser-evaporator, which condenses the refrigerant gas introduced from the compressors COMl and COM2 to make a high temperature and pressure liquid refrigerant during the cooling operation and evaporate the refrigerant, which has a temperature lower than a temperature of an external air, through heat exchange with the air during the heating operation, a propeller fan, which allows the air to flow into the condenser and evaporator, the super cooling and super heating unit SRH, which performs a super cooling operation and a super heating operation relative to the high pressure liquid refrigerant introduced from the indoor unit and the low temperature and pressure refrigerant gas introduced from the condenser and evaporator during a heating operation, and an expansion valve EX3, which expands the refrigerant, which is super-cooled by the super cooling and super heating unit SRH, such that the refrigerant has a temperature lower than a temperature of the external air, and sends the refrigerant to the condenser and evaporator; and a refrigerant supply pipe and a refrigerant return pipe that connect the indoor unit and the

outdoor unit to transfer the refrigerant between the indoor unit and the outdoor unit.

[13] The outdoor unit includes two compressors COMl and COM2, two condensers and evaporators and two propeller fans that are disposed in parallel, respectively, and are integrally formed.

[14] The outdoor unit includes two compressors COMl and COM2, two condensers and evaporators and two propeller fans that are disposed in parallel, respectively, and are separately formed.

[15] A water cooled thermo-hygrostat employing a heat pump comprises

[16] an indoor unit, which includes expansion valves EXl and EX 2 which adiabatically expand a high temperature and pressure liquid refrigerant into a low temperature and pressure refrigerant, an evaporator for evaporating the refrigerant that has passed through the expansion valves EXl and EX2 through a heat-exchange between the refrigerant and air, a reheating condenser, which allows the high temperature and pressure liquid refrigerant to selectively flow therethrough so as to heat and dehumidify the air, which has been cooled by the heat-exchange with the refrigerant while passing through the evaporator, and controls the temperature of the air through the heat exchange between the high temperature and pressure liquid refrigerant and the air, a humidifier, which stores a water therein and allows the high temperature and pressure liquid refrigerant to selectively flow therethrough such that the stored water is evaporated by the high temperature and pressure liquid refrigerant, a receiver which sends the liquid refrigerant into the expansion valves EXl and EX2, a blower, which circulates the air through the evaporator, the reheating condenser and the humidifier such that the air is fed into an indoor room and solenoid valves SV6, SVlO and SVl 1 and a check valve CW that allow the high temperature and pressure refrigerant to flow only into the reheating condenser or to flow into the reheating condenser and the humidifier during a heating operation, a liquid separator ACC, which separates refrigerant liquid from refrigerant gas, which is lowered in pressure while passing through the evaporator of the indoor unit during a cooling operation and separates refrigerant liquid from refrigerant gas which is super-heated by a super cooling and super heating unit SRH during the heating operation, compressors COMl and COM2, which compress the refrigerant gas introduced from the liquid separator ACC such that the refrigerant gas has a high temperature and pressure, a water cooled heat exchanger, which condenses the refrigerant gas introduced from the compressors COMl and COM2 to make a high temperature and pressure liquid refrigerant during the cooling operation and evaporates the refrigerant, which has a temperature lower than a temperature of an external air, through heat exchange with a cooling water during the heating operation, the super cooling and super heating unit SRH, which performs a super cooling operation and a super heating operation relative to the high pressure

liquid refrigerant introduced from the indoor unit and the low temperature and pressure refrigerant gas introduced from the water cooled heat exchanger during a heating operation, and an expansion valve EX3, which expands the refrigerant, which is supercooled by the super cooling and super heating unit SRH such that the refrigerant has a temperature lower than a temperature of an external air, and then sends the refrigerant to the water cooled heat exchanger; an outdoor unit which includes a cooling water coil which cools a cooling water and a propeller fan which allows the air to flow on the cooling water coil; and a cooling water pipe which connects the water cooled heat exchanger of the indoor unit and the cooling water coil of the outdoor unit, and a cooling water circulating pump disposed on the cooling water pipe. [17]

Advantageous Effects

[18] As described above, the present invention provides the air cooled thermo-hygrostat employing the heat pump, in which the heat pump type compressor-freezer performs the temperature compensating function and the dehumidifying function during the summer season without using the electric heater type reheating coil and performs the humidifying function during the winter season so as to maintain the indoor humidity at a proper level without using the electric heater type humidifier employing the electric rod, thereby minimizing the energy consumption during the summer season and the winter season. In addition, the air cooled thermo-hygrostat employing the heat pump absorbs the heat from the cold external air during the winter season and uses the external energy for the dehumidifying and heating functions and the regular humidifying function without using the additional electric energy, so that the operational cost and energy loss are significantly reduced.

