Heat cycle

Abstract

The waste heat recovering operation mode (a Rankine cycle) is started and operated for a predetermined period of time T 1 (s) (S 430 to S 450 ). In the case where the difference (P 2 −P 1 ) between the upstream pressure P 1 and the downstream pressure P 2 of the liquid pump is higher than the predetermined pressure P, the waste heat recovering operation mode is continued. In the case where the difference (P 2− P 1 ) is not more than the predetermined pressure P, after the air conditioning mode is started (S 480 to S 500 ), the waste heat recovering operation mode is started again (S 430 to S 450 ). Due to the foregoing, it is possible to provide a heat cycle, which is provided with a refrigerating cycle and a Rankine cycle which are changeable each other, in which an incomplete start at the time of Rankine cycle can be reduced and a deterioration of the cycle efficiency can be reduced.

1 . A heat cycle device comprising: 
 a rotary fluid machine for mutually converting between fluid energy of refrigerant and mechanical rotary energy;    a condenser for condensing the refrigerant supplied from the rotary fluid machine;    a Rankine cycle system including a fluid pump for moving the refrigerant supplied from the condenser and also including a vapor generator for heating the refrigerant, which has been moved by the fluid pump, by the heat of a heat generating body;    a refrigerating cycle system including an evaporator for evaporating the refrigerant supplied from the condenser; and    a control unit for conducting a refrigerant condensing operation in which the refrigerant in the refrigerating cycle system is compressed by the rotary fluid machine at the time of operating the Rankine cycle system and the compressed refrigerant is condensed by the condenser.    
   
   
       2 . A heat cycle device according to  claim 1 , the control unit including: 
 a judging means for judging whether or not the Rankine cycle system is normally operated after the operation of the Rankine cycle system was started; and    a control means for continuing the operation of the Rankine cycle system in the case where it is judged that the Rankine cycle system is normally operated, and for conducting the refrigerant condensing operation in the case where it is judged that the Rankine cycle system is not normally operated.    
   
   
       3 . A heat cycle device according to  claim 2 , further comprising: 
 an upstream refrigerant pressure sensor for measuring pressure of the refrigerant, arranged in an upstream side portion of the refrigerant flow of the fluid pump; and    a downstream refrigerant pressure sensor for measuring pressure of the refrigerant, arranged in a downstream side portion of the refrigerant flow of the fluid pump, wherein    the judging means judges that the Rankine cycle is normally operated at the time of operating the Rankine cycle system in the case where a difference (P 2 −P 1 ) between the detected pressure of the downstream refrigerant pressure sensor and the detected pressure (P) of the upstream refrigerant pressure sensor is larger than the predetermined pressure (P), and the judging means judges that the Rankine cycle is not normally operated at the time of operating the Rankine cycle system in the case where the difference (P 2 −P 1 ) between the detected pressure (P 2 ) of the downstream refrigerant pressure sensor and the detected pressure (P 1 ) of the upstream refrigerant pressure sensor is not more than the predetermined pressure (P).    
   
   
       4 . A heat cycle device according to  claim 2 , wherein the judging means judges that the Rankine cycle system is normally operated in the case where a work-load of the liquid pump is heavier than a predetermined work-load at the time of operating the Rankine cycle system, and the judging means judges that the Rankine cycle system is not normally operated in the case where the work-load of the liquid pump is not more than the predetermined work-load at the time of operating the Rankine cycle system.  
   
   
       5 . A heat cycle device according to  claim 4 , wherein the liquid pump is an electric liquid pump, and the work-load is represented by electric power consumed by the electric liquid pump.  
   
   
       6 . A heat cycle device according to one of  claim 1 , further comprising an air blowing means for blowing air, the temperature of which is adjusted by the refrigerating cycle system, wherein 
 the control unit conducts the refrigerant condensing operation under the condition that the air blowing means is not operated.    
   
   
       7 . A heat cycle device according to  claim 1 , further comprising a sensor for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump, wherein 
 the control unit determines the time, which has passed from the start of the refrigerant condensing operation to when the physical value measured by the sensor shows that the refrigerant inside the refrigerant pump is in the supercooled state, to be the continuation time for continuing the refrigerant condensing operation.    
   
   
       8 . A heat cycle device according to  claim 1 , wherein the condenser is a heat exchanger for condensing the refrigerant by exchanging heat between the outside air and the refrigerant, 
 the heat cycle device further comprising:    an outside air temperature sensor for measuring the temperature of the outside air; and    a sensor for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump, wherein    the control unit determines a target temperature at which the refrigerant inside the refrigerant pump is in the supercooled state according to the outside air temperature measured by the outside air temperature sensor, and further the control unit determines the time, which has passed from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the target temperature, to be the continuation time for continuing the refrigerant condensing operation.    
   
