Solar heat collecting system, and apparatus and method of controlling the same

Abstract

In one embodiment, a solar heat collecting system includes a heat collector configured to heat a heat medium by a sunray. The system further includes a heater configured to heat a heating target fluid by the heat medium. The system further includes a heat medium pipe configured to circulate the heat medium between the heat collector and the heater. The system further includes a temperature sensor configured to measure a temperature of the heat medium flowing from the heat collector toward the heater, at a position located upstream of an initial bent portion of the heat medium pipe in a region where the heat medium pipe extends from the heat collector toward the heater. The system further includes a controller configured to control heating of the heat medium in accordance with the temperature of the heat medium measured by the temperature sensor.

1 . A solar heat collecting system comprising:
 a heat collector configured to heat a heat medium by a sunray;   a heater configured to heat a heating target fluid by the heat medium;   a heat medium pipe configured to circulate the heat medium between the heat collector and the heater;   a temperature sensor configured to measure a temperature of the heat medium flowing from the heat collector toward the heater, at a position located upstream of an initial bent portion of the heat medium pipe in a region where the heat medium pipe extends from the heat collector toward the heater; and   a controller configured to control heating of the heat medium in accordance with the temperature of the heat medium measured by the temperature sensor.   
     
     
         2 . The system of  claim 1 , wherein
 the heat collector includes a heat collecting pipe that configures a part of the heat medium pipe, and a reflecting mirror configured to condense the sunray to heat the heat medium in the heat collecting pipe, and   the controller controls the heating of the heat medium by rotating and driving the reflecting mirror.   
     
     
         3 . The system of  claim 2 , wherein
 the controller controls the heat collector so that the reflecting mirror tracks the sun, when the temperature of the heat medium measured by the temperature sensor is lower than a predetermined upper limit temperature, and   the controller controls the heat collector so that the reflecting mirror stops tracking the sun and the reflecting mirror is set to face a direction not to condense the sunray to the heat collecting pipe, when the temperature of the heat medium measured by the temperature sensor is higher than the upper limit temperature.   
     
     
         4 . The system of  claim 1 , wherein the controller controls a heating amount of the heat medium per unit flow rate by changing a flow rate of the heat medium flowing through the heat medium pipe. 
     
     
         5 . The system of  claim 4 , wherein
 the controller adjusts the flow rate of the heat medium to a first flow rate, when the temperature of the heat medium measured by the temperature sensor is lower than a predetermined upper limit temperature, and   the controller adjusts the flow rate of the heat medium to a second flow rate that is higher than the first flow rate, when the temperature of the heat medium measured by the temperature sensor is higher than the upper limit temperature.   
     
     
         6 . The system of  claim 1 , wherein the controller decreases a heating amount of the heat medium per unit flow rate to be smaller than that in a case where the temperature of the heat medium is lower than a predetermined upper limit temperature, when the temperature of the heat medium measured by the temperature sensor is higher than the upper limit temperature. 
     
     
         7 . The system of  claim 1 , wherein
 the heat medium pipe includes a first portion covered with a transparent tube, and a second portion covered with a heat reserving material, positioned downstream of the first portion and positioned upstream of the initial bent portion, and   the temperature sensor measures the temperature of the heat medium in the second portion.   
     
     
         8 . The system of  claim 1 , wherein
 the heat medium pipe includes a first portion covered with a transparent tube, and a second portion covered with a heat reserving material, positioned downstream of the first portion and positioned upstream of the initial bent portion, and a third portion positioned between the first portion and the second portion, and   the temperature sensor measures the temperature of the heat medium in the second portion, in the third portion, or on a boundary between the second portion and the third portion.   
     
     
         9 . The system of  claim 1 , wherein the temperature sensor measures the temperature of the heat medium at the position that is nearer to the reflecting mirror than a center axis of the heat collecting pipe. 
     
     
         10 . A method of controlling a solar heat collecting system comprising:
 a heat collector configured to heat a heat medium by a sunray;   a heater configured to heat a heating target fluid by the heat medium; and   a heat medium pipe configured to circulate the heat medium between the heat collector and the heater;   the method comprising:   measuring a temperature of the heat medium flowing from the heat collector toward the heater, at a position located upstream of an initial bent portion of the heat medium pipe in a region where the heat medium pipe extends from the heat collector toward the heater; and   controlling heating of the heat medium in accordance with the temperature of the heat medium measured at the position located upstream of the initial bent portion.   
     
     
         11 . An apparatus of controlling a solar heat collecting system comprising:
 a heat collector configured to heat a heat medium by a sunray;   a heater configured to heat a heating target fluid by the heat medium; and   a heat medium pipe configured to circulate the heat medium between the heat collector and the heater;   the apparatus comprising:   a first signal outputting module configured to measure a temperature of the heat medium flowing from the heat collector toward the heater, at a position located upstream of an initial bent portion of the heat medium pipe in a region where the heat medium pipe extends from the heat collector toward the heater, and to output a first signal including the measured temperature of the heat medium; and   a second signal outputting module configured to output a second signal to control heating of the heat medium, in accordance with the temperature of the heat medium included in the first signal.