CN109522662B - Method for calculating mixed air temperature of roof type air conditioner - Google Patents
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Abstract
The method is based on the measured value of the existing roof type air conditioner sensor, and the mixed air temperature of the roof type air conditioner is calculated and monitored by utilizing a modeling method, so that the method plays an important role in fault diagnosis of an air conditioning system, optimization of a control strategy of the air conditioning system and saving of energy consumption of the air conditioner. Compared with the prior art, the invention has the following advantages: experiments show that the method has accurate and stable measurement; (2) The method reduces the requirements on the use, installation and precision of the sensor, does not need to additionally purchase and install the temperature sensor, and saves the purchase, calibration and maintenance cost of instruments compared with the traditional measuring method; (3) The method does not require the measured environment to have balanced temperature distribution, and overcomes the defect that the traditional measuring method cannot accurately measure the temperature of the mixed air on a roof-type unit with a compact structure.
Description
Technical Field
The invention belongs to the field of heating ventilation air conditioning engineering, and particularly relates to a method for calculating the mixed air temperature of a roof type air conditioner.
Background
The roof type air conditioner mixes fresh air and return air according to a certain proportion, then processes the mixed air, and finally sends the processed air into the room. The monitoring of the mixed air temperature is significant: first, the mixed air temperature is an important parameter for predicting the performance of a vapor compression refrigeration cycle, and thus it is widely used in the fault diagnosis of an air conditioning system. And secondly, the temperature of the mixed air plays an important role in optimizing the control of an air conditioning system and saving the energy consumption of the air conditioner. Since the mixed air temperature is either too high or too low, which may increase the energy consumption of the air conditioning system.
The current rooftop air conditioners are generally not equipped with a mixed air temperature measuring instrument. The main reasons are as follows: 1. the roof type air conditioning unit has compact structure. The mixing chamber in which the fresh air and the return air are mixed is small in volume, so that a uniform temperature distribution cannot be generated in the mixing chamber. Therefore, the accurate mixed air temperature is difficult to measure by using a common temperature sensor; 2. installing a thermometer increases the initial capital cost of the rooftop air conditioning unit. Rooftop air conditioning units are inherently inexpensive and air conditioner manufacturers are generally reluctant to install a mixed air temperature sensor.
Disclosure of Invention
The invention aims to fill the defects of the prior art and provides a method for calculating the mixed air temperature of a roof type air conditioner.
A method for calculating the mixed air temperature of a roof type air conditioner comprises the following specific steps:
when the fresh air valve of the air conditioner is at the opening θ, the mixed air temperature MAT may be determined by equation (1):
MAT θ ＝β θ ×OAT+(1-β θ )×RAT (1)
in the formula: MAT θ : when the fresh air valve of the air conditioner is in an opening theta, the temperature of mixed air of the roof type air conditioner is controlled; OAT: the temperature of fresh air; RAT (RAT): the return air temperature; beta is a θ : when the fresh air valve of the air conditioner is in the opening theta, the fresh air ratio of the roof type air conditioner is higher.
To the right of the equation of equation (1), the fresh air ratio β of the rooftop air conditioning system is removed θ Being unknown, the other parameters are known quantities and can be obtained directly from the sensor readings.
Fresh air ratio beta of the roof type air conditioner θ Can be determined by the following method:
step 1: when the roof type air conditioner is in a ventilation state (namely, the refrigerating device and the heater are both closed, and the blower is opened), according to the equations (2 a) and (2 b), respectively calculating a fresh air ratio beta when the fresh air temperature OAT is higher than the return air temperature RAT under the working condition h And the fresh air ratio beta of the fresh air temperature OAT to the return air temperature RAT is lower c ；
In the formula: beta is a h : when the fresh air temperature OAT is higher than the fresh air ratio of the roof type air conditioner under the working condition of the return air temperature RAT; beta is a c : the fresh air ratio of the roof type air conditioner is lower than the fresh air ratio of the roof type air conditioner under the working condition that the fresh air temperature OAT is lower than the return air temperature RAT; SAT: the temperature of the air supply; OAT: the temperature of fresh air; RAT (RAT): the return air temperature; Δ T: the temperature of the blower rises.