[19] The water cooled thermo-hygrostat has all the functions of the air cooled thermo- hygrostat and is applicable for the field where the thermo-hygrostat has a large capacity and the field where the length of the refrigerant pipe between the indoor unit and the outdoor unit is too long to employ the air cooled thermo-hygrostat.

[20]

Brief Description of the Drawings

[21] FIG. 1 is a view representing the structure of an air cooled thermo-hygrostat employing a heat pump for saving an energy according to an embodiment of the present invention;

[22] FIG. 2 is a view representing a refrigerant cycle of the air cooled thermo-hygrostat employing the heat pump according to the present invention during a cooling operation;

[23] FIG. 3 is a view representing a refrigerant cycle of the air cooled thermo-hygrostat

employing the heat pump according to the present invention during a cooling and de- humidifying operation;

[24] FIG. 4 is a view representing a refrigerant cycle of the air cooled thermo-hygrostat employing the heat pump according to the present invention during a heating operation;

[25] FIG. 5 is a view representing a refrigerant cycle of the air cooled thermo-hygrostat employing the heat pump according to the present invention during a humidifying and heating operation;

[26] FIG. 6 is a view representing the structure of an integral type outdoor unit convertible into an evaporator and a condenser in the air cooled thermo-hygrostat employing the heat pump according to the present invention;

[27] FIG. 7 is a view representing the structure of a separation type outdoor unit convertible into an evaporator and a condenser in the air cooled thermo-hygrostat employing the heat pump according to the present invention; and

[28] FIG. 8 is a view representing the structure of a water cooled thermo-hygrostat employing a heat pump for saving an energy according to another embodiment of the present invention.

[29]

Mode for the Invention

[30] Hereinafter, the preferred embodiment of the present invention will be described with reference to accompanying drawings.

[31] FIGS. 1 to 5 are views representing a structure of an air cooled thermo-hygrostat employing a heat pump according to the present invention. An air cooled thermo- hygrostat employing a heat pump includes an indoor unit 10 and an outdoor unit 20. The indoor unit 10 is installed inside a thermo-hygrostat room and the outside unit 20 is installed outside a building. A refrigerant supply tube 31 and a refrigerant return tube 32 connect the indoor unit 10 and the outdoor unit 20 to each other to transfer a refrigerant between the indoor unit 10 and the outdoor unit 20, so that the temperature and humidity conditions are maintained.

[32] The indoor unit 10 includes expansion valves EXl and EX2 that adiabatically expand a high temperature and pressure liquid refrigerant into a low temperature and pressure refrigerant, an evaporator 11, which evaporates the refrigerant that has passed through the expansion valves EXl and EX2 through a heat exchange between the refrigerant and the air, a reheating condenser 12, which allows the high temperature and pressure liquid refrigerant selectively to flow therethrough so as to heat and dehumidify the air, which is cooled through the heat-exchange with the refrigerant while passing through the evaporator 11 and controls the temperature and humidity of

the air through the heat-exchange between the high temperature and pressure liquid refrigerant and the air, a humidifier 13, which stores water therein, allows the high temperature and pressure liquid refrigerant selectively to pass therethrough and evaporates the stored water using the high temperature and pressure liquid refrigerant, a receiver 16 which simply sends the liquid refrigerant to the expansion valves EXl and EX2, a blower 17 which circulates the air through the evaporator 11, the reheating condenser 12 and the humidifier 13 such that the air is fed into an indoor room, solenoid valves SV6, SW and SVl 1 and a check valve CW that allow the high temperature and pressure liquid refrigerant exclusively to flow into the reheating condenser 12 or to flow into the reheating condenser 12 and the humidifier 13 during a heating operation.

[33] Although some reference numerals are not described, SW, SV8 and SV8 represent solenoid valves, CV2 and CV3 represent check valves, AF represents an air filter, FD represents a filter drier, and SG is a level meter.

