CN111174444A - Control method for intelligent preheating of zero-cold-water heater - Google Patents

Abstract

The invention discloses a control method for intelligent preheating of a zero-cold-water heater, which comprises the following steps of: s1, recording the primary water flow L required by the primary zero cold water preheating of the water heater₀(ii) a S2, when the water flow in the circulating pipeline reaches the set temperature T during the preheating again_{Setting up}Then, the circulating water flow L generated in the preheating process is calculated₁(ii) a At the same time, the return water temperature T is collected_{Return water}When the return water temperature T is_{Return water}Greater than a set temperature T_{Setting up}Then, the process proceeds to S3; s3, according to the primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopThe relationship (2) judges whether or not the warm-up is completed. The invention passes through the primary water flow L₀And the flow rate L of the circulating water₁Or the inlet water temperature T_{Inflow water}And a stopping temperature T_StopThe preheating is judged to be finished, and the problem that the cold water pipe in the zero-cold-water preheating is full of hot water is effectively solved.

Description

Control method for intelligent preheating of zero-cold-water heater

Technical Field

The invention belongs to the technical field of water heaters, and particularly relates to a control method for intelligent preheating of a zero-cold-water heater.

Background

The zero-cold-water gas water heater has become a trend in the water heater industry because the zero-cold-water gas water heater can realize that hot water can be used immediately after being started, and when the preheating function is started, a built-in circulating pump runs to drive water stored in an external hot water pipe and a water return pipe to circularly flow and realize preheating. The specific process of zero-cold water is as follows: and (3) starting a zero-cold-water function under the condition of no boiled water, starting a water pump in the water heater, enabling hot water pipeline water to flow out through a water outlet pipe of the water heater after starting, enabling the outflow water to flow back to the water heater through a water return pipeline to form a circulating pipeline, starting combustion heating after the water heater detects a water flow signal, and heating all water in the whole circulating pipeline to a set temperature after 3-5 minutes to finish a zero-cold-water preheating process.

The zero cold water preheating process of the existing gas water heater mostly stops preheating when the water temperature reaches the target temperature, and at the moment, a cold water pipe is used as a water return pipe for circulating heating, so that the whole cold water pipeline is filled with hot water. When the user uses cold water, hot water flows out, and the user needs to wait for a long time to use the cold water, which causes energy waste.

Disclosure of Invention

In view of the above, the present invention provides a control method for intelligent preheating of zero-cold water heater, which uses primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopThe preheating is judged to be finished, and the problem that the cold water pipe in the zero-cold-water preheating is full of hot water is effectively solved.

The invention adopts the technical scheme that a control method for intelligent preheating of a zero-cold-water heater comprises the following steps:

s1, recording the primary water flow L required by the primary zero cold water preheating of the water heater₀；

S2, when the gas water heater is preheated again, when the temperature of the water flow in the circulating pipeline reaches the set temperature T_{Setting up}Then, the circulating water flow L generated in the preheating process is calculated₁；

At the same time, the return water temperature T is collected_{Return water}When the return water temperature T is_{Return water}Greater than a set temperature T_{Setting up}When the temperature of the water is higher than the set temperature,proceeding to S3;

s3, according to the primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopJudging whether preheating is finished or not according to the relation;

wherein the stop temperature T_StopFor determining whether the water flow is heated to a steady state by setting a temperature T_{Setting up}And inlet water temperature T_{Inflow water}To be determined.

Specifically, the primary water flow needed by the primary zero cold water preheating of the water heater is recorded and is taken as the primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopAny one of the two relations is used as a judgment condition for judging whether the preheating is finished or not, so that the condition that the cold water pipe is filled with hot water due to excessive preheating is effectively avoided.

Preferably, in the step S3, the flow rate L is determined according to the primary water flow₀And the flow rate L of the circulating water₁Relationship (c) and inlet water temperature T_{Inflow water}And a stopping temperature T_StopJudging whether the preheating is finished or not according to the relation of (1), specifically:

when the circulating water flow L₁Satisfies the formula (1) or the inlet water temperature T_{Inflow water}Continuously above the stopping temperature T_StopWhen the preheating is finished, preheating is finished;

L₁≥(50％～60％)*L₀(1)。

thus, when the zero cold water function of the water heater is used for the first time, the temperature T is set_{Setting up}Stopping temperature T_StopAnd the temperature T of the inlet water_{Inflow water}Three factors, recording the cumulative initial water flow L after preheating₀Namely, the accumulated water flow of a large cycle is completed in the preheating process, and in order to avoid the situation that the cold water pipe is filled with hot water in the subsequent preheating process, the total water amount preheated again is calculated according to the accumulated water flow of the primary preheating, namely, when the circulating water flow L is₁≥(50％～60％)*L₀Therefore, no matter the water heater with the two-pipe structure or the three-pipe structure is used, the hot water pipe can be effectively ensured to be filled with hot waterAnd the cold water pipe is not filled with hot water.

