US20070017667A1

US20070017667A1 - Air conditioning system having a terminal chest to provide optimal airflow

Info

Publication number: US20070017667A1
Application number: US11/186,769
Authority: US
Inventors: Kuo-Liang Weng
Original assignee: Cohand Technology Co Ltd
Current assignee: Cohand Technology Co Ltd
Priority date: 2005-07-22
Filing date: 2005-07-22
Publication date: 2007-01-25

Abstract

An air conditioning system having a terminal chest to provide an optimal airflow mainly includes a first adjustable baffle in a return air inlet of each terminal chest that is openable to a desired degree to regulate second time return air volume and a corresponding first time air intake volume according to alterations of air conditioning energy requirement of individual air conditioning area. A variable speed air fan motor is provided that can automatically adjust the rotation speed to deliver optimal airflow volume to automatically balance the air conditioning energy supply with the air conditioning load, thereby to save energy and prevent cool air effect, and maintain a desired air quality.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The invention relates to an air conditioning system that has a terminal chest to provide and deliver an optimal airflow volume for each air conditioning area according to airflow and air conditioning energy requirements.
2. Description of the Prior Art
The conventional air conditioning system has a terminal chest 2 (referring to FIGS. 1 and 2) which delivers heat source (cool air or warm air) provided by a first heat source supply system 1 to one or more air conditioning area AO. The terminal chest 2 of each air conditioning area AO has an air vent 21 which contains an adjustable baffle 211 to control airflow of a first time air intake. An air fan motor 22 sends the air through an air outlet 25 to the air conditioning area AO. The terminal chest 2 has a return air inlet 24 on one side that has a selected cross section to provide a second time return airflow. A setting face panel 23 is provided for setting a set temperature TSo of the air conditioning area AO. There is a temperature sensor B1 to detect the ambient temperature TAo of the air conditioning area AO.
Delivering of airflow in the conventional air conditioning system generally adopts two types, one is Constant Air Volume System (CAV system), another is Variable Air Volume System (VAV system). The main difference between the two is as follow:
The CAV system maintains a constant airflow volume and responds to load variation by changing the temperature of the delivering airflow. The VAV system maintains a constant temperature of the delivering airflow, and responds to load variation by changing the volume of the delivering airflow. For the CAV system to respond the air conditioning load variation, the most simple control approach is to cut off cooling water or direct hot water into a heat exchange tube through a water valve. While this control method is economic and simple, temperature and humidity fluctuate too much in the air conditioning area, and energy control is difficult. It cannot achieve the desired goal. Such an approach cannot meet the requirements of the modern time. To remedy the shortcomings of the CAV system, one way is to open or close the water valve proportionally to adjust the temperature of the delivering airflow. While this approach has some improvements in limiting the fluctuation of the temperature and humidity, the temperature of the piping fluctuates and is difficult to reach an optimal balance point when the volume of cooling and hot water changes. Hence the temperature and humidity in the air conditioning area are difficult to reach a desired condition. Such an approach can be better controlled in the warm air mode. But in the cool air mode with the flowing volume of the cooling water changed, the average effective temperature of the piping also changes. In a low sensible heat loading environment, to reach a desired humidity is difficult to control. On the other hand, the VAV system has improvements on the shortcomings of the CAV systems regarding water claiming, excessive temperature and humidity fluctuations and the like, and can save energy, reduce noise and stabilize the temperature and humidity, and malfunction can be reduced. But in the low loading operation, airflow is not sufficient and air circulation in the air conditioning area is undesirable. In the event of uneven temperature distribution and not adequate external air replenishment, people could feel uncomfortable. The cool air effect could even impair the health of people who are not physically fit.
Because of the conventional VAV and CAV systems cannot meet the requirement of providing a comfortable condition for users, and the air conditioning system controlled manually consumes a lot of energy, they become a big concern in energy conservation.

