A dual-cold source low dew point direct expansion dehumidification unit

Abstract

The utility model relates to the technical field of direct expansion dehumidification air-conditioning units, and specifically discloses a dual-cold-source low-dew-point direct expansion dehumidification unit, including a unit air duct and a condensing heat circulation mechanism, the unit air duct is provided with a surface cooling coil, a "V"-shaped two-stage evaporator is installed at the outlet of the surface cooling coil, a steam heater and a steam humidifier are installed at the outlet of the "V"-shaped two-stage evaporator, and a blower is installed at the rear of the steam humidifier; the condensing heat circulation mechanism includes a three-pipe outdoor unit and a reheating fan, the three-pipe outdoor unit includes a liquid supply pipe, a return air pipe and a hot air bypass pipe, the hot air bypass pipe is connected to the reheating fan, and the reheating fan is installed between the "V"-shaped two-stage evaporator and the steam heater in the unit air duct; the utility model has better environmental adaptability, reliability and convenience; the condensation waste heat of the direct expansion dehumidification system is recycled and utilized for air supply reheating, the heating input is reduced, the structure is simple, and the energy consumption is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of direct expansion dehumidification air conditioning units, in particular to a dual-cold-source low-dew-point direct expansion dehumidification unit. Background Art

[0002] At present, for the purification area with low-temperature air supply, the cooling refrigeration system generally uses ethylene glycol aqueous solution of different concentrations as the coolant. The low temperature and high humidity environment easily causes frost on the surface cooler and affects the normal operation of the refrigeration system. The traditional defrosting methods suitable for refrigeration systems, such as electric heating defrosting, hot water defrosting, and steam defrosting, have the disadvantages of complex defrosting systems, poor environmental adaptability, and high defrosting energy consumption.

[0003] An analysis is conducted on the many defects existing in traditional defrosting methods. For example, when hot water or steam is used for defrosting, the defrosting system is complicated, which is not conducive to construction and maintenance management; the defrosting function cannot be achieved when there is a lack of steam source or hot water; the electric defrosting method has high energy consumption, etc.

[0004] Therefore, it is necessary to design a dual-cold-source low-dew-point direct expansion dehumidification unit to solve the problems of the traditional defrosting system of the refrigeration system being more complicated, having poor environmental adaptability, and having higher defrosting energy consumption. Utility Model Content

[0005] In view of the problems existing in the prior art, the purpose of the utility model is to provide a defrosting method for a dual-cold source low dew point direct expansion dehumidification unit using a dual-channel continuous air supply system and a new alternating defrosting method using condensation heat as the defrosting heat source.

[0006] The technical solution adopted by the utility model to solve the technical problem is: a dual-cold-source low-dew-point direct expansion dehumidification unit, including a unit air duct and a condensing heat circulation mechanism, the unit air duct is provided with a surface cooling coil, a "V"-shaped two-stage evaporator is installed at the outlet of the surface cooling coil, a steam heater and a steam humidifier are installed at the outlet of the "V"-shaped two-stage evaporator, and a blower is installed at the rear of the steam humidifier;

[0007] The condensing heat cycle mechanism includes a three-pipe outdoor unit and a reheat fan. The three-pipe outdoor unit includes a liquid supply pipe, a return air pipe and a hot gas bypass pipe. The hot gas bypass pipe is connected to the reheat fan, and the reheat fan is installed between the "V"-shaped two-stage evaporator and the steam heater in the air duct of the unit.

[0008] Specifically, a fresh air inlet is provided on the outer shell at the front of the air duct of the unit, a primary filter is installed on the inner side of the fresh air inlet, and a surface cooling coil is installed at the outlet of the primary filter.

[0009] Specifically, a return air inlet is also provided on the outer shell of the air duct of the unit, and the return air inlet is located between the surface cooling coil and the "V"-shaped two-stage evaporator.

[0010] Specifically, an air supply port is arranged on the outer shell at the rear of the air duct of the unit, and a medium-efficiency filter is installed on the inner side of the air supply port.

[0011] Specifically, the liquid supply pipeline is connected to two liquid supply branches, and the two liquid supply branches are respectively connected to the two evaporators of the "V"-shaped two-stage evaporator. The outlet pipes of the two evaporators of the "V"-shaped two-stage evaporator are respectively connected to three-way valve one and three-way valve two. Refrigeration expansion valve one and refrigeration expansion valve two are respectively installed on the two liquid supply branches. Refrigeration expansion valve one is connected in parallel with one-way valve one through a pipeline, and refrigeration expansion valve two is connected in parallel with one-way valve two through a pipeline.

[0012] Specifically, the middle part of the hot gas bypass pipeline is respectively connected to the three-way valve 1 and the three-way valve 2 through two hot gas branch pipes, and the three-way valve 1 and the three-way valve 2 are both connected to the return air pipeline.

[0013] Specifically, the outlet pipe of the reheat fan is connected to the liquid supply branch pipe, and a thermal expansion valve is installed on the outlet pipe of the reheat fan.

