Heat pump system with the function of dehumidification unit inside indoor unit and its controlling method

Abstract

Provided is a cooling/heating heat pump system, including a cooling line in which a high-temperature and high-pressure refrigerant passes through a 4-way valve and changes into a low-temperature and low-pressure refrigerant, flows into the 4-way valve through an indoor heat exchanger seated in an interior unit, and circulates back to an intake side of the compressor; and a dehumidification line that is formed between the discharge side and the 4-way valve and in which the refrigerant discharged from the compressor is discharged to the dehumidification line, a high-temperature and high-pressure refrigerant coming through an upper refrigerant line of a dehumidification heat exchanger changes into a low-temperature and low-pressure refrigerant while passing through a second expansion valve, and flows back into a lower refrigerant line of the dehumidification heat exchanger, and the passing refrigerant circulates to the compressor through the intake side of the compressor.

What is claimed is: 
     
         1 . A cooling/heating heat pump system with a function of a dehumidification unit ( 200 ) inside an indoor unit, comprising:
 a cooling line ( 100 ) in which a high-temperature and high-pressure refrigerant discharged from a discharge side ( 11 ) of a compressor ( 10 ) passes through a 4-way valve ( 20 ) and changes into a low-temperature and low-pressure refrigerant while passing through a first expansion valve ( 40 ) after passing through an outdoor unit ( 30 ), flows into the 4-way valve ( 20 ) through an indoor heat exchanger ( 51 ) seated in an interior unit ( 50 ), and circulates back to an intake side ( 12 ) of the compressor ( 10 ); and   a dehumidification line ( 200 ) that is formed between the discharge side ( 11 ) and the 4-way valve ( 20 ) and in which the high-temperature and high-pressure refrigerant discharged from the discharge side ( 11 ) of the compressor ( 10 ) is discharged to the dehumidification line ( 200 ), a high-temperature and high-pressure refrigerant coming through an upper refrigerant line ( 210   a ) of a dehumidification heat exchanger ( 210 ) spaced apart from and seated parallel with a lower end of the indoor heat exchanger ( 51 ) of the interior unit ( 50 ) changes into a low-temperature and low-pressure refrigerant while passing through a second expansion valve ( 220 ), and flows back into a lower refrigerant line of the dehumidification heat exchanger ( 210 ), and the passing refrigerant circulates to the compressor ( 10 ) through the intake side ( 12 ) of the compressor ( 10 ),   wherein indoor air flowing inside through a front surface of the interior unit ( 50 ) is cooled and dehumidified while passing through a heat exchanger of the lower refrigerant line ( 210   b ) of the dehumidification heat exchanger ( 210 ), and the cooled and dehumidified air increases in temperature while passing through a heat exchanger of the upper refrigerant line ( 210   a ) and is then cooled and dehumidified while passing through the indoor heat exchanger ( 51 ) and supplied to an interior;   when a cooling mode is started by a controller ( 400 ), a dehumidification valve ( 230 ) formed on the dehumidification line ( 200 ) of the discharge side ( 11 ) of the compressor ( 10 ) is closed and simultaneously a cooling/heating valve ( 60 ) is opened;   when a dehumidification mode is started, the dehumidification valve ( 230 ) formed on the dehumidification line ( 200 ) of the discharge side ( 11 ) of the compressor ( 10 ) is opened and simultaneously the cooling/heating valve ( 60 ) is closed,   when a cooling/dehumidification mode is started, the dehumidification valve ( 230 ) formed on the dehumidification line ( 200 ) of