In equation (2 a) (2 b), except for the temperature rise of the blower as an unknown quantity, other parameters are known quantities. There is no temperature sensor in the rooftop air conditioning system to directly measure the blower temperature rise. Therefore, the temperature rise of the blower is estimated according to the design air volume and the power of the blower. Based on the estimated blower temperature rise, a value for the blower temperature rise is first assumed, and then this assumed value is adjusted according to the following steps.
Step 2: collecting sensor data of fresh air temperature OAT, return air temperature RAT and supply air temperature SAT at multiple moments, substituting into equations (2 a) and (2 b), and solving a fresh air ratio beta when the fresh air temperature is higher than the return air temperature at different moments h And the fresh air ratio beta of the fresh air to the fresh air with the fresh air temperature lower than the return air temperature c Then, according to the equations (3 a) and (3 b), the calculated (beta) at different time points are respectively compared h ) And (beta) c ) Calculating the average value, and calculating the average value beta of the fresh air ratio when the fresh air valve is at the opening theta and the fresh air temperature is higher than the return air temperature under the working condition by the equation (3 a) h,q (ii) a Calculating the average value beta of the fresh air ratio when the fresh air valve is at the opening theta and the fresh air temperature is lower than the return air temperature according to the equation (3 b) c,θ ：
In the formula: beta is a h,θ : when the fresh air valve is in the opening theta, the fresh air temperature is higher than the return air temperatureAverage value of fresh air ratio under the working condition of temperature; beta is a c,θ : when the fresh air valve is at the opening theta, the fresh air temperature is lower than the average value of the fresh air ratio under the working condition of the return air temperature; beta is a beta h,θ,i : determining the fresh air ratio obtained at n different moments when the fresh air valve is at the opening theta and the fresh air temperature is higher than the return air temperature according to the equation (2 a); beta is a c,θ,i : and (3) determining the fresh air ratio obtained at m different moments when the fresh air valve is at the opening theta and the fresh air temperature is lower than the return air temperature, which is determined by the equation (2 b).
And step 3: calculating beta by equation (4) h,θ And beta c,θ If the relative error is less than or equal to 5%, performing step 4, otherwise, re-determining a temperature rise value delta T of the air feeder, and repeating the steps 1, 2 and 3 in sequence;
in the formula: e: relative error; beta is a h,θ : when the fresh air valve is in the opening theta, the fresh air temperature is higher than the average value of the fresh air ratio under the working condition of the return air temperature, and the average value is determined by the equation (3 a); beta is a c,θ : when the fresh air valve is in the opening theta, the fresh air temperature is lower than the average value of the fresh air ratio under the working condition of the return air temperature, and the average value is determined by an equation (3 b).
And 4, step 4: determining the fresh air ratio beta when the fresh air valve is at the opening theta through an equation (5) θ ：
In the formula: beta is a θ : the fresh air ratio when the fresh air valve is at any opening theta; beta is a beta h,θ : when the fresh air valve is at any opening theta, the fresh air temperature is higher than the average value of the fresh air ratio under the working condition of the return air temperature and is determined by an equation (3 a); beta is a beta c,θ : when the fresh air valve is at any opening theta, the fresh air temperature is lower than the average value of the fresh air ratio under the working condition of the return air temperature, and the average value is determined by an equation (3 b).
The preferred technical scheme of the invention is as follows: the return air temperature in step 1 is a known quantity and is directly obtained from the sensor readings.
The preferred technical scheme of the invention is as follows: in the equations (2 a) and (2 b), the temperature rise assumed value delta T of the air feeder is an assumed value, and the fresh air temperature OAT, the return air temperature RAT and the air supply temperature SAT are known quantities and are directly obtained through the reading of the sensor.
The invention has the beneficial effects that:
the invention relates to a method for calculating the mixed air temperature of a roof type air conditioner, which is based on the measured values (specifically comprising fresh air temperature OAT, return air temperature RAT and supply air temperature SAT) of the existing roof type air conditioner sensor, and calculates and monitors the mixed air temperature of the roof type air conditioner by using a modeling method, thereby saving the cost of installing a mixed air thermometer and solving the problem that the mixed air temperature of the roof type air conditioner is difficult to accurately measure. In addition, compared with the prior art, the invention also has the following advantages: experiments show that the method has accurate and stable measurement; (2) The method reduces the requirements on the use, installation and precision of the sensor, does not need to additionally purchase and install the temperature sensor, and saves the purchase, calibration and maintenance cost of instruments compared with the traditional measuring method; (3) The method does not require the measured environment to have balanced temperature distribution, and overcomes the defect that the traditional measuring method cannot accurately measure the temperature of the mixed air on a roof-type unit with a compact structure.