[0014] The utility model has the following beneficial effects:

[0015] The dual-cold source low dew point direct expansion dehumidification unit designed by the utility model utilizes a dual-channel continuous air supply system defrosting method, with the goal of improving the environmental adaptability, reliability and convenience of the defrosting system; a new alternating defrosting method using condensation heat as the defrosting heat source is adopted, which has the advantages of better environmental adaptability, reliability and convenience compared to traditional defrosting methods.

[0016] The dual-cold-source low-dew-point direct expansion dehumidification unit designed by the utility model recycles the condensation waste heat of the direct expansion dehumidification system to reheat the air supply, thereby reducing the heating input, having a simple structure and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of a mixed air type low-temperature regenerative rotary dehumidification unit.

[0018] In the figure: 1-unit air duct, 1.1-fresh air inlet, 1.2-return air inlet, 1.3-primary filter, 1.4-surface cooling coil, 1.5-"V" type two-stage evaporator, 1.6-steam heater, 1.7-steam humidifier, 1.8-air blower, 1.9-medium efficiency filter, 1.10-air outlet;

[0019] 2- condensing heat circulation mechanism, 2.1- three-pipe outdoor unit, 2.2- liquid supply pipe, 2.3- air return pipe, 2.4- hot gas bypass pipe, 2.5- reheat fan, 2.6- thermal expansion valve, 2.7- refrigeration expansion valve one, 2.8- one-way valve one, 2.9- refrigeration expansion valve two, 2.10- one-way valve two, 2.11- three-way valve one, 2.12- three-way valve two. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely further describe the technical solutions in the embodiments of the utility model. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] Embodiment 1:

[0022] like Figure 1 As shown, a dual-cold-source low-dew-point direct expansion dehumidification unit includes a unit air duct 1 and a condensing heat circulation mechanism 2. The unit air duct 1 is provided with a fresh air inlet 1.1, a return air inlet 1.2, a surface cooling coil 1.4, a "V"-shaped two-stage evaporator 1.5, a steam heater 1.6, a steam humidifier 1.7, a blower 1.8, and an air supply port 1.10. A fresh air inlet 1.1 is provided on the outer shell of the front part of the unit air duct 1, a primary filter 1.3 is installed on the inner side of the fresh air inlet 1.1, and a surface cooling coil 1.4 is installed at the outlet of the primary filter 1.3. A "V"-shaped two-stage evaporator 1.5 is installed at the outlet of the surface cooling coil 1.4, and a return air inlet 1.2 is also provided on the outer shell of the unit air duct 1, and the return air inlet 1.2 is located between the surface cooling coil 1.4 and the "V"-shaped two-stage evaporator 1.5.

[0023] A steam heater 1.6 and a steam humidifier 1.7 are installed at the outlet of the "V" type two-stage evaporator 1.5, and a blower 1.8 is installed at the rear of the steam humidifier 1.7. An air outlet 1.10 is provided on the outer shell at the rear of the unit air duct 1, and a medium efficiency filter 1.9 is installed inside the air outlet 1.10.

[0024] The condensing heat circulation mechanism 2 includes a three-pipe outdoor unit 2.1 and a reheat fan 2.5. The three-pipe outdoor unit 2.1 includes a liquid supply pipe 2.2, a return air pipe 2.3 and a hot gas bypass pipe 2.4. The hot gas bypass pipe 2.4 is connected to the reheat fan 2.5. The reheat fan 2.5 is installed between the "V"-shaped two-stage evaporator 1.5 and the steam heater 1.6 in the unit air duct 1. The reheat fan 2.5 provides to the unit air duct 1.

[0025] The liquid supply pipeline 2.2 is connected to two liquid supply branches, which are respectively connected to the two evaporators of the "V"-shaped two-stage evaporator 1.5. The outlet pipelines of the two evaporators of the "V"-shaped two-stage evaporator 1.5 are respectively connected to the three-way valve 1 2.11 and the three-way valve 2 2.12. The two liquid supply branches are respectively installed with a refrigeration expansion valve 1 2.7 and a refrigeration expansion valve 2 2.9. The refrigeration expansion valve 1 2.7 is connected in parallel with a check valve 1 2.8 through a pipeline, and the refrigeration expansion valve 2 2.9 is connected in parallel with a check valve 2 2.10 through a pipeline.

[0026] The middle part of the hot gas bypass pipeline 2.4 is connected to the three-way valve 1 2.11 and the three-way valve 2 2.12 through two hot gas branches, and the three-way valve 1 2.11 and the three-way valve 2 2.12 are both connected to the return gas pipeline 2.3.

[0027] The outlet pipe of the reheating fan 2.5 is connected to the liquid supply branch pipe, and a thermal expansion valve 2.6 is installed on the outlet pipe of the reheating fan 2.5.

[0028] Embodiment 2: The specific working principle of the dual-cold-source low dew-point direct expansion dehumidification unit adopting the structural form of embodiment 1.

