CN206055821U - A kind of efficient shallow ground energy-air source heat pump system - Google Patents

Abstract

A high-efficiency shallow ground energy-air source heat pump system includes two parts: a machine room unit and a machine room cold and heat source unit. The cold and heat source unit of the computer room refers to the system structure involved in the process of using the shallow ground energy system. The air gets heat from the soil in winter and cools from the soil in summer; The hot air is used as the cold and heat source of the air source heat pump placed in the closed machine room to provide cooling or heat to the regulated object. The utility model combines the outdoor buried heat exchanger of the soil source heat pump with the air source heat pump, and uses the preheated (or precooled) circulating air as the heat (cold) source of the air source heat pump, which improves (or reduces) the traditional The evaporation temperature (or condensation temperature) of the heat pump air conditioner improves the performance coefficient COP of the heat pump, and the comprehensive energy utilization efficiency of the system is greatly improved compared with the traditional air source heat pump.

Description

A high-efficiency shallow ground energy-air source heat pump system

technical field

The utility model belongs to the technical field of air source heat pump air conditioners and ground source heat pumps (including groundwater, surface water and soil heat energy), in particular to an air source heat pump system for obtaining shallow ground energy with low investment and high energy efficiency.

Background technique

At present, the development and utilization of new energy and renewable energy has become an important development strategy for many countries to solve energy and environmental problems. Ecological buildings that utilize natural energy such as solar energy, geothermal energy, and energy in the air have emerged as the times require.

As a low-temperature heat source, air is inexhaustible and inexhaustible. The use of air source heat pump can save the boiler room and cooling water system, the heat supply is pollution-free, and the energy utilization coefficient is high. However, its operating performance is greatly affected by the state parameters of the outdoor air. For example, when the outdoor temperature is high in summer (or low in winter), the COP value and cooling (heat) capacity of the air source heat pump decrease, causing the indoor temperature to be unstable. And when the outdoor temperature is too low in winter, the evaporation temperature of the air source heat pump system is too low, the COP drops sharply, the energy consumption of the system increases, and even cannot start normally. At the same time, due to the small heat capacity of the air, in order to obtain sufficient cooling and heat, a large amount of air is required, and the capacity of the fan is large, resulting in high initial investment and low energy utilization.

Ground source heat pump is a high-efficiency and energy-saving air-conditioning system that uses the heat pump principle to use the solar energy and geothermal energy absorbed in the shallow water sources on the earth's surface (such as groundwater, rivers and lakes) and soil sources, and can provide both heating and cooling. Geothermal resources can be divided into low, medium and high temperatures. The geothermal community classifies those below 90°C as low-temperature geothermal resources. Shallow low-temperature geothermal resources mainly come from the thermal radiation of the sun. Due to the energy storage effect of the soil, the heat supply in the shallow soil Stable and reliable, becoming an emerging force in renewable energy. The temperature of shallow geothermal resources on the surface is relatively stable throughout the year. It is higher than the ambient temperature in winter and lower than the ambient air temperature in summer. It is an ideal cold and heat source for central air conditioning. According to the current actual project of soil source heat pump, the buried tube heat exchanger is laid in the soil layer within 200m underground, which has relatively stable low-grade surface heat energy. For the warming zone at a depth of more than 20m, the temperature increases with the depth, and the more available land energy. However, the greater the depth, the more the drilling cost, the more complicated the construction, and the increased initial investment. The existence of shallow ground energy is based on the temperature difference between the stratum and the environment. When the stratum is too shallow, although the stratum temperature is higher than the local ambient temperature, the soil temperature under the local permafrost is only slightly higher than 0°C. The thermal energy taste is very low and cannot meet the building needs.

In order to reduce system energy consumption and achieve better energy saving, a new type of high-efficiency heat pump system combining shallow ground energy and air source heat pump is provided, which overcomes the defects of the two heat sources in use and greatly improves heat exchange efficiency.

Contents of the invention

The purpose of the utility model is to improve the outdoor heat exchange system of the traditional air source heat pump, and provide a high-efficiency shallow ground energy-air source heat pump. The heat pump device of the utility model utilizes the shallow ground within a depth of 5m to exchange heat between the circulating air and the soil, increases the evaporation temperature in winter, and reduces the condensation temperature in summer, effectively solving the attenuation of the heating capacity of ordinary air source heat pumps in winter and cooling in summer. The problem of reducing the amount of energy is greatly improved, and the coefficient of performance COP of the heat pump is greatly improved to achieve energy saving and high efficiency. At the same time, the problem that the air source heat pump cannot be started when the ambient temperature is too low (below -20°C) is solved, and the purpose of reliable operation is achieved.

