471 results about "Solar water heating system" patented technology

A fault detection system for use with a solar hot water system may include a data acquisition module which may, in turn, include a plurality of sensors. Input data may include a sensed condition. The system may also include a neural network to receive the input data which may be a multi-layer hierarchical adaptive resonance theory (ART) neural network. The neural network may perform an analysis on the input data to determine existence of a fault or a condition indicative of a potential fault. The fault and the condition indicative of the potential fault are prioritized according to the analysis performed by the neural network. A warning output relating to the fault and the condition indicative of the potential fault is generated responsive to the analysis, and is displayed on the user interface.

A tankless water heating auxiliary system for a solar water heating system, includes a solar collector; a tankless water heater auxiliary system; an insulated water storage tank storing the potable water; a heat exchange system for heating stored water; and piping for connecting the collector, the storage tank and the heat exchanger in fluid communication. A first sensor is connected to and located adjacent the storage tank for sensing the temperature of the stored water at an outlet of the tank. A method for controlling initiation of heating in a tankless water heater auxiliary system, includes monitoring operation of a tankless water heater; measuring water flow using a water flow sensor to determine if water flow rate exceeds a use determined flow rate; implementing a control time delay into the tankless water heater to purge water from the heater and sense the inlet water supply temperature; measuring the water temperature using a heat exchanger outgoing thermistor; comparing the temperature measured by the thermistor to a predetermined temperature; and initiating a combustion sequence if the temperature measured by the outgoing themistor is less than the predetermined temperature.

The invention discloses a bulk curer heat supply and ventilation system supplied by combined solar energy-air source heat pump double heat sources, which consists of a solar water heating subsystem, an air source heat pump water heating subsystem, an air-water heat exchanger, a frequency conversion circulating water pump, a heat insulating hot water pipeline, a main controller, a circulating fan, an air supply pipe, a fresh air valve and a curer wet air outlet. A condenser of the air source heat pump water heating subsystem is arranged in a heat accumulating water tank; the air source heat pump water heating subsystem is coupled with the solar water heating subsystem through the heat accumulating water tank; and the air source heat pump water heating subsystem adopts a CO2 high temperature refrigerant to prepare high temperature hot water between 85 and 90DEG C. The bulk curer heat supply and ventilation system adopts the solar water heating system and the air source heat pump water heating system, which are combined to operate, to supply heat to the curer, fully utilizes the clean solar energy and low-grade heat energy in the atmosphere, has the advantages of energy conservation, environmental protection and the like, and can realize loss minimization and value addition in the process of curing tobacco leaves.

The invention discloses a self-balancing integrated application system of a solar energy-ground source heat pump, comprising an air conditioner end system, a ground source heat pump system, a hot water supply system, a solar energy heat-collection system and an automatic control system, wherein the ground source heat pump system comprises a ground buried pipe heat exchanger (6), a compressor (1),an indoor side heat exchanger (3) and an environment side heat exchanger (5), and the automatic control system is used for controlling all the automatic equipment in the self-balancing integrated application system of the solar energy-ground source heat pump. The invention can effectively realize the functions of cold and warm air conditioning and hot water supply, mainly can switch the working modes of the ground source heat pump and a solar energy hot water system automatically by the control system, thereby solving the problem of imbalance of the ground source heat pump in winter and summerand enhancing the utilization rate of regenerative energy (solar energy and geothermal energy) in energy used for construction to the maximum.

A composite energy system of solar energy, ground source heat pump and chilled water storage comprises an air conditioner, a domestic hot water supply device, one or more device (hereinafter referred to as host) of a solar energy heat-collecting device, a heat storage water tank unit, a cold storage water tank unit and a ground source heat pump system, a ground heat exchanger, an auxiliary heating device, a circulating water pump, a first electric three-way valve, a second electric three-way valve, a first electric two-way valve and a second electric two-way valve, wherein the circulating water pump is communicated with the air conditioner, and the auxiliary heating device is communicated with the domestic hot water supply device. The invention fully utilizes renewable energy sources such as solar energy, geothermal energy and biomass energy to masterly combine the ground source heat pump air-conditioning system with the solar energy hot water system and the chilled water storage system and construct a comprehensive energy system combined by the domestic hot water system, the ground source heat pump, the chilled water storage air-conditioning system and the like; and the invention is completely combined with the entire building so as to greatest reduce the floor space and the investment and increase the energy efficiency and economic performance of the system.

