CN220436683U - A rural household cold storage air conditioning system based on low-temperature grain storage - Google Patents

Abstract

The utility model discloses a rural household cold storage air conditioning system based on low-temperature grain storage, which includes a double suction port compressor, a condenser, a liquid storage device, two evaporators, a phase change cold storage tank, two electronic expansion valves, seven A solenoid valve and three fans; the double suction port compressor, condenser, first solenoid valve, liquid reservoir, first electronic expansion valve, first evaporator, and first fan form a daily cooling branch; The double suction port compressor, condenser, first solenoid valve, liquid reservoir, second electronic expansion valve, phase change cold storage tank, third solenoid valve, second evaporator, second fan, and fourth solenoid valve , the sixth solenoid valve forms the grain storage and cooling branch circuit. The utility model realizes flexible switching between various working conditions by adjusting the on-off of each branch solenoid valve, and realizes the distribution between the evaporator cooling supply and cold storage by adjusting the on-off of the evaporator and each branch solenoid valve, solving the problem This solves the problem that the existing cold storage device of the air conditioning water system cannot be directly applied to the refrigerant system.

Description

A rural household cold storage air conditioning system based on low-temperature grain storage

Technical field

The utility model relates to a rural household cold storage air conditioning system based on low-temperature grain storage, and belongs to the technical field of grain storage systems.

Background technique

Relevant surveys show that the loss rate of grain storage by farmers in my country is about 8%-12%. There are many rodent and mold infestations, few protective measures, poor storage technical conditions, and large losses of stored grains. The improvement of farmers' grain storage technology is a key measure to solve the problem of grain storage loss and improve the quality of grain storage. Low-temperature storage of grain is a recognized scientific and pollution-free way of storing grain. Low temperature can slow down the metabolism of grain particles, inhibit the growth of insects, molds and microorganisms and effectively reduce the loss of stored grains; it can also reduce drug fumigation pollution and has a significant effect on delaying the aging of grain quality. Relevant research shows that household air conditioners can achieve the effect of low-temperature grain storage. However, on the one hand, due to my country's increasingly tight power supply situation, especially in high-temperature seasons, it is difficult to ensure continuous power supply in rural areas, which will lead to problems such as air-conditioning power outages, delayed cooling of stored grains, and grain mildew. On the other hand, during high temperatures, the COP of air-conditioning operation is reduced and the operating costs are high. The benefits of low-temperature grain storage will be seriously offset. Therefore, it is difficult for farmers to directly use conventional household air conditioners for low-temperature grain storage.

Low-temperature grain storage is an effective way to improve the quality of stored grain. However, low-temperature grain storage technology suitable for farmers and the supporting small refrigeration equipment are not yet mature and cannot be widely used in farmers' grain storage. Small air-conditioning systems combined with cold storage are one of the main ways to realize this technology. my country's air-conditioning thermal storage technology can be divided into four methods according to different thermal storage media: water thermal storage, ice thermal storage, eutectic salt thermal storage and gas compound thermal storage.

Water cold storage uses the sensible heat of water to store cold energy, that is, using low-temperature water of 4-7°C for cold storage. It has the obvious advantages of saving investment, low technical requirements, low maintenance costs, and can use conventional air conditioning and refrigeration units. However, at the same time, shortcomings such as large floor space, large cooling loss, and troublesome waterproofing and insulation are also problems that cannot be ignored. This results in the application of water storage air conditioning systems being restricted in large cities with dense populations and high land utilization rates.

Ice storage uses the latent heat of phase change of ice to store cold energy. To store the same amount of cold energy, the volume of the medium required for ice storage is much smaller than that of water storage. Its storage density is large and the cold storage temperature is almost constant, making it easy to store. However, the low evaporation temperature of the refrigeration unit will lead to a reduction in the performance coefficient of the compressor.

Eutectic salt is a phase change material, and its cold storage material has a higher phase change temperature, which greatly improves the efficiency of the host. When eutectic salt is used for cold storage, the insulation of the thermal insulation tank can be reduced. However, the component separation phenomenon of the eutectic salt cold storage material during the cold storage and cooling process is an important problem.

Gas compound thermal storage is an emerging thermal storage air-conditioning technology. Its thermal storage temperature is consistent with the operating conditions of the air conditioner. It has high thermal storage density and high heat transfer efficiency during thermal storage and cooling. Because it is an emerging technology, there are still a series of core technical issues that need to be urgently needed. solve.

