Water system air conditioner and water system air conditioner filter cleaning control method

Abstract

The application provides a water system air conditioner and a filter screen cleaning control method of the water system air conditioner, and relates to the technical field of air conditioners, and aims to solve the problem of low filter cleaning efficiency in a water circulation loop. The water system air conditioner comprises a water circulation loop and a filter screen cleaning device, the water circulation loop comprises a water pump, a heat exchanger and a filter which are sequentially connected, and the filter screen cleaning device is connected with the filter. The water system air conditioner provided by the application can improve the cleaning efficiency of the filter.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more specifically, to a water system air conditioner and a method for controlling the cleaning of the filter screen of a water system air conditioner. Background Technology

[0002] In water-cooled air conditioning systems, filters are typically installed in the water pipes to remove impurities from the water flow. After prolonged use, these filters are prone to clogging, causing poor water flow and affecting heat exchange efficiency. Currently, the problem of clogged filters is usually solved by manual cleaning by users or maintenance personnel. However, manual cleaning is not only complex and creates a poor working environment, but it is also prone to delays, making it impossible to guarantee the efficient operation of the water-cooled air conditioning system. Summary of the Invention

[0003] The first objective of this invention is to provide a water system air conditioner to solve the technical problem of low filter cleaning efficiency in existing water circulation loops.

[0004] The water system air conditioner provided by the present invention includes a water circulation loop and a filter cleaning device. The water circulation loop includes a water pump, a heat exchanger and a filter connected in sequence, and the filter cleaning device is connected to the filter.

[0005] The beneficial effects of the water system air conditioner of this invention are:

[0006] By installing a filter cleaning device, the filter screen can be automatically cleaned when it becomes clogged, affecting the flow resistance of the water circulation loop and reducing the water flow. This removes the blockages from the filter screen, reducing the flow resistance of the water circulation loop to a normal level and keeping the water circulation loop unobstructed.

[0007] In a preferred embodiment, the water circulation loop includes a first shut-off valve, which is located between the first liquid outlet of the filter and the water pump.

[0008] By installing a first shut-off valve between the first liquid outlet of the filter and the water pump, the water circulation loop between the first liquid outlet and the water pump can be cut off by the shut-off valve, so that after the rinsing water is used to rinse the filter screen, it will not be discharged from the normally output first liquid outlet and will not continue to enter the water pump.

[0009] In a preferred embodiment, the filter cleaning device includes a decontamination pump and a second shut-off valve. The outlet of the decontamination pump is connected to the liquid inlet of the filter, and the second shut-off valve is connected to the second liquid outlet of the filter.

[0010] By installing a sludge pump, external fluid can be directly introduced into the water circulation loop to flush the filter. This minimizes fluid energy loss and facilitates a more thorough cleaning of the filter screen. The second shut-off valve controls the opening and closing of the filter's second liquid outlet. When the second shut-off valve is closed, the second liquid outlet is blocked, preventing water entering the filter from exiting. When the second shut-off valve is open, the second liquid outlet is open, allowing water to exit. Therefore, when cleaning the filter using the filter screen cleaning device, the sludge pump can be turned on to inject water into the filter, and the second shut-off valve can be opened while the first shut-off valve is closed. This ensures that the flushing water flows only from the second liquid outlet and not from the first liquid outlet, effectively removing water mixed with dirt and blockages.

[0011] In a preferred embodiment, the filter cleaning device further includes a cleaning water tank, the inlet of the dirt removal pump is connected to the cleaning water tank, and the outlet of the second shut-off valve is connected to the cleaning water tank.

[0012] By setting up a cleaning water tank connected to the inlet of the sludge pump and the outlet of the second shut-off valve, water can be directly drawn from the cleaning water tank by the sludge pump to rinse the filter. Since the sewage containing dirt and blockages discharged after rinsing the filter can settle, and the rinsing interval is sufficient to achieve relatively complete sedimentation, there is no need to re-pump water for rinsing each time, thus saving water resources.

[0013] In a preferred embodiment, the filter cleaning device further includes a third shut-off valve, which is located between the outlet of the sewage pump and the water circulation loop.