[0029] The utility model is characterized in that it adopts chilled water + direct evaporation refrigeration; it adopts two-stage pre-cooling and dehumidification measures of an external centralized cold source (such as a chilled water meter cold coil 1.4 with a supply and return water temperature of 7 to 12°C and a direct expansion coil ("V" type two-stage evaporator 1.5), which can achieve an outlet dew point temperature of the evaporating coil ("V" type two-stage evaporator 1.5) of 0°C, and adopts the condensation heat of the direct expansion cold source as a defrosting heat source. Its advantages are that it can not only utilize the high energy efficiency of the external centralized cold source, but also utilize the direct expansion cold source to achieve a lower dew point and more sufficient pre-cooling and dehumidification, and at the same time, it can also directly utilize the condensation heat of the direct expansion cold source as a heating source for the defrosting system on site to achieve the best comprehensive energy efficiency.

[0030] The utility model is characterized in that a three-pipe direct expansion cold source is adopted, and dual evaporators are used for alternate cooling and defrosting; two groups of evaporators with the same processing capacity are designed to be connected in parallel in the system, and when one group of evaporators cannot work normally after being frosted, the frosted evaporator is defrosted and the other group of evaporators is put into normal cooling; dual air ducts are used to achieve continuous air supply of the refrigeration system by means of air valve control and connection or isolation with the system, thereby ensuring a constant temperature and humidity environment in the air-conditioned area.

[0031] The utility model is characterized in that the condensation waste heat of the direct expansion dehumidification system is recovered and utilized to reheat the air supply, thereby reducing the heating input.

[0032] The utility model is characterized in that the condensation heat can be infinitely adjusted and input as needed; and the air supply temperature of the processed air can be accurately regulated by adjusting the fan speed.

[0033] The present utility model is not limited to the above-mentioned implementation modes, and anyone should be aware of the structural changes made under the inspiration of the present utility model. Any technical solutions that are the same or similar to the present utility model fall within the protection scope of the present utility model.

[0034] The technology, shape and structure parts not described in detail in the present invention are all known technologies.

Claims

1. A dual-cold-source low dew-point direct expansion dehumidification unit, characterized in that: It includes a unit air duct and a condensing heat circulation mechanism, wherein the unit air duct is provided with a surface cooling coil, a "V"-shaped two-stage evaporator is installed at the outlet of the surface cooling coil, a steam heater and a steam humidifier are installed at the outlet of the "V"-shaped two-stage evaporator, and a blower is installed at the rear of the steam humidifier; The condensing heat cycle mechanism includes a three-pipe outdoor unit and a reheat fan. The three-pipe outdoor unit includes a liquid supply pipe, a return air pipe and a hot gas bypass pipe. The hot gas bypass pipe is connected to the reheat fan. The reheat fan is installed between the "V"-shaped two-stage evaporator and the steam heater in the air duct of the unit.

2. The dual cold source low dew point direct expansion dehumidification unit according to claim 1 is characterized in that: A fresh air inlet is arranged on the outer shell at the front of the air duct of the unit, a primary filter is installed on the inner side of the fresh air inlet, and a surface cooling coil is installed at the outlet of the primary filter.

3. The dual cold source low dew point direct expansion dehumidification unit according to claim 2 is characterized in that: A return air inlet is also provided on the shell of the air duct of the unit, and the return air inlet is located between the surface cooling coil and the "V"-shaped two-stage evaporator.

4. The dual cold source low dew point direct expansion dehumidification unit according to claim 1 is characterized in that: An air supply port is arranged on the outer shell at the rear of the air duct of the unit, and a medium-efficiency filter is installed on the inner side of the air supply port.

5. The dual cold source low dew point direct expansion dehumidification unit according to claim 1 is characterized in that: The liquid supply pipeline is connected to two liquid supply branches, and the two liquid supply branches are respectively connected to the two evaporators of the "V"-shaped two-stage evaporator. The outlet pipelines of the two evaporators of the "V"-shaped two-stage evaporator are respectively connected to three-way valve 1 and three-way valve 2. Refrigeration expansion valve 1 and refrigeration expansion valve 2 are respectively installed on the two liquid supply branches. Refrigeration expansion valve 1 is connected in parallel with check valve 1 through a pipeline, and refrigeration expansion valve 2 is connected in parallel with check valve 2 through a pipeline.

6. The dual cold source low dew point direct expansion dehumidification unit according to claim 5, characterized in that: The middle part of the hot gas bypass pipeline is respectively connected to the three-way valve 1 and the three-way valve 2 through two hot gas branch pipes, and the three-way valve 1 and the three-way valve 2 are both connected to the return air pipeline.

7. The dual cold source low dew point direct expansion dehumidification unit according to claim 5, characterized in that: The outlet pipe of the reheating fan is connected to the liquid supply branch pipe, and a thermal expansion valve is installed on the outlet pipe of the reheating fan.

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