Device for reducing stagnant water in the water supply pipes used for washing machine performance testing

Abstract

This utility model relates to a device for reducing the amount of stagnant water in the water supply pipeline of a washing machine performance test. The device includes: a water supply tank with an inlet and a thermostatic control unit; a main circulation pipeline connected at both ends to the water supply tank; a circulation branch pipeline connected at both ends to the main circulation pipeline, with the main circulation pipeline located between the two ends of the branch pipeline in a horizontal arrangement; and a stagnant water pipeline whose inlet is connected to the middle of the branch circulation pipeline via a three-way valve, and whose outlet is connected to the inlet of the washing machine under test. A flow meter is installed on the stagnant water pipeline. This utility model, by setting up circulation branch pipelines on the main circulation pipeline, avoids directly connecting the stagnant water pipeline to the main circulation pipeline, thereby reducing the length of the stagnant water pipeline, thus reducing the amount of stagnant water and improving test accuracy.

Description

Technical Field

[0001] This utility model relates to the field of washing machine performance testing technology, specifically to a device for reducing the amount of stagnant water in the water supply pipes for washing machine performance testing. Background Technology

[0002] As an essential household appliance, washing machines are subject to stringent market access requirements in most countries and regions worldwide. Before entering the market, products undergo a series of performance tests according to the standards and regulations of various countries. Among these, the International Electrotechnical Commission (IEC) standard IEC 60456:2024 is a crucial standard for washing machine performance testing. This standard requires that during washing machine performance testing, the water supply system configuration should ensure that the temperature of all water entering the inlet hose of the test washing machine is within a specified tolerance range, namely 15±2℃ or 60±2℃. However, as is well known, the washing machine inlet is always connected to a faucet, which is constantly open. The water flow is controlled by an automatic water valve at the washing machine inlet. In this case, the water in the pipeline between the faucet and the test water is considered stagnant water. Because this water remains in the pipeline without forming a circulation path, it will experience uncontrollable temperature fluctuations due to changes in the external environment, failing to meet the requirements for washing machine performance testing. Therefore, during testing, the amount of stagnant water should be minimized. According to section CL5.2.2.3 of the latest international standard IEC 60456:2024, the amount of stagnant water should be less than 250 mL. However, current testing equipment cannot meet this requirement, resulting in uncontrollable measurement errors in the laboratory test results. Summary of the Invention

[0003] The purpose of this invention is to overcome the defects of the prior art and provide a device for reducing the amount of stagnant water in the water supply pipe for washing machine performance testing.

[0004] To achieve the purpose of this utility model, this application provides the following technical solution.

[0005] In a first aspect, this application provides an apparatus for reducing stagnant water in the water supply pipes of a washing machine performance test, the apparatus comprising: Water supply tank: including water inlet and constant temperature control unit; The main circulating pipeline has its two ends connected to the water supply tank. Circulation branch pipeline: Both ends are connected to the circulation main pipeline, and the circulation main pipeline located between the two ends of the circulation branch pipeline is arranged horizontally; Dead water pipe: Its inlet is connected to the middle of the circulating branch pipe through a three-way valve, and its outlet is connected to the inlet of the washing machine to be tested. A flow meter is installed on the dead water pipe.

[0006] This application ensures that the water temperature in both the main circulation pipe and the branch circulation pipes remains constant and meets the testing requirements (adjusted by a thermostatic control unit in the water supply tank) by setting up circulation branch pipes on the main circulation pipe. In this way, stagnant water exists only in the stagnant water pipes within the entire testing device. By controlling the length and diameter of the stagnant water pipes, the amount of stagnant water can be controlled. Compared to directly connecting the stagnant water pipes to the main circulation pipe, this application reduces the length of the stagnant water pipes, thereby reducing the amount of stagnant water.

[0007] In one embodiment of the first aspect, a temperature sensor and a pressure sensor are provided in the middle of the circulating branch pipe, and the temperature sensor and pressure sensor are located at the front end of the inlet of the dead water pipe.

[0008] In one embodiment of the first aspect, the constant temperature control unit includes a controller, a heating unit disposed within the water supply tank, and a cooling unit disposed on the side wall of the water supply tank. The controller is connected to the temperature sensor and controls the opening and closing of the heating unit and the cooling unit. The heating unit can be a conventional heating wire, and its operation is achieved by controlling the flow of current through the heating wire. Of course, other heating units can also be used, as long as they can heat the water in the water supply tank. The cooling unit can be a cooling coil fixed to the side wall of the water supply tank, where a coolant at a lower temperature is circulated. The flow of the coolant is controlled by the controller. Of course, other cooling units can also be used, as long as they can cool the water in the water supply tank. Generally, when the ambient temperature is above 20°C, only the cooling unit needs to be used; when the ambient temperature is below 10°C, only the heating unit needs to be used. When the ambient temperature is between 10°C and 20°C, the heating unit or the cooling unit is selectively activated based on real-time monitoring by the temperature sensor to maintain the temperature of the washing machine's water inlet. More preferably, an agitator can be installed inside the water supply tank to ensure that the water temperature inside the tank is constant and uniform.

