Two-stage two-channel heat recovery type all fresh air constant-temperature and constant-humidity air conditioning unit

Abstract

The utility model discloses a two-stage two-channel heat recovery type all-fresh-air constant-temperature and constant-humidity air conditioning unit which comprises a fresh air adjusting valve, a primary filter, a first-stage plate type heat recovery heat exchanger, a surface cooling coil, a second-stage plate type heat recovery heat exchanger, an air feeder, a medium-efficiency filter, a heating coil, a humidifier and an air supply opening which are sequentially connected on the fresh air side. The air return adjusting valve, the medium efficiency filter, the second-stage plate type heat recovery heat exchanger, the air exhaust fan, the first-stage plate type heat recovery heat exchanger and the air exhaust opening are sequentially connected to the air exhaust side; the second-stage plate type heat recovery heat exchanger comprises a fresh air side bypass ventilation opening and an exhaust side bypass ventilation opening, and a fresh air side bypass ventilation quantity adjusting valve and an exhaust side bypass ventilation quantity adjusting valve are arranged on the fresh air side bypass ventilation opening and the exhaust side bypass ventilation opening respectively. The energy recovered by the utility model is cold energy in the exhaust air and heat of the heated exhaust air, so that the energy is recovered, and the energy consumption is reduced.

Description

Technical Field

[0001] The utility model relates to a double-stage double-channel heat recovery type fresh air constant temperature and humidity air conditioning unit. Background Art

[0002] In the purification air conditioning system or constant temperature and humidity air conditioning system, the air temperature and humidity accuracy requirements are high. The air treatment needs to be cooled and dehumidified before increasing the supply air temperature to meet the requirements of industrial production or human comfort. In some special places, such as animal laboratories, negative pressure wards, etc., the indoor air needs to be completely exhausted to the outdoors, and the air conditioning system uses fresh air. At this time, the air conditioning system is operated with constant temperature and humidity of fresh air, and its operating energy consumption is quite large. In order to recover the energy in the indoor exhaust air, the air conditioning system generally uses energy recovery devices, such as coil heat recovery, plate heat recovery, three-dimensional heat pipe heat recovery, etc. But usually the first-level heat recovery type is adopted. The working principle of the ordinary first-level heat recovery system is that in summer, the high-temperature fresh air side recovers the low-temperature return air cooling capacity of the exhaust side, pre-cools the high-temperature fresh air, and reduces the cooling capacity of the main surface cooler on the fresh air side. In winter, the low-temperature fresh air side recovers the high-temperature return air heat on the exhaust side, pre-heats the low-temperature fresh air and heats it up, reducing the heat of the main heater on the fresh air side. In a constant temperature and humidity air conditioning system, in summer, after the fresh air is cooled and dehumidified by the surface cooler, it is usually heated up by the heater to a suitable air supply temperature and sent to the room, resulting in energy waste due to the offset of cold and heat. Therefore, even if the fresh air constant temperature and humidity air conditioning unit is equipped with the above-mentioned ordinary primary heat recovery device, there is still energy waste, that is, there is still room for energy recovery. Utility Model Content

[0003] In order to solve the problems of energy consumption and energy recovery limitations in the above-mentioned traditional heat recovery fresh air constant temperature and humidity units, the present invention provides a two-stage dual-channel heat recovery fresh air constant temperature and humidity air-conditioning unit.

[0004] The technical solution adopted by the utility model to solve the technical problem is: a two-stage two-channel heat recovery type fresh air constant temperature and humidity air conditioning unit, which includes a fresh air regulating valve, a primary filter, a primary plate heat recovery heat exchanger, a surface cooling coil, a secondary plate heat recovery heat exchanger, a blower, a medium efficiency filter, a heating coil, a humidifier and an air supply vent which are sequentially connected on the fresh air side; and a return air regulating valve, a medium efficiency filter, a secondary plate heat recovery heat exchanger, an exhaust fan, a primary plate heat recovery heat exchanger and an exhaust vent which are sequentially connected on the exhaust side;

[0005] The two-stage plate-type heat recovery heat exchanger comprises a fresh air side bypass vent and an exhaust air side bypass vent, on which a fresh air side bypass air volume regulating valve and an exhaust air side bypass air volume regulating valve are respectively arranged.

[0006] Furthermore, the fresh air side and the exhaust air side are arranged in two layers, the secondary plate type heat recovery heat exchanger includes a fresh air side air outlet, a fresh air side bypass air outlet, an exhaust side air outlet and an exhaust side bypass air outlet located in the upper layer; and a fresh air side air volume regulating valve, a fresh air side bypass air volume regulating valve, a fresh air side bypass vent, an exhaust side air volume regulating valve, an exhaust side bypass air volume regulating valve and an exhaust side bypass vent located in the lower layer.

[0007] Furthermore, when operating under winter conditions, the fresh air side bypass air volume regulating valve and the exhaust air side bypass air volume regulating valve of the secondary plate heat recovery heat exchanger are opened; when operating under summer conditions, the fresh air side bypass air volume regulating valve and the exhaust air side bypass air volume regulating valve of the secondary plate heat recovery heat exchanger are closed.

