Patent ID: 9086068
Filing Date: 2015-07-21
Classification: F04D,F23N

Abstract:
1. A method of detecting safety of a water heater, wherein the water heater includes a blower and a combustor, the method comprising the steps of: A. starting the blower, and detecting a speed of the blower after the blower has run for a time wherein gas is not supplied yet; B. comparing the speed of the blower with a first speed range, and then start supplying gas to the combustor when the speed of the blower is within the first speed range, or not supplying gas and stopping the blower when the speed of the blower is beyond the first speed range; and C. detecting a speed of the blower again after the combustor heats water for a certain amount of time, and comparing the speed of the blower with a second speed range, and then continuing to supply gas to the combustor and keeping the speed of the blower when the speed of the blower is within the second speed range, or stopping to supply gas when the speed of the blower is beyond the second speed range; wherein a first theoretical speed falls in the first speed range, and the first theoretical speed is an expected speed of the blower before the combustor starts to heat water, and the blower has run for a certain amount of time; wherein a second theoretical speed falls in the second speed range, and the second theoretical speed is an expected speed of the blower when the combustor burns under an optimal air-gas ratio; wherein the first speed range is between a first lowest acceptable speed and a first highest acceptable speed of the blower before ignition; and wherein the second speed range is between a second lowest acceptable speed and a second highest acceptable speed of the blower while the combustor is burning gas.