WO2013044590A1

WO2013044590A1 - Cooling and heating unit for solar photovoltaic air conditioner

Info

Publication number: WO2013044590A1
Application number: PCT/CN2012/001307
Authority: WO
Inventors: 李士龙
Original assignee: 广州西河冷热设备工程有限公司
Priority date: 2011-09-30
Filing date: 2012-09-26
Publication date: 2013-04-04
Also published as: CN102374689A; CN102374689B

Abstract

A cooling and heating unit for solar photovoltaic air conditioner is provided, which comprises multiple sets of cooling/heating sub-systems (10), a photovoltaic direct current power system (1) which supplies electricity to cooling/heating sub-systems (10), and a controller (2). The controller (2) is connected with photovoltaic direct current power system (1) at one end and connected in parallel with the multiple sets of cooling/heating sub-systems (10) at the other side. Each set of cooling/heating sub-system (10) includes a low-power direct current compressor (3), a condenser (5), an electric expansion valve (4) and an evaporator (6)，whereinthe low-power direct current compressor (3), the condenser (5), the electric expansion valve (4) and the evaporator (6) are connected via pipelines to form a refrigerant circulating loop in which refrigerant can flow circularly. The controller (2) controls a corresponding number of cooling/heating sub-systems (10) according to the output power of the photovoltaic direct current power system (1), so that the low-power direct current compressors (3) of the corresponding number of cooling/heating sub-systems (10) are started or stopped. The cooling and heating unit for solar photovoltaic air conditioner increases the use rate of the photovoltaic direct current power system (1) and the low-power direct current compressor (3), and can make full use of solar energy.

Description

Solar photovoltaic air conditioning hot and cold unit

Technical field

The invention relates to a cold and heat system driven by a solar energy source of a photovoltaic power source for refrigeration and/or heating.

Background technique

The existing solar photovoltaic vapor compression refrigeration system uses an inverter. In operation, the DC power outputted by the solar photovoltaic panel is first boosted and inverted into alternating current, and then the alternating current is used to drive the alternating current compressor. Produce heat and cold. The price of the inverter is expensive, which increases the production cost of the system. In addition, when the sunlight intensity is insufficient, the solar photovoltaic power source and the commercial power need to be docked to mix and drive the compressor.

An ordinary solar water heater is a device that collects the energy of sunlight by using a flat type collector, a vacuum glass tube collector, and the like, thereby warming the cold water. However, this solar water heater cannot produce cold water while making hot water. In addition, although solar energy itself is an inexhaustible clean energy, when the hot water is most needed on a cloudy day, ordinary solar water heaters Hot water cannot be obtained due to insufficient sunlight.

To this end, the Chinese Patent No. "ZL 200910076400.X" discloses a solar photovoltaic one-system hybrid drive cold storage and heat storage type heat pump unit having a DC compressor and an AC compressor supplemented by each other. When the sun is sufficient, the direct current generated by the solar panel directly drives the DC compressor to obtain heat and cold, and the generated cold and heat can be directly supplied to the indoor environment requiring cooling or heat, to the indoor The air is cooled or warmed. On the other hand, the cold or heat can be stored by the phase change cold storage and heat storage medium, and then the water is cooled by the cold storage medium or the heat storage medium storing the cold or heat or Warm up to provide the user with the required cold water and/or hot water. When the sun is insufficient, the AC compressor is driven by the mains to continue the operation. The solar photovoltaic hybrid electric drive thermal storage heat pump unit is compared with the existing solar photovoltaic vapor compression refrigeration system. It does not need to use an expensive inverter to boost the DC power and convert it into AC power, and then drive the AC compressor with AC power, thereby reducing the cost of the system; compared with ordinary solar water heaters, it can be simultaneously prepared. Cold water and hot water, when the sun is insufficient, can drive the AC compressor through the mains to produce cold water and hot water.