Drawings
Fig. 1 is a schematic view of a conventional rooftop air conditioning unit system of the prior art.
In the figure: 12-a fresh air valve; 14-a return air valve; 16-an air outlet; 18-a blower; 20-an exhaust fan; 22-a filter; 24-a refrigeration device; 26-a heater; 28-air supply duct; 30-a return air duct; 32-indoor; 34-a mixing chamber; 40-fresh air temperature OAT; 42-return air temperature RAT; 44-supply air temperature SAT.
Detailed Description
For further understanding of the contents, features and effects of the present invention, the following examples are given in conjunction with the accompanying drawings. It should be noted that the present embodiments are illustrative and not restrictive, and the protection scope of the present invention is not limited thereby.
A method for calculating the mixed air temperature of a roof type air conditioner comprises the following specific steps:
when the fresh air valve of the air conditioner is at the opening θ, the mixed air temperature MAT may be determined by equation (1):
MAT θ ＝β θ ×OAT+(1-β θ )×RAT (1)
in the formula: MAT θ : when a fresh air valve (12) of the air conditioner is in an opening theta, the temperature of mixed air of the roof type air conditioner is controlled; OAT: fresh air temperature (40); RAT (RAT): return air temperature (42); beta is a θ : when the fresh air valve of the air conditioner is in the opening theta, the fresh air ratio of the roof type air conditioner is higher than the fresh air ratio of the roof type air conditioner;
fresh air ratio beta of the roof type air conditioner q Can be determined by the following method:
step 1: when the roof type air conditioner is in a normal temperature air supply state, respectively calculating a fresh air ratio beta under the working condition that the fresh air temperature OAT is higher than the return air temperature RAT according to equations (2 a) and (2 b) h And the fresh air ratio beta of the fresh air temperature OAT to the return air temperature RAT is lower c ；
In the formula: beta is a h : the fresh air ratio of the roof type air conditioner under the working condition that the fresh air temperature OAT is higher than the return air temperature RAT; beta is a c : the fresh air ratio of the roof type air conditioner under the working condition that the fresh air temperature OAT is lower than the return air temperature RAT; SAT: the temperature of the air supply; OAT: the temperature of fresh air; RAT (RAT): the temperature of return air; Δ T: the temperature of the blower rises.
In equation (2 a) (2 b) the other parameters are known except for the blower temperature rise, which is unknown. There is no temperature sensor in the rooftop air conditioning system to directly measure the blower temperature rise. Therefore, the temperature rise of the blower is estimated according to the design air volume and the power of the blower. Based on the estimated blower temperature rise, a value for the blower temperature rise is first assumed, and then this assumed value is adjusted according to the following steps.
Step 2: collecting sensor data of fresh air temperature OAT, return air temperature RAT and supply air temperature SAT at multiple moments, substituting into equations (2 a) and (2 b), and solving a fresh air ratio beta when the fresh air temperature is higher than the return air temperature at different moments h And the fresh air ratio beta of the fresh air to the fresh air with the fresh air temperature lower than the return air temperature c Then, according to the equations (3 a), (3 b), respectively, for β h And beta c Calculating the average value, namely calculating the average value beta of the fresh air ratio when the fresh air valve is in the opening q and the fresh air temperature is lower than the return air temperature under the working condition by the equation (3 a) c,q (ii) a Calculating the average value beta of the fresh air ratio when the fresh air valve is in the opening q and the fresh air temperature is lower than the return air temperature according to the equation (3 b) c,q ；
In the formula: beta is a h,q : when the fresh air valve is in the opening q, the fresh air temperature is higher than the average value of the fresh air ratio under the working condition of the return air temperature; beta is a c,θ : when the fresh air valve is at the opening theta, the fresh air temperature is lower than the average value of the fresh air ratio under the working condition of the return air temperature; beta is a beta h,q,i : determining a fresh air ratio at n different moments when the fresh air valve is at the opening q and the fresh air temperature is higher than the return air temperature, which are determined by an equation (2 a); beta is a beta c,q,i : and (3) determining the fresh air ratio obtained at m different moments when the fresh air valve is in the opening q and the fresh air temperature is lower than the return air temperature, which are determined by the equation (2 b).