Utility model content

The technical problem to be solved by this utility model is: to overcome the shortcomings of the existing technology, provide a rural household cold storage air conditioning system based on low-temperature grain storage, use phase change cold storage materials with higher phase change temperatures to achieve cold storage, and avoid ice The shortcomings of cold storage and water cold storage equipment can not only meet people's daily cooling needs, but also air-condition and supply air to the grain storage space to achieve low-temperature grain storage.

The technical solutions adopted by this utility model to solve the technical problems are as follows:

A rural household cold storage air conditioning system based on low-temperature grain storage, including a double suction port compressor, a condenser, a liquid receiver, a first evaporator, a phase change cold storage tank, a second evaporator, a first electronic expansion valve, a third Two electronic expansion valves, a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, a first fan, a second fan and a third Fan; the double suction port compressor, condenser, first solenoid valve, liquid reservoir, first electronic expansion valve, first evaporator, and first fan form a daily cooling branch; the double suction port Composed of compressor, condenser, first solenoid valve, liquid reservoir, second electronic expansion valve, phase change cold storage tank, third solenoid valve, second evaporator, second fan, fourth solenoid valve, and sixth solenoid valve Grain storage and cooling branch.

The double suction port compressor and the condenser are connected by a pipeline, which is used to compress the refrigerant and generate high-temperature and high-pressure gas; the condenser and the liquid storage are connected by a pipeline, which is used to compress the compressed gas. The gas generated by machine compression is cooled; the liquid reservoir is connected to the first evaporator and the second evaporator respectively through pipelines for storing high-pressure liquid from the condenser; the liquid reservoir is connected to the first evaporator and the second evaporator. The first electronic expansion valve and the second electronic expansion valve are respectively connected by pipelines for regulating flow and controlling superheat; the first electronic expansion valve is connected to the first evaporator and the second electronic expansion valve through pipelines. The electronic expansion valve is connected to the second evaporator through a pipeline, and is used to evaporate the low-temperature refrigerant coming out of the electronic expansion valve under low pressure; the phase change cold storage tank is connected to the second evaporator through a pipeline, Used to release the refrigerant in the phase change cold storage box; the first evaporator and the first fan are mechanically connected, and the second evaporator and the second fan are mechanically connected for cooling or heating. ;Each solenoid valve is set on the connecting pipe to control the flow of fluid.

The phase change cold storage box is composed of an evaporation coil and a phase change material. The phase change temperature of the phase change material is higher than the evaporation temperature of the air conditioner. The phase change material is packaged outside the evaporation coil to form an independent phase change cold storage box. , the process of cold storage and cold release can be realized through the heat transfer of the evaporation coil in the box.

The phase change material is ZJ-PCM-A paraffin inorganic salt.

This utility model takes the grain storage of rural farmers as the research background, takes small-scale cold storage air conditioners as the research object, and combines phase change cold storage technology to comprehensively consider daily cooling and stored grain cooling, fully utilizing the stored cold energy in different usage scenarios, and improving It improves the utilization rate and operating efficiency of air conditioners and reduces system energy consumption.

In the present utility model, after the refrigerant is compressed by the compressor and condensed by the condenser, it enters the two evaporation branches. One of the branches is used for daily cooling, and a higher evaporation temperature can be used (compressor-condenser-liquid reservoir-first evaporator); the other branch corresponds to grain storage for cooling or cold storage device, comparison It is suitable to use a lower evaporation temperature (compressor - condenser - liquid reservoir - phase change cold storage tank - second evaporator). Use a new phase change material with a phase change temperature higher than the evaporation temperature of the air conditioner and encapsulate it in the evaporation plate. Outside the tube, an independent phase change cold storage box is formed, and the cold storage and cold release processes can be realized through the heat transfer of the coil inside the box.

In the cold storage process, the evaporation coil takes away the heat of the phase change material through the lower temperature refrigerant to achieve cold storage; in the cold release process, the evaporation coil in the phase change cold storage box is connected to the evaporator in the granary, and the refrigerant between the two The on and off is controlled by a solenoid valve. When the solenoid valve is opened, the liquid refrigerant in the cold storage box flows into the evaporator under the action of gravity, and cooperates with the evaporator fan to exchange heat with the indoor air to achieve cooling. The gaseous refrigerant has a lower density and flows back to the cold storage box under the action of gravity. It exchanges heat with the phase change material in the box and then condenses. It re-enters the granary evaporator and exchanges heat to evaporate, forming a cycle.

