Economic analysis of split water source heat pump unit

Economic analysis summary of split water source heat pump unit By introducing the split water source heat pump air conditioning unit, and comparing it with other central air conditioning systems in terms of project cost and operation energy consumption, which air conditioning mode should be selected to save energy in air conditioning engineering design Split water source heat pump Energy saving and environmental protection engineering cost

The economic analysis of the wall split – water source heat pump unit summaryabstract: through introduction of the wall split water source heat pump unit and the comparison of the analysis of the cost of the project, energy consumption, Which air conditioner we can find more energy saving when air conditioner project designing.keyword: wall split water source heat pump / energy saving and environmental protection / cost of the project / operating energy consumption introduction: central air conditioning system is widely used for air conditioning in modern buildings, Air conditioning energy consumption accounts for more than 60% of the whole building energy consumption. With the continuous increase of modern buildings in urban construction, the proportion of air conditioning energy consumption in urban energy consumption is also increasing. Air conditioning power consumption has become a large power consumer in China. Due to the characteristics of centralized use time and large seasonal load, air conditioning aggravates the contradiction between peak and valley power, which degrades the load characteristics of power system and reduces the load rate of power grid, resulting in a waste of resources of power facilities. According to the current power consumption situation, only by improving the energy efficiency ratio of central air conditioning and reducing system energy consumption can we improve the domestic power load characteristics, reduce the proportion of peak power load, and achieve the purpose of energy conservation and safe power consumption.

Split water source heat pump unit is a new environmental protection air conditioner with high energy efficiency ratio, which can be widely used in office buildings, hotels, hotels, apartment buildings, karaoke rooms and other home and commercial places. Introduction to split water source heat pump unit: split water source heat pump unit is a new type of air conditioner between air-cooled split air conditioner and water-cooled integral air conditioner. It uses refrigerant as refrigeration medium and water as cold (heat) source. Its cold (heat) source can be cooling tower cooling water (boiler hot water), surface water and even geothermal (soil heat). The water temperature of this continuous circulation system generally needs to be maintained between 15 ~ 35 ℃. When the circulating water temperature is lower than 15 ℃, it can be heated with the help of heating device. When the circulating water temperature is higher than 35 ℃, it can be cooled by cooling tower to maintain normal operation. Indoor air supply can be either side outlet air supply or air duct system. Cold and hot air are sent to indoor rooms through independent air duct system, and the return air can return to the unit through the gap under the door, auxiliary rooms and walkways; It can also be returned to the unit by the return air duct.

The split water source heat pump unit has the following characteristics: 1 High energy efficiency ratio, water is used as heat dissipation and cooling medium, so the unit has high energy efficiency, energy saving and high efficiency, and saves operation cost. 2、 The project has the advantages of short investment cycle, flexible investment and low cost. It can be invested by stages according to the needs of users, and the initial investment cost is low. The water pipe does not need thermal insulation to reduce the investment cost. At the same time, it can completely solve the dripping problem of the traditional central air conditioning refrigeration water pipe system. 3、 The unit is small, easy to install and flexible. The split water source heat pump unit is divided into internal unit and external unit. The internal unit structure is similar to the concealed direct cooling fan coil unit; The main structure of the external unit includes refrigeration and heating components such as compressor, condenser and four-way raft. It is called “external unit”. In fact, it is generally installed indoors. Separate the compressor, condenser, etc. from the air supply coil, on the one hand, reduce the size of the unit, so that the height of the inner unit is less than 250mm and the height of the outer unit is less than 500mm, which is convenient for hidden installation, saves space and improves the flexibility of installation; It can be installed in full cooperation with the decoration design according to the decoration needs. On the other hand, it reduces the indoor noise. The external unit can be installed in the corridor, toilet, kitchen ceiling, balcony and other positions to avoid the impact of noise on the indoor; Following the economic analysis of split water source heat pump unit, a simple comparison is made on the initial investment, long-term operation cost, energy saving, applicability and other performance of several main large-scale central air conditioning forms.

I Comparison of initial investment cost: the central air conditioning configuration scheme includes the following types: (a) water-cooled central air conditioning unit (b) air-cooled central air conditioning unit (c) split water source heat pump air conditioning unit II Analysis of operation energy consumption and long-term operation cost the huge energy consumption of large central air conditioning has always been a difficult problem for manufacturers and users. The energy consumption of cold and heat sources is the vast majority of the energy consumption of the central air conditioning system. The large centralized cold and heat source central air conditioning can only rely on the reasonable allocation of units to meet the energy-saving needs under different service load conditions. When the service load of the air conditioning fluctuates widely or does not meet the design estimation conditions, the energy-saving effect is poor.