Preferably, the inlet water temperature T_{Inflow water}Continuously above the stopping temperature T_StopThe method specifically comprises the following steps:

temperature T of inlet water_{Inflow water}Is greater than the stopping temperature T for at least 5s_Stop。

Thus, by judging the inlet water temperature T_{Inflow water}Whether it lasts at least 5s greater than the stop temperature T_StopThereby judging whether the water temperature is stable or not, and judging whether the preheating can be stopped or not.

Preferably, in the step S1, the water flow L required for the initial preheating of the zero-cold-water heater is recorded₀The method specifically comprises the following steps:

s11, starting the preheating function and inputting the set temperature T_{Setting up}And a stopping temperature T_StopPreheating is carried out;

in the specific embodiment, the preheating process of the initial zero cold water preheating is as follows:

s111, starting a preheating function and inputting a set temperature T_{Setting up}And a stopping temperature T_Stop；

S112, the water pump runs, and whether the ignition condition is met or not is judged, namely whether the water flow reaches more than 2.5L/min within 8S or not is judged; if so, opening the gas valve and igniting the water heater to work; if not, alarming abnormally, namely alarming when the water pump is abnormal or the pipeline is blocked and the like;

s113, reaching the set temperature T_{Setting up}Calculating and recording the accumulated circulating water flow;

s114, judging the backwater temperature T_{Return water}Whether or not it is higher than the set temperature T_{Setting up}If yes, entering the next step, otherwise, entering S113;

here, the return water temperature T_{Return water}The water temperature is the water temperature on one side of the water return pipeline close to the water heater, namely the water temperature when the water is heated and then circulates back to the water heater in the preheating process; thus, by judging the backwater temperature T_{Return water}Whether or not it is higher than the set temperature T_{Setting up}For ensuring that the flow of water heated in the preheating process completes a complete cycle, i.e. the heated water returns from the return pipeTo a water heater.

S115, judging the inlet water temperature T_{Inflow water}Whether it lasts at least 5s greater than the stop temperature T_StopIf yes, entering the next step, otherwise, entering S113;

thus, by judging the inlet water temperature T_{Inflow water}Whether or not to continue to be greater than the stopping temperature T for at least 5s_StopThe device is used for determining whether a stable hot water state is reached or not so as to judge whether preheating is finished or not;

s116, stopping preheating, closing a gas valve, extinguishing the gas valve, calculating and recording the total accumulated water flow before 5S, namely the primary water flow L in the primary preheating process₀；

Therefore, after the water temperature reaches a stable state, the accumulated water flow before 5s is calculated, namely the water flow of a complete cycle in preheating.

S12, completing preheating, closing the gas valve, extinguishing the gas valve, and calculating the accumulated water flow in the primary preheating process, namely the primary water flow L₀。

The primary preheating specifically refers to: before the user uses the preheating function of the water heater, the power-off time of the water heater exceeds 30 min.

In the specific embodiment, the power is cut off for more than 30min before the user uses the water heater, and the water heater is used for the first time when the zero cold water preheating function of the water heater is used again; the water heater is started by first power-on of the water heater which is powered off for a long time, and is not particularly used for the first time of a new water heater.

Preferably, the stop temperature T in S3_StopDetermined by the following equation:

when T is_{Inflow water}≤T_{Setting up}At-15 ℃ T_Stop＝T_{Setting up}-10℃；

When T is_{Setting up}-15℃<T_{Inflow water}<T_{Setting up}At-10 ℃ T_Stop＝T_{Setting up}-5℃；

When T is_{Inflow water}≥T_{Setting up}At-10 ℃ T_Stop＝T_{Inflow water}+(5～10)℃。

Preferably, when T_{Inflow water}≥T_{Setting up}At-10 ℃ T_Stop＝T_{Inflow water}+5℃。

