Control method of cooling-water machine

Abstract

The invention provides a control method of a cooling-water machine, which comprises the following steps: after the cooling-water machine is started, acquiring a temperature reduction rate at one end of a water receiving port of a water pipe, comparing the temperature reduction rate at one end of the water receiving port with a preset low-water-level temperature reduction rate vlow, and if the temperature reduction rate v at one end of the water receiving port is greater than or equal to the preset low-water-level temperature reduction rate vlow, starting the cooling-water machine; if the water level in the water tank reaches the preset low water level, the user is reminded to add water.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment technology, and in particular to a control method for a chiller. Background Technology

[0002] Existing chillers typically use a level sensor installed at the bottom of the water tank to detect water pressure and determine whether the tank is low on water. However, adding a level sensor not only increases costs, but the sensor also has errors, which can easily lead to false level readings. Summary of the Invention

[0003] The purpose of this invention is to provide a control method for a chiller, which measures the rate of temperature decrease at one end of the water pipe inlet and determines whether the water tank is at a low water level by measuring the rate of temperature decrease, thus solving the problem that the liquid level sensor in the prior art increases costs.

[0004] To achieve one of the above-mentioned objectives, one embodiment of the present invention provides a control method for a chiller. The chiller includes a water tank with an outlet and a water pipe communicating with the outlet. The water pipe has a water inlet at one end away from the outlet, and the height of the water inlet is lower than that of the water tank. The control method includes the following steps:

[0005] The chiller is started after receiving the water connection command;

[0006] Obtain the temperature decrease rate v at one end of the water pipe inlet, and compare the temperature decrease rate v at the inlet with the preset low water level temperature decrease rate v. 低 Compare;

[0007] If the temperature drop rate v at the water inlet is greater than or equal to the preset low water level temperature drop rate v 低 If so, the user will be prompted to add water.

[0008] As a further improvement to one embodiment of the present invention, a preset low water level temperature reduction rate v 低 The speed is 4-6℃ / s.

[0009] As a further improvement to one embodiment of the present invention, a preset low water level temperature reduction rate v 低 The low water level is when the water level in the tank is located at 1 / 5 of the tank's height from the bottom.

[0010] As a further improvement to one embodiment of the present invention, the temperature reduction rate v at one end of the water inlet is compared with the preset water shortage temperature reduction rate v. 缺 Compare;

[0011] If the rate of temperature decrease at the water inlet is greater than or equal to the preset rate of temperature decrease at the water shortage level, then... 缺If the system stops cooling, it will alert the user that the water tank is empty.

[0012] As a further improvement to one embodiment of the present invention, the preset rate of decrease in water level temperature v 缺 The speed is 0-2℃ / s.

[0013] As a further improvement of one embodiment of the present invention, the top end of the water pipe is not higher than the bottom end of the water tank.

[0014] As a further improvement of one embodiment of the present invention, if the temperature decrease rate v at one end of the water inlet is zero, then the cooling is stopped.

[0015] As a further improvement of one embodiment of the present invention, when the temperature decrease rate v at one end of the water inlet is zero, it is determined that there is no water in the water pipe.

[0016] As a further improvement of one embodiment of the present invention, the water pipe includes a spiral portion and a connecting portion connecting the spiral portion and the water outlet, wherein the spiral portion is spirally coiled into a cylindrical shape.

[0017] The chiller also includes an evaporator tube that is spirally coiled into a cylindrical shape. The outer diameter of the spiral shape formed by the evaporator tube matches the inner diameter of the spiral shape formed by the spiral portion, and the evaporator tube that is spirally coiled into a cylindrical shape is located inside the spiral portion of the water pipe.

[0018] As a further improvement of one embodiment of the present invention, the spiral portion and the liquid flow direction in the evaporator tube are consistent in the spiral extension direction of the evaporator tube.

[0019] One or more technical solutions provided by this invention have at least the following technical effects or advantages:

[0020] The chiller control method provided by this invention only requires measuring the temperature drop rate at the water inlet end of the water pipe and comparing it with a preset low water level temperature drop rate. If the temperature drop rate at the water inlet end is greater than or equal to the preset low water level temperature drop rate, the water level drops, reminding the user to add water. This control method does not require a liquid level sensor; it only utilizes changes in liquid pressure, resulting in minimal error. Attached Figure Description

[0021] Figure 1 This is a flowchart of the control method for a chiller in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the chiller in an embodiment of the present invention.

[0023] Figure 3 yes Figure 2 A top view of a medium-cooled water chiller.

[0024] Figure 4 yes Figure 3 Schematic diagram of cross section along line AA.

[0025] Figure 5 yes Figure 4 Enlarged view of section B in the middle.

