Q˙ geQ˙ ev  = m˙ 9(h10 − h9) (38)

The enthalpy at point 1 can be calculated by Eq。 (27) with absorber temperature (calculated by Eqs。 (25) and (26)) at the same

pressure as the evaporator。

The solution pump is modeled as an isenthalpic process, then

Tge,o = Tge,i − m˙ where,

Q˙ ge w,geCp

h2 = h1。 At the heat exchanger, the enthalpy h5 can then be calcu- lated as:

m˙ 2h2 + m˙ 4h4  = m˙ 3h3 + m˙ 5h5 (39)

Tge,i  = ˇTst  + ϕTb (22)

Q˙ gen  = Q˙ tl  + Q˙ bl (23)

For a defined solution mass fraction (range of 45 < X < 70% LiBr) and calculated generator temperature, the saturation pressure, P4 and h4 can be calculated from。

At the throttling process, h6 = h5。 The enthalpy h3 can be deter- mined at the solution heat exchanger, and the absorber heat rejection can be calculated as:

Q˙ ab  = m˙ 10h10 + m˙ 6h6 − m˙ 1h1 (40)

All four heat quantities must be satisfy the chiller energy balance equation,  expressed as

Q˙ ge  + Q˙ ev − Q˙ co  − Q˙ ab  = 0 (41)

Fig。 3 summarizes the input and output parameters of the sim-

ulation。 In the system configuration selection and system design, the input parameters were varied to obtain the maximum system

Tsol = ˙B + Tref ˙A (26)

performance。

160 B。 Prasartkaew, S。 Kumar / Energy and Buildings 68 (2014) 156–164

Fig。 3。   The inputs and outputs of the mathematical model。

4。Selection of the best system configuration

To select the best system configuration, the COPsys of the three configurations listed in Section 2 were determined using Eq。 (42), where Q˙ ev is the heat absorption rate at evaporator, GT is solar radiation, Ac is collector area, m˙ BM is biomass consumption rate and LHVBM is biomass heating value。This performance index was determined for four sky conditions using weather data obtained from the meteorological station at the Asian Institute of Technol- ogy, Bangkok, Thailand (latitude of 14。08◦N) as shown in Fig。 4。 The simulation results of COPsys of all system configurations for each sky condition are shown in Fig。 5(a)–(d), respectively (using the input parameters given in Table 1 of  [3])。文献综述

heater) and day time (energized by solar and auxiliary heater), and it yields the highest performance for all sky conditions。 On a clear sky day, the monthly average daily COPsys of Case 1, Case 2 and Case 3 are 0。24, 0。29 and 0。48, respectively。 During the period when the system is solely energized by the auxiliary heater, Case 3 has significantly higher COPsys (0。64) than the others。 In addition, at the end of the day, the COPsys of Case 3 is very higher than the others as the stored heat can serve the chiller heat requirement without external heat source。 Therefore, for these assumptions and conditions, Case 3 is chosen as the best system configuration。 In the following sections, Case 3 will be the only configuration that will be considered。

摘要:本文介绍了一种太阳能生物质混合动力空调系统的设计。在三个可能的整体系统配置 中，首先基于考虑的，是最合适的配置设计。对存储的平板太阳能集热器元件选择的原则、 锅炉生物质气化炉和水-溴化锂吸收系统进行了描述，并阐述了该系统的设计标准。设计是 为了满足一个 4。5 千瓦负荷和至少 0。7 的太阳能辅助热率。在各种大小的太阳能集热器和在 曼谷的天气条件下，模拟表明基于吸收发生器和生物质气化炉的设定点温度，最适合的太阳 能集热器储存罐的尺寸/容量。 关键词：太阳能；吸收；生物量；冷却；气化炉；模拟；混合