The positive beneficial effects of this utility model are as follows:

1. This utility model takes the grain storage of rural farmers as the research background, takes small-scale cold storage air conditioners as the research object, combines electric energy and phase change cold storage technology, and takes overall consideration of daily cooling and grain storage to fully utilize the cold storage in different applications. Usage scenarios improve the utilization rate and operating efficiency of air conditioners and reduce system energy consumption.

2. This utility model uses a new phase change material with a phase change temperature higher than the evaporation temperature of the air conditioner. It is packaged outside the evaporation coil to form an independent phase change cold storage box. The cold storage and release are realized through the heat transfer of the coil in the box. Cooling process: A. The cold storage process is realized through the phase change cold storage box connected in parallel with the evaporator 1. Two parallel refrigerant branches are set up after the conventional split air conditioner condenser. Under the control of the solenoid valve and expansion valve of each branch, the refrigerant branches flow to the evaporator 1 and the refrigerant branch containing the phase change cold storage tank respectively to achieve cold storage. . B. The cooling process is realized through the phase change cold storage box and the evaporator 2 connected to it. The refrigerant in the connecting pipeline is controlled by the solenoid valve. When the solenoid valve is opened, the liquid refrigerant in the cold storage box is controlled by gravity. It flows downward into the evaporator 2, and exchanges heat with the air through the fan 2 to complete the cooling. C. The independent cooling of the daily room passes through another refrigerant branch, and the evaporator 1 and the matching fan 1 complete the heat exchange with the daily air-conditioned room. When the cold storage box stores cold energy, the evaporator 1 will The refrigerant is subcooled to improve operating efficiency.

3. This utility model realizes flexible switching between working conditions by adjusting the on-off of each branch solenoid valve, and realizes the distribution between evaporator cooling and cold storage by adjusting the on-off of the evaporator and each branch solenoid valve. , which solves the problem that the existing cold storage device of the air conditioning water system cannot be directly applied to the refrigerant system.

4. This utility model adopts a refrigerant gravity circulation cooling storage/cooling release device. During a power outage, the cooling process can be completed by relying on the gravity of the refrigerant itself, which is more energy-saving and more suitable for rural areas.

Description of drawings

Figure 1 is a schematic structural diagram of the utility model;

Figure 2 is a schematic diagram of the connection of each component in the present utility model.

Figure 3 is a schematic structural diagram of the phase change cold storage box of the present utility model.

Detailed ways

The utility model will be further explained and described below in conjunction with the accompanying drawings:

Referring to Figure 1, a rural household cold storage air conditioning system based on low-temperature grain storage is characterized in that: the rural household solar cold storage air-conditioning system based on low-temperature grain storage includes a double suction port compressor 1, a condenser 2, and a liquid reservoir. 3. First evaporator 4, phase change cold storage tank 5, second evaporator 6, first electronic expansion valve 7, second electronic expansion valve 8, first solenoid valve 9, second solenoid valve 10, third solenoid valve 11. The fourth solenoid valve 12, the fifth solenoid valve 13, the sixth solenoid valve 14, the seventh solenoid valve 15, the first fan 16, the second fan 17 and the third fan 18; double suction port compressor 1, condensation 2, the first solenoid valve 9, the liquid reservoir 3, the first electronic expansion valve 7, the first evaporator 4, and the first fan 16 form the daily cooling branch; double suction port compressor 1, condenser 2, First solenoid valve 9, liquid reservoir 3, second electronic expansion valve 8, phase change cold storage tank 5, third solenoid valve 11, second evaporator 6, second fan 17, fourth solenoid valve 12, sixth solenoid Valve 14 forms a grain storage and cooling branch.

