Efficient condenser with air outlet temperature higher than 100 DEG C for CO2 heat pump dryer

Abstract

The utility model relates to the technical field of heat energy conversion and utilization, in particular to an efficient condenser for a CO2 heat pump dryer with the air outlet temperature larger than 100 DEG C. The efficient condenser is an n-unit copper pipe aluminum fin heat exchange cooling combination and comprises a CO2 high-temperature air inlet pipe and a CO2 return air collecting pipe, and a heat exchange stage, an expansion buffer chamber and a cooling stage are arranged between the CO2 high-temperature air inlet pipe and the CO2 return air collecting pipe. The structural mode is Hm + Ri + Ln. The heat exchange device can effectively carry out heat exchange on natural working medium CO2 and air, and is used for heating to generate high-temperature air with the temperature of more than 100 DEG C; according to the device, heat exchange can be efficiently carried out on supercritical high-temperature and high-pressure CO2 gas and air, the CO2 gas after heat exchange can be effectively cooled, the efficiency of a CO2 heat pump system is greatly improved, and therefore the energy utilization rate is improved, and the device is simple in structure, convenient to combine, convenient to produce and suitable for being used for drying small, medium and large CO2 heat pumps.

Description

Technical Field

[0001] This utility model belongs to the field of heat energy conversion and utilization technology, specifically a high-efficiency condenser for CO2 heat pump dryer with an outlet air temperature greater than 100℃. Background Technology

[0002] With the continuous expansion of industrial and agricultural scale and the development of emerging industries, the emission of waste gases and greenhouse gases in countries around the world is rapidly increasing, posing a serious threat to the living environment of people worldwide. CO2 heat pumps, using natural CO2 as a refrigerant, possess excellent environmental characteristics, effectively controlling ozone layer depletion, reducing greenhouse gas production, exhibiting good high-temperature drying performance, and saving energy, thus achieving more efficient, energy-saving, and clean drying. The high-efficiency operation of the system's supercritical cycle will be the future direction of development in this field. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of the existing technology by providing a high-efficiency condenser for CO2 heat pump dryers with an outlet air temperature greater than 100°C. This heat exchange device can effectively exchange heat between the natural working fluid CO2 and air, generating high-temperature air above 100°C. The device can efficiently exchange heat between supercritical high-temperature, high-pressure CO2 gas and air, and effectively cool the CO2 gas after heat exchange, greatly improving the efficiency of the CO2 heat pump system and thus increasing energy utilization. Furthermore, it has a simple structure, is easy to assemble, convenient to produce, and suitable for small, medium, and large-scale CO2 heat pump drying applications.

[0004] The specific technical solution adopted by this utility model is as follows:

[0005] A high-efficiency condenser for a CO2 heat pump dryer with an outlet air temperature greater than 100℃ includes a high-temperature CO2 inlet pipe and a CO2 return gas manifold. A heat exchange stage, an expansion buffer chamber, and a cooling stage are arranged between the high-temperature CO2 inlet pipe and the CO2 return gas manifold. The structural configuration is Hm+R. i +Ln,

[0006] Heat exchange stage Hm: multi-stage series, where m is the number of series stages. Each stage Hm has at least one heat exchange unit, and the heat exchange units are connected in parallel.

[0007] Expansion Buffer Chamber R i An expansion buffer chamber is cyclically installed between every two air heat exchange stages, that is, between every two heat exchange stages, every two cooling stages, or between a heat exchange stage and a cooling stage.

[0008] Cooling stage Ln: multi-stage series, where n is the number of series stages, each stage Ln has at least one heat exchange unit, and the heat exchange units are connected in parallel;

[0009] Value range: m, i, n are positive integers, n ≥ 1, i ≥ 1, m ≥ n.

[0010] Preferably, the heat exchange unit includes an intake air diversion pipe unit and a return air manifold pipe unit. Each intake air diversion pipe unit is connected in parallel, each return air manifold pipe unit is connected in parallel, and the diversion pipe unit and the return air manifold pipe unit are connected in series to form a combined structure in parallel and in series.

[0011] Preferred configuration: The cooling stage and the heat exchange stage have different heat exchange areas for each stage. The air flows from the low-temperature side to the high-temperature side. The cooling stage has the largest area, and the area of ​​each heat exchange stage is larger than that of the next heat exchange stage.

[0012] The technical effects achieved by this utility model are as follows:

[0013] This invention provides a high-efficiency condenser for CO2 heat pump dryers with an outlet air temperature greater than 100℃. It is a heat exchange device that can effectively exchange heat between the natural working fluid CO2 and air, and is used to heat and generate high-temperature air above 100℃. This device can efficiently exchange heat between supercritical high-temperature and high-pressure CO2 gas and air, and can effectively cool the CO2 gas after heat exchange, greatly improving the efficiency of the CO2 heat pump system, thereby improving energy utilization. It also has a simple structure, is easy to assemble, is easy to produce, and is suitable for small, medium and large CO2 heat pump dryers. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the principle of the high-efficiency condenser of this utility model.

