阅读说明：本技术 一种热泵变频压缩机加卸载控制方法及系统 (Loading and unloading control method and system for heat pump variable frequency compressor ) 是由 赵密升 钟惠安 张勇 于 2020-04-23 设计创作，主要内容包括：本发明公开了一种热泵变频压缩机加卸载控制方法及系统,所述方法包括以下步骤：S1:获取当前回水温度Tn；S2:获取目标水温T,计算水温偏差△T,△T＝Tn-T；S3:获取1分钟前的回水温度Tb,计算回水温度变化率△T’,△T’＝Tn-Tb；S4:读取压缩机频率控制表TABLE,在TABLE中查找由△T’和ΔT定位区间频率值Fi；S5:获取压缩机当前频率值Fn,计算压缩机目标频率F,F＝Fn+Fi；进一步的,所述TABLE为两个维度的表,通过定位△T’和ΔT能够在TABLE定位唯一的区间频率值Fi。本发明热泵变频压缩机加卸载控制方法,引入回水温度变化率以及水温偏差两个维度用于控制压缩机加卸载,根据机组电流的限加载、卸载、停机保护,可使机组能快速满足客户需求的前提下,尽量减少压缩机的频繁加卸载。(The invention discloses a loading and unloading control method and a system for a heat pump variable frequency compressor, wherein the method comprises the following steps: s1, acquiring the current backwater temperature Tn; s2, acquiring a target water temperature T, and calculating a water temperature deviation delta T which is Tn-T; s3, acquiring the backwater temperature Tb before 1 minute, and calculating the backwater temperature change rate delta T' ═ Tn-Tb; s4, reading a compressor frequency control TABLE TABLE, and searching an interval frequency value Fi positioned by delta T' and delta T in the TABLE; s5, acquiring a current frequency value Fn of the compressor, and calculating a target frequency F of the compressor, wherein F is Fn + Fi; further, TABLE is a two-dimensional TABLE, and a unique interval frequency value Fi can be located in TABLE by locating Δ T' and Δ T. According to the method for controlling the loading and unloading of the variable-frequency compressor of the heat pump, two dimensions of the return water temperature change rate and the water temperature deviation are introduced to control the loading and unloading of the compressor, and the frequent loading and unloading of the compressor can be reduced as much as possible on the premise that the unit can quickly meet the requirements of customers according to the limited loading, unloading and shutdown protection of the unit current.)

1. A loading and unloading control method for a heat pump inverter compressor is characterized by comprising the following steps:

s1, acquiring the current backwater temperature Tn;

s2, acquiring a target water temperature T, and calculating a water temperature deviation delta T which is Tn-T;

s3, acquiring the backwater temperature Tb before 1 minute, and calculating the backwater temperature change rate delta T' ═ Tn-Tb;

s4, reading a compressor frequency control TABLE TABLE, and searching an interval frequency value Fi positioned by delta T' and delta T in the TABLE;

and S5, acquiring the current frequency value Fn of the compressor, and calculating the target frequency F of the compressor, wherein F is Fn + Fi.

2. The heat pump inverter compressor loading and unloading control method according to claim 1, wherein the TABLE is a TABLE with two dimensions, and a unique interval frequency value Fi can be located in the TABLE by locating Δ T' and Δ T.

3. The method for controlling loading and unloading of the frequency conversion compressor of the heat pump according to claim 2, wherein the current return water temperature Tn is an average value of real-time return water temperatures within 10s of forward estimation.

4. The heat pump inverter compressor loading and unloading control method according to claim 3, wherein the frequency variation period is 60 s.

5. The heat pump inverter compressor loading and unloading control method according to claim 4, wherein the steps S1 to S5 are re-executed at an interval of 60S.

6. The method for controlling the loading and unloading of the heat pump inverter compressor according to claim 1, wherein the loading or unloading of the compressor is determined according to the positive and negative values of the interval frequency value Fi.

7. A loading and unloading control system of a heat pump variable frequency compressor comprises a controller, a unit heat exchanger, a storage unit and a compressor, and is characterized in that a temperature sensor is arranged at a water inlet of the unit heat exchanger and used for detecting the water inlet temperature of the unit heat exchanger, and the temperature sensor is connected with the controller; the controller comprises a current backwater temperature obtaining module, a water temperature deviation calculating module, a backwater temperature change rate calculating module, an interval frequency value searching module and a target frequency calculating module;

the current backwater temperature acquisition module acquires the current backwater temperature through a temperature sensor;

the water temperature deviation calculation module acquires a target control return water temperature through user interaction or system setting, and calculates the difference between the current return water temperature and the target control return water temperature;

the return water temperature change rate calculation module is used for acquiring the return water temperature before 1 minute and calculating the difference value between the current return water temperature and the return water temperature before 1 minute;

the interval frequency value searching module reads the compressor frequency control table, searches in the compressor frequency control table and determines the interval frequency according to the return water temperature change rate and the water temperature deviation;

the target frequency calculation module is used for acquiring the current frequency value of the compressor and calculating the sum of the current frequency value of the compressor and the interval frequency value, wherein the sum is the target frequency of the compressor.

