Control method and control device of constant-temperature gas water heater

Abstract

The invention discloses a control method and a control device of a constant-temperature gas water heater. The control method includes steps of detecting current water inlet temperature, current water inlet flow and current set water outlet temperature of the water heater and calculating current required heat; comparing the current required heat with rated heat supply of the heater; when the current required heat is higher than the rated heat supply, reducing practical water inlet flow of the heater, and when the current required heat is lower than the rated heat supply, increasing practical water inlet flow of the heater; adjusting opening of a gas proportion valve of the water heater by an PID (proportion integration differentiation) algorithm, and controlling the water heater so as to supply water at constant temperature by the current set water outlet temperature. By the control method and the control device of the constant-temperature gas water heater, the water heater is controlled, water outlet temperature reaches the set temperature, water outlet temperature can be quickly and stably adjusted, and service performance of the water heater is improved.

Description

technical field [0001] The invention belongs to the control technology of water heaters, in particular relates to the control of gas water heaters, and more specifically relates to a control method and a control device for constant temperature gas water heaters. Background technique [0002] An important indicator of a constant temperature gas water heater is that it is required to be able to discharge water according to the temperature set by the user, that is, to ensure a constant temperature of the discharged water. With the rapid development of social economy, existing buildings generally have higher floors and require secondary water supply, resulting in unstable water pressure for users. If the water pressure fluctuates, the water flow rate changes, or the inlet water temperature and the set temperature change, in order to ensure a constant outlet water temperature, it is necessary to change the opening of the gas proportional valve of the gas water heater, thereby cha...

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Problems solved by technology

A problem that exists in this way is that if the temperature difference between the inlet and outlet water is large or the water flow rate is large, even if the opening of the gas proportional valve is opened to the maximum, the constant temperature of the outlet water cannot be guaranteed.

This phenomenon is especially obvious in winter, because the water inlet temperature is low in winter, users often complain that the outlet water temperature does not reach the set temperature, which affects the bathing comfort

Moreover, when the opening of the gas proportional valve is directly adjusted according to the set temperature and the water inlet flow, the process of reaching a constant outlet water temperature is longer and the control speed is slower, which also affects the comfort of the user.

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