[0026] 1. Water pipe; 11. Spiral part; 12. Connecting part; 2. Evaporator pipe; 3. Cooling cylinder; 31. First spiral groove; 32. Second spiral groove; 4. Water tank; 41. Water outlet; 42. Exhaust port; 43. Water inlet; 5. Water pump. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The terms used in this document, such as “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” indicating spatial relative positions, are used for illustrative purposes to describe the relationship of one unit or feature relative to another unit or feature as shown in the accompanying drawings. The terms “spatial relative positions” may be intended to include different orientations of the equipment in use or operation other than those shown in the figures.

[0029] For example, if the device in the figure is flipped, a unit described as being "below" or "under" other units or features will be "above" other units or features. Therefore, the exemplary term "below" can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or otherwise) and the spatially related descriptive terms used herein will be interpreted accordingly.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0031] Furthermore, it should be understood that although the terms "first," "second," etc., may be used herein to describe various elements or structures, the objects being described should not be limited by these terms. These terms are only used to distinguish these objects from one another. For example, a first helical groove may be referred to as a second helical groove, and similarly, a second helical groove may be referred to as a first helical groove, without departing from the scope of protection of this application.

[0032] This invention provides a control method for a chiller. The chiller includes a water tank 4 with an outlet 41 and a water pipe 1 connected to the outlet 41. The water pipe 1 has a water inlet at one end away from the outlet 41, and the height of the water inlet is lower than that of the water tank 4. The control method includes the following steps:

[0033] The chiller is started after receiving the water connection command;

[0034] Obtain the temperature decrease rate v at one end of the water inlet of water pipe 1, and compare the temperature decrease rate v at one end of the water inlet with the preset low water level temperature decrease rate v. 低 Compare;

[0035] If the temperature drop rate v at the water inlet is greater than or equal to the preset low water level temperature drop rate v 低 If so, the user will be prompted to add water.

[0036] Upon receiving a water intake command, the chiller is activated, and water flows in water pipe 1. The flow velocity in water pipe 1 varies depending on the water level in water tank 4 due to pressure. With the cooling capacity of the refrigeration system remaining constant, the lower the water level in water tank 4, the lower the water flow velocity in water pipe 1, and the faster the temperature decreases. Therefore, this invention modifies the temperature decrease rate v at the water intake end of water pipe 1 to match the preset low water level temperature decrease rate v0. 低 If the temperature decrease rate v at the water inlet is greater than or equal to the preset low water level temperature decrease rate v, then... 低 If the water level in pipe 1 is below the low water level, it indicates that the water flow is slow, and the user is reminded to add water.

[0037] The preset low water level temperature reduction rate is preset as follows: After determining the height of water tank 4, a low water level line is pre-defined. The temperature reduction rate when the liquid level in water tank 4 reaches this water level line is obtained, and this temperature reduction rate is set as the preset low water level temperature reduction rate v. 低 This embodiment is based on the water tank 4 having a height of approximately 150mm, and the preset low water level temperature reduction rate v is used. 低 The preferred temperature is 4-6℃ / s.

[0038] More preferably, the preset low water level temperature reduction rate v 低The low water level is the water level in water tank 4 located at 1 / 5 of the height of water tank 4 from the bottom.

[0039] In some embodiments, the temperature decrease rate v at one end of the water inlet is compared with the preset water shortage temperature decrease rate v. 缺 Compare; if the temperature decrease rate v at the water inlet is greater than or equal to the preset water shortage level temperature decrease rate v 缺 If the system stops cooling, it will alert the user that there is no water in water tank 4.

[0040] When the water level in water tank 4 is low, the user continues to draw water, and the water level in water tank 4 continues to decrease. During this continuous decrease, the temperature drop rate *v* at the water inlet is continuously measured and compared with the preset water shortage temperature drop rate *v*. 缺 The comparison is performed. If the temperature decrease rate v at the water inlet is greater than or equal to the preset water shortage temperature decrease rate v... 缺 If the signal is positive, it indicates that water tank 4 is low on water. At this point, cooling should be stopped and the user should be notified.

[0041] Preferably, the preset rate of decrease in water level temperature v 缺 The speed is 0-2℃ / s.

[0042] When water tank 4 is low on water, the temperature at the inlet drops rapidly at an instantaneous rate, then the rate of temperature drop decreases. Therefore, the preset rate of temperature drop at the low water level, v, is... 缺 Less than the preset low water level temperature decrease rate v 低 .

[0043] Furthermore, the top of water pipe 1 is not higher than the bottom of water tank 4. As shown in the figure, the outlet 41 of water tank 4 is located at the bottom of water tank 4. After water pipe 1 is connected to the inlet, it does not extend upwards. Therefore, the top of water pipe 1 is the end where water pipe 1 connects to outlet 41. The fact that the top of water pipe 1 is not higher than the bottom of water tank 4 ensures that the water in water tank 4 is completely used up, preventing warnings of low water level or water shortage even when there is still water in water tank 4.