8. The heat pump inverter press loading and unloading control system of claim 7, wherein the compressor frequency control table is stored in a memory unit, and the controller is connected to the memory unit and has access to the memory unit.

Technical Field

The invention relates to the technical field of heat pumps, in particular to a loading and unloading control method and system for a heat pump variable frequency compressor.

Background

Along with the propulsion of changing coal into electricity in the north, more and more people use the frequency conversion heating machine, to the frequency conversion heating machine, how to make the operation of unit satisfy customer's demand faster, compromise many-sided requirements such as energy-conservation, reliability simultaneously, under this kind of condition, need carry out energy-saving control to the compressor of heating unit. In the current industry, the frequency control of the compressor of the heating unit generally adopts 'table control' or loading and unloading are carried out through the difference value of target water temperature. The table control is to test the maximum frequency of the unit allowed to operate under different environmental temperatures and return water temperatures through a large number of tests, so as to manufacture a parameter table for control; in the other method, the compressor is operated at high frequency as much as possible to improve the heat production and shorten the heating time through the difference value between the actual water temperature and the target water temperature, namely when the temperature difference between the actual water temperature and the target water temperature is larger than a certain value; when the temperature difference between the two is smaller than a certain value, the frequency of the compressor is dynamically adjusted, and in order to ensure that the actual water temperature is within the target temperature range, the operating frequency of the compressor is lower at the moment. However, when the compressor frequency is higher than a certain frequency, the energy efficiency ratio of the heat pump water heater decreases as the compressor frequency increases, and when the frequency is lower than the certain frequency, the energy efficiency ratio of the heat pump water heater decreases as the compressor frequency decreases. Therefore, the reliability of the compressor cannot be ensured by the conventional mode of controlling the frequency of the compressor of the variable-frequency heat pump water heater through the actual water temperature.

To solve this problem, the present invention is hereby proposed.

Disclosure of Invention

The invention aims to provide a loading and unloading control method for a heat pump variable frequency compressor, which can reduce the frequent loading and unloading of the compressor as much as possible on the premise of quickly meeting the requirements of customers.

The purpose of the invention can be realized by the following technical scheme:

a loading and unloading control method for a heat pump inverter compressor comprises the following steps:

s1, acquiring the current backwater temperature Tn;

s2, acquiring a target water temperature T, and calculating a water temperature deviation delta T which is Tn-T;

s3, acquiring the backwater temperature Tb before 1 minute, and calculating the backwater temperature change rate delta T' ═ Tn-Tb;

s4, reading a compressor frequency control TABLE TABLE, and searching an interval frequency value Fi positioned by delta T' and delta T in the TABLE;

and S5, acquiring the current frequency value Fn of the compressor, and calculating the target frequency F of the compressor, wherein F is Fn + Fi.

Further, TABLE is a two-dimensional TABLE, and a unique interval frequency value Fi can be located in TABLE by locating Δ T' and Δ T.

Further, the current backwater temperature Tn is an average value of real-time backwater temperatures within 10s of forward estimation.

Preferably, the frequency change period is 60S, and the steps S1 to S5 are re-executed at an interval of 60S.

Further, the loading or unloading of the compressor is judged according to the positive value and the negative value of the interval frequency value Fi.

The invention also aims to provide a loading and unloading control system of the heat pump inverter compressor, which can realize the control method.

The purpose of the invention can be realized by the following technical scheme:

a loading and unloading control system of a heat pump variable frequency compressor comprises a controller, a unit heat exchanger, a storage unit and a compressor, wherein a water inlet of the unit heat exchanger is provided with a temperature sensor for detecting the water inlet temperature of the unit heat exchanger, and the temperature sensor is connected with the controller; the controller comprises a current backwater temperature obtaining module, a water temperature deviation calculating module, a backwater temperature change rate calculating module, an interval frequency value searching module and a target frequency calculating module;

the current backwater temperature acquisition module acquires the current backwater temperature through a temperature sensor;

the water temperature deviation calculation module acquires a target control return water temperature through user interaction or system setting, and calculates the difference between the current return water temperature and the target control return water temperature;

the return water temperature change rate calculation module is used for acquiring the return water temperature before 1 minute and calculating the difference value between the current return water temperature and the return water temperature before 1 minute;

the interval frequency value searching module reads the compressor frequency control table, searches in the compressor frequency control table and determines the interval frequency according to the return water temperature change rate and the water temperature deviation;

the target frequency calculation module is used for acquiring the current frequency value of the compressor and calculating the sum of the current frequency value of the compressor and the interval frequency value, wherein the sum is the target frequency of the compressor.

Further, the compressor frequency control table is stored in a storage unit, and the controller is connected to the storage unit and has access to the storage unit.

The invention has the beneficial effects that:

according to the method for controlling the loading and unloading of the variable-frequency compressor of the heat pump, two dimensions of the return water temperature change rate and the water temperature deviation are introduced to control the loading and unloading of the compressor, and then the loading, unloading and shutdown protection are carried out according to the current limit of the unit, so that the frequent loading and unloading of the compressor can be reduced as much as possible on the premise that the unit can quickly meet the requirements of customers.

Drawings

The invention will be further described with reference to the accompanying drawings.

FIG. 1 is a flow chart of a loading and unloading control method for a heat pump inverter compressor according to the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.