The double suction port compressor 1 and the condenser 2 are connected by a pipeline and are used to compress the refrigerant and generate high-temperature and high-pressure gas; the condenser 2 and the liquid receiver 3 are connected by a pipeline and are used to compress the compressor. The generated gas is cooled; the liquid reservoir 3 is connected to the first evaporator 4 and the second evaporator 6 respectively through pipelines for storing high-pressure liquid from the condenser; the liquid reservoir 3 is connected to the first electronic expansion valve 7. The second electronic expansion valve 8 is connected with pipelines respectively for adjusting the flow rate and controlling the superheat; the first electronic expansion valve 7 is connected to the first evaporator 4 through pipelines, and the second electronic expansion valve 8 is connected to the first evaporator 4 through pipelines. The pipeline is connected to the second evaporator 6, which is used to evaporate the low-temperature refrigerant coming out of the electronic expansion valve under low pressure; the pipeline is connected between the phase change cold storage box 5 and the second evaporator 6, which is used to evaporate the phase change cold storage box The refrigerant realizes cooling; the first evaporator 4 and the first fan 16 are mechanically connected, and the second evaporator 6 and the second fan 17 are mechanically connected for cooling or heating; each solenoid valve is set at the connection On pipes, used to control the flow of fluids.

Referring to Figure 3, the phase change cold storage box 5 is composed of an evaporation coil and a phase change material. The phase change temperature of the phase change material is higher than the evaporation temperature of the air conditioner. The phase change material is packaged outside the evaporation coil to form an independent phase change cold storage. The cold storage and cooling process can be realized through the heat transfer of the evaporation coil in the box.

The phase change material is ZJ-PCM-A paraffin inorganic salt. Because paraffin inorganic salt phase change materials have the advantages of safety, non-toxicity, high latent heat of phase change, low price, and a variety of phase change temperatures to choose from. ZJ-PCM-A paraffin inorganic salt is selected as the cold storage material. Its phase change latent heat cPCM is 220kJ/kg. The measured solidification temperature is about 8℃, which is slightly higher than the refrigerant evaporation temperature (4.5℃ in this work). The continuous supply The mass of phase change cold storage material required for cooling for 15 minutes is 29kg.

The utility model mainly includes conventional air conditioning system components (evaporator, condenser, compressor, electronic expansion valve, etc.) plus a phase change cold storage tank, a fan, etc. Among them, the compressor adopts a double suction port compressor to cope with the different evaporation pressures of the respective refrigerant branches in the daily cooling and grain storage parts, and can also reduce the energy loss caused by the mixing of different pressures. By adjusting the on-off of the solenoid valves of the evaporator and each branch, and the opening of the electronic expansion valve, the distribution between the evaporator cooling and "multi-cooling" cooling storage is realized; by adjusting the on-off of the refrigerant circuit solenoid valve and the matching fan speed, and controls the opening of the electronic expansion valve according to the degree of superheat, controlling the amount of cooling released by the "multiple cold passages" corresponding to different working conditions.

Referring to Figure 2, flexible switching between various working conditions is achieved by adjusting the on-off of the solenoid valves in each branch. By adjusting the on-off of the evaporator and the solenoid valves of each branch, the distribution between the evaporator cooling supply and the cold storage can be realized; according to different needs, daily cooling and grain storage cold storage, separate cold storage of the grain storage part, and daily separate cooling can be realized. There are five different working conditions: cooling (can be supercooled), separate cooling of the grain storage part, and simultaneous cooling of the daily and grain storage parts. The control strategies are shown in Table 1.

① Working condition 1: Daily cooling and grain storage cold storage mode: The daily cooling load of the air-conditioned room is completely borne by the evaporator 1, and the phase change cold storage box 5 is in a cold storage state.

② Working condition 2: Simultaneous cooling of daily and grain storage: The daily cooling load of the air-conditioned room is completely borne by evaporator 1, the cooling load of the grain storage room is mainly borne by phase change cold storage box 5, and the excess cooling load is borne by evaporator 2.

③Working condition 3: Daily independent cooling (can be supercooled) mode: The daily cooling load of the air-conditioned room is borne by evaporator 1. The cold storage in the phase change storage box 5 supercools the refrigerant entering the evaporator 1, reducing the cooling load entering the evaporator. Refrigerant temperature of evaporator 1.

④ Working condition 4: Separate cooling mode for the grain storage part: The cooling load of the grain storage room is mainly borne by the cold storage in the phase change cold storage box 5, and the excess cooling load can be borne by the evaporator 2.

⑤ Working condition 5: Separate cold storage mode of the grain storage part: the phase change cold storage box 5 is in the cold storage state, and the required cooling capacity is borne by the evaporator 2.