In the specific embodiment, when T is_{Inflow water}≥T_{Setting up}At-10 ℃ T_Stop＝T_{Inflow water}+ (5-10) DEG C, preferably T_Stop＝T_{Inflow water}+5 ℃ where the temperature T of the feed water is_{Inflow water}Is the initial inlet water temperature, i.e. the inlet water temperature at which preheating is started this time, i.e. when T_{Inflow water}≥T_{Setting up}At-10 ℃ through the initial inlet water temperature T_{Inflow water}To determine the stopping temperature T_Stop. Thus, when the zero cold water preheating function of the gas water heater is used for the first time in summer, the inlet water temperature T is higher_{Inflow water}Higher and set temperature T_{Setting up}The difference between the two is small, the two are close, misjudgment can be caused, the actual cycle does not complete a large cycle, and preheating is stopped in advance; therefore, when it is to be used for the first time, T is set_Stop＝T_{Inflow water}And +/-5-10 ℃, and the preheating is stopped when a large cycle is ensured. For example, in summer, the inlet water temperature may reach 33 ℃ at times, if the set temperature T is reached_{Setting up}At 35 ℃, the two are relatively close to each other, which may cause erroneous judgment.

Preferably, the primary water flow rate L in S1₀The average value of the sum of the accumulated water flow of the first two times or the first three times when the zero cold water preheating function of the water heater is used for the first time.

Preferably, the total amount of water preheated in S2 is L₁≥50％*L₀。

The invention has the beneficial effects that: the invention uses the primary water flow L required by the primary preheating process of the water heater with the function of preheating zero cold water for the primary use₀Recording and preheating the inlet water temperature T_{Inflow water}And a stop temperature T_StopComparing to ensure the stability of hot water in the preheating process; at the same time, the invention uses the primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopEither of the above relationships is used as a judgment condition for stopping the preheating, and the judgment condition can be set in the hot water pipeWhen the cold water pipe is full of hot water, the preheating is stopped, and the problem that the cold water pipe is full of hot water in the zero-cold-water preheating mode is effectively solved.

Drawings

FIG. 1 is a flow chart of a method in embodiment 1 of a control method for intelligent preheating of a zero-cold-water heater according to the present invention;

FIG. 2 is a flow chart of the method of embodiment 2 in the control method for intelligent preheating of the zero-cold-water heater of the present invention;

fig. 3 is a flowchart of a method in embodiment 3 of the control method for intelligent preheating of a zero-cold-water heater according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a control method for intelligent preheating of a zero-cold-water heater, which comprises the following steps of:

s1, recording the primary water flow L required by the primary zero cold water preheating of the water heater₀；

S2, when the gas water heater is preheated again, when the temperature of the water flow in the circulating pipeline reaches the set temperature T_{Setting up}Then, the circulating water flow L generated in the preheating process is calculated₁；

At the same time, the return water temperature T is collected_{Return water}When the return water temperature T is_{Return water}Greater than a set temperature T_{Setting up}Then, the process proceeds to S3;

s3, according to the primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopJudging whether preheating is finished or not according to the relation;

wherein the stop temperature T_StopFor determining whether the water flow is heated to a steady state by setting a temperature T_{Setting up}And inlet water temperature T_{Inflow water}To be determined.

Example 1

The embodiment provides a control method for intelligent preheating of a zero-cold-water heater, as shown in fig. 1, including the following steps:

s1, recording the primary water flow L required by the primary zero cold water preheating of the water heater₀；

Here, the user is powered off for more than 30min before using the water heater, and the water heater is used for the first time when the zero cold water preheating function of the water heater is used again; the water heater is started by electrifying for the first time after long-time power failure, and is not particularly used for the first time of a new water heater;

s2, when the gas water heater is preheated again, when the temperature of the water flow in the circulating pipeline reaches the set temperature T_{Setting up}Then, the circulating water flow L generated in the preheating process is calculated₁；

Set temperature T_{Setting up}The temperature to be set by a user according to the requirement, namely the temperature to be reached by the water flow in the actual use of the user is generally 35-50 ℃, and the stop temperature T is set by the user_StopThe water flow heating device is used for judging whether the water flow is heated to a stable state or not so as to ensure the use of a user;

at the same time, the return water temperature T is collected_{Return water}When the return water temperature T is_{Return water}Greater than a set temperature T_{Setting up}Then, the process proceeds to S3;

thus, by detecting the backwater temperature T_{Return water}Whether water flow passes through a circulation in the preheating process or not can be judged, the water flow enters the water heater through the water return pipeline again, and when the water temperature enters the water heater through the water return pipeline, namely the water return temperature T_{Return water}Reaches a set temperature T_{Setting up}Indicating that the water has been heated.

