Engineering overview
- Project Name: Residential Building of Nursing Home
- Project address: Hebei Province
- Total construction area: 15000 ㎡.
- House type: residential building
- Heating use area: 11,500㎡
- wall body: 37 CM external wall with thermal insulation Refrigeration Area: 11,500㎡
- Heat source equipment: ultra-low temperature air source heat pump
- Indoor system equipment: horizontal concealed fan coil unit’s
- Functional requirements: cooling in summer and heating in winter
Design ideas
The nursing home is divided into six districts: self-care district, non-self-care district, apartment district, internal restaurant, external restaurant and hospital. The buildings in each district are scattered. In addition, each district has different requirements for central air-conditioning system and needs to operate independently. According to the adjustment of national energy policy and the requirements for environmental protection, the use of clean, energy-saving and efficient new energy is the main policy of the country for a long time in the future. Therefore, engineers independently match the air-conditioning system scheme for each district, and satisfy each district the heat source requirements.
In this scheme, electric power is used as the clean energy source for cooling and heating. By consuming a small amount of electric energy, the low-grade heat energy in the atmosphere is converted to high-grade heat energy, and the ultra-low temperature air source heat pump unit is used to prepare cold water and hot water for cooling and heating of buildings. The utilization of this new energy can completely replace the municipal central heating and any heating methods such as coal, fuel, gas and electric heating, and can also refrigerate in summer, which greatly reduces the investment, and can still run normally and efficiently in the ultra-low temperature environment of -25℃ without auxiliary electric heating. The system has strong stability, high reliability, good heating effect, environmental protection and no pollution, and no special person is needed to manage it. Under the normal working condition of fan coil unit (cooling device), the indoor temperature reaches or exceeds the standard specified in Hebei Province’s Measures for Heating.
Calculation parameters
Form 1 Calculation parameters of outdoor design in summer in Hebei Province
| Seasonal parameters | Average minimum temperature | maximum temperature | Relative humidity% | Outdoor average wind speed (m/s) | Atmospheric pressure KPa |
| summer | 27 | 34 | 55 | 1.5 | 102 |
Form 1 Calculation parameters of outdoor design in winter in Hebei Province
| Seasonal parameters | Average minimum temperature | Extremely cold minimum temperature | Relative humidity% | Outdoor average wind speed (m/s) | Atmospheric pressure KPa |
| winter | -7 | -15 | 55 | 1.5 | 102 |
Heat load calculation of heating
According to the Design Manual of Heating, Ventilation and Air Conditioning, the cooling and heating heat load consists 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 in Hebei, the unit cooling load index is 120W/㎡, and the unit heat load index is 80W/㎡.
Considering the usage habit of summer refrigeration in this project, the comprehensive utilization rate is 70%, which can reduce the investment cost. Each room can independently control the temperature according to the usage condition, which makes the use more flexible, the operating cost is independently calculated, and the operating cost can be saved greatly.
Determination of cooling load
Q1=11500×120×70%=966kw
According to the characteristics of buildings and climatic conditions, the rated refrigerating capacity of ultra-low temperature air source heat pump should be ≥966kw to meet the use requirements.
Determination of heating load
Q2=11500×80=920kw
According to the characteristics of buildings and climatic conditions, the output heat of ultra-low temperature air source heat pump with average minimum temperature of -7℃ should be ≥920kw to meet the use requirements.
System Principle
Air Source Heat pump absorbs a large amount of low-temperature heat energy in the air through very little electric energy, which is compressed by the compressor and changed into high-temperature heat energy, and the water is transferred to heat the water. The hot water is used for heating through the fan coil, and can provide summer refrigeration.
Environmental protection and energy saving
The power of heating is free air heat energy, which only needs to consume a little power when absorbing air heat energy, and the thermal efficiency is as high as 270%-430%. 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 conservation and environmental protection. Indoor rooms are cooled and heated by fan coil units, which operate independently and automatically adjust the temperature, making the operation more stable and energy-saving.
Safe and reliable
By adopting physical working method, no toxic gas will be produced during the whole heating process, and no leakage accident will occur during the separation of water and electricity.
low temperature operation
Not affected by the environment, it can be used all the year round. Whether in rainy days or cold winter, the intelligent control of heat pump unit can save manpower investment and ensure all-weather synthesis of high-temperature heat source.
