CN105716329B - Direct expanding solar heating pump system - Google Patents

Abstract

The invention belongs to the technical field of energy heating and air conditioning, and specifically relates to a direct expansion solar heat pump system that can collect solar energy and use phase change materials to store energy, and then use it for heating, domestic hot water and air conditioning refrigeration. Heater/regenerator/evaporator, two three-way valves, gas-liquid separator, four-way reversing valve, compressor, condensing heat exchanger, four one-way valves, electronic expansion valve, liquid receiver, dry filter Composed of heat exchanger and auxiliary evaporator, the invention integrates heat collection, heating and heat storage, reduces intermediate heat exchange, improves heat utilization rate, reduces equipment footprint, and reduces cost. It can be used for heating and domestic water. In summer, it can realize the cooling function of the room. Secondly, the heat storage of the phase change material can prevent the compressor from being overpressured and damage the compressor. The invention can use solar energy when the intensity of solar energy is weak and at night The heat storage and release of the phase change material in the heat collector/heat storage 1 realizes the continuous use of its energy.

Description

Direct Expansion Solar Heat Pump System

technical field

The invention belongs to the technical field of energy heating and air conditioning, and specifically relates to a direct expansion solar heat pump system capable of collecting solar energy and using phase change materials for energy storage, and then used for heating, domestic hot water and air conditioning refrigeration.

Background technique

Energy is the foundation of people's survival in life and is an indispensable and important part of the country. Due to the extensive exploitation of mineral resources, the storage of energy has been greatly reduced. Nowadays, the utilization of energy is in short supply, and people pay more and more attention to the development and utilization of energy. my country is a big energy utilization country, and the development and application of renewable energy, clean energy and alternative energy are urgently needed. As a clean and green energy, solar energy is favored by people for its environmental protection, sustainability, richness and other advantages.

The direct expansion solar heat pump system organically combines the utilization of solar energy with heat pump technology, improves the utilization rate of solar energy, and is environmentally friendly and energy-saving. However, the direct expansion solar heat pump has poor stability and is easily affected by factors such as seasons, climates, and day and night environments. The patent "a direct expansion solar heat pump air conditioning system" (CN103499163) introduces a solar heat pump system with phase change energy storage, which combines solar energy with phase change heat storage organically to improve the stability of direct expansion solar energy problem, but its system structure is relatively complex. The patent "direct expansion solar heat pump air conditioner and hot water system" (CN1515850A) combines solar heat pump and ice storage air conditioner, which greatly improves the collector efficiency and heat pump performance, but it does not consider the impact of environmental changes on it.

Contents of the invention

The purpose of the present invention is to provide a new direct expansion solar heat pump system to improve the stability of the existing direct expansion solar heat pump system, reduce the influence of environmental factors on it, and simplify the structure of the system at the same time.

The technical scheme adopted in the present invention:

A direct expansion solar heat pump system, consisting of solar heat collector/heat storage/evaporator, two three-way valves, gas-liquid separator, four-way reversing valve, compressor, condensing heat exchanger, four one-way valves , electronic expansion valve, liquid reservoir, dry filter, hot water storage tank and auxiliary evaporator;

Wherein, the solar heat collection/heat storage/evaporator includes a trough shell and a liquid pipeline crossing the trough shell, and tempered glass is provided at the notch of the trough shell so that the inner cavity of the trough shell is formed Confined space; heat-absorbing copper tubes and heat-absorbing flat plates are arranged inside the trough-shaped shell, the heat-absorbing copper tube is U-shaped, and its two nozzles pass through the side wall of the trough-shaped shell to the trough-shaped shell Externally, the heat-absorbing flat plate is connected to the upper tube wall of the heat-absorbing copper pipe, and the inside of the grooved shell is also filled with phase-change materials, and the heat-absorbing flat plate is horizontally covered on the upper surface of the phase-change material. The liquid conduits are in the phase change material;

The four one-way valves form a one-way valve group, and the one-way valve group has four interfaces a, b, c, and d, and the interface b of the one-way valve group passes through the liquid reservoir and the dry filter in sequence Connect with the interface d of the electronic expansion valve and the one-way valve group;