[0008] The beneficial effects of the utility model are as follows: the heat recovery efficiency in summer conditions is significantly improved compared with the traditional heat recovery efficiency. The new two-stage heat recovery device adds a recovery of the coldness in the low-temperature fresh air on the fresh air side after being processed by the main heat exchanger, thereby increasing the potential for recovering energy from the high-temperature fresh air. The energy recovered by the utility model is the coldness in the exhaust air and the heat of the exhaust air after being heated, so that energy is recovered and energy consumption is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0010] Figure 2 It is a top view schematic diagram of the upper structure of the utility model;

[0011] Figure 3 It is a top view schematic diagram of the lower structure of the utility model;

[0012] Figure 4 for Figure 1 AA section diagram along the middle;

[0013] Figure 5 for Figure 1 Schematic diagram of the cross-section along the middle edge BB.

[0014] In the figure: fresh air regulating valve 101, primary filter 102, primary plate heat recovery heat exchanger 103, surface cooling coil 104, secondary plate heat recovery heat exchanger 106, fresh air side air volume regulating valve I 1051, fresh air side air outlet 1052, fresh air side bypass air volume regulating valve II 1053, fresh air side bypass air outlet I1054, fresh air side bypass air outlet 1055, air supply fan 107, medium efficiency filter 108, heating coil 109, humidifier 1010, air supply air outlet 1011, return air regulating valve 201, medium efficiency filter 202, exhaust side air volume regulating valve I 2031, exhaust side air outlet 2032, exhaust side bypass air volume regulating valve II 2033, exhaust side bypass vent I2034, exhaust side bypass air outlet 2035, exhaust fan motor 204, exhaust vent 205. DETAILED DESCRIPTION

[0015] In order to better understand the present invention, Figures 1 to 5 The implementation modes of the present utility model will be explained in detail.

[0016] The utility model double-stage double-channel heat recovery type fresh air constant temperature and humidity air conditioning unit includes a fresh air side and an exhaust side. The fresh air side is sequentially provided with: a fresh air regulating valve 101, a primary filter 102, a primary plate heat recovery heat exchanger 103, a surface cooling coil 104, a secondary plate heat recovery heat exchanger 106 (with bypass function), a blower 107, a medium efficiency filter 108, a heating coil 109, a humidifier 1010 and an air supply vent 1011. The exhaust side is sequentially provided with: a return air regulating valve 201, a medium efficiency filter 202, a secondary plate heat recovery heat exchanger 106 (with bypass function), an exhaust fan motor 204, a primary plate heat recovery heat exchanger 103 and an exhaust vent 205. The two-stage plate heat recovery heat exchanger (with bypass function) in the two-stage two-channel heat recovery type fresh air constant temperature and humidity air-conditioning unit comprises a fresh air side volume regulating valve I 1051 on the lower layer, a fresh air side air outlet 1052 on the upper layer, a fresh air side bypass volume regulating valve II 1053 on the lower layer, a fresh air side bypass vent I 1054 on the lower layer and a fresh air side bypass outlet 1055 on the upper layer on the fresh air side; and an exhaust side volume regulating valve I 2031 on the lower layer, an exhaust side air outlet 2032 on the upper layer, an exhaust side bypass volume regulating valve II 2033 on the lower layer, an exhaust side bypass vent I 2034 on the lower layer and an exhaust side bypass outlet 2035 on the upper layer on the exhaust side.

[0017] Operation scheme of this new product: In summer cooling and dehumidification conditions, it is assumed that the summer fresh air is 34℃, and the temperature in the constant temperature and humidity room is 24℃, that is, the exhaust air is 24℃. The process of summer cooling and dehumidification is as follows: After the 34℃ high-temperature and high-humidity fresh air passes through the fresh air primary filtration, the primary plate heat recovery heat exchanger 103 exchanges cold with the 18℃ low-temperature exhaust air on the exhaust side, and cools it to 23℃ (the heat recovery efficiency is designed to be 65%). After cooling and dehumidifying to the indoor dew point of 12℃ by the main heat exchanger 104, the low-temperature and low-humidity air passes through the fresh air side air volume regulating valve I1051 through the secondary plate heat recovery heat exchanger. At this time, the bypass ventilation valves 1053 and 2033 of the secondary plate heat recovery heat exchanger are both closed, the bypass air ducts on both sides are blocked, and the exhaust regulating valve 2031 on the exhaust side is opened. Therefore, all fresh air and exhaust air pass through the secondary plate heat recovery heat exchanger for secondary heat exchange. The low-temperature air of 12℃ exchanges heat with the exhaust air of 24℃. The fresh air is heated to 20℃ (the heat recovery efficiency is designed to be 65%). The high-temperature and low-humidity fresh air of 20℃ is further heated and fine-tuned according to the indoor supply air temperature requirements. According to the supply air temperature difference of 2-3℃, the supply air temperature is 21-22℃, that is, the secondary reheating only needs to increase the temperature by 1-2℃. The energy-saving effect of this scheme: the 34℃ high-temperature and high-humidity fresh air is cooled to 24℃ by the primary plate heat recovery heat exchanger, cooled and dehumidified to 12℃ by the main cold coil, heated to 20℃ by the secondary plate heat recovery heat exchanger, and then fine-tuned according to the indoor needs for supply air. The primary plate heat recovery saves about 39% energy, and the secondary plate heat recovery saves about 80% energy. Compared with ordinary primary plate heat recovery, the secondary plate heat recovery solution increases the reheat heat recovery efficiency by 80%. This heat recovery can greatly reduce or completely replace reheating and improve the overall energy saving efficiency of the product.