[0009] In one embodiment of the first aspect, the main circulation pipeline and the circulation branch pipelines are externally wrapped with a heat insulation layer. This arrangement facilitates water temperature regulation throughout the system.

[0010] In one embodiment of the first aspect, the circulating branch pipe is inverted U-shaped, comprising an inlet vertical pipe, a horizontal pipe, and an outlet vertical pipe, wherein the three-way valve is installed at the connection between the vertical and horizontal pipes. Since the sensors for detecting the washing machine's inlet water temperature and pressure are installed on the supply branch pipe, the horizontal pipe and the outlet vertical pipe in the circulating branch pipe should be installed on the side of the main circulating pipe in the direction of water flow (with the supply branch pipe as the directional reference point) during installation. In this design, after water circulates in the main circulating pipe, it can be diverted in the circulating branch pipes to achieve the full system flow water supply requirements of the main circulating pipe's large circulation and the circulating branch pipes' small circulation, thereby ensuring that the inlet water temperature meets the relevant test standards for fluctuation and dead water limitation.

[0011] In one embodiment of the first aspect, the diameter of the dead water pipe is 1-2 cm, and the length of the dead water pipe is <50 cm. Under these conditions, the maximum dead water content in the dead water pipe is 50π mL, i.e., <160 mL, which is far less than the standard requirement of 250 mL.

[0012] In one embodiment of the first aspect, the main circulation pipe is connected to multiple circulation branch pipes, and each circulation branch pipe is connected to a dead water pipe. This device can be used for performance testing of multiple washing machines, improving testing efficiency.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: This application reduces the length of the dead water pipe by setting up a circulation branch pipe on the main circulation pipe, thereby avoiding the direct connection of the dead water pipe to the main circulation pipe and thus reducing the amount of dead water and improving the accuracy of the test. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the device in this application.

[0015] In the attached diagram, 1 is the water supply tank, 11 is the water inlet, 12 is the cooling coil, 13 is the electric heater, 14 is the agitator, 2 is the main circulation pipeline, 3 is the circulation branch pipeline, 31 is the vertical inlet pipe, 32 is the horizontal pipe, 33 is the vertical outlet pipe, 4 is the dead water pipeline, 41 is the flow meter, 42 is the faucet, 5 is the temperature sensor, 6 is the pressure sensor, and 7 is the water pump. Detailed Implementation

[0016] Unless otherwise defined, the technical or scientific terms used in this specification and claims shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. All values ​​listed herein, ranging from the minimum to the maximum, refer to all values ​​obtained by incrementing the minimum and maximum values ​​by one unit when the difference between the minimum and maximum values ​​is more than two units.

[0017] The following describes specific embodiments of this utility model. It should be noted that, in order to provide a concise description, this specification cannot provide a detailed description of all features of the actual embodiments. Without departing from the spirit and scope of this utility model, those skilled in the art can modify and substitute the embodiments of this utility model, and the resulting embodiments are also within the protection scope of this utility model. Example

[0018] The embodiments of this utility model will be described in detail below. These embodiments are implemented based on the technical solution of this utility model and provide detailed implementation methods and specific operation processes. However, the protection scope of this utility model is not limited to the following embodiments. Example

[0019] A device for reducing stagnant water in the water supply pipes of washing machines for performance testing, its structure is as follows: Figure 1 As shown, it includes a water supply tank 1, a main circulation pipeline 2, multiple circulation branch pipelines 3 (three are used as an example in the figure) and multiple dead water pipelines 4, as detailed below.

[0020] The water supply tank 1 has an inlet 11 at the top, which is connected to tap water. When the water level in the water supply tank 1 is too low, the inlet 11 connects to the tap water to replenish the water supply tank 1. A cooling coil 12 is fixed to the inner wall of the water supply tank 1. The cooling coil 12 is filled with coolant, and the cooling coil is circulated and connected to an external cooling system (not shown in the figure). An electric heater 13 is located at the bottom of the water supply tank 1 to heat the water in the water supply tank 1. An agitator 14 is also installed inside the water supply tank 1, or a circulating water pump can be used to agitate the water in the water supply tank 1 to ensure uniform temperature. The water supply tank 1 is also equipped with a PLC controller to control the flow of coolant in the cooling coil 12 and the operation of the electric heater 13.

[0021] The two ends of the main circulation pipe 2 are connected to the bottom of the water supply tank 1, and a water pump 7 is installed on the main circulation pipe 2 to circulate water between the water supply tank 1 and the main circulation pipe 2. An insulation layer (not shown in the diagram) is wrapped around the outside of the main circulation pipe 2. The diameter of the main circulation pipe 2 should be DN40 or DN50, or adjusted according to the number of circulation branch pipes 3 connected to it (i.e., the number of washing machines to be tested simultaneously).