The interface a of the four-way reversing valve is connected to the inlet of the compressor through the gas-liquid separator, the outlet of the compressor is connected to the interface b of the four-way reversing valve, and the interface c of the four-way reversing valve is connected to the condensing heat exchanger The b port of the condensing heat exchanger is connected to the port a of the one-way valve group, and the port c of the one-way valve group is respectively connected to a port of the auxiliary evaporator and the upper pipe of the heat-absorbing copper pipe through the three-way valve a. The other interface of the auxiliary evaporator and the lower pipe nozzle of the heat-absorbing copper pipe are connected to the interface d of the four-way reversing valve through the three-way valve b; the solar heat collection/heat storage/evaporator The water outlet of the liquid pipeline and the d port of the condensing heat exchanger are connected to the water inlet of the hot water storage tank, the c port of the condensing heat exchanger is the water inlet, and the hot water storage tank is provided with a The water outlet connected to the pipeline, and the port d of the condensing heat exchanger is also connected to the indoor air conditioner.

Fins are also arranged inside the trough-shaped housing, and the fins are located in the phase-change material and are connected to the heat-absorbing copper pipe and the liquid pipe at the same time.

The fins are simultaneously connected to the upper tube and the lower tube of the heat-absorbing copper tube, and the liquid pipeline is located between the upper tube and the lower tube of the heat-absorbing copper tube and passes through the fins.

The heat-absorbing copper tube is fixedly arranged in the trough-shaped housing in the form that the upper tube and the lower tube are horizontal, and the upper tube is located directly above the lower tube.

There are at least two heat-absorbing copper tubes inside the trough-shaped shell, and a liquid inlet header and a liquid outlet header are arranged outside the trough-shaped shell. The upper tube nozzle and the lower tube of the heat-absorbing copper tube The nozzles are respectively connected to the liquid inlet header and the liquid outlet header, the nozzles of the liquid inlet header are connected to the three-way valve a, and the liquid outlet header is connected to the three-way valve b.

An insulating layer is also provided on the inner wall of the grooved housing.

A cut-off valve is arranged between the water outlet of the liquid pipeline of the solar heat collection/heat storage/evaporator and the hot water storage tank, the d outlet of the condensing heat exchanger and the hot water storage tank, and the hot water storage tank The water outlet is also provided with a stop valve.

The condensing heat exchanger adopts a shell-and-tube condensing heat exchanger.

The four one-way valves have two flow directions. One: The refrigerant flows from port a to port b, through the liquid receiver, dry filter, electronic expansion valve to port d, and then from port d to port c. Second: from port c to port b, through the liquid reservoir, dry filter, electronic expansion valve to port d, and then from port d to port a.

Beneficial effects of the present invention:

(1) The present invention can use the heat storage and release of the phase change material in the solar heat collector/heat storage device 1 to realize the continuous use of its energy when the solar intensity is weak and at night, effectively improving the efficiency of the existing direct expansion solar heat pump system. Stability, reducing the influence of environmental factors on it;

(2) In the present invention, the heat-absorbing flat plate adopts aluminum heat-absorbing flat plate, and the heat-absorbing layer is coated on it, which significantly improves the absorption and utilization rate of sunlight; at the same time, heat transfer fins are added under the heat-absorbing copper tube , to further enhance the heat transfer effect;

(3) The present invention adopts the thermal storage of phase change material to prevent the inlet pressure of the compressor from being too high, damage the compressor, and reduce the probability of failure of the compressor.

(4) The present invention can be used for heating and domestic water, and can realize the cooling function of the room in summer.

(5) The present invention integrates heat, heating and heat storage into one body, reduces intermediate heat exchange, improves heat utilization rate, reduces equipment footprint, and reduces cost.

(6) In the present invention, the condensing heat exchanger and the solar heat collector/heat storage/evaporator are combined in the hot water storage tank to realize centralized collection of hot water and efficient utilization of solar energy.

Description of drawings

Fig. 1 is a structural diagram of the direct expansion solar heat pump system of the present invention.

Figure 2 is the general assembly drawing of the solar heat collector/heat storage/evaporator.

Fig. 3 is a front sectional view of a solar heat collection/heat storage/evaporator.