And 3, step 3: calculating beta by equation (4) h,q And beta c,q If the relative error is less than or equal to 5%, performing step 4, otherwise, re-determining the temperature rise assumed value delta T of the air feeder, and sequentially repeating the steps 1, 2 and 3.
In the formula: e: relative error; beta is a h,θ : when the fresh air valve is in the opening q, the fresh air temperature is higher than the average value of the fresh air ratio under the working condition of the return air temperature and is determined by an equation (3 a); beta is a beta c,q : when the fresh air valve is at the opening theta, the fresh air temperature is lower than the average value of the fresh air ratio under the working condition of the return air temperature, and is determined by an equation (3 b),
and 4, step 4: the fresh air ratio (beta) when the fresh air valve is at the opening (theta) is determined by equation (5) q )：
In the formula: beta is a θ : the fresh air ratio when the fresh air valve is at the opening theta; beta is a h,θ : when the fresh air valve is at the opening theta, the fresh air temperature is higher than the average value of the fresh air ratio under the working condition of the return air temperature, and the average value is determined by an equation (3 a); beta is a beta c,θ : when the fresh air valve is in the opening theta, the fresh air temperature is lower than the average value of the fresh air ratio under the working condition of the return air temperature, and the average value is determined by an equation (3 b).
After the end of step 4, the fresh air ratio (beta) of the roof type air conditioner θ ) It has been determined that the mixed air temperature can be determined by equation (1).
The preferred technical scheme of the invention is as follows: the return air temperature in step 1 is a known quantity and is directly obtained from the sensor readings.
The preferred technical scheme of the invention is as follows: in the equations (2 a) and (2 b), the temperature rise delta T of the air feeder is an assumed value, and the fresh air temperature OAT, the return air temperature RAT and the air supply temperature SAT are all known quantities and are directly obtained through the reading of the sensor.
In addition, it is preferable that the fresh air temperature OAT, the return air temperature RAT, and the supply air temperature SAT are known quantities in the equation of the present invention, and the specific values are measured by conventional sensors in the prior art.
To more clearly describe the specific calculation method of the present invention, an example is provided below:
FIG. 1 is a typical rooftop air conditioning system. Fresh air is controlled by a fresh air valve (12) to enter an air conditioning system, and return air is controlled by a return air valve (14) to enter the air conditioning system indoors. Fresh air and return air are first mixed in a mixing chamber (34), then filtered by a filter (22), treated by a refrigerating device (24) and a heater (26), and sent into a chamber (32) by a blower (18) through a blower pipeline (28). The return air passes through a return air pipeline (30), one part of the return air is mixed with fresh air through a return air valve (14), and the other part of the return air is controlled by an exhaust fan (20) and an exhaust valve (16) and is exhausted to the outside.
As shown in fig. 1, a typical rooftop air conditioning system would include the following sensors: fresh air temperature OAT (40), return air temperature RAT (42) and supply air temperature (44).
The application object of the invention is a roof type air conditioning unit system, which comprises an air volume regulating valve, an air supply pipe, a return air pipe, a fan, a refrigerating device and a heater, wherein 3 conventional sensors in the prior art are ensured to be installed in the system for acquiring collected data, and the conventional sensors are respectively used for monitoring the fresh air temperature OAT (40), the return air temperature RAT (42) and the air supply temperature (44).
The principle of the calculation method mainly comprises the following aspects: (a) Assuming an initial value of temperature rise of a blower, when the roof type air conditioner is in a ventilation state, a fresh air ratio under the condition that the fresh air temperature is higher than the return air temperature and a fresh air ratio under the condition that the fresh air temperature is lower than the return air temperature are respectively calculated. (b) The monitoring data of three conventional temperature sensors of fresh air temperature, return air temperature and supply air temperature at different moments are collected, when a fresh air valve is in a certain opening degree, the fresh air temperature is higher than the fresh air ratio under the condition of the return air temperature and the fresh air temperature is lower than the fresh air ratio under the condition of the return air temperature at different moments are respectively calculated, and the two fresh air ratios at different moments are respectively averaged. (c) And comparing the average value of the fresh air ratio obtained when the fresh air valve is at a certain opening degree and the fresh air ratio obtained when the fresh air temperature is higher than the return air temperature with the average value of the fresh air ratio obtained when the fresh air temperature is lower than the return air temperature. And if the relative error of the fresh air valve and the fresh air valve is less than or equal to 5%, determining that the fresh air ratio when the fresh air valve is at the opening degree is equal to the average value of the fresh air valve and the fresh air valve. (d) If the relative error between the two values is larger than 5%, the assumed blower temperature rise value is adjusted, and the steps (a), (b), (c) and (d) are repeated. If the fan temperature rise exceeds the limit, the cycle is terminated. And (3) calculating the temperature of the mixed air according to the fresh air ratio determined in the step (d) and the monitoring data of three conventional temperature sensors of the fresh air temperature, the return air temperature and the supply air temperature.
