WO2019080275A1

WO2019080275A1 - Frequency dynamic optimization and control method for frequency conversion enhanced vapor injection heat-pump water heater

Info

Publication number: WO2019080275A1
Application number: PCT/CN2017/115117
Authority: WO
Inventors: 徐言生; 徐旭雁; 余华明; 张鸣; 张超; 温春华; 翁雁归
Original assignee: 顺德职业技术学院
Priority date: 2017-10-27
Filing date: 2017-12-08
Publication date: 2019-05-02
Also published as: CN107763857A

Abstract

The invention relates to a dynamic optimization and control method of the frequency of a frequency conversion enhanced vapor injection heat-pump water heater. The frequency conversion enhanced vapor injection heat-pump water heater comprises a frequency conversion compressor (1), an exhaust temperature sensor controller (2), a water tank temperature sensor (4), a water tank (5), a condenser (6), an auxiliary electronic expansion valve (7), an economizer (8), a main electronic expansion valve (9), an evaporator (10) and an outdoor temperature sensor (11). The dynamic optimization and control method are characterized in that in the whole operation process of the heat-pump water heater, the work frequency of the frequency conversion compressor (1) is dynamically optimized and adjusted, meanwhile, the opening degrees of the main electronic expansion valve (9) and the auxiliary electronic expansion valve (7) of a refrigeration system are correspondingly controlled, and the total energy consumption in the whole operation process of the heat-pump water heater is minimum. The dynamic optimization and control method have the main beneficial effects that the work frequency of the frequency conversion compressor (1) is dynamically optimized in the whole operation process of the frequency conversion enhanced vapor injection heat-pump water heater, meanwhile, the opening degrees of the main electronic expansion valve (9) and the auxiliary electronic expansion valve (7) are controlled with the optimal energy efficiency ratio as the target, and the total energy consumption in the whole operation process is minimum.

Description

Frequency dynamic optimization and control method of variable frequency jet booster heat pump water heater

Technical field

The invention relates to a heat pump water heater control method, in particular to a frequency optimization and control method for a variable frequency jet heat pump heat pump water heater.

Background technique

Jet augmentation technology is an effective way to solve the heat and energy efficiency ratio of air source heat pump water heaters in low temperature environment. With the development of frequency conversion technology, variable frequency jet heat pump heat pump water heaters have gradually begun to be applied. Since the compressor operating frequency of the variable frequency jet heat pump heat pump has a great influence on the energy efficiency ratio of the heat pump water heater during operation, the Chinese patent document discloses a "frequency adjustment and control method for the variable frequency jet heat pump heat pump water heater", the publication number of which is CN104633942 A, which can dynamically adjust the operating frequency of the inverter compressor according to the user's heat demand and the outdoor temperature of the heat pump water heater and the temperature of the water tank; the basic principle is that the instantaneous energy efficiency ratio of the heat pump water heater is as close as possible to the operation at every moment during the whole operation process. The best energy efficiency ratio, that is, the higher the instantaneous energy efficiency ratio at each moment, the smaller the total energy consumption during the whole operation of the heat pump water heater under the condition of obtaining the same total heating capacity. However, this conclusion is established under the condition that the heat of the heat pump must be equal during the entire operation. In fact, during the operation of the heat pump water heater, the instantaneous heat generation of the heat pump water heater varies greatly due to the change of the operating conditions and the change of the compressor frequency; therefore, the frequency adjustment method of the compressor of the variable frequency jet heat pumping heat pump water heater proposed in the aforementioned patent document It still needs to be optimized, that is, in the process of optimizing the frequency of the compressor of the variable frequency jet heat pump water heater, it is necessary to consider the change of instantaneous heat generation to minimize the total energy consumption of the heat pump water heater during the whole operation process.

Summary of the invention

The object of the present invention is to overcome the deficiencies of the prior art and provide a frequency dynamic optimization and control method for a variable frequency jet heat pump heat pump water heater, which can dynamically adjust the frequency conversion compressor according to the user's heat demand and the outdoor temperature of the heat pump water heater and the temperature of the water tank. The frequency, at the same time adjust the opening of the main electronic expansion valve and the auxiliary electronic expansion valve of the refrigeration system, so that the total energy consumption of the heat pump water heater during the whole operation process is minimized, thereby achieving the purpose of energy saving.

