The invention discloses an anti-downdraft control method for a gas water heater. The control method comprises the following steps that when the gas water heater is in a non-working state, a temperature measuring module detects the temperature of an external environment in real time and transmits the temperature to a controller, the controller opens or closes an anti-downdraft module arranged on anexhaust channel of the gas water heater according to the received temperature information. The invention further discloses the gas water heater with a downdraft prevention function. According to thecontrol method, the downdraft prevention module is arranged on the exhaust channel of the gas water heater, the temperature measuring module is installed in the environment of the gas water heater, and the controller controls the downdraft prevention module to be opened or closed according to the temperature detected by the temperature measuring module, so that normal work of the gas water heateris guaranteed.

Anti-downdraft control method of gas water heater and gas water heater

The invention provides an eye eyesight judgement system and method based on an eccentric photorefraction technology. The eye eyesight judgement system comprises an eccentric photorefraction module, animage synthesis module and an image recognition module, wherein the eccentric photorefraction module is used for emitting a light ray into an eye pupil retina of a user, and receiving returned lightray data to transmit to the image synthesis module, the image synthesis module is used for generating eye images according to the light ray data transmitted by the eccentric photorefraction module, and transmitting to the image recognition module, and the image recognition module is used for judging whether measured eyes of the eye images corresponding to the user are suffered from emmetropia, myopia or strabismus or not according to the eye images transmitted by the image synthesis module.

Eye eyesight judgement system and method based on eccentric photorefraction technology

The invention relates to a forced exhaust type gas heating control mechanism. The forced exhaust type gas heating control mechanism comprises a forced exhaust type gas heating assembly, a visibility analysis facility and a water quantity switching facility. The forced exhaust type gas heating assembly comprises a fan switch, a controller, a transformer, a gas proportioning valve, a water flow sensor, an operation key panel, a combustor and a fan. The fan switch is connected with the fan and used for controlling the fan to be started or stopped. The transformer is arranged above the gas proportioning valve. The visibility analysis facility is used for identifying a water vapor region and a water-vapor-free region in a successive filtering image on the basis of water vapor imaging features,and determining the site visibility on the basis of the ratio of the water-vapor-free region to the successive filtering image, wherein the site visibility is proportional to the ratio. The water quantity switching facility is connected with a bathing sprinkler head arranged for the forced exhaust type gas heating assembly, and is used for receiving the site visibility and determining the real-time water yield of the bathing sprinkler head at the unit interval on the basis of the site visibility, wherein the bathing sprinkler head is arranged for the forced exhaust type gas heating assembly. By means of the forced exhaust type gas heating control mechanism, the self-adaptive control capacity of a forced exhaust type gas heater is improved.

Li Hongwei

Papers

Forced exhaust type gas heating control mechanism