초록 ▼

A method of operating a fuel cell cogeneration system comprises the steps of cooling a fuel cell by circulating an internal heat transfer medium through the fuel cell while the fuel cell is generating electric power, storing an external heat transfer medium in a heat utilization portion, detecting r

A method of operating a fuel cell cogeneration system comprises the steps of cooling a fuel cell by circulating an internal heat transfer medium through the fuel cell while the fuel cell is generating electric power, storing an external heat transfer medium in a heat utilization portion, detecting remaining calories of the heat utilization portion by a first detector provided at the heat utilization portion, increasing a temperature of the fuel cell to an operating temperature by carrying out a first temperature increasing operation, and increasing the temperature of the fuel cell to the operating temperature by carrying out a second temperature increasing operation.

대표청구항 ▼

What is claimed is: 1. A method of operating a fuel cell cogeneration system, the method comprising the steps of: (A) cooling a fuel cell by circulating an internal heat transfer medium through the fuel cell while the fuel cell is generating electric power; (B) storing an external heat transfer med

What is claimed is: 1. A method of operating a fuel cell cogeneration system, the method comprising the steps of: (A) cooling a fuel cell by circulating an internal heat transfer medium through the fuel cell while the fuel cell is generating electric power; (B) storing an external heat transfer medium in a heat utilization portion, the external heat transfer medium having recovered heat from the internal heat transfer medium via a heat exchanger provided at an internal passage through which the internal heat transfer medium circulates; (C) detecting remaining calories of the heat utilization portion by a first detector provided at the heat utilization portion; (D) increasing a temperature of the fuel cell to an operating temperature by carrying out a first temperature increasing operation comprised of increasing the temperature of the fuel cell by circulating, when the remaining calories are at a threshold or more at the time of start-up, the internal heat transfer medium to which the heat is transferred from the external heat transfer medium via the heat exchanger; and (E) increasing the temperature of the fuel cell to the operating temperature by carrying out a second temperature increasing operation comprised of increasing the temperature of the fuel cell by circulating, when the remaining calories are less than the threshold, the internal heat transfer medium heated by a heater provided at the internal passage. 2. The method according to claim 1, wherein step (D) increases the temperature of the fuel cell by carrying out the first temperature increasing operation as a main operation and the second temperature increasing operation. 3. The method according to claim 1, wherein step (E) increases the temperature of the fuel cell by carrying out the second temperature increasing operation as a main operation and the first temperature increasing operation. 4. The method according to claim 1, wherein step (D) includes the steps of: (D1) detecting a temperature of the external heat transfer medium stored in the heat utilization portion; (D2) increasing the temperature of the fuel cell to the operating temperature by carrying out the first temperature increasing operation when the remaining calories are the threshold or more, and the temperature of the external heat transfer medium detected in the step (D1) is the operating temperature or higher; and (D3) increasing the temperature of the fuel cell to the operating temperature by carrying out the second temperature increasing operation when the remaining calories are the threshold or more, and the temperature of the external heat transfer medium is lower than the operating temperature. 5. The method according to claim 4, wherein step (D) includes the steps of: (D4) detecting an ambient air temperature outside the fuel cell; (D5) increasing the temperature of the fuel cell to the operating temperature by carrying out the first temperature increasing operation when the remaining calories are the threshold or more, and the temperature of the external heat transfer medium detected in step (D1) is the operating temperature or higher, and increasing the temperature of the fuel cell to the operating temperature by carrying out both the first temperature increasing operation and the second temperature increasing operation when the remaining calories are at the threshold or more, and the temperature of the external heat transfer medium detected in step (D1) is lower than the operating temperature and equal to or higher than the ambient air temperature outside the fuel cell detected in step (D4); and (D6) increasing the temperature of the fuel cell to the operating temperature by carrying out the second temperature increasing operation when the remaining calories are at the threshold or more, and the temperature of the external heat transfer medium is lower than the operating temperature and the ambient air temperature outside the fuel cell detected in step (D4). 6. The method according to claim 1, wherein the threshold includes fuel cell increasing calories required to increase the temperature of the fuel cell to the operating temperature and predetermined calories. 7. The method according to claim 6, wherein the predetermined calories are start time period consumed calories consumed by consumers during a start time period from when the fuel cell starts until a predetermined time elapses. 8. The method according to claim 7, further comprising the steps of: (F1) detecting, by a fourth detector, consumed calories of the external heat transfer medium stored in the heat utilization portion and measuring, by a clock, a time at which the consumed calories are detected; (F2) storing the detected consumed calories and the measured time; and (F3) calculating the start time period consumed calories based on the measured time and the stored consumed calories. 9. The method according to claim 8, wherein step (F3) obtains the start time period consumed calories by calculating an average value of consumed calories for a predetermined period. 10. The method according to claim 8, wherein the predetermined calories include a fixed amount and a correction amount, the method further comprising a step (F4) of changing the correction amount based on the start time period consumed calories calculated in step (F3). 11. The method according to claim 6, further comprising the steps of (F5) detecting an ambient air temperature outside the fuel cell; and (F6) changing the predetermined calories based on the ambient air temperature detected in step (F5). 12. The method according to claim 6, further comprising the steps of (F7) detecting the temperature of the external heat transfer medium to be consumed; and (F8) changing the predetermined calories according to a frequency at which the temperature of the external heat transfer medium detected in step (F7) is not higher than a predetermined value. 13. The method according to claim 1, wherein: the external heat transfer medium is water; and the heat utilization portion is a tank. 14. The method according to claim 13, wherein the tank is a layered hotwater tank. 15. The method according to claim 1, wherein: step (D) increases the temperature of the fuel cell to the operating temperature only by the first temperature increasing operation; and step (E) increases the temperature of the fuel cell to the operating temperature only by the second temperature increasing operation.