[34] The outdoor unit 20 includes a liquid separator ACC, which separates refrigerant liquid from refrigerant gas, which is lowered in pressure while passing through the evaporator 11 of the indoor unit 10 during a cooling operation, and separates liquid from refrigerant gas, which is super-heated by a super cooling and super heating unit SRH during the heating operation, compressors COMl and COM2, which compress the refrigerant gas introduced from the liquid separator ACC such that refrigerant gas has a high temperature and pressure, a condenser and evaporator 21, which condenses the refrigerant gas introduced from the compressors COMl and COM2 to make a high temperature and pressure liquid refrigerant during the cooling operation and evaporates the refrigerant, which has a temperature lower than a temperature of an external air, through the heat-exchange between the refrigerant and the air during the heating operation, a propeller fan 22, which allows the air to flow into the condenser and evaporator 21, the super cooling and super heating unit SRH, which performs a super cooling operation and a super heating operation relative to the high pressure liquid refrigerant introduced from the indoor unit 10 and the low temperature and pressure refrigerant gas introduced from the condenser and evaporator 21 during a heating operation, and an expansion valve EX3, which expands the refrigerant, which is supercooled by the super cooling and super heating unit SRH, such that the refrigerant has a temperature lower than a temperature of the external air, and sends the refrigerant to the condenser and evaporator 21.

[35] Although some reference numerals are not described, OSl and OS2 are oil separators for separating oil, SVl, SV2, SV3, SV4, SV5, SV9 and SV 12 are solenoid valves, and CVl, CV4, CV5 and CV6 are check valves.

[36] The refrigerant supply tube 31 and the refrigerant return tube 32 are used to connect

the indoor unit 10 and the outdoor unit 20 to each other.

[37] In the thermo-hygrostat according to the present invention, during the cooling operation, the refrigerant gas passes through evaporator 11 of the indoor unit 10, so that the air is cooled. In this case, the refrigerant gas emits evaporation heat and compression heat, which have been absorbed in the process of cooling the air, and is condensed in the condenser and evaporator 21 of the outdoor unit 20. Then, the refrigerant gas is again sent to the evaporator 11 of the indoor unit 10. Such processes described above are sequentially repeated, thereby performing the cooling function.

[38] In addition, during a cooling-dehumidifying operation, the reheating condenser 12 performs the dehumidifying function and the temperature compensating function by using the heat of an internal energy contained in the condensed high temperature and pressure liquid refrigerant, which is introduced from the condenser and evaporator 21 of the outdoor unit 20.

[39] Accordingly, the thermo-hygrostat according to the present invention does not need to use additional electric energy for the dehumidifying function, so that energy is saved. In addition, the thermo-hygrostat maintains a super cooling cycle through a heat emission of the liquid refrigerant, so that the cooling performance is enhanced as well as the condensing performance during the summer season.

[40] In the heating operation during the winter season, the function of the condenser and evaporator 21 is converted from the condensing function into the evaporating function through a heat pump scheme, thereby absorbing a heat source from low temperature air and providing the heat source into the reheating condenser 12 of the indoor unit 10. Accordingly, the thermo-hygrostat maintains the heating function for heating the indoor air.

[41] In performing the humidifying function together with the heating function during the winter season, the refrigerant gas is introduced to both the humidifier 13 and the reheating condenser 12, so that the indoor humidity and the indoor temperature are constantly maintained by using the humidifying function.

[42] Hereinafter, an operation of thermo-hygrostat employing the heat pump according to the present invention will be described.

[43] First, a cooling operation of the thermo-hygrostat employing the heat pump will be described with reference to FIG. 2. FIG. 2 is a view representing a refrigerant cycle of the air cooled thermo-hygrostat employing the heat pump according to the present invention during the cooling operation. The cooling operation of the air cooled thermo- hygrostat employing the heat pump is performed according to cooling load calories of the indoor room in the season between the summer and the winter.

[44] First, the refrigerant gas is compressed into a high-temperature high-pressure hot gas by the compressors COMl and COM2 of the outdoor unit 20. Then, freezing oil is

separated from refrigerant gas by oil separators OSl and OS2. The freezing oil is collected to be sent to the compressors COMl and COM2, and the refrigerant gas is provided into the condenser and evaporator 21, which serves as the condenser when the solenoid valves SVl and SV2 are closed and the solenoid valves SV3 and SV4 are opened.