Fig. 4 is a side sectional view of a solar heat collection/heat storage/evaporator.

Figure 5 is a structural diagram of the inner tube of the solar heat collection/heat storage/evaporator.

Detailed ways

As shown in Figures 1, 2, 3, 4, and 5, a direct expansion solar heat pump system consists of a solar collector/storage/evaporator 1, two three-way valves 2, a gas-liquid separator 3, and a four-way Reversing valve 4, compressor 5, condensing heat exchanger 6, four one-way valves 7, electronic expansion valve 8, liquid receiver 9, dry filter 10, hot water storage tank 21 and auxiliary evaporator 11; solar energy Heat collection/storage/evaporator 1 includes a trough shell 13 and a liquid pipe 22 that traverses the trough shell. Toughened glass 12 is installed at the notch of the trough shell 13 so that the inner cavity of the trough shell forms a closed space A heat-absorbing copper tube 17 and a heat-absorbing flat plate 18 are installed inside the grooved shell, and the heat-absorbing copper pipe is U-shaped, and its two nozzles all pass through the grooved shell side wall to the outside of the grooved shell, absorbing heat The flat plate is made of aluminum, on which a layer of absorbing coating can also be coated, and connected to the upper tube wall of the heat-absorbing copper pipe, and the inside of the trough-shaped shell is also filled with phase-change materials 15, and the heat-absorbing flat plate is horizontally Covering the upper surface of the phase change material, the liquid pipeline is located in the phase change material; four one-way valves form a one-way valve group, and the one-way valve group has four interfaces a, b, c, and d. The interface b of the one-way valve group is connected to the interface d of the one-way valve group through the liquid reservoir 9, the dry filter 10 and the electronic expansion valve 8 in sequence; the interface a of the four-way reversing valve is connected to the compressor through the gas-liquid separator 3 5 inlet is connected, the outlet of compressor 5 is connected to the interface b of the four-way reversing valve 4, the interface c of the four-way reversing valve is connected to the a port of the condensing heat exchanger 6, and the b port of the condensing heat exchanger 6 is connected to the single Connect to the interface a of the valve group, the interface c of the one-way valve group is respectively connected to one interface of the auxiliary evaporator 11 and the upper pipe nozzle of the heat-absorbing copper pipe 17 through the three-way valve a, and the other interface of the auxiliary evaporator 11 and the lower pipe nozzle of the heat-absorbing copper pipe are connected to the interface d of the four-way reversing valve through the three-way valve b; the water outlet of the liquid pipeline of the solar heat collection/heat storage/evaporator 1 exchanges heat with condensation Port d of the device is connected to the water inlet of the hot water storage tank, port c of the condensing heat exchanger is the water inlet, and the hot water storage tank 21 is provided with a water outlet connected to the domestic water pipe. The port d of the condensing heat exchanger is also connected with the indoor air conditioner.

Further, fins 16 are also installed inside the grooved housing, and the fins 16 are located in the phase change material and are connected to the heat-absorbing copper pipe and the liquid pipe at the same time; preferably, the fins are connected to the upper pipe and the heat-absorbing copper pipe at the same time Downpipe, the liquid conduit is located between the upper and lower tubes of the heat-absorbing copper tube and passes through the fins.

Further, the heat-absorbing copper pipe is fixedly arranged in the groove-shaped housing in a form that the upper pipe and the lower pipe are horizontal, and the upper pipe is located directly above the lower pipe.

Further, at least two heat-absorbing copper pipes are installed in the trough-shaped shell, and a liquid inlet header 20 and a liquid outlet header 19 are arranged outside the trough-shaped shell. They are respectively connected to the liquid inlet header 20 and the liquid outlet header 19, the mouth of the liquid inlet header is connected to the three-way valve a, and the liquid outlet header is connected to the three-way valve b.

Further, an insulating layer 14 is also provided on the inner wall of the grooved housing.

Further, shut-off valves are provided between the water outlet of the liquid pipeline of the solar heat collector/heat storage/evaporator and the hot water storage tank, the d outlet of the condensing heat exchanger and the hot water storage tank, and the hot water storage tank The water outlet is also provided with a stop valve 26 .