Taking a laboratory roof type air conditioner as an example, the specific calculation method is as follows:
step 1: the ceiling air conditioner was assumed to have a blower temperature rise (Δ T) of 0.94 ℃. (there is no temperature sensor in the roof type air conditioner can directly measure the blower temperature rise, the power of the roof type air conditioner is 26.4kW, the blower temperature rise is between 0.6 ℃ and 1.7 ℃ according to experience, we assume an initial value of the blower temperature rise first, and then finely adjust the value in the subsequent steps.)
Step 2: sensor data of the fresh air temperature OAT, the return air temperature RAT and the supply air temperature SAT are collected at a plurality of times when the fresh air valve is at different opening degrees (when the fresh air valve is fully closed, namely the opening degree theta = 0; when the fresh air valve is at the minimum opening degree, namely the opening degree theta = 35%; and when the fresh air valve is fully opened, namely the opening degree theta = 100%), and the collected data are shown in table 1.
The collected data are brought into equations (2 a) and (2 b), and the fresh air ratio beta under the working condition that the fresh air temperature is higher than the return air temperature is solved when the fresh air valve is at different opening degrees at different times h And the fresh air ratio beta of the fresh air to the fresh air with the fresh air temperature lower than the return air temperature c The calculation results are shown in Table 2.
Then, the calculated beta is calculated according to the equations (3 a) and (3 b) h And beta c The average values are calculated separately. Calculating the average value beta of the fresh air ratio when the fresh air valve is at the opening theta and the fresh air temperature is higher than the return air temperature under the working condition by the equation (3 a) h,q (ii) a Calculating the average value beta of the fresh air ratio when the fresh air valve is in the opening q and the fresh air temperature is lower than the return air temperature according to the equation (3 b) c,q . The calculation results are shown in Table 3.
And step 3: fine tuning the assumed value of blower temperature rise delta T until beta h,q And beta c,q Relative error of less than or equal to 5%, if the assumption of blower temperature rise delta TIf the temperature exceeds the limit, the calculation is stopped, and if the temperature exceeds the range, the temperature rise limit value of the blower in the test is between 0.6 and 1.7 ℃. Through calculation, when the assumed value of the temperature rise delta T of the air feeder in the experiment is 0.94 ℃, beta is h,q And beta c,q The relative error is less than or equal to 5 percent, and the requirement is met.
And 4, step 4: the fresh air ratio beta when the fresh air valve is at the opening q is determined by equation (5) q . The calculation results are shown in Table 4.
And 5: fresh air ratio beta when the fresh air valve is at different opening degrees q After determination, the mixed air temperature MAT may be calculated by equation (1). The results of the calculations are shown in Table 5.
And (3) verification: in the roof type air conditioner, the volume of a mixing chamber of fresh air and return air is very small, and balanced temperature distribution cannot be generated in the mixing chamber, so that the temperature MAT of mixed air cannot be directly measured for verification. So we pass the verification of the fresh air ratio beta q The mixed air temperature MAT is verified indirectly. Fresh air ratio beta q The verification method of (2) is as follows: under the condition that the opening theta of the fresh air valve is 35% and 100%, respectively measuring the fresh air volume OA and the air volume SA by using an anemometer, and then calculating the fresh air ratio beta according to the formula (6) θ ：
β θ Measurement = OA/SA (6)
The verification result shows that the fresh air ratio beta is calculated according to the method set forth by the patent of the invention θ Compared with the fresh air ratio calculated by measuring the air volume, the error is less than 5.6 percent (the verification result is shown in a table 6). The fresh air ratio calculated by the method is accurate and reliable. The right side of the equation in the equation (1) is actually measured except for the fresh air ratio, so that the temperature of the mixed air calculated by the method is accurate and reliable.