Solar water heating systems that are formed as all-in-one kits that include all the components necessary for assembling the solar water heating systems at a chosen site is disclosed. Depending on the desired system, the kit may for example include a solar collector, one or more supplemental storage tanks, pumps, heat exchangers, valves, fittings, piping, timers, insulation, flashings, hose bibs, supports, brackets, fasteners, sealants and / or the like. In fact, the kit may further include all or some of the necessary tools required to assemble the solar water heating system.

The invention relates to a model-prediction-control-based optimized dispatching method of an integrated energy system of a park. The method comprises: according to a selected integrated energy systemof a park, structure and parameters of the integrated energy system of the park are inputted; operational constraints of the integrated energy system of the park are established; a minimized sum of operation costs and equipment on-off costs of the integrated energy system of the park in a prediction domain at a rolling optimization stage is set to be an objective function and a minimized sum of operation costs and power adjustment punishment costs of the integrated energy system of the park within a single interval at a dynamic adjustment stage is set to be an objective function; optimized dispatching is carried out by using a rolling-optimization-based multi-time scale optimization dispatching method; and a dispatching plan of the system within one dispatching cycle is outputted, whereinthe dispatching plan includes operation costs, a heat supply water power of a solar hot water system, a ground source heat pump, a start-stop command of an electric boiler, an operating situation, anenergy supply power, a running condition of a thermal-storage water tank, and an energy supply power. According to the invention, optimized dispatching of the integrated energy system of the park is realized; the influence caused by the load and renewable energy output prediction errors is reduced effectively; and the energy demand of the system is satisfied economically and reliably.

The invention discloses a phase change heat storage material with multiple phase change points. The material is prepared by compounding at least two phase change materials with different phase change temperatures and then adding a stabilizing agent. In the material compounding step, phase change materials are added into a reactor according to the phase change temperatures, materials with lower phase change temperatures are added into the reactor at first, the phase change materials are melted and stirred in the reactor, and after the phase change materials are fully stirred, a stabilizing agent is added. The invention further discloses a preparation technology of the phase change heat storage material. The preparation technology comprises the following steps: preparing a first phase change material, preparing a second phase change material and a stabilizing agent; adding the first phase change material into the reactor, heating the first phase change material until the first phase change material is completely melted, stirring; adding the second phase change material into the reactor, stirring; adding the stabilizing agent into the reactor, stirring; and carrying out DSC tests to obtain a phase change material with multiple phase temperature points. The phase change material can be applied to specific fields such as a heat accumulating type solar hot water system, the sunshine states in winter and summer can be adapted effectively, the energy is effectively utilized, and the heat supply efficiency of the hot water system is improved.

The invention relates to a shower, heating and air conditioning complex system device for producing hot water by using solar energy, air source and low power. The device is formed by grafting and compounding a solar water heating system, a shower system, a floor heating system and an auxiliary heating system, and is provided with a control system; the auxiliary heating system is formed by grafting and compounding an air source pump and an air conditioner; in a steam compression refrigeration system of the air conditioner, a third heat exchanger which takes water as a heat exchange medium and one of a first heat exchanger and a second heat exchanger which takes air as the heat exchange medium in the system are connected with each other in parallel by using a pair of tee joints and two pairs of electromagnetic valves; and the third heat exchanger is provided with a temperature controller, is connected with a solar hot water storage tank by using a water inlet pipe and a water outlet pipe in a sealing way, and is connected with a hot water pump and an electromagnetic valve. The device has the advantages of saving electricity by 70 percent compared with an electric heater and saving a host compared with a special air-source heat pump, can be used for heating in winter and used for conditioning air in summer, recovers waste heat discharged from an original outdoor unit for producing hot water used for shower without reducing an energy efficiency ratio, acquires two gains by using one part of power, saves energy and reduces emission.

An integrated alternative energy roofing panel incorporates an array of solar concentrator tubes interconnected with transparent web to form a joined plate supported in frame elements with an attached working fluid manifold. The working fluid in the manifold is operatively in contact with the solar concentrator tubes for transferring heat from the tubes. In one exemplary construction, each of the solar concentrator tubes terminates in a conducting metal sleeve which extends beyond the frame element into the manifold. A safety glass panel is attached to one frame element beneath the joined plate. The joined plate and safety glass panel may be sealed to the frame elements to form a chamber and the chamber may be evacuated. A plurality of light emitting diodes (LEDs) are embedded in the web for supplemental lighting. An array of photovoltaic cells mounted to a top surface of the manifold and a battery are interconnected for powering the LEDs. The manifold incorporates a compartment to house the battery as a portion of the integrated panel.