In order to achieve the above object, the present invention is achieved by a frequency dynamic optimization and control method for a variable frequency jet heat pump heat pump, and the variable frequency jet heat pump heat pump includes a compressor, an exhaust temperature sensor, a controller, and a water tank temperature sensor. , water tank, condenser, auxiliary electronic expansion valve, economizer, main electronic expansion valve, evaporator and outdoor temperature sensor; characterized in that: the heat pump water heater dynamically optimizes the working frequency of the compressor during the whole operation process, and at the same time The opening degree of the main electronic expansion valve and the auxiliary electronic expansion valve of the refrigeration system is controlled accordingly, so that the total energy consumption of the heat pump water heater is minimized during operation; the dynamic frequency optimization adjustment method of the working frequency of the compressor and the main electronic expansion valve and the auxiliary electronic expansion valve The opening control method is as follows:

(a) Establish the main electronic expansion valve and auxiliary electronic expansion valve of the refrigeration system with the optimal instantaneous energy efficiency ratio EER as the outdoor temperature T ₁ , the actual temperature T _{2 of the} water tank and the operating frequency f of the compressor are changed. Opening combination table;

(b) establishing a relationship between the instantaneous heat quantity q of the heat pump water heater and the outdoor ambient temperature T ₁ , the actual temperature T _{2 of the} water tank, and the operating frequency f of the compressor. Equation I: q = E (T ₁ , T ₂ , f); According to the relationship I, the expression II of the total heating amount Q in the whole running time t of the heat pump water heater can be obtained:

(c) establishing a relationship between the instantaneous energy consumption p of the heat pump water heater and the outdoor ambient temperature T ₁ , the actual temperature T _{2 of the} water tank, and the operating frequency f of the compressor: III=p=F(T ₁ , T ₂ , f); According to the relationship III, the expression IV of the total energy consumption P in the whole running time t of the heat pump water heater can be obtained:

(d) The user sets the specific time t _{0 of} water and the water temperature T of the water tank. The controller detects the actual temperature T _{2 of the} current water tank and calculates the required total heating capacity Q. The minimum energy consumption P of the heat pump water heater is the minimum. Value, according to Expression II and Expression IV, the relationship between the operating frequency f of the compressor and the running time t during the whole operation is calculated as V:f=F(t), and the heat pump water heater is in the relationship during the whole running time t. V dynamically adjusts the operating frequency f of the compressor;

(e) During operation of the heat pump water heater, the controller dynamically adjusts the main according to the outdoor ambient temperature T ₁ , the actual temperature T _{2 of the} water tank, and the operating frequency f of the compressor according to the opening combination table of the main electronic expansion valve and the auxiliary electronic expansion valve. The opening of the electronic expansion valve and the auxiliary electronic expansion valve.

In the technical solution, in the whole operation process of the heat pump water heater, the relationship V is simplified to obtain a simplified adjustment method of the working frequency of the temperature-segmented and non-continuous compressor, and the specific method is as follows:

(a) Set the operating frequency of the compressor f: According to the difference between the set water temperature T and the initial water temperature T ₀ of the water tank, the temperature rising process is divided into n segments, n ≥ 2, and each temperature rise range is 2-15 ° C. Rise to 5 ° C, the compressor uses a different operating frequency f _i in each temperature rise section;

(b) According to the temperature rise segmentation of the water tank, the frequency f _{i of} each temperature rise section is distributed by the arithmetic progression, and the calculation formula VI of each temperature rise section frequency f _i is obtained: f _i =f _g -(f _g -f _d (i-1)/(n-1), in formula VI, f _g is the highest frequency value of the compressor during the whole operation; f _d is the lowest frequency value of the compressor during the whole operation; i indicates the initial heating Start the corresponding heating section, i=1, 2,...,n;