For general water heaters and household pipelines, 20s is the shortest time for hot water to return to the gas water heater through the water return pipeline again, so that the temperature T of the inlet water can be judged after the hot water is combusted for 20s_{Inflow water}Whether or not it lasts for 5s greater than the stop temperature T_Stop；

S3, according to the primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperatureT_StopJudging whether preheating is finished or not according to the relation;

specifically, when the circulating water flow L is₁Satisfies the formula (1) or the inlet water temperature T_{Inflow water}Greater than said stop temperature T for at least 5s_StopWhen the preheating is finished, preheating is finished;

L₁≥(50％～60％)*L₀(1)。

for a water heater with a two-pipe structure, the lengths of the hot water pipe and the cold water pipe are the same, and the circulating water flow L is equal₁With the primary water flow rate L₀May be L₁≥50％*L₀。

Wherein the stop temperature T_StopFor determining whether the water flow is heated to a steady state by setting a temperature T_{Setting up}And inlet water temperature T_{Inflow water}To determine;

stopping temperature T_StopDetermined by the following equation:

when T is_{Inflow water}≤T_{Setting up}At-15 ℃ T_Stop＝T_{Setting up}-10℃；

When T is_{Setting up}-15℃<T_{Inflow water}<T_{Setting up}At-10 ℃ T_Stop＝T_{Setting up}-5℃；

When T is_{Inflow water}≥T_{Setting up}At-10 ℃ T_Stop＝T_{Inflow water}+ (5-10) DEG C, preferably T_Stop＝T_{Inflow water}+5 ℃ where the temperature T of the feed water is_{Inflow water}Is the initial inlet water temperature before preheating is started.

Thus, when the zero cold water preheating function of the gas water heater is used for the first time in summer, the inlet water temperature T is higher_{Inflow water}Higher and set temperature T_{Setting up}The difference between the two is small, the two are close, misjudgment can be caused, the actual cycle does not complete a large cycle, and preheating is stopped in advance; therefore, when it is to be used for the first time, T is set_Stop＝T_{Inflow water}And +/-5-10 ℃, and the preheating is stopped when a large cycle is ensured. For example, in summer, the inlet water temperature may reach 33 ℃ at times, if the set temperature T is reached_{Setting up}At 35 ℃, the two are relatively close to each other, which may cause erroneous judgment.

To improve the accuracy of the preheating process, the primary water flow rate L₀The average value of the sum of the cumulative water flow of the first two or three times when the zero cold water preheating function of the water heater is used for the first time is adopted.

The working principle is as follows: when the control method of the embodiment is used, the primary water flow L required by the primary zero cold water preheating of the water heater is firstly recorded₀Namely the accumulated water flow for preheating is completed, and when the water is preheated again, the circulating water flow L in the preheating process is used₁With primary water flow L₀The relationship of (1): l is₁≥(50％～60％)*L₀Or temperature T of the feed water_{Inflow water}Greater than said stop temperature T for at least 5s_StopWhether the preheating is finished or not is judged by either of the two methods, namely the temperature of the water flow is stable or the preheating circulating water amount reaches 50% -60% of the accumulated water flow after the preheating is finished in the primary preheating process, so that the hot water pipe is filled with the hot water and the preheating is finished.

The primary water flow L required by the primary preheating process of the water heater with the zero cold water preheating function is used for the first time in the embodiment₀Recording to obtain the flow L of the circulating water for filling the hot water pipe with hot water in the subsequent preheating process₁And by adjusting the inlet water temperature T in the preheating process_{Inflow water}And a stop temperature T_StopComparing to ensure the stability of hot water in the preheating process; thus, the primary water flow rate L is used in the present embodiment₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopAny one of the two relations is used as a judgment condition for stopping preheating, the preheating can be stopped when the hot water pipe is filled with hot water, and the problem that the cold water pipe is filled with hot water in zero cold water preheating is effectively solved.

