Matching Design Case of Fan Coil Unit in Mechanical Workshop: 10 Elements.

1, Overview of the Project

2, The design ideas

3, Design Basis

4, Calculation parameters

5, Calculation of cooling and heating load

6, Analysis of Operating Expenses

7, System Principle

8, Environmental protection and energy saving

9, Safe and reliable

10, Cold operation

I, Overview of the Project

Name: Casting Machine Processing-China Zhongda Casting

Project Address: Hebei, China
Total construction area: 12,000m2

Room type: steel structure workshop
Heating area: 12,000m2

Wall: color steel composite board
Refrigeration area: 12000 m2.

Heat source equipment: water source heat pump unit

Terminal equipment: general open fan coil unit.

Demand for energy: cooling in summer and heating in winter.

2, The design ideas
The foundry group mainly provides precision machines and parts processing and casting for various countries, so the workshop has high requirements for the ambient temperature, and the parts processing equipment-CNC machine tools have strict requirements for the ambient temperature, and the temperature is too high to operate normally. In addition, it is necessary to save the operating cost.

According to the adjustment of the national energy policy and the requirements for environmental protection, the use of clean, energy-saving, and efficient new energy will be the main policy of the country for a long time to come. In order to meet the special requirements of workshop temperature and respond to the call of national policy, the engineer comprehensively considered that the water source heat pump was selected as the main engine, and the end equipment was matched with the general fan coil, which not only met the special temperature requirements of machining precision machine tools but also saved the cost for production enterprises.

In this scheme, electricity is used as a clean energy source for refrigeration and heating. By consuming a small amount of electric energy, low-grade heat energy in the atmosphere can be converted into high-grade heat energy, and water source heat pump units can be used to produce cold water and hot water for building refrigeration and heating.

The utilization of this new energy can completely replace municipal central heating, coal-fired, fuel-fired, gas-fired, electric heating, and other forms of heating, and it can also be cooled in summer, which greatly reduces the investment, and is not affected by the ambient temperature and does not need auxiliary electric heating. The system has the advantages of strong stability, high reliability, good heating effect, environmental protection, and no pollution, and does not need special management. Under the normal working conditions of the terminal pipe network and heat sink, the indoor temperature reaches or exceeds the standard specified in the Measures for Heat Supply in Hebei Province.

3, Design Basis

According to the meteorological data of Hebei Province;  

Technical Code for Design, Installation, and Engineering Acceptance of Heat Pump Heating System (GB/T 8713-2002);

Code for Acceptance of Construction Quality of Building Water Supply and Drainage and Heating Engineering (GB50242-2002);

Design and Installation of Water Source Heat Pump Heating and Hot Water System GB/T 15513-1995;

Code for Design of Building Water Supply and Drainage (GB/T 50015-2003);

Drawing Standard for Water Supply and Drainage (GB/T 50019-2003);

Design Manual of Heating, Ventilation, and Air Conditioning
This design is to adjust and control the temperature, humidity, cleanliness, and air velocity in the space after calculation according to the local climate, environment, and buildings, so as to create a safe, environmentally friendly, comfortable, and energy-saving harmonious environment for users.

4, Calculation parameters
Table 1 Calculation parameters of the outdoor design in summer in Hebei

Table 1 Calculation parameters of the outdoor design in winter in Hebei

Table 2 Calculation parameters of indoor design in winter

5, Calculation of cooling and heating load

According to the design manual of heating, ventilation, and air conditioning, the cooling and heating heat loads are composed of the basic cooling/heat consumption of the outer envelope and the inner envelope and its additional cooling/heat consumption and cold air infiltration cooling/heat consumption. According to the outdoor temperature parameters of Hebei, the design unit cooling load index is 110W/㎡ , and the unit heating load index is 100W/㎡.

Determination of cooling load;
            Q1=12000×110×=1320kw
Combined with the characteristics of buildings and climatic conditions, the rated cooling capacity of the water source heat pump with refrigeration configuration should be ≥ 1,320kW to meet the use requirements.

Determination of heat load;
            Q2=12000×100=1200kw
Combined with the characteristics of buildings and climatic conditions, the rated heat of the water source heat pump for heating configuration should be ≥1200kw to meet the use requirements.

6, Analysis of Operating Expenses
Forecast the heating energy consumption and calculate the total power consumption. According to the daily heating operation of 8 hours, the heating season of 120 days, the electricity price of 0.8 yuan/kWh is equivalent to the operating cost per square meter (the whole heating season), and the indoor temperature reaches 20℃ 2℃. The following predicted energy consumption does not include the operating energy consumption of the system circulating water pump.

7, System Principle

The heat pump absorbs a large amount of heat energy from circulating water with little electric energy, and it is compressed by a compressor to become high-temperature heat energy, which transfers the water to heat the water. The hot water is used for heating through a fan coil and can provide cooling in summer.

8, Environmental protection and energy saving
The heating power is the heat energy of circulating water, which only needs to consume a little electricity when absorbing the heat energy of circulating water, and the thermal efficiency is as high as 520%-780%. Compared with traditional energy sources, it not only has high thermal efficiency but also avoids the pollutant emission caused by the use of chemical energy, thus achieving the dual effects of energy-saving and environmental protection. The space fan coil unit is used for refrigeration and heating, and the overall operation and automatic temperature adjustment make the operation more stable and energy-saving.

9, Safe and reliable
By adopting the physical working method, no toxic gas will be produced in the whole heating process, and in this process, no leakage accident will occur due to the separation of water and electricity.

10, Cold operation
Not affected by the environment, available all year round. Whether it is rainy or cold in winter, the intelligent control of the heat pump unit can save manpower investment and ensure all-weather synthesis of high-temperature heat sources.