CN116147203A

CN116147203A - Gas water heating equipment, preheating cycle control method thereof and readable storage medium

Info

Publication number: CN116147203A
Application number: CN202211712666.0A
Authority: CN
Inventors: 王琼
Original assignee: Vaillant Wuxi Heating Equipment Co Ltd
Current assignee: Vaillant Wuxi Heating Equipment Co Ltd
Priority date: 2022-12-05
Filing date: 2022-12-05
Publication date: 2023-05-23

Abstract

The invention provides a gas water heating device, a preheating cycle control method thereof and a readable storage medium. The preheating cycle control method comprises the following steps: obtaining the average circulating water flow when the circulating water pump operates in the preheating circulating mode; calculating a return water and outlet water temperature difference limit value according to the minimum input load of the equipment and the average circulating water flow, wherein the return water and outlet water temperature difference limit value is the difference between an outlet water temperature threshold value and a return water temperature threshold value; acquiring a backwater temperature threshold according to the backwater and water outlet temperature difference limit value and a preset water outlet temperature threshold; and monitoring the backwater temperature and the water outlet temperature, and stopping combustion when the backwater temperature is greater than or equal to a backwater temperature threshold value or the water outlet temperature is greater than or equal to a preset water outlet temperature threshold value. According to the circulating water flow self-adaptive regulation backwater temperature threshold value, the frequent start and stop of the equipment in the preheating process can be relieved, and meanwhile, the preheating in the circulating pipeline is more sufficient and the temperature distribution is more uniform.

Description

Gas water heating equipment, preheating cycle control method thereof and readable storage medium

Technical Field

The disclosure relates to the field of control of gas water heating equipment, in particular to gas water heating equipment and a control method of preheating circulation of the gas water heating equipment.

Background

Gas water heating plants generally comprise a gas water heater and a gas boiler. The gas water heater is used for supplying domestic hot water such as drinking water, bathing water and the like; and the gas boiler can be used for providing domestic hot water and also can be communicated with a radiator arranged indoors to provide central heating.

In general, when a user needs to use domestic hot water, the user can open the mixing faucet, and the gas water heating equipment is started. During a period of time when the device is just started, cold water stored in the water pipe can be discharged first, so that the use experience of a user is affected. To avoid this problem, current gas water heating apparatuses generally have a preheating circulation mode to circulate cold water in a preheating water pipe during a period when a user does not use hot water, so that the user can use hot water after opening. However, the water flow in the circulation line decreases due to the increase in water resistance after long-term use. When the equipment works at the minimum input load and the circulating water flow is smaller, the water outlet temperature of the equipment can be rapidly increased to reach the temperature threshold value for stopping the operation of the preheating circulation, and at the moment, the equipment stops working. However, the water temperature in the circulation water path does not reach the set temperature of the circulation warm-up uniformly at this time. For example, the water temperature at the water inlet/return port of the device is low, and as the water temperature decreases, the preheating cycle is triggered quickly, and the preheating cycle is repeated so that the burner assembly and the circulating water pump of the device are started frequently, which obviously affects the service life of the device, and uneven water heating and cooling in the circulating water channel can be caused, so that a user can feel suddenly heated when using the hot water, and the comfort level is reduced.

Disclosure of Invention

To overcome the problems in the background art, the present disclosure provides a gas water heating apparatus, a preheating cycle control method thereof, and a readable storage medium.

A first aspect of an embodiment of the present disclosure provides a preheating cycle control method of a gas water heating apparatus, including: obtaining the average circulating water flow when the circulating water pump operates in the preheating circulating mode; calculating a return water and outlet water temperature difference limit value according to the minimum input load of the equipment and the average circulating water flow, wherein the return water and outlet water temperature difference limit value is the difference between an outlet water temperature threshold value and a return water temperature threshold value; acquiring a backwater temperature threshold according to the backwater and water outlet temperature difference limit value and a preset water outlet temperature threshold; and monitoring the backwater temperature and the water outlet temperature, and stopping combustion when the backwater temperature is greater than or equal to a backwater temperature threshold value or the water outlet temperature is greater than or equal to a preset water outlet temperature threshold value.