Example 2

The same procedure as that of embodiment 1, except that the preheating process of the zero cold water preheating function of the water heater for the first time is refined, as shown in fig. 2, and the method comprises the following steps:

s1, recording the initial zero of the water heaterPrimary water flow L required for cold water preheating₀；

The method specifically comprises the following steps:

s11, starting the preheating function and inputting the set temperature T_{Setting up}And a stopping temperature T_StopPreheating is carried out;

s12, after preheating is finished, closing the gas valve, extinguishing the gas valve, and calculating the accumulated water flow in the primary preheating process, namely the primary water flow L₀。

S2, when the gas water heater is preheated again, when the temperature of the water flow in the circulating pipeline reaches the set temperature T_{Setting up}Then, the circulating water flow L generated in the preheating process is calculated₁；

Set temperature T_{Setting up}The temperature to be set by a user according to the requirement, namely the temperature to be reached by the water flow in the actual use of the user is generally 35-50 ℃, and the stop temperature T is set by the user_StopThe water flow heating device is used for judging whether the water flow is heated to a stable state or not so as to ensure the use of a user;

at the same time, the return water temperature T is collected_{Return water}When the return water temperature T is_{Return water}Greater than a set temperature T_{Setting up}Then, the process proceeds to S3;

s3, according to the primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopJudging whether preheating is finished or not according to the relation;

specifically, when the circulating water flow L is₁Satisfies the formula (1) or the inlet water temperature T_{Inflow water}Greater than said stop temperature T for at least 5s_StopWhen the preheating is finished, preheating is finished;

L₁≥(50％～60％)*L₀(1)。

for a water heater with a two-pipe structure, the lengths of the hot water pipe and the cold water pipe are the same, and the circulating water flow L is equal₁With the primary water flow rate L₀May be L₁≥50％*L₀。

Wherein the stop temperature T_StopFor determining whether the water flow is heated to a steady state by setting a temperature T_{Setting up}And inlet waterTemperature T_{Inflow water}To determine;

stopping temperature T_StopDetermined by the following equation:

when T is_{Inflow water}≤T_{Setting up}At-15 ℃ T_Stop＝T_{Setting up}-10℃；

When T is_{Setting up}-15℃<T_{Inflow water}<T_{Setting up}At-10 ℃ T_Stop＝T_{Setting up}-5℃；

When T is_{Inflow water}≥T_{Setting up}At-10 ℃ T_Stop＝T_{Inflow water}+ (5-10) DEG C, preferably T_Stop＝T_{Inflow water}+5℃。

Thus, when the zero cold water preheating function of the gas water heater is used for the first time in summer, the inlet water temperature T is higher_{Inflow water}Higher and set temperature T_{Setting up}The difference between the two is small, the two are close, misjudgment can be caused, the actual cycle does not complete a large cycle, and preheating is stopped in advance; therefore, when it is to be used for the first time, T is set_Stop＝T_{Inflow water}And +/-5-10 ℃, and the preheating is stopped when a large cycle is ensured. For example, in summer, the inlet water temperature may reach 33 ℃ at times, if the set temperature T is reached_{Setting up}At 35 ℃, the two are relatively close to each other, which may cause erroneous judgment.

The working principle is as follows: when the control method of the embodiment is used, the primary water flow L required by the primary zero cold water preheating of the water heater is firstly recorded₀Namely the accumulated water flow for preheating is completed, and when the water is preheated again, the circulating water flow L in the preheating process is used₁With primary water flow L₀The relationship of (1): l is₁≥(50％～60％)*L₀Or temperature T of the feed water_{Inflow water}Greater than said stop temperature T for at least 5s_StopWhether the preheating is finished or not is judged by either of the two methods, namely the temperature of the water flow is stable or the preheating circulating water amount reaches 50% -60% of the accumulated water flow after the preheating is finished in the primary preheating process, so that the hot water pipe is filled with the hot water and the preheating is finished.

This example is through the heat to the function of preheating zero cold water for the first timePrimary water flow L required for primary preheating process of water heater₀Recording to obtain the flow L of the circulating water for filling the hot water pipe with hot water in the subsequent preheating process₁And by adjusting the inlet water temperature T in the preheating process_{Inflow water}And a stop temperature T_StopComparing to ensure the stability of hot water in the preheating process; thus, the primary water flow rate L is used in the present embodiment₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopAny one of the two relations is used as a judgment condition for stopping preheating, the preheating can be stopped when the hot water pipe is filled with hot water, and the problem that the cold water pipe is filled with hot water in zero cold water preheating is effectively solved.

