1.Research and Development Background

The environmental characteristics inside underground building caverns are low temperature and high humidity. Due to the large enthalpy difference between the air inside and outside the caverns in summer, ordinary dehumidifiers do not have sufficient cooling capacity to control the dew point temperature of fresh air low enough, making it difficult to ensure that fresh air does not condense after entering the underground building caverns, which brings many problems to the design and operation of ventilation and dehumidification systems; Simultaneously, discharging the processed indoor air directly to the outside can also result in significant energy waste; In addition, the inconvenience in space required for cooling towers or outdoor units involved in underground air conditioning projects, as well as the significant energy loss caused by long-distance pipeline transportation, etc; Based on this, our company has developed and designed a specialized dehumidifier air conditioner for underground engineering. This model adopts dual cold source evaporative heat pump temperature control and dehumidification technology, recovers exhaust heat, integrates cooling, heating, temperature control and dehumidification functions, and meets customer needs in multiple aspects; In addition, the model adopts an integrated frame structure in terms of structure, which avoids energy loss caused by long-distance pipeline transportation and inconvenience in external space, and greatly improves energy efficiency. It can effectively solve the external connection and energy consumption problems of underground commercial street projects and other underground projects.

2.Product working principle and energy-saving principle

The dual cooling high-efficiency heat pump type underground engineering dedicated dehumidification air conditioning unit integrates refrigeration, heating, and temperature control dehumidification without blind spots, including refrigerant circulation system, refrigerant circulation system, and heat and moisture exchanger; By sequentially connecting various components of the refrigerant circulation system, multiple functions such as refrigeration, dehumidification, and heating can be achieved. By sequentially connecting various components of the refrigerant circulation system, the function of temperature regulation without blind spots can be realized. In summer, the unit adopts a heat and moisture exchanger to evaporate through direct contact between air and water, greatly improving the condensation effect. With only partial exhaust, underground engineering can operate without outdoor units. In order to meet the requirements of energy conservation and environmental protection, heat pump technology is used in winter to recover the energy of exhaust air, while passing the indoor exhaust air through an evaporator to ensure that it remains at the ambient temperature-10Efficient and stable operation below ℃.

The biggest difference between the split unit of the dual cooling high-efficiency heat pump dehumidification air conditioner and other air conditioners and dehumidifiers is that this unit has air cooling+Water evaporation cold condenser - heat pump refrigeration system; Summer air conditioning dehumidification can eliminate waste heat and humidity in the project, ensuring that the temperature and humidity inside the project meet the requirements for use; Heating in winter to meet internal heating requirements.

1Cooling conditions

When the refrigeration compressor is working, low-temperature and low-pressure refrigerant gas is sucked in from the evaporator (indoor heat exchanger), compressed into high-temperature and high-pressure gas by the compressor, and enters the condenser (outdoor heat exchanger) After condensation, it becomes a liquid, releases heat, and enters the evaporator (indoor heat exchanger) after being throttled by the thermal expansion valve Absorb heat, evaporate into gas, and then enter the compressor through the suction pipe to complete a refrigeration cycle.

Indoor return air is mixed with fresh air and flows through the evaporator (indoor heat exchanger) to transfer heat energy to the refrigerant. The air temperature drops below its dew point, forming condensation on the evaporator. The formed moisture flows into the condensate collection tray of the equipment. Low temperature and low humidity air is introduced into the room to eliminate residual heat and humidity.

Part of the indoor return air (exhaust air) is mixed with fresh air and flows through the condenser (outdoor heat exchanger) to remove heat from the refrigeration system and discharge it outdoors.

Due to the use of air cooling+Water evaporation cooling, good condensation effect, reduced condensation pressure, unitCOPImprove.

2Heating conditions

When the refrigeration compressor is working, the four-way reversing valve is energized, and low-temperature and low-pressure refrigerant gas is sucked in from the evaporator (outdoor heat exchanger), compressed into high-temperature and high-pressure gas by the compressor, and enters the condenser (indoor heat exchanger) After condensation, it becomes a liquid, releases heat, and enters the evaporator (outdoor heat exchanger) after being throttled by the thermal expansion valve Absorb heat, evaporate into gas, and then enter the compressor through the suction pipe to complete a refrigeration cycle.

Indoor return air is mixed with fresh air and flows through the condenser (indoor heat exchanger) to obtain heat from the refrigeration system. The air temperature rises, and high-temperature air is sent into the room to increase the indoor temperature.

Part of the indoor exhaust passes through the evaporator (outdoor heat exchanger) to transfer heat to the refrigeration system.

Due to the higher indoor exhaust temperature and evaporation pressure in winter compared to outdoor air, the probability of frost formation is reducedCOPImprove and stabilize heating.

3Principle of Temperature Adjustment for Refrigerant

When the dual cooling high-efficiency heat pump dehumidification air conditioning unit operates in the cooling condition, the four-way valve starts the cooling setting, and the refrigerant circulation system water pump runs: the high-temperature and high-pressure gas discharged by the compressor first passes through the water-cooled condenser to release some heat to the refrigerant for condensation, and then enters the condenser through the four-way reversing valve to release the remaining heat to the outdoor air for condensation. The condensed liquid then enters the refrigeration expansion valve for throttling and pressure reduction, and then enters the evaporator to absorb the energy in the indoor air for evaporation. The evaporated gas is finally sucked in by the compressor and compressed into high-temperature and high-pressure gas, which is discharged again, thus completing the refrigeration cycle of the refrigerant.