In some embodiments, the step of obtaining the return water temperature threshold comprises: calculating a backwater temperature threshold according to the backwater and water outlet temperature difference limit value and a preset water outlet temperature threshold; when the calculated backwater temperature threshold value is smaller than a preset minimum allowable backwater temperature threshold value, setting the preset minimum allowable backwater temperature threshold value as a backwater temperature threshold value; otherwise, maintaining the calculated backwater temperature threshold value.

In some embodiments, the preheating circulation control method further comprises stopping the operation of the circulating water pump after the circulating water pump continues to operate for a predetermined period of time when the backwater temperature is greater than or equal to the backwater temperature threshold or the effluent temperature is greater than or equal to the effluent temperature threshold.

In some embodiments, the predetermined outlet water temperature threshold is predetermined according to a warm-up cycle set temperature.

A second aspect of the disclosed embodiments provides a computer-readable storage medium having stored thereon instructions which, when executed by a processor, perform the above-described method steps.

A third aspect of the disclosed embodiments provides a gas water heating apparatus comprising a burner assembly, a flow sensor, a return water temperature sensor, a outlet water temperature sensor, a circulating water pump, and a controller. Wherein the controller is configured to: acquiring average circulating water flow when the circulating water pump operates in a preheating circulating mode through a flow sensor; calculating a return water and outlet water temperature difference limit value according to the minimum input load of the equipment and the average circulating water flow, wherein the return water and outlet water temperature difference limit value is the difference between an outlet water temperature threshold value and a return water temperature threshold value; acquiring a backwater temperature threshold according to the backwater and water outlet temperature difference limit value and a preset water outlet temperature threshold; the backwater temperature and the water outlet temperature are respectively monitored by a backwater temperature sensor and a water outlet temperature sensor; and stopping the burner assembly when the backwater temperature is greater than or equal to a backwater temperature threshold value or the effluent temperature is greater than or equal to a preset effluent temperature threshold value.

In some embodiments, the controller obtaining control of the backwater temperature threshold includes: calculating a backwater temperature threshold according to the backwater and water outlet temperature difference limit value and a preset water outlet temperature threshold; when the calculated backwater temperature threshold value is smaller than a preset minimum allowable backwater temperature threshold value, setting the preset minimum allowable backwater temperature threshold value as a backwater temperature threshold value; otherwise, maintaining the calculated backwater temperature threshold value.

In some embodiments, the controller is further configured to control the circulating water pump to stop operating after continuing to operate for a predetermined period of time when the return water temperature is greater than or equal to the return water temperature threshold, or the outlet water temperature is greater than or equal to the outlet water temperature threshold.

In some embodiments, the predetermined outlet water temperature threshold is predetermined based on a pre-heat cycle set temperature.

The technical solution provided by one or more embodiments of the present disclosure may include the following beneficial effects: according to the circulating water flow self-adaptive regulation backwater temperature threshold value, the frequent start and stop of the equipment in the preheating process can be relieved, and meanwhile, the preheating in the circulating pipeline is more sufficient and the temperature distribution is more uniform. In addition, the minimum allowable backwater temperature threshold value is preset to avoid the condition that the circulation water temperature is too low to influence the comfort level of a user due to the fact that the adjusted backwater temperature threshold value is too low.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort to a person of ordinary skill in the art.

FIG. 1 is a schematic block diagram of a gas water heating apparatus connected to a water heating system in an embodiment of the present disclosure;

FIG. 2 is a schematic block diagram of a gas water heating apparatus connected to a water heating system in accordance with another embodiment of the present disclosure;

FIG. 3 is a flow chart of a method of controlling a circulating water pump of the gas water heating apparatus when operating in a warm-up circulation mode in one embodiment;

FIG. 4 is a flow chart of a control method for stopping a warm-up cycle of a gas water heating apparatus in one embodiment;

FIG. 5 is a flow chart of a control method of the gas water heater apparatus for preheating cycle control in another embodiment;

FIG. 6 is a flowchart of an alternative embodiment of FIG. 5, which discloses another control method of the gas water heater apparatus for preheating cycle control.