[0022] The circulating branch pipe 3 is inverted U-shaped and includes a vertical inlet pipe 31, a horizontal pipe 32, and a vertical outlet pipe 33 connected in sequence. The bottom of the vertical inlet pipe 31 and the vertical outlet pipe 33 are connected to the main circulating pipe 2, and the main circulating pipe 2 located between the vertical inlet pipe 31 and the vertical outlet pipe 33 is horizontally distributed. A three-way valve is installed at the connection between the vertical inlet pipe 31 and the horizontal pipe 32, and the remaining outlet of the three-way valve is connected to the dead water pipe 4. A temperature sensor 5 and a pressure sensor 6 are installed at the connection between the vertical inlet pipe 31 and the horizontal pipe 32. The circulating branch pipe 3 uses a DN15 or DN20 diameter pipe.

[0023] A three-way valve is connected to the bottom of the stagnant water pipe 4, and a faucet 42 is installed at the top, which is connected to the water inlet of the washing machine to be tested. A flow meter 41 is installed on the stagnant water pipe 4. In this embodiment, the stagnant water pipe 4 is a DN15 diameter pipe with a length of 40cm.

[0024] The working principle of the above device is as follows: (1) Since the inner diameter of the main circulation pipe 2 is much larger than the inner diameter of the circulation branch pipe 3 and the dead water pipe 4, when the washing machine under test takes water from the dead water pipe 4, it will not have a significant impact on the water pressure in the main circulation pipe 2. That is, there will be no mutual interference between the two washing machines under test.

[0025] (2) Under the action of water pump 7, the water in the entire circulating main pipeline 2 and circulating branch pipeline 3 is in a flowing state. As long as the water temperature in the water supply tank 1 is kept constant, it can be assumed that the water temperature in the circulating branch pipeline 3 is also constant, that is, controllable within the range of 15±2℃, which meets the test requirements. When the temperature sensor 5 detects that the water temperature in the circulating branch pipeline 3 is higher than 17℃, the PLC controller will control the cooling coil 12 to connect to the external cooling system, and the coolant will cool the water in the water supply tank 1. At this time, the electric heater 13 does not work. Similarly, when the temperature sensor 5 detects that the water temperature in the circulating branch pipeline 3 is lower than 13℃, the PLC controller will control the electric heater 13 to connect to the power supply to heat the water in the water supply tank 1. At this time, the cooling coil 12 is disconnected from the external cooling system. By this method, the constant water temperature can be ensured.

[0026] (3) When too many washing machines are tested at the same time, water pressure fluctuations will occur. At this time, the pressure sensor 6 will transmit the signal to the PLC controller. The PLC controller only needs to adjust the output power of the water pump 7 and increase the flow rate of water in the circulating main pipeline 2 to increase the water pressure and make the water pressure constant, which meets the test requirements.

[0027] (4) During the test, the faucet 42 is in the normally open state, and the water inlet is controlled by the water valve inside the washing machine. When the washing machine under test needs water, water enters the dead water pipe 4 from the vertical water inlet pipe 31, and finally enters the washing machine through the faucet 42. When the washing machine does not need water, only the water in the dead water pipe 4 becomes dead water. The volume of water in the dead water pipe 4 can be calculated as V = πr. 2 h = 3.14 * (0.75) 2 *40≈70.65mL, which is far less than the standard requirement of 250ml of stagnant water.

[0028] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. A device for reducing stagnant water in the water supply pipes of a washing machine performance test, characterized in that, The device includes: Water supply tank: including water inlet and constant temperature control unit; The main circulating pipeline has its two ends connected to the water supply tank. Circulation branch pipeline: Both ends are connected to the circulation main pipeline, and the circulation main pipeline located between the two ends of the circulation branch pipeline is arranged horizontally; Dead water pipe: Its inlet is connected to the middle of the circulating branch pipe through a three-way valve, and its outlet is connected to the inlet of the washing machine to be tested. A flow meter is installed on the dead water pipe.

2. The device for reducing the dead-leg volume in a laundry machine performance testing water supply conduit of claim 1, wherein, A temperature sensor and a pressure sensor are installed in the middle of the circulating branch pipe, and the temperature sensor and pressure sensor are located at the front end of the inlet of the dead water pipe.

3. The device for reducing the dead-leg volume in a laundry machine performance testing water supply conduit of claim 2, wherein, The constant temperature control unit includes a controller, a heating unit installed in the water supply tank, and a cooling unit installed on the side wall of the water supply tank. The controller is connected to the temperature sensor and controls the opening and closing of the heating unit and the cooling unit.

4. The device for reducing the dead-leg volume in a laundry machine performance testing water supply line of claim 1, wherein, The main circulation pipeline and the branch circulation pipeline are externally wrapped with a heat insulation layer.

5. The device for reducing the dead-leg volume in a laundry machine performance testing water supply line of claim 1, wherein, The circulating branch pipeline is inverted U-shaped and includes, in sequence, an inlet vertical pipe, a horizontal pipe, and an outlet vertical pipe. The three-way valve is installed at the connection between the water vertical pipe and the horizontal pipe.

6. The device for reducing the dead-leg volume in a laundry machine performance testing water supply line of claim 1, wherein, The diameter of the dead water pipe is 1~2cm, and the length of the dead water pipe is <50cm.

7. The device for reducing the dead-leg volume in a laundry machine performance testing water supply line of claim 1, wherein, The main circulation pipeline is connected to multiple circulation branch pipelines, and each circulation branch pipeline is connected to a dead water pipeline.

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