[0014] By installing a third shut-off valve, the connection between the sludge pump and the water circulation loop can be controlled independently. Isolating the sludge pump from the water circulation loop will not affect the normal operation of the water circulation loop. When filter cleaning is not required, both the second and third shut-off valves can be closed to isolate the water circulation loop from the filter cleaning device, ensuring the normal operation of the water circulation loop.

[0015] In a preferred embodiment, the water circulation loop further includes a fourth shut-off valve located between the heat exchanger and the connection point of the third shut-off valve and the water circulation loop.

[0016] By installing a fourth shut-off valve in the water circulation loop, when the filter cleaning device cleans the filter screen, the fourth shut-off valve is closed in conjunction with the closure of the first shut-off valve, thus isolating the rest of the water circulation loop from the area involved in the cleaning and preventing it from being affected by the cleaning fluid.

[0017] In the preferred embodiment, the water pump is a variable frequency water pump.

[0018] By setting up a variable frequency water pump, the pump's duty cycle can be obtained. This allows us to determine the water's operating status in the water circulation loop based on the pump's drive signal duty cycle, thus determining whether the filter needs cleaning.

[0019] The second objective of this invention is to provide a method for controlling the cleaning of filters in a water system air conditioner, in order to solve the technical problem of low cleaning efficiency of filters in the water circulation loop.

[0020] The water system air conditioner filter cleaning control method provided by the present invention is applied to the above-mentioned water system air conditioner, and the water system air conditioner filter cleaning control method includes:

[0021] Obtain the feedback duty cycle of the water pump and the absolute value of the temperature difference of the water circulation loop through the heat exchanger;

[0022] Based on the comparison between the feedback duty cycle and the first preset duty cycle, and the comparison between the absolute value of the temperature difference and the first preset temperature difference value, the filter cleaning device is controlled to clean the filter.

[0023] The beneficial effects of the water system air conditioner of this invention are:

[0024] By obtaining the feedback duty cycle and comparing it with a first preset duty cycle, when the filter becomes clogged, the resistance to water circulation increases, the water flow rate decreases, and the corresponding feedback duty cycle decreases. When the water pump's feedback duty cycle falls below a certain set value, such as below the first preset duty cycle, it indicates severe filter clogging, requiring the activation of the automatic cleaning device. Furthermore, the reduced flow rate in the water circulation loop increases the temperature difference between the two ends of the heat exchanger. When the temperature difference exceeds the first preset temperature difference value, it also indicates severe clogging, necessitating cleaning. Therefore, this solution eliminates the need for direct inspection and observation of the filter screen surface; automatic filter cleaning can be achieved by monitoring other parameters.

[0025] In a preferred embodiment, controlling the filter cleaning device to clean the filter includes:

[0026] The system controls the first shut-off valve to open, the water pump to shut down, the sewage pump to start, and the second shut-off valve to open.

[0027] By controlling the first shut-off valve to disconnect, the water pump is shut off, and the sludge pump is started to open the second shut-off valve. Water can be pumped by the sludge pump to flush the filter, and the dirty water from flushing the filter screen will not flow into the water pump, thus preventing damage to the water pump.

[0028] In a preferred embodiment, controlling the filter cleaning device to clean the filter further includes:

[0029] If the cleaning time of the filter reaches the preset duration, the first shut-off valve is opened, which can control the water pump to start, control the descaling pump to shut down, and control the second shut-off valve to disconnect.

[0030] Obtain the feedback duty cycle of the water pump;

[0031] Based on the comparison between the feedback duty cycle and the second preset duty cycle, the filter cleaning device is controlled to continue cleaning the filter.

[0032] After automatic flushing for a period of time, the water circulation loop is restarted. Based on the comparison between the feedback duty cycle and the second preset duty cycle, the system automatically controls whether to continue cleaning the filter. This not only ensures that the filter is cleaned sufficiently to guarantee the smooth flow of the water circulation loop, but also saves cleaning time, reduces downtime of the water circulation loop, and improves the normal utilization rate of the equipment.

[0033] In a preferred embodiment, controlling the first shut-off valve to open can control the water pump to start, control the sewage pump to shut down, and control the second shut-off valve to open.

[0034] Obtain the feedback duty cycle of the water pump and the absolute value of the temperature difference of the water circulation loop through the heat exchanger;

[0035] Based on the comparison between the feedback duty cycle and the second preset duty cycle, and the comparison between the absolute value of the temperature difference and the second preset temperature difference value, the filter cleaning device is controlled to continue cleaning the filter.

