Refrigeration cycle apparatus and refrigeration cycle control method

Abstract

A combined air-conditioning and hot water supply system includes a refrigeration cycle mechanism, a hot water storage tank, and a controller. The refrigeration cycle mechanism has a compressor whose operating frequency can be controlled, a plate water-heat exchanger that heats water, a hot water supply pressure-reducing mechanism, and an outdoor heat exchanger. The controller includes a clock section, a computing section, a memory section, and a controlling section. The clock section measures time. The computing section calculates the actual hot water supply load. The memory section stores information related to the hot water supply load calculated by the computing section. The controlling section controls the operating frequency of the compressor based on the quantity of heat storage, the hot water supply load, and a preset hot water supply time.

1 - 10 . (canceled) 
     
     
         11 . A refrigeration cycle apparatus in which a refrigerant is circulated, comprising:
 a refrigeration cycle mechanism that has a compressor whose operating frequency can be controlled, a first radiator that supplies heat by means of the refrigerant to tank water that is water stored in a hot water storage tank, a first pressure-reducing mechanism, and a first evaporator, the refrigerant circulating in an order of the compressor, the first radiator, the first pressure-reducing mechanism, and the first evaporator; and   a controller,   wherein the controller includes,
 a memory section configured to store control period information indicating a preset control period, and be capable of storing other information, 
 a computing section configured to calculate a heat consumption on a time period basis, the heat consumption indicating a quantity of heat that has been supplied to an outside by the tank water within the time period, the time period being one of divided predetermined time period of a day, store the calculated heat consumption and a corresponding point in time into the memory section, and compute current heat storage in the tank water, and 
 a controlling section configured to control the operating frequency of the compressor, 
   wherein the computing section,
 from the heat consumptions of at least past one day stored in the memory section, calculates a maximum heat consumption that is to be the largest among other heat consumptions to be generated on a current day and a maximum consumption time that is a corresponding point in time to the maximum heat consumption, 
 at a time that precedes the maximum consumption time by the control period, computes the heat storage in the tank water, and on a basis of the heat storage and the maximum heat consumption of the current day, computes a hot water supply capacity target and the operating frequency of the compressor, the hot water supply capacity target serving as a heat rejection target value necessary for the first radiator to bring the heat storage in the tank water into the maximum heat consumption at the maximum consumption time, 
   wherein the controlling section controls the compressor at the operating frequency computed by the computing section, and   wherein the computing section updates the control period stored in the memory section on a basis of the hot water supply capacity target, and uses the updated control period for computing the operating frequency of the compressor in accordance with the maximum heat consumption on a following day.   
     
     
         12 . The refrigeration cycle apparatus of  claim 11 , further comprising:
 an outlet temperature sensor configured to detect a temperature of outflow water exiting from an outlet of the first radiator in a water flow path, the water flow path being a flow path of water that enters the first radiator from the hot water storage tank, passes through the first radiator, and returns to the hot water storage tank,   wherein the computing section,
 at the time that precedes the maximum consumption time by the control period, computes the heat storage in the tank water, and on the basis of the heat storage and the maximum heat consumption of the current day, calculates a target temperature indicating a target temperature of the outflow water, to bring the heat storage in the tank water into the maximum heat consumption at the maximum consumption time, and 
 computes the operating frequency of the compressor that brings the temperature of the outflow water detected by the outlet temperature sensor into the target temperature. 
   
     
     
         13 . The refrigeration cycle apparatus of  claim 11 ,
 wherein the memory section stores standard heat supply that indicates a standard value of heat to be supplied to the tank water per unit time, and   wherein the computing section, after elapse of the maximum consumption time of the current day, updates the control period stored in the memory section into a new control period in accordance with a proportion of the standard heat supply to the hot water supply capacity target, and stores the updated new control period into the memory section.   
     
     
         14 . The refrigeration cycle apparatus of  claim 11 , further comprising:
 a tank water sensor that detects a temperature of the tank water,   wherein the computing section calculates the current heat storage in the tank water by using the temperature of the tank water detected by the tank water sensor.   
     
     
         15 . The refrigeration cycle apparatus of  claim 11 , further comprising:
 an inlet temperature sensor that detects a temperature of inflow water entering an inlet of the first radiator in a water flow path, the water flow path being a flow path of water that enters the first radiator from the hot water storage tank, passes through the first radiator, and returns to the hot water storage tank; and   a high-pressure sensor that detects a high pressure from a discharge side of the compressor to a liquid side of the first pressure-reducing mechanism,   
       wherein the computing section computes a condensing temperature of the first radiator on a basis of the high pressure detected by the high-pressure sensor; and
 wherein the controlling section controls the operating frequency of the compressor by further using the condensing temperature calculated by the computing section and the temperature of the inflow water detected by the inlet temperature sensor. 
 