[0015] Figure 2 This is a diagram showing the distribution of CO2 temperature and air temperature in the heat exchanger of this invention.

[0016] The attached diagram lists the components represented by each number as follows:

[0017] 1. High-temperature CO2 inlet pipe; 2. CO2 return gas manifold; 3. Low-temperature air inlet side; 4. High-temperature air outlet side; 5. First expansion buffer chamber; 6. Second expansion buffer chamber; 7. Inlet gas diversion manifold; 8. Return gas manifold; 9. Heat exchange unit; H1-First heat exchange stage, H2-Second heat exchange stage, L-Cooling stage. Detailed Implementation

[0018] To make the objectives and advantages of this utility model clearer, the present utility model will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the following text is only used to describe one or more specific embodiments of this utility model and does not strictly limit the scope of protection specifically claimed by this utility model.

[0019] This invention provides a high-efficiency condenser for a CO2 heat pump dryer with an outlet air temperature greater than 100℃. It is an n-unit copper tube and aluminum fin heat exchange and cooling combination with a structural mode of Hm+R. i +Ln, heat exchange stage Hm: multi-stage series connection, where m is the number of stages in series. Each stage Hm has at least one heat exchange unit, and the heat exchange units are connected in parallel. Expansion buffer chamber R i Between every two air heat exchange stages or cooling stages, an expansion buffer chamber is cyclically set up, i≥1; Cooling stage Ln: Each stage Ln has at least one set of heat exchange units, the heat exchange units are connected in parallel, and there are multiple series stages Ln, where n is the number of series stages, and the value range is: n ≥1, m, i, and n are positive integers, and m≥n are satisfied at the same time.

[0020] Specifically, one embodiment is given, such as Figure 1 As shown, it includes a first heat exchange stage H1, a second heat exchange stage H2, and a cooling stage L. A first expansion buffer chamber 5 is provided between the first heat exchange stage H1 and the second heat exchange stage H2, and a second expansion buffer chamber 6 is provided between the second heat exchange stage H2 and the cooling stage L.

[0021] Preferably, the first heat exchange stage H1 includes a set of heat exchange units 9, the second heat exchange stage H2 includes two sets of heat exchange units 9 connected in parallel, and the cooling stage L includes three sets of heat exchange units 9 connected in parallel.

[0022] In practical use, the number of parallel heat exchange stages, which is also the number of heat exchange units, increases the CO2 flow rate and heat exchange time. At the same time, the heat exchange area increases, and the adjustment and combination of its heat exchange capacity is convenient, flexible, and highly practical.

[0023] In practical use, the number of parallel cooling stages, that is, the number of heat exchange units 9, increases the number of stages, which reduces the CO2 flow rate, increases the cooling time, and lowers the CO2 outlet temperature. At the same time, it depends on the air velocity; a higher air velocity results in better cooling. The adjustment and combination of the cooling stages are convenient, flexible, and highly practical.

[0024] In practical use, an expansion buffer chamber is cyclically set between every two air heat exchange stages, that is, between every two heat exchange stages, every two cooling stages, or between a heat exchange stage and a cooling stage. When air is introduced, the heat exchange area is concentrated in the middle area. Through the expansion buffer chamber, the temperature difference and wind speed of the upper air heat exchange can be mixed, reducing the wind pressure resistance caused by the air expansion of the upper heat exchange stage and increasing the heat exchange area of ​​the lower stage.

[0025] Furthermore, the CO2 parallel and series condenser includes an inlet gas distribution manifold 7, a return gas manifold 8, copper bushings, and corresponding connectors, all of which are commercially available products and assembled as needed. The connection relationship on the CO2 side is that the inlet gas distribution manifold 7 of the heat exchange stage is connected to the copper tube inlet of the aluminum fins of the heat exchange stage, and then the return gas manifold 8 is connected to the inlet of the gas distribution manifold of the cooling stage.

[0026] Furthermore, in the cooling stage and the heat exchange stage, the heat exchange area of ​​each stage is not the same. The air flows from the low temperature side to the high temperature side, and the area of ​​the cooling stage is the largest. The area of ​​each heat exchange stage is larger than the area of ​​the next heat exchange stage.

[0027] In practical application, the condenser's series structure is configured as Hm+Ri+Ln. The slower CO2 flow rate in the heat exchange stage facilitates heat exchange, while the faster airflow in the cooling stage facilitates cooling. This structural combination fully meets the heat exchange performance requirements of the heat exchanger in the CO2 heat pump system for CO2 gas and air, significantly improving the heat exchange capacity of the heat exchanger.

[0028] In practical use, the heat exchange process of the CO2 medium inside the pipe takes place in the supercritical region, and the good temperature glide matching is conducive to the heat exchange between CO2 and air, making it suitable for CO2 heat pump systems.