[45] In the condenser and evaporator 21, the refrigerant gas emits the condensing heat into the air by means of a propeller fan 22 and then is condensed into a high temperature and pressure liquid refrigerant. After that, the refrigerant gas is introduced into the indoor unit 10 by passing through the check valve CVl of the refrigerant supply tube 31.

[46] The refrigerant sequentially passes through the receiver 16 storing a pure refrigerant liquid therein, the filter drier FD and the level meter SG when the solenoid valve SV6 is opened and the check valve CV2 is closed. After that, the refrigerant is introduced into the expansion valves EXl and EX 2 when the solenoid valve SW is closed and the solenoid valve SV8 is opened, and is adiabatically expanded into a low temperature and pressure refrigerant in the expansion valves EXl and EX 2, so that the refrigerant gas having extremely low temperature is introduced into the evaporator 11.

[47] The air circulated by the blower 17 of the indoor unit 10 passes through the evaporator 11. In this process, the air is cooled by exchanging the heat with the refrigerant in the evaporator 11, and the refrigerant is evaporated. After that, the refrigerant flows through the refrigerant return tube 32 by passing through the check valve CV3 so that the refrigerant gas is introduced into the outdoor unit 20.

[48] In the outdoor unit 20, the refrigerant passes through the solenoid valve SV9 and a liquid separator ACC separating the pure refrigerant gas from the liquid refrigerant, and then is introduced into the compressors COMl and COM2. The above processes are repeated, thereby performing the cooling function.

[49] Different from the related art, the thermo-hygrostat according to the present invention forms a dual cycle including two solenoid valves SV8 and S V8', two expansion valves EXl and EX2 and two heat exchangers of the evaporators 11 that are disposed in parallel in the indoor unit 10, respectively, while including a single refrigerant supply tube 31 and a single refrigerant return tube 32 between the indoor unit 10 and the outdoor unit 20. In addition, the compressors COMl and COM2 and condenser and evaporator 21 are disposed in parallel in the outdoor unit 20, thereby forming a dual cycle. Accordingly, the thermo-hygrostat can be effectively operated corresponding to seasonal load variation.

[50] Hereinafter, a process, in which the dehumidifying function as well as the cooling function is performed, will be described with reference to FIG. 3. FIG. 3 is a view representing a refrigerant cycle of the air cooled thermo hygrostat employing the heat

pump according to the present invention during the cooling and dehumidifying operation.

[51] The cooling and dehumidifying function is a required during a period such as the summer season having a heat emission load and a high indoor humidity in that the cooling and dehumidifying function maintains the indoor temperature and humidity at a proper level. First, the cooling function is performed as described above, in which the heat exchange occurs between the refrigerant and the indoor air in the evaporator 11 having a low temperature, so that the water vapor in the air forms a dew condensation when the indoor air temperature reaches at a dew point, thereby generating condensed water. As a result, the indoor humidity is lowered and the condensed water is drained through a drain tube.

[52] Meanwhile, if the temperature of air discharged from the indoor unit 10 is below a proper temperature of an indoor room, a temperature compensating function together with the dehumidifying function must be performed. According to the related art, an electric heater type reheating coil performing the temperature compensating and dehumidifying functions operates to maintain the proper indoor temperature and humidity.

[53] However, according to the present invention, during the temperature compensating and dehumidifying operation, the liquid refrigerant, which has been condensed in the condenser and evaporator 21 of the outdoor unit 20, is partially provided into the reheating condenser 12, when the solenoid valve SVlO is closed and the solenoid valve SVl 1 is opened. Accordingly, the internal energy heat source obtained from the high temperature and pressure liquid refrigerant is used for the temperature compensating and dehumidifying operation to maintain the proper indoor temperature and humidity.

[54] As described above, according to the present invention, the internal energy heat source obtained from the liquid refrigerant having the high temperature and pressure is recycled through the reheating condenser 12, so that the electric device employing the electric heater is not additionally required, thereby remarkably saving the electric energy as compared with the related art.

[55] Hereinafter, a heating operation of the thermo-hygrostat employing the heat pump will be described with reference to FIG. 4. FIG. 4 is a view representing a refrigerant cycle of the air cooled thermo-hygrostat employing the heat pump according to the present invention during the heating operation. The heating operation is performed to raise the indoor temperature corresponding to the capacity of the heating calories of the indoor room when the outdoor temperature is lower than the indoor temperature during the winter season and the season between the summer and the winter.

