New type of cold and warm independent dual -gas flow cabinet air conditioner

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Evaluation of thesis value:

This article proposes a design of a new type of independent independent dual -gas -current air conditioning and verify its improvement of room heat in the heating mode. The method has certain novelty, leading and feasibility in the industry.

新型冷暖独立双气流柜式空调

Zou Jianhuang

Zhuhai Gree Electric Co., Ltd.

Summary

新型冷暖独立双气流柜式空调

Abstract

Adopting new air -conditioning air ducts to change the traditional cabinet air -conditioning internal flow field into a cold and warm independent double gas flow field, to realize the air outlet and air outlet, and the upper air outlet to send the wind; The hot air can be sent directly to the knee position of the human body to improve the heat comfort of the human body. The new air duct can reduce the temperature difference between the air supply by 1.5 ° C, effectively improving the uniformity of the indoor temperature field, thereby improving the indoor air quality and achieving the purpose of energy saving.

新型冷暖独立双气流柜式空调

Key words

Keywords

新型冷暖独立双气流柜式空调

Cabinet air conditioner; dual air flow; temperature field; air quality

DOI:

10.19784/J.CNKI.ISSN1672-0172.2022.01.006

0 Preface

With the improvement of people’s living standards, cabinet air conditioners are becoming increasingly popular, and consumers have become higher and higher in the comfort of air conditioning. The air -conditioning airflow tissue is a key factor affecting the comfort of the human body and the energy -saving effect of air -conditioning. Consumers have proposed the comfort requirements of “cold winds without blowing people” and “hot winds” and “hot winds”. The traditional cabinet air conditioner refrigerates and heats in the lower part of the air conditioner, and the upper part of the wind [1] (as shown in Figure 1 a)), but due to the small hot air density and the heat of the air, the heating comfort is relatively compared Poor, the hot air is difficult to send to the position below the knee, it is difficult to meet people’s cold heat comfort requirements for feet hot, and the energy saving effect is poor. In order to improve the problem of poor thermal comfort, according to the different needs of the air flow tissue in different seasons, this article proposes independent cold and warm double gas flow technology under the different needs of the air -conditioning overall size. Cabinet air conditioner, add a downfall in the lower part of the air conditioner, the direction of the upper and lower air outlets can be switched according to the needs of different seasons, and then the air -conditioning air outlet is turned back to the air. Show), the cool breeze in the summer is from top to bottom, forming a waterfall -style refrigeration. When heating, the air -conditioned air inlet is returned to the air, and the air outlet is sent to the hot air (as shown in Figure 1 c), forming a carpet -type air supply, so that the temperature of the entire room is quickly distributed. The hot wind can be sent directly to the knee position below the human body to avoid the problem of cold head hot and cold, and improve the heat comfort of the human body [2]. The warmth effect in winter is particularly obvious, which is beneficial to the health of the human body and has good energy -saving effect.

新型冷暖独立双气流柜式空调

Figure 1 Different air conditioners in and out of wind

1 New technology

In order to improve the thermal comfort of the cabinet air conditioner, the traditional single static air duct is changed to a dynamic dynamic dynamic dynamic air duct to achieve the upper part of the air conditioner in the summer cooling time. The air outlet can be swapped according to the needs of use. Add a snail shell panel to the inside of the air duct 2, upper snail shell 6 and rotating snail plate 10, when the summer refrigeration conditions are closed, the lower snail shell plate 6 is closed, and the position of the rotating snail board is as shown in the figure as shown in the figure. 2 Show on the left, due to the negative pressure of centrifugal air leaf 3, the hot air is inhaled from the lower air outlet 1, and after the centrifugal air leaf 3 of the motor 4 drives, the airflow is collected through the snail shell 5, and then flows to the heat exchanger 7 for the heat exchange device 7 for performed by the heat exchanger 7 for permission. The air and refrigerant heat exchange. After the heat is changed, the cold wind is blown out through the high air outlet 8 to achieve the air cooling of the entire room. When heating in winter, the lower snail shell panel 2 and the upper snail shell 6 are turned on at the same time. The negative pressure of the Ye 3, the cold air is inhaled from the upper air outlet 8, and then flows to the heat exchanger 7 for air and the refrigerant thermal exchange. After the heat exchanges, the hot air is done by the centrifugal air leaf 3 driven by the motor 4. After collecting the airflow, the flow to the low position 1 blows out to achieve the air heat control of the entire room. The upper snail shell 6, the lower snail shell panel 2, and the rotating snail board 10 are driven by three different institutions, respectively. The detailed structure is limited to space, and it is not elaborated here.

新型冷暖独立双气流柜式空调

Fig

2 CFD and thermal comfort experiments

2.1 CFD

For the new type of cabinet air conditioner of the above structure, the CFD heating mode is compared with the traditional cabinet air conditioner [3], and the simulation model and working conditions are consistent with the laboratory size and working conditions. 1: 1: Modeling in size, the entire three-dimensional computing domain is 7 m × width 3 m × height 2.5 m, using a polygonal grid, and the ideal gas cannot be compressed in non-regular settings. , Second -order welcoming the wind difference format, the grid of irrelevant verification, quality flow entrance, and pressure boundary exit. The air conditioning heating operation time is 60 min.

Figure 3 shows the section cloud map of the temperature field. The left side is a traditional air conditioner of the aircup, and the new cabinet air conditioner is on the right. The results of the simulation calculation can be clearly seen: Traditional cabinet air conditioners are in the upper part of the air conditioner because of its heating air outlet. Although the air guides can take the hot air to the bottom, it is low to the air conditioner. The rising airflow makes the airless air from the far ground area from the air conditioner, which makes it difficult for the air temperature in the area to rise, especially the temperature below the knee of the human body is low, the overall temperature field uniformity is poor, and the comfort is poor. The new cabinet air conditioner is in the lower part of the air conditioner due to its heating air outlet, and the air is delivered at a low level. Due to the influence of the air -out kinetic energy, the hot air can blow to the remote end near the ground. The temperature is higher, the temperature field distribution is more uniform, the temperature difference between the height of the human body is reduced, and the thermal comfort is very good.