[0044] Furthermore, if the temperature drop rate v at the water inlet is zero, the cooling system will stop. Even further, when the temperature drop rate v at the water inlet is zero, it is determined that there is no water in water pipe 1.

[0045] When the temperature at one end of the water inlet stops decreasing, that is, when the rate of temperature decrease is zero, there is no water in water pipe 1 that can exchange heat with the refrigerant, and the temperature will not change anymore. Therefore, it can be determined that there is no water in water pipe 1, and the refrigeration needs to be stopped.

[0046] In some embodiments, the water pipe 1 includes a spiral portion 11 and a connecting portion 12 connecting the spiral portion 11 and the water outlet 41. The spiral portion 11 is spirally coiled into a cylindrical shape. The chiller also includes an evaporator tube 2 spirally coiled into a cylindrical shape. The outer diameter of the spiral shape formed by the evaporator tube 2 matches the inner diameter of the spiral shape formed by the spiral portion 11, and the evaporator tube 2 spirally coiled into a cylindrical shape is disposed inside the spiral portion 11 of the water pipe 1.

[0047] The spiral portions 11 in both the evaporator tube 2 and the water pipe 1 that are close to the evaporator are set in a spiral shape and coiled into a hollow cylinder with a certain wall thickness (i.e., the diameter of the evaporator tube 2 or the spiral portion 11). The cylindrical structure formed by the evaporator tube 2 is set inside the cylindrical structure formed by the spiral portion 11 of the water pipe 1, so that the two are nested together. The evaporator tube 2 located on the inner side cools the water pipe 1 located on the outer side. The structure is simple and the installation is simple.

[0048] Preferably, in the length direction of the cylindrical structure formed by the spiral portion 11, a slit is formed on the inner side of adjacent spiral portions 11. Since the spiral portion 11 is spirally coiled, the slit formed on the inner side of the spiral portion 11 is also spiral. The evaporator tube 2 is disposed in the slit formed on the inner side of the spiral portion 11, so that the spiral portion 11 and the evaporator tube 2 are mutually restrained in the radial and axial directions of the cylindrical structure, so that the spiral portion 11 and the evaporator tube 2 are installed more tightly, thereby improving the cold energy transfer effect.

[0049] Furthermore, in the spiral extension direction of the evaporator tube 2, the spiral part 11 and the liquid flow direction in the evaporator tube 2 are consistent, so that the flow of refrigerant and water is synchronized with the heat exchange, the heat exchange efficiency is faster, and the cooling time is saved.

[0050] In some embodiments, the chiller further includes a hollow cooling cylinder 3 disposed between the spiral section 11 and the evaporator tube 2, the inner wall of the cooling cylinder 3 being provided with a first spiral groove 31, and the evaporator tube 2 being disposed within the first spiral groove 31.

[0051] A cooling cylinder 3 is provided between the spiral section 11 and the evaporator tube 2, and a first spiral groove 31 is provided on the inner wall of the cooling cylinder 3 so that the evaporator tube 2 is disposed in the first spiral groove 31. On the one hand, the cooling cylinder 3 can provide support between the spiral section 11 and the evaporator tube 2. On the other hand, the evaporator tube 2 is disposed in the first spiral groove 31, which increases the contact area between the evaporator tube 2 and the cooling cylinder 3, that is, increases the area of ​​cold energy transfer, thereby increasing the efficiency of cold energy transfer.

[0052] Furthermore, the outer wall of the cooling cylinder 3 is provided with a second spiral groove 32, and the spiral part 11 is disposed in the second spiral groove 32.

[0053] The second spiral groove 32 increases the contact area between the spiral part 11 and the cooling cylinder 3, further increasing the efficiency of cold energy transfer.

[0054] Preferably, the cross-sections of the first spiral groove 31 and the second spiral groove 32 are both semi-circular. The radius of the cross-section of the first spiral groove 31 matches the radius of the evaporator tube 2, and the radius of the cross-section of the second spiral groove 32 matches the radius of the spiral part 11.

[0055] The radius of the cross-section of the first spiral groove 31 matches the radius of the evaporator tube 2, allowing the evaporator tube 2 to fit snugly against the first spiral groove 31. The cooling energy from the evaporator tube 2 is directly transferred to the cooling cylinder 3 without passing through an air layer, thus reducing cooling energy loss caused by the air layer. Similarly, the radius of the cross-section of the second spiral groove 32 matches the radius of the spiral section 11, allowing the cooling energy from the evaporator tube 2 to be directly transferred to the water pipe 1 without passing through an air layer, also reducing cooling energy loss caused by the air layer.