Detailed Description

The embodiments shown in the drawings will be described in detail below. These embodiments do not represent all embodiments consistent with the present disclosure, and structural, methodological, or functional transformations of one of ordinary skill in the art based on these embodiments are included within the scope of the appended claims.

The gas water heating device is a gas water heater which uses combustible gas as fuel, such as natural gas, city gas, liquefied gas, biogas and the like, and provides heat by combusting the combustible gas to meet the living demands of users, for example, a gas water heater which provides living hot water, a gas boiler which can simultaneously provide living hot water and heating demands, and the like.

The hot water system 100 according to one embodiment of the present disclosure as shown in fig. 1, wherein the gas water heating apparatus is a gas water heater, which is in communication with a water point (such as a mixing valve tap) 70 through a cold water pipe 51 and a hot water pipe 52; further, a return pipe 53 is connected between the gas water heating apparatus and the hot water pipe 52. The pipeline can be a water flow passage formed by connecting a plurality of water pipes. The water consumption points can be multiple and are respectively connected with the cold water pipeline and the hot water pipeline. In this embodiment, the water usage point 70 is one water usage point farthest or farther from the gas water heating apparatus among the plurality of water usage points. When the gas water heating apparatus is operated in the bathroom mode, i.e., domestic hot water is supplied, cold water and hot water are supplied to the water point 70 via the cold water pipe 51 and the hot water pipe 52, respectively, and are mixed and then outputted. When the gas water heating device works in the preheating circulation mode, hot water output by the device flows back to the device through the hot water pipeline 52 and the water return pipe 53 to be reheated. In some embodiments, a check valve 54 is also provided on the return pipe 53 to limit the flow of water from the hot water line 52 to the gas water heater only in one direction via the return pipe 53.

The gas water heating apparatus includes a housing 10, a burner assembly, a heat exchanger 13, a smoke exhaust device, and the like, which are housed in the housing 10. The housing 10 may be formed from a plurality of panels that are joined together to form a receiving space therein for receiving the components. A water inlet pipe 111 is arranged in the shell 10, and a water outlet pipe 112 and a fuel gas supply pipeline 113 extend out of the bottom of the shell 10. Wherein the water inlet pipe 111 is connected to the cold water pipe 51 through the first pipe section 1111 and to the return water pipe 53 through the second pipe section 1112, and the water outlet pipe 112 is directly connected to the hot water pipe 52.

The burner assembly generally includes a gas distribution frame (not shown) and a burner 12. An air valve 15 is provided on the gas supply line 113, and the air valve 15 may be an electrically controllable valve for connecting or disconnecting the gas supply passage and controlling the amount of gas supplied into the gas distribution frame. In some embodiments, the combustor 12 includes several combustion units arranged side-by-side in the longitudinal direction. Each combustion unit has a flat plate shape, which is generally vertically fixed in a burner frame, has an air inlet provided at a lower portion thereof, has a plurality of fire holes provided at a top portion thereof, and a gas-air mixing passage communicating the air inlet and the plurality of fire holes. The gas passing through the gas valve 15 enters the gas inlet of each combustion unit through the distribution of the gas separation frame and is mixed with the primary air simultaneously entering in the gas-air mixing channel and transferred to the fire holes at the top of the fire grate for combustion and generation of hot flue gas. The burner assembly further comprises ignition means 121 for igniting the gas and air mixture, and flame detection means 122 for detecting the presence or absence of a flame. In some embodiments, the ignition device 121 includes a pair of ignition electrodes extending above the fire holes of the combustion unit. The flame detection means 122 comprises a flame detection electrode extending over the fire hole of the combustion unit.