It will be understood that modifications and variations can be effected by a person skilled in the art in light of the above teachings and that all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.
TABLE 1 data collected
TABLE 2 calculated fresh air ratio
TABLE 3 average value of fresh air ratio under different working conditions
TABLE 4 fresh air ratio beta after temperature rise of the fine-tuning blower θ
Table 5 calculated mixed air temperature MAT
TABLE 6 verification of calculated fresh air ratio
Claims (3)
1. A method for calculating the temperature of mixed air of a roof type air conditioner comprises the following steps:
when the fresh air valve of the air conditioner is at the opening q, the mixed air temperature MAT may be determined by equation (1):
MAT θ ＝β θ ×OAT+(1-β θ )×RAT (1)
in the formula: MAT θ When a fresh air valve of the air conditioner is in an opening theta, the temperature of mixed air of the roof type air conditioner is controlled; OAT: the temperature of fresh air; RAT (RAT): the return air temperature; beta is a θ : when the fresh air valve of the air conditioner is in an opening theta, the fresh air ratio of the roof type air conditioner is adjusted;
to the right of the equation of equation (1), except for the fresh air ratio (β) of the rooftop air conditioning system θ ) The parameter is unknown quantity, and other parameters are known quantities and can be directly obtained from the reading of the sensor;
fresh air ratio (beta) of the roof type air conditioner θ ) Can be determined by the following method:
step 1: when the roof type air conditioner is in a normal temperature air supply state, respectively calculating a fresh air ratio beta when the fresh air temperature (OAT) is higher than the Return Air Temperature (RAT) under the working condition according to equations (2 a) and (2 b) h And the fresh air ratio beta of the fresh air temperature OAT to the fresh air temperature (RAT) under the working condition that the fresh air temperature OAT is lower than the return air temperature c
In the formula: beta is a h : when the fresh air temperature OAT is higher than the fresh air ratio of the roof type air conditioner under the working condition of the return air temperature RAT; beta is a c : the fresh air ratio of the roof type air conditioner under the working condition that the fresh air temperature OAT is lower than the return air temperature RAT;SAT: the temperature of the air supply; OAT: the temperature of fresh air; RAT (RAT): the return air temperature; Δ T: the temperature of the blower rises;
in the equation (2 a) (2 b), except that the temperature rise of the air feeder is unknown, other parameters are known, and no temperature sensor can directly measure the temperature rise of the air feeder in the roof type air conditioning system, so that the temperature rise of the air feeder is estimated according to the design air volume and power of the air feeder, the temperature rise value of one air feeder is assumed according to the estimated temperature rise of the air feeder, and then the assumed value is adjusted according to the following steps;
step 2: collecting sensor data of fresh air temperature OAT, return air temperature RAT and supply air temperature SAT at a plurality of moments, substituting the sensor data into equations (2 a) and (2 b), and solving a fresh air ratio beta when the fresh air temperature is higher than the return air temperature at different moments h And the fresh air ratio beta of the fresh air to the fresh air with the fresh air temperature lower than the return air temperature c Then according to the equations (3 a) and (3 b), respectively calculating the (beta) at different time points h ) And (. Beta.) of c ) Calculating the average value, namely calculating the average value beta of the fresh air ratio when the fresh air valve is at the opening theta and the fresh air temperature is higher than the return air temperature under the working condition by the equation (3 a) h,θ (ii) a Calculating the average value beta of the fresh air ratio when the fresh air valve is at the opening theta and the fresh air temperature is lower than the return air temperature according to the equation (3 b) c,θ ：
In the formula: beta is a h,θ : when the fresh air valve is at the opening theta, the fresh air temperature is higher than the average value of the fresh air ratio under the working condition of the return air temperature; beta is a c,q : when the fresh air valve is in the opening q, the fresh air temperature is lower than the average value of the fresh air ratio under the working condition of the return air temperature; beta is a h,q,i : determining that the fresh air valve is in the opening q and the fresh air temperature is higher than the return air temperature under the working condition of n different moments through the equation (2 a)Obtaining a fresh air ratio; beta is a c,q,i : determining the fresh air ratio at m different moments when the fresh air valve is at the opening q and the fresh air temperature is lower than the return air temperature according to the equation (2 b);
and step 3: calculating beta by equation (4) h,θ And beta c,q If the relative error is less than or equal to 5%, performing step 4, otherwise, re-determining a temperature rise value delta T of the air feeder, and repeating the steps 1, 2 and 3 in sequence;
in the formula: e: relative error; beta is a h,q : when the fresh air valve is in the opening q, the fresh air temperature is higher than the average value of the fresh air ratio under the working condition of the return air temperature and is determined by an equation (3 a); beta is a c,q : when the fresh air valve is in the opening q, the fresh air temperature is lower than the average value of the fresh air ratio under the working condition of the return air temperature, and the average value is determined by an equation (3 b);
and 4, step 4: the fresh air ratio beta when the fresh air valve is at the opening q is determined by equation (5) q ：
In the formula: beta is a θ : the fresh air ratio when the fresh air valve is at any opening q; beta is a beta h,q : when the fresh air valve is at any opening theta, the fresh air temperature is higher than the average value of the fresh air ratio under the working condition of the return air temperature and is determined by an equation (3 a); beta is a c,θ : when the fresh air valve is at any opening theta, the fresh air temperature is lower than the average value of the fresh air ratio under the working condition of the return air temperature, and the average value is determined by the equation (3 b).