The invention relates to a heat pump marsh gas tank, in particular to an air energy, solar energy and ground source heat pump marsh gas tank, which belongs to environment engineering equipment. The heat pump marsh gas tank consists of an anaerobic digestion system, a heat insulation and thermal preservation system, a solar energy hot water system, an air energy heat pump system, a ground source heat pump system and a control system, wherein the tail end heat exchange equipment of the ground source heat pump system, solar energy hot water pipelines and the air energy heat pump system are connected with the heat insulation and thermal preservation system and the anaerobic digestion system through hot water circulation pipes, a hot water transit box arranged in the thermal preservation system is used for regulating and balancing the hot water of heat resource systems, hot water heats the anaerobic digestion tank through circulation pipes for promoting the anaerobic digestion, and the hot water circulation pipes can be arranged inside the anaerobic digestion tank and can also be arranged outside the anaerobic digestion tank. The marsh gas tank can also provide hot water and cold air at the same time of producing marsh gas, and the invention can solve the problems of high production cost, great energy consumption and the like of winter production of the marsh gas engineering, and can be popularized easily.

The invention discloses a renewable energy source, self-adaptation and energy gradient utilization integrated air-conditioning system. The renewable energy source, self-adaptation and energy gradient utilization integrated air-conditioning system comprises an evaporative cooling air-conditioning unit, a solar power generation and supply system, a solar water heating system, an evaporative cooling air-conditioning unit rainwater collection water complementing system and a carbon dioxide automatic monitoring system, wherein the solar power generation and supply system, the solar water heating system, the evaporative cooling air-conditioning unit rainwater collection water complementing system and the carbon dioxide automatic monitoring system are respectively connected with the evaporative cooling air-conditioning unit, and the evaporative cooling air-conditioning unit is communicated with an air-conditioning area through an air pipe network. By means of the air-conditioning system, solar power generation, solar water heating and rainwater collection can be integrated, and meanwhile distribution of return air is reasonably controlled through a carbon dioxide monitor so that the cooling capacity generated by the unit can be completely utilized, and the good indoor air quality can be maintained.

The invention discloses a concentration type solar hot water supply system for independent units of high-floor buildings or multi-layer buildings, which comprises a circulatory water return device and an integration control device, wherein the circulatory water return device deliveries hot water to users; the integration control device processes the received water temperature and liquid level signals, and sends a control command to a water supplementing device and the circulatory water return device; a water temperature sensor electrically connected with the integration control device is arranged on a heat collecting circulatory pipeline; a water level sensor connected with the integration control device to detect water levels is arranged on a heat collecting water tank; and a water temperature sensor of the water tank electrically connected with the integration control device is arranged on the heat collecting water tank. The invention integrates the solar hot water system and the buildings into a whole, and each residence in the unit can use the solar hot water. The invention has the advantages of low manufacture cost, simple system, less components, convenient mounting and use, convenient management and low running cost, is easy to accept by real estate developers, owners and property management companies, and is suitable for mounting in existing buildings and newly built buildings.

The invention discloses a solar-powered VM circulating heat pump system, which comprises a VM circulating heat pump system, a solar water heating system, a heat supply circuit and a cold energy supply circuit, wherein a heat source heat exchanger is arranged between a hot cylinder and a heat regenerator in the circulating heat pump system; the heat source heat exchanger and a water container in the solar water heating system form a heat exchange circulating system; and the energy transfer between the two systems is completed. When the system is used, solar can be used as driving energy to drive a VM circulating heat pump to work to cool or heat in order to meet an air conditioner cooling requirement. The solar is clean, safe and reliable, so energy shortage and environmental pollution are prevented. The system can be widely used in industrial, commercial and civil concentrated cooling and heating systems.

The invention relates to a cooling, heating and generation and hot-water supply combined system driven by a proton film fuel cell. The cooling, heating and generation and hot-water supply combined system comprises the fuel cell, a first water pump, an auxiliary heating device, a second water pump, a third water pump, a storage heat exchange device, an absorptive cold and hot water unit, a fan coiler and air-conditioner end equipment, which are communicated through pipelines. The waste heat of the fuel cell is utilized, and solar renewable energy sources are introduced, so that the problems of generation of living buildings, heating in winter, cooling in summer and daily water usage of buildings are solved. Combining waste heat of the natural gas fuel cell with the solar hot water system, high-temperature hot water is generated, the absorptive cold and hot water unit can be started for cooling and heating of an air conditioner, hot water flowing out of the absorptive cold and hot water unit can be used for daily life after treated through a heat exchanger, gradient utilization of the energy sources is realized and utilization rate of fossil fuel is increased.