However, this solar photovoltaic one-electric hybrid drive cold storage heat storage heat pump unit still has insufficient points. First, the photovoltaic DC subsystem of the heat pump unit is only powered by a large power DC compressor, and the DC compressor The minimum operating power is constant, and the actual output power of the solar cell photovoltaic panel is increased or decreased with the illumination intensity. And correspondingly increase or decrease, therefore, when the light intensity is weak (for example, in cloudy, rainy, morning or evening), the output of the photovoltaic DC subsystem is often less than the minimum operating power of the DC compressor. At this time, the DC compressor cannot work normally, and the utility power must be used to drive the heat pump unit. Therefore, the utilization rate of the photovoltaic DC subsystem and the DC compressor is low, the working time is small, and the solar energy cannot be fully utilized. Secondly, When the sunlight is sufficient, the rotational speed of the DC compressor increases with the increase of the output power of the photovoltaic DC subsystem, and the cooling capacity or the heat generated by the DC compressor rotating work will vary with the speed of the compressor. Increase and increase, but the rate of increase in cooling capacity or heat generation is lower than the increase rate of the operating power of the DC compressor, especially when the DC compressor enters a high-speed rotation state, even if the operating power of the DC compressor is greatly increased, However, the amount of cooling or heating produced by the work is only slightly increased. Therefore, In this operating state, the ratio of the amount of cooling produced by the DC compressor to the energy consumed by its operation (electricity) is less than 3 times, and the amount of heat generated by the DC compressor work and the energy consumed by its operation ( The power ratio of electric energy is less than 4 times. Far less than the DC compressor when it is rotating near the minimum operating power state (ie, when the DC compressor rotates at a low speed), the power ratio of the cooling capacity corresponding to the DC compressor work and the energy (electric energy) consumed by its operation, obviously the heat pump The unit has a low utilization rate of solar energy.

Disclosure of the Invention An object of the present invention is to provide a solar photovoltaic air conditioning heat and cold unit capable of making full use of solar energy and having higher cooling and heating efficiency.

A solar photovoltaic air conditioner cold and heat unit according to the present invention comprises:

a plurality of sets of cooling and heat engine subsystems, each of which includes a low power DC compressor, a condenser, an electronic expansion valve, and an evaporator, said low power DC compressor, condenser, electronic expansion valve, and evaporator Forming a circuit for circulating a refrigerant through a pipeline connection;

Photovoltaic DC power system for powering the heat and cold engine subsystem;

One end of the controller is connected to the photovoltaic DC power system, and the other end is connected in parallel with multiple sets of cooling and heat engine subsystems. The controller controls the corresponding number of cooling and heating subsystems according to the output power of the photovoltaic DC power supply system, so that the cooling and heating machine subsystem is small. The power DC compressor starts or stops.

The invention is provided with a plurality of cooling and heating machine subsystems with small power DC compressors, and connects the photovoltaic direct current power system with a plurality of sets of cooling and heat engine subsystems through a controller, and the controller can be output according to the photovoltaic direct current power system Power to control the corresponding number of hot and cold machine subsystems, to enable or disable the DC compressor of the cooling and heating subsystem, so when the light intensity is weak (eg, cloudy, rainy, morning, or evening), Although the output power of the photovoltaic DC power system is relatively small, the minimum operating power of the small power compressor is relatively small, so it is easy to meet the minimum operating power of at least one low-power DC compressor. At this time, the controller is based on the photovoltaic DC. The power output from the power system starts the corresponding number of DC compressors (for example, when the output power of the PV DC power system is greater than the minimum operating power of a small power DC compressor, the controller starts a DC compressor operation, when When the output power of the photovoltaic DC power system is greater than the sum of the minimum operating powers of the two DC compressors, the controller starts the corresponding two DC compressors, and so on, to obtain the cooling capacity or heat, which is obviously improved. The use of photovoltaic DC power systems and DC compressors to extend DC compression The daily working hours of the machine make more full use of solar energy; when the sun is sufficient, the photovoltaic DC power system distributes the output power to multiple sets of cooling and heat engine subsystems through the controller, so that each low-power DC compressor can be used. At a lower speed, in this operating state, the ratio of the amount of cooling produced by the DC compressor to the energy consumed by its operation can be more than 4 times, and the heat generated by the DC compressor is correspondingly generated. The power ratio of the consumed energy is more than 5 times. Obviously, compared with the prior art, the heat and cold unit of the present invention has higher utilization rate of solar energy and can better meet the purpose of energy saving.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of the invention.

2 and 3 are schematic views of an embodiment of the present invention.

