1、附录 A Abstract: Cooling panels are increasingly used in domestic residential buildings. To provide medium temperature cold water for the cool 吨 panel, and dehumidify the indoor air simultaneously, a new kind of temperature-humidity independent control air-conditioning unit was developed for single re
2、sidential house by utilizing multi-variable technology. First, the supply sir temperature was studied to determine the proper supply air flow rate for the humidity control. Then, the energy consumption of different temperature-humidity independent control systems was studied. The analysis indicates
3、that unity evaporating temperature can be used to handle the mois-tore load and sensible heat load in two evaporators. So the unit scheme was put forward. Two evaporators were used to produce medium temperature water and dry air separately, and electric expansion valves were used to control the refr
4、igerant distribution between the two evaporators. Then, experimental work was carried out to in-vestigate the influence of wmpressor frequency, refrigerant distribution on the dehumidification capacity, energy efficiency and refrigeration capacity. In the end, the paper concludes that both compresso
5、r frequency and refrig-erant distribution can control the dehumidification capacity, but the former influences the EER more than the latter, while the latter influences the refrigeration capacity more than the former. We can find a proper running point at certain sensible and latent cooling load by
6、adjusting both compressor frequency and electric expansionvalve. The energy consumption of this kind of unit was estimated and compared with presentair conditioners, which shows that it can save about 41%cooling energy consumption. In the ventilation standards, the indoor relative humidity was alway
7、s ignored in the past, because if the relative humidity is maintained between 30 % and 70 %， it affects little on peoples thermal oom-fort. In Yangtze River area, the outdoor air humidity is very high in the whole year, so the buildingmoisture load needs to be taken into consideration when designing
8、 the air-conditioning system. Jiang Yi etc. started to study the temperature and humidity control air-rnnditioning system in 1990x.They pointed out that low temperature cold source must 6e provided to remove both sensible latent loads, which is a waste of energy, because sensible load can be removed
9、 by higher tempera- ture cold source. They developed the liquid desiccant dehumidification system to control the humidity and medium temperature cold water refrigerator to control the temperature. However, the liquid desiccant dehumidificationsystems are often too large and expensive for a residenti
10、al house. Thus, to develop a new kind of air-conditioner for the residential building to control the temperature and humidity independently is the very problem that we are facing with and to solve. Radiation panel is a new kind of air conditioning device removing heat through radiation. The watersup
11、ply temperature cannot exceed the indoor dewpoint temperature inof condensation on its surface. However, the water supply temperature is always around 7 Celsius degree, which is much lower than the indoor dew point temperature. Consequentheat exchangers or mixture valves are needed toget medium temp
12、erature cold water ( around 18 Celsins degrees)， which is obviously a waste of energyaccording to the second law of thermodynamics.Thus, producing medium temperature cold water directly is a solution to t he problem. At the same time, dry air is needed to compensate the indoor latent load； otherwise
13、, condensation may happen on the surface of the radiation panel. In this paper, we developed a high efficiency residential air-conditioning unit, which can produce medium temperature cold water and dry air simultaneously to deal with the sensible load and latent load separately. In the cold dehumidi
14、fication, the supply air ishandled by surface air cooler to remove the water vapor in it. The temperature and humidity ratio of thesupply air are both lowered, so that it can handle theentire indoor moisture Toad, while undertake a part ofthe sensible heat load. From the point of view of en-ergy con
15、servation, it is assumed that the air is supplied at dew-point temperature. Under certain indoor moisture load, the supply airflow rate changes with its temperature. If the temperature of the supply air is relatively high, e. g.， 16， its humidity ratio is relatively high, thus, it canlessmoisture of
16、 unitair flow rate, so the supply air flowrate has to be enlarged to meet the dehumidification requiretnent. On the contrary,迁 the supply air temperature is low, less air flow rate is needed tothetore. The supply air flow rate at different supply tempetalure is s)bvm in fig. 1. For the residential b
17、uildings, the outdoor airflow rate is determined by the rate of ventilationiel.Thus, in a residential house, of which the area isfixed, the outdoor air flow rate is constant, while thesupply air flow rate changes according to its temperalure. Consequently, the minimum supply air temper-store can be
18、obtained, because the minimum supplair flow rate is the outdoor air flow rate. From fig.2 and fig. 3, we can find that the minimam supply air temperature decreases with the increase of indoor moisture load. At the same supply aiitemperature, the supply sir flow rate increases with In the application
19、, dedicated outdoor air andoutdoor air plus return air are both frequently used. In the dedicated outdoor air system, the supply airtemperature is relatively low, so its cold source ener-gy efficiency is relatively low, which will decrease thesystem efficiency. But it handles less indoor sensiblehea
20、t load,， the high temperature cold source will undertake more load, which can enhance the systemefficiency. In order to study whether the dedicated outdoor air system or the outdoor a us return air system isefficient, numerical models are established to estimate their performances. The study results
21、 show that if ieturn sir is usedin the supply air to remove the moisture, the energyconsumption is less than the case that only outdoor air is used to remove the moisture. As a result, air banfiling unit should be designed according to the outdoorair plus return air flow rate. Different low temperature cold source and hightemperature cold source can be used to handle the indoor moisture load and sensible heat load. In the tablebelow, the equipments and their required temperatureare listed.