     
     
         16 . The refrigeration cycle apparatus of  claim 12 , further comprising:
 a water supply pump that causes the water to flow through the water flow path; and   an inlet temperature sensor that detects a temperature of inflow water entering an inlet of the first radiator in the water flow path,   wherein the controlling section keeps a temperature difference between the temperature of the inflow water detected by the inlet temperature sensor and the target temperature indicating the target temperature of the outflow water, at a predetermined value or more by controlling a flow rate of the inflow water entering the first radiator through control of the water supply pump, while controlling the operating frequency of the compressor.   
     
     
         17 . The refrigeration cycle apparatus of  claim 12 , further comprising:
 a heat rejection branch flow path that is a branch flow path that branches out from a discharge side of the compressor, the heat rejection branch flow path having a second radiator and a second pressure-reducing mechanism, the heat rejection flow path being connected in an order of the second radiator and the second pressure-reducing mechanism from the discharge side of the compressor and merging with a portion between the first pressure-reducing mechanism and the first radiator,   wherein upon executing a parallel heat rejection operation that causes a discharged refrigerant discharged from the compressor to enter and circulate through the first radiator and the second radiator, the controlling section controls the operating frequency of the compressor on a basis of a heating load indicating a load required for the second radiator,   wherein the computing section compares the temperature of the outflow water when the operating frequency of the compressor is being controlled on a basis of the heating load with the target temperature,   when the temperature of the outflow water is lower than the target temperature,   the controlling section changes the operating frequency of the compressor to an operating frequency that brings the temperature of the outflow water into the target temperature.   
     
     
         18 . The refrigeration cycle apparatus of  claim 12 , further comprising:
 a heat removal branch flow path that branches out from a branch part between the first pressure-reducing mechanism and the first evaporator, the heat removal branch flow path having a second pressure-reducing mechanism and a second evaporator, the heat removal branch flow path being connected in an order of the second pressure-reducing mechanism and the second evaporator from the branch part and merging with a suction side of the compressor,   wherein the controlling section, upon executing a parallel heat removal and heat rejection operation that is a parallel operation of a heat rejection operation of the first radiator and a heat removal operation of the second evaporator, the heat rejection operation causing the discharged refrigerant discharged from the compressor to be sucked into the compressor from the suction side via the first radiator, the first pressure-reducing mechanism, the branch part, and the first evaporator, the heat removal operation causing the discharged refrigerant to be sucked into the compressor from the suction side via the first radiator, the first pressure-reducing mechanism, the branch part, the second pressure-reducing mechanism, and the second evaporator, controls the operating frequency of the compressor on a basis of a cooling load indicating a load required for the second evaporator,   wherein the computing section compares the temperature of the outflow water when the operating frequency of the compressor is being controlled on a basis of the heating load with the target temperature, and   when the temperature of the outflow water is lower than the target temperature,   the controlling section changes the operating frequency of the compressor to an operating frequency that brings the temperature of the outflow water into the target temperature.   
     
     
         19 . A refrigeration cycle control method for a refrigeration cycle apparatus through which a refrigerant is circulated, the refrigeration cycle apparatus including
 a refrigeration cycle mechanism that has a compressor whose operating frequency can be controlled, a first radiator that supplies heat by means of the refrigerant to tank water that is water stored in a hot water storage tank, a first pressure-reducing mechanism, and a first evaporator, the refrigerant circulating in an order of the compressor, the first radiator, the first pressure-reducing mechanism, and the first evaporator,   a memory section configured to store control period information indicating a preset control period, and be capable of storing other information,   a computing section configured to calculate a heat consumption on a time period basis, the heat consumption indicating a quantity of heat that has been supplied to an outside by the tank water within the time period, the time period being one of divided predetermined time period of a day, store the calculated heat consumption and a corresponding point in time into the memory section, and compute current heat storage in the tank water, and   a controlling section configured to control the operating frequency of the compressor, the refrigeration cycle control method comprising:   from the heat consumptions of at least past one day stored in the memory section, calculating a maximum heat consumption that is to be the largest among other heat consumptions to be generated on a current day and a maximum consumption time that is a corresponding point in time to the maximum heat consumption, by the computing section;   at a time that precedes the maximum consumption time by the control period, computing the heat storage in the tank water, and on a basis of the heat storage and the maximum heat consumption of the current day, computes a hot water supply capacity target and the operating frequency of the compressor, the hot water supply capacity target being a hot water supply capacity target serving as a heat rejection target value necessary for the first radiator to bring the heat storage in the tank water into the maximum heat consumption at the maximum consumption time, by the computing section;   controlling the compressor at the operating frequency computed by the computing section, by the controlling section; and   updating the control period stored in the memory section on a basis of the hot water supply capacity target, and using the updated control period for computing the operating frequency of the compressor in accordance with the maximum heat consumption on the following day, by the computing section.