The heat generated by the combustion of the burner 12 passes through a heat exchanger 13. The heat exchanger 13 is typically disposed above the burner 12. In some embodiments, the heat exchanger may be a fin-and-tube heat exchanger, i.e., a heat exchanger housing having a plurality of fins disposed therein through which a heat exchange water pipe passes in a detour, both ends of which are respectively in communication with an inlet pipe 111 located upstream in the water flow direction and an outlet pipe 112 located downstream in the water flow direction. The heat generated by the combustion of the gas-air mixture is absorbed by the fins and further transferred to the water flowing through the heat exchange water pipe, and the heated water is transferred to the hot water pipe 52 through the water outlet pipe 112, thereby providing domestic hot water for drinking, bathing, etc. to the user.

In some embodiments, a fan 16 may be provided below the burner 12 to drive the flow of air to provide the air required for combustion and to cause the smoke produced by the combustion to be collected by the fume collection hood of the fume extractor and to be exhausted through a fume exhaust line (not shown) connected to the fume collection hood. A water inlet temperature sensor 171 is provided at the inlet pipe 111 (e.g., on the outer wall of the inlet pipe) for sensing the temperature of the water flow through the inlet pipe. In the warm-up circulation mode, the water intake temperature sensor 171 is used to detect the temperature of the return water flowing into the water intake pipe 111 through the return water pipe 54 and the second pipe section 1112, and is therefore used as a return water temperature sensor at this time; while in the bathroom mode, the temperature sensor 171 is used to detect the temperature of the cold water flowing into the inlet pipe 111 through the first pipe section 1111. A water outlet temperature sensor 172 is disposed at the outlet pipe 112 (e.g., on the outer wall of the outlet pipe) for detecting the temperature of the water outlet passing through the outlet pipe. The temperature sensor may be a thermistor, such as a positive temperature coefficient thermistor (Positive Temperature Coefficient, PTC), and in some embodiments, the temperature sensor may also be a negative temperature coefficient (Negative Temperature Coefficient, NTC) temperature sensor. A flow sensor 14 is provided in the waterway for sensing the flow of water. In some embodiments, the flow sensor may be installed at the first pipe section 1111 for detecting a cold water inflow rate flowing in via the cold water line 51. The flow sensor 14 may include a rotor assembly with magnets and a hall element that is rotated when water is flowing through the sensing device, thereby utilizing the hall effect of the hall element to measure a magnetic physical quantity. A circulating water pump 18 is provided in the waterway for driving or promoting water flow. In the present embodiment, the circulating water pump 18 is connected to the water inlet pipe 111, and in other embodiments, the circulating water pump 18 may be connected to the second pipe section 1112.

A controller 20 is provided within the housing 10 for detecting and controlling the operation of the various components and circuit devices within the gas water heating apparatus. In some embodiments, the controller 20 may be a control circuit including a processor and a memory, and a plurality of electronic components connected in a wired manner. The processor may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. The general purpose processor may be a microprocessor or any conventional processor. In this embodiment, the processor is a control center of the gas water heating apparatus that connects the various parts of the apparatus using various interfaces and lines. For example, the controller 20 is electrically connected to or in wireless communication with the air valve 15, the fan 16, the return water temperature sensor 171, the outlet water temperature sensor 172, the flow sensor 14, the circulating water pump 18, and the like.

The memory may be used to store instructions of any application or method operating on the processor of the controller, as well as various types of data. The processor implements various functions of the gas water heating apparatus by running or executing programs or instructions stored in the memory and invoking data stored in the memory. The memory may comprise any type or combination of volatile or nonvolatile memory devices such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), magnetic memory, flash memory, solid state memory, magnetic or optical disk, and the like.

Fig. 2 shows a further embodiment of a hot water system 200, which is similar to the heating system 100 shown in fig. 1, with the main difference that the return pipe 63 is connected between the cold water pipe 51 and the hot water pipe 52 near the water point 70 by means of two three-

way connections

61, 62. By the mode, even if a user does not lay the water return pipe in advance in the house decoration, the water return pipe can be connected between the cold water pipe and the hot water pipe at the water consumption point (such as the lower part of the basin) at the far end of the gas water heating equipment to realize the preheating circulation function. Similarly, the return pipe 63 is further provided with a check valve 64 to limit the flow of water from the hot water line 52 to the cold water line 51 via the return pipe 63 and further back to the gas water heating apparatus via the inlet pipe 111. Further, in the present embodiment, the water intake pipe 111 is directly connected to the cold water pipe 51, and the flow sensor 14 is provided on the water intake pipe 111.