[56] During the heating operation, the thermo-hygrostat operates in the heat pump scheme and the function of the condenser and evaporator 21, which is an air cooled heat exchanger, is changed from the condenser function for the cooling operation and

the cooling and dehumidifying operation to the evaporator function.

[57] First, during the heating operation, the refrigerant gas is compressed into a high temperature and pressure hot gas in the compressors COMl and COM2 and passes through oil separators OS 1 and OS2, which separate the oil from the refrigerant gas and return the oil to the compressors COMl and COM2 again. The refrigerant gas is introduced into the indoor unit 10 through the refrigerant return tube 32 when the solenoid valves S3 and S4 are closed and the solenoid valves Sl and S2 are opened.

[58] In the indoor unit 10, when the solenoid valves SV6 and SVlO are closed and the solenoid valve SVl 1 is opened, the refrigerant gas is provided to the reheating condenser 12 and exchanges heat with the air circulated by the blower 17, thereby heating the air. In this case, the refrigerant emits the heat and then is condensed.

[59] The capacity of the heating calories is controlled by the compressors COMl and

COM2 that alternately operate. The refrigerant is provided to the receiver 16 by passing through the check valve CV2, and passes through the filter drier FD and the level meter SG. Then, the refrigerant returns to the outdoor unit 20 through the refrigerant return tube 31 when the two solenoid valves S V8 and the check valve CV3 are closed and the solenoid valve SV7 is opened.

[60] In the outdoor unit 20, if the solenoid valve SV9 is closed, the refrigerant is provided to the super cooling and super heating unit SRH. If the solenoid valve SV 12 is opened, the refrigerant flows into the expansion valve EX3. The refrigerant gas is expanded in the expansion valve EX3 into the low temperature and pressure refrigerant gas having a temperature lower than that of the outdoor air, so that the refrigerant gas exchanges heat with the air of the sub-zero temperature in the condenser and evaporator 21 to be evaporated. After that, the refrigerant is provided to the super cooling and super heating unit SRH when the solenoid valve SV5 is opened.

[61] The refrigerant gas super heated by the super cooling and super heating unit SRH passes through the check valve CV6 and is provided to the liquid separator ACC. The liquid separator ACC separates the liquid from the refrigerant gas such that the pure refrigerant gas flows into the compressors COMl and COM2. The heating function is performed by repeating the above processes.

[62] According to the present invention, the refrigerant gas, which is evaporated in the condenser and evaporator 21 serving as the evaporator through the heat exchange with the outdoor air having the sub-zero temperature so that the refrigerant gas has the subzero temperature, is introduced into the super cooling and super heating unit SRH. The refrigerant gas having the sub-zero temperature exchanges heat with the liquid refrigerant, which is introduced from the indoor unit 10 into the super cooling and super heating unit SRH. Accordingly, the temperature of the refrigerant gas, which is introduced into the compressors COMl and COM2 rises to above-zero degree, so that

the liquid separator ACC and the compressors COMl and COM2 are prevented from freezing and liquid hammer phenomenon, thereby reducing the breakage of the compressors COMl and COM2. In addition, a super cooling cycle and a super heating cycle are simultaneously performed, so that the performance coefficient of the thermo- hygrostat is increased and the safety of the device and the efficiency of the operation are ensured.

[63] As described above, the heating operation is performed by absorbing the heat source of the sensible heat and the latent heat from the low temperature-air and providing the heat source and the ergon of the compressors COMl and COM2 to the reheating condenser 12 of the indoor unit 10 for heating the room. Accordingly, electric heater type heating device is not additionally necessary, thereby reducing the total power consumption of the thermo-hygrostat.

[64] In the actual operation of the thermo-hygrostat during the four seasons, the heating and humidifying functions require the power consumption about three times more than that of the cooling function. As a result, the thermo-hygrostat according to the present invention saves about 50% of the electric energy as compared with the electric energy used for the related art.

[65] Hereinafter, the process for simultaneously performing the heating function and the humidifying function will be described with reference to FIG. 5. FIG. 5 is a view representing a refrigerant cycle of the air cooled thermo-hygrostat employing the heat pump according to the present invention during the humidifying and heating operation.

[66] The humidifying and heating function is performed in the winter season and the season between the summer and winter seasons, in which the outdoor temperature is lower than the indoor temperature and the indoor humidity is low, to raise the indoor temperature and humidity to a proper level based on the heat capacity of an indoor room and the low indoor humidity.