the discharge side ( 11 ) of the compressor ( 10 ) is opened and simultaneously the cooling/heating valve ( 60 ) is opened; and   a refrigerant discharged from the compressor ( 10 ) is distributed and supplied at a preset ratio to the cooling line ( 100 ) and the dehumidification line ( 200 ), and flows inside from a liquid separator ( 80 ) mounted at a front end of the compressor ( 10 ) to circulate to the compressor ( 10 );   there is added a heating line ( 300 ) that includes the dehumidification line ( 200 ) and in which a high-temperature and high-pressure refrigerant discharged from a discharge side ( 11 ) of a compressor ( 10 ) passes through a 4-way valve ( 20 ) and changes into a low-temperature and low-pressure refrigerant while passing through a first expansion valve ( 40 ) after passing through an indoor heat exchanger ( 51 ) seated in an interior unit ( 50 ), and circulates back to an intake side ( 12 ) of the compressor ( 10 ) through an outdoor unit ( 30 ) and the 4-way valve ( 20 ),   several reheat pipes ( 70 ) having an electric heater rod ( 71 ) are formed at an inflow side of the outdoor unit ( 30 ) of the heating line ( 300 ), surface temperature of the outdoor heat exchanger ( 31 ) of the outdoor unit ( 30 ) and humidity temperature of inflow air flowing into the outdoor unit ( 30 ) are measured, the controller ( 400 ) determines whether to perform defrosting, and when a defrosting condition is reached, the electric heater rods ( 70 ) are operated such that several pieces are selectively simultaneously operated;   when a heating mode is started by a controller ( 400 ), a dehumidification valve ( 230 ) formed on the dehumidification line ( 200 ) of the discharge side ( 11 ) of the compressor ( 10 ) is closed and simultaneously a cooling/heating valve ( 60 ) is opened;   when a dehumidification mode is started, the dehumidification valve ( 230 ) formed on the dehumidification line ( 200 ) of the discharge side ( 11 ) of the compressor ( 10 ) is opened and simultaneously the cooling/heating valve ( 60 ) is closed,   when a heating/dehumidification mode is started, the dehumidification valve ( 230 ) formed on the dehumidification line ( 200 ) of the discharge side ( 11 ) of the compressor ( 10 ) is opened and simultaneously the cooling/heating valve ( 60 ) is also opened, and   a refrigerant discharged from the compressor ( 10 ) is distributed and supplied at a preset ratio to the heating line ( 300 ) and the dehumidification line ( 200 ) and flows inside from a liquid separator ( 80 ) mounted at a front end of the compressor ( 10 ) to circulate to the compressor ( 10 );   several refrigerant divergent paths of the outdoor heat exchanger ( 35 ) of the outdoor unit ( 30 ) are composed of an upper path part ( 35   a ), a middle path part ( 35   b ), and a lower path part ( 35   c ),   in the upper path part ( 35   a ), a refrigerant flows into the upper end of the upper path part, forms a preset refrigerant path channel, is discharged to the upper end, and flows into an outdoor refrigerant collector ( 38 ) positioned at outer lower end of the outdoor heat exchanger;   in the middle path part ( 35   b ), a refrigerant flows into the middle portion of the middle path part, forms a preset refrigerant path channel, is discharged to the middle portion, and flows into the outdoor refrigerant collector ( 38 );   in the lower path part ( 35   c ), a refrigerant flows into the lower end of the middle path part, forms a preset refrigerant path channel, is discharged to the lower end, and flows into the outdoor refrigerant collector ( 38 ); and   a refrigerant mixed in the outdoor refrigerant collector ( 38 ) flows back into the outdoor heat exchanger ( 35 ), exchanges heat, and is then discharged back to the outdoor heat exchanger ( 35 ).   
     