SUMMARY OF THE INVENTION

In view of the aforesaid problems occurred to the conventional air conditioning systems, the present invention aims to provide an air conditioning system with a terminal chest to provide an optimal airflow. The terminal chest according to the invention has a return air inlet which contains a first adjustable baffle. The first adjustable baffle can be opened to a desired degree according to air conditioning energy requirement alteration of each air conditioning area to regulate the second time return airflow volume, and also regulate the first time air intake volume of the air conditioning. The terminal chest has an air fan motor of variable speed that can be controlled to rotate at a speed to generate an optimal airflow volume according to the required airflow volume in the air conditioning area when the ambient temperature reaches the set temperature. Supply of air conditioning energy of each air conditioning area can also be regulated to achieve an automatic balance with the air conditioning load. When the ambient temperature of each air conditioning area approaches or reaches the set temperature, and the optimal airflow volume is provided, energy can be saved and cool air effect can be prevented, and a desired air conditioning quality can be achieved.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an embodiment of a conventional air conditioning.
FIG. 2 is a schematic view of another embodiment of a conventional air conditioning.
FIG. 3 is a schematic view of an air conditioning embodiment of the invention.
FIG. 4 is a control flow chart-1 of the invention.
FIG. 5 is a control flow chart-2 of the invention.
FIG. 6 is a control flow chart-3 of the invention.
FIG. 7 is a control flow chart-4 of the invention.
FIG. 8 is a control flow chart-5 of the invention.
FIG. 9 is a control flow chart-6 of the invention.
FIG. 10 is a schematic view of a second embodiment of the invention.
FIG. 11 is another schematic view of the second embodiment of the invention.
FIG. 12 is a schematic view of a third embodiment of the invention.
FIG. 13 is a schematic view of a fourth embodiment of the invention.
FIG. 14 is a control flow chart-1 of the fourth embodiment of the invention.
FIG. 15 is a control flow chart-2 of the fourth embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Refer to FIG. 3 for an embodiment of the invention. The air conditioning system includes a first heat source supply system (for cool air or warm air) 3 to provide required air conditioning for one or more air conditioning area A, a terminal chest 4 which has an air vent 41 to send air to the air conditioning area A, and a variable speed air fan motor 42 to deliver first time air-conditioned through an air outlet 45 to the air conditioning area A. The terminal chest 4 has an return air inlet 44 on one side. The return air inlet 44 contains a first adjustable. baffle 441. A face panel 43 is provided for setting a set temperature value TS for the air conditioning area A, and a temperature sensor B2 is provided to detect the ambient temperature TA of the air conditioning area A.
The main features of the invention are as follows: The first adjustable baffle 441 in the return air inlet 44 can be opened and adjusted according to the energy requirement of the air conditioning area A to regulate the first time air intake volume of air conditioning and adjust the cross section area of the return air inlet 44 to control second time return air volume. By regulating according to the energy requirement of air conditioning, the variation of delivering air temperature and returning air temperature can be maintained in the minimum temperature range of the delivering air. The air fan motor 42 in the terminal chest 4 also can be controlled to rotate at a speed to provide an optimal airflow volume according to the airflow requirement of the air conditioning area A when the ambient temperature TA of the air conditioning area A reaches the set temperature Ts. Hence supply of air conditioning energy in the air conditioning area A automatically balances with the air conditioning load. The procedures are as follow (referring to FIGS. 4 and 5):

- 1. Select operation mode (step S1): User selects an air conditioning system operation mode through the setting face panel 43 (step S10, selecting cool air operation mode—step S11, or warm air operation mode—step S12). The step S1 may also be executed through a network link;
- 2. Compare the set temperature value TS with the detected ambient temperature value TA (step S2): Compare the set temperature value TS of the air conditioning area A set through the setting face panel 43 with the ambient temperature TA of the air conditioning area A detected by the temperature sensor B2; and
- 3. Based on the comparison result, control opening degree of the first adjustable baffle 441 in the return air inlet 44 to regulate the first time air intake volume and second time air return volume, and the air fan motor 42 adjusts to a corresponding rotation speed to provide the optimal airflow volume so that supply of air conditioning energy automatically balances with the air conditioning load (step S3). When the ambient temperature TA approaches or reaches the set temperature TS, the airflow volume is maintained at the optimum airflow volume condition (setting of the optimum airflow volume is done according the standards set by American Refrigeration and Air-Conditioning Association, the optimum airflow volume is set according to air exchange requirement of the use environment, and the optimum airflow volume usually is indicated by the minimum operation airflow volume of the air fan motor).
  According to the invention, the first adjustable baffle 441 can be used to regulate the first time and second time air, coupled with the regulated and corresponding rotation speed of the air fan motor 42, an optimum airflow volume can be provided. The procedures are as follow:
A. In the cool air operation mode (step SI 1, referring to FIGS. 5 and 6), the procedures are as follow:
- 1. When TA>TS+X (step S211), namely the ambient temperature TA is greater than the set temperature TS plus a setting variation X, the first adjustable baffle 441 is opened to a minimum returning air condition (the second time return air is minimum), and the first time air intake volume is maximum, and the air fan motor operates at the maximum rotation speed (step S311);
- 2. When T S+X≧T A≧T S (step S212), namely the rotation speed of the air fan motor 42 and ΔT are in direct proportion (ΔT is the temperature difference between TA and TS, namely ΔT=TA−TS) (step S312), opening operation of the first adjustable baffle 441 is as follow (referring to FIG. 7):
  - 2-1. When ΔT>Y (Y is the set value), the first adjustable baffle 441 closes a set air vent displacement Z according the ratio of Y/t (t is the setting time), and comparison and operation are performed anew after elapse of each time unit t;
  - 2-2. When ΔT<−Y, the first adjustable baffle 441 opens a set air vent displacement Z according the ratio of Y/t, and comparison and operation are performed anew after elapse of each time unit t;
  - 2-3. When |ΔT|≦Y, opening of the first adjustable baffle 441 remains unchanged, and comparison and operation are performed anew after elapse of each time unit t;
- 3. When T A<T S (step S213), the first adjustable baffle 441 opens to the maximum, and the first time air intake volume is minimum (step S313), and the rotation speed of the air fan motor 42 is minimum (this minimum value generally is set as the optimal airflow volume value).
B. In the warm air operation mode (step S12, referring to FIGS. 5 and 8):
- 1. When T A <T S−X (step S221), the first adjustable baffle 441 opens to the minimum for return air (second time air return volume is minimum), the first time air intake volume is maximum, and the air fan motor 42 operates at the maximum rotation speed (step S321);
- 2. When T S−X≦T A≦T S (step S222), the rotation speed of the air fan motor 42 is in inverse proportion with ΔT (step S322), opening operation of the first adjustable baffle 441 is as follow (referring to FIG. 9):
  - 2-1. When ΔT<−Y, the first adjustable baffle 441 closes a set air vent displacement Z according the ratio of Y/t, and comparison and operation are performed anew after elapse of each time unit t;
  - 2-2. When ΔT>Y, the first adjustable baffle 441 opens a set air vent displacement Z according the ratio of Y/t, and comparison and operation are performed anew after elapse of each time unit t;
  - 2-3. When |ΔT|≦Y, opening of the first adjustable baffle 441 remains unchanged, and comparison and operation are performed anew after elapse of each time unit t;
- 3. When T A>T S (step S223), the first adjustable baffle 441 opens to the maximum for the return air, the second time return air volume is maximum, while the first time air intake volume is minimum, and the rotation speed of the air fan motor 42 is minimum (step S323).