[0018] When operating in winter, the secondary plate heat recovery heat exchanger in this scheme does not operate, and the fresh air and exhaust air on both sides are bypassed through the bypass duct to reduce the resistance in the system. The airflow operation process is as follows: In the winter heating and humidification operating conditions, it is assumed that the fresh air in winter is 0℃, and the temperature in the constant temperature and humidity room is still 24℃, that is, the exhaust air is 24℃. The process of winter heating and humidification is as follows: After the 0℃ low-temperature and low-humidity fresh air passes through the fresh air primary filtration, the primary plate heat recovery heat exchanger 103 exchanges heat with the 24℃ high-temperature exhaust air on the exhaust side, and the temperature is raised to 15℃ (the heat recovery efficiency is designed to be 65%). The fresh air passes through the surface cooling coil (the surface cooling coil is closed and not running at this time), the secondary plate heat recovery heat exchanger is closed, and the fresh air passes through the bypass duct on the heat recovery side, and is sent to the heating coil 109 by the blower 107 and heated to 27℃. After that, it is humidified by the humidifier to the required air supply state point indoors, and then supplied to the indoors. Bypass process of the two-stage plate heat recovery heat exchanger: fresh air side: the air volume regulating valve I 1051 on the fresh air side of the lower layer is closed, and the bypass air volume regulating valve II 1053 on the fresh air side of the lower layer is opened, and the fresh air flows from the lower layer through the bypass air duct from the bypass vent I 1054 into the bypass air duct on the upper layer, and then flows into the fresh air supply fan 107 through the bypass air vent II 1055 on the fresh air side of the upper layer; exhaust air side: the exhaust air side air volume regulating valve I 2031 on the exhaust air side of the lower layer is closed, and the bypass air volume regulating valve II 2033 on the exhaust air side of the lower layer is opened, and the exhaust air flows from the lower layer through the bypass air duct from the bypass vent I 2034 into the bypass air duct on the upper layer, and then flows into the exhaust air supply fan 204 through the bypass air vent II 2035 on the exhaust air side. The bypass of the entire new exhaust air is completed, and the secondary plate heat recovery heat exchanger is not used for bypass, which can reduce the resistance of the secondary plate heat recovery heat exchanger, thereby reducing the power consumption of the supply and exhaust fans. At this time, the two-stage heat recovery has the same function as the traditional one-stage heat recovery.

[0019] If instructions are required, technicians in this field can make adaptive adjustments to the components on the fresh air side or the exhaust air side as needed, such as adding or reducing a certain component. These conventional replacement changes also fall within the scope of protection of the present utility model.

Claims

1. A two-stage, two-channel heat recovery type fresh air constant temperature and humidity air conditioning unit, characterized in that: It includes a fresh air regulating valve, a primary filter, a primary plate heat recovery heat exchanger, a surface cooling coil, a secondary plate heat recovery heat exchanger, a blower, a medium-efficiency filter, a heating coil, a humidifier and an air supply vent which are sequentially connected on the fresh air side; and a return air regulating valve, a medium-efficiency filter, a secondary plate heat recovery heat exchanger, an exhaust fan, a primary plate heat recovery heat exchanger and an exhaust vent which are sequentially connected on the exhaust air side; The two-stage plate-type heat recovery heat exchanger comprises a fresh air side bypass vent and an exhaust air side bypass vent, on which a fresh air side bypass air volume regulating valve and an exhaust air side bypass air volume regulating valve are respectively arranged.

2. The two-stage two-channel heat recovery type fresh air constant temperature and humidity air conditioning unit as described in claim 1, characterized in that: The fresh air side and the exhaust air side are arranged up and down, and the two-stage plate-type heat recovery heat exchanger includes a fresh air side air outlet, a fresh air side bypass air outlet, an exhaust side air outlet and an exhaust side bypass air outlet located on the upper layer; and a fresh air side air volume regulating valve, a fresh air side bypass air volume regulating valve, a fresh air side bypass vent, an exhaust side air volume regulating valve, an exhaust side bypass air volume regulating valve and an exhaust side bypass vent located on the lower layer.

3. The two-stage two-channel heat recovery type fresh air constant temperature and humidity air conditioning unit as described in claim 1, characterized in that: When operating in winter conditions, the fresh air side bypass air volume regulating valve and the exhaust air side bypass air volume regulating valve of the secondary plate type heat recovery heat exchanger are opened; when operating in summer conditions, the fresh air side bypass air volume regulating valve and the exhaust air side bypass air volume regulating valve of the secondary plate type heat recovery heat exchanger are closed.

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