The purpose of this utility model can be achieved through the following technical measures:

The shallow ground energy-air source heat pump system of the utility model includes two parts: a machine room unit and a machine room cold and heat source unit;

The cold and heat source unit of the computer room refers to the system structure involved in the process of using shallow ground energy system, circulating air to obtain heat from the soil in winter, and to obtain cold from the soil in summer. The computer room unit refers to the system structure that uses the circulating air preheated or precooled by the buried pipe system as the cold and heat source of the air source heat pump placed in the computer room to provide cooling or heat to the regulated object. in:

The cold and heat source unit of the machine room includes the vertical buried pipe of the air inlet section, the buried pipe of soil-air heat exchange, the condenser and the vertical buried pipe of the air outlet section. The soil-air heat exchange buried pipe should be set with a certain slope according to the actual situation. It is recommended to have an inclination angle of 1 to 2 degrees to condense water, and set water condensers at a certain distance to regularly remove condensed water.

The machine room unit consists of two parts: the machine room and the closed heat exchange room. It is characterized in that: the machine room includes a compressor, a four-way reversing valve, an expansion valve, an indoor heat exchanger (a condenser in winter and an evaporator in summer) and a circulating water pump, which are sequentially connected through pipelines. The heat exchange medium of the indoor heat exchanger is water; the circulating water pump is arranged on the side of the water delivery pipe of the circulating water pipeline (hot water is supplied in winter, and frozen water is supplied in summer), and the heat exchanged by the indoor heat exchanger The circulating water is sent to the air-conditioning end fan coil system in the building. The closed heat exchange chamber includes a blower, an outdoor heat exchanger part (air heat exchanger) of the air source heat pump, an air inlet shaft connected with the vertical buried pipe of the air inlet section and a vertical buried pipe connected with the air outlet section. Air outlet shaft; the air inlet shaft and the air outlet shaft are distributed on the left and right sides of the air heat exchanger and are separated by a certain distance.

The entrance of the horizontal section of the air inlet shaft in the utility model should be 1.5-2m away from the ground to reduce the inhalation of dust and pollutants, and prevent the dust and pollutants from accumulating on the inner wall of the buried pipe to affect the heat exchange effect between air and soil; To ensure the cleanliness of the air to prolong the service life of the soil-air heat exchange buried pipe, the incoming air should be filtered before entering the soil-air heat exchange buried pipe to absorb soil energy and complete the heating or cooling process of the air.

The blower in the utility model is arranged in the closed heat exchange chamber, at the entrance of the horizontal section of the air inlet shaft, blows air into the soil-air heat exchange buried pipe in the formation, and the return air returns directly to the closed machine room.

In the closed heat exchange chamber of the utility model, a certain thickness of insulation layer is laid on the outer wall to ensure an adiabatic and closed environment and prevent heat loss and air infiltration. In summer, the temperature in the heat exchange room can reach 10-15°C. The air at this temperature is used as the cold source of the air source heat pump, which reduces the condensation temperature of the traditional heat pump air conditioner by 10-15°C, thus greatly improving the cooling performance of the heat pump. Coefficient, reduce the power consumption of the air conditioner, and achieve efficient operation; in winter, the temperature in the machine room can reach 0 ℃, which is much higher than the ambient temperature, which can greatly increase the heating coefficient of the heat pump and achieve the purpose of energy saving.

The buried pipe of the soil-air heat exchange pipe in the utility model adopts the same horizontal pipe buried pipe, and the buried pipe depth is at least 1m, and it is advisable to be about 2 times the depth of the local frozen soil; keep a certain distance between the pipes. The distance b is recommended to be greater than b>10m. This distance is very good for the stable heat transfer between the air and the soil in the buried pipe, and the mutual influence is negligible.

The circulating air in the utility model is to send the air in the closed heat exchange room to the soil-air heat exchange buried pipe for heating or cooling after heat exchange by the air heat exchanger.

Compared with the prior art, the utility model has the following advantages: (1) It can simultaneously obtain heat and cooling from two huge renewable energy resources, ground energy and air, and significantly improve the COP and stability of the heat pump unit At the same time, the application range of air source heat pumps is wider, especially in the case of outdoor ambient temperature (below -20 ℃); (2) to overcome the high cost of ground source heat pumps and the danger of polluting formations and groundwater Question (3) Adopting a circulating air system, the air temperature of the return air in the closed heat exchange room is lower than the outdoor temperature in summer and higher than the outdoor temperature in winter, so the air temperature at the inlet of the buried pipe of the circulating air system is higher than that of the direct current system. The air temperature is lower (or higher), and the circulating air system is more efficient than the direct flow.

Description of drawings

Fig. 1 is the structure schematic diagram of the utility model.