[0036] After the cleaning time reaches the preset time, the water circulation loop is restarted for testing. In addition to obtaining the feedback duty cycle, the absolute value of the temperature difference passing through the heat exchanger is also obtained, so as to obtain the operating status of the water circulation loop more accurately and to grasp the clogging status of the filter. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments or background art of the present invention, the drawings used in the description of the embodiments or background art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of a water system air conditioner provided in Embodiment 1 of the present invention;

[0039] Figure 2 This is a schematic diagram of another implementation of the water system air conditioner provided in Embodiment 1 of the present invention;

[0040] Figure 3 This is a flowchart illustrating the water system air conditioner filter cleaning control method provided in Embodiment 2 of the present invention.

[0041] Explanation of reference numerals in the attached figures:

[0042] 11-Water pump; 12-Heat exchanger; 13-Filter; 14-First shut-off valve; 15-Fourth shut-off valve; 16-Panel heat exchanger outlet temperature sensor; 17-Panel heat exchanger inlet temperature sensor;

[0043] 21-Sewage pump; 22-Second shut-off valve; 23-Third shut-off valve; 24-Cleaning water tank; 25-Electric three-way valve;

[0044] 31-Finned heat exchanger; 32-Electronic expansion valve; 33-Compressor. Detailed Implementation

[0045] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0046] Example 1:

[0047] Figure 1 This is a schematic diagram of the structure of a water system air conditioner provided in Embodiment 1 of the present invention. Figure 1 As shown, the water system air conditioner provided in Embodiment 1 of the present invention includes a water circulation loop and a filter cleaning device. The water circulation loop includes a water pump 11, a heat exchanger 12 and a filter 13 connected in sequence. The filter cleaning device is connected to the filter 13.

[0048] In this embodiment, the heat exchanger 12 can be a plate heat exchanger. At the inlet and outlet of the plate heat exchanger, a plate heat exchanger inlet temperature sensor 17 and a plate heat exchanger outlet temperature sensor 16 are respectively provided.

[0049] By setting up a filter cleaning device, when the filter 13 becomes clogged, affecting the flow resistance of the water circulation loop and reducing the water flow, the filter screen can be automatically cleaned to remove the blockages, thereby reducing the flow resistance of the water circulation loop to a normal level and keeping the water circulation loop unobstructed.

[0050] like Figure 1 As shown, preferably, the water circulation loop includes a first shut-off valve 14, which is located between the first liquid outlet of the filter 13 and the water pump 11.

[0051] The filter 13 has a liquid inlet and two liquid outlets—a first liquid outlet and a second liquid outlet. The filter screen of the filter 13 is located between the liquid inlet and the first liquid outlet. When water flows through the filter screen, at least some of the dirt in the water flow is left on the filter screen, while the remaining relatively clean water passes through the filter screen and flows to the water pump 11 through the first liquid outlet. Moreover, the second liquid outlet of the filter 13 is offset from the water circulation loop. When the cleaning water flows to rinse the filter screen, it can wash away the blockages attached to the filter screen and discharge them from the second liquid outlet along with the rinsing water.

[0052] By setting a first shut-off valve 14 between the first liquid outlet of the filter 13 and the water pump 11, the water circulation loop between the first liquid outlet and the water pump 11 can be cut off by the shut-off valve, so that after the rinsing water rinses the filter screen, it will not be discharged from the normally output first liquid outlet and will not continue to enter the water pump 11.

[0053] In addition to the implementation method described later, for example, water pump 11 can be used to output water to clean the filter screen of filter 13. In this case, the first shut-off valve 14 is closed, and the flushed water is discharged from the second liquid outlet. Of course, with this implementation method, the water output from water pump 11 flows through a longer path, resulting in greater fluid pressure loss, and it is not as good as the implementation method described later.

[0054] like Figure 1 As shown, preferably, the filter cleaning device includes a dirt removal pump 21 and a second shut-off valve 22. The outlet of the dirt removal pump 21 is connected to the liquid inlet of the filter 13, and the second shut-off valve 22 is connected to the second liquid outlet of the filter 13.

