Method for reducing refrigerant striking force and noise of electronic expansion valve of multi-split air conditioner

Abstract

The invention relates to the technical field of air conditioner heat exchangers, in particular to a method for reducing refrigerant striking force and noise of an electronic expansion valve of a multi-split air conditioner. Refrigerant impact force and noise are reduced by prolonging the closing time of an electronic expansion valve of an indoor unit and controlling the frequency of a compressor to be adjusted in proportion; the opening degree of the electronic expansion valve when the temperature sensor closes the indoor unit or shuts down the indoor unit is adjusted once every first time according to the formula P = 0.8 P0, and P0 is the current opening degree of the electronic expansion valve; the frequency of the compressor is adjusted according to the formula FK1 = FK0 * (P1 / P0), FK0 is the current frequency, P1 is the capacity of the indoor unit when the temperature sensor is turned on currently, and P0 is the capacity of the indoor unit before the temperature sensor is turned off. The method not only can ensure the reliability of the electronic expansion valve body, but also can solve the problems of vibration sound and pipeline breakage caused by rapid closing / turning-down of the electronic expansion valve.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-connected air conditioners, and specifically to a method for reducing the refrigerant impact force and noise of the electronic expansion valve of a multi-connected air conditioner. Background Art

[0002] The existing multi-connected air conditioner has one outdoor unit connected to multiple indoor units. When the temperature sensor of an indoor unit is closed or the indoor unit is shut down, the electronic expansion valve in the refrigeration condition room will quickly close to 0 steps, and in the heating condition, it will quickly close to the slightly open 30 steps. At this time, due to the rapid closing / narrowing of the electronic expansion valve, a shock wave will be generated, which will generate a certain impact force on the valve body of the electronic expansion valve, affecting its reliability, and may even cause vibration noise and rupture due to the sudden increase in pipeline pressure. Summary of the Invention

[0003] The present invention provides a method for reducing the refrigerant impact force and noise of the electronic expansion valve of a multi-connected air conditioner. This method can not only ensure the reliability of the electronic expansion valve body, but also solve the problems of vibration noise and pipeline rupture caused by the rapid closing / narrowing of the electronic expansion valve.

[0004] To achieve the above object, the present invention provides the following technical solution: A method for reducing the refrigerant impact force and noise of the electronic expansion valve of a multi-connected air conditioner, the method being: when the temperature sensor of an indoor unit of the multi-connected air conditioner is closed or the indoor unit is shut down, the closing time of the electronic expansion valve of the indoor unit is extended and the compressor frequency is adjusted proportionally to reduce the refrigerant impact force and noise.

[0005] Preferably, the method specifically includes: the opening degree of the electronic expansion valve of the temperature sensor closed indoor unit or the shut-down indoor unit is adjusted every first time according to P = 0.8P0, where P0 is the current opening degree of the electronic expansion valve, and the minimum value of P is 50Plus.

[0006] Preferably, when the opening degree P of the electronic expansion valve of the temperature sensor closed indoor unit or the shut-down indoor unit is P ≤ 50Plus, in the refrigeration condition, the system controls the electronic expansion valve to close directly, that is, P = 0, and in the heating condition, the opening degree P of the electronic expansion valve is reduced to 30Plus.

[0007] Preferably, the compressor frequency is adjusted according to FK1 = FK0*(P1 / P0), where FK0 is the current frequency, P1 is the capacity of the indoor unit with the temperature sensor turned on currently, and P0 is the capacity of the indoor unit before the temperature sensor is closed; when the compressor frequency is adjusted to FK1, in refrigeration, the compressor performs PI control according to the target low pressure of 0.75 Mpa, and in heating, the compressor performs PI control according to the target high pressure of 2.75 Mpa.

[0008] Compared with the prior art, the beneficial effects of the present invention are:

[0009] 1. By a specific method of adjusting the opening degree of the indoor electronic expansion valve to extend the closing time, the reliability of the indoor electronic expansion valve is achieved, vibration is reduced, and the usage effect is improved.

