Ice melting structure and control method thereof, ice storage unit and air conditioning system

Abstract

The present invention provides an ice melting structure and a control method thereof, an ice storage unit and an air conditioning system, which relate to the field of cold storage and solve the technical problem that the ice melting structure in the ice storage unit has poor stability under low load. The ice melting structure includes an adjusting component and a heat exchanger. The heat exchanger and the pump body and valve connected thereto are located on a first branch connected to the ice storage tank. The adjusting component is located on a second branch connected to the ice storage tank, and is used to adjust the flow rate of the coolant flowing to the first branch after heat exchange with the ice storage tank. The above-mentioned ice melting structure diverts the coolant through the adjusting component located on the second branch. When the user's terminal load is low, the pump body can be adjusted to the lowest stable frequency, and the valve opening can be reduced to the minimum stable opening. If the low load at the user end cannot be met, the adjusting component is turned on and its opening is increased to further meet the low load demand at the user end. The pump body operation and the valve opening are in a reasonable range to ensure the stability of the ice melting structure operation.

Description

Technical Field

[0001] The present invention relates to the field of cold storage technology, and in particular to an ice melting structure and a control method thereof, an ice cold storage unit and an air conditioning system. Background Art

[0002] Ice storage air conditioners use the low electricity consumption period at night when the power load is very low, and use electric refrigeration to freeze the cold storage medium into ice. The cold energy is stored by using the sensible heat and latent heat characteristics of the cold storage medium. During the peak electricity consumption period, the ice is melted to release the cold energy to meet the cooling load requirements of the air conditioner.

[0003] Ice storage technology is increasingly being used in practical projects. In the prior art, ice is placed in an ice storage tank, and a coolant (commonly used ethylene glycol) flows in a coil. When it reaches the ice storage tank, the ice melts and takes away the cold energy inside, then flows to a heat exchanger to exchange heat with chilled water, transferring the cold energy to the air conditioning chilled water.

[0004] The applicant has found that the prior art has at least the following technical problems: In the actual operation control process, the load at the user end is constantly changing. When the load at the user end decreases, the traditional control method is to first adjust the frequency of the water pump until the frequency of the water pump drops to the minimum, and then start to adjust the valve opening; or when the opening of the valve group is closed to the minimum, the water pump frequency is reduced. It is easy to cause the water pump to run in an extremely low efficiency range for a long time, and too small a valve opening will also cause the valve control to become unstable.

[0005] Therefore, in the existing ice melting structure, when the user's terminal load is reduced to a certain level, the water pump is prone to control instability when it runs at the minimum frequency for a long time and the valve is used at the minimum opening, resulting in poor stability of the entire ice storage unit. Summary of the invention

[0006] The object of the present invention is to provide an ice melting structure and a control method thereof, an ice storage unit and an air-conditioning system, so as to solve the technical problem in the prior art that the ice melting structure in the ice storage unit has poor stability under low load; the many technical effects that can be produced by the preferred technical scheme among the many technical schemes provided by the present invention are detailed as follows.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The ice melting structure provided by the present invention comprises an adjusting component and a heat exchanger, wherein:

[0009] The heat exchanger and the pump body and valve connected thereto are located on a first branch connected to the ice storage tank. The regulating component is located on a second branch connected to the ice storage tank and is used to regulate the flow of the coolant flowing to the first branch after heat exchange with the ice storage tank.

[0010] Preferably, among the first branch and the second branch, the inlet end of the second branch is arranged close to the outlet end of the ice storage tank.

[0011] Preferably, the inlet end of the regulating component is communicated with the outlet end of the ice storage tank, and the outlet end of the regulating component is communicated with the inlet end of the ice storage tank.

[0012] Preferably, there is a water outlet main pipe at the outlet end of the ice storage tank, and there is a water inlet main pipe at the inlet end of the ice storage tank, wherein:

[0013] The water inlet ends of the first branch and the second branch are both connected to the water outlet main pipe, and the water outlet ends of the first branch and the second branch are both connected to the water inlet main pipe.

[0014] Preferably, the regulating component is a regulating valve.

[0015] Preferably, the valve is connected to the inlet end of the heat exchanger, and the pump body is connected to the outlet end of the heat exchanger.

[0016] Preferably, the pump body connected to the heat exchanger is a variable frequency water pump.

[0017] Preferably, the regulating component and the valve connected to the heat exchanger are both throttle valves with adjustable opening.

[0018] The present invention also provides a control method based on the above ice melting structure, comprising the following steps:

[0019] S1: Setting the minimum stable frequency P of the pump body and the minimum stable opening L of the valve;

[0020] S2: When the user terminal load decreases, the frequency of the pump body is reduced and / or the opening of the valve is reduced;

[0021] S3: When the frequency of the pump body is reduced to the lowest stable frequency P, and the valve opening is reduced to the minimum stable opening L, and the refrigerant flow rate flowing into the heat exchanger is still greater than the user's terminal load demand, the regulating component is opened and its opening is increased.