4 and 5 are schematic views of another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1 , the solar photovoltaic air conditioner cold and heat unit of the present invention comprises a plurality of sets of cooling and heat engine subsystems 10, each of which comprises a low power DC compressor 3, a condenser 5, and an electronic unit. The expansion width 4 and the evaporator 6, the low-power DC compressor 3, the condenser 5, the electronic expansion valve 4, and the evaporator 6 are connected by a pipeline to form a circuit for circulating a refrigerant; the photovoltaic DC power system 1, for powering the cooling and heating machine subsystem 10, the photovoltaic DC power system 1 is composed of a plurality of solar battery modules connected in series and in parallel according to the requirements of the load; one end of the controller 2 is connected with the photovoltaic DC power system, and the other end is connected in parallel Multiple sets of hot and cold machine subsystem 10, controller 2 according to light The power outputted by the VDC power supply system 1 controls a corresponding number of the heat and cold engine subsystems 10 to start or stop the low-power DC compressor 3 of the heat and cold engine subsystem 10, and the number of the heat and cold engine subsystems 10 can be based on the photovoltaics. The maximum output power of the DC power system 1 and the power of each of the heat and cold engine subsystems 10 are set (as shown in Figure 1 for the two sets of the heat and cold engine subsystems 10). When the light intensity is weak (for example, in cloudy weather, rainy weather, morning or evening), the power outputted by the photovoltaic power supply system 1 is relatively small, but the minimum operating power of the low power compressor 3 is relatively small. Therefore, it is easy to meet the minimum operating power of at least one low-power DC compressor 3. At this time, the controller 2 starts the corresponding number of DC compressors 3 according to the power output from the photovoltaic DC power system (for example, when the photovoltaic DC power supply) When the output power of the system is greater than the minimum operating power of a small power DC compressor, the controller starts a DC compressor operation. When the output power of the PV DC power system is greater than the sum of the minimum operating powers of the two DC compressors, The controller starts the corresponding two DC compressors, and so on, to obtain the cooling capacity or heat, which obviously increases the utilization rate of the photovoltaic DC power system 1 and the DC compressor 3, and extends the daily work of the DC compressor. Time, more fully utilize solar energy; and when there is sufficient sunlight, the photovoltaic DC power system 1 passes The controller 2 distributes the output power to the plurality of sets of the heat and cold engine subsystems 10, so that each of the low-power DC compressors 3 can be operated at a lower speed. In this operating state, the DC compressor 3 is correspondingly produced. The ratio of the amount of cooling to the energy consumed by the operation can be more than 4 times, and the ratio of the amount of heat generated by the DC compressor 3 to the energy consumed by the operation of the DC compressor 3 is more than 5 times. Obviously, the present invention The heat and heat unit has higher utilization rate of solar energy and can better meet the purpose of energy saving.

The motor of the DC compressor 3 can adopt a DC brushless permanent magnet motor or a DC brushed permanent magnet motor, but the carbon brush of the DC brushed permanent magnet motor has a short service life and a high replacement frequency. Moreover, the replacement operation is troublesome. For this reason, the DC compressor motor can be preferentially selected as a DC brushless permanent magnet motor; in addition, in order to reduce the minimum operating power of the DC compressor 3, the pump body of the DC compressor can be a rotary compression pump.

The controller 2 can be electrically connected to an AC power source (not shown) through a rectifying device (not shown), so that when the photovoltaic power system of the photovoltaic DC power system is insufficient, or there is no light at night, the AC can be exchanged. The power supply is used as a supplementary power source, and the alternating current output from the alternating current power source (such as the commercial power) is first rectified into direct current by the rectifying device, and then sent to the controller 2 for the controller 2 to drive the cold heat engine subsystem 10.