2. A method of calculating a temperature of mixed air of a rooftop air conditioner according to claim 1, wherein: the return air temperature in step 1 is a known quantity and is directly obtained from the sensor reading.
3. A method for calculating a temperature of mixed air of a rooftop air conditioner as recited in claim 1, wherein: in the equation (2 a) and (2 b), the temperature rise assumed value delta T of the blower is an assumed value, and the fresh air temperature OAT, the return air temperature RAT and the supply air temperature SAT are known quantities and are directly obtained by the reading of the sensor.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001294028A (en) * | 2000-04-17 | 2001-10-23 | Shimadzu Corp | Air-conditioning system |
| JP2002130768A (en) * | 2000-10-30 | 2002-05-09 | Denso Corp | Fluid-selling system |
| CN101029881A (en) * | 2007-03-23 | 2007-09-05 | 浙江大学 | Method for measuring and controlling assembled air-conditioner dew point |
| CN106989476A (en) * | 2016-05-31 | 2017-07-28 | 深圳达实智能股份有限公司 | Air quantity control method, device and the central air-conditioning of central air-conditioning |
| CN107301276A (en) * | 2017-06-01 | 2017-10-27 | 上海理工大学 | Large space nozzle outlet air supply is layered air-conditioning convective heat shift Load Calculation Method |
| CN107702272A (en) * | 2017-09-15 | 2018-02-16 | 江苏建筑职业技术学院 | The computational methods of the hybrid air handling system of new return air of fixed secondary mixing ratio |
| CN108844195A (en) * | 2018-06-25 | 2018-11-20 | 广州白云山医药集团股份有限公司白云山制药总厂 | A kind of humiture setting value control device and control method |
-
2018
- 2018-11-23 CN CN201811421414.6A patent/CN109522662B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001294028A (en) * | 2000-04-17 | 2001-10-23 | Shimadzu Corp | Air-conditioning system |
| JP2002130768A (en) * | 2000-10-30 | 2002-05-09 | Denso Corp | Fluid-selling system |
| CN101029881A (en) * | 2007-03-23 | 2007-09-05 | 浙江大学 | Method for measuring and controlling assembled air-conditioner dew point |
| CN106989476A (en) * | 2016-05-31 | 2017-07-28 | 深圳达实智能股份有限公司 | Air quantity control method, device and the central air-conditioning of central air-conditioning |
| CN107301276A (en) * | 2017-06-01 | 2017-10-27 | 上海理工大学 | Large space nozzle outlet air supply is layered air-conditioning convective heat shift Load Calculation Method |
| CN107702272A (en) * | 2017-09-15 | 2018-02-16 | 江苏建筑职业技术学院 | The computational methods of the hybrid air handling system of new return air of fixed secondary mixing ratio |
| CN108844195A (en) * | 2018-06-25 | 2018-11-20 | 广州白云山医药集团股份有限公司白云山制药总厂 | A kind of humiture setting value control device and control method |
Non-Patent Citations (1)
| Title |
|---|
| "基于CFD模拟的阅览室空调方案优选";吕洁等;《沈阳工业大学学报》;20180514;全文 * |
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