[0022] The present invention also provides an ice storage unit, comprising an ice storage tank and the above-mentioned ice melting structure connected to the ice storage tank.

[0023] The present invention also provides an air conditioning system, characterized in that it comprises the above-mentioned ice storage unit.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The ice-melting structure provided by the present invention diverts the coolant flowing into the first branch through the regulating component located on the second branch. When the user's terminal load is low, the pump body can be adjusted to the lowest stable frequency instead of the minimum limit frequency, and the valve opening can be reduced to the minimum stable opening instead of the minimum limit opening. If the low load at the user end cannot be met, the regulating component can be opened and the opening of the regulating component can be increased to further meet the low load demand at the user end. The operation of the pump body and the opening of the valve are in a reasonable range to ensure the stability of the operation of the ice-melting structure.

[0026] 2. The ice-melting structure control method provided by the present invention is based on the above-mentioned ice-melting structure, so it also has the advantages of being able to meet the low-load requirements of the user end and ensuring the stability of the structural movement.

[0027] 3. The ice storage unit provided by the present invention also has the advantage of stable and reliable structural operation because it includes the above-mentioned ice melting structure.

[0028] 4. The air conditioning system provided by the present invention, including the above-mentioned ice storage unit, can meet the low-load demand of the user end and also has the advantage of reliable operation stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a schematic diagram of the principle of the ice melting structure of the present invention;

[0031] In the figure, 1, ice storage tank; 2, heat exchanger; 3, pump body; 4, valve; 5, regulating valve; 6, user terminal; 7, first branch; 8, second branch; 91, water inlet main pipe; 92, water outlet main pipe. DETAILED DESCRIPTION

[0032] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms "center", "length", "width", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "side" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0034] In the prior art, when the user's terminal load is low, the only way is to reduce the frequency of the pump connected to the heat exchanger and the opening of the valve connected to the heat exchanger. On the one hand, when the frequency of the pump is reduced to the minimum and the opening of the valve is adjusted to the minimum, the operation of the pump and the valve is very unstable, and there is a problem of control instability, which affects the stability of the entire system; on the other hand, when the user's terminal load continues to decrease, the method of adjusting the pump and the valve may not meet the requirements.

[0035] Example 1

[0036] See also Figure 1 As shown, the direction of the arrow in the figure indicates the flow direction of the coolant; this embodiment provides an ice melting structure, including a regulating component and a heat exchanger 2, wherein: the heat exchanger 2 and the pump body 3 and the valve 4 connected thereto are located on the first branch 7 connected to the ice storage tank 1, and the regulating component is located on the second branch 8 connected to the ice storage tank 1, and is used to regulate the flow of the coolant after heat exchange with the ice storage tank 1 to the first branch 7.

[0037] See also Figure 1 As shown, the user terminal 6 is connected to the heat exchanger 2, and chilled water flows between the two. The chilled water exchanges heat with the secondary coolant in the heat exchanger 2, and the chilled water obtains the cooling capacity of the secondary coolant. When the load of the user terminal 6 is reduced, it is necessary to reduce the flow rate of the secondary coolant flowing into the heat exchanger 2 after heat exchange with the ice storage tank to reduce the cooling capacity transferred to the chilled water.

[0038] The first branch 7 and the second branch 8 are arranged in parallel, and the second branch 8 can divert the coolant after heat exchange in the ice storage tank 1. When the coolant flowing into the second branch 8 increases, the coolant flow flowing into the first branch 7 decreases.

[0039] The ice-melting structure of the present embodiment diverts the coolant flowing into the first branch 7 through the regulating component located on the second branch 8. When the load of the user terminal 6 is low, the pump body 3 can be adjusted to the lowest stable frequency instead of the minimum limit frequency, and the opening of the valve 4 can be reduced to the minimum stable opening instead of the minimum limit opening. If the low load at the user end cannot be met, the regulating component can be opened and the opening of the regulating component can be increased to further meet the low load demand of the user terminal 6. The operation of the pump body 3 and the opening of the valve 4 are in a reasonable range to ensure the stability of the operation of the ice-melting structure.

[0040] As an alternative embodiment, see Figure 1 As shown, among the first branch 7 and the second branch 8 , the inlet end of the second branch 8 is arranged close to the outlet end of the ice storage tank 1 .

[0041] The above structure enables the coolant after heat exchange with the ice storage tank 1 to first pass through the second branch 8 after the regulating component is opened, and then be diverted to the second branch 8, thereby reducing the flow into the first branch 7.