[0010] 2. By a specific compressor frequency control method, rapid stability of the refrigerant system and the reliability of the electronic expansion valve are achieved. Specific Embodiment

[0011] In order to clearly and completely describe the objectives, technical solutions of the present invention, and make the advantages more clearly understood, the embodiments of the present invention are further described in detail below. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to explain the embodiments of the present invention, not to limit the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0012] Embodiment

[0013] According to the content of fluid mechanics, the calculation formula for refrigerant impact pressure is as follows:

[0014] △P = ρ × c × v × T / T0

[0015] Where: △P is the refrigerant impact pressure, ρ is the fluid density, c is the propagation speed of the water hammer wave, v is the fluid velocity, T is the refrigerant impact wave phase length T = 2L / c, T0 is the valve closing time, and L is the pipeline length.

[0016] It can be seen from the above formula that when the fluid velocity v decreases and the valve closing time T0 of the valve increases, the water hammer intensity △P will decrease.

[0017] Based on the above principle, this embodiment provides a method for reducing the refrigerant impact force and noise of the electronic expansion valve of a multi-connected air conditioner. The method is as follows: when the temperature sensor of the indoor unit of the multi-connected air conditioner is closed or the indoor unit is shut down, the closing time of the indoor electronic expansion valve is extended and the compressor frequency is controlled to be adjusted proportionally to reduce the refrigerant impact force and noise.

[0018] The method specifically includes: when the temperature sensor closes the indoor unit or shuts down the indoor unit, the opening degree of the electronic expansion valve is adjusted every 5 seconds according to P = 0.8P0, where P0 is the current opening degree of the electronic expansion valve, and the minimum value of P is 50Plus. When the opening degree P of the electronic expansion valve of the temperature sensor closing the indoor unit or shutting down the indoor unit is ≤ 50Plus and in the refrigeration condition, the system controls the electronic expansion valve to close directly, that is, P = 0. In the heating condition, the opening degree P of the electronic expansion valve is reduced to 30Plus.

[0019] The method also includes: the compressor frequency is adjusted according to FK1 = FK0 * (P1 / P0), where FK0 is the current frequency, P1 is the indoor unit capacity enabled by the current temperature sensor, and P0 is the indoor unit capacity before the temperature sensor is closed; when the compressor frequency is adjusted to FK1, during refrigeration, the compressor performs PI control with a target low pressure of 0.75 Mpa, and during heating, the compressor performs PI control with a target high pressure of 2.75 Mpa.

[0020] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for reducing the refrigerant impact force and noise of an electronic expansion valve of a multi-split air conditioner, characterized in that: The method is: when the temperature sensor of the indoor unit of the multi-split air conditioner is closed or the indoor unit is shut down, the refrigerant impact and noise are reduced by extending the closing time of the indoor unit electronic expansion valve and controlling the compressor frequency to adjust proportionally.

2. The method for reducing the refrigerant impact force and noise of the electronic expansion valve of a multi-split air conditioner according to claim 1 is characterized in that: The method specifically includes: the temperature sensor turns off the indoor unit or the electronic expansion valve opening of the indoor unit is adjusted every first time according to P=0.8P0, P0 is the current electronic expansion valve opening, and the minimum value of P is 50Plus.

3. The method for reducing the refrigerant impact force and noise of the electronic expansion valve of a multi-split air conditioner according to claim 2, characterized in that: When the temperature sensor turns off the indoor unit or shuts down the electronic expansion valve opening P≤50Plus, in cooling conditions, the system controls the electronic expansion valve to close directly, that is, P=0. In heating conditions, the electronic expansion valve opening P is reduced to 30Plus.

4. The method for reducing the refrigerant impact force and noise of the electronic expansion valve of a multi-split air conditioner according to claim 1, characterized in that: The compressor frequency is adjusted according to FK1=FK0*(P1 / P0), where FK0 is the current frequency, P1 is the capacity of the indoor unit when the current temperature sensor is turned on, and P0 is the capacity of the indoor unit before the temperature sensor is turned off; when the compressor frequency is adjusted to FK1, the compressor is PI controlled according to the target low pressure of 0.75Mpa during cooling, and the compressor is PI controlled according to the target high pressure of 2.75Mpa during heating.