(c) The controller detects the outdoor ambient temperature T ₁ , the current actual water temperature T _{2 of the} water tank, the specific time t ₀ at which the user sets the water, and the set water temperature T of the water tank, and sets the lowest frequency f _d of the compressor. The initial value is 30 Hz, and the initial value of the highest frequency f _g of the compressor 1 is 80 Hz;

(d) The controller calculates the time t _s between the current time and the specific water use time t ₀ set by the user, and calculates the water temperature of the water tank to reach the set temperature T according to the expression II, the expression IV and the calculation formula VI. The required time t _j , such as |t _s -t _j | ≤ 5min, indicates that the operating frequency of each temperature rise compressor is set properly and the compressor starts to work; if t _s -t _j ≥5min, the compressor will be The maximum frequency f _{g is} calculated again by 1 Hz every time until |t _s -t _j | ≤ 5min is satisfied. If the requirement is still not met when f _{g is} reduced to 30 Hz, the time at which the compressor starts to start is delayed, and the delay time is calculated by compression. The machine is always calculated by running at 30Hz; if t _s -t _j ≤-5min, the compressor minimum frequency f _d is increased by 1Hz each time until it reaches |t _s -t _j |≤5min, as f _d increases At 80 Hz, the requirements are still not met. The heat pump water heater maintains a fixed frequency during the whole operation. It will be calculated again on the basis of 80 Hz and increased by 1 Hz each time until the requirements are met. If the calculated operating frequency of the compressor is greater than that of the heat pump water heater Set the operating limit of the compressor Frequency, upper frequency is generally protected 100Hz, the compressor is protected by the upper frequency operation;

In the present technical solution, the operating frequency f _i of each temperature rise section of the water tank can be simplified by the quadratic curve f _i =ai ² +bi+c.

In the present technical solution, the initial value of the lowest frequency f _d of the compressor ranges from 10 to 40 Hz, and the initial value of the highest frequency f _g of the compressor ranges from 60 to 100 Hz.

In the technical solution, the compressor is an AC variable frequency compressor or a DC variable speed compressor.

Compared with the prior art, the main advantage of the invention is that the variable frequency jet heat pump heat pump water heater dynamically optimizes the working frequency of the compressor during the whole operation process, and simultaneously opens the main and auxiliary electronic expansion valve with the optimal energy efficiency ratio as the target. Control is performed to minimize the total energy consumption throughout the operation.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of a variable frequency jet heat pumping heat pump water heater system according to the present invention.

Specific embodiment 1

Embodiments of the invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are intended to be illustrative of the invention and are not to be construed as limiting.

The variable frequency jet heat pump heat pump water heater includes an inverter compressor 1, an exhaust temperature sensor 2, a controller 3, a water tank temperature sensor 4, a water storage tank 5, a condenser 6, a auxiliary electronic expansion valve 7, an economizer 8, and a main electronic expansion valve 9. The evaporator 10 and the outdoor temperature sensor 11.

The dynamic frequency optimization adjustment method of the compressor 1 of the heat pump water heater and the opening degree control method of the main electronic expansion valve 9 and the auxiliary electronic expansion valve 7 of the refrigeration system are as follows:

(a) establishing with the heat pump water heater outdoor ambient temperature T _1, the actual temperature of the water tank 5 and T ₂ of the compressor 1 changes the operating frequency f, the main electronic expansion valve of a refrigeration system energy efficiency ratio (EER) optimum instantaneous target and secondary electrons 9 Opening degree combination table of expansion valve 7;

(b) Establish a relationship between the instantaneous heating amount q of the heat pump water heater and the outdoor ambient temperature T ₁ , the actual temperature T _{2 of the} water tank 5, and the operating frequency f of the compressor 1. Equation I: q = E (T ₁ , T ₂ , f According to the relationship I, the expression II of the total calorific value Q in the whole running time t of the heat pump water heater can be obtained:

(c) establishing a relationship between the instantaneous energy consumption p _{i of the} heat pump water heater and the outdoor ambient temperature T ₁ , the actual temperature T _{2 of the} water tank 5, and the operating frequency f of the compressor 1 of the formula III: p = F (T ₁ , T ₂ , f); according to the relationship III, the expression IV of the total energy consumption P in the whole running time t of the heat pump water heater can be obtained:

(d) The user sets the specific time t _{0 of the} water and the water temperature T of the water tank, and the heat pump water heater controller 3 detects the actual temperature T _{2 of the} current water tank 5, and calculates the total total heating amount Q required to calculate the total energy consumption of the entire operation process of the heat pump water heater. P is the minimum target value, and the relationship between the operating frequency f of the compressor 1 and the running time t during the whole operation is calculated according to Expression II and Expression IV. V: f=F(t), the heat pump water heater is in the whole running process. In the relationship V dynamically adjusts the operating frequency f of the compressor 1;

(e) During operation of the heat pump water heater, the controller 3 according to the outdoor ambient temperature T ₁ , the actual temperature T _{2 of the} water tank 5 and the operating frequency f of the compressor 1, according to the main electronic expansion valve 9 and the auxiliary electronic expansion valve 7 of the refrigeration system The opening degree combination table a dynamically adjusts the opening degrees of the main electronic expansion valve 9 and the auxiliary electronic expansion valve 7.

In the present embodiment, during the entire operation of the heat pump water heater, the relationship V is simplified to obtain a simplified temperature and non-continuous compressor 1 operating frequency simplified adjustment method, and the main electronic expansion valve of the refrigeration system 9 And the opening degree of the auxiliary electronic expansion valve 7 is controlled accordingly, and the specific method is as follows:

(a) Set the operating frequency f of the compressor 1 according to the difference between the set water temperature T and the initial water temperature T ₀ of the heat pump water tank 5, and divide the heating process into n segments, n≥2, and each temperature rise range is 2- 15 ° C, preferably the temperature rise is 5 ° C, in each temperature rise section compressor 1 uses a different operating frequency f _i ;

(b) According to the temperature rise segmentation of the water tank 5, the frequency f _{i of} each temperature rise section is distributed by the arithmetic progression, and the calculation formula VI of each temperature rise section frequency f _i is obtained: f _i =f _g -(f _g -f _d ) (i-1) / (n-1), in formula VI, f _g is the highest frequency value of compressor 1 during the whole operation; f _d is the lowest frequency value of compressor 1 during the whole operation; i Indicates the respective temperature rising sections corresponding to the initial heating, i=1, 2, . . . , n;

(c) The controller 3 detects the outdoor ambient temperature T ₁ , the current water temperature T _{2 of the} water tank 5, the specific water time t ₀ set by the user, and the set water temperature T of the water tank 5, and sets the lowest frequency of the compressor 1. The initial value of f _d is 30 Hz, and the initial value of the highest frequency f _g of the compressor 1 is 80 Hz;

(d) The controller 3 calculates the time t _s between the current time and the specific water time t ₀ set by the user, and calculates the water temperature of the water tank 5 to reach the set temperature T according to the expression II, the expression IV and the calculation formula VI. The running time t _j , such as |t _s -t _j | ≤ 5min, indicates that the operating frequency of the compressor 1 of each temperature rise section is set properly, and the compressor 1 starts to work; if t _s -t _j ≥5min, The maximum frequency f _{g of the} compressor 1 is calculated again by 1 Hz every time until |t _s -t _j | ≤ 5 min is satisfied, and if the requirement is still not met when the f _{g is} reduced to 30 Hz, the time at which the heat pump water heater 1 starts to start is delayed. The delay time is calculated by the compressor 1 always running at 30Hz; if t _s -t _j ≤-5min, the lowest frequency f _{d of the} compressor 1 is increased by 1Hz each time until the |t _{s is} satisfied. t _j | ≤ 5min, if the f _{d is} increased to 80Hz, the requirement is still not met. The heat pump water heater maintains a fixed frequency during the whole operation, and will be calculated again on the basis of 80Hz, and then increased by 1Hz each time until the requirement is met; The obtained compressor 1 has a working frequency greater than that set by the heat pump water heater. The upper limit protection frequency of the machine 1 is generally 100 Hz, and the compressor 1 operates at the upper limit protection frequency;

(e) During operation of the heat pump water heater, the heat pump water heater controller 3 expands according to the outdoor ambient temperature T ₁ , the actual temperature T _{2 of the} water tank 5, and the operating frequency f of the compressor 1, according to the main electronic expansion valve 9 and auxiliary electron expansion of the refrigeration system. The opening degree combination table a of the valve 7 dynamically adjusts the opening degrees of the main electronic expansion valve 9 and the auxiliary electronic expansion valve 7.