   
       9 . A heat cycle device according to  claim 7 , wherein the sensor is a temperature sensor for measuring the temperature of the housing of the refrigerant pump.  
   
   
       10 . A heat cycle device according to  claim 7 , wherein the sensor is a temperature sensor for measuring the temperature of air immediately after heat was exchanged with the refrigerant in the evaporator.  
   
   
       11 . A heat cycle device according to  claim 1 , wherein the condenser is a heat exchanger for condensing the refrigerant by exchanging heat between the outside air and the refrigerant, 
 further comprising an outside air temperature sensor for measuring the outside air temperature, wherein    the control unit includes a continuation time setting means for determining the continuation time (T 21 ), in which the refrigerant condensing operation is continued, according to the temperature measured by the outside air temperature sensor.    
   
   
       12 . A heat cycle device according to  claim 1 , wherein the rotary fluid machine is a reversible rotary machine capable of being reversibly operated as an expansion machine for obtaining power when the refrigerant is expanded, or operated as a compressor for compressing the refrigerant when power is supplied to the compressor.  
   
   
       13 . A heat cycle device according to  claim 12 , wherein the control unit conducts the refrigerant condensing operation by operating the rotary fluid machine as a compressor before the rotary fluid machine is operated as an expansion machine and the operation of the Rankine cycle system is started.  
   
   
       14 . A heat cycle device according to  claim 12 , wherein the reversible rotary machine is composed being integrated with the fluid pump into one body, and 
 the fluid pump is arranged so that it can be cooled by the gas-phase refrigerant sucked into the reversible rotary machine at the time of operating the refrigerating cycle system.    
   
   
       15 . A heat cycle device according to  claim 1 , wherein the rotary fluid machine includes an expansion machine for expanding the refrigerant to obtain power and a compressor for compressing the refrigerant when power is supplied to the compressor.  
   
   
       16 . A heat cycle device according to  claim 15 , wherein the control unit conducts the refrigerant condensing operation by operating the compressor before the expansion machine is operated and the operation of the Rankine cycle system is started.  
   
   
       17 . A heat cycle device according to  claim 15 , wherein the control unit conducts the refrigerant condensing operation by operating the compressor simultaneously when the expansion machine is operated and the operation of the Rankine cycle system is started.  
   
   
       18 . A heat cycle device comprising: 
 a Rankine cycle system including a fluid pump for moving refrigerant and also including a vapor generator for heating the refrigerant, which has been moved by the fluid pump, by the heat of a heat generating body;    a refrigerating cycle system including an evaporator for evaporating the refrigerant; and    a control unit for conducting the cooling operation for cooling the fluid pump by operating the refrigerating cycle system at the time of operating the Rankine cycle system.    
   
   
       19 . A heat cycle device according to  claim 18 , wherein the refrigerating cycle system includes a compressor, and the fluid pump is arranged so that it can be cooled by the gas-phase refrigerant sucked into the compressor.  
   
   
       20 . A heat cycle device according to  claim 18 , wherein the control unit conducts the cooling operation before the operation of the Rankine cycle system is started and/or while the Rankine cycle system is being operated.  
   
   
       21 . A heat cycle comprising: 
 a refrigerating cycle in which refrigerant of low pressure is evaporated so as to absorb heat from a low temperature side and the evaporated gas-phase refrigerant is compressed so as to raise the temperature and the heat absorbed from the low temperature side is radiated to a high temperature side so as to condense the gas-phase refrigerant into the liquid-phase refrigerant;    a Rankine cycle including a vapor generator for generating the gas-phase refrigerant by heating the liquid-phase refrigerant of the refrigerating cycle by the waste heat of a heat generating body, also including a liquid-phase pipe for connecting a liquid-phase takeout section for taking out the liquid-phase refrigerant from the refrigerating cycle, with the vapor generator, also including a liquid pump arranged in the liquid-phase pipe, for moving the liquid phase refrigerant to the vapor generator, also including an expansion machine for obtaining power by expanding the gas-phase refrigerant, and also including a condenser for condensing the gas-phase refrigerant which has been expanded by the expansion machine;    a control means for controlling a state of operation of the refrigerating cycle and also controlling a state of operation of Rankine cycle; and    a change-over means for changing over between a case in which the Rankine cycle is operated and a case in which the refrigerating cycle is operated by a signal sent from the control means, wherein    the control means operates the Rankine cycle in such a manner that the refrigerating cycle is operated by the refrigerant condensing operation so as to condense the gas-phase refrigerant into the liquid-phase refrigerant and then the Rankine cycle is operated.    
   