[67] Similar to the heating operation described above, according to the humidifying and heating operation, the thermo-hygrostat operates in the heat pump scheme and the function of the condenser and evaporator 21 of the outdoor unit 20 is converted from the condensing function into the evaporating function.

[68] The humidifying and heating function is realized in the same way as that of the heating operation except that the refrigerant provided from the outdoor unit 20 is simultaneously introduced to the humidifier 13 and the reheating condenser 12 when the solenoid valve SV6 is closed and the solenoid valves SVlO and SVl 1 are opened in the indoor unit 10.

[69] The humidifier 13 heats the water stored in a tub to evaporate the water, thereby providing moisture into a room. The refrigerant gas is condensed in the humidifier 13 and passes through the check valve CW. This refrigerant gas is mixed with the re-

frigerant gas, which does not pass through the humidifier 13, at a front end of the reheating condenser 12 when the solenoid valve SVl 1 is opened, so that the mixed refrigerant gas is provided to the reheating condenser 12.

[70] The refrigerant gas exchanges the heat with the air circulated by the blower 17 of the indoor unit 10 to heat the indoor room. After that, the refrigerant gas is condensed again and is stored in the receiver 16 by passing through the check valve CV2. Then, the refrigerant gas flows into the outdoor unit 20 through the refrigerant return tube 32 by way of the filter drier FD and the level meter SG. During the dehumidifying and the heating operation, the indoor unit 20 operates in the same ways as the heating operation described above.

[71] In a process of controlling the humidifying and heating operation, the humidifying operation is primarily performed such that the humidity calories obtained through the evaporation of water can be used for the heating operation during the humidifying operation. Meanwhile, when the heating load is not sufficient, the reheating condenser 12 operates, such that the humidifying operation and the heating operation can be simultaneously performed. As described above, the humidifying and heating function is performed only through the outdoor air-heat source, so that the energy is remarkably saved, thereby reducing the operational cost.

[72] In addition, the thermo-hygrostat can minimize the burden of a user in terms of service fee and repairing fee, which occurs because the electrode rod heater is damaged by the scale phenomenon in the conventional electric heater type humidifier employing the electrode rod, thereby ensuring the reliability of the thermo-hygrostat.

[73] FIG. 6 is a view representing a structure of an integral type outdoor unit of the air cooled thermo-hygrostat employing the heat pump according to the present invention.

[74] The integral type outdoor unit 20 includes two compressors COMl and COM2, two condensers and evaporators 21, and two propeller fans 22, that are disposed in parallel, respectively, and are integrally formed.

[75] The outdoor unit 20 of the thermo-hygrostat according to the related art has a simple function of condensing the refrigerant gas by emitting the cooling heat source, which is obtained from the evaporator of the indoor unit 10 during the cooling operation, together with the ergon of the compressor. However, the outdoor unit 20 of the thermo-hygrostat employing the heat pump according to the present invention provides the evaporating function, in which the heat source is obtained from the air through the heat pump scheme during the winter season and provides the condensing function, in which the refrigerant gas is condensed by emitting the cooling heat source, which is obtained from the evaporator 11 of the indoor unit 10 during the cooling operation in the summer season, together with the ergon of the compressors COMl and COM2.

[76] The internal structure and the operation of the integral type outdoor unit have been described above, so the details thereof will be omitted in order to avoid redundancy. The integral type outdoor unit is manufactured as a single machine, so that the installation space thereof can be minimized and the manufacturing cost can be reduced.

[77] FIG. 7 is a view representing a structure of a separation type outdoor unit of the air cooled thermo-hygrostat employing the heat pump according to the present invention.

[78] The separation type outdoor unit 20 includes two compressors COMl and COM2, two condensers and evaporators 21, and two propeller fans 22 that are disposed in parallel, respectively. These components can be prepared as two sets.

[79] The separation type outdoor unit 20 has the same operational functions and components as those of the integral type outdoor unit described above.

[80] The separation type outdoor unit is suitable for the field where the installation space is sufficient but it is not easy to carry equipment. Since the structure of the separation type outdoor unit can be downsized by a half of the integral outdoor units, the separation type outdoor unit is suitable for the field having a small entrance.

[81] Hereinafter, a water cooled thermo-hygrostat employing the heat pump according to another embodiment of the present invention will be described with reference to FIG. 8.

