Space and water heating apparatus

Abstract

To reduce remaining air bubbles, a space and water heating apparatus includes external and internal circulation channels, including a shared portion, to respectively circulate a heating medium through space heating equipment and a water-heating heat exchanger, a discharger that discharges air bubbles, and a circulation switcher (three-way valve) that switches among a space heating operation mode, a water heating operation mode, and a simultaneous operation mode to respectively circulate the heating medium along the external circulation channel, the internal circulation channel, and both the external and internal circulation channels. Feeding the heating medium is followed by a test operation including external- and internal-channel discharge processes to respectively discharge air bubbles from the external and internal circulation channels by circulating the heating medium. In the internal-channel discharge process, the water heating or simultaneous operation mode is switched to the space heating operation mode during operation of a circulation pump.

1 . A space and water heating apparatus for performing a space heating operation and a water heating operation, the space heating operation being an operation in which a heating medium is circulated by a circulation pump through space heating equipment for space heating, the water heating operation being an operation in which the heating medium circulated in the space heating operation is circulated through a water-heating heat exchanger to heat, by heat exchange with the heating medium, water supplied to the water-heating heat exchanger, the apparatus comprising: 
 an external circulation channel to circulate the heating medium through the space heating equipment;   an internal circulation channel to circulate the heating medium through the water-heating heat exchanger, the internal circulation channel including a shared portion shared with the external circulation channel;   a heater configured to heat the heating medium in the shared portion;   a temperature sensor configured to detect a temperature of the heating medium in the shared portion;   a circulation switcher configured to switch among a space heating operation mode in which the heating medium is circulated along the external circulation channel, a water heating operation mode in which the heating medium is circulated along the internal circulation channel, and a simultaneous operation mode in which the heating medium is circulated along the external circulation channel and the internal circulation channel;   a discharger configured to discharge air bubbles contained in the heating medium; and   a test operation controller configured to control a test operation to be performed after the heating medium is fed, the test operation being an operation in which the heating medium is circulated to facilitate discharge of the air bubbles,   wherein the test operation includes an external-channel discharge process to facilitate discharge of the air bubbles from the external circulation channel and an internal-channel discharge process to facilitate discharge of the air bubbles from the internal circulation channel, and   in the internal-channel discharge process, the circulation switcher switches from the water heating operation mode or the simultaneous operation mode to the space heating operation mode during operation of the circulation pump.   
     
     
         2 . The space and water heating apparatus according to  claim 1 , wherein 
       in the internal-channel discharge process, the circulation switcher switches from the water heating operation mode to the space heating operation mode during operation of the circulation pump. 
     
     
         3 . The space and water heating apparatus according to  claim 1 , wherein 
       in the external-channel discharge process, the circulation pump is operated while the circulation switcher maintains the space heating operation mode, and 
       the test operation controller performs the internal-channel discharge process after performing the external-channel discharge process. 
     
     
         4 . The space and water heating apparatus according to  claim 1 , wherein 
       the test operation controller performs a plurality of the internal-channel discharge processes in each of which the circulation switcher switches to the space heating operation mode at a different timing or the circulation pump circulates the heating medium at a different flow velocity. 
     
     
         5 . The space and water heating apparatus according to  claim 1 , wherein 
       the test operation includes a heating-discharge process in which the heating medium heated by the heater is circulated along at least one of the external circulation channel or the internal circulation channel, and 
       the test operation controller performs the heating-discharge process after performing the external-channel discharge process and the internal-channel discharge process. 
     
     
         6 . The space and water heating apparatus according to  claim 5 , wherein 
       in the heating-discharge process, the heater heats the heating medium until the temperature detected by the temperature sensor reaches a predetermined temperature, and 
       the predetermined temperature is set to a higher temperature of a target temperature of the heating medium in the space heating operation or a target temperature of the heating medium in the water heating operation. 
     
     
         7 . The space and water heating apparatus according to  claim 2 , wherein 
       in the external-channel discharge process, the circulation pump is operated while the circulation switcher maintains the space heating operation mode, and 
       the test operation controller performs the internal-channel discharge process after performing the external-channel discharge process. 
     
     
         8 . The space and water heating apparatus according to  claim 2 , wherein 
       the test operation controller performs a plurality of the internal-channel discharge processes in each of which the circulation switcher switches to the space heating operation mode at a different timing or the circulation pump circulates the heating medium at a different flow velocity. 
     
     
         9 . The space and water heating apparatus according to  claim 2 , wherein 
       the test operation includes a heating-discharge process in which the heating medium heated by the heater is circulated along at least one of the external circulation channel or the internal circulation channel, and 
       the test operation controller performs the heating-discharge process after performing the external-channel discharge process and the internal-channel discharge process.  
     
     
         10 . The space and water heating apparatus according to  claim 9 , wherein 
       in the heating-discharge process, the heater heats the heating medium until the temperature detected by the temperature sensor reaches a predetermined temperature, and 
       the predetermined temperature is set to a higher temperature of a target temperature of the heating medium in the space heating operation or a target temperature of the heating medium in the water heating operation.