[0055] In this embodiment, the filter screen in the second filter 13 can be tilted. Specifically, the line connecting the liquid inlet and the first liquid outlet of the filter 13 forms an acute angle with the filter screen.

[0056] By setting up a cleaning pump 21, external fluid can be directly input into the water circulation loop to flush the filter 13, resulting in less fluid energy loss and facilitating a more thorough cleaning of the residue on the filter screen. The second shut-off valve 22 controls the opening and closing of the second liquid outlet of the filter 13. When the second shut-off valve 22 is closed, the second liquid outlet of the filter 13 is blocked, preventing water entering the filter 13 from exiting through the outlet. When the second shut-off valve 22 is open, the second liquid outlet of the filter 13 is open, allowing water entering the filter 13 to exit through the outlet. Therefore, when the filter 13 needs to be cleaned using the filter screen cleaning device, the cleaning pump 21 can be turned on to inject water into the filter 13, and the second shut-off valve 22 can be opened while the first shut-off valve 14 is closed. This ensures that the flushed water flows only from the second liquid outlet and not from the first liquid outlet, effectively removing water mixed with dirt and blockages.

[0057] like Figure 1 As shown, preferably, the filter cleaning device further includes a cleaning water tank 24, the inlet of the dirt removal pump 21 is connected to the cleaning water tank 24, and the outlet of the second shut-off valve 22 is connected to the cleaning water tank 24.

[0058] It should be noted that the inlet of the sludge pump 21 is connected to the cleaning water tank 24, and the outlet of the second shut-off valve 22 is also connected to the cleaning water tank 24. However, since the cleaning water tank 24 is large, the sewage discharged from the second shut-off valve 22 to the cleaning water tank 24 can settle in the cleaning water tank 24, and the dirt and blockage fall to the bottom of the cleaning water tank 24 and will not be sucked in by the sludge pump 21.

[0059] By setting up a cleaning water tank 24 to connect with the inlet of the sludge pump 21 and the outlet of the second shut-off valve 22, water can be directly pumped from the cleaning water tank 24 by the sludge pump 21 to rinse the filter 13. Since the sewage containing dirt and blockage discharged after rinsing the filter 13 can be settled, and the rinsing interval is sufficient to achieve relatively complete sedimentation, there is no need to pump water again for rinsing each time, thus saving water resources.

[0060] Of course, in another implementation, the sewage pump 21 can be connected to an external water source, or the sewage from the outlet of the second shut-off valve 22 can be discharged.

[0061] like Figure 1 As shown, preferably, the filter cleaning device further includes a third shut-off valve 23, which is located between the outlet of the dirt removal pump 21 and the water circulation loop.

[0062] Specifically, the third shut-off valve 23 is located between the outlet of the sewage pump 21 and the connection point between the outlet pipeline of the sewage pump 21 and the water circulation loop.

[0063] By setting the third shut-off valve 23, the connection between the sewage pump 21 and the water circulation loop can be controlled independently. When the sewage pump 21 is disconnected from the water circulation loop, the normal operation of the water circulation loop will not be affected. When the filter 13 does not need to be cleaned, both the second shut-off valve 22 and the third shut-off valve 23 can be closed to isolate the mutual influence between the water circulation loop and the filter cleaning device, ensuring the normal operation of the water circulation loop.

[0064] like Figure 1 As shown, preferably, the water circulation loop further includes a fourth shut-off valve 15, which is located between the heat exchanger 12 and the connection point of the third shut-off valve 23 with the water circulation loop.

[0065] By setting a fourth shut-off valve 15 in the water circulation loop, when the filter cleaning device cleans the filter screen, the fourth shut-off valve 15 is closed and, together with the first shut-off valve 14, the rest of the water circulation loop is isolated from the area involved in the cleaning, thus avoiding the influence of the cleaning liquid.

[0066] Preferably, the water pump 11 is a variable frequency water pump 11.

[0067] By setting up a variable frequency water pump 11, the duty cycle of the water pump 11 can be obtained. Therefore, the water operation status in the water circulation loop can be determined based on the duty cycle of the drive signal of the water pump 11, so as to determine whether the filter 13 needs to be cleaned.