Table 1 shows the specific control methods under five working conditions:

The working principle is as follows: the refrigerant is compressed by the compressor, condensed by the condenser, and then enters the two evaporation branches. One branch is used for daily cooling (compressor - condenser - liquid receiver - evaporator 1), and the other branch corresponds to grain storage for cooling or cold storage device (compressor - condenser - liquid receiver - Phase change cold storage tank-evaporator 2). The system uses a new phase change material with a phase change temperature slightly higher than the evaporation temperature of the air conditioner. It is packaged outside the evaporation coil to form an independent phase change cold storage box. The cold storage and cold release processes can be realized through the heat transfer of the coil in the box. . During the cold storage process, the coil takes away the heat of the phase change material through the lower temperature refrigerant; during the cold release process, the evaporation coil in the phase change cold storage box is connected to the evaporator in the granary. When the solenoid valve is opened, the liquid refrigerant in the cold storage box flows into the evaporator under the action of gravity, and cooperates with the evaporator fan to exchange heat with the indoor air to achieve cooling. The gaseous refrigerant flows back to the cold storage box under the action of gravity, exchanges heat with the phase change material in the box, condenses, and re-enters the granary evaporator, where it exchanges heat and evaporates, forming a cycle. By adjusting the on-off of the evaporator and each branch solenoid valve and the opening of the electronic expansion valve, the distribution between the evaporator cooling supply and cold storage is realized; by adjusting the on-off of the refrigerant circuit solenoid valve and the speed of the supporting fan, and according to the The degree of superheat is used to control the opening of the electronic expansion valve and the amount of cooling released under different working conditions.

The above are only preferred embodiments of the present utility model, and do not impose any formal restrictions on the present utility model. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present utility model still belong to the present invention. The scope of protection of utility model technical solutions.

Claims (3)

1. A rural household cold storage air conditioning system based on low-temperature grain storage, characterized in that: the rural household solar cold storage air-conditioning system based on low-temperature grain storage includes a double suction port compressor (1), a condenser (2), a storage Liquid container (3), first evaporator (4), phase change cold storage tank (5), second evaporator (6), first electronic expansion valve (7), second electronic expansion valve (8), first Solenoid valve (9), second solenoid valve (10), third solenoid valve (11), fourth solenoid valve (12), fifth solenoid valve (13), sixth solenoid valve (14), seventh solenoid valve (15), the first fan (16), the second fan (17) and the third fan (18); the double suction port compressor (1), condenser (2), first solenoid valve (9) , liquid reservoir (3), first electronic expansion valve (7), first evaporator (4), and first fan (16) form a daily cooling branch; the double suction port compressor (1), Condenser (2), first solenoid valve (9), liquid reservoir (3), second electronic expansion valve (8), phase change cold storage tank (5), third solenoid valve (11), second evaporator (6), the second fan (17), the fourth solenoid valve (12), and the sixth solenoid valve (14) form a grain storage and cooling branch circuit. 2. The rural household cold storage air conditioning system based on low-temperature grain storage according to claim 1, characterized in that: the double suction port compressor (1) and the condenser (2) are connected by pipelines for The refrigerant is compressed to produce high-temperature and high-pressure gas; the condenser (2) and the liquid reservoir (3) are connected by a pipeline for cooling the gas generated by the compression of the compressor; the liquid reservoir (3) 3) is connected to the first evaporator (4) and the second evaporator (6) through pipelines respectively, and is used to store high-pressure liquid from the condenser; the liquid reservoir (3) is connected to the third evaporator (6). An electronic expansion valve (7) and a second electronic expansion valve (8) are respectively connected by pipelines for regulating flow and controlling superheat; the first electronic expansion valve (7) is connected to the first evaporator through pipelines (4) is connected, and the second electronic expansion valve (8) is connected to the second evaporator (6) through a pipeline, which is used to evaporate the low-temperature refrigerant coming out of the electronic expansion valve under low pressure; The phase change cold storage box (5) and the second evaporator (6) are connected through a pipeline, which is used to release the refrigerant in the phase change cold storage box; the first evaporator (4) and the first fan ( 16), the second evaporator (6) and the second fan (17) are mechanically connected for cooling or heating; each solenoid valve is set on the connecting pipe for controlling the flow of fluid . 3. The rural household cold storage air conditioning system based on low-temperature grain storage according to claim 1, characterized in that: the phase change cold storage box (5) is composed of an evaporation coil and a phase change material, and the phase change material The phase change temperature is higher than the evaporation temperature of the air conditioner. The phase change material is packaged outside the evaporation coil to form an independent phase change cold storage box. The cold storage and cold release processes can be realized through the heat transfer of the evaporation coil in the box.