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Control Method of Electronic Expansion Valve in Frequency Conversion Heat Pump Water Heater System

A technology of electronic expansion valve and heat pump water heater, which is applied in the direction of fluid heater, lighting and heating equipment, etc., can solve the problems of electronic expansion valve adjustment deviation, lagging compressor frequency change, etc. slow effect

Active Publication Date: 2019-07-23
QINGDAO ECONOMIC & TECHN DEV ZONE HAIER WATER HEATER +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the result measured by the sensor package is not the real temperature, which leads to a deviation in the adjustment of the electronic expansion valve, which will also obviously lag behind the change of the compressor frequency

Method used

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  • Control Method of Electronic Expansion Valve in Frequency Conversion Heat Pump Water Heater System
  • Control Method of Electronic Expansion Valve in Frequency Conversion Heat Pump Water Heater System
  • Control Method of Electronic Expansion Valve in Frequency Conversion Heat Pump Water Heater System

Examples

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Effect test

Embodiment 1

[0038] The preferred embodiment discloses a method for controlling an electronic expansion valve in a frequency conversion heat pump water heater system. Such as figure 1 As shown, the control method includes the following steps:

[0039] Step 1. Calculate the heating capacity Q of the unit when the frequency of the compressor is adjusted to f. Specifically, the heating capacity Q of the unit is calculated by formula 1:

[0040] Formula 1

[0041] Among them, f 0 It is the frequency of the compressor at a certain moment, or the frequency at the current moment, and this value can be automatically measured in the system; Q 0 is the compressor frequency f 0 c is the specific volume of water, which is a constant of 4.187kj / kg °C; V is the volume of water in the water tank, in liters; ΔT is the temperature difference of heating water, in °C, and this value can The sensor detects; t is the hot water heating time when the water temperature rises by ΔT, and the unit is second...

Embodiment 2

[0061] The preferred embodiment discloses a method for controlling an electronic expansion valve in a frequency conversion heat pump water heater system. Same as the preferred embodiment one, the control method includes the following steps:

[0062] Step 1. When the frequency of the compressor is adjusted to f, the heating capacity Q of the unit is calculated;

[0063] Step 2. Calculate the circulating refrigerant mass flow m of the unit according to the heating capacity Q of the unit;

[0064] Step 3. Calculate the circulation area S according to the mass flow m of the circulating refrigerant of the unit;

[0065] Step 4: Calculate the number of steps K of the electronic expansion valve according to the flow area S, and the control device adjusts the number of steps of the electronic expansion valve to K.

[0066] The difference is that step 1 is not limited to using formula 1 to calculate the heating capacity Q of the unit. In the current technology, any method can be used...

Embodiment 3

[0068] This preferred embodiment discloses a control method of an electronic expansion valve in a frequency conversion heat pump water heater system. The control method is to adjust the number of steps K of the electronic expansion valve according to the frequency f of the compressor. The specific steps of the control method are not limited, and the steps K of the electronic expansion valve can be calculated according to the frequency f of the compressor by using an existing formula.

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Abstract

The invention discloses a method for controlling electronic expansion valves in variable-frequency heat-pump water heater systems, and belongs to the field of control on electronic expansion valves. The method is designed for solving problems that existing electronic expansion valves controlled by the aid of existing methods obviously lag behind change of frequencies of compressors and the like. The method for controlling the electronic expansion valves in the variable-frequency heat-pump water heater systems includes adjusting step numbers K of the electronic expansion valves according to frequencies f of compressors. The method for controlling the electronic expansion valves in the variable-frequency heat-pump water heater systems has the advantages that the step numbers K of the electronic expansion valves can be directly adjusted, accordingly, the electronic expansion valves are high in response speed, and the problems of low response speed, response lag, poor precision and the like of the existing electronic expansion valves in the prior art can be solved.

Description

technical field [0001] The invention relates to a control method of an electronic expansion valve in a frequency conversion heat pump water heater system. Background technique [0002] In the frequency conversion heat pump water heater system, the electronic expansion valve is usually used to control the flow of refrigerant. When the frequency of the compressor changes, the flow of refrigerant needs to change accordingly. Existing methods for controlling the electronic expansion valve mainly include the exhaust superheat method and the suction superheat method. [0003] 1. The exhaust superheat method is to measure and calculate the superheat value at the outlet of the evaporator, and adjust the opening degree of the electronic expansion valve according to the superheat value. This method is more based on experience, resulting in poor accuracy; and the adjustment of the electronic expansion valve obviously lags behind the change of the compressor frequency, which is prone t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): F24H4/02F24H9/20
Inventor 黄娟
Owner QINGDAO ECONOMIC & TECHN DEV ZONE HAIER WATER HEATER