The invention relates to solar water heating technology, in particular to a novel solar water heating system. The novel solar water heating system comprises a vacuum tube solar collector, and a hot water storage tank, wherein the vacuum tube solar collector comprises a bracket and a group of euphotic tubes which are fixed on the bracket and provided with vacuum interlayers; one end of each of the euphotic tubes is connected with the hot water storage tank; a flat heat pipe is arranged in a middle cavity of the euphotic tubes; one end of the flat heat pipe is inserted in the hot water storage tank or is connected with the hot water storage tank; and the flat heat pipe is provided with a through hole which is filled with working substances, and two ends of the flat heat pipe are sealed to form a heat pipe structure. In the novel solar water heating system, the flat heat pipe provided with a capillary heat pipe is arranged in the conventional vacuum glass tube, thereby greatly improving the absorption efficiency of solar energy and the heat transmission efficiency; and compared with the conventional solar water heating system, the novel solar water heating system greatly improves the absorption efficiency of the solar energy and the heat transmission efficiency, and has simple structure, low cost and application and promotion values .

The present invention includes a solar water heating system including: a water tank to hold water to be heated, an heat transfer fluid circuit including an heat exchanger associated with said water tank to heat water therein, a solar collection means in communication with said heat exchanger, an inlet connection to carry heat transfer fluid from said solar collection means to said heat exchanger where said water will be heated; and an outlet connection to carry heat transfer fluid from said heat exchanger to said solar collection means where said heat transfer fluid will be heated, said heat transfer fluid circuit including a reversibly evaporable heat transfer fluid which will absorb heat from said solar collection means and which will transfer said heat to said water in said water tank by means of said heat exchanger; and an diversion path being provided in said heat transfer circuit, whereby when a portion of heat transfer fluid changes to a gaseous state in said solar collection means, heat transfer fluid in a liquid state will be forced out of said solar collection means under pressure into said diversion path.

The invention discloses a boiling type regenerative solution dehumidification system driven by solar energy and ground source energy. The system comprises a dehumidifier, a dehumidifier heat exchanger and the like, wherein the dehumidifier is connected with the dehumidifier heat exchanger and a solution heat exchanger respectively, the dehumidifier heat exchanger is connected with a liquid recirculation pump, the liquid recirculation pump is connected with the dehumidifier, the solution heat exchanger is connected with a throttle and a solution pump respectively, the throttle and the solution pump are connected with a generator, a dehumidifying solution is arranged inside the dehumidifier, the dehumidifying solution sequentially passes the dehumidifier, the solution heat exchanger, the throttle, the generator and the solution pump, the solution heat exchanger, the dehumidifier, the dehumidifier heat exchanger, a dehumidifier solution recirculation pump 3 and a dehumidifying solution nozzle are connected sequentially to form a dehumidifying solution circulation loop, a solar hot water system and the generator are connected to form a heat source loop, a buried pipe heat exchanging system is respectively connected with a condenser and the dehumidifier heat exchanger, and a respective cold source loop is formed.

A photovoltaics teaching aid. The present device is adapted to serve as a teaching aid in order to assist individuals in learning the principles behind photovoltaics, in order to better promote science, technology, engineering, and mathematics (STEM) education. The present invention is a transportable cart including an angled, adjustable array of solar panels, a rechargeable battery, and a solar water heating system. The present invention further includes a number of different devices that are removably attached to the cart to assist individuals in making necessary measurements for calculations, including a multimeter and an angle gauge. Furthermore, a bus is provided that allows individuals to alternatively connect the panels of the solar array in series or in parallel. By changing the manner by which the panels are connected, individuals can study the different resulting effects on the other electrical components.