[0029] In practical use, the CO2 gas and air flow in opposite directions to exchange heat, achieving one-time air heating, and the outlet air temperature can reach over 100℃.

[0030] In practical use, the thermodynamic features of this utility model are as follows: the high-temperature and high-pressure CO2 gas compressed by the compressor enters the distribution row through the pipeline, and enters the parallel copper tube aluminum fin heat exchanger of the Hm stage for heat exchange. After cooling, the CO2 gas merges and enters the next stage distribution row until it enters the Ln cooler for cooling. The cooled liquid or subcritical gas CO2 merges and exits the heat exchanger.

[0031] In practical applications, the parallel and series copper tube aluminum finned heat exchangers of this invention can be used in CO2 heat pump systems or heat exchange systems for high-temperature and high-pressure gases and air.

[0032] In practical use, this utility model enables the CO2 parallel and series copper tube aluminum fin heat exchanger to perform staged heat exchange and cooling. The working fluid CO2 is distributed and discharged to the parallel stage, and the number of heat exchange units increases the disturbance of CO2 gas in the tube, making the heat exchange more complete.

[0033] The working principle of this utility model is as follows:

[0034] Figure 1As shown, it is a three-stage (heat exchange stage H1 + heat exchange stage H2 + cooling stage L1) and two-chamber (expansion buffer chamber R1 + expansion buffer chamber R2) structure, with the CO2 refrigerant and air flowing in a counter-current heat exchange manner; on the air side: the low-temperature air inlet side passes through the CO2 cooling stage, which has the largest area and a fast air inlet side wind speed, resulting in good cooling effect; it enters the first expansion buffer chamber 5, reducing the expansion wind pressure resistance and the mixed heat exchange temperature difference, and expanding the air heat exchange area of the lower stage; when entering the lower heat exchange stage, the air wind speed decreases, and it enters the second expansion buffer chamber 6, reducing the expansion wind pressure resistance of the upper stage and the mixed heat exchange temperature difference, and expanding the air heat exchange area of the lower stage; when entering the high-temperature heat exchange stage, due to the decrease in wind speed at each heat exchange stage, it meets the heat exchange performance requirements of CO2 gas and air, greatly increasing the heat exchange capacity of the heat exchanger, and the outlet air temperature can reach above 100°C.

[0035] In this application example (Hm + R i + Ln); m = 2, i = 2, n = 1, and the areas are H1 < H2 < L1;

[0036] Table 1 shows the working parameters with an outlet air temperature of 103°C in the embodiment:

[0037]

[0038] The distribution of CO2 gas and air temperatures in the heat exchanger when the outlet air temperature is 103°C is as Figure 2 shown;

[0039] It can be seen from the above embodiments that the high-efficiency condenser of the CO2 heat pump dryer designed by this utility model has an outlet air temperature greater than 100°C, which can effectively meet the requirements of the outlet air temperature.

[0040] The above is only the preferred implementation mode of this utility model. It should be noted that for those of ordinary skill in the art, without departing from the principle of this utility model, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of this utility model. The structures, devices, and operation methods not specifically described and explained in this utility model, unless otherwise specified and limited, are implemented according to the conventional means in the art.

Claims

1. A high-efficiency condenser for a CO2 heat pump dryer with an outlet air temperature greater than 100°C, comprising a high-temperature CO2 inlet pipe and a CO2 return gas manifold, characterized in that, A heat exchange stage, an expansion buffer chamber, and a cooling stage are installed between the CO2 high-temperature inlet pipe and the CO2 return manifold, with a structural configuration of Hm+R. i +Ln, Heat exchange stage Hm: multi-stage series, where m is the number of series stages. Each stage Hm has at least one heat exchange unit, and the heat exchange units are connected in parallel. Expansion Buffer Chamber R i An expansion buffer chamber is cyclically installed between every two air heat exchange stages, that is, between every two heat exchange stages, every two cooling stages, or between a heat exchange stage and a cooling stage. Cooling stage Ln: multi-stage series, where n is the number of series stages, each stage Ln has at least one heat exchange unit, and the heat exchange units are connected in parallel; Value range: m, i, n are positive integers, n ≥ 1, i ≥ 1, m ≥ n.

2. The high-efficiency condenser for a CO2 heat pump dryer with an outlet air temperature greater than 100℃ according to claim 1, characterized in that: The heat exchange unit includes an intake air diversion pipe unit and a return air manifold pipe unit. Each intake air diversion pipe unit is connected in parallel, each return air manifold pipe unit is connected in parallel, and the diversion pipe unit and the return air manifold pipe unit are connected in series to form a combined structure in parallel and in series.

3. The high-efficiency condenser for a CO2 heat pump dryer with an outlet air temperature greater than 100℃ according to claim 1, characterized in that: The cooling stage and the heat exchange stage have different heat exchange areas. The air flows from the low temperature side to the high temperature side. The cooling stage has the largest area, and the area of ​​each heat exchange stage is larger than that of the next heat exchange stage.

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