Introduction to the difference between the hottest

Introduction to the difference between direct heating heat pump and circulating heat pump

direct heating mode:

a simple understanding is that after the cold water from the outside enters the heat pump unit, it comes out with 60 ℃ hot water, and there is no small water tank inside the equipment. Since there is no circulating water pump between the insulation water tank and the equipment, the start and stop of the equipment are completely controlled by the high and low water level controller of the water tank

the advantages of direct heating are reflected in the following aspects:

no circulating water pump is required, reducing energy consumption and failure probability

after starting up, you can get a continuous stream of hot water at about 60 ℃, without waiting. The water replenishment speed is faster than the circulating type. When the customer Jinan testing machine factory employees use a large amount of table tennis, the safety factor is higher

without any auxiliary heating equipment, the outlet water temperature can reach 65 ℃

the internal condensation system of the equipment operates under the pressure of 20 kg, which reduces the high pressure of the system and makes the compressor operate under light load. Jinan experimental machine factory is a unit specializing in the production of experimental machines to extend the service life of the compressor

direct heating equipment is to make up hot water directly to the hot water tank. Even if the peak maximum water consumption is encountered, the customer's water temperature will not be affected. The volume of insulated water tank is reduced by 30%. Due to the direct hot water supply, even if the user uses up all the water in the insulation water tank, the water temperature in the water tank is maintained at 60 ℃. Module 2: carbon fiber and its composite material design, process, equipment, testing, so it can be used 100%. Due to the cold water replenishment for circulating heating, when a large amount of water is used, the temperature of the water tank decreases significantly, and the temperature of the water tank has been lower than 40 ℃. In order to ensure user requirements, the solution is often to increase the volume of the water tank

direct heating heat pump hot water unit, low-temperature tap water directly absorbs the heat of high-temperature refrigerant, so that the refrigerant is fully cooled, the high-pressure pressure pressure of the system is reduced, and the compressor consumes less electric energy to overcome the system pressure, so as to prolong the service life of the compressor, and the unit has high operation efficiency.

there are two kinds of circulating heating methods:

First: fill the insulation water tank with cold water, The water in the water tank is pumped into the heat pump host through the circulating water pump for heating. Generally speaking, each cycle can raise the temperature of water by about 10 ℃. For example, if we want to heat the water with the temperature of 20 ℃ to 60 ℃, we need the hot water pump to circulate for about 5 times. Moreover, when the temperature of the water tank reaches more than 40 ℃, due to the reduction of the temperature difference, the heat transfer efficiency per unit time will be reduced at the same time, and the later heating efficiency will be greatly reduced from the control system software to the WindowsXP operating system platform

the second kind: a small heat preservation water tank and a large water tank are installed in the heat pump unit. The heat pump unit fills the small water tank with water first, heats the water in the small water tank to 55 ℃, and then transfers the hot water to the large water tank through the circulating water pump. First, the small water tank increases the cost and failure probability of the equipment; On the other hand, increasing the circulating water pump also increases the cost and failure probability of the equipment

in the past research on the circulating heat pump, it was found that most of the time, the water temperature in the water tank was maintained at 50 ℃. When the cold water was added into the water tank, the temperature of the water tank decreased by about 5 ℃. At this time, the temperature sensor of the heat pump drives the heat pump and circulating water pump to start. When the temperature reaches 55 ℃, the equipment stops running. In this way, the number of starts and stops of the equipment every day is maintained at a fairly high frequency. As we all know, the instantaneous current of the compressor is large. Similarly, the high-frequency start and stop of the compressor means that the service life is reduced and the energy consumption is greatly increased

the circulating heating system directly supplies cold water to the hot water tank, which leads to the unstable temperature of the tank, and customers often complain

circulating heat pump hot water unit, when the high-temperature hot water in the water tank absorbs the heat of the refrigerant, the refrigerant is not fully cooled, and the system is in a high-pressure state for a long time. The compressor consumes more electric energy to overcome the system pressure, so that the service life of the compressor is short:

a. Reduce heat absorption through fan speed reduction

ｂ。 Reduce the system pressure through the pressure reducing device

ｃ。 Reduce the refrigerant to reduce the system pressure, and the unit operation efficiency is low