   
       22 . A heat cycle comprising: 
 a refrigerating cycle in which refrigerant of low pressure is evaporated so as to absorb heat from a low temperature side and the evaporated gas-phase refrigerant is compressed so as to raise the temperature and the heat absorbed from the low temperature side is radiated to a high temperature side so as to condense the gas-phase refrigerant into the liquid-phase refrigerant;    a Rankine cycle including a vapor generator for generating the gas-phase refrigerant by heating the liquid-phase refrigerant of the refrigerating cycle by the waste heat of a heat generating body, also including a liquid-phase pipe for connecting a liquid-phase takeout section for moving the liquid-phase refrigerant from the refrigerating cycle, with the vapor generator, also including a liquid pump arranged in the liquid-phase pipe, for moving the liquid-phase refrigerant to the vapor generator, also including an expansion machine for obtaining power by expanding the gas-phase refrigerant, and also including a condenser for condensing the gas-phase refrigerant which has been expanded by the expansion machine;    a control means for controlling a state of operation of the refrigerating cycle and also controlling a state of operation of Rankine cycle; and    a change-over means for changing over between the case in which the Rankine cycle is operated and the case in which the refrigerating cycle is operated by a signal sent from the control means, wherein    after the Rankine cycle has been operated, the control means judges whether or not the Rankine cycle is normally operated,    in the case where operation of the Rankine cycle has been judged to be normal, the Rankine cycle is kept operated and    in the case where operation of the Rankine cycle has been judge to be not normal, the control means operates in such a manner that it stops the operation of the Rankine cycle and operates the refrigerating cycle so as to conduct the refrigerant condensing operation for recovering the liquid-phase refrigerant and the Rankine cycle is operated again after the refrigerant condensing operation.    
   
   
       23 . A heat cycle according to  claim 22 , further comprising: 
 an upstream refrigerant pressure sensor arranged in a portion on the upstream side of the flow of the refrigerant of the liquid pump, the upstream refrigerant pressure sensor outputting a signal of the refrigerant pressure to the control means; and    a downstream refrigerant pressure sensor arranged in a portion on the downstream side of the flow of the refrigerant of the liquid pump, the downstream refrigerant pressure sensor outputting a signal of the refrigerant pressure to the control means, wherein    in the case where a value (P 2 −P 1 ), which is obtained when a detected pressure value (P 1 ) of the upstream refrigerant pressure sensor is subtracted from a detected pressure value (P 2 ) of the downstream refrigerant pressure sensor, is higher than a predetermined pressure value (P) when the Rankine cycle is operated, the control means judges that the Rankine cycle is normally operated, and in the case where the value (P 2 −P 1 ), which is obtained when the detected pressure value (P 1 ) of the upstream refrigerant pressure sensor is subtracted from the detected pressure value of the downstream refrigerant pressure sensor, is not more than the predetermined pressure value (P), the control means judges that the Rankine cycle is not normally operated.    
   
   
       24 . A heat cycle according to  claim 22 , wherein the control means judges that the Rankine cycle is normally operated in the case where a work-load of the liquid pump is more than a predetermined work-load when the Rankine cycle is operated, and 
 the control means judges that the Rankine cycle is not normally operated in the case where the work-load of the liquid pump is not more than the predetermined work-load when the Rankine cycle is operated.    
   
   
       25 . A heat cycle according to  claim 24 , wherein the liquid pump is an electric liquid pump driven by electricity, and 
 the work-load is represented by electric power consumed by the electrically-driven liquid pump.    
   
   
       26 . A heat cycle according to  claim 21 , wherein the expansion machine is a reversible rotary machine having the function of a compressor for compressing the gas-phase refrigerant in the refrigerating cycle, 
 the reversible rotary machine is integrated with the liquid pump, and    the liquid pump is cooled by the gas-phase refrigerant sucked into the reversible rotary machine at the time of operating the refrigerating cycle.    
   
   
       27 . A heat cycle according to  claim 21 , further comprising: 
 an air blowing means for blowing air conditioned by the refrigerating cycle; and    an operation demand means for demanding the operation of the refrigerating cycle, wherein    in the case of conducting the refrigerant condensing operation, the control means conducts the refrigerant condensing operation without operating the air blowing means when the operation of the refrigerating cycle is not demanded by the operation demand means.    
   
   
       28 . A heat cycle according to  claim 21 , wherein, 
 the condenser is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant,    the heat cycle further comprises an outside air temperature sensor for measuring the temperature of the outside air,    the control means determines the continuation time (T 21 ) for continuing the refrigerant condensing operation, and    the continuation time (T 21 ) is determined on the basis of the outside air temperature.    
   