Example 3

The same process as that of embodiment 1 or embodiment 2, except that the preheating process of the zero cold water preheating function of the water heater for the first time and the process of preheating again are refined and optimized, as shown in fig. 3, the method comprises the following steps:

s1, recording the primary water flow L required by the primary zero cold water preheating of the water heater₀；

The method specifically comprises the following steps:

s11, when the zero cold water preheating function of the water heater is used for the first time, the water heater is powered on, the preheating function is started, and the set temperature T is input_{Setting up}And a stopping temperature T_StopPreheating is carried out;

s111, starting a preheating function and inputting a set temperature T_{Setting up}And a stopping temperature T_Stop；

Stopping temperature T_StopBy setting the temperature T_{Setting up}And inlet water temperature T_{Inflow water}To determine; set temperature T_{Setting up}The temperature to be set by a user according to the requirement, namely the temperature to be reached by the water flow in the actual use of the user is generally 35-50 ℃, and the stop temperature T is set by the user_StopUsed for judging whether the water flow is heated to a stable state or not, thereby ensuring the use of users.

Here, according to the set temperature T_{Setting up}And inlet water temperature T_{Inflow water}To determine the stopping temperature T_StopEither is provided withThe water flow in the preheating process is ensured to complete a complete cycle and be heated integrally, and the temperature of the water flow can be ensured to be stable;

stopping temperature T_StopThe specific determination process is determined by the following formula:

when T is_{Inflow water}≤T_{Setting up}At-15 ℃ T_Stop＝T_{Setting up}-10℃；

When T is_{Setting up}-15℃<T_{Inflow water}<T_{Setting up}At-10 ℃ T_Stop＝T_{Setting up}-5℃；

When T is_{Inflow water}≥T_{Setting up}At-10 ℃ T_Stop＝T_{Inflow water}+ (5-10) DEG C, preferably T_Stop＝T_{Inflow water}+5℃。

Thus, when the zero cold water preheating function of the gas water heater is used for the first time in summer, the inlet water temperature T is higher_{Inflow water}Higher and set temperature T_{Setting up}The difference between the two is small, the two are close, misjudgment can be caused, the actual cycle does not complete a large cycle, and preheating is stopped in advance; therefore, when it is to be used for the first time, T is set_Stop＝T_{Inflow water}And +/-5-10 ℃, and the preheating is stopped when a large cycle is ensured. For example, in summer, the inlet water temperature may reach 33 ℃ at times, if the set temperature T is reached_{Setting up}At 35 ℃, the two are relatively close to each other, which may cause erroneous judgment.

S112, the water pump runs, and whether the ignition condition is met or not is judged, namely whether the water flow reaches more than 2.5L/min within 8S or not is judged;

if so, opening the gas valve and igniting the water heater to work;

if not, an abnormal alarm is given, namely the conditions such as water pump abnormality or pipeline blockage can occur, and an alarm is given.

S113, reaching the set temperature T_{Setting up}Calculating and recording the accumulated circulating water flow;

s114, judging the backwater temperature T_{Return water}Whether or not it is higher than the set temperature T_{Setting up}；

If so, the next step is carried out,i.e. comparing the inlet water temperature T_{Inflow water}Whether or not it lasts for 5s greater than the stop temperature T_StopSo as to judge whether the hot water is stable;

if not, entering S113, then recording the accumulated water flow;

thus, by detecting the backwater temperature T_{Return water}Whether water flow passes through a circulation in the preheating process or not can be judged, the water flow enters the water heater through the water return pipeline again, and when the water temperature enters the water heater through the water return pipeline, namely the water return temperature T_{Return water}Reaches a set temperature T_{Setting up}Indicating that the water has been heated.

For general water heaters and household pipelines, 20s is the shortest time for hot water to return to the gas water heater through the water return pipeline again, so that the temperature T of the inlet water can be judged after the hot water is combusted for 20s_{Inflow water}Whether or not it lasts for 5s greater than the stop temperature T_Stop；

S115, judging the inlet water temperature T_{Inflow water}Whether it lasts at least 5s greater than the stop temperature T_Stop；

If yes, entering S116, stopping preheating, closing a gas valve, and extinguishing;

if not, entering S113, namely continuing to preheat;

thus, by the temperature T of the inlet water_{Inflow water}Whether or not it lasts for 5s greater than the stop temperature T_StopTo determine whether the water temperature is stable, thereby determining whether the preheating can be stopped.