[0068] Among them, the first shut-off valve 14, the second shut-off valve 22, the third shut-off valve 23, and the fourth shut-off valve 15 mentioned above can all be electrically operated two-way valves. Figure 2 As shown, in another implementation, an electrically operated three-way valve 25 can be installed at the connection point between the output pipeline of the sewage pump 21 and the water circulation loop. One port of the electrically operated three-way valve 25 is connected to the heat exchanger 12, one port is connected to the filter 13, and the other port is connected to the outlet of the sewage pump 21. This electrically operated three-way valve 25 can switch between connecting the heat exchanger 12 and the filter 13, and between connecting the sewage pump 21 and the filter 13.

[0069] Furthermore, in this embodiment, the water-based air conditioning system also includes a refrigerant system, which comprises an electronic expansion valve 32, a finned heat exchanger 31, a compressor 33, and a plate heat exchanger connected in sequence. The plate heat exchanger is used for heat exchange with the circulating water in the water circulation loop. When the water circulation loop needs heating, the refrigerant system transfers heat to the water circulation loop through the plate heat exchanger. When the water circulation loop needs cooling, the circulating water in the water circulation loop transfers heat to the refrigerant system through the plate heat exchanger.

[0070] The operating principle of this embodiment is as follows:

[0071] When the water circulation loop is in operation, the first shut-off valve 14 and the fourth shut-off valve 15 are open, while the second shut-off valve 22 and the third shut-off valve 23 are closed. The water circulation loop is open. Therefore, under the action of the water pump 11, the circulating water is sent to the heat exchanger 12, where it exchanges heat with the refrigerant. Then, it flows through the fourth shut-off valve 15 and is filtered by the filter screen of the filter 13 to remove the filter residue, preventing it from returning to the water pump 11.

[0072] When cleaning of filter 13 is required, the first shut-off valve 14 and the fourth shut-off valve 15 are closed, the second shut-off valve 22 and the third shut-off valve 23 are opened, and the water pump 11 is turned off. The sludge removal pump 21 turns on, drawing water from the cleaning water tank 24 and feeding it into filter 13 through the third shut-off valve 23 to rinse the filter screen. The surface of the filter screen is rinsed to remove blockages, and the water flows into the cleaning water tank 24 through the second liquid outlet and the second shut-off valve 22. Because the cleaning water tank 24 is relatively large, it allows blockages to settle without consuming new water.

[0073] Example 2:

[0074] like Figure 3 As shown, Embodiment 2 of the present invention also provides a filter cleaning control method for a water system air conditioner, applied to the above-mentioned water system air conditioner, the control method including:

[0075] S210, obtain the feedback duty cycle P of water pump 11 and the absolute value of temperature difference ΔT of water circulation loop through heat exchanger 12;

[0076] After the water system air conditioner is turned on, the water pump 11 can begin the judgment process as soon as it starts. Once the water flow detection is successful, the feedback duty cycle P of the water pump 11 is detected, and then detected once every time interval t1. The value of t1 ranges from 5 min to 8 min.

[0077] In this embodiment, the water pump 11 is a variable frequency water pump. The control of the variable frequency water pump involves two important parameters—the target input duty cycle T0 and the feedback duty cycle P. The water pump 11 adjusts its operating speed by controlling the target input duty cycle T0, thereby controlling the water flow rate. Different water flow rates correspond to different feedback duty cycles P.

[0078] In this embodiment, the refrigerant system operates as follows: the compressor compresses the refrigerant, which flows through a plate heat exchanger, then through an electronic expansion valve 32, then through a finned heat exchanger 31, and finally into the compressor 33. In the refrigerant system, the refrigerant absorbs heat from the air through the finned heat exchanger 31 and transfers this heat to the circulating water in the water circulation loop through the plate heat exchanger, thus raising the temperature of the circulating water. Therefore, the outlet temperature T2 of the plate heat exchanger is greater than the inlet temperature T1, and ΔT = T2 - T1. The outlet temperature T2 of the plate heat exchanger is measured by the plate heat exchanger outlet temperature sensor 16 located at the plate heat exchanger outlet, and the inlet temperature T1 is measured by the plate heat exchanger inlet temperature sensor 17 located at the plate heat exchanger inlet.

[0079] S220. Based on the comparison between the feedback duty cycle P and the first preset duty cycle, and the comparison between the absolute value of the temperature difference ΔT and the first preset temperature difference, control the filter cleaning device to clean the filter 13.