Embodiment 1: The condenser 5 may be an air-cooled condenser or a water-cooled condenser; the evaporator 6 may be an air-cooled evaporator or a water-cooled evaporator, as shown in FIG. The case is an air-cooled condenser, and the evaporator 6 is an air-cooled evaporator. As shown in FIG. 2, the evaporator 6 is a water-cooled evaporator, and the condenser 5 is an air-cooled condenser. The cooling coil of the water-cooled evaporator is placed in the cold storage tank 20 (the cooling coils of the respective water-cooled evaporators can be separately Placed in different cold storage tanks, or all or part of the same cold storage tank, as shown in Figure 2, multiple cooling coils are placed In the case of the same cold storage tank, the liquid (such as water) in the cold storage tank 20 can be cooled. The cooling coil can be a copper tube or a stainless steel tube, and the cooled water can be directly used as cold water for daily use; The water pump 30 is taken out and is cooled by the fan coil 40 to the indoor air that needs to be cooled. The water pump 30 communicates with the water inlet and the water outlet of the cold storage tank 20 through the pipeline to form a circulation circuit for the water supply flow; It can also be pumped out by the water pump 30 and dissipated through a cold air sheet (not shown) to the indoor air that needs to be cooled. The water inlet of the water pump 30 is connected to the water outlet of the cold storage tank 20, and the water inlet of the cold air sheet is connected. And the water outlet is respectively connected with the water outlet of the water pump and the water inlet of the cold storage box, and the cold air sheet is a prior art (for example, the cold air sheet described in the patent application of the Chinese Patent Publication No. CN 1079041). The specific structure will not be described here, but when the cold air sheet cools the indoor air, the temperature difference between the cold air sheet and the indoor air will cause condensation on the outer surface of the cold air sheet. Dripping wet ground and, for this purpose, can be placed in the basin under the air-filled sheet (not shown) to cool air from the accommodating sheet dripping condensation water. A temperature sensor (not shown) may be disposed on the cold storage tank 20, and the temperature sensor is electrically connected to the controller. When the temperature of the liquid in the cold storage tank 20 detected by the temperature sensor reaches a set value, the controller 2 makes the corresponding cold The DC compressor 3 of the heat engine subsystem 10 stops working, and the solar energy can be more fully utilized in this way, and the amount of cold stored in the liquid of the cold storage tank 20 when the sunlight is sufficient can be when the light intensity is extremely weak (such as night, rainy day). When the pump is taken out by the water pump, the cooling coil is dissipated into the indoor air. Instead of the prior art, the utility model is required to drive the heat pump system to obtain the cooling capacity. Obviously, a large amount of energy can be saved. The amount of cooling that is blown out by the fan coil 40 or emitted by the cold air sheet is cooler, unlike the cold air blown out by the air-cooled evaporator, which makes it difficult for people with weak constitution to adapt. Similarly, when the condenser 5 is a water-cooled condenser, the heating coil can be placed in the heat storage tank, and the water heated by the heating coil can be directly used as domestic hot water, or can be heated by a fan coil or a radiator. Blow off or dissipate into an indoor environment that requires warming.

As shown in FIG. 3, in order to make the solar photovoltaic air conditioner cold and heat unit meet different requirements and save system manufacturing cost, the refrigerant that can flow out of the direct current compressor 3 can be disposed in the cold heat engine subsystem 10 to flow forward through the condenser 5 And the evaporator 6, or the reverse flow through the condenser 5 and the evaporator 6, and then returned to the four-way switching valve 71 of the compressor 3, the flow direction of which is switched by the switching valve on the four-way switching valve 71 Wherein, the forward flow direction of the refrigerant is: Compressor 3 - Four-way reversing valve 71 - Condenser 5 - Electronic expansion valve 4 - Evaporator 6 → Four-way reversing valve 71 - Compressor 3; Refrigerant The reverse flow direction is: compressor 3 - four-way reversing valve 71 - evaporator 6 - electronic expansion valve 4 - condenser 5 - four-way reversing valve 71 → compressor 3. After the refrigerant is reversely circulated by the four-way switching valve 71, the condenser 5 can be generated by the heat generated when the refrigerant flows in the forward direction, and the evaporator 6 is cooled by the forward flow of the refrigerant. The amount becomes heat.