Fig. 3 shows steps of a method for controlling a circulating water pump of the gas water heating apparatus in the warm-up circulation mode according to an embodiment, and the steps of the method are described in detail below with reference to the controller 20.

Step 301: the preheat cycle mode is triggered.

In some embodiments, the warm-up cycle mode may be active for a fixed period of time, such as between 4 and 6 pm. The start time of the fixed period of time may be arbitrarily set by the user through the control panel of the device or a cell phone application associated therewith. In other embodiments, the preheat cycle mode may be active at all times, or may be turned on and off at any time by a separate function key.

Step 302: and acquiring a temperature difference limit value delta T of the backwater and the effluent.

The temperature difference limit Δt between the backwater and the water outlet is the difference between the water outlet temperature threshold Tol and the backwater temperature threshold Til, i.e., Δt=tol-Til. In some embodiments, Δt is preset and stored in the storage medium. In other embodiments, the outlet water temperature threshold value Tol and the return water temperature threshold value Til are preset and stored in the storage medium, and then the return water and outlet water temperature difference limit Δt is calculated by the difference Tol-Til between the outlet water temperature threshold value and the return water temperature threshold value. In other embodiments, the outlet water temperature threshold Tol and the return water temperature threshold Til may also be predetermined based on the warm-up cycle set temperature Ts. For example, a warm-up cycle set temperature Ts is first obtained, which may be set by a user, that is, a temperature to which the user wishes to warm up the circulating water in the circulation system; of course, if the cycle temperature Ts set by the user is too high or too low, such as exceeding an upper limit value of 43 ℃ or falling below a lower limit value of 37 ℃, the upper limit value or the lower limit value is set as the warm-up cycle temperature Ts. Then, the water outlet temperature threshold Tol and the water return temperature threshold Til are determined according to the warm-up cycle set temperature Ts. Wherein, the water outlet temperature threshold Tol is a temperature difference T1 superimposed on the preheating cycle set temperature Ts, i.e. tol=ts+t1, such as t1=6deg.C; the return water temperature threshold Til is a temperature difference T2 subtracted from the preheating cycle set temperature Ts, i.e., til =ts-T2, such as t2=5 ℃. And then, calculating the temperature difference limit delta T of the backwater and the water outlet through the difference Tol-Til between the water outlet temperature threshold and the backwater temperature threshold.

Step 303: and calculating the target circulating water flow Qt.

And calculating the target circulating water flow Qt according to the minimum input load Pmin of the equipment and the temperature difference limit value delta T of backwater and outlet water. For example, the target circulating water flow rate Qt may be calculated according to the formula qt=pmin/(c×Δt), where c is the specific heat capacity of water.

Step 304: starting the circulating water pump to obtain the current water flow Qc.

During operation of the circulating water pump 18 in the warm-up circulation mode, the controller 20 may acquire the current water flow Qc in real time through the flow sensor 14. In some embodiments, the controller 20 may also acquire current water flow data via the flow sensor 14 at regular intervals, such as 0.1 seconds.

Step 305: comparing the current water flow Qc with the target circulating water flow Qt, and if the current water flow Qc is greater than or equal to the target circulating water flow Qt, executing step 310; if the current water flow Qc is less than the target circulating water flow Qt, step 306 is performed.

Step 306: the rotational speed of the water pump is increased.

If the current water flow Qc is less than the target circulating water flow Qt, the rotational speed of the circulating water pump 18 is continuously increased until the current water flow Qc is greater than or equal to the target circulating water flow Qt. In some embodiments, the current water flow Qc and the target circulating water flow Qt may be used as inputs to regulate the rotational speed of the circulating water pump 18 using a PID (proportional-Integral-derivative) control module.