Fig. 2 is the structural schematic diagram of the soil-air heat exchange buried pipe of the present utility model

Fig. 3 is a schematic diagram of the partial structure of the air supply shaft of the utility model

Fig. 4 is a schematic diagram of the partial structure of the air outlet shaft of the utility model

In Figure 1: 2—soil-air heat exchange buried pipe, 4—condenser, 5—enclosed heat exchange room, 6—machine room, 7—blower, 9—air heat exchanger, 12—compressor, 13—indoor Heat exchanger, 14-1—cooling expansion valve, 14-2—heating expansion valve, 15—four-way valve, 16—circulating water pump, 17—hot water supply in winter (frozen water in summer), 18—return water in winter (summer Cooling water).

In Fig. 2: 1—vertical buried pipe in the air inlet section, 2—buried pipe for soil-air heat exchange, 3—vertical buried pipe in the air outlet section.

Among Fig. 3: 1—the vertical buried pipe of the air inlet section, 7—the blower, 8—the air inlet shaft, 11—the filter.

Among Fig. 4: 3—the vertical buried pipe of the air outlet section, 10—the air outlet shaft.

detailed description

The utility model will be further described below in conjunction with embodiment and accompanying drawing:

As shown in Figure 1, the high-efficiency shallow ground energy-air source heat pump system of the present invention includes two parts: a machine room unit and a machine room cold and heat source unit.

The cold and heat source unit of the machine room includes the vertical buried pipe 1 of the air inlet section, the soil-air heat exchange buried pipe 2, the vertical buried pipe 3 of the air outlet section, and the condenser 4. These four parts are connected in sequence to form a system for completing the air preheating or precooling process.

The machine room unit includes two parts: a closed heat exchange room 5 and a machine room 6 .

The closed heat exchange chamber 5 includes a blower 7, an air inlet shaft 8, an air heat exchanger 9, an air outlet shaft 10, and a filter 11; the machine room 6 includes a compressor 12, an indoor heat exchanger 13, Expansion valve 14, four-way valve 15, circulating water pump 16. The centerline of the horizontal section of the air supply shaft 8 is about 1-2m above the ground, and a filter 11 is arranged at the entrance of the horizontal section. The blower 7 is connected to the horizontal section of the air supply shaft 8, followed by the vertical buried pipe 1 of the air inlet section, the buried pipe 2 of the soil-air heat exchange, the vertical buried pipe 3 of the air outlet section, and the vertical buried pipe 3 of the air outlet section. To the air outlet shaft 10, finally get back to the closed heat exchange chamber 5. The air supply shaft 8 and the air outlet shaft 10 are located on the left and right sides of the air heat exchanger 9 and have a certain distance.

In the utility model, a filter is set at the entrance of the horizontal section of the air supply shaft to prevent insects, dust and pollutants from entering the soil-air heat exchange buried pipe, and to ensure the cleanliness of the pipe, so as not to affect the heat exchange effect and the service life of the pipe.

The idea that the soil-air heat exchange buried pipe proposed in the utility model utilizes the shallow ground energy within 5m. For colder or hotter areas, although the air cannot reach the temperature required for indoor heating and cooling after flowing through the buried pipe due to the limitation of the formation temperature, it also has a great effect as the first stage of preheating or precooling. energy saving effect. And the most important thing is that compared with the use of ground energy with a depth of more than 20m, it saves drilling investment and buried pipe material investment, and reduces construction difficulty and environmental pollution problems.

The buried pipe of soil-air heat exchange adopts the same horizontal program. Horizontal buried pipes are arranged at an inclination angle of 1 to 2 degrees along the airflow direction to condense water, and condensers 4 are arranged at a certain distance to regularly remove condensed water.

Work process of the present utility model is as follows:

Heating operation: the air blower 7 blows air to the soil-air heat exchange buried pipe 2 in the formation, and the blown air passes through the soil-air heat exchange buried pipe 2 to obtain a certain amount of heat through indirect heat exchange with the soil, and then passes through the air outlet The section vertical buried pipe 3 is blown out from the air outlet shaft 10, which improves the heat source temperature of the air source heat pump, that is, increases the evaporation temperature of the air heat exchanger 9 (doing the evaporator in winter). The preheated air is blown out from the air outlet shaft 10 and returns to the closed heat exchange chamber 5 to exchange heat with the refrigerant in the air heat exchanger 9. After the refrigerant evaporates and absorbs heat, it flows through the compressor 12 and is compressed into a high-temperature and high-pressure refrigerant The steam enters the indoor heat exchanger through the four-way valve 15 to release heat to circulate water for the heat exchange medium, and the condensed low-temperature and high-pressure refrigerant liquid returns to the outdoor air heat exchanger through the heating expansion valve 14-2. The air after heat exchange by the air heat exchanger 9 is again blown into the soil-air heat exchange buried pipe 2 by the blower 7 for air preheating, and then blows out from the air outlet shaft to exchange heat with the air heat exchanger to continue the cycle.