   
       29 . A heat cycle according to  claim 21 , further comprising a sensor for measuring a physical value having a correlation with a temperature of the refrigerant inside the liquid pump, wherein 
 the control means determines the continuation time in which the refrigerant condensing operation is continued, and    the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the temperature at which the refrigerant inside the refrigerant pump is supercooled.    
   
   
       30 . A heat cycle according to  claim 21 , wherein 
 the condenser is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant,    the heat cycle further comprises an outside air temperature sensor for measuring the temperature of the outside air and also comprises a sensor for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump,    the control means determines the temperature at which the refrigerant inside the refrigerant pump is supercooled by the outside air temperature, and also determines the continuation time in which the refrigerant condensing operation is continued, and 
 the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the temperature at which the refrigerant inside the refrigerant pump is supercooled.  
   
   
   
       31 . A heat cycle according to  claim 30 , wherein the sensor for measuring the physical value is a temperature sensor for measuring the temperature of the housing of the refrigerant pump  
   
   
       32 . A heat cycle according to  claim 30 , wherein the refrigerating cycle includes an evaporator for evaporating the refrigerant of low pressure by exchanging heat between the refrigerant of low pressure and air, and 
 the sensor for measuring the physical value is a temperature sensor for measuring the temperature of air immediately after heat is exchanged with the refrigerant of low pressure.    
   
   
       33 . A heat cycle device according to  claim 8 , wherein the sensor is a temperature sensor for measuring the temperature of the housing of the refrigerant pump.  
   
   
       34 . A heat cycle device according to  claim 8 , wherein the sensor is a temperature sensor for measuring the temperature of air immediately after heat was exchanged with the refrigerant in the evaporator.  
   
   
       35 . A heat cycle according to  claim 22 , wherein the expansion machine is a reversible rotary machine having the function of a compressor for compressing the gas-phase refrigerant in the refrigerating cycle, 
 the reversible rotary machine is integrated with the liquid pump, and    the liquid pump is cooled by the gas-phase refrigerant sucked into the reversible rotary machine at the time of operating the refrigerating cycle.    
   
   
       36 . A heat cycle according to  claim 22 , further comprising: 
 an air blowing means for blowing air conditioned by the refrigerating cycle; and    an operation demand means for demanding the operation of the refrigerating cycle, wherein    in the case of conducting the refrigerant condensing operation, the control means conducts the refrigerant condensing operation without operating the air blowing means when the operation of the refrigerating cycle is not demanded by the operation demand means.    
   
   
       37 . A heat cycle according to  claim 22 , wherein, 
 the condenser is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant,    the heat cycle further comprises an outside air temperature sensor for measuring the temperature of the outside air,    the control means determines the continuation time (T 21 ) for continuing the refrigerant condensing operation, and    the continuation time (T 21 ) is determined on the basis of the outside air temperature.    
   
   
       38 . A heat cycle according to  claim 22 , further comprising a sensor for measuring a physical value having a correlation with a temperature of the refrigerant inside the liquid pump, wherein 
 the control means determines the continuation time in which the refrigerant condensing operation is continued, and    the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the temperature at which the refrigerant inside the refrigerant pump is supercooled.    
   
   
       39 . A heat cycle according to  claim 22 , wherein 
 the condenser is a heat exchanger for condensing the gas-phase refrigerant by exchanging heat between the outside air and the refrigerant,    the heat cycle further comprises an outside air temperature sensor for measuring the temperature of the outside air and also comprises a sensor for measuring a physical value having a correlation with the temperature of the refrigerant inside the liquid pump,    the control means determines the temperature at which the refrigerant inside the refrigerant pump is supercooled by the outside air temperature, and also determines the continuation time in which the refrigerant condensing operation is continued, and 
 the continuation time is the time from the start of the refrigerant condensing operation to when the physical value measured by the sensor becomes the temperature at which the refrigerant inside the refrigerant pump is supercooled.  
   
   
   
       40 . A heat cycle according to  claim 29 , wherein the sensor for measuring the physical value is a temperature sensor for measuring the temperature of the housing of the refrigerant pump  
   
   
       41 . A heat cycle according to  claim 29 , wherein the refrigerating cycle includes an evaporator for evaporating the refrigerant of low pressure by exchanging heat between the refrigerant of low pressure and air, and 
 the sensor for measuring the physical value is a temperature sensor for measuring the temperature of air immediately after heat is exchanged with the refrigerant of low pressure.