Step 307: and judging whether the water flow Qmax of the water pump running at the maximum rotating speed is still smaller than the target circulating water flow Qt.

As the rotational speed of the circulating water pump 18 increases, if the water flow Qmax at which the water pump is running at the maximum rotational speed has not yet reached the target circulating water flow Qt, then step 308 is performed; otherwise, if the current water flow rate can reach the target circulating water flow rate Qt during the increase of the rotation speed of the water pump, step 309 is executed.

Step 308: the controller 20 keeps the circulating water pump 18 running at a maximum rotational speed.

Step 309: the controller 20 keeps the circulating water pump 18 running at a corresponding rotational speed when the target circulating water flow Qt is reached.

Step 310: the controller 20 keeps the circulating water pump 18 running at the current rotating speed;

step 311: and (5) igniting and burning.

After the rotation speed of the circulating water pump 18 is stable, the controller 20 controls the air valve 15 to be opened to a proper opening degree, controls the fan 16 to run at a certain rotation speed, and controls the burner assembly to ignite and burn.

By ensuring larger circulating water flow during preheating circulation, the device is prevented from being frequently started and stopped due to too fast local temperature rise in the preheating circulation pipeline, and meanwhile, the preheating in the circulation pipeline is more sufficient and the temperature distribution is more uniform.

Fig. 4 shows steps of a control method for stopping the warm-up cycle of the gas water heating apparatus according to an embodiment, and the steps of the control method are described in detail below.

During the operation of the preheating circulation mode (step 401), the controller 20 monitors the backwater temperature and the outlet water temperature through the backwater temperature sensor 171 and the outlet water temperature sensor 172, respectively, and judges whether the collected backwater temperature Ti is greater than or equal To a backwater temperature threshold Til or whether the outlet water temperature To is greater than or equal To an outlet water temperature threshold Tol (step 402); if so, the burner assembly is controlled to stop operating (step 403), and the circulating water pump 18 is controlled to stop operating after a predetermined period of time has elapsed (step 404), so that the water temperature distribution in the circulating line is more uniform.

Fig. 5 shows steps of a control method for controlling the warm-up cycle of the gas water heating apparatus according to an embodiment, and the steps of the method are described in detail below with respect to the execution of the steps by the controller 20.

Step 801: the preheat cycle mode is triggered.

Step 802: the circulating water pump is started to obtain the average circulating water flow Qav.

During operation of the recirculation pump 18 in the warm-up circulation mode, the controller 20 may obtain an average recirculation flow Qav via the flow sensor 14. In some embodiments, the controller 20 may also acquire and store current water flow data via the flow sensor 14 at regular intervals, i.e., sampling periods, such as 0.1 seconds; in the process of stable operation of the water pump, an average value is calculated according to a plurality of flow values acquired in a plurality of (e.g. 10) continuous sampling periods, and then the average circulating water flow Qav is obtained.

Step 803: and calculating a temperature difference limit value delta T of the backwater and the effluent.

The temperature difference limit Δt between the backwater and the water outlet is the difference between the water outlet temperature threshold Tol and the backwater temperature threshold Til, i.e., Δt=tol-Til, which can be calculated by the minimum input load Pmin of the apparatus and the average circulating water flow Qav. For example, the temperature difference between the backwater and the effluent is calculated according to the formula Δt=pmin/(c× Qav), where c is the specific heat capacity of water.

Step 804: a backwater temperature threshold Til is obtained.

In some embodiments, the backwater temperature threshold Til may be calculated from the backwater and effluent temperature difference limit Δt and the predetermined effluent temperature threshold Tol, i.e., til =tol- Δt. The water outlet temperature threshold Tol may be preset and stored in the storage medium. In other embodiments, the water outlet temperature threshold Tol may also be predetermined based on the warm-up cycle set temperature Ts. For example, a preheating circulation set temperature Ts is first obtained, which may be set by a user, that is, a temperature to which the user wants to preheat the circulating water in the circulation line; of course, if the cycle temperature Ts set by the user is too high or too low, such as exceeding an upper limit value of 43 ℃ or falling below a lower limit value of 37 ℃, the upper limit value or the lower limit value is set as the warm-up cycle temperature Ts. Then, a water outlet temperature threshold Tol is determined according to the preheating cycle set temperature Ts, and a temperature difference T1 is superimposed on the preheating cycle set temperature Ts, i.e. tol=ts+t1, such as t1=6 ℃.