Figure 3 CFD temperature field comparison

2.2 Thermal comfort experiment

The comfort experiment is performed in an experimental room with a length of 7 m, a width of 3 m, and a height of 2.5 m. The cabinet air conditioner is placed in the middle of the width direction and placed by the YZ wall. Indoor conditions: dry ball temperature is 0 ° C, outdoor working conditions: dry ball temperature -5 ° C; air-conditioning temperature set at 30 ° C, heating capacity is 5800 W.

The indoor temperature is measured by the thermocouple. The thermocouple measurement layout point is: evenly arrange 13 planes in the X direction, evenly arrange 6 planes in the Y direction, and evenly arrange 5 planes in the Z direction [4].

Figure 4 is the section of the temperature field section schematic diagram and the temperature standard ruler. Figure 5 to Figure 9 shows the comparison of the temperature field distribution of 60 minutes in different sections of the traditional air conditioner and the new air conditioner, respectively. The area greater than 0.2 m/s), the left side is a traditional air conditioner, and the right side is a new type of air conditioner. Cloud charts show that the temperature distribution of the new cabinet air conditioner on the right is more uniform than the temperature distribution of the traditional cabinet air conditioner on the left. The temperature difference (the difference between the maximum temperature and the minimum temperature) is reduced by 1.5 ° C. The temperature of the area below the knee of the human body is higher, and there is no obvious low -temperature area like a traditional air conditioner. The advantage of the rapid heating effect is obvious, especially the vertical temperature difference in the height is relatively small. The phenomenon, the heat comfort of the human body is significantly improved.

新型冷暖独立双气流柜式空调

Figure 4 The section of the temperature field section schematic diagram and the temperature standard

Figure 5 Run 60 minutes temperature field, X-Z plane, y = 1.5 m

Figure 6 Run 60 minutes temperature field, x-y plane, z = 0.5 m

Figure 7 Run 60 minutes temperature field, x-y plane, z = 1 m

Figure 8 Run 60 minutes temperature field, x-y plane, z = 1.5 m

Figure 9 Run 60 minutes temperature field, Y-Z plane, x = 1.5 m

新型冷暖独立双气流柜式空调

The middle and upper curve in Figure 10 indicate the upper edge of the wind farm. Compared with the air conditioning heating mode, the new type of cabinet air -conditioning hot breeze is attached to the ground 5 m. Due to the weakened air kinetic energy and the hot air density, the hot air begins to rise. No one’s head (ordinary people are sitting on the stool about 1 m), and only a weak hot wind blows between 4.5 m and 5 m when it is about 1 m. The body of the human body avoids the phenomenon of hot and cold heads of the human body. The warmth effect is particularly obvious, and its heat comfort is very good. The traditional cabinet air conditioner is within 5 m. Due to the high air conditioner’s high air, the wind resistance is directed through the air outlet, and the air resistance is increased, plus the influence of air viscosity and hot air density. After transporting about 2 m, the hot air began to rise to the shoulders and heads of the human body, so that there was no hot air conveying near the ground after 3.5 m, that is, there was no hot air conveying in the area below the knee of the human body. It is difficult to deliver to the part of the human knee, and the problem of severe head heat and feet occurs. Its heat comfort is poor, and the heat rises away from the human body, causing energy waste, and its energy saving is very poor.

Figure 10 The heating mode comparison of the air supply area (X-air supply distance; Z-room height)

2.3 Experimental analysis

According to the temperature collection data of different positions in different positions in the experiment, the temperature of the airflow tissue is evaluated and analyzed by the uneven temperature coefficient. Low, the higher the comfort. Table 1 is a comparison of uneven coefficients in different times in the middle section of different directions. The data shows that the uneven coefficient of the new cabinet air conditioner is reduced by 63%to 73%. The temperature difference between the temperature of the room in the vertical direction and horizontal direction of the room is significantly reduced. The effect is obvious.

Table 1 Temperature uneven coefficient comparison

3 conclusions

新型冷暖独立双气流柜式空调

In response to the industry bottleneck of traditional cabinet air -conditioning comfort, use new air -conditioning airway technology to propose independent cold and warm dual air flow air ducts without increasing the fan. Switching through the air duct mode, new independent warm and warm dual air flow technology, through traditional air conditioning Comparison of simulation and comfort experiments, the following conclusions are obtained:

(1) Cold and warm dual air flow giving mode can even send the hot air to the entire room, which can improve the uniformity of temperature distribution, so that the hot air is sent below the knee of the person, avoiding the hot air blowing to the people’s head to cause discomfort. The heating effect of air conditioning, improve the heat comfort of the air conditioner, and greatly reduce the vertical temperature difference and horizontal temperature difference between the human activity area.

(2) Compared with traditional air conditioners, the temperature of each plane of the room should be increased by 2 to 4 ° C. The temperature difference between the air delivery temperature is 1.5 ° C, and the uniformity is significantly increased by about 70%.

(3) The new type of air delivery technology makes the human body warm and the effect of warmth, preventing the phenomenon of head heat and feet, solve the bottleneck problem of poor thermal comfort of traditional air conditioners, improves indoor air quality, has good application value and market promotion prospects Essence

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新型冷暖独立双气流柜式空调

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新型冷暖独立双气流柜式空调

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(Editor in charge: Zhang Yanrong)