The present invention includes a solar water heating system including: a water tank to hold water to be heated, an heat transfer fluid circuit including an heat exchanger associated with said water tank to heat water therein, a solar collection means in communication with said heat exchanger, an inlet connection to carry heat transfer fluid from said solar collection means to said heat exchanger where said water will be heated; and an outlet connection to carry heat transfer fluid from said heat exchanger to said solar collection means where said heat transfer fluid will be heated, said heat transfer fluid circuit including a reversibly evaporable heat transfer fluid which will absorb heat from said solar collection means and which will transfer said heat to said water in said water tank by means of said heat exchanger; and an diversion path being provided in said heat transfer circuit, whereby when a portion of heat transfer fluid changes to a gaseous state in said solar collection means, heat transfer fluid in a liquid state will be forced out of said solar collection means under pressure into said diversion path.

The invention relates to solar refrigeration low temperature grain storing air conditioning system. It belongs to energy saving technical field. It includes solar heat collection device and high efficiency back-heating back-quality continuous refrigeration adsorption refrigerating machine, control system, grain storage air supply and air conditioning system. Compared with absorption refrigerating machine, it has lower driving hot source temperature and cost. And compared with intermittent, it can automatically and continuously do refrigeration, and has higher coefficient of performance. And it can be widely used in grain storing department.

The invention discloses a solar energy and phase-change energy storage material integrated energy self-maintaining building. The solar energy and phase-change energy storage material integrated energy self-maintaining building comprises a phase-change house and a solar energy system arranged on the roof. Phase-change sleeves are buried in the concrete floor of the phase-change house; a phase-change material is arranged in each phase-change sleeve; a plurality of phase-change sleeves are arranged horizontally to form a phase-change material layer; the phase-change material is an inorganic phase-change material, an organic phase-change material or an eutectic mixture of the organic phase-change material; a ventilating layer is arranged between the cement floor and the ground and communicated with the outdoor air by use of a ventilating window; holes formed in the cement floor are communicated with the ventilating floor. A solar thermal collector is joined with the phase-change sleeves by use of a pipeline to form a complete solar water heating system circulation loop. The solar energy and phase-change energy storage material integrated energy self-maintaining building functions in different seasons; in winter, the solar energy system is used for heating the indoor space of the house; in summer, the indoor space of the house is cooled by virtue of natural ventilation; the indoor heat environment is stabilized by use of the phase-change material, the renewable energy sources are utilized to the utmost extent, and the energy consumption of the building is reduced.

The invention discloses an instant hot constant temperature solar energy hot-water system comprising a heat collecting pipe, a water storage tank, an upper water pipe, a lower water pipe, a cold water inlet, a hot water outlet, an electromagnetic valve and a three-way valve, wherein, a meter controller is connected in series between the three-way valve and the hot water outlet; the water storage tank is provided with a water tank water level sensor and a water tank temperature sensor; and the meter controller is provided with a heater, an inlet temperature sensor, an outlet temperature sensor and a flow sensor to distinguish a concentration control system in an electric connection meter controller. The instant hot constant temperature solar energy hot-water system monitors the solar energy heater by utilizing the meter controller with the heater and a plurality of sensors; when the water temperature is not high enough, the heater is automatically started to rapidly heat the lower water, thus ensuring the effluent water to achieve the use temperature; when the water temperature achieves the requirement, the heater is closed, thus saving the energy sources; and when the outside air temperature in winter is too low, the pipe wall heater is automatically started, so as to prevent the water pipe from being frozen to crack, thus leading the solar energy water heater to operate all the time, and making fully use of the solar energy sources.

The invention discloses an air energy heat pump and solar energy complementary type hot water device, which comprises an air energy heat pump, a regenerative heat exchanger, a heat pump heat exchanger, a hot water output heat exchanger, a solar energy hot water heat exchanger, a solar energy hot water circulating pipe, a solar energy heat collector and an expansion water tank, wherein a heating unit of the air energy heat pump is connected with the regenerative heat exchanger, the regenerative heat exchanger is provided with the solar energy hot water heat exchanger and the hot water output heat exchanger, the solar energy hot water heat exchanger is connected with a solar energy heat collector through the solar energy hot water circulating pipe, and a solar energy lower circulating pipeline is connected with the expansion water tank. The air energy heat pump and solar energy complementary type hot water device uses the air energy heat pump and a solar energy hot water system to form a double-energy hot water system, fully uses air heat energy, also change direct using of solar energy hot water into indirect using of the solar energy hot water, increases use rate of air heat energy and exchanges air indoor in time at the same time, keeps air fresh, further guarantees quality of the solar energy hot water, can heat at once when using, prevents bacteria growth, and keeps hot water to be used in health standard.