[0080] Under normal, unblocked conditions, the target input duty cycle T0 and the feedback duty cycle P are in one-to-one correspondence for the same pipeline. When filter 13 becomes clogged, the resistance to water circulation increases, the water flow rate decreases, and the corresponding feedback duty cycle P decreases. When the feedback duty cycle P of water pump 11 falls below a certain set value, such as below the first preset duty cycle, it indicates that the filter screen is severely clogged, and the automatic cleaning device needs to be activated.

[0081] Specifically, the standard feedback duty cycle corresponding to a certain target input duty cycle T0 is P0. Therefore, the first preset duty cycle can be expressed as P0 + ΔP, where the value range of ΔP is [5%, 10%].

[0082] With a fixed input to compressor 33, at the same outdoor ambient temperature, and with a constant amount of heat absorbed by the refrigerant through finned heat exchanger 31, and a stable system water flow rate, ΔT also remains stable. However, when the water flow rate in the water circulation loop decreases, i.e., when filter 13 becomes clogged, ΔT will increase. The heat generated by the refrigerant system cannot be transferred to the circulating water in the water circulation loop in a timely manner through heat exchange, leading to an increase in the condensing temperature of the condensing system, increased power consumption, and reduced energy efficiency. The first preset temperature difference value can be expressed as T. p +△T c Among them, T p The standard temperature difference, ΔT c This is the preset temperature difference deviation value. p The value range of T is [5℃, 8℃]. c The value range is [2℃, 5℃].

[0083] When P≥P0+△P and △T<T p If the water flow is clear, no action is needed, and the water system air conditioner should remain in its current state.

[0084] When P < P0 - △P and △T > T p +△T c If the detected feedback duty cycle P of the water pump 11 is too small compared to the first preset duty cycle, the corresponding water flow rate is also small, the inlet and outlet water temperature difference increases, and there is a blockage in the water supply pipeline, affecting the heat exchange of the unit. This indicates that the filter 13 is blocked, and the filter cleaning device is immediately activated.

[0085] The filter cleaning device for controlling the filter screen cleaning includes the following components for cleaning filter 13:

[0086] S221, control the first shut-off valve 14 to open, control the water pump 11 to close, control the sewage pump 21 to start, and control the second shut-off valve 22 to open.

[0087] When cleaning of filter 13 is required, the first shut-off valve 14 and the fourth shut-off valve 15 are closed, the second shut-off valve 22 and the third shut-off valve 23 are opened, and the water pump 11 is turned off. The cleaning pump 21 turns on, drawing water from the cleaning water tank 24 and feeding it into filter 13 through the third shut-off valve 23 to rinse the filter screen. The surface of the filter screen is rinsed to remove blockages, and the water flows into the cleaning water tank 24 through the second liquid outlet and the second shut-off valve 22.

[0088] The filter cleaning device 13 for controlling the filter screen cleaning also includes:

[0089] S223. If the cleaning time of filter 13 reaches the preset time t2, control the first shut-off valve 14 to open, control the water pump 11 to start, control the dirt pump 21 to close, and control the second shut-off valve 22 to open.

[0090] Obtain the feedback duty cycle P of water pump 11;

[0091] Based on the comparison between the feedback duty cycle P and the second preset duty cycle, the filter cleaning device is controlled to continue cleaning the filter 13.

[0092] The preset duration t2 can be [20min, 30min]. The second preset duty cycle can be expressed as P0 + ΔP.

[0093] Specifically, when P ≥ P0 + ΔP, it indicates that the filter screen has been cleaned and the unit can continue to operate normally. When P < P0 + ΔP, it indicates that the filter screen is still clogged with dirt and requires further cleaning.

[0094] Preferably, controlling the first shut-off valve 14 to open can control the water pump 11 to start, control the sewage pump 21 to shut down, and control the second shut-off valve 22 to open.

[0095] The feedback duty cycle P of the water pump 11 and the absolute value of the temperature difference ΔT of the water circulation loop through the heat exchanger 12 are obtained.

[0096] Based on the comparison between the feedback duty cycle P and the second preset duty cycle, and the comparison between the absolute value of the temperature difference ΔT and the second preset temperature difference value, the filter cleaning device is controlled to continue cleaning the filter 13.