[0042] As an alternative embodiment, see Figure 1 , adjustment components ( Figure 1 The inlet end of the regulating valve 5) is connected to the outlet end of the ice storage tank 1, and the outlet end of the regulating component is connected to the inlet end of the ice storage tank 1.

[0043] The coolant after heat exchange with the ice storage tank 1 can enter from the inlet end of the regulating component and flow back to the inlet end of the ice storage tank 1 through the outlet end of the regulating component, thereby realizing the flow circulation of the coolant without involving the loss of the coolant.

[0044] As an alternative embodiment, see Figure 1 As shown, there is a water outlet main pipe 92 at the outlet end of the ice storage tank 1, and there is a water inlet main pipe 91 at the inlet end of the ice storage tank 1, wherein: the water inlet ends of the first branch 7 and the second branch 8 are both connected to the water outlet main pipe 92, and the water outlet ends of the first branch 7 and the second branch 8 are both connected to the water inlet main pipe 91.

[0045] The water outlet main pipe 92 connected to the outlet end of the ice storage tank 1 is connected to the water inlet ends of the first branch 7 and the second branch 8. There is no need to connect the first branch 7 and the second branch 8 to the outlet end of the ice storage tank 1 respectively. The pipeline structure is compact, which is convenient for pipeline connection and operation; the water inlet main pipe 91 connected to the inlet end of the ice storage tank 1 is connected to the water outlet ends of the first branch 7 and the second branch 8, which also makes the pipeline structure more compact and saves costs.

[0046] See also Figure 1 Since the pump body 3 allows the coolant to flow toward the water inlet main pipe 91 under a certain pressure, the coolant flowing out of the second branch 8 will not flow toward the first branch 7.

[0047] As an optional implementation, the regulating component in this embodiment is a regulating valve 5. Any valve with adjustable opening in the prior art can be used, and no limitation is made here.

[0048] Since the second branch 8 can divert the coolant, when the load at the user terminal 6 continues to decrease, the opening of the regulating valve 5 can be opened and increased without reducing the opening of the regulating valve 5 to the minimum. Therefore, the operation of the regulating valve 5 is also stable and reliable.

[0049] As an alternative embodiment, see Figure 1 As shown, the valve 4 is connected to the inlet end of the heat exchanger 2 , and the pump body 3 is connected to the outlet end of the heat exchanger 2 .

[0050] The flow rate of the brine flowing into the heat exchanger 2 is adjusted by adjusting the opening of the valve 5 , and the flow rate of the brine is adjusted by adjusting the frequency of the pump body 3 .

[0051] As an optional implementation, the pump body 3 connected to the heat exchanger 2 in this embodiment is a variable frequency water pump.

[0052] As an optional implementation, the regulating component in this embodiment and the valve 4 connected to the heat exchanger 2 are both throttle valves with adjustable opening.

[0053] By reducing the opening of the valve 4 on the first branch 7, opening the regulating component (regulating valve 5) and increasing the opening of the regulating component (regulating valve 5), the flow of the refrigerant flowing into the heat exchanger 2 is adjusted to meet the low load demand of the user terminal 6 and ensure that the opening of the valve 4 can be in a reasonable range for stable operation.

[0054] Example 2

[0055] This embodiment provides a control method based on the above ice melting structure, comprising the following steps:

[0056] S1: Set the minimum stable frequency P of the pump body 3 and the minimum stable opening L of the valve 4;

[0057] S2: When the load of the user terminal 6 decreases, the frequency of the pump body 3 is reduced and / or the opening of the valve 4 is reduced;

[0058] S3: When the frequency of the pump body 3 is reduced to the lowest stable frequency P, and the opening of the valve 4 is reduced to the minimum stable opening L, and the flow rate of the refrigerant flowing into the heat exchanger 2 is still greater than the load demand of the user terminal 6, the regulating component is opened and its opening is increased.

[0059] Among them, the minimum stable frequency P of the pump body 3 can be set according to the variable frequency water pump change curve; it means that at this frequency, the operating efficiency of the pump body is still in a good range, rather than the minimum limit frequency of the pump body. Since different types of pump bodies have different rated flow rates, no specific restrictions are made here. For example, 10%-30% of the rated flow rate of the pump body can be used as the minimum flow limit, and the specific value is determined according to the pump body selected for the actual project.

[0060] At the minimum stable opening L of the valve 4, the adjustment of the valve 4 will not be in an unstable state, and the minimum stable opening is not the minimum limit opening. The opening of the valve 4 can also be set to an opening corresponding to the minimum flow rate of 10%-30% of the pump body 3. The specific value is determined according to the actual situation.

