How Does the Swimming Pool Heat Pump Work to Maintain Constant Temperature?

The comfort of swimmers depends largely on the pool water temperature and the parameters of the pool hall air. Air humidity is closely related to people's comfort. Low relative humidity, dry air and low water vapor partial pressure in the air will accelerate the evaporation of moisture on the surface of the wet skin just out of the water, taking away the latent heat of evaporation from the human body, which can easily make people feel cold. At the same time, the heat loss of the indoor swimming pool water is mainly caused by evaporation on the surface of the water body. More water evaporates, the indoor air moisture content increases, and the ventilation required to eliminate the indoor residual moisture increases, which correspondingly increases the load of winter heating and sending fresh air into the room.

If the relative humidity is too high, the indoor air moisture content is too high, which will increase the air dew point and cause condensation on the inner surface of the enclosure structure. Heat loss will also cause serious erosion of the decoration and the uncomfortable feeling of stuffiness for swimmers. At this time, a Swimming Pool Heat Pump is needed.

The international swimming pool design standard stipulates that the water temperature is 26~28℃, the air temperature in the pool hall is 1~2℃ higher than the pool water temperature, the relative humidity is generally 50~70%, but not more than 75%, and the wind speed is controlled at about 0.2m/s.

In short, the working principle of the swimming pool heat pump is to recycle the evaporation heat loss on the surface of the pool water and transfer it into the pool water and air to make up for the heat loss of the pool water and air, while realizing the air conditioning and dehumidification function, and adding a part of the fresh air to the room to ensure the indoor air quality and no condensation. Its working procedure can be roughly divided into two steps:

In the first step, the indoor hot and humid air first passes through the heat exchanger to exchange heat with the outdoor fresh air and becomes warm and humid air. Then the warm and humid air flows through the evaporator, the temperature drops, and the water vapor condenses into cold water droplets and separates from the air, making the air dry and realizing the air dehumidification function; at the same time, the heat energy (latent heat and sensible heat) released during air cooling, water vapor condensation and cooling is absorbed by the refrigerant.

In the second step, the heat energy absorbed by the refrigerant is first (latent heat) heated by the heat exchanger to heat the pool water, realizing the pool water heating function: the waste heat (sensible heat) is passed through the air condenser to heat the cooled indoor air, realizing the air insulation function.

When the heat energy recovered by the Swimming Pool Heat Pump in winter is not enough to meet the requirements, the auxiliary air heater supplements the heat energy required for indoor hot air. The heat pump only needs to provide its own operating power, that is, it can continuously circulate according to the above working procedures, and realize the three functions of pool water heating, air conditioning, and dehumidification with lower energy consumption.

The heat loss of the constant temperature swimming pool mainly includes the following aspects: the pool water loses heat continuously due to evaporation of the water surface, conduction on the water surface, and conduction on the bottom and wall of the pool. More than 90% of the energy loss in the swimming pool is caused by evaporation. Because people swim in the swimming pool, they will lose part of the pool water, which must be replenished continuously, and the replenished water needs to be heated, which requires some heat to be replenished; in addition, the equipment and pipelines of the entire swimming pool are also constantly dissipating heat to the surrounding environment.

All the above-mentioned heat losses need to be continuously replenished by the Swimming Pool Heat Pump and other auxiliary heating equipment to maintain a certain temperature of the pool water. These heat losses plus the heat load of the swimming pool shower can be called regular heat load.

There is also a requirement to replace all the constant temperature pool water at one time. In order to meet the requirements of cleaning and disinfection, it is required to drain all the pool water and re-input warm water within a certain period of time. If the replenished water is cold water (water temperature is 5-15℃), then the heat required to heat the entire pool water is a one-time impact load.