[0097] That is, after the cleaning time reaches the preset time t2, when the water circulation loop is restarted for testing, in addition to obtaining the feedback duty cycle P, the absolute value of the temperature difference ΔT after passing through the heat exchanger 12 is also obtained, so as to obtain the operating status of the water circulation loop more accurately and to grasp the clogging status of the filter 13.

[0098] In this embodiment, the second preset temperature difference value is T. p That is, satisfying P≥P0+△P and △T<T p At this time, rinsing will cease, and the water circulation loop will continue to operate.

[0099] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

[0100] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising" or any other variations thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0101] In the above embodiments, descriptions of directions such as "up" and "down" are based on the accompanying drawings.

[0102] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0103] Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A water system air conditioner, characterized in that, The system includes a water circulation loop and a filter cleaning device. The water circulation loop includes a water pump (11), a heat exchanger (12), and a filter (13) connected in sequence. The filter cleaning device is connected to the filter (13). The filter (13) has a liquid inlet and two liquid outlets—a first liquid outlet and a second liquid outlet. The line connecting the liquid inlet and the first liquid outlet of the filter (13) forms an acute angle with the filter screen of the filter (13). The water circulation loop includes a first shut-off valve (14), which is located between the first liquid outlet and the water pump (11). The filter cleaning device includes a dirt removal pump (21) and a second shut-off valve (22). The outlet of the dirt removal pump (21) is connected to the liquid inlet of the filter (13), and the second shut-off valve (22) is connected to the second liquid outlet of the filter (13).

2. The water system air conditioner according to claim 1, characterized in that, The filter cleaning device also includes a cleaning water tank (24), the inlet of the dirt removal pump (21) is connected to the cleaning water tank (24), and the outlet of the second shut-off valve (22) is connected to the cleaning water tank (24).

3. The water system air conditioner according to claim 1, characterized in that, The filter cleaning device also includes a third shut-off valve (23), which is located between the outlet of the sewage pump (21) and the water circulation loop.

4. The water system air conditioner according to claim 3, characterized in that, The water circulation loop also includes a fourth shut-off valve (15) located between the heat exchanger (12) and the connection point of the third shut-off valve (23) with the water circulation loop.

5. The water system air conditioner according to any one of claims 1-4, characterized in that, The water pump (11) is a variable frequency water pump (11).

6. A method for controlling the cleaning of a filter screen in a water system air conditioner, characterized in that, The water system air conditioner of claim 5, wherein the filter cleaning control method of the water system air conditioner includes: Obtain the feedback duty cycle of the water pump (11) and the absolute value of the temperature difference of the water circulation loop through the heat exchanger (12); Based on the comparison between the feedback duty cycle and the first preset duty cycle, and the comparison between the absolute value of the temperature difference and the first preset temperature difference value, the filter cleaning device is controlled to clean the filter (13).

7. The water system air conditioner filter cleaning control method according to claim 6, characterized in that, Controlling the filter cleaning device to clean the filter (13) includes: The first shut-off valve (14) is opened, the water pump (11) is shut off, the sewage pump (21) is started, and the second shut-off valve (22) is opened.

8. The water system air conditioner filter cleaning control method according to claim 7, characterized in that, Controlling the filter cleaning device to clean the filter (13) further includes: If the time for cleaning the filter (13) reaches the preset duration, the first shut-off valve (14) is opened, the water pump (11) is started, the sewage pump (21) is closed, and the second shut-off valve (22) is disconnected. Obtain the feedback duty cycle of the water pump (11); Based on the comparison between the feedback duty cycle and the second preset duty cycle, the filter cleaning device is controlled to continue cleaning the filter (13).

9. The water system air conditioner filter cleaning control method according to claim 8, characterized in that, By controlling the first shut-off valve (14) to open, the water pump (11) can be started, the sewage pump (21) can be shut off, and the second shut-off valve (22) can be opened. Obtain the feedback duty cycle of the water pump (11) and the absolute value of the temperature difference of the water circulation loop through the heat exchanger (12); Based on the comparison between the feedback duty cycle and the second preset duty cycle, and the comparison between the absolute value of the temperature difference and the second preset temperature difference value, the filter cleaning device is controlled to continue cleaning the filter (13).

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