Particularly, by judging the return water temperature T_{Return water}Whether or not it is higher than the set temperature T_{Setting up}The water flow heated in the preheating process is ensured to complete a complete cycle, namely the heated water returns to the water heater from the water return pipeline; then judging the inlet water temperature T_{Inflow water}Whether or not it lasts for 5s greater than the stop temperature T_StopThe method is used for determining whether a stable hot water state is achieved or not so as to judge whether the preheating is finished or not.

S116, stopping preheating, closing a gas valve, extinguishing the gas valve, calculating and recording the accumulated water flow sum before 5S, namely the accumulated water flow sum L in the primary preheating process₀。

Here, the cumulative water flow rate sum L₀The average value of the accumulated water flow sum of the first two times or the first three times when the zero cold water preheating function of the water heater is used for the first time can be ensured₀The accuracy of (2).

S12, completing preheating, closing the gas valve, extinguishing the gas valve, and calculating the accumulated water flow in the primary preheating process, namely the primary water flow L₀；

S2, when the gas water heater is preheated again, when the temperature of the water flow in the circulating pipeline reaches the set temperature T_{Setting up}Then, the circulating water flow L generated in the preheating process is calculated₁；

At the same time, the return water temperature T is collected_{Return water}When the return water temperature T is_{Return water}Greater than a set temperature T_{Setting up}Then, the process proceeds to S3;

the method specifically comprises the following steps:

s21, starting the preheating function again, operating the water pump, and judging whether the ignition condition is met, namely whether the water flow reaches more than 2.5L/min within 8S;

if so, opening the gas valve and igniting the water heater to work;

if not, an abnormal alarm is given, namely the conditions such as water pump abnormality or pipeline blockage can occur, and an alarm is given.

S22, reaching the set temperature T_{Setting up}Then, the circulating water flow L generated in the preheating process is calculated₁；

S23, collecting the backwater temperature T_{Return water}And judging the return water temperature T_{Return water}Whether or not it is greater than the set temperature T_{Setting up}；

If yes, go to S3;

otherwise, returning to S22;

s3, according to the primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopJudging whether preheating is finished or not according to the relation;

the method specifically comprises the following steps:

s31, judging the inlet water temperature T_{Inflow water}Whether or not toFor 5s greater than the stopping temperature T_Stop；

If yes, entering S33, stopping preheating, closing the gas valve, and extinguishing;

if not, the next step is carried out, namely the flow L of the circulating water is judged₁With primary water flow L₀By the relationship of the circulating water flow L₁As another judgment condition whether the preheating is completed;

thus, by the temperature T of the inlet water_{Inflow water}Whether or not it lasts for 5s greater than the stop temperature T_StopTo determine whether the water temperature is stable, thereby determining whether the preheating can be stopped.

S32, judging whether the circulating water flow L1 meets the formula: l is₁≥(50％～60％)*L₀；

If yes, entering S33, stopping preheating, closing the gas valve, and extinguishing;

if not, entering S22, namely, continuing preheating;

thus, when the zero cold water function of the water heater is used for the first time, the temperature T is set_{Setting up}Stopping temperature T_StopAnd the temperature T of the inlet water_{Inflow water}Recording the accumulated water flow after preheating, namely the accumulated water flow after completing one large cycle in the preheating process, and using the initial water flow L for initial preheating to avoid filling hot water in a cold water pipe in the subsequent preheating process₀As a criterion for determining the flow rate of the recirculated water for reheating, i.e. L₁≥(50％～60％)*L₀Therefore, whether the water heater with the two-pipe structure or the three-pipe structure is used, the hot water pipe can be effectively filled with hot water, and the cold water pipe is not filled with hot water.

For a two-pipe water heater, the circulating water flow rate L₁≥50％*L₀And (4) finishing.

And S33, stopping preheating, closing the gas valve, extinguishing the gas valve and completing the preheating process.

The working principle is as follows: when the control method of the embodiment is used, the temperature T of the inlet water in the preheating process is adjusted_{Inflow water}And a stop temperature T_StopComparing to determine the completion of the initial zero cold water preheating process and recording the water heaterInitial water flow L required for initial zero cold water preheating₀Namely the accumulated water flow for preheating is completed, and when the water is preheated again, the circulating water flow L in the preheating process is used₁With primary water flow L₀The relationship of (1): l is₁≥(50％～60％)*L₀Or temperature T of the feed water_{Inflow water}Greater than said stop temperature T for at least 5s_StopEither one of the two methods is used for judging whether the preheating is finished, namely the water flow temperature is stable or the preheating circulating water amount reaches 50% -60% of the accumulated water flow, so that the hot water pipe is filled with the hot water and the preheating is finished.