The above-mentioned condensing heat exchanger adopts a shell-and-tube condensing heat exchanger.

The above four one-way valves have two flow directions. One: The refrigerant goes from port a to port b, passes through liquid receiver 9, dry filter 10, electronic expansion valve 8 to port d, and then from port d to port c. Second: From port c to port b, through the liquid reservoir 9, dry filter 10, electronic expansion valve 8 to port d, and then from port d to port a.

In the present invention, the solar heat collection/heat storage/evaporator 1 is composed of a phase change material and a solar heat collector, which is the coupling of solar energy and the phase change material. When the heat of the solar collector is too high, the phase change material stores the excessive heat through the transformation of the state. The stored energy can be used at night or when the sun intensity weakens, which improves the stability of the direct expansion solar heat pump system. The solar heat collection/storage/evaporator 1 couples the solar heat collection and heat storage, which makes the structure of the system more compact and improves the operating efficiency of the system. And when the temperature and pressure at the outlet of the evaporator are too high, it will affect the performance of the compressor and also damage the compressor. Therefore, the solar heat collector/heat storage/evaporator 1 can well control the temperature and pressure at the inlet of the compressor by changing the phase-change materials used in different temperature zones, and protect the compressor. In the present invention, an auxiliary evaporator is connected in parallel to the solar heat collection/energy storage/evaporator 1, and the four-way reversing valve 4 and the three-way valve 2 can realize heating in winter, provide domestic hot water, and meet cooling requirements in summer.

Practical mode of the present invention:

(1) Winter operation: heating + domestic hot water mode

As shown in Figure 1, the high-temperature and high-pressure refrigerant from the compressor 5 exchanges heat with the water system through the condensing heat exchanger 6, the valve 24 is closed, and the valve 25 is opened, and this part of the hot water is used for indoor heating. After the refrigerant flows out from the condensing heat exchanger 6 , it passes through four one-way valves 7 and flows through the accumulator 9 , the filter drier 10 and the electronic expansion valve 8 . Controlled by two three-way valves 2, the refrigerant passes through the solar heat collection/heat storage/evaporator 1, and its outlet flows back to the compressor through the four-way reversing valve 4 and the gas-liquid separator, and the tap water passes through the solar heat collection/heat storage/ The evaporator 1 heats up to become domestic hot water, and at this time the valve 23 is opened to realize the functions of heating in winter and providing domestic hot water.

The solar thermal collector/thermal storage/evaporator 1 collects heat, (1) when the heat storage during the day is sufficient to provide heating and domestic hot water at night, the heat stored by the phase change material is used to provide it. (2) When the heat storage during the day is not enough to provide domestic hot water at night, the heat pump unit is used to open, the valve 25 is closed, the valve 24 is opened, and the auxiliary evaporator 11 is connected in parallel with the solar heat collection/storage/evaporator 1 The solar heat collectors 1 operate at the same time to meet people's needs, ensure the stability of the direct expansion solar energy and avoid adverse effects on the compressor 5 .

(2) During summer operation, cooling + domestic hot water mode

The high-temperature and high-pressure refrigerant flowing out from the compressor 5 passes through the four-way reversing valve 4 to the three-way valve 2, and the refrigerant is controlled by the three-way valve 2 to pass through the auxiliary evaporator 11 (used as a condensing evaporator in this working condition), and its outlet passes through Four one-way valves 7, liquid receiver 9, dryer 10 and electronic expansion valve 8 enter the condensing heat exchanger 6 (used as an evaporator in this working condition) to store cold and exchange heat with the water system to meet the cooling load of the room Requirements to achieve summer cooling. When the intensity of the sun is high during the day, the solar heat collector/heat storage/evaporator 1 can heat tap water into domestic water. At night or in rainy days, the auxiliary evaporator 11 is not activated, the refrigerant from the compressor 5 passes through the four-way reversing valve 4 to the three-way valve 2, and the three-way valve 2 controls the refrigerant to pass through the solar heat collection/storage/ The evaporator 1 exchanges heat with the phase change material, and the heat stored in the phase change material can continuously heat the domestic hot water, and at the same time meet the purposes of domestic hot water production and cooling.