[82] An indoor unit 10'of a water cooled thermo-hygrostat employing a heat pump includes expansion valves EXl and EX 2 which adiabatically expand a high temperature and pressure liquid refrigerant into a low temperature and pressure refrigerant, an evaporator 11 for evaporating the refrigerant that has passed through the expansion valves EXl and EX2 through a heat-exchange between the refrigerant and air, a reheating condenser 12, which allows the high temperature and pressure liquid refrigerant to selectively flow therethrough so as to heat and dehumidify the air, which has been cooled by exchanging the heat with the refrigerant while passing through the evaporator 11, and controls the temperature of the air through the heat exchange between the high temperature and pressure liquid refrigerant and the air, a humidifier 13, which stores a water therein and allows the high temperature and pressure liquid refrigerant to selectively flow therethrough such that the stored water is evaporated by the high temperature and pressure liquid refrigerant, a receiver 16 which sends the liquid refrigerant into the expansion valves EXl and EX2, a blower 17, which circulates the air through the evaporator 11, the reheating condenser 12 and the humidifier 13 such that the air is fed into an indoor room, solenoid valves SV6, SVlO and SVl 1 and a check valve CV7 that allow the high temperature and pressure refrigerant to flow only into the reheating condenser 12 or to flow into the reheating condenser 12 and the humidifier 13 during a heating operation, a liquid separator ACC, which separates refrigerant liquid from refrigerant gas, which is lowered in pressure

while passing through the evaporator 11 of the indoor unit 10 during a cooling operation and separates refrigerant liquid from refrigerant gas which is super-heated by a super cooling and super heating unit SRH during the heating operation, compressors COMl and COM2, which compress the refrigerant gas introduced from the liquid separator ACC such that the refrigerant gas has a high temperature and pressure, a water cooled heat exchanger 40, which condenses the refrigerant gas introduced from the compressors COMl and COM2 to make a high temperature and pressure liquid refrigerant during the cooling operation and evaporates the refrigerant, which has a temperature lower than a temperature of an external air through the heat exchange with a cooling water during the heating operation, the super cooling and super heating unit SRH, which performs a super cooling operation and a super heating operation relative to the high pressure liquid refrigerant introduced from the indoor unit and the low temperature and pressure refrigerant gas introduced from the water cooled heat exchanger 40 during a heating operation, and an expansion valve EX3, which expands the refrigerant, which is super-cooled by the super cooling and super heating unit SRH such that the refrigerant has a temperature lower than a temperature of an external air, and then sends the refrigerant to the water cooled heat exchanger 40.

[83] An outdoor unit 20'of the water cooled thermo-hygrostat employing the heat pump includes a cooling water coil 21'which cools the cooling water and a propeller fan 22 which allows the air to flow into the cooling water coil 21'.

[84] In addition, a cooling water tube 41 connects the water cooled heat exchanger 40 of the indoor unit 10'and the cooling water coil 21 'of the outdoor unit 20'to each other. A cooling water circulation pump 42 is installed on the cooling water pipe 41.

[85] Different from the air cooled thermo-hygrostat, the water cooled thermo-hygrostat has a compressor-freezer, which serves as an air cooled heat pump, in the indoor unit 10'and additionally has the water cooled heat exchanger 40, which serves as a condenser of emitting the condensing heat by using the cooling water of the outdoor unit 20'and serves as an evaporator of absorbing the sensible heat of the cooling water, in the indoor unit 10'.

[86] The structure and operation of non-described components are identical to those of the air cooled thermo-hygrostat, so they will be not be further described to avoid redundancy.

[87] The water cooled thermo-hygrostat employing the heat pump is applicable for a field where the thermo-hygrostat having large capacity is installed and for a field where the distance between an indoor unit and an outdoor unit is too long to employ the air cooled thermo-hygrostat.

[88] The water cooled outdoor unit 20'has a hermetical structure in which an anti- freezing solution, such as ethylene glycol, is input into the cooling water such that the

cooling water absorbs the heat source from the cold air during the winter season, so that the freezing point of the cooling water is lowered to a sub-zero temperature, thereby operating the heat pump cycle.

[89] During the summer season, the cooling water coil 21'of the water cooled outdoor unit 20'serves to emit the heat source for the cooling function and the cooling and de- humidifying function, and the air cooled heat exchanger 40 is used as the evaporator and as the condenser.