Refer to FIG. 10 for a second embodiment of the invention. Under the structure of the previous embodiment depicted in FIG. 3, a second heat source supply device 47 (47′) is provided on a rear side or front side of the air fan motor 42 (referring to FIG. 11). This aims to lower the temperature when the temperature of the air delivered by the first heat source supply device 3 is too high (in the warm air supply condition) without reducing first time airflow delivering volume. On the contrary, when the temperature of the air delivered by the first heat source supply device 3 is too low (in the cool air supply condition), the second heat source supply device 47 (47′) can raise the temperature.
Refer to FIG. 12 for a third embodiment of the invention. It aims to prevent too low of humidity in the air conditioning area A. A moisturizer 48 is added in front of the second heat source supply device 47. When the humidity value in the air conditioning area A drops below a set humidity value, the moisturizer 48 is activated.
Refer to FIG. 13 for a fourth embodiment of the invention. It is for a condition in which the first time air of the air conditioning is a VAV system. A first heat source supply system 6 provides required air conditioning (first time air), and a terminal chest 5 has an air vent 51 on the inlet that contains a second adjustable baffle 511. The second adjustable baffle 511 can be opened and adjusted as desired according to energy requirement of the air conditioning area A to control first time airflow volume of the air conditioning intake air. A fan motor 52 is provided to send the first time air to the air conditioning area A2 through an air outlet 55. The terminal chest 5 has a return air inlet 54 which has an adjustable cross section to provide second time return air. A setting face panel 53 is provided to set the temperature TS2 of the air conditioning area A2, and a temperature sensor B3 is provided to detect the ambient temperature TA2 of the air conditioning area A2. The return air inlet 54 has a first adjustable baffle 541 which can be opened and adjusted to a desired degree according to the energy requirement of the air conditioning area A2. Coupled with the second adjustable baffle 511 which can be opened and adjusted, the air conditioning first time air intake volume entering through the air vent 51 can be regulated, and the second time return air volume can be regulated according to energy requirement so that the difference of the air delivering temperature and return air temperature can be maintained in a minimum air delivering temperature range, and an optimal airflow volume is supplied to the air conditioning area A2 to achieve automatic balance between supply of air conditioning energy and air conditioning load. Refer to FIG. 4 for the operation procedures. While the first adjustable baffle 541 can regulate the second time return air volume, the second adjustable baffle 511 can regulate the first time air intake volume, coupled with the adjustable rotation speed of the air fan motor 52, an optimal airflow volume can be provided. The procedures are as follow:
A. In the cool air operation mode (referring to FIG. 14):