(3) When operating in transitional seasons, the domestic hot water system mode

There is no need for cooling and heating in transitional seasons, and only the solar thermal collector/thermal storage/evaporator 1 is operated, and the cold water passes through the solar thermal collector/thermal storage/evaporator 1, flows through the shut-off valve 23 and is stored in the water storage tank 21 for the user Use of domestic hot water.

Claims (6)

1. A direct expansion solar heat pump system, characterized in that: the system consists of solar heat collector/heat storage/evaporator, two three-way valves, gas-liquid separator, four-way reversing valve, compressor, condensation converter Heater, four one-way valves, electronic expansion valve, liquid receiver, dry filter, hot water storage tank and auxiliary evaporator; Wherein, the solar heat collection/heat storage/evaporator includes a trough shell and a liquid pipeline crossing the trough shell, and tempered glass is provided at the notch of the trough shell so that the inner cavity of the trough shell is formed Confined space; heat-absorbing copper tubes and heat-absorbing flat plates are arranged inside the trough-shaped shell, the heat-absorbing copper tube is U-shaped, and its two nozzles pass through the side wall of the trough-shaped shell to the trough-shaped shell Externally, the heat-absorbing flat plate is connected to the upper tube wall of the heat-absorbing copper pipe, and the inside of the grooved shell is also filled with phase-change materials, and the heat-absorbing flat plate is horizontally covered on the upper surface of the phase-change material. The liquid conduits are in the phase change material; The four one-way valves form a one-way valve group, and the one-way valve group has four interfaces a, b, c, and d, and the interface b of the one-way valve group passes through the liquid reservoir and the dry filter in sequence Connect with the interface d of the electronic expansion valve and the one-way valve group; The interface a of the four-way reversing valve is connected to the inlet of the compressor through the gas-liquid separator, the outlet of the compressor is connected to the interface b of the four-way reversing valve, and the interface c of the four-way reversing valve is connected to the condensing heat exchanger The b port of the condensing heat exchanger is connected to the port a of the one-way valve group, and the port c of the one-way valve group is respectively connected to a port of the auxiliary evaporator and the upper pipe of the heat-absorbing copper pipe through the three-way valve a. The other interface of the auxiliary evaporator and the lower pipe nozzle of the heat-absorbing copper pipe are connected to the interface d of the four-way reversing valve through the three-way valve b; the solar heat collection/heat storage/evaporator The water outlet of the liquid pipeline and the d port of the condensing heat exchanger are connected to the water inlet of the hot water storage tank, the c port of the condensing heat exchanger is the water inlet, and the hot water storage tank is provided with a The water outlet connected to the pipeline, and the port d of the condensing heat exchanger is also connected to the indoor air conditioner. 2. The direct expansion solar heat pump system according to claim 1, characterized in that: fins are arranged inside the trough-shaped housing, and the fins are located in the phase change material and connected to the heat-absorbing copper pipe at the same time Connected to the liquid pipeline. 3. The direct expansion solar heat pump system according to claim 2, wherein the fins are connected to the upper tube and the lower tube of the heat-absorbing copper tube at the same time, and the liquid pipeline is located between the upper tube and the lower tube of the heat-absorbing copper tube. between the downtubes and through the fins. 4. The direct expansion solar heat pump system according to claim 1, characterized in that: the heat-absorbing copper pipe is at the level of the upper pipe and the lower pipe, and the upper pipe is located directly above the lower pipe and is fixedly arranged in the groove inside the shell. 5. The direct expansion solar heat pump system according to claim 1 or 4, characterized in that: at least two heat-absorbing copper pipes are arranged inside the trough-shaped casing, and a liquid inlet collector is arranged outside the trough-shaped casing. header and a liquid outlet header, the upper tube nozzle and the lower tube nozzle of the heat-absorbing copper tube are connected to the liquid inlet header and the liquid outlet header respectively, and the nozzles of the liquid inlet header and the three The outlet valve a is connected, and the liquid outlet header is connected with the three-way valve b. 6. The direct expansion solar heat pump system according to claim 1, characterized in that: an insulation layer is also provided on the inner wall of the trough-shaped housing.