Step 805: and (5) igniting and burning.

The controller 20 controls the air valve 15 to be opened to a proper opening degree, controls the fan 16 to operate at a certain rotating speed and controls the burner assembly to ignite and burn.

Step 806: and judging whether a preheating cycle stopping condition is reached.

In the warm-up cycle mode, the controller 20 monitors the backwater temperature and the outlet water temperature through the backwater temperature sensor 171 and the outlet water temperature sensor 172, respectively, and judges whether the collected backwater temperature Ti is greater than or equal To a backwater temperature threshold Til or whether the outlet water temperature To is greater than or equal To an outlet water temperature threshold Tol; if so, step 807 is performed.

Step 807: the combustion is stopped, i.e., the controller 20 controls the burner assembly to stop operating, and closes the air valve 15 and stops the fan 16 from operating.

Step 808: the controller 20 further controls the circulating water pump 18 to stop operating after continuing to operate for a predetermined period of time so that the water temperature distribution in the circulating line is more uniform.

Fig. 6 shows steps of a control method for controlling a warm-up cycle of a gas water heating apparatus according to another embodiment, and the steps of the method are described in detail below with reference to the controller 20.

Step 811: the preheat cycle mode is triggered.

Step 812: the circulating water pump is started to obtain the average circulating water flow Qav.

Step 813: and calculating a temperature difference limit value delta T of the backwater and the effluent.

Step 814: a backwater temperature threshold Til is calculated.

Step 815: it is determined whether the calculated backwater temperature threshold Til is greater than or equal to a predetermined minimum allowable backwater temperature threshold Talo. If yes, maintaining the calculated backwater temperature threshold value, and executing step 817; if the calculated backwater temperature threshold Til is less than the predetermined minimum allowable backwater temperature threshold Talo, step 816 is performed.

Step 816: when the calculated backwater temperature threshold Til is smaller than the predetermined minimum allowable backwater temperature threshold Talo, the predetermined minimum allowable backwater temperature threshold Talo is set as the backwater temperature threshold Til, and step 817 is performed. The minimum allowable backwater temperature threshold Talo is preset to avoid that the calculated backwater temperature threshold Til is too low to influence the comfort of the user.

Step 817: and (5) igniting and burning.

Step 818: and judging whether a preheating cycle stopping condition is reached.

Step 819: the combustion is stopped, i.e., the controller 20 controls the burner assembly to stop operating, and closes the air valve 15 and stops the fan 16 from operating.

Step 820: the controller 20 further controls the circulating water pump 18 to stop operating after continuing to operate for a predetermined period of time so that the water temperature distribution in the circulating line is more uniform.

After the circulating waterway in the user's home is used for a long time, the circulating water flow is possibly reduced due to the increase of the water resistance, and the backwater temperature threshold value is adaptively adjusted according to the circulating water flow in the embodiment, so that the frequent start and stop of the equipment in the preheating process can be relieved, and meanwhile, the preheating in the circulating waterway is more sufficient and the temperature distribution is more uniform. In addition, the minimum allowable backwater temperature threshold value is preset to avoid the condition that the circulation water temperature is too low to influence the comfort level of a user due to the fact that the adjusted backwater temperature threshold value is too low.

All or part of the steps in the methods of the above disclosed embodiments may be accomplished by computer programs to instruct related hardware. The computer program may be stored in a computer readable storage medium, which computer program, when being executed by a processor, implements the steps of the various method embodiments described above. Wherein the computer program comprises computer program code, which may be in source code form, object code form, executable file or some intermediate form, etc. The readable storage medium may comprise any type or combination of volatile or non-volatile memory devices, such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), magnetic memory, flash memory, solid state memory, magnetic or optical disk, and the like.