4Evaporation principle

The air flow through the condenser consists of return air (exhaust air) and partially supplemented fresh air. In summer, the unit adopts a heat and moisture exchanger to evaporate through direct contact between air and water, forming a layer of condensed water film on the surface of the heat and moisture exchanger. The evaporation of water molecules absorbs the latent heat of vaporization, reducing the air temperature and greatly improving the effectiveness of the air condenser.

Product advantages:

1The dual cooling high-efficiency heat pump type underground engineering dedicated dehumidification air conditioning unit integrates refrigeration, heating, and dehumidification air conditioning. The unit adopts the air-cooled technology developed by our company+Water evaporation cooling heat and moisture exchanger (condenser or evaporator), in summer, directly contacts with the condenser through air and water, achieving a dual cooling method of air cooling and water evaporation, greatly improving the condensing and cooling efficiency of the unit, reducing the compressor shaft power, and saving energy consumption.

2Air cooling+The water evaporation cooling heat and moisture exchanger (condenser or evaporator) is an integral unit that can be installed in the engineering exhaust room near the air conditioning unit. In summer, the exhaust inside the engineering will be used（27By using a condenser at around ℃, the condensing and cooling efficiency of the unit can be improved, the compressor shaft power can be reduced, and energy consumption can be saved. Ventilation inside the project during winter（18By passing through the condenser at around ℃, the heating efficiency of the unit can be improved while preventing the evaporator from freezing, ensuring that the unit can operate normally under low temperature conditions.

3The unit requires less air volume compared to the outdoor unit of air-cooled dehumidifier air conditioning units. By simply passing the air to be removed from the project through pipelines and passing it through a condenser (or evaporator), underground projects can operate without an outdoor unit;

4By passing the exhaust air with lower indoor temperatures in summer or higher temperatures in winter through a heat exchanger, the refrigeration efficiency is improved, and the energy recovery of the exhaust air is achieved, which can reduce operating costs.

5The cooling and dehumidification of the unit in summer and heating and heating in winter ensure the temperature and humidity requirements of the internal environment of underground engineering in different seasons.

6The units can be set up separately according to the division of air conditioning and fire protection zones in underground commercial streets, solving the problems of equipment operation management and energy consumption measurement for tenants in different commercial areas, avoiding the large system operation of traditional air conditioning methods, which are difficult to manage and consume a lot of energy.

7This unit does not require a cooling tower or outdoor unit.

Unit components

1The key components such as compressors and thermal expansion valves are all original imported products with reliable performance;

2The refrigerant used in the refrigeration system of the dehumidifier air conditioner isR22, can also be usedR407c、R410aWaiting for environmentally friendly working fluids;

3The dehumidifier air conditioner adopts Siemens technologySIEMENSPLCS7-200Realize intelligent control of the unit, and can achieve central monitoring according to customer requirements, connected to the building control system（RS485InterfaceModBUSAgreement).

4The dehumidification air conditioning unit adopts modular design, which maximizes the adaptability to customers' flexible and personalized needs, and also meets the standardization of the entire product process;

5The dehumidification air conditioning unit displays multiple parameters, such as temperature and humidity, working status, fault information, etc., and has multiple protection functions;

6The dehumidification air conditioning unit can control and display the working status of auxiliary equipment (such as fans, etc.). We recommend that users directly connect the auxiliary equipment to the unit to ensure the correct start stop sequence between the unit and the auxiliary equipment;

7The dehumidification air conditioning unit adopts steel or aluminum alloy frame and color steel panel;

Convenient access doors and detachable panels provide an open maintenance space for all internal components of the equipment.

8The fan and motor are optimized using professional selection software to obtain the best working point, efficiency, and noise level.

Design selection instructions:

1Structural description:

The dual cooling high-efficiency heat pump type underground engineering dedicated dehumidification air conditioning unit adopts modular design, which can be selected according to the size of the air conditioning area. Divided into several functional sections, suitable for the transportation and installation of conventional doorways in underground engineering and other projects; For projects with special requirements, detailed requirements can be provided when ordering to ensure that the equipment meets the installation needs of users. The unit structure is mainly divided into two parts: air-cooled+Water evaporation cold condenser and main unit+evaporator+New return air mixing+Supply fan. The former part is installed in the exhaust room or adjacent air conditioning room, while the latter part can be integrated and installed in the air conditioning room.

2Function type description:

Underground shopping malls and entertainment centers are generally located in bustling central areas. Due to the lack of suitable installation locations for cooling towers or outdoor air conditioning units, as well as the impact of noise from cooling towers or outdoor air conditioning units on the environment, dual cooling high-efficiency heat pump type underground engineering specific dehumidification air conditioning units can be selected. When underground defense engineering and civil defense engineering have a large exhaust volume, dual cooling high-efficiency heat pump type underground engineering dedicated dehumidification air conditioning units can also be selected.

4Air cooling of dual cooling high-efficiency heat pump type underground engineering dedicated dehumidification air conditioning unit+The room for water evaporation cold condenser needs to be reserved with water pipes, drainage pipes, and exhaust pipes; host+evaporator+New return air mixing+Power supply is required in the fan room.

5To ensure the smooth discharge of condensate water from the unit and prevent water leakage, it is best to use negative pressure in the heat exchanger section.

6The fan of the dual cooling high-efficiency heat pump type underground engineering special dehumidification air conditioning unit is designed according to the conventional requirements of underground engineering, and can also be configured according to the air volume and pressure requirements proposed by the HVAC designer to meet the design requirements.

7When the user's HVAC system requires centralized control, our company can undertake the design, installation, and commissioning of the control system.

Parameters of dual cooling high-efficiency heat pump type underground engineering dedicated dehumidification air conditioning unit:

Performance parameter table of dual cooling high-efficiency heat pump type underground engineering dedicated dehumidification air conditioning unit (integrated unit)ZCK50-

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