The primary water flow L required by the primary preheating process of the water heater with the zero cold water preheating function is used for the first time in the embodiment₀Recording to obtain the flow L of the circulating water for filling the hot water pipe with hot water in the subsequent preheating process₁And by adjusting the inlet water temperature T in the preheating process_{Inflow water}And a stop temperature T_StopComparing to ensure the stability of hot water in the preheating process; thus, the primary water flow rate L is used in the present embodiment₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopAny one of the two relations is used as a judgment condition for stopping preheating, the preheating can be stopped when the hot water pipe is filled with hot water, and the problem that the cold water pipe is filled with hot water in zero cold water preheating is effectively solved.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (9)

1. A control method for intelligent preheating of a zero-cold-water heater is characterized by comprising the following steps:

s1, recording the primary water flow L required by the primary zero cold water preheating of the water heater₀；

S2, gas-fired hot waterWhen the device is preheated again, when the temperature of the water flow in the circulating pipeline reaches the set temperature T_{Setting up}Then, the circulating water flow L generated in the preheating process is calculated₁；

At the same time, the return water temperature T is collected_{Return water}When the return water temperature T is_{Return water}Greater than a set temperature T_{Setting up}Then, the process proceeds to S3;

s3, according to the primary water flow L₀And the flow rate L of the circulating water₁And the inlet water temperature T_{Inflow water}And a stopping temperature T_StopJudging whether preheating is finished or not according to the relation;

wherein the stop temperature T_StopFor determining whether the water flow is heated to a steady state by setting a temperature T_{Setting up}And inlet water temperature T_{Inflow water}To be determined.

2. The method as claimed in claim 1, wherein the step S3 is executed according to the primary water flow L₀And the flow rate L of the circulating water₁Relationship (c) and inlet water temperature T_{Inflow water}And a stopping temperature T_StopJudging whether the preheating is finished or not according to the relation of (1), specifically:

when the circulating water flow L₁Satisfies the formula (1) or the inlet water temperature T_{Inflow water}Continuously above the stopping temperature T_StopWhen the preheating is finished, preheating is finished;

L₁≥(50％～60％)*L₀(1)。

3. the method of claim 2, wherein the inlet water temperature T is controlled by the intelligent preheat of a zero-cold-water heater_{Inflow water}Continuously above the stopping temperature T_StopThe method specifically comprises the following steps:

temperature T of inlet water_{Inflow water}Is greater than the stopping temperature T for at least 5s_Stop。

4. The method for controlling the intelligent preheating of the zero-cold-water heater according to claim 3,recording initial water flow L required by initial preheating of zero-cold-water heater in S1₀The method specifically comprises the following steps:

s11, starting the preheating function and inputting the set temperature T_{Setting up}And a stopping temperature T_StopPreheating is carried out;

s12, after preheating is finished, closing the gas valve, extinguishing the gas valve, and calculating the accumulated water flow in the primary preheating process, namely the primary water flow L₀。

5. The method for controlling the intelligent preheating of the zero-cold-water heater according to claim 4, wherein the primary preheating specifically includes: before the user uses the preheating function of the water heater, the power-off time of the water heater exceeds 30 min.

6. The method for controlling the intelligent preheating of the zero-cold-water heater according to any one of claims 1 to 5, wherein the temperature T is stopped in the step S3_StopDetermined by the following equation:

when T is_{Inflow water}≤T_{Setting up}At-15 ℃ T_Stop＝T_{Setting up}-10℃；

When T is_{Setting up}-15℃<T_{Inflow water}<T_{Setting up}At-10 ℃ T_Stop＝T_{Setting up}-5℃；

When T is_{Inflow water}≥T_{Setting up}At-10 ℃ T_Stop＝T_{Inflow water}+(5～10)℃。

7. The method as claimed in claim 6, wherein when T is the time T for intelligent preheating of the zero-cold-water heater_{Inflow water}≥T_{Setting up}At-10 ℃ T_Stop＝T_{Inflow water}+5℃。

8. The method for controlling the intelligent preheating of the zero-cold-water heater according to any one of claims 1 to 5, wherein the primary water flow L in S1 is₀The average value of the sum of the accumulated water flow of the first two times or the first three times when the zero cold water preheating function of the water heater is used for the first time.

9. The method as claimed in claim 8, wherein the flow rate of the circulating water for re-preheating in S2 is L₁≥50％*L₀。

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