If large air-cooled and water-cooled central air conditioning units do not adopt other energy-saving means, the electricity charge for long-term operation under full load is very high and the energy waste is very large. Comparison of energy consumption estimation for full load operation of each air conditioning system name of the system project name water cooled central air conditioning unit air cooled central air conditioning unit split water source heat pump air conditioning unit project cost (yuan / kW) 1450 ~ 1500 1800 ~ 2000 1500 ~ 1600 energy consumption ratio (kW / kW) 4.1 ~ 4.6 2 2.6 ~ 3.2 3.2 ~ 4.0 refrigeration energy consumption (kW / RT) 0.85 ~ 0.75 1.35 ~ 1.1.1 ~ 0.88 cooling water tower energy consumption (kW / RT) 0.05/0.05 cooling water pump energy consumption (kW / RT) 0.1 / / chilled water pump energy consumption (kW / RT) 0.1 0.1/indoor end energy consumption (kW / RT) 0.15 0.15 0.1 total energy consumption (kW / RT) 1.25 ~ 1.15 1.6 ~ 1.35 1.25 ~ 1.03 basic electricity price (yuan / kWh) 0.8 0.8 0.8 annual energy consumption (10000 yuan) 24.9 ~ 22.9 31.9 ~ 26.9 24.9 ~ 20.5 note: 1) annual energy consumption is calculated according to 2000 square meters of air conditioning area, taking 150W / m2, 8 hours per day; According to the actual project operation records, the energy consumption of split water source heat pump is only 7 / 10 times that of water cooling and cold water, 6 / 10 times that of air cooling heat pump, and 3 / 10 times that of electric heating during heating. 2) the initial investment is the project cost, including equipment cost and project installation cost. The main equipment includes air conditioning host, terminal equipment, cooling water tower, cooling water pump Chilled water pump, etc; The project installation includes the installation cost of cooling water, chilled water transmission pipeline, equipment, relevant accessories, construction labor cost, etc. 3) For ease of comparison, the above data are the power consumption under the maximum service load, and the energy-saving capacity of split water source heat pump air conditioning under insufficient load is not considered. 4) Pipe loss and empty consumption are not considered for large central air conditioning units.

In actual use, due to the energy loss of long-distance cooling water pipeline transmission, and the excess power of the main engine caused by load change in use, the pipe loss and empty consumption can generally account for more than 15% of the full load. III Compared with other forms of central air conditioning, split water source heat pump unit has more operation flexibility:

• 1) The operation mode is flexible, which can realize the simultaneous cooling and heating of units in different spaces in the transition season, so as to save energy consumption in the transition season;
• 2) The split water source heat pump unit disperses the cold and heat sources of the air conditioner to each room, so that the total operating power of the air conditioner is completely matched with the actual cooling load, so as to avoid the widespread empty consumption waste of large centralized cold and heat source central air conditioner. The cooling water transmission pipeline does not need thermal insulation, which not only reduces the initial investment, but also eliminates the “pipe loss” in the process of chilled water transmission and reduces energy waste. (according to the experiment of Shenzhen Academy of Building Sciences, the cooling capacity loss per kilometer during chilled water transportation is about 10%)
• 3) Compared with air-cooled unit, split water source heat pump unit adopts water cooling mode to improve unit energy efficiency ratio and reduce actual operation energy consumption; 4) It is convenient to combine with ground temperature, cold storage and other energy-saving means to further reduce energy consumption and reduce operation cost;
• 5) Intelligent remote control is available. The charging is convenient, which is convenient for household independent control and separate charging, and there is no need to install expensive heat meter;
• 6) Each air conditioning unit is independent, and the normal operation of other units will not be affected during maintenance or overhaul;
• 7) The equipment can be purchased by stages, and only the cooling water system can be installed in advance. The air conditioning unit can be purchased and installed in the later stage according to the needs, so as to reduce the pressure of one-time investment;
• 8) The cooling water system is simple and reliable, and the technical requirements for maintenance and management are low.

It only needs ordinary technicians to carry out maintenance, so as to reduce personnel management and maintenance costs; After comparing the initial investment and long-term operation cost of the main central air-conditioning systems, we can draw the following conclusions:

• 1) the initial investment of split water source heat pump air-conditioning is slightly higher than that of water-cooled central air-conditioning units (an increase of about 3% ~ 6%) and lower than that of air-cooled central air-conditioning;
• 2) However, compared with the centralized central air conditioning unit, split water source heat pump air conditioning saves about 10 ~ 30% energy. If considering the air consumption and pipe loss saved under the condition of under load operation and the energy consumption saved in the transition season, the effect of saving long-term operation cost is more significant.
• 3) The efficiency improvement of split water source heat pump air conditioning unit leads to a slight increase in cost. However, from the energy-saving effect brought by the improvement of energy efficiency ratio, the benefits of power saving will exceed the cost added value, reduce the power demand and save power resources.

The gains outweigh the losses, and the advantages outweigh the disadvantages. Pan Yaping (1968 ~), male, postgraduate, engaged in central air conditioning market research and promotion, Liang Jiemin (1974 ~), male, University, Vice Minister of engineering technology, contact address: Zhigao air conditioning commercial engineering technology department, Nanhai District, Foshan City, Guangdong Province, zip code: 528244 Tel: (0757) 85623712e-mail: [email protected] References: [1] Zhao Yirong et al Air conditioning China Construction Industry Press [2] design standard for energy efficiency of civil buildings (heating residential buildings) JGJ26-95.1995