**4. Results and discussion of the experiment**

#### **4.1. Experimental results and discussion of ejector**

**1.** The volume distribution of refrigerant liquid phase in the same type of capillary tube:

throttling of the other four capillary tubes is uniformly expressed in **Table 2**.

2 44 0 1 1500 0.64

3 44 −1500 1 0 0.634

4 44 −1400 1 0 0.654

5 44 −1300 1 0 0.68

**Max position (mm)**

**Number of capillaries**

86 Desalination and Water Treatment

**Temperature (°C)**

In order to study the effect of the cooling degree on the volume fraction of the liquid phase of the capillary export refrigerant, this simulation simulated the distribution of the liquid phase of the refrigerant under five degrees of supercooling for each type of capillary. In this system, before throttlinh the refrigerant saturation temperature is 47°C. And every 3°C, select a temperature value for degree of supercooling and the selected temperatures arerespectively 44, 41, 38, 35, 32, as shown in **Figures 5**. And we only focus on the experiment diagram of capillary No. 1, and the phase volume fraction distribution of refrigerant in the process of capillary

According to the results of comprehensive simulation analysis, the volume fraction of the liquid phase of the liquid phase of the five types of capillary tubes shows the trend

> **Max position with its volume fraction**

**Min position (mm)**

**Min position with its volume fraction (liquid)**

**(liquid)**

 0 1 1500 0.646 0 1 1500 0.659 0 1 1500 0.706 0 1 1500 0.732

 −1500 1 0 0.649 −1500 1 0 0.627 −1500 1 0 0.695 −1500 1 0 0.722

 −1400 1 0 0.669 −1400 1 0 0.696 −1400 1 0 0.72 −1400 1 0 0.745

 −1300 1 0 0.695 −1300 1 0 0.723 −1300 1 0 0.739 −1300 1 0 0.769

**Table 2.** The maximum and minimum position with their volume fractions of other capillaries at different temperatures.

A set of experimental transposition was designed to verify the possibility of producing distilled water by the ejector. The main equipment include compressor (2R11B225A), pump (DP-35), condensation absorber (diameter 100 mm and height 300 mm), water generator (diameter 100 mm and height 300 mm), and capillary (length of 400 mm and diameter 2 mm). The above three kinds of forms of ejector were tested. Ejector C failed to form steam ejector function, so **Figure 6** shows throat pressure of the ejectors (A) and (B) versus time.

From **Figure 6**, it can be seen that the minimum pressure of ejector A can reach −0.085 Pa, the corresponding water vapor generator temperature at 50°C, and it can produce very good water vapor ejector effect, meeting the temperature requirements of the condenser of the refrigeration system. The lowest pressure can reach −0.034 Pa, the corresponding water vapor generator temperature at 73°C, but at this temperature, the efficiency of the refrigeration system will be very low. **Figure 8** is the fluid state of the ejector in the experiments.

From **Figure 7**, it can be seen that there is a mixed fluid of water and vapor in the ejectors A and B, while the ejector C produces the backflow, which cannot form an effective water vapor ejector effect. The ejector A is selected as a system unit, and the three different powers of the compressor were used in the production of distilled water. **Table 3** is the amount of distilled water produced by three experiments.

**Figure 6.** Throat pressure of ejector (a) and ejector (B) vs. time.

**Figure 7.** The flow state of the water vapor in the ejector.

From **Table 3**, it can be seen that the whole distillation water device runs stably under ejector A, and the water output per unit of electricity is more than 4.7 kg, the energy efficiency of which can be calculated by the following equation:

$$
\varphi = \frac{Q}{P} \tag{1}
$$

**4.2. Experimental results and discussion of capillary**

**Compressor type Effluent** 

**(kg)**

1 TH31 9.8 2 4.90 2 PG108X1 4.8 0.98 4.90 3 KH145 5.2 1.1 4.73

capillary tubes, as shown in **Figure 8**.

**Table 3.** Quantity of distilled water produced.

of the distilled water under No. 1 and No. 2.

**Sizes (inner diameter × length, unit mm)**

**Sizes (inner diameter × length, unit mm)**

**Number of capillaries**

**Experiment number**

**Number of capillaries**

A set of experimental equipment was designed to study the problem of capillary matching for a heat pump distiller. The main equipment include compressor (Panasonic centrifugal compressor, 220 V, 50 Hz, 1700 w), swap body (diameter 15 mm and height 27 cm), frozen water tank (length 30 cm, width 30 cm, and height 40 cm), ejector (inlet diameter 6.5 cm, nozzle diameter 1.2 mm, and speed of evacuation 15 L/s), valve (DC2 4 V), and five different types of

**Energy consumption** 

**(kWhr)**

The simulation test of these five capillary tubes found that the capillary tubes No. 1 and No. 2 were most suitable for this system, where No. 2 was slightly worse than No. 1, and the other three kinds of capillaries were not suitable for the system. And then we are just going to think about the simulation results for the No. 1 and No. 2. **Table 4** shows the voltage, current, and temperature of capillary tube No. 1 and No. 2. **Table 5** shows the electric energy per hour of the system under the capillary No. 1 and No. 2. **Table 6** shows the yield and energy efficiency

> **Electricity (A)**

220 2.8 616 220 2.8 616

220 2.8 616 220 2.8 616

**Table 4.** The voltage, current, and temperature distribution of the compressor for two most suitable capillaries.

**Compressor average power (W)**

**Compressor power (W)**

**System power (W)** **Compressor average power (W)**

**Unit energy consumption** 

89

Distilled Water Production by Vacuum Heat Pump http://dx.doi.org/10.5772/intechopen.76839