Cooling operation: the air blower 7 blows air to the soil-air heat exchange buried pipe 2 in the formation, and the air blown in passes through the soil-air heat exchange buried pipe 2 to exchange heat indirectly with the soil to obtain a certain cooling capacity, and then passes through the air outlet The section vertical buried pipe 3 is blown out from the air outlet shaft 10, which reduces the temperature of the cold source of the air source heat pump, that is, reduces the condensation temperature of the air heat exchanger 9 (doing the condenser in summer). The pre-cooled air is blown out from the air outlet shaft 10 and returned to the closed heat exchange chamber 5 to exchange heat with the refrigerant in the air heat exchanger 9, and the low-temperature and high-pressure refrigerant liquid after condensing and releasing heat flows through the refrigeration expansion valve 14-1 Evaporate through the indoor heat exchanger, exchange heat with the return water of the fan coil unit, reduce the temperature of the cooling water, enter the compressor 12 through the four-way valve 15, compress it into high-temperature and high-pressure refrigerant vapor, and return to the outdoor air heat exchanger 9. The air after heat exchange by the air heat exchanger 9 is again blown into the soil-air heat exchange buried pipe 2 by the air blower 7 for air precooling, and then blown out from the air outlet shaft to exchange heat with the air heat exchanger to continue the next cycle.

Claims (8)

1. A high-efficiency shallow ground energy-air source heat pump system is characterized in that: it includes two parts: a machine room unit and a machine room cold and heat source unit; The system structure involved in the process of taking heat from the ground and taking cold from the soil in summer. The machine room unit refers to the circulating air that has been preheated or pre-cooled by the buried pipe system as the cold and heat source of the air source heat pump placed in the machine room. The system structure in which the regulated object provides cooling or heat. The computer room unit and the computer room cold and heat source unit are connected to form a circulating and efficient shallow ground energy-air source heat pump system. 2. The high-efficiency shallow ground energy-air source heat pump system according to claim 1, characterized in that: the machine room unit includes a closed heat exchange chamber (5), a compressor (12), a four-way valve (15), an indoor heat exchanger Heater (13), expansion valve (14), circulating water pump (16), described closed heat exchange chamber contains air supply shaft (8), blower (7), outdoor air heat exchanger (9) and air outlet shaft (10), the blower (7) is connected with the vertical buried pipe (1) of the air inlet section of the buried pipe heat exchange system through the air supply shaft (8); The direct buried pipe (1), the soil-air heat exchange buried pipe (2), the vertical buried pipe of the air outlet section (3) and the water condenser (4). 3. The high-efficiency shallow ground energy-air source heat pump system according to claim 1, characterized in that: the high-efficiency shallow ground energy-air source heat pump system is a circulating air system, which is about to seal the air in the heat exchange chamber (5) After passing through the air heat exchanger (9) for heat exchange, it is sent to the ground pipe heat exchange system for heating or cooling. 4. The high-efficiency shallow ground energy-air source heat pump system according to claim 2, characterized in that: the closed heat exchange chamber (5) must be kept in a sealed state to prevent air leakage; and the surface is provided with a layer of insulation layer to ensure Good insulation condition. 5. The high-efficiency shallow ground energy-air source heat pump system according to claim 2, characterized in that: the blower (7) is arranged at the entrance of the buried heat exchange system, and the air in the closed heat exchange chamber (5) is introduced into the The buried pipe heat exchange system in the formation, the return air returns to the closed heat exchange chamber (5). 6. The high-efficiency shallow ground energy-air source heat pump system according to claim 2, characterized in that: the air inlet shaft (8) and the air outlet shaft (10) are distributed on the left and right sides of the air heat exchanger (9) And apart from a certain distance; Wherein the horizontal entrance of the air inlet shaft (8) needs to be provided with a filter (11) to prevent dust and pollutants from entering the buried pipe system to cause pipe pollution and affect the heat exchange effect. 7. The high-efficiency shallow ground energy-air source heat pump system according to claim 2, characterized in that: the soil-air heat exchange buried pipe (2) adopts the same program horizontal buried pipe, and the buried depth of the heat transfer pipe is at least 1m or more , and it is advisable to be about 2 times the depth of the local permafrost layer; a certain distance b should be kept between pipelines, and it is recommended that b>10m. 8. The high-efficiency shallow ground energy-air source heat pump system according to claim 2, characterized in that: the buried soil-air heat exchange buried pipe (2) should be set with a slope of 1 to 2 degrees, at the lowest point of the slope Set the water condenser (4) to regularly remove air condensed water.