Embodiment 2: As shown in FIG. 4 and FIG. 5, in order to make better use of solar energy, the electronic expansion width 4 and DC voltage A heating coil 8 is coupled between the compressors 3 through the three-way switching valve 72. The heating coil 8 may be a copper tube or a stainless steel tube. The heating coil 8 is placed in the thermal hot water tank 50. The water therein is heated, and the heated water can be directly used as domestic water. The hot water tank 50 and the electronic expansion valve 4, and the condenser 5 and the electronic expansion valve 4 are respectively disposed to control the hot water tank 50. And an electronic expansion valve 4, and a check valve 91, 92 between the condenser 5 and the electronic expansion valve 4, and a temperature sensor (not shown) may be disposed on the heat preservation hot water tank 50, the temperature The sensor is electrically connected to the controller 2, and when the temperature sensor detects that the temperature of the liquid in the hot water tank 50 reaches the set value (the set value is generally 50-60 ° C, in many cases 55 ° C) The controller 2 starts the three-way reversing width 72, so that the refrigerant is switched from the heating coil flowing into the hot water tank 50 to the condenser 5, and the hot water tank and the electronic expansion are widened by the one-way valve 91. The pipeline between 4 is cut off; similarly, the three-way reversing valve 7 can also be controlled by the controller 2 2, so that the refrigerant does not flow through the condenser 5. The condenser 5 may be a water-cooled condenser or a wind condenser. The evaporator may be a water-cooled evaporator or an air-cooled evaporator. As shown in FIG. 4, the evaporator 6 is a water-cooled evaporator. When the condenser 5 is an air-cooled condenser, the cooling coil of the water-cooled evaporator is placed in the cold storage tank 20, and the liquid (such as water) of the cold storage tank 20 can be cooled, and the cooled water can be directly used as a living thing. The cold water can also be pumped out by the water pump 30 and radiated by the fan coil 40 to the indoor air that needs to be cooled. The water pump 30 communicates with the water inlet and the water outlet of the cold storage tank through the pipeline to form a circulation for liquid flow. The circuit can also be pumped out by the water pump 30 and radiated by the cold air sheet to the indoor air that needs to be cooled. The water inlet of the water pump is connected with the water outlet of the cold storage tank, and the water inlet and the water outlet of the cold air sheet are respectively The water outlet of the water pump is connected to the water inlet of the cold storage tank, and when the cold air sheet cools the indoor air, the temperature difference between the cold air sheet and the indoor air causes condensation water to form on the outer surface of the cold air sheet. Wet ground, for this purpose, can be placed in the basin under the air-filled sheet (not shown) to cool air from the accommodating sheet dripping condensation water. As shown in FIG. 5, in the case where the evaporator 6 is an air-cooled evaporator and the condenser 5 is a water-cooled condenser, the heating coil of the water-cooled condenser is placed in the heat storage tank 60, and the liquid of the heat storage tank 60 can be If heated, the heated water can be directly used as hot water for daily use, or it can be pumped out by a water pump and radiated by a fan coil or a radiator (not shown) to the indoor air to be heated. The water pump communicates with the water inlet and the water outlet of the heat storage tank through the pipeline to form a circulation loop of the water supply flow.

Claims

Claim

1. A solar photovoltaic air conditioning heat and cold unit, characterized in that it comprises:

Photovoltaic DC power system for powering the heat and cold engine subsystem;

The controller has one end connected to the photovoltaic DC power system, and the other end is connected in parallel with a plurality of sets of cooling and heating subsystems. The controller controls the corresponding number of the heating and cooling subsystems according to the output power of the photovoltaic DC power supply system, so that the cooling and heating machine The system's low power DC compressor starts or stops.

The solar photovoltaic air conditioner cold and heat unit according to claim 1, wherein: the controller is electrically connected to an alternating current power source through a rectifying device.

3. The solar photovoltaic air conditioning heat and cold unit according to claim 1, wherein: the motor of the DC compressor is a DC brushless permanent magnet motor, and the pump body is a rotary compression pump.

The solar photovoltaic air conditioning and cooling unit according to claim 1, wherein the photovoltaic power supply system is formed by connecting a plurality of solar battery modules in series and in parallel according to load requirements.

The solar photovoltaic air conditioner cold and heat unit according to claim 1, wherein: the electronic expansion valve and the direct current compressor are coupled with a heating coil through a three-way reversing valve, and the heating coil is placed in the heat preservation. Inside the hot water tank.

The solar photovoltaic air conditioner cold and heat unit according to claim 5, wherein: the insulated hot water tank and the electronic expansion valve, and the condenser and the electronic expansion valve are respectively disposed to control the hot water tank And an electronic expansion valve, and a through-and-off check valve between the condenser and the electronic expansion valve, and a temperature sensor can be disposed on the hot water tank, and the temperature sensor is connected to the controller.

The solar photovoltaic air conditioner cold-heating unit according to any one of claims 1 to 6, wherein: the evaporator is an air-cooled evaporator or a water-cooled evaporator; when the evaporator is a water-cooled evaporator, The cooling coil of the water-cooled evaporator is placed in a cold storage tank.

The solar photovoltaic air conditioner cold and heat unit according to claim 7, wherein: the water outlet of the cold storage tank is connected with a water pump, and the water outlet of the water pump is connected with a cold air sheet or a fan coil, a cold air sheet or The water outlet of the fan coil communicates with the water inlet of the cold storage tank to form a circulation loop for the flow of cold water.

The solar photovoltaic air conditioner cold and heat unit according to any one of claims 1 to 6, wherein: The condenser is an air-cooled condenser or a water-cooled condenser; when the condenser is a water-cooled condenser, the heating coil of the water-cooled condenser is placed in the heat storage tank.

The solar photovoltaic air conditioner cold and heat unit according to claim 9, wherein: the heat storage tank is provided with a temperature sensor, and the temperature sensor is connected to the controller.