It should be understood that the methods and apparatus disclosed in the foregoing disclosure may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, such as the division of units in a controller is merely a division of one logic function, and there may be additional divisions in actual implementation, e.g., multiple units may be combined or integrated into another system, or some features may be omitted, or not performed. In addition, the components, elements, units discussed above may be electrically, mechanically, or otherwise connected to each other; may be a direct connection or an indirect connection via some interfaces or the like; either a wired connection or a wireless communication.

Further, the units described above as separate members may or may not be physically separate, and members shown as units may or may not be physical units; some or all of the elements may be selected according to actual needs to achieve the objectives of the disclosed embodiment. In addition, each functional unit in each embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in hardware plus software functional units.

It should be understood that although the present disclosure describes embodiments in terms of examples, not every embodiment is provided with a single embodiment, and that this description is for clarity only, and that the embodiments of the disclosure may be combined appropriately to form other embodiments that will be understood by those skilled in the art.

Claims

1. A method for controlling a preheating cycle of a gas water heating apparatus, the method comprising:

obtaining the average circulating water flow when the circulating water pump operates in the preheating circulating mode;

calculating a temperature difference limit value between backwater and outlet water according to the minimum input load of the equipment and the average circulating water flow, wherein the temperature difference limit value between backwater and outlet water is the difference between a water outlet temperature threshold value and a backwater temperature threshold value;

acquiring a backwater temperature threshold according to the backwater and water outlet temperature difference limit value and a preset water outlet temperature threshold;

and monitoring the backwater temperature and the water outlet temperature, and stopping combustion when the backwater temperature is greater than or equal to the backwater temperature threshold value or the water outlet temperature is greater than or equal to the preset water outlet temperature threshold value.

2. The warm-up cycle control method of a gas water heating apparatus according to claim 1, characterized in that: the step of acquiring the backwater temperature threshold value comprises the following steps of,

calculating a backwater temperature threshold according to the backwater and water outlet temperature difference limit value and a preset water outlet temperature threshold;

when the calculated backwater temperature threshold value is smaller than a preset minimum allowable backwater temperature threshold value, setting the preset minimum allowable backwater temperature threshold value as a backwater temperature threshold value; otherwise, maintaining the calculated backwater temperature threshold value.

3. The warm-up cycle control method of a gas water heating apparatus according to claim 1, characterized in that: the method further comprises stopping the circulating water pump after the circulating water pump continues to operate for a preset time when the backwater temperature is greater than or equal to a backwater temperature threshold value or the effluent temperature is greater than or equal to an effluent temperature threshold value.

4. The warm-up cycle control method of a gas water heating apparatus according to claim 1, characterized in that: the preset water outlet temperature threshold value is preset according to the preheating cycle set temperature.

5. A computer-readable storage medium having instructions stored thereon, characterized by: the instructions, when executed by a processor, implement the method of any of claims 1-4.

6. A gas water heating apparatus, characterized in that: the device comprises a burner assembly, a flow sensor, a backwater temperature sensor, a water outlet temperature sensor, a circulating water pump and a controller; wherein the controller is configured to

Acquiring average circulating water flow when the circulating water pump operates in a preheating circulating mode through a flow sensor;

the backwater temperature and the water outlet temperature are respectively monitored by a backwater temperature sensor and a water outlet temperature sensor;

and stopping the burner assembly when the backwater temperature is greater than or equal to the backwater temperature threshold value or the effluent temperature is greater than or equal to the preset effluent temperature threshold value.

7. Gas water heating apparatus according to claim 6, characterized in that: the controller obtaining control of the backwater temperature threshold value comprises,

8. Gas water heating apparatus according to claim 6, characterized in that: the controller is also configured to control the circulating water pump to stop working after the circulating water pump continues to operate for a preset time period when the backwater temperature is greater than or equal to a backwater temperature threshold value or the effluent temperature is greater than or equal to an effluent temperature threshold value.

9. Gas water heating apparatus according to claim 6, characterized in that: the preset water outlet temperature threshold value is preset according to the preheating cycle set temperature.