**(kg/(kWhr))**

**Consumption of electricity per hour (degree)**

**Voltage (V)**

1 1.7 × 1700 220 2.7 594 608.7

2 1.7 × 1500 220 2.8 616 616

1 1.7 × 1700 608.7 716.7 0.7167 2 1.7 × 1500 616 724 0.724

**Table 5.** Electric energy consumption per hour for two most suitable capillaries.

where Q is the heat produced by distilled water (kJ) and P is the power consumed (kJ). Therefore, the energy efficiency of this device is *<sup>ϕ</sup>* <sup>=</sup> \_\_\_\_\_\_\_\_ 4.7 <sup>×</sup> <sup>2400</sup> <sup>3600</sup> <sup>=</sup> 3.13

**Figure 8.** Five different types of the capillary.


**Table 3.** Quantity of distilled water produced.

From **Table 3**, it can be seen that the whole distillation water device runs stably under ejector A, and the water output per unit of electricity is more than 4.7 kg, the energy efficiency of

*Q*

<sup>3600</sup> <sup>=</sup> 3.13

where Q is the heat produced by distilled water (kJ) and P is the power consumed (kJ).

*<sup>P</sup>* (1)

which can be calculated by the following equation:

**Figure 7.** The flow state of the water vapor in the ejector.

**Figure 6.** Throat pressure of ejector (a) and ejector (B) vs. time.

88 Desalination and Water Treatment

*ϕ* = \_\_

**Figure 8.** Five different types of the capillary.

Therefore, the energy efficiency of this device is *<sup>ϕ</sup>* <sup>=</sup> \_\_\_\_\_\_\_\_ 4.7 <sup>×</sup> <sup>2400</sup>

#### **4.2. Experimental results and discussion of capillary**

A set of experimental equipment was designed to study the problem of capillary matching for a heat pump distiller. The main equipment include compressor (Panasonic centrifugal compressor, 220 V, 50 Hz, 1700 w), swap body (diameter 15 mm and height 27 cm), frozen water tank (length 30 cm, width 30 cm, and height 40 cm), ejector (inlet diameter 6.5 cm, nozzle diameter 1.2 mm, and speed of evacuation 15 L/s), valve (DC2 4 V), and five different types of capillary tubes, as shown in **Figure 8**.

The simulation test of these five capillary tubes found that the capillary tubes No. 1 and No. 2 were most suitable for this system, where No. 2 was slightly worse than No. 1, and the other three kinds of capillaries were not suitable for the system. And then we are just going to think about the simulation results for the No. 1 and No. 2. **Table 4** shows the voltage, current, and temperature of capillary tube No. 1 and No. 2. **Table 5** shows the electric energy per hour of the system under the capillary No. 1 and No. 2. **Table 6** shows the yield and energy efficiency of the distilled water under No. 1 and No. 2.


**Table 4.** The voltage, current, and temperature distribution of the compressor for two most suitable capillaries.


**Table 5.** Electric energy consumption per hour for two most suitable capillaries.


**Author details**

\*, Cai Ling1

People's Republic of China

10.1016/j.desal.2015.05.021

DOI: 10.1016/j.desal.2015.05.023

10.1016/j.apenergy.2015.07.016

DOI: 10.1016/j.desal.2015.08.016

rser.2015.03.065

rser.2015.06.004

, Li Tianyin1

\*Address all correspondence to: lbtjcu@tjcu.edu.cn

Sciences and Technology (NUST), Islamabad, Pakistan

and Sajid Muhammad2

Distilled Water Production by Vacuum Heat Pump http://dx.doi.org/10.5772/intechopen.76839 91

1 Tianjin Key Lab of Refrigeration Technology, Tianjin University of Commerce, Tianjin,

2 School of Mechanical and Manufacturing Engineering (SMME), National University of

[1] Academy, Chinese. "Strategic Research on Sustainable Development of Water Resource

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[3] Hegazy A, Hegazy M, Engeda A. A novel desalination system for utilizing waste heat contained in cooling salt water of a steam plant condenser. Desalination. 2015;**371**:58-66.

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[8] Reif JH, Alhalabi W. Solar-thermal powered desalination: Its significant challenges and potential. Renewable and Sustainable Energy Reviews. 2015;**48**:152-165. DOI: 10.1016/j.

[9] Sahoo U, Kumar R, Pant PC, Chaudhury R. Scope and sustainability of hybrid solar–biomass power plant with cooling, desalination in polygeneration process in India. Renewable and Sustainable Energy Reviews. 2015;**51**:304-316. DOI: 10.1016/j.

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Liu Bin1

**References**

**Table 6.** Production and energy efficiency of distilled water of two most suitable capillaries.

Heat pump water distiller is a device that uses electric energy to produce distilled water, and in this article the energy efficiency is defined as the ratio of water production to electricity consumption. And the higher the energy efficiency is, the more distilled water is produced per kWh, and the more energy-efficient the system. The energy consumed by the system is compressor, pump, fan, and circuit board. As the power of the fan is negligible, the total power is combined with the power of the compressor and the pump. Energy efficiency is the key factor to consider the performance of the system. The purpose of energy-saving optimization is to improve the energy efficiency of the system under the condition of ensuring stable operation. Considering the selection of capillary tubes, in terms of energy consumption or energy efficiency, capillary tube No. 1 is superior to capillary tube No. 2. It is the most suitable system for smooth operation and energy saving.