- 1. When T A 2 >T S 2 +X (step S214), the first adjustable baffle 541 opens to a minimum return air condition (the second time return air volume is minimum), the second adjustable baffle 511 is fully opened, the first time air intake volume is maximum, and the air fan motor 52 operates at the maximum rotation speed (step S314);
- 2. When T S 2 +X≧T A 2 ≧T S 2 (step S215), the rotation speed of the air fan motor 42 and ΔT are in direct proportion (step S315), opening operation of the first adjustable baffle 541 and the second adjustable baffle 511 is as follow (referring to FIG. 7):
  - 2-1. When ΔT>Y, the first adjustable baffle 541 closes a set air vent displacement Z according the ratio of Y/t, the second adjustable baffle 511 opens a set of corresponding air vent displacement Z, and comparison and operation are performed anew after elapse of each time unit t;
  - 2-2. When ΔT<−Y, the first adjustable baffle 541 opens a set air vent displacement Z according the ratio of Y/t, the second adjustable baffle 511 closes a set of corresponding air vent displacement Z, and comparison and operation are performed anew after elapse of each time unit t;
  - 2-3. When |ΔT|≦Y, opening of the first adjustable baffle 541 and the second adjustable baffle 511 remains unchanged, and comparison and operation are performed anew after elapse of each time unit t;
- 3. When T A 2 <T S 2 (step S216), the first adjustable baffle 541 opens to a maximum return air condition (the second time return air volume is maximum), the second adjustable baffle 511 opens to the minimum, the first time air intake volume is minimum (step S316), and the rotation speed of the air fan motor 52 is minimum.

B. In the warm air operation mode (referring to FIG. 15):

- 1. When T A 2 <T S 2 −X (step S224), the first adjustable baffle 541 opens to a minimum return air condition (second time return air volume is minimum), the second adjustable baffle 511 is fully opened, the first time air intake volume is maximum, and the air fan motor 52 operates at the maximum rotation speed (step S324);
- 2. When T S 2 −X≦T A 2 ≦T S 2 (step S225), the rotation speed of the air fan motor 52 is in inverse proportion with ΔT (step S325), opening operation of the first adjustable baffle 541 and the second adjustable baffle 511 is as follow (referring to FIG. 9):
  - 2-1. When ΔT<−Y, the first adjustable baffle 541 closes a set air vent displacement Z according the ratio of Y/t, the second adjustable baffle 511 opens a set of corresponding air vent displacement Z, and comparison and operation are performed anew after elapse of each time unit t;
  - 2-2. When ΔT>Y, the first adjustable baffle 541 opens a set air vent displacement Z according the ratio of Y/t, the second adjustable baffle 511 closes to a set of corresponding air vent displacement Z, and comparison and operation are performed anew after elapse of each time unit t;
  - 2-3. When |ΔT|≦Y, opening of the first adjustable baffle 541 and the second adjustable baffle 511 remains unchanged, and comparison and operation are performed anew after elapse of each time unit t;
- 3. When T A 2>T S 2 (step S226), the first adjustable baffle 541 opens to the maximum, the second time return air volume is maximum, the second adjustable baffle 511 opens to the minimum, the first time air intake volume is minimum, and the rotation speed of the air fan motor 52 is minimum (step S326).

By means of the control processes and embodiments of the invention set forth above, in the condition of the ambient temperature of the air conditioning area where the terminal chest is located having reached a preset temperature range, the difference between the delivering air temperature and returning air temperature can be maintained in a minimum range, and supply of air conditioning energy can automatically balance with the air conditioning load. When the ambient temperature of the air conditioning area approaches or reaches the set temperature, airflow volume is maintained at the optimal level. Hence the invention can save energy, prevent cool air effect, and maintain a desired air conditioning quality.

Claims

1. An air conditioning system comprising a terminal chest providing an optimal airflow volume having a first heat source supply system providing air conditioning to at least one air conditioning area, the terminal chest having an air vent to receive first time air intake of air conditioning, an air fan motor sending air conditioning air to the air conditioning area through an air outlet, a return air inlet located on side thereof that has an adjustable cross section providing second time return air, a setting face panel setting a set temperature of the air conditioning area, and a temperature sensor detecting the ambient temperature of the air conditioning area;

wherein the return air inlet has a first adjustable baffle openable and adjustable to a desired degree according to energy requirement of the air conditioning area regulating air volume of the first time air intake entering through the air vent and the second time return air, the first adjustable baffle is pivotally connected to the terminal chest and is selectively movable between a first position closing the air vent and a second position closing the return air inlet.

2. The air conditioning system of claim 1, further comprising a second heat source supply device on an air inlet side of the air fan motor.

3. The air conditioning system of claim 2, further comprising a moisturizer on an air outlet side of the second heat source supply device.

4. The air conditioning system of claim 1, further having a second heat source supply device on an air outlet side of the air fan motor.

5. The air conditioning system of claim 4, further having a moisturizer on an air outlet side of the second heat source supply device.

6-9. (canceled)

10. The air conditioning system of claim 1, wherein the air vent has a second adjustable baffle controlling and regulating the first time air intake, the second adjustable baffle regulating first time air intake volume according to the energy requirement.