In the present embodiment, the operating frequency f _i of the temperature rise section compressor 1 of the water tank 5 can be simplified by the quadratic curve f _i = ai ² + bi + c for the relational expression V.

In the present embodiment, the initial value of the lowest frequency f _d of the compressor 1 ranges from 10 to 40 Hz, and the initial value of the highest frequency f _g of the compressor 1 ranges from 60 to 100 Hz.

In the embodiment, the compressor 1 is an AC variable frequency compressor or a DC variable speed compressor.

While the embodiments of the present invention have been shown and described, the embodiments of the invention The scope of the invention is defined by the claims and their equivalents.

Claims

A frequency dynamic optimization and control method for a variable frequency jet heat pump heat pump water heater, the variable frequency jet heat pump heat pump water heater comprises a compressor (1), an exhaust temperature sensor (2), a controller (3), a water tank temperature sensor (4), a water tank (5), condenser (6), auxiliary electronic expansion valve (7), economizer (8), main electronic expansion valve (9), evaporator (10) and outdoor temperature sensor (11); characterized by: heat pump During the whole operation of the water heater, the operating frequency of the compressor (1) is dynamically optimized and adjusted, and the opening of the main electronic expansion valve (9) and the auxiliary electronic expansion valve (7) of the refrigeration system is controlled accordingly to make the heat pump water heater The total energy consumption of the whole operation process is minimum; the dynamic optimization adjustment method of the working frequency of the compressor (1) and the opening control method of the main electronic expansion valve (9) and the auxiliary electronic expansion valve (7) are as follows:

Establish the main electronic expansion valve of the refrigeration system with the optimal instantaneous energy efficiency ratio EER as the heat pump water heater changes with the outdoor ambient temperature T 1 , the actual temperature T 2 of the water tank (5) and the operating frequency f of the compressor (1). And the auxiliary opening table (a) of the auxiliary electronic expansion valve (7);

Establish a relationship between the instantaneous heat quantity q of the heat pump water heater and the outdoor ambient temperature T 1 , the actual temperature T 2 of the water tank (5), and the operating frequency f of the compressor (1). Equation I: q = E (T 1 , T 2 , f); according to the relationship I can obtain the expression II of the total heating capacity Q of the heat pump water heater during the whole running time t:

Establish a relationship between the instantaneous energy consumption p of the heat pump water heater and the outdoor ambient temperature T 1 , the actual temperature T 2 of the water tank (5), and the operating frequency f of the compressor (1). Equation III: p=F(T 1 , T 2 , f); according to the relationship III, the expression IV of the total energy consumption P in the whole running time t of the heat pump water heater can be obtained:

The user sets the specific time t 0 of water and the water temperature T of the water tank. The controller (3) detects the actual temperature T 2 of the current water tank (5), calculates the required total heating capacity Q, and uses the total energy consumption of the heat pump water heater throughout the running process. The minimum value as the target value is calculated according to Expression II and Expression IV. The relationship between the operating frequency f of the compressor (1) and the running time t during the whole operation is V: f=F(t), and the heat pump water heater is running throughout. During the process, the operating frequency f of the compressor (1) is dynamically adjusted according to the relationship V;

During operation of the heat pump water heater, the controller (3) expands according to the outdoor ambient temperature T 1 , the actual temperature T 2 of the water tank (5), and the operating frequency f of the compressor (1) according to the main electronic expansion valve (9) and auxiliary electron expansion. The opening degree combination table (a) of the valve (7) dynamically adjusts the opening degrees of the main electronic expansion valve (9) and the auxiliary electronic expansion valve (7).
The frequency dynamic optimization and control method for a variable frequency jet heat pumping heat pump water heater according to claim 1, characterized in that in the whole operation process of the heat pump water heater, the relationship V is simplified to obtain a temperature-divided, non-continuous compressor ( 1) The working frequency is simplified and the adjustment method is as follows:

(a) Set the operating frequency of the compressor (1) f: According to the difference between the set water temperature T and the initial water temperature T 0 of the water tank (5), the heating process is divided into n segments, n ≥ 2, and each temperature rise range is 2-15 ° C preferably temperature rise is 5 ° C, in each temperature rise section compressor (1) uses a different operating frequency f i ;

(b) According to the temperature rise segmentation of the water tank (5), the frequency f i of each temperature rise section is distributed by the arithmetic progression, and the calculation formula VI of each temperature rise section frequency f i is obtained: f i =f g -(f g -f d )(i-1)/(n-1), in formula VI, f g is the highest frequency value of the compressor (1) during the whole operation; f d is the compressor (1) during the whole operation The lowest frequency value; i represents the respective heating range corresponding to the initial heating, i = 1, 2, ..., n;

(c) The controller (3) detects the outdoor ambient temperature T 1 , the current actual water temperature T 2 of the water tank (5), the specific time t 0 at which the user sets the water, and the water temperature T of the set water tank (5), and sets The initial value of the lowest frequency f d of the fixed compressor (1) is 30 Hz, and the initial value of the highest frequency f g of the compressor (1) is 80 Hz;

(d) The controller (3) calculates the time t s between the current time and the specific water time t 0 set by the user, and calculates the water temperature of the water tank (5) according to Expression II, Expression IV and Calculation Formula VI. Set the time T j required for the temperature T operation, such as |t s -t j | ≤ 5min, indicating that the operating frequency of each temperature rise compressor (1) is set properly, and the compressor (1) starts to work; for example, t s -t j ≥5min, then calculate the maximum frequency f g of the compressor (1) by 1Hz every time until it reaches |t s -t j | ≤ 5min, if the requirement is not met when f g drops to 30Hz, then Delayed compressor (1) start time, its delay time calculation is calculated according to the compressor (1) always running at 30Hz frequency; if t s -t j ≤-5min, the lowest frequency f of the compressor (1) d is calculated again by increasing 1Hz every time until |t s -t j | ≤ 5min is satisfied. If the f d is increased to 80Hz, the requirement is still not met. The heat pump water heater maintains a fixed frequency during the whole operation, which will be based on 80Hz. Recalculate each time by 1 Hz until the requirements are met; if the calculated compressor (1) has a working frequency greater than the set pressure of the heat pump water heater The upper limit protection frequency of the reducer (1), the upper limit protection frequency is generally 100 Hz, and the compressor (1) operates according to the upper limit protection frequency;

(e) During operation of the heat pump water heater, the controller (3) according to the outdoor ambient temperature T 1 , the actual temperature T 2 of the water tank (5), and the operating frequency f of the compressor (1), according to the main electronic expansion valve (9) and The opening degree combination table (a) of the auxiliary electronic expansion valve (7) dynamically adjusts the opening degrees of the main electronic expansion valve (9) and the auxiliary electronic expansion valve (7).
The frequency dynamic optimization and control method for a variable frequency jet heat pumping heat pump water heater according to claim 2, characterized in that the operating frequency f i of each temperature rising section compressor (1) of the water tank (5) can be compared with the relational formula V The secondary curve f i = ai 2 + bi + c is simplified.
The frequency dynamic optimization and control method for a variable frequency jet heat pump heat pump according to claim 1, 2, 3, characterized in that the initial value of the lowest frequency f d of the compressor (1) is in the range of 10-40 Hz, the compressor ( The initial value of the highest frequency f g of 1) ranges from 60 to 100 Hz.
The frequency dynamic optimization and control method for a variable frequency jet heat pumping heat pump water heater according to claim 1, 2, 3, characterized in that the compressor (1) is an AC variable frequency compressor or a DC speed regulating compressor.