[0056] More preferably, in the length direction of the cooling cylinder 3, the distance between adjacent spiral portions 11 does not exceed 1 mm, and the distance between adjacent evaporation tubes 2 does not exceed 1 mm.

[0057] Along the length of the cooling cylinder 3, the evaporator tube 2 and the spiral part 11 are wound around the inside and outside of the cooling cylinder 3 as much as possible, so that the cooling and heat conduction area of ​​the cooling cylinder 3 is large and uniform, and prevents the segmented situation of cooling-uncooled-cooled in the length of the cooling cylinder 3.

[0058] In some embodiments, the chiller further includes a water tank 4, which is provided with a water storage chamber and a water outlet 41 communicating with the water storage chamber. The water pipe 1 also includes a connecting part 12 that is spirally connected to the water outlet 41.

[0059] Water pipe 1 supplies water through water tank 4. One end of connecting part 12 is connected to spiral part 11, and the other end is connected to water outlet 41 of water tank 4. Water in water tank 4 flows through water outlet 41 to connecting part 12, and then to spiral part 11 to exchange heat with evaporator 2. This allows the water flowing through spiral part 11 to obtain cooling energy from evaporator 2 and lower its temperature, thus supplying water to users.

[0060] Furthermore, the water tank 4 is also equipped with an exhaust port 42, which is located on the top of the water tank 4. The exhaust port 42 is used to allow air to enter when the water in the water tank 4 flows into the water pipe 1, so as to balance the atmospheric pressure inside the water tank 4 and prevent the water from being unable to flow out due to negative pressure in the water storage chamber.

[0061] As shown in the figure, the vent 42 is located on the top end face of the water tank 4. In addition, the top end face of the water tank 4 is also provided with a water inlet 43. Of course, a through hole can be provided only on the top end face or the top of the side of the water tank 4 for adding water and venting.

[0062] Furthermore, the top of the spiral part 11 is not higher than the bottom of the water tank 4.

[0063] After the water flows out of the water pipe 1, the water pressure in the water tank 4 is used to press the water back into the water pipe 1 without the need for other pressurizing devices. The top of the spiral part 11 is not higher than the bottom of the water tank 4, which allows the water in the water tank 4 to be completely used up and avoids the problem of water always remaining at the bottom of the water tank 4 that cannot be drained.

[0064] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0065] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a chiller, characterized in that, The chiller includes a water tank with an outlet and a water pipe connected to the outlet. The water pipe has a water inlet at one end away from the outlet, and the height of the water inlet is lower than that of the water tank. The control method includes the following steps: The chiller is started after receiving the water connection command; Obtain the temperature decrease rate v at one end of the water pipe inlet, and compare the temperature decrease rate v at the inlet with the preset low water level temperature decrease rate v. 低 Compare; If the temperature drop rate v at the water inlet is greater than or equal to the preset low water level temperature drop rate v 低 If so, the user will be prompted to add water.

2. The control method for a chiller according to claim 1, characterized in that, Preset low water level temperature reduction rate v 低 The speed is 4-6℃ / s.

3. The control method for a chiller according to claim 2, characterized in that, Preset low water level temperature reduction rate v 低 The low water level is when the water level in the tank is located at 1 / 5 of the tank's height from the bottom.

4. The control method for a chiller according to claim 1, characterized in that, The temperature reduction rate v at one end of the water inlet is compared with the preset water shortage temperature reduction rate v. 缺 Compare; If the rate of temperature decrease at the water inlet is greater than or equal to the preset rate of temperature decrease at the water shortage level, then... 缺 If the system stops cooling, it will alert the user that the water tank is empty.

5. The control method for a chiller according to claim 4, characterized in that, Preset water level temperature reduction rate v 缺 The speed is 0-2℃ / s.

6. The control method for a chiller according to claim 4, characterized in that, The top of the water pipe is not higher than the bottom of the water tank.

7. The control method for a chiller according to claim 6, characterized in that, If the rate of temperature decrease v at the water inlet is zero, then the cooling system will stop.

8. The control method for a chiller according to claim 7, characterized in that, When the rate of temperature decrease v at one end of the water inlet is zero, it is determined that there is no water in the water pipe.

9. The control method for a chiller according to claim 1, characterized in that, The water pipe includes a spiral section and a connecting section that connects the spiral section and the water outlet. The spiral section is spirally coiled into a cylindrical shape. The chiller also includes an evaporator tube that is spirally coiled into a cylindrical shape. The outer diameter of the spiral shape formed by the evaporator tube matches the inner diameter of the spiral shape formed by the spiral portion, and the evaporator tube that is spirally coiled into a cylindrical shape is located inside the spiral portion of the water pipe.

10. The control method for a chiller according to claim 9, characterized in that, In the spiral extension direction of the evaporator tube, the spiral section and the liquid flow direction in the evaporator tube are consistent.

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