     
         2 . The heat pump system of  claim 1 , wherein the number of refrigerant pipes forming the upper refrigerant line ( 210   a ) functioning as the condenser of the dehumidification heat exchanger ( 210 ) is greater than the number of refrigerant pipes forming the lower refrigerant lines ( 210   b ) functioning as the evaporator. 
     
     
         3 . The cooling/heating heat pump system of  claim 1 , wherein the dehumidification heat exchanger ( 210 ) has thermal capacity smaller than that of the indoor heat exchanger ( 51 ). 
     
     
         4 . The cooling/heating heat pump system of  claim 2 , wherein the dehumidification heat exchanger ( 210 ) has thermal capacity smaller than that of the indoor heat exchanger ( 51 ). 
     
     
         5 . A method of controlling a cooling/heating heat pump with a function of a dehumidification unit inside an interior unit ( 50 ), wherein
 an indoor heat exchanger and a dehumidification heat exchanger ( 210 ) spaced apart from the indoor heat exchanger ( 51 ) and correspondingly mounted at the lower end is separately mounted on an interior unit ( 50 ),   a controller ( 400 ) is formed for the cooling/heating heat pump composed of:   a cooling line ( 100 ) and a heating line ( 300 ) connected to an outdoor heat exchanger ( 31 ) of an outdoor unit ( 30 ) and formed by connecting the indoor heat exchanger ( 51 ) and the outdoor heat exchanger ( 31 ); and   a dehumidification line ( 200 ) by an upper refrigerant line ( 210   a ) functioning as a condenser in the dehumidification heat exchanger ( 210 ) and a lower refrigerant line ( 210   b ) functioning as an evaporator separately from the cooling line ( 100 ) and the heating line ( 300 ),   the dehumidification line ( 200 ) is formed between the discharge side ( 11 ) and the 4-way valve ( 20 ) and in which the high-temperature and high-pressure refrigerant discharged from the discharge side ( 11 ) of the compressor ( 10 ) is discharged to the dehumidification line ( 200 ), a high-temperature and high-pressure refrigerant coming through an upper refrigerant line ( 210   a ) of a dehumidification heat exchanger ( 210 ) spaced apart from and seated parallel with a lower end of the indoor heat exchanger ( 51 ) of the interior unit ( 50 ) changes into a low-temperature and low-pressure refrigerant while passing through a second expansion valve ( 220 ), and flows back into a lower refrigerant line ( 210   b ) of the dehumidification heat exchanger ( 210 ), and the passing refrigerant circulates to the compressor ( 10 ) through the intake side ( 12 ) of the compressor ( 10 );   indoor air flowing inside through a front surface of the interior unit ( 50 ) is cooled and dehumidified while passing through a heat exchanger of the lower refrigerant line ( 210   b ) of the dehumidification heat exchanger ( 210 ), and the cooled and dehumidified air increases in temperature while passing through a heat exchanger of the upper refrigerant line ( 210   a ) and is then cooled and dehumidified while passing through the indoor heat exchanger ( 51 ) and supplied to an interior;   the controller ( 400 ) receives temperature and humidity measured in real time at an indoor supply place, surface temperature of the outdoor heat exchanger ( 31 ), and humidity flowing into the outdoor heat exchanger ( 31 ), and controls them at preset values;   a control method of the cooling line ( 100 ) in which, in a cooling operation mode, the humidification line ( 200 ) is turned off, the indoor heat exchanger ( 51 ) is changed to function as an evaporator, a refrigerant is supplied, and preset temperature and humidity are controlled;   a control method of the dehumidification line ( 200 ) in which, in a dehumidification operation mode, the cooling line ( 100 ) and the heating line ( 300 ) are turned off, a refrigerant is supplied to the dehumidification heat exchanger ( 210 ), and temperature and humidity set in advance at the indoor supply place are controlled;   a control method of the heating line ( 300 ) in which, in a heating operation mode, the humidification line ( 200 ) is turned off, the indoor heat exchanger ( 51 ) is changed to function as a condenser, a refrigerant is supplied, and preset temperature and humidity are controlled;   the cooling line ( 100 ) and the dehumidification line ( 200 ) are controlled to simultaneously operate in cooling and dehumidification simultaneous operation mode,   the heating line ( 300 ) and the dehumidification line ( 200 ) are controlled to simultaneously operate in heating and dehumidification simultaneous operation mode,   the discharge side ( 11 ) of one compressor ( 10 ) constituting the heat pump is diverged into two refrigerant supplies, one is controlled such that a high-temperature and high-pressure refrigerant is supplied to the cooling line ( 100 ) and the heating line ( 300 ); the other is controlled such that each valve is opened/closed such that high-temperature and high-pressure refrigerant is supplied to the dehumidification line ( 200 );   the controller ( 400 ) measures the surface temperature of the outdoor heat exchanger ( 31 ) and humidity temperature of inflow air and determines whether to perform defrosting, and when a defrosting condition is reached, several reheat pipes ( 70 ) equipped with an electric heater rod ( 71 ) installed at the inflow side of the outdoor unit ( 30 ) are operated such that several pieces are selectively simultaneously operated, and   the controller ( 400 ), in the cooling and dehumidification simultaneous operation mode and the heating and dehumidification simultaneous operation mode, controls the amounts of refrigerants supplied separately from the discharge side ( 11 ) of the compressor ( 10 ) such that the real-time temperature and humidity at the indoor supply place reach preset temperature and humidity.