The invention discloses a housing-concentrated solar water heating system. The system comprises a solar heat collection system and a hot water supply system, wherein the solar water collection system comprises a heat storage water tank applied to concentrated water supply of a plurality of users in the housing; the hot water supply system comprises first hot water pipes, second hot water pipes and end user assistant heating devices; the first hot water pipes are water supply vertical pipes which are communicated with the heat storage water tank; the second hot water pipes are water supply pipes which are communicated with the first hot water pipes and a water supply pipe of single user in the housing; the end user assistant heating devices are distributed in the single user and are communicated with the second hot water pipe for carrying out end assistant heating, thereby forming an open-type single-pipe circulation-free hot water supply system with synergism of the solar heat collection system and the end user assistant heating devices and with removal a hot water returning pipeline; the area of a solar heat collector and the volume of the heat storage tank can be reduced by 50% by changing the design parameters of the system.

The energy source complementary type all-weather solar hot water supply system includes solar heat collector, cold water tank, preheated water tank and hot water tank, microcomputer controller, inlet end and outlet end of micro solar energy heat collector, temp. sensors for temp. in preheated water tank and hot water tank, flow sensor for measuring outlet water flow rate of the heat collector, level sensor of water tank level, water pump and electromagnetic valve which are formed into heat-collecting system of said invention and utilizes the boiler and cold water tank to form the auxiliary energy source heating system of said invention, so that it can raise energy source utilization rate of said system.

The invention discloses a thermal energy comprehensive utilization device for supplying comfortable hot water and generating power through solar energy. The device mainly comprises two parts, namely a solar hot water system and a Rankine cycle system. The device can be adjusted according to a water supply temperature set by a user, water is heated by a solar thermal collector, and effluent of thethermal collector is subjected to thermal energy recovery or cyclic heating. If the temperature of the effluent of the thermal collector is higher than the set water supply temperature, the Rankine cycle system is started to convert high-temperature thermal energy into electric energy; and if a water supply temperature of a water tank on a user side is lower than the set temperature, the water tank of the user is heated through the solar thermal collector, so that the condition that the water tank of the user provides comfortable hot water all the time is ensured. By the device, utilization amount and utilization efficiency of solar energy can be improved, the comfort level of domestic hot water is improved, the solar energy can be comprehensively used for supplying the domestic hot waterand generating the power, and evaporation waste of a water source caused by excessive heat energy is prevented; and the device is suitable for technical upgrade and technical transformation of civil and industrial solar thermal collectors.

A solar hot water system is provided, comprising an ambient temperature sensor, a controller, a valve, a water storage tank, having an inlet and an outlet, and at least a first solar panel, having an inlet in fluid communication with the water storage tank outlet and an outlet in fluid communication with the water storage tank inlet. When the temperature sensor indicates to the controller that the ambient temperature is above a predetermined level, the controller controls the valve to direct flow from the water storage tank outlet to the solar panel inlet and from the solar panel outlet to the water storage tank inlet. When the temperature sensor indicates to the controller that the ambient temperature is below a predetermined level, the controller controls the valve to direct flow from the solar panel inlet to the valve and so to atmosphere.

The invention provides a control method and device for a water heater based on solar energy and air energy. The control method comprises the steps of obtaining the solar energy variation degree of a solar energy water heating system, and adjusting the heating operation time of an air energy water heating system according to the obtained solar energy variation degree, wherein the sum of the hot water quantity obtained by the solar energy water heating system within a preset time t1 and the hot water quantity obtained by the air energy water heating system within the preset time t2 is equal to the hot water quantity preset by a user. According to the technical scheme, the control method and device for the water heater based on solar energy and air energy saves the control cost of the water heater based on solar energy and air energy, and effectively saves power resources.

A collector core for a solar water-heating-system includes a plurality of heat-absorbing pipes each of which surrounds a cooler-water return-pipe. The heating-pipes may connect directly to an insulated hot-water storage-tank from which cooler water descends through the return-pipes into the heating-pipes. Upon reaching the end of the return-pipes, the cooler water flows outward into the space between the surrounding heating-pipes and the inner return-pipes. Upon warming, water between the two pipes rises upward back to the hot-water storage-tank thus completing the thermosyphon flow cycle. Preferably, the inner return-pipe is made of polyvinyl chloride ("PVC"), polybutelene ("PB"), or other compressible material which permits collector core operation both in freezing and non-freezing environments. Alternatively, the collector core may be added to an existing solar water-heating panel to improve its operation.