[0061] The ice-melting structure control method provided in this embodiment is based on the above-mentioned ice-melting structure, so it also has the advantages of being able to meet the low-load requirements of the user terminal 6 and ensuring the stability of the structural movement.

[0062] As an optional implementation, in S2 , the frequency of the pump body 3 may be reduced first and then the opening of the valve 4 may be reduced, or the opening of the valve 4 may be reduced first and then the frequency of the pump body 3 may be reduced.

[0063] Specifically, during operation, when the load at the user terminal 6 gradually becomes smaller, the frequency of the variable frequency water pump (pump body 3) is adjusted to reduce the power of the pump body and reduce the flow rate of the refrigerant through the plate heat exchanger 2, thereby meeting the demand for reducing the terminal load.

[0064] When the terminal load is lower, the frequency of the pump body continues to decrease until it reaches the minimum stable frequency P set by the pump body. At this time, the frequency of the pump body is no longer reduced, but the opening of the valve 4 in the system is adjusted, and the opening of the valve 4 is gradually reduced until its minimum stable opening L, so that the flow of the refrigerant flowing through the plate heat exchanger 2 is reduced, thereby meeting the low load requirements of the user terminal 6. At this time, the operation of the variable frequency pump body is still in a relatively good efficiency range, and the opening of the valve 4 is still in a reasonable adjustment range, and it can also meet the low load requirements of the terminal.

[0065] If the load at the end is still decreasing at this time, open the regulating valve 5, gradually increase the opening of the regulating valve 5, and gradually increase the flow of the refrigerant flowing into the second branch 8. Then, the flow of the refrigerant flowing into the heat exchanger 2 continues to gradually decrease until the demand for low load at the end is met.

[0066] Example 3

[0067] This embodiment provides an ice storage unit, including an ice storage tank 1 and the above-mentioned ice melting structure connected to the ice storage tank 1.

[0068] The ice storage unit of this embodiment, because it includes the above-mentioned ice melting structure, also has the advantage of stable and reliable structural operation.

[0069] Example 4

[0070] This embodiment provides an air conditioning system, including the above-mentioned ice storage unit.

[0071] The air conditioning system of this embodiment, including the above-mentioned ice storage unit, can meet the low-load demand of the user terminal 6 and also has the advantage of reliable operation stability.

[0072] In the description of this specification, specific features, structures or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0073] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for controlling an ice melting structure, characterized in that: The ice melting structure includes an adjusting component and a heat exchanger, wherein: the heat exchanger and the pump body and valve connected thereto are located on a first branch connected to the ice storage tank, and the adjusting component is located on a second branch connected to the ice storage tank, and is used to adjust the flow rate of the coolant after heat exchange with the ice storage tank to the first branch; The control method comprises the following steps: S1: Setting the minimum stable frequency P of the pump body and the minimum stable opening L of the valve; S2: When the user terminal load decreases, the frequency of the pump body is reduced and / or the opening of the valve is reduced; S3: When the frequency of the pump body is reduced to the lowest stable frequency P, and the valve opening is reduced to the minimum stable opening L, and the refrigerant flow rate flowing into the heat exchanger is still greater than the user's terminal load demand, the regulating component is opened and its opening is increased.

2. The control method of the ice melting structure according to claim 1, characterized in that: In both the first branch and the second branch, the inlet end of the second branch is arranged close to the outlet end of the ice storage tank.

3. The control method of the ice melting structure according to claim 1 or 2, characterized in that: The inlet end of the regulating component is communicated with the outlet end of the ice storage tank, and the outlet end of the regulating component is communicated with the inlet end of the ice storage tank.

4. The control method of the ice melting structure according to claim 1 or 2, characterized in that: There is a water outlet main pipe at the outlet end of the ice storage tank, and there is a water inlet main pipe at the inlet end of the ice storage tank, wherein: The water inlet ends of the first branch and the second branch are both connected to the water outlet main pipe, and the water outlet ends of the first branch and the second branch are both connected to the water inlet main pipe.

5. The control method of the ice melting structure according to claim 1 or 2, characterized in that: The regulating component is a regulating valve.

6. The control method of the ice melting structure according to claim 1 or 2, characterized in that: The valve is connected to the inlet end of the heat exchanger, and the pump body is connected to the outlet end of the heat exchanger.

7. The control method of the ice melting structure according to claim 1 or 2, characterized in that: The pump body connected to the heat exchanger is a variable frequency water pump.

8. An ice storage unit, characterized in that: The invention comprises an ice storage tank and an ice melting structure connected to the ice storage tank, wherein the ice melting structure uses the control method of the ice melting structure according to any one of claims 1 to 7.

9. An air conditioning system